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Sample records for solar storms affect

  1. Solar noise storms

    CERN Document Server

    Elgaroy, E O

    2013-01-01

    Solar Noise Storms examines the properties and features of solar noise storm phenomenon. The book also presents some theories that can be used to gain a better understanding of the phenomenon. The coverage of the text includes topics that cover the features and behavior of noise storms, such as the observable features of noise storms; the relationship between noise storms and the observable features on the sun; and ordered behavior of storm bursts in the time-frequency plane. The book also covers the spectrum, polarization, and directivity of noise storms. The text will be of great use to astr

  2. The impact of solar flares and magnetic storms on humans

    Energy Technology Data Exchange (ETDEWEB)

    Joselyn, J.A. (NOAA, Space Environment Laboratory, Boulder, CO (United States))

    1992-03-01

    Three classes of solar emanations, namely, photon radiation from solar flares, solar energetic particles, and inhomogeneities in the solar wind that drive magnetic storms, are examined, and their effects on humans and technological systems are discussed. Solar flares may disrupt radio communications in the HF and VLF ranges. Energetic particles pose a special hazard at low-earth orbit and above, where they can penetrate barriers such as spacesuits and aluminum and destroy cells and solid state electronics. Energetic solar particles also influence terrestrial radio waves propagating through polar regions. Magnetic storms may disturb the operation of navigation instruments, power lines and pipelines, and satellites; they give rise to ionospheric storms which affect radio communication at all latitudes. There is also a growing body of evidence that changes in the geomagnetic field affect biological systems. 3 refs.

  3. The impact of solar flares and magnetic storms on humans

    International Nuclear Information System (INIS)

    Joselyn, J.A.

    1992-01-01

    Three classes of solar emanations, namely, photon radiation from solar flares, solar energetic particles, and inhomogeneities in the solar wind that drive magnetic storms, are examined, and their effects on humans and technological systems are discussed. Solar flares may disrupt radio communications in the HF and VLF ranges. Energetic particles pose a special hazard at low-earth orbit and above, where they can penetrate barriers such as spacesuits and aluminum and destroy cells and solid state electronics. Energetic solar particles also influence terrestrial radio waves propagating through polar regions. Magnetic storms may disturb the operation of navigation instruments, power lines and pipelines, and satellites; they give rise to ionospheric storms which affect radio communication at all latitudes. There is also a growing body of evidence that changes in the geomagnetic field affect biological systems. 3 refs

  4. Nuclear magnetohydrodynamic EMP, solar storms, and substorms

    International Nuclear Information System (INIS)

    Rabinowitz, M.; Meliopoulous, A.P.S.; Glytsis, E.N.

    1992-01-01

    In addition to a fast electromagnetic pulse (EMP), a high altitude nuclear burst produces a relatively slow magnetohydrodynamic EMP (MHD EMP), whose effects are like those from solar storm geomagnetically induced currents (SS-GIC). The MHD EMP electric field E approx-lt 10 - 1 V/m and lasts approx-lt 10 2 sec, whereas for solar storms E approx-gt 10 - 2 V/m and lasts approx-gt 10 3 sec. Although the solar storm electric field is lower than MHD EMP, the solar storm effects are generally greater due to their much longer duration. Substorms produce much smaller effects than SS-GIC, but occur much more frequently. This paper describes the physics of such geomagnetic disturbances and analyzes their effects

  5. Solar storms; Tormentas solares

    Energy Technology Data Exchange (ETDEWEB)

    Collaboration: Pereira Cuesta, S.; Pereira Pagan, B.

    2016-08-01

    Solar storms begin with an explosion, or solar flare, on the surface of the sun. The X-rays and extreme ultraviolet radiation from the flare reach the Earths orbit minutes later-travelling at light speed. The ionization of upper layers of our atmosphere could cause radio blackouts and satellite navigation errors (GPS). Soon after, a wave of energetic particles, electrons and protons accelerated by the explosion crosses the orbit of the Earth, and can cause real and significant damage. (Author)

  6. Solar wind drivers of geomagnetic storms during more than four solar cycles

    Directory of Open Access Journals (Sweden)

    Richardson Ian G.

    2012-05-01

    Full Text Available Using a classification of the near-Earth solar wind into three basic flow types: (1 High-speed streams associated with coronal holes at the Sun; (2 Slow, interstream solar wind; and (3 Transient flows originating with coronal mass ejections (CMEs at the Sun, including interplanetary CMEs and the associated upstream shocks and post-shock regions, we determine the drivers of geomagnetic storms of various size ranges based on the Kp index and the NOAA “G” criteria since 1964, close to the beginning of the space era, to 2011, encompassing more than four solar cycles (20–23. We also briefly discuss the occurrence of storms since the beginning of the Kp index in 1932, in the minimum before cycle 17. We note that the extended low level of storm activity during the minimum following cycle 23 is without precedent in this 80-year interval. Furthermore, the “typical” numbers of storm days/cycle quoted in the standard NOAA G storm table appear to be significantly higher than those obtained from our analysis, except for the strongest (G5 storms, suggesting that they should be revised downward.

  7. On the Reduced Geoeffectiveness of Solar Cycle 24: A Moderate Storm Perspective

    Science.gov (United States)

    Selvakumaran, R.; Veenadhari, B.; Akiyama, S.; Pandya, Megha; Gopalswamy, N,; Yashiro, S.; Kumar, Sandeep; Makela, P.; Xie, H.

    2016-01-01

    The moderate and intense geomagnetic storms are identified for the first 77 months of solar cycles 23 and 24. The solar sources responsible for the moderate geomagnetic storms are indentified during the same epoch for both the cycles. Solar cycle 24 has shown nearly 80% reduction in the occurrence of intense storms whereas it is only 40% in case of moderate storms when compared to previous cycle. The solar and interplanetary characteristics of the moderate storms driven by coronal mass ejection (CME) are compared for solar cycles 23 and 24 in order to see reduction in geoeffectiveness has anything to do with the occurrence of moderate storm. Though there is reduction in the occurrence of moderate storms, the Dst distribution does not show much difference. Similarly, the solar source parameters like CME speed, mass, and width did not show any significant variation in the average values as well as the distribution. The correlation between VBz and Dst is determined, and it is found to be moderate with value of 0.68 for cycle 23 and 0.61 for cycle 24. The magnetospheric energy flux parameter epsilon (epsilon) is estimated during the main phase of all moderate storms during solar cycles 23 and 24. The energy transfer decreased in solar cycle 24 when compared to cycle 23. These results are significantly different when all geomagnetic storms are taken into consideration for both the solar cycles.

  8. Solar cycle effect on geomagnetic storms caused by interplanetary magnetic clouds

    Directory of Open Access Journals (Sweden)

    C.-C. Wu

    2006-12-01

    Full Text Available We investigated geomagnetic activity which was induced by interplanetary magnetic clouds during the past four solar cycles, 1965–1998. We have found that the intensity of such geomagnetic storms is more severe in solar maximum than in solar minimum. In addition, we affirm that the average solar wind speed of magnetic clouds is faster in solar maximum than in solar minimum. In this study, we find that solar activity level plays a major role on the intensity of geomagnetic storms. In particular, some new statistical results are found and listed as follows. (1 The intensity of a geomagnetic storm in a solar active period is stronger than in a solar quiet period. (2 The magnitude of negative Bzmin is larger in a solar active period than in a quiet period. (3 Solar wind speed in an active period is faster than in a quiet period. (4 VBsmax in an active period is much larger than in a quiet period. (5 Solar wind parameters, Bzmin, Vmax and VBsmax are correlated well with geomagnetic storm intensity, Dstmin during a solar active period. (6 Solar wind parameters, Bzmin, and VBsmax are not correlated well (very poorly for Vmax with geomagnetic storm intensity during a solar quiet period. (7 The speed of the solar wind plays a key role in the correlation of solar wind parameters vs. the intensity of a geomagnetic storm. (8 More severe storms with Dstmin≤−100 nT caused by MCs occurred in the solar active period than in the solar quiet period.

  9. The extreme solar storm of May 1921: observations and a complex topological model

    Directory of Open Access Journals (Sweden)

    H. Lundstedt

    2015-01-01

    Full Text Available A complex solid torus model was developed in order to be able to study an extreme solar storm, the so-called "Great Storm" or "New York Railroad Storm" of May 1921, when neither high spatial and time resolution magnetic field measurements, solar flare nor coronal mass ejection observations were available. We suggest that a topological change happened in connection with the occurrence of the extreme solar storm. The solar storm caused one of the most severe space weather effects ever.

  10. Solar wind-magnetosphere coupling during intense magnetic storms (1978-1979)

    Science.gov (United States)

    Gonzalez, Walter D.; Gonzalez, Alicia L. C.; Tsurutani, Bruce T.; Smith, Edward J.; Tang, Frances

    1989-01-01

    The solar wind-magnetosphere coupling problem during intense magnetic storms was investigated for ten intense magnetic storm events occurring between August 16, 1978 to December 28, 1979. Particular attention was given to the dependence of the ring current energization on the ISEE-measured solar-wind parameters and the evolution of the ring current during the main phase of the intense storms. Several coupling functions were tested as energy input, and several sets of the ring current decay time-constant were searched for the best correlation with the Dst response. Results indicate that a large-scale magnetopause reconnection operates during an intense storm event and that the solar wind ram pressure plays an important role in the energization of the ring current.

  11. Coronal mass ejections and disturbances in solar wind plasma parameters in relation with geomagnetic storms

    International Nuclear Information System (INIS)

    Verma, P L; Singh, Puspraj; Singh, Preetam

    2014-01-01

    Coronal Mass Ejections (CMEs) are the drastic solar events in which huge amount of solar plasma materials are ejected into the heliosphere from the sun and are mainly responsible to generate large disturbances in solar wind plasma parameters and geomagnetic storms in geomagnetic field. We have studied geomagnetic storms, (Dst ≤-75 nT) observed during the period of 1997-2007 with Coronal Mass Ejections and disturbances in solar wind plasma parameters (solar wind temperature, velocity, density and interplanetary magnetic field) .We have inferred that most of the geomagnetic storms are associated with halo and partial halo Coronal Mass Ejections (CMEs).The association rate of halo and partial halo coronal mass ejections are found 72.37 % and 27.63 % respectively. Further we have concluded that geomagnetic storms are closely associated with the disturbances in solar wind plasma parameters. We have determined positive co-relation between magnitudes of geomagnetic storms and magnitude of jump in solar wind plasma temperature, jump in solar wind plasma density, jump in solar wind plasma velocity and jump in average interplanetary magnetic field with co-relation co-efficient 0 .35 between magnitude of geomagnetic storms and magnitude of jump in solar wind plasma temperature, 0.19 between magnitude of geomagnetic storms and magnitude of jump in solar wind density, 0.34 between magnitude of geomagnetic storms and magnitude of jump in solar wind plasma velocity, 0.66 between magnitude of geomagnetic storms and magnitude of jump in average interplanetary magnetic field respectively. We have concluded that geomagnetic storms are mainly caused by Coronal Mass Ejections and disturbances in solar wind plasma parameters that they generate.

  12. The 2015 Summer Solstice Storm: One of the Major Geomagnetic Storms of Solar Cycle 24 Observed at Ground Level

    Science.gov (United States)

    Augusto, C. R. A.; Navia, C. E.; de Oliveira, M. N.; Nepomuceno, A. A.; Raulin, J. P.; Tueros, E.; de Mendonça, R. R. S.; Fauth, A. C.; Vieira de Souza, H.; Kopenkin, V.; Sinzi, T.

    2018-05-01

    We report on the 22 - 23 June 2015 geomagnetic storm that occurred at the summer solstice. There have been fewer intense geomagnetic storms during the current solar cycle, Solar Cycle 24, than in the previous cycle. This situation changed after mid-June 2015, when one of the largest solar active regions (AR 12371) of Solar Cycle 24 that was located close to the central meridian, produced several coronal mass ejections (CMEs) associated with M-class flares. The impact of these CMEs on the Earth's magnetosphere resulted in a moderate to severe G4-class geomagnetic storm on 22 - 23 June 2015 and a G2 (moderate) geomagnetic storm on 24 June. The G4 solstice storm was the second largest (so far) geomagnetic storm of Cycle 24. We highlight the ground-level observations made with the New-Tupi, Muonca, and the CARPET El Leoncito cosmic-ray detectors that are located within the South Atlantic Anomaly (SAA) region. These observations are studied in correlation with data obtained by space-borne detectors (ACE, GOES, SDO, and SOHO) and other ground-based experiments. The CME designations are taken from the Computer Aided CME Tracking (CACTus) automated catalog. As expected, Forbush decreases (FD) associated with the passing CMEs were recorded by these detectors. We note a peculiar feature linked to a severe geomagnetic storm event. The 21 June 2015 CME 0091 (CACTus CME catalog number) was likely associated with the 22 June summer solstice FD event. The angular width of CME 0091 was very narrow and measured {˜} 56° degrees seen from Earth. In most cases, only CME halos and partial halos lead to severe geomagnetic storms. We perform a cross-check analysis of the FD events detected during the rise phase of Solar Cycle 24, the geomagnetic parameters, and the CACTus CME catalog. Our study suggests that narrow angular-width CMEs that erupt in a westward direction from the Sun-Earth line can lead to moderate and severe geomagnetic storms. We also report on the strong solar proton

  13. Solar Wind Charge Exchange During Geomagnetic Storms

    Science.gov (United States)

    Robertson, Ina P.; Cravens, Thomas E.; Sibeck, David G.; Collier, Michael R.; Kuntz, K. D.

    2012-01-01

    On March 31st. 2001, a coronal mass ejection pushed the subsolar magnetopause to the vicinity of geosynchronous orbit at 6.6 RE. The NASA/GSFC Community Coordinated Modeling Center (CCMe) employed a global magnetohydrodynamic (MHD) model to simulate the solar wind-magnetosphere interaction during the peak of this geomagnetic storm. Robertson et aL then modeled the expected 50ft X-ray emission due to solar wind charge exchange with geocoronal neutrals in the dayside cusp and magnetosheath. The locations of the bow shock, magnetopause and cusps were clearly evident in their simulations. Another geomagnetic storm took place on July 14, 2000 (Bastille Day). We again modeled X-ray emission due to solar wind charge exchange, but this time as observed from a moving spacecraft. This paper discusses the impact of spacecraft location on observed X-ray emission and the degree to which the locations of the bow shock and magnetopause can be detected in images.

  14. SOLAR ENERGETIC PARTICLE EVENT ASSOCIATED WITH THE 2012 JULY 23 EXTREME SOLAR STORM

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Bei; Liu, Ying D.; Hu, Huidong; Wang, Rui; Yang, Zhongwei [State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190 (China); Luhmann, Janet G., E-mail: liuxying@spaceweather.ac.cn [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States)

    2016-08-20

    We study the solar energetic particle (SEP) event associated with the 2012 July 23 extreme solar storm, for which Solar Terrestrial Relations Observatory (STEREO) and the spacecraft at L1 provide multi-point remote sensing and in situ observations. The extreme solar storm, with a superfast shock and extremely enhanced ejecta magnetic fields observed near 1 au at STEREO A , was caused by the combination of successive coronal mass ejections (CMEs). Meanwhile, energetic particles were observed by STEREO and near-Earth spacecraft such as the Advanced Composition Explorer and SOlar and Heliospheric Observatory , suggesting a wide longitudinal spread of the particles at 1 au. Combining the SEP observations with in situ plasma and magnetic field measurements, we investigate the longitudinal distribution of the SEP event in connection with the associated shock and CMEs. Our results underscore the complex magnetic configuration of the inner heliosphere formed by solar eruptions. Examination of particle intensities, proton anisotropy distributions, element abundance ratios, magnetic connectivity, and spectra also gives important clues for particle acceleration, transport, and distribution.

  15. On the statistics of the largest geomagnetic storms per solar cycle

    International Nuclear Information System (INIS)

    Siscoe, G.L.

    1976-01-01

    The theory of extreme value statistics is applied to the first, second, and third largest geomagnetic storms in nine solar cycles measured by the average half-daily aa indices compiled by Mayaud. Analytic expressions giving the probability of the extremes per solar cycle as a contour function of storm magnitude are obtained by least squares fitting of the observations to the appropriate theoretical extreme value probability functions. The results are used to obtain the statistical characteristics (mode, median, mean, and standard deviation) for the extreme values. The results are applied to find the expected range of extreme values in a set as a function of the number of solar cycles in the set. We find that the expected range of the largest storm is quite narrow and is larger for the second and third largest storms. The observed range of the extreme half-daily aa index for the nine solar cycles is 354--546 γ. In a set of 100 cycles the range is expanded esentially to 311--680γ, an increase of only 39% in the range. The result supports the argument for a change in solar cycle statistics in the latter part of the Seventeenth Century (the Maunder minimum)

  16. Solar wind-magnetosphere coupling during intense magnetic storms (1978--1979)

    International Nuclear Information System (INIS)

    Gonzalez, W.D.; Tsurutani, B.T.; Gonzalez, A.L.C.; Smith, E.J.; Tang, F.; Akasofu, S.

    1989-01-01

    The solar wind-magnetosphere coupling problem is investigated for the ten intense magnetic storms (Dst <-100 nT) that occurred during the 500 days (August 16, 1978 to December 28, 1979) studied by Gonzalez and Tsurutani [1987]. This investigation concentrates on the ring current energization in terms of solar wind parameters, in order to explain the | -Dst | growth observed during these storms. Thus several coupling functions are tested as energy input and several sets of the ring current decay time-constant τ are searched to find best correlations with the Dst response. From the fairly large correlation coefficients found in this study, there is strong evidence that large scale magnetopause reconnection operates during such intense storm events and that the solar wind ram pressure plays an important role in the ring current energization. Thus a ram pressure correction factor is suggested for expressions concerning the reconnection power during time intervals with large ram pressure variations

  17. A synoptic study of geomagnetic storms and related solar phenomena during 1976 through 1978

    International Nuclear Information System (INIS)

    Marubashi, K.

    1979-01-01

    An attempt has been made to identify the causes of geomagnetic storms which occurred during the three year period from 1976 through 1978. Of the 114 storms with D sub(st) = 25 investigated in this paper, 52 storms are found to be caused by corotating streams, 16 storms by solar flares, and 19 storms by compound effects of both corotating streams and flares. The causes of the remaining 27 storms could not be identified. By examining the characteristics of those solar flares which were taken to be responsible for geomagnetic storms, a semiquantitative conclusion has been obtained about the criteria for the flares which can produce magnetic storms. In addition, clear semiannual variation has been found in geomagnetic activity caused by flare-free corotating streams. (author)

  18. Morphology of geomagnetic storms, recorded at Hurbanovo, and its relation to solar activity

    International Nuclear Information System (INIS)

    Ochabova, P.; Psenakova, M.

    1977-01-01

    The morphological structure of geomagnetic storms was investigated using the data on 414 storms, recorded in the years 1949 to 1968 at the Geomagnetic Observatory of Hurbanovo (phi=47.9 deg N, lambda=18.2 deg E). These data also formed a suitable basis for investigating the effect of the solar activity on the characteristic features of storms. The storm-time variation of the geomagnetic field was considered after the Sq-variation had been eliminated. The sets of storms, i.e. 263 storms recorded at a time of high sunspot activity and 151 storms recorded at a time of low activity, were divided into 7 groups, depending on the duration of their initial phase. In 92% of the investigated storms the increase in the horizontal component lasted from 0 to 15 hrs. The effect of the solar activity was markedly reflected in the occurrence of very severe storms, as well as in the maximum decrease in the H-component in the main phase. This can also be seen in the rate at which the storms recover. (author)

  19. Two-Step Forecast of Geomagnetic Storm Using Coronal Mass Ejection and Solar Wind Condition

    Science.gov (United States)

    Kim, R.-S.; Moon, Y.-J.; Gopalswamy, N.; Park, Y.-D.; Kim, Y.-H.

    2014-01-01

    To forecast geomagnetic storms, we had examined initially observed parameters of coronal mass ejections (CMEs) and introduced an empirical storm forecast model in a previous study. Now we suggest a two-step forecast considering not only CME parameters observed in the solar vicinity but also solar wind conditions near Earth to improve the forecast capability. We consider the empirical solar wind criteria derived in this study (Bz = -5 nT or Ey = 3 mV/m for t = 2 h for moderate storms with minimum Dst less than -50 nT) (i.e. Magnetic Field Magnitude, B (sub z) less than or equal to -5 nanoTeslas or duskward Electrical Field, E (sub y) greater than or equal to 3 millivolts per meter for time greater than or equal to 2 hours for moderate storms with Minimum Disturbance Storm Time, Dst less than -50 nanoTeslas) and a Dst model developed by Temerin and Li (2002, 2006) (TL [i.e. Temerin Li] model). Using 55 CME-Dst pairs during 1997 to 2003, our solar wind criteria produce slightly better forecasts for 31 storm events (90 percent) than the forecasts based on the TL model (87 percent). However, the latter produces better forecasts for 24 nonstorm events (88 percent), while the former correctly forecasts only 71 percent of them. We then performed the two-step forecast. The results are as follows: (i) for 15 events that are incorrectly forecasted using CME parameters, 12 cases (80 percent) can be properly predicted based on solar wind conditions; (ii) if we forecast a storm when both CME and solar wind conditions are satisfied (n, i.e. cap operator - the intersection set that is comprised of all the elements that are common to both), the critical success index becomes higher than that from the forecast using CME parameters alone, however, only 25 storm events (81 percent) are correctly forecasted; and (iii) if we forecast a storm when either set of these conditions is satisfied (?, i.e. cup operator - the union set that is comprised of all the elements of either or both

  20. Distant Tail Behavior During High Speed Solar Wind Streams and Magnetic Storms

    Science.gov (United States)

    Ho, C. M.; Tsurutani, B. T.

    1997-01-01

    We have examined the ISEE 3 distant tail data during three intense magnetic storms and have identified the tail response to high-speed solar wind streams, interplanetary magnetic clouds, and near-Earth storms.

  1. Storms

    International Nuclear Information System (INIS)

    Kai, Keizo; Melrose, D.B.; Suzuki, S.

    1985-01-01

    At metre and decametre wavelengths long-lasting solar radio emission, consisting of thousands of short-lived spikes superimposed on a slowly varying continuum, is observed. This type of storm emission may continue for periods ranging from a few hours to several days; the long duration is one of the characteristics which distinguish storms from other types of solar radio emission. These events are called storms or noise storms by analogy with geomagnetic storms. (author)

  2. Variation of Magnetic Field (By , Bz) Polarity and Statistical Analysis of Solar Wind Parameters during the Magnetic Storm Period

    OpenAIRE

    Ga-Hee Moon

    2011-01-01

    It is generally believed that the occurrence of a magnetic storm depends upon the solar wind conditions, particularly the southward interplanetary magnetic field (IMF) component. To understand the relationship between solar wind parameters and magnetic storms, variations in magnetic field polarity and solar wind parameters during magnetic storms are examined. A total of 156 storms during the period of 1997~2003 are used. According to the interplanetary driver, magnetic storms are ...

  3. SOLAR RADIO TYPE-I NOISE STORM MODULATED BY CORONAL MASS EJECTIONS

    International Nuclear Information System (INIS)

    Iwai, K.; Tsuchiya, F.; Morioka, A.; Misawa, H.; Miyoshi, Y.; Masuda, S.; Shimojo, M.; Shiota, D.; Inoue, S.

    2012-01-01

    The first coordinated observations of an active region using ground-based radio telescopes and the Solar Terrestrial Relations Observatory (STEREO) satellites from different heliocentric longitudes were performed to study solar radio type-I noise storms. A type-I noise storm was observed between 100 and 300 MHz during a period from 2010 February 6 to 7. During this period the two STEREO satellites were located approximately 65° (ahead) and –70° (behind) from the Sun-Earth line, which is well suited to observe the earthward propagating coronal mass ejections (CMEs). The radio flux of the type-I noise storm was enhanced after the preceding CME and began to decrease before the subsequent CME. This time variation of the type-I noise storm was directly related to the change of the particle acceleration processes around its source region. Potential-field source-surface extrapolation from the Solar and Heliospheric Observatory/Michelson Doppler Imager (SOHO/MDI) magnetograms suggested that there was a multipolar magnetic system around the active region from which the CMEs occurred around the magnetic neutral line of the system. From our observational results, we suggest that the type-I noise storm was activated at a side-lobe reconnection region that was formed after eruption of the preceding CME. This magnetic structure was deformed by a loop expansion that led to the subsequent CME, which then suppressed the radio burst emission.

  4. Statistical Characteristics of Solar Wind Dynamic Pressure Enhancements During Geomagnetic Storms

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    C.-R. Choi

    2008-06-01

    Full Text Available Solar wind dynamic pressure enhancements are known to cause various types of disturbances to the magnetosphere. In particular, dynamic pressure enhancements may affect the evolution of magnetic storms when they occur during storm times. In this paper, we have investigated the statistical significance and features of dynamic pressure enhancements during magnetic storm times. For the investigation, we have used a total of 91 geomagnetic storms for 2001-2003, for which the Dst minimum (Dst_min is below -50 nT. Also, we have imposed a set of selection criteria for a pressure enhancement to be considered an event: The main selection criterion is that the pressure increases by ≥50% or ≥3nPa within 30 min and remains to be elevated for 10 min or longer. For our statistical analysis, we define the storm time to be the interval from the main Dst decrease, through Dst_min, to the point where the Dst index recovers by 50%. Our main results are summarized as follows. (i ~81% of the studied storms indicate at least one event of pressure enhancements. When averaged over all the 91 storms, the occurrence rate is 4.5 pressure enhancement events per storm and 0.15 pressure enhancement events per hour. (ii The occurrence rate of the pressure enhancements is about three times higher for CME-driven storm times than for CIR-driven storm times. (iii Only 21.1% of the pressure enhancements show a clear association with an interplanetary shock. (iv A large number of the pressure enhancement events are accompanied with a simultaneous change of IMF By and/or Bz: For example, 73.5% of the pressure enhancement events are associated with an IMF change of either |∆Bz|>2nT or |∆By|>2nT. This last finding suggests that one should consider possible interplay effects between the simultaneous pressure and IMF changes in many situations.

  5. Polarization reversal during the solar noise storm activity of August 1971

    International Nuclear Information System (INIS)

    Kurihara, Masahiro

    1975-01-01

    Reversals of the sense of circular polarization of solar radio emission were observed for active type I storms in August 1971. Observations with a 160-MHz interferometer revealed that the reversals were caused by sudden growth and decay of a secondary storm source whose sense of polarization was opposite to that of the long-lasting main source. The time variations of both the associated S-component sources and sunspots are compared with that of the storm sources. The role of the magnetic field, which presumably connects the storm sources, the S-component sources, and the sunspots, is discussed in relation to the origin of the storm activity. (author)

  6. Variation of Magnetic Field (By , Bz Polarity and Statistical Analysis of Solar Wind Parameters during the Magnetic Storm Period

    Directory of Open Access Journals (Sweden)

    Ga-Hee Moon

    2011-06-01

    Full Text Available It is generally believed that the occurrence of a magnetic storm depends upon the solar wind conditions, particularly the southward interplanetary magnetic field (IMF component. To understand the relationship between solar wind parameters and magnetic storms, variations in magnetic field polarity and solar wind parameters during magnetic storms are examined. A total of 156 storms during the period of 1997~2003 are used. According to the interplanetary driver, magnetic storms are divided into three types, which are coronal mass ejection (CME-driven storms, co-rotating interaction region (CIR-driven storms, and complicated type storms. Complicated types were not included in this study. For this purpose, the manner in which the direction change of IMF By and Bz components (in geocentric solar magnetospheric coordinate system coordinate during the main phase is related with the development of the storm is examined. The time-integrated solar wind parameters are compared with the time-integrated disturbance storm time (Dst index during the main phase of each magnetic storm. The time lag with the storm size is also investigated. Some results are worth noting: CME-driven storms, under steady conditions of Bz < 0, represent more than half of the storms in number. That is, it is found that the average number of storms for negative sign of IMF Bz (T1~T4 is high, at 56.4%, 53.0%, and 63.7% in each storm category, respectively. However, for the CIR-driven storms, the percentage of moderate storms is only 29.2%, while the number of intense storms is more than half (60.0% under the Bz < 0 condition. It is found that the correlation is highest between the time-integrated IMF Bz and the time-integrated Dst index for the CME-driven storms. On the other hand, for the CIR-driven storms, a high correlation is found, with the correlation coefficient being 0.93, between time-integrated Dst index and time-integrated solar wind speed, while a low correlation, 0.51, is

  7. Time Delay Between Dst Index and Magnetic Storm Related Structure in the Solar Wind

    Science.gov (United States)

    Osherovich, Vladimir A.; Fainberg, Joseph

    2015-01-01

    Benson et al. (2015, this volume) selected 10 large magnetic storms, with associated Dst minimum values less than or equal to -100 nT, for which high-latitude topside ionospheric electron density profiles are available from topside-sounder satellites. For these 10 storms, we performed a superposition of Dst and interplanetary parameters B, v, N(sub p) and T(sub p). We have found that two interplanetary parameters, namely B and v, are sufficient to reproduce Dst with correlation coefficient cc approximately 0.96 provided that the interplanetary parameter times are taken 0.15 days earlier than the associated Dst times. Thus we have found which part of the solar wind is responsible for each phase of the magnetic storm. This result is also verified for individual storms as well. The total duration of SRS (storm related structure in the solar wind) is 4 - 5 days which is the same as the associated Dst interval of the magnetic storm.

  8. Solar Wind Features Responsible for Magnetic Storms and Substorms During the Declining Phase of the Solar Cycle: 197

    Science.gov (United States)

    Tsurutani, B.; Arballo, J.

    1994-01-01

    We examine interplanetary data and geomagnetic activity indices during 1974 when two long-lasting solar wind corotating streams existed. We find that only 3 major storms occurred during 1974, and all were associated with coronal mass ejections. Each high speed stream was led by a shock, so the three storms had sudden commencements. Two of the 1974 major storms were associated with shock compression of preexisting southward fields and one was caused by southward fields within a magnetic cloud. Corotating streams were responsible for recurring moderate to weak magnetic storms.

  9. What is the Relationship between the Solar Wind and Storms/Substorms?

    Science.gov (United States)

    Fairfield, D. H.; Burlaga, L. F.

    1999-01-01

    The interplanetary magnetic field (IMF) carried past the Earth by the solar wind has long been known to be the principal quantity that controls geomagnetic storms and substorms. Intervals of strong southward IMF with durations of at least a significant fraction of a day produce storms, while more typical, shorter intervals of less-intense southward fields produce substorms. The strong, long-duration southward fields are generally associated with coronal mass ejections and magnetic clouds or else they are produced by interplanetary dynamics initiated by fast solar wind flows that compress preexisting southward fields. Smaller, short-duration southward fields that occur on most days are related to long period waves, turbulence, or random variations in the IMF. Southward IMF enhances dayside reconnection between the IMF and the Earth's dipole with the reconnected field lines supplementing open field lines of the geomagnetic tail and producing an expanded polar cap and increased tail energy. Although the frequent storage of solar wind energy and its release during substorms is the most common mode of solar wind/magnetosphere interaction, under certain circumstances, steady southward IMF seems to produce intervals of relatively steady magnetosphere convection without substorms. During these latter times, the inner magnetosphere remains in a stressed tail-like state while the more distant magnetotail has larger northward field and more dipolar-like field lines. Recent evidence suggests that enhanced magnetosphere particle densities associated with enhanced solar wind densities allow more particles to be accelerated for the ring current, thus creating larger storms.

  10. (abstract) The Distant Tail Behavior During High Speed Solar Wind Streams and Magnetic Storms

    Science.gov (United States)

    Ho, C. M.; Tsurutani, B. T.

    1996-01-01

    We have examined the ISEE-3 distant tail data during three intense magnetic storms and have identified the tail response to high speed solar wind streams, interplanetary magnetic clouds, and near-Earth storms.

  11. Geomagnetic storm forecasting service StormFocus: 5 years online

    Science.gov (United States)

    Podladchikova, Tatiana; Petrukovich, Anatoly; Yermolaev, Yuri

    2018-04-01

    Forecasting geomagnetic storms is highly important for many space weather applications. In this study, we review performance of the geomagnetic storm forecasting service StormFocus during 2011-2016. The service was implemented in 2011 at SpaceWeather.Ru and predicts the expected strength of geomagnetic storms as measured by Dst index several hours ahead. The forecast is based on L1 solar wind and IMF measurements and is updated every hour. The solar maximum of cycle 24 is weak, so most of the statistics are on rather moderate storms. We verify quality of selection criteria, as well as reliability of real-time input data in comparison with the final values, available in archives. In real-time operation 87% of storms were correctly predicted while the reanalysis running on final OMNI data predicts successfully 97% of storms. Thus the main reasons for prediction errors are discrepancies between real-time and final data (Dst, solar wind and IMF) due to processing errors, specifics of datasets.

  12. The Ring Current Response to Solar and Interplanetary Storm Drivers

    Science.gov (United States)

    Mouikis, C.; Kistler, L. M.; Bingham, S.; Kronberg, E. A.; Gkioulidou, M.; Huang, C. L.; Farrugia, C. J.

    2014-12-01

    The ring current responds differently to the different solar and interplanetary storm drivers such as coronal mass injections, (CME's), corotating interaction regions (CIR's), high-speed streamers and other structures. The resulting changes in the ring current particle pressure, in turn, change the global magnetic field, controlling the transport of the radiation belts. To quantitatively determine the field changes during a storm throughout the magnetosphere, it is necessary to understand the transport, sources and losses of the particles that contribute to the ring current. Because the measured ring current energy spectra depend not only on local processes, but also on the history of the ions along their entire drift path, measurements of ring current energy spectra at two or more locations can be used to strongly constrain the time dependent magnetic and electric fields. In this study we use data predominantly from the Cluster and the Van Allen Probes, covering more than a full solar cycle (from 2001 to 2014). For the period 2001-2012, the Cluster CODIF and RAPID measurements of the inner magnetosphere are the primary data set used to monitor the storm time ring current variability. After 2012, the Cluster data set complements the data from the Van Allen Probes HOPE and RBSPICE instruments, providing additional measurements from different MLT and L shells. Selected storms from this periods, allow us to study the ring current dynamics and pressure changes, as a function of L shell, magnetic local time, and the type of interplanetary disturbances.

  13. Low-dimensionality and predictability of solar wind and global magnetosphere during magnetic storms

    OpenAIRE

    Zivkovic, Tatjana; Rypdal, Kristoffer

    2011-01-01

    This article is part of Tatjana Živkovics' doctoral thesis. Available in Munin at http://hdl.handle.net/10037/3231 The storm index SYM-H, the solar wind velocity v, and interplanetary magnetic field Bz show no signatures of low-dimensional dynamics in quiet periods, but tests for determinism in the time series indicate that SYM-H exhibits a significant low-dimensional component during storm time, suggesting that self-organization takes place during magnetic storms. Even though our analysis...

  14. Overview of on-board measurements during solar storm periods

    Czech Academy of Sciences Publication Activity Database

    Beck, P.; Dyer, C.; Fuller, N.; Hands, A.; Latocha, M.; Rollet, S.; Spurný, František

    2009-01-01

    Roč. 136, č. 4 (2009), s. 297-303 ISSN 0144-8420 R&D Projects: GA ČR GA205/09/0171 Institutional research plan: CEZ:AV0Z10480505 Keywords : solar storm * aircraft crew * cosmic radiation Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.707, year: 2009

  15. The Distant Tail Behavior During High Speed Solar Wind Streams and Magnetic Storms

    Science.gov (United States)

    Ho, C. M.; Tsurutani, B. T.

    1996-01-01

    We have examined the ISEE-3 distant tail data during three intense (Dststorms and have identified the tail response to high speed solar wind streams, interplanetary magnetic clouds, and near-Earth storms. The three storms have a peak Dst ranging from -150 to -220 nT, and occur on Jan. 9, Feb. 4, and Aug. 8, 1993.

  16. Solar flare effects and storm sudden commencement even in ...

    African Journals Online (AJOL)

    1998-05-08

    Variations in the three components of geomagnetic field were observed at the twenty-two geomagnetic Euro-African Observatories during the solar flare that occurred on the 6 May, 1998 at 0080UT and storm sudden commencement that took place on May 8, 1998 at 15.00 UT. The geomagnetic field on 6 May, 1998 was ...

  17. Current understanding of magnetic storms: Storm-substorm relationships

    International Nuclear Information System (INIS)

    Kamide, Y.; Gonzalez, W.D.; Baumjohann, W.; Daglis, I.A.; Grande, M.; Joselyn, J.A.; Singer, H.J.; McPherron, R.L.; Phillips, J.L.; Reeves, E.G.; Rostoker, G.; Sharma, A.S.; Tsurutani, B.T.

    1998-01-01

    This paper attempts to summarize the current understanding of the storm/substorm relationship by clearing up a considerable amount of controversy and by addressing the question of how solar wind energy is deposited into and is dissipated in the constituent elements that are critical to magnetospheric and ionospheric processes during magnetic storms. (1) Four mechanisms are identified and discussed as the primary causes of enhanced electric fields in the interplanetary medium responsible for geomagnetic storms. It is pointed out that in reality, these four mechanisms, which are not mutually exclusive, but interdependent, interact differently from event to event. Interplanetary coronal mass ejections (ICMEs) and corotating interaction regions (CIRs) are found to be the primary phenomena responsible for the main phase of geomagnetic storms. The other two mechanisms, i.e., HILDCAA (high-intensity, long-duration, continuous auroral electrojet activity) and the so-called Russell-McPherron effect, work to make the ICME and CIR phenomena more geoeffective. The solar cycle dependence of the various sources in creating magnetic storms has yet to be quantitatively understood. (2) A serious controversy exists as to whether the successive occurrence of intense substorms plays a direct role in the energization of ring current particles or whether the enhanced electric field associated with southward IMF enhances the effect of substorm expansions. While most of the Dst variance during magnetic storms can be solely reproduced by changes in the large-scale electric field in the solar wind and the residuals are uncorrelated with substorms, recent satellite observations of the ring current constituents during the main phase of magnetic storms show the importance of ionospheric ions. This implies that ionospheric ions, which are associated with the frequent occurrence of intense substorms, are accelerated upward along magnetic field lines, contributing to the energy density of the

  18. Dynamics of the Solar Wind Electromagnetic Energy Transmission Into Magnetosphere during Large Geomagnetic Storms

    Science.gov (United States)

    Kuznetsova, Tamara; Laptukhov, Alexej; Petrov, Valery

    Causes of the geomagnetic activity (GA) in the report are divided into temporal changes of the solar wind parameters and the changes of the geomagnetic moment orientation relative directions of the solar wind electric and magnetic fields. Based on our previous study we concluded that a reconnection based on determining role of mutual orientation of the solar wind electric field and geomagnetic moment taking into account effects of the Earth's orbital and daily motions is the most effective compared with existing mechanisms. At present a reconnection as paradigma that has applications in broad fields of physics needs analysis of experimental facts to be developed. In terms of reconnection it is important not only mutual orientation of vectors describing physics of interaction region but and reconnection rate which depends from rate of energy flux to those regions where the reconnection is permitted. Applied to magnetosphere these regions first of all are dayside magnetopause and polar caps. Influence of rate of the energy flux to the lobe magnetopause (based on calculations of the Poyting electromagnetic flux component controlling the reconnection rate along the solar wind velocity Pv) on planetary GA (Dst, Kp indices) is investigated at different phases of geomagnetic storms. We study also the rate of energy flux to the polar caps during storms (based on calculations of the Poyting flux vector component along the geomagnetic moment Pm) and its influence on magnetic activity in the polar ionosphere: at the auroral zone (AU,AL indices). Results allow to evaluate contributions of high and low latitude sources of electromagnetic energy to the storm development and also to clear mechanism of the electromagnetic energy transmission from the solar wind to the magnetosphere. We evaluate too power of the solar wind electromagnetic energy during well-known large storms and compare result with power of the energy sources of other geophysical processes (atmosphere, ocean

  19. Solar sources of interplanetary southward B/sub z/ events responsible for major magnetic storms (1978--1979)

    International Nuclear Information System (INIS)

    Tang, F.; Tsurutani, B.T.; Gonzalez, W.D.; Akasofu, S.I.; Smith, E.J.

    1989-01-01

    Tsurutani et al. [1988] analyzed the 10 intense interplanetary southward B/sub z/ events that led to major magnetic storms (Dst 3.0) are associated with prominence eruptions. For three of the five southward B/sub z/ events in which the driver gases are the causes of the intense southward field leading to magnetic storms, the photospheric fields of the solar sources have no dominant southward component, indicating the driver gas fields do not always result from a simple outward convection of solar magnetic fields. Finally we compare the solar events and their resulting interplanetary shocks and find that the standard solar parameters do not correlate with the strengths of the resulting shocks at 1 AU. The implications are discussed. copyright American Geophysical Union 1989

  20. EFFECTS OF ALFVEN WAVES ON ELECTRON CYCLOTRON MASER EMISSION IN CORONAL LOOPS AND SOLAR TYPE I RADIO STORMS

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, G. Q.; Chen, L.; Wu, D. J. [Purple Mountain Observatory, CAS, Nanjing 210008 (China); Yan, Y. H., E-mail: djwu@pmo.ac.cn [Key Laboratory of Solar Activity, National Astronomical Observatories, CAS, Beijing 100012 (China)

    2013-06-10

    Solar type I radio storms are long-lived radio emissions from the solar atmosphere. It is believed that these type I storms are produced by energetic electrons trapped within a closed magnetic structure and are characterized by a high ordinary (O) mode polarization. However, the microphysical nature of these emissions is still an open problem. Recently, Wu et al. found that Alfven waves (AWs) can significantly influence the basic physics of wave-particle interactions by modifying the resonant condition. Taking the effects of AWs into account, this work investigates electron cyclotron maser emission driven by power-law energetic electrons with a low-energy cutoff distribution, which are trapped in coronal loops by closed solar magnetic fields. The results show that the emission is dominated by the O mode. It is proposed that this O mode emission may possibly be responsible for solar type I radio storms.

  1. The solar wind control of electron fluxes in geostationary orbit during magnetic storms

    International Nuclear Information System (INIS)

    Popov, G.V.; Degtyarev, V.I.; Sheshukov, S.S.; Chudnenko, S.E.

    1999-01-01

    The dynamics of electron fluxes (with energies from 30 to 1360 keV) in geostationary orbit during magnetic storms was investigated on the basis of LANL spacecraft 1976-059 and 1977-007 data. Thirty-seven magnetic storms with distinct onsets from the time interval July 1976-December 1978 were used in the analysis. A treatment of experimental data involved the moving averaging and the overlapping epoch method. The smoothed component of electron fluxes represents mainly trapped electrons and shows their strong dependence on the solar wind velocity. The time lag between a smoothed electron flux and the solar wind velocity increases with electron energy reflecting dynamics of the inner magnetosphere filling with trapped energetic electrons originating from substorm injection regions located not far outside geostationary orbit

  2. Predicting the occurrence of super-storms

    Directory of Open Access Journals (Sweden)

    N. Srivastava

    2005-11-01

    Full Text Available A comparative study of five super-storms (Dst<-300 nT of the current solar cycle after the launch of SoHO, to identify solar and interplanetary variables that influence the magnitude of resulting geomagnetic storms, is described. Amongst solar variables, the initial speed of a CME is considered the most reliable predictor of the strength of the associated geomagnetic storm because fast mass ejections are responsible for building up the ram pressure at the Earth's magnetosphere. However, although most of the super-storms studied were associated with high speed CMEs, the Dst index of the resulting geomagnetic storms varied between -300 to -472 nT. The most intense storm of 20 November 2003, (Dst ~ -472 nT had its source in a comparatively smaller active region and was associated with a relatively weaker, M-class flare while all other super-storms had their origins in large active regions and were associated with strong X-class flares. However, this superstorm did not show any associated extraordinary solar and interplanetary characteristics. The study also reveals the challenge in the reliable prediction of the magnitude of a geomagnetic storm from solar and interplanetary variables.

  3. The solar activity, magnetic storms and their effects on biological systems

    International Nuclear Information System (INIS)

    Salakhitdinova, M.K.; Yusupov, A.A.

    2004-01-01

    In the present time much attention is spent on the electromagnetic waves, solar radiation and magnetic storms on biological systems, including on person. However, there are few publications describing the mechanism of these influences on human. First of all it is necessary to point out that electromagnetic waves, the flow of particles in space and magnetic storms, acting on person human-all is connected with biophysical processes. So approach to influence of these factors on organism follows the processes of influence of these waves on bio system. Magnetic storms are phenomena continuously connected with solar activity. Investigation of cosmic space has intensified the practical importance of the problem of interaction with natural factors of external ambience. Much attention deserves the cosmic radiation, geomagnetic field, elements of climate and weathers. However the mechanism of bio tropic action of these factors is not enough studied. Beginning XXI century was already signified the successes in investigation of Mars. The Space shuttles 'Spirit' and 'Opportunity' successfully have carried out some work on examining and finding of water on Mars. A flight of person to Mars is being considered. One of the important mechanisms of influence on human organism is, in our opinion, the rising of the resonance at coincidence of frequencies and their more important factor is a phenomena of electromagnetic induction and forming the radicals in the organism. (author)

  4. A dynamic system to forecast ionospheric storm disturbances based on solar wind conditions

    Directory of Open Access Journals (Sweden)

    L. R. Cander

    2005-06-01

    Full Text Available For the reliable performance of technologically advanced radio communications systems under geomagnetically disturbed conditions, the forecast and modelling of the ionospheric response during storms is a high priority. The ionospheric storm forecasting models that are currently in operation have shown a high degree of reliability during quiet conditions, but they have proved inadequate during storm events. To improve their prediction accuracy, we have to take advantage of the deeper understanding in ionospheric storm dynamics that is currently available, indicating a correlation between the Interplanetary Magnetic Field (IMF disturbances and the qualitative signature of ionospheric storm disturbances at middle latitude stations. In this paper we analyse observations of the foF2 critical frequency parameter from one mid-latitude European ionospheric station (Chilton in conjunction with observations of IMF parameters (total magnitude, Bt and Bz-IMF component from the ACE spacecraft mission for eight storm events. The determination of the time delay in the ionospheric response to the interplanetary medium disturbances leads to significant results concerning the forecast of the ionospheric storms onset and their development during the first 24 h. In this way the real-time ACE observations of the solar wind parameters may be used in the development of a real-time dynamic ionospheric storm model with adequate accuracy.

  5. NARX neural network Prediction of SYMH and ASYH indices for geomagnetic storms of solar cycle 24 including recent St. Patrick's day, 2015 storm

    Science.gov (United States)

    Bhaskar, A. T.; Vichare, G.

    2017-12-01

    Here, an attempt is made to develop a prediction model for SYMH and ASYH geomagnetic indices using Artificial Neural Network (ANN). SYMH and ASYH indices represent longitudinal symmetric and asymmetric component of the ring current. The ring current state depends on its past conditions therefore, it is necessary to consider its history for prediction. To account this effect Nonlinear Autoregressive Network with eXogenous inputs (NARX) is implemented. This network considers input history of 30 minutes and output feedback of 120 minutes. Solar wind parameters mainly velocity, density and interplanetary magnetic field are used as inputs. SYMH and ASYH indices during geomagnetic storms of 1998-2013, having minimum SYMH training two independent networks. We present the prediction of SYMH and ASYH indices during 9 geomagnetic storms of solar cycle 24 including the recent largest storm occurred on St. Patrick's day, 2015. The present prediction model reproduces the entire time profile of SYMH and ASYH indices along with small variations of 10-30 minutes to good extent within noise level, indicating significant contribution of interplanetary sources and past state of the magnetosphere. However, during the main phase of major storms, residuals (observed-modeled) are found to be large, suggesting influence of internal factors such as magnetospheric processes.

  6. The structure of the big magnetic storms

    International Nuclear Information System (INIS)

    Mihajlivich, J. Spomenko; Chop, Rudi; Palangio, Paolo

    2010-01-01

    The records of geomagnetic activity during Solar Cycles 22 and 23 (which occurred from 1986 to 2006) indicate several extremely intensive A-class geomagnetic storms. These were storms classified in the category of the Big Magnetic Storms. In a year of maximum solar activity during Solar Cycle 23, or more precisely, during a phase designated as a post-maximum phase in solar activity (PPM - Phase Post maximum), near the autumn equinox, on 29, October 2003, an extremely strong and intensive magnetic storm was recorded. In the first half of November 2004 (7, November 2004) an intensive magnetic storm was recorded (the Class Big Magnetic Storm). The level of geomagnetic field variations which were recorded for the selected Big Magnetic Storms, was ΔD st=350 nT. For the Big Magnetic Storms the indicated three-hour interval indices geomagnetic activity was Kp = 9. This study presents the spectral composition of the Di - variations which were recorded during magnetic storms in October 2003 and November 2004. (Author)

  7. Predicting the occurrence of super-storms

    Directory of Open Access Journals (Sweden)

    N. Srivastava

    2005-11-01

    Full Text Available A comparative study of five super-storms (Dst<-300 nT of the current solar cycle after the launch of SoHO, to identify solar and interplanetary variables that influence the magnitude of resulting geomagnetic storms, is described. Amongst solar variables, the initial speed of a CME is considered the most reliable predictor of the strength of the associated geomagnetic storm because fast mass ejections are responsible for building up the ram pressure at the Earth's magnetosphere. However, although most of the super-storms studied were associated with high speed CMEs, the Dst index of the resulting geomagnetic storms varied between -300 to -472 nT. The most intense storm of 20 November 2003, (Dst ~ -472 nT had its source in a comparatively smaller active region and was associated with a relatively weaker, M-class flare while all other super-storms had their origins in large active regions and were associated with strong X-class flares. However, this superstorm did not show any associated extraordinary solar and interplanetary characteristics. The study also reveals the challenge in the reliable prediction of the magnitude of a geomagnetic storm from solar and interplanetary variables.

  8. Extreme Geomagnetic Storms – 1868–2010

    DEFF Research Database (Denmark)

    Vennerstrøm, Susanne; Lefèvre, L.; Dumbović, M.

    2016-01-01

    presents our investigation of the corresponding solar eventsand their characteristics. The storms were selected based on their intensity in the aa index,which constitutes the longest existing continuous series of geomagnetic activity. They areanalyzed statistically in the context of more well...... occurring in May 1921 and the Quebec storm from March 1989. We identifykey characteristics of the storms by combining several different available data sources, listsof storm sudden commencements (SSCs) signifying occurrence of interplanetary shocks,solar wind in-situ measurements, neutron monitor data...... %), Forbushdecreases (100 %), and energetic solar proton events (70 %). A quantitative comparison ofthese associations relative to less intense storms is also presented. Most notably, we findthat most often the extreme storms are characterized by a complexity that is associated with multiple, often interacting, solar...

  9. NASA seeks to revive lost probe that traced solar storms

    Science.gov (United States)

    Voosen, Paul

    2018-02-01

    NASA's Imager for Magnetopause-to-Aurora Global Exploration (IMAGE), a satellite that failed in 2005, was recently discovered to be reactivated by an amateur astronomer. Until its demise, IMAGE provided unparalleled views of solar storms crashing into Earth's magnetosphere, a capability that has not been replaced since. The amateur astronomer was on the search for Zuma, a classified U.S. satellite that's believed to have failed after launch. He instead discovered IMAGE, broadcasting again, likely thanks to a reboot that occurred after its batteries drained during a past solar eclipse. NASA scientists are now working to communicate with the satellite in the hopes of reviving its six scientific instruments.

  10. Great magnetic storms

    International Nuclear Information System (INIS)

    Tsurutani, B.T.; Yen Te Lee; Tang, F.; Gonzalez, W.D.

    1992-01-01

    The five largest magnetic storms that occurred between 1971 and 1986 are studied to determine their solar and interplanetary causes. All of the events are found to be associated with high speed solar wind streams led by collisionless shocks. The high speed streams are clearly related to identifiable solar flares. It is found that (1) it is the extreme values of the southward interplanetary magnetic fields rather than solar wind speeds that are the primary causes of great magnetic storms, (2) shocked and draped sheath fields preceding the driver gas (magnetic cloud) are at least as effective in causing the onset of great magnetic storms (3 of 5 events ) as the strong fields within the driver gas itself, and (3) precursor southward fields ahead of the high speed streams allow the shock compression mechanism (item 2) to be particularly geoeffective

  11. 3DCORE: Forward modeling of solar storm magnetic flux ropes for space weather prediction

    Science.gov (United States)

    Möstl, C.; Amerstorfer, T.; Palmerio, E.; Isavnin, A.; Farrugia, C. J.; Lowder, C.; Winslow, R. M.; Donnerer, J. M.; Kilpua, E. K. J.; Boakes, P. D.

    2018-05-01

    3DCORE forward models solar storm magnetic flux ropes called 3-Dimensional Coronal Rope Ejection (3DCORE). The code is able to produce synthetic in situ observations of the magnetic cores of solar coronal mass ejections sweeping over planets and spacecraft. Near Earth, these data are taken currently by the Wind, ACE and DSCOVR spacecraft. Other suitable spacecraft making these kind of observations carrying magnetometers in the solar wind were MESSENGER, Venus Express, MAVEN, and even Helios.

  12. Assessing the Performance of GPS Precise Point Positioning Under Different Geomagnetic Storm Conditions during Solar Cycle 24

    Directory of Open Access Journals (Sweden)

    Xiaomin Luo

    2018-06-01

    Full Text Available The geomagnetic storm, which is an abnormal space weather phenomenon, can sometimes severely affect GPS signal propagation, thereby impacting the performance of GPS precise point positioning (PPP. However, the investigation of GPS PPP accuracy over the global scale under different geomagnetic storm conditions is very limited. This paper for the first time presents the performance of GPS dual-frequency (DF and single-frequency (SF PPP under moderate, intense, and super storms conditions during solar cycle 24 using a large data set collected from about 500 international GNSS services (IGS stations. The global root mean square (RMS maps of GPS PPP results show that stations with degraded performance are mainly distributed at high-latitude, and the degradation level generally depends on the storm intensity. The three-dimensional (3D RMS of GPS DF PPP for high-latitude during moderate, intense, and super storms are 0.393 m, 0.680 m and 1.051 m, respectively, with respect to only 0.163 m on quiet day. RMS errors of mid- and low-latitudes show less dependence on the storm intensities, with values less than 0.320 m, compared to 0.153 m on quiet day. Compared with DF PPP, the performance of GPS SF PPP is inferior regardless of quiet or disturbed conditions. The degraded performance of GPS positioning during geomagnetic storms is attributed to the increased ionospheric disturbances, which have been confirmed by our global rate of TEC index (ROTI maps. Ionospheric disturbances not only lead to the deteriorated ionospheric correction but also to the frequent cycle-slip occurrence. Statistical results show that, compared with that on quiet day, the increased cycle-slip occurrence are 13.04%, 56.52%, and 69.57% under moderate, intense, and super storms conditions, respectively.

  13. Substorms during different storm phases

    Directory of Open Access Journals (Sweden)

    N. Partamies

    2011-11-01

    Full Text Available After the deep solar minimum at the end of the solar cycle 23, a small magnetic storm occurred on 20–26 January 2010. The Dst (disturbance storm time index reached the minimum of −38 nT on 20 January and the prolonged recovery that followed the main phase that lasted for about 6 days. In this study, we concentrate on three substorms that took place (1 just prior to the storm, (2 during the main phase of the storm, and (3 at the end of the recovery of the storm. We analyse the solar wind conditions from the solar wind monitoring spacecraft, the duration and intensity of the substorm events as well as the behaviour of the electrojet currents from the ground magnetometer measurements. We compare the precipitation characteristics of the three substorms. The results show that the F-region electron density enhancements and dominant green and red auroral emission of the substorm activity during the storm recovery resembles average isolated substorm precipitation. However, the energy dissipated, even at the very end of a prolonged storm recovery, is very large compared to the typical energy content of isolated substorms. In the case studied here, the dissipation of the excess energy is observed over a 3-h long period of several consecutive substorm intensifications. Our findings suggest that the substorm energy dissipation varies between the storm phases.

  14. Space storms as natural hazards

    Directory of Open Access Journals (Sweden)

    L. I. Dorman

    2008-04-01

    Full Text Available Eruptive activity of the Sun produces a chain of extreme geophysical events: high-speed solar wind, magnetic field disturbances in the interplanetary space and in the geomagnetic field and also intense fluxes of energetic particles. Space storms can potentially destroy spacecrafts, adversely affect astronauts and airline crew and human health on the Earth, lead to pipeline breaking, melt electricity transformers, and discontinue transmission. In this paper we deal with two consequences of space storms: (i rise in failures in the operation of railway devices and (ii rise in myocardial infarction and stroke incidences.

  15. The Future of Geomagnetic Storm Predictions: Implications from Recent Solar and Interplanetary Observations

    Science.gov (United States)

    Tsurutani, B. T.; Gonzalez, W. D.

    1995-01-01

    Within the last 7-8 years, there has been a substantial growth in out knowledge of the solar and interplanetary causes of geomagnetic storms at Earth. This review article will not attempt to cover all of the work done during this period. This can be found elsewhere. Our emphasis here will be on recent efforts that expose important, presently unanswered questions that must be addressed and solved before true predictability of storms can be possible. Hopefully, this article will encourage some readers to join this effort and perhaps make major contributions to the field.

  16. Effect of geomagnetic storms on VHF scintillations observed at low latitude

    Science.gov (United States)

    Singh, S. B.; Patel, Kalpana; Singh, A. K.

    2018-06-01

    A geomagnetic storm affects the dynamics and composition of the ionosphere and also offers an excellent opportunity to study the plasma dynamics. In the present study, we have used the VHF scintillations data recorded at low latitude Indian station Varanasi (Geomag. latitude = 14^{°}55^' }N, long. = 154^{°}E) which is radiated at 250 MHz from geostationary satellite UFO-02 during the period 2011-2012 to investigate the effects of geomagnetic storms on VHF scintillation. Various geomagnetic and solar indices such as Dst index, Kp index, IMF Bz and solar wind velocity (Vx) are used to describe the geomagnetic field variation observed during geomagnetic storm periods. These indices are very helpful to find out the proper investigation and possible interrelation between geomagnetic storms and observed VHF scintillation. The pre-midnight scintillation is sometimes observed when the main phase of geomagnetic storm corresponds to the pre-midnight period. It is observed that for geomagnetic storms for which the recovery phase starts post-midnight, the probability of occurrence of irregularities is enhanced during this time and extends to early morning hours.

  17. Interplanetary radio storms. II - Emission levels and solar wind speed in the range 0.05-0.8 AU

    Science.gov (United States)

    Bougeret, J.-L.; Fainberg, J.; Stone, R. G.

    1984-01-01

    Storms of interplanetary type III radio bursts (IP storms) are commonly observed in the interplanetary medium by the ISEE-3 radio instrument. This instrument has the capability of accurately determining the arrival direction of the radio emission. At each observing frequency, the storm radio sources are tracked as they cross the line-of-sight to the sun. Using a simple model, the emission levels are determined at a number of radio frequencies for four separate storms. The IP storm radiation is found to occur in regions of enhanced density at levels of 0.05 to 0.8 AU. The density in these enhancements falls off faster than R(-2). The solar wind speed in the storm region is also measured. The analysis is consistent with steady conditions in the storm region during a few days around the III storm burst radio emission at the harmonic of the local plasma frequency.

  18. Energetics of small electron acceleration episodes in the solar corona from radio noise storm observations

    Science.gov (United States)

    James, Tomin; Subramanian, Prasad

    2018-05-01

    Observations of radio noise storms can act as sensitive probes of nonthermal electrons produced in small acceleration events in the solar corona. We use data from noise storm episodes observed jointly by the Giant Metrewave Radio Telescope (GMRT) and the Nancay Radioheliograph (NRH) to study characteristics of the nonthermal electrons involved in the emission. We find that the electrons carry 1021 to 1024 erg/s, and that the energy contained in the electrons producing a representative noise storm burst ranges from 1020 to 1023 ergs. These results are a direct probe of the energetics involved in ubiquitous, small-scale electron acceleration episodes in the corona, and could be relevant to a nanoflare-like scenario for coronal heating.

  19. Changes in the High-Latitude Topside Ionospheric Vertical Electron-Density Profiles in Response to Solar-Wind Perturbations During Large Magnetic Storms

    Science.gov (United States)

    Benson, Robert F.; Fainberg, Joseph; Osherovich, Vladimir; Truhlik, Vladimir; Wang, Yongli; Arbacher, Becca

    2011-01-01

    The latest results from an investigation to establish links between solar-wind and topside-ionospheric parameters will be presented including a case where high-latitude topside electron-density Ne(h) profiles indicated dramatic rapid changes in the scale height during the main phase of a large magnetic storm (Dst wind data obtained from the NASA OMNIWeb database indicated that the magnetic storm was due to a magnetic cloud. This event is one of several large magnetic storms being investigated during the interval from 1965 to 1984 when both solar-wind and digital topside ionograms, from either Alouette-2, ISIS-1, or ISIS-2, are potentially available.

  20. Non-storm irregular variation of the Dst index

    Directory of Open Access Journals (Sweden)

    S. Nakano

    2012-01-01

    Full Text Available The Dst index has a long-term variation that is not associated with magnetic storms. We estimated the long-term non-storm component of the Dst variation by removing the short-term variation related to magnetic storms. The results indicate that the variation of the non-storm component includes not only a seasonal variation but also an irregular variation. The irregular long-term variation is likely to be due to an anti-correlation with the long-term variation of solar-wind activity. In particular, a clear anti-correlation is observed between the non-storm component of Dst and the long-term variation of the solar-wind dynamic pressure. This means that in the long term, the Dst index tends to increase when the solar-wind dynamic pressure decreases. We interpret this anti-correlation as an indication that the long-term non-storm variation of Dst is influenced by the tail current variation. The long-term variation of the solar-wind dynamic pressure controls the plasma sheet thermal pressure, and the change of the plasma sheet thermal pressure would cause the non-storm tail current variation, resulting in the non-storm variation of Dst.

  1. IRI STORM validation over Europe

    Science.gov (United States)

    Haralambous, Haris; Vryonides, Photos; Demetrescu, Crişan; Dobrică, Venera; Maris, Georgeta; Ionescu, Diana

    2014-05-01

    The International Reference Ionosphere (IRI) model includes an empirical Storm-Time Ionospheric Correction Model (STORM) extension to account for storm-time changes of the F layer peak electron density (NmF2) during increased geomagnetic activity. This model extension is driven by past history values of the geomagnetic index ap (The magnetic index applied is the integral of ap over the previous 33 hours with a weighting function deduced from physically based modeling) and it adjusts the quiet-time F layer peak electron density (NmF2) to account for storm-time changes in the ionosphere. In this investigation manually scaled hourly values of NmF2 measured during the main and recovery phases of selected storms for the maximum solar activity period of the current solar cycle are compared with the predicted IRI-2012 NmF2 over European ionospheric stations using the STORM model option. Based on the comparison a subsequent performance evaluation of the STORM option during this period is quantified.

  2. Mathematical modeling of the moderate storm on 28 February 2008

    Science.gov (United States)

    Eroglu, Emre

    2018-04-01

    The sun is an active star with plasma-filled prominences. The sudden ejection of the solar plasma creates storms in the form of bursting or spraying. A magnetospheric storm is a typical phenomenon that lasts 1-3 days and involves all magnetosphere from the earth's ionosphere to the magnetotail. The storms are known by different categorical names such as weak, moderate, strong, intense. One of these is the moderate geomagnetic storm on February 28, 2008, which occurred in the 24th solar cycle. The reason for discussing this storm is that it is the first moderate storm in the 24th solar cycle. In this study, we investigate the storm and entered the 24th solar cycle. The correlation among the parametres has been investigated via statistics. The solar wind parameters and the zonal geomagnetic indices have been analyzed separately and then the interaction with each other has been exhibited. The author has concluded the work with two new nonlinear mathematical models. These explain the storm with 79.1% and 87.5% accuracy.

  3. Interplanetary radio storms. 2: Emission levels and solar wind speed in the range 0.05-0.8 AU

    Science.gov (United States)

    Bougeret, J. L.; Fainberg, J.; Stone, R. G.

    1982-01-01

    Storms of interplanetary type III radio bursts (IP storms) are commonly observed in the interplanetry medium by the ISEE-3 radio instrument. This instrument has the capability of accurately determining the arrival direction of the radio emission. At each observing frequency, the storm radio sources are tracked as they cross the line-of-sight to the Sun. Usng a simple model, the emission levels are determined at a number of radio frequencies for four separate storms. The IP storm radiation is found to occur in regions of enhanced density at levels of 0.05 to 0.8 AU. The density in these enhancements falls off faster than R(-2). The solar wind speed in the storm region is also measured. The analysis is consistent with steady conditions in the storm region during a few days around the central meridian passage of the storm. The comparison with average in situ density measurements compiled from the HELIOS 1-2 observations favors type III storm burst radio emission at the harmonic of the local plasma frequency.

  4. Ionospheric storms at geophysically-equivalent sites – Part 1: Storm-time patterns for sub-auroral ionospheres

    Directory of Open Access Journals (Sweden)

    M. Mendillo

    2009-04-01

    Full Text Available The systematic study of ionospheric storms has been conducted primarily with groundbased data from the Northern Hemisphere. Significant progress has been made in defining typical morphology patterns at all latitudes; mechanisms have been identified and tested via modeling. At higher mid-latitudes (sites that are typically sub-auroral during non-storm conditions, the processes that change significantly during storms can be of comparable magnitudes, but with different time constants. These include ionospheric plasma dynamics from the penetration of magnetospheric electric fields, enhancements to thermospheric winds due to auroral and Joule heating inputs, disturbance dynamo electrodynamics driven by such winds, and thermospheric composition changes due to the changed circulation patterns. The ~12° tilt of the geomagnetic field axis causes significant longitude effects in all of these processes in the Northern Hemisphere. A complementary series of longitude effects would be expected to occur in the Southern Hemisphere. In this paper we begin a series of studies to investigate the longitudinal-hemispheric similarities and differences in the response of the ionosphere's peak electron density to geomagnetic storms. The ionosonde stations at Wallops Island (VA and Hobart (Tasmania have comparable geographic and geomagnetic latitudes for sub-auroral locations, are situated at longitudes close to that of the dipole tilt, and thus serve as our candidate station-pair choice for studies of ionospheric storms at geophysically-comparable locations. They have an excellent record of observations of the ionospheric penetration frequency (foF2 spanning several solar cycles, and thus are suitable for long-term studies. During solar cycle #20 (1964–1976, 206 geomagnetic storms occurred that had Ap≥30 or Kp≥5 for at least one day of the storm. Our analysis of average storm-time perturbations (percent deviations from the monthly means showed a remarkable

  5. Classification and quantification of solar wind driver gases leading to intense geomagnetic storms

    Science.gov (United States)

    Adekoya, B. J.; Chukwuma, V. U.

    2018-01-01

    Classification and quantification of the interplanetary structures causing intense geomagnetic storms (Dst ≤ -100 nT) that occurred during 1997-2016 are studied. The subject of this consists of solar wind parameters of seventy-three intense storms that are associated with the southward interplanetary magnetic field. About 30.14% of the storms were driven by a combination of the sheath and ejecta (S + E), magnetic clouds (MC) and sheath field (S) are 26% each, 10.96% by combined sheath and MCs (S + C), while 5.48% of the storms were driven by ejecta (E) alone. Therefore, we want to aver that for storms driven by: (1) S + E. The Bz is high (≥10 nT), high density (ρ) (>10 N/cm3), high plasma beta (β) (>0.8), and unspecified (i.e. high or low) structure of the plasma temperature (T) and the flow speed (V); (2) MC. The Bz is ≥10 nT, low temperature (T ≤ 400,000 K), low ρ (≤10 N/cm3), high V (≥450 km), and low β (≤0.8); (3) The structures of S + C are similar to that of MC except that the V is low (V ≤ 450 km); (4) S. The Bz is high, low T, high ρ, unspecified V, and low β; and (5) E. Is when the structures are directly opposite of the one driven by MCs except for high V. Although, westward ring current indicates intense storms, but the large intensity of geomagnetic storms is determined by the intense nature of the electric field strength and the Bz. Therefore, great storms (i.e. Dst ≤ -200 nT) are manifestation of high electric field strength (≥13 mV/m).

  6. A comparative study of night-time enhancement of TEC at a low latitude station on storm and quiet nights including the local time, seasonal and solar activity dependence

    Directory of Open Access Journals (Sweden)

    K. Unnikrishnan

    Full Text Available The main characteristics of night-time enhancements in TEC during magnetic storms are compared with those during quiet nights for different seasons and solar activity conditions at Palehua, a low latitude station during the period 1980–1989. We find that the mean amplitude has both a seasonal and solar activity dependence: in winter, the values are higher for weak storms as compared to those during quiet nights and increase with an increase in solar activity. In summer, the mean amplitude values during weak storms and quiet nights are almost equal. But during equinox, the mean amplitude values for quiet nights are greater than those during weak storms. The mean half-amplitude duration is higher during weak storms as compared to that during quiet nights in summer. However, during winter and equinox, the durations are almost equal for both quiet and weak storm nights. For the mean half-amplitude duration, the quiet night values for all the seasons and equinoctial weak storm values increase with an increase in solar activity. The occurrence frequency (in percent of TEC enhancement during weak storms is greater than during quiet nights for all seasons. The mean amplitude, the mean half-amplitude duration and the occurrence frequency (in percent of TEC enhancement values are higher during major storms as compared to those during quiet nights. The above parameters have their highest values during pre-midnight hours. From the data analysed, this behaviour is true in the case of major storms also.

    Key words. Ionosphere (ionospheric disturbances; plasma convection Magnetospheric physics (storms and substorms

  7. Study of the mid-latitude ionospheric response to geomagnetic storms in the European region

    Science.gov (United States)

    Berényi, Kitti Alexandra; Barta, Veronika; Kis, Arpad

    2016-07-01

    Geomagnetic storms affect the ionospheric regions of the terrestrial upper atmosphere through different physical and atmospheric processes. The phenomena that can be regarded as a result of these processes, generally is named as "ionospheric storm". The processes depend on altitude, segment of the day, the geomagnetic latitude and longitude, strength of solar activity and the type of the geomagnetic storm. We examine the data of ground-based radio wave ionosphere sounding measurements of European ionospheric stations (mainly the data of Nagycenk Geophysical Observatory) in order to determine how and to what extent a geomagnetic disturbance of a certain strength affects the mid-latitude ionospheric regions in winter and in summer. For our analysis we used disturbed time periods between November 2012 and June 2015. Our results show significant changing of the ionospheric F2 layer parameters on strongly disturbed days compared to quiet ones. We show that the critical frequencies (foF2) increase compared to their quiet day value when the ionospheric storm was positive. On the other hand, the critical frequencies become lower, when the storm was negative. In our analysis we determined the magnitude of these changes on the chosen days. For a more complete analysis we compare also the evolution of the F2 layer parameters of the European ionosonde stations on a North-South geographic longitude during a full storm duration. The results present the evolution of an ionospheric storm over a geographic meridian. Furthermore, we compared the two type of geomagnetic storms, namely the CME caused geomagnetic storm - the so-called Sudden impulse (Si) storms- and the HSS (High Speed Solar Wind Streams) caused geomagnetic storms -the so-called Gradual storms (Gs)- impact on the ionospheric F2-layer (foF2 parameter). The results show a significant difference between the effect of Si and of the Gs storms on the ionospheric F2-layer.

  8. Spectropolarimetric Observations of Solar Noise Storms at Low Frequencies

    Science.gov (United States)

    Mugundhan, V.; Ramesh, R.; Kathiravan, C.; Gireesh, G. V. S.; Hegde, Aathira

    2018-03-01

    A new high-resolution radio spectropolarimeter instrument operating in the frequency range of 15 - 85 MHz has recently been commissioned at the Radio Astronomy Field Station of the Indian Institute of Astrophysics at Gauribidanur, 100 km north of Bangalore, India. We describe the design and construction of this instrument. We present observations of a solar radio noise storm associated with Active Region (AR) 12567 in the frequency range of {≈} 15 - 85 MHz during 18 and 19 July 2016, observed using this instrument in the meridian-transit mode. This is the first report that we are aware of in which both the burst and continuum properties are derived simultaneously. Spectral indices and degree of polarization of both the continuum radiation and bursts are estimated. It is found that i) Type I storm bursts have a spectral index of {≈} {+}3.5, ii) the spectral index of the background continuum is ≈+2.9, iii) the transition frequency between Type I and Type III storms occurs at ≈55 MHz, iv) Type III bursts have an average spectral index of ≈-2.7, v) the spectral index of the Type III continuum is ≈-1.6, and vi) the degree of circular polarization of all Type I (Type III) bursts is ≈90% (30%). The results obtained here indicate that the continuum emission is due to bursts occurring in rapid succession. We find that the derived parameters for Type I bursts are consistent with suprathermal electron acceleration theory and those of Type III favor fundamental plasma emission.

  9. A superposed epoch analysis of geomagnetic storms

    Directory of Open Access Journals (Sweden)

    J. R. Taylor

    1994-06-01

    Full Text Available A superposed epoch analysis of geomagnetic storms has been undertaken. The storms are categorised via their intensity (as defined by the Dst index. Storms have also been classified here as either storm sudden commencements (SSCs or storm gradual commencements (SGCs, that is all storms which did not begin with a sudden commencement. The prevailing solar wind conditions defined by the parameters solar wind speed (vsw, density (ρsw and pressure (Psw and the total field and the components of the interplanetary magnetic field (IMF during the storms in each category have been investigated by a superposed epoch analysis. The southward component of the IMF, appears to be the controlling parameter for the generation of small SGCs (-100 nT< minimum Dst ≤ -50 nT for ≥ 4 h, but for SSCs of the same intensity solar wind pressure is dominant. However, for large SSCs (minimum Dst ≤ -100 nT for ≥ 4 h the solar wind speed is the controlling parameter. It is also demonstrated that for larger storms magnetic activity is not solely driven by the accumulation of substorm activity, but substantial energy is directly input via the dayside. Furthermore, there is evidence that SSCs are caused by the passage of a coronal mass ejection, whereas SGCs result from the passage of a high speed/ slow speed coronal stream interface. Storms are also grouped by the sign of Bz during the first hour epoch after the onset. The sign of Bz at t = +1 h is the dominant sign of the Bz for ~24 h before the onset. The total energy released during storms for which Bz was initially positive is, however, of the same order as for storms where Bz was initially negative.

  10. The effect of magnetic storm on the bottomside profile parameters B0 and

    International Nuclear Information System (INIS)

    Adeniyi, J.O.; Radicella, S.M.

    2001-01-01

    We have used data from an equatorial station for the investigation of magnetic storm effects on B0 and B1. Three storm events, which occurred in January, April and October of a low solar activity year (1995), were used for the study. B0 is the parameter that is mostly affected and the effect is concentrated on the daytime period (0700-1700LT). (author)

  11. Flow of Energy through the Inner Magnetosphere during the March 17, 2015 solar storm as observed by the Van Allen Probes Radiation Belt Storm Probes Ion Composition Experiment (RBSPICE)

    Science.gov (United States)

    Manweiler, J. W.; Madanian, H.; Gerrard, A. J.; Patterson, J. D.; Mitchell, D. G.; Lanzerotti, L. J.

    2017-12-01

    On March 17, 2015, a large solar storm impacted the Earth's magnetosphere with a maximum negative Dst of -232 nT. We report on the temporal and spatial evolution of the proton energetic particle distributions in phase space during this storm, as measured by the Radiation Belt Storm Probes Ion Composition Experiment (RBSPICE) instrument on board each of the Van Allen Probes. We characterize the distribution prior to onset of the storm to provide a definition of quiet time conditions. We then show how the distribution evolves during the storm noting key changes of the distribution as a function of L and MLT and showing how the pitch angle distributions change throughout the storm. These observations displayed a number of interesting features of the storm including high beta plasma conditions and multiple injections of protons into the inner magnetosphere. We present the radial changes of the distribution at storm onset and following the evolution of the distribution during storm recovery. We compare observations of the East/West asymmetry in the proton distribution before versus after onset using both Van Allen Probes A and B spacecraft observations. Finally, we note interesting changes in the distribution showing an anomalous dropout in mid-energies of the distribution and observe an outward radial propagation of this dropout during recovery.

  12. Energetic evaluation of the largest geomagnetic storms of solar cycle 24 on March 17, 2015 and September 8, 2017 during solar maximum and minimum, respectively

    International Nuclear Information System (INIS)

    Tomova, Dimitrinka; Velinov, Peter; Tassev, Yordan; Tomova, Dimitrinka

    2018-01-01

    Some of the most powerful Earth’s directed coronal mass ejections (CMEs) from the current 24 solar cycle have been investigated. These are CMEs on March 15, 2015 and on September 4 and 6, 2017. As a result of these impacts of Sun on Earth, the highest intensity of the geomagnetic storms for the 24th solar cycle is observed. These G4 – Severe geomagnetic storms are in the periods March 17÷19, 2015 and September 7÷10, 2017. We use the solar wind parameters (velocity V, density or concentration N , temperature T p and intensity of the magnetic field B) from measurements by WIND, ACE and SOHO space crafts in the Lagrange equilibrium point L1 between Sun and Earth. We make calculations for the kinetic (dynamic) energy density E k , thermal energy density E t and magnetic energy density E m during the investigated periods May 10÷24, 2015 and September 2÷16, 2017. Both the energy densities for the individual events and the cumulative energy for each of them are evaluated. The quantitative analysis shows that not always the size of the geomagnetic reaction is commensurate with the density of the energy flux reaching the magnetosphere. In both studied periods, the energy densities have different behaviour over time. But for both periods, we can talk about the prognostic effect – with varying degrees of increase of the dynamic and thermal energies. Such an effect is not observed in the density of magnetic energy. An inverse relationship between the magnitude of the density of energies and the effect of Forbush decrease of the galactic cosmic rays is established. Key words: solar activity, flares, coronal mass ejection (CME), G4 –Severe geomagnetic storms, energy density of the solar wind, space weather

  13. Thermospheric response observed over Fritz peak, Colorado, during two large geomagnetic storms near solar cycle maximum

    International Nuclear Information System (INIS)

    Hernandez, G.; Roble, R.G.; Ridley, E.C.; Allen, J.H.

    1982-01-01

    Nightime thermospheric winds and temperatures have been measured over Fritz Peak Observatory, Colorado (39.9 0 N, 105.5 0 W), with a high resolution Fabry-Perot spectrometer. The winds and temperatures are obtained from the Doppler shifts and line profiles of the (O 1) 15,867K (630 nm) line emission. Measurements made during two large geomagnetic storm periods near solar cycle maximum reveal a thermospheric response to the heat and momentum sources associated with these storms that is more complex than the ones measured near solar cycle minimum. In the earlier measurements made during solar cycle minimum, the winds to the north of Fritz Peak Observatory had an enhanced equatorward component and the winds to the south were also equatorward, usually with smaller velocities. The winds measured to the east and west of the observatory both had an enhanced westward wind component. For the two large storms near the present solar cycle maximum period converging winds are observed in each of the cardinal directions from Fritz Peak Observatory. These converging winds with speeds of hundreds of meters per second last for several hours. The measured neutral gas temperature in each of the directions also increases several hundred degrees Kelvin. Numerical experiments done with the NCAR thermospheric general circulation model (TGCM) suggest that the winds to the east and north of the station are driven by high-latitude heating and enhanced westward ion drag associated with magnetospheric convection. The cause of the enhanced poleward and eastward winds measured to the south and west of Fritz Peak Observatory, respectively, is not known. During geomagnetic quiet conditions the circulation is typically from the soutwest toward the northeast in the evening hours

  14. The Role of Ionospheric Outflow Preconditioning in Determining Storm Geoeffectiveness

    Science.gov (United States)

    Welling, D. T.; Liemohn, M. W.; Ridley, A. J.

    2012-12-01

    It is now well accepted that ionospheric outflow plays an important role in the development of the plasma sheet and ring current during geomagnetic storms. Furthermore, even during quiet times, ionospheric plasma populates the magnetospheric lobes, producing a reservoir of hydrogen and oxygen ions. When the Interplanetary Magnetic Field (IMF) turns southward, this reservoir is connected to the plasma sheet and ring current through magnetospheric convection. Hence, the conditions of the ionosphere and magnetospheric lobes leading up to magnetospheric storm onset have important implications for storm development. Despite this, there has been little research on this preconditioning; most global simulations begin just before storm onset, neglecting preconditioning altogether. This work explores the role of preconditioning in determining the geoeffectiveness of storms using a coupled global model system. A model of ionospheric outflow (the Polar Wind Outflow Model, PWOM) is two-way coupled to a global magnetohydrodynamic model (the Block-Adaptive Tree Solar wind Roe-type Upwind Scheme, BATS-R-US), which in turn drives a ring current model (the Ring current Atmosphere interactions Model, RAM). This unique setup is used to simulate an idealized storm. The model is started at many different times, from 1 hour before storm onset to 12 hours before. The effects of storm preconditioning are examined by investigating the total ionospheric plasma content in the lobes just before onset, the total ionospheric contribution in the ring current just after onset, and the effects on Dst, magnetic elevation angle at geosynchronous, and total ring current energy density. This experiment is repeated for different solar activity levels as set by F10.7 flux. Finally, a synthetic double-dip storm is constructed to see how two closely spaced storms affect each other by changing the preconditioning environment. It is found that preconditioning of the magnetospheric lobes via ionospheric

  15. Storm Impact and Depression Among Older Adults Living in Hurricane Sandy-Affected Areas.

    Science.gov (United States)

    Sirey, Jo Anne; Berman, Jacquelin; Halkett, Ashley; Giunta, Nancy; Kerrigan, Janice; Raeifar, Elmira; Artis, Amanda; Banerjee, Samprit; Raue, Patrick J

    2017-02-01

    Research on the impact of natural disasters on the mental health of older adults finds both vulnerabilities and resilience. We report on the rates of clinically significant depression among older adults (aged ≥60 years) living in areas affected by Hurricane Sandy in 2012 and the factors associated with mental health need. The Sandy Mobilization, Assessment, Referral and Treatment for Mental Health (SMART-MH) program integrates community outreach and needs assessments to identify older adults with mental health and aging service needs. Older adults with significant anxiety or depressive symptoms were offered short-term psychotherapy. Social service referrals were made directly to community agencies. All SMART-MH activities were offered in Spanish, Russian, Mandarin/Cantonese, and English. Across the full sample, 14% of participants screened positive for depression. Hurricane Sandy stressors predicted increased odds of depression, including storm injury, post-storm crime, and the total count of stressors. Outcomes varied significantly by age group, such that all Sandy-related variables remained significant for younger-old adults (aged 60-74 years), whereas only the loss of access to medical care was significant for older-old adults (aged ≥75 years). Storm-affected communities show higher rates of depressive symptoms than seen in the general population, with storm stressors affecting mental health needs differentially by age group. (Disaster Med Public Health Preparedness. 2017;11:97-109).

  16. COMPARATIVE EVALUATION OF THE INFLUENCING EFFECTS OF GEOMAGNETIC SOLAR STORMS ON EARTHQUAKES IN ANATOLIAN PENINSULA

    Directory of Open Access Journals (Sweden)

    Yesugey Sadik Cengiz

    2009-07-01

    Full Text Available Earthquakes are tectonic events that take place within the fractures of the earth's crust, namely faults. Above certain scale, earthquakes can result in widespread fatalities and substantial financial loss. In addition to the movement of tectonic plates relative to each other, it is widely discussed that there are other external influences originate outside earth that can trigger earthquakes. These influences are called "triggering effects". The purpose of this article is to present a statistical view to elaborate if the solar geomagnetic storms trigger earthquakes.As a model, the research focuses on the Anatolian peninsula, presenting 41 years of historical data on magnetic storms and earthquakes collated from national and international resources. As a result of the comparative assessment of the data, it is concluded that the geomagnetic storms do not trigger earthquakes.

  17. From pre-storm activity to magnetic storms: a transition described in terms of fractal dynamics

    Directory of Open Access Journals (Sweden)

    G. Balasis

    2006-12-01

    Full Text Available We show that distinct changes in scaling parameters of the Dst index time series occur as an intense magnetic storm approaches, revealing a gradual reduction in complexity. The remarkable acceleration of energy release – manifested in the increase in susceptibility – couples to the transition from anti-persistent (negative feedback to persistent (positive feedback behavior and indicates that the occurence of an intense magnetic storm is imminent. The main driver of the Dst index, the VBSouth electric field component, does not reveal a similar transition to persistency prior to the storm. This indicates that while the magnetosphere is mostly driven by the solar wind the critical feature of persistency in the magnetosphere is the result of a combination of solar wind and internal magnetospheric activity rather than solar wind variations alone. Our results suggest that the development of an intense magnetic storm can be studied in terms of "intermittent criticality" that is of a more general character than the classical self-organized criticality phenomena, implying the predictability of the magnetosphere.

  18. Ring Current Response to Different Storm Drivers. Van Allen Probes and Cluster Observations.

    Science.gov (United States)

    Bingham, S.; Mouikis, C.; Kistler, L. M.; Spence, H. E.; Gkioulidou, M.; Claudepierre, S. G.; Farrugia, C. J.

    2015-12-01

    The ring current responds differently to the different solar and interplanetary storm drivers such as coronal mass injections, (CME's), co-rotating interaction regions (CIR's), high-speed streamers and other structures. The resulting changes in the ring current particle pressure change the global magnetic field, which affects the transport of the radiation belts. In order to determine the field changes during a storm it is necessary to understand the transport, sources and losses of the particles that contribute to the ring current. The source population of the storm time ring current is the night side plasma sheet. However, it is not clear how these convecting particles affect the storm time ring current pressure development. We use Van Allen Probes and Cluster observations together with the Volland-Stern and dipole magnetic field models to determine the contribution in the ring current pressure of the plasma sheet particles convecting from the night side that are on open drift paths, during the storm evolution. We compare storms that are related to different interplanetary drivers, CME and CIR, as observed at different local times.

  19. Dependence of regular background noise of VLF radiation and thunder-storm activity on solar wind proton density

    International Nuclear Information System (INIS)

    Sobolev, A.V.; Kozlov, V.I.

    1997-01-01

    Correlation of the intensity of slowly changing regular background noise within 9.7 kHz frequency in Yakutsk (L = 3) and of the solar wind density protons was determined. This result explains the reverse dependence of the intensity of the regular background noise on the solar activity, 27-day frequency, increase before and following geomagnetic storms, absence of relation with K p index of geomagnetic activity. Conclusion is made that growth of density of the solar wind protons results in increase of the regular background noise and thunderstorm activity

  20. Predicting geomagnetic storms from solar-wind data using time-delay neural networks

    Directory of Open Access Journals (Sweden)

    H. Gleisner

    1996-07-01

    Full Text Available We have used time-delay feed-forward neural networks to compute the geomagnetic-activity index Dst one hour ahead from a temporal sequence of solar-wind data. The input data include solar-wind density n, velocity V and the southward component Bz of the interplanetary magnetic field. Dst is not included in the input data. The networks implement an explicit functional relationship between the solar wind and the geomagnetic disturbance, including both direct and time-delayed non-linear relations. In this study we especially consider the influence of varying the temporal size of the input-data sequence. The networks are trained on data covering 6600 h, and tested on data covering 2100 h. It is found that the initial and main phases of geomagnetic storms are well predicted, almost independent of the length of the input-data sequence. However, to predict the recovery phase, we have to use up to 20 h of solar-wind input data. The recovery phase is mainly governed by the ring-current loss processes, and is very much dependent on the ring-current history, and thus also the solar-wind history. With due consideration of the time history when optimizing the networks, we can reproduce 84% of the Dst variance.

  1. Type 2 solar radio burst with the reverse frequency drift on the background of a noise storm

    International Nuclear Information System (INIS)

    Korolev, O.S.; Fomichev, V.V.; Chertok, I.M.

    1979-01-01

    Discussed are the main peculiarities of solar radio burst of the 2nd type recorded on November, 19, 1975 in 11sup(h)02sup(m)-11sup(h)06sup(m)UT in the 45-90 MHz range. The burst considered occurred at the background of the developed noise storm with continuum radiation chearacteristic of it and narrow band. Short-term burst of the first type. The burst band drift was accompanied by the successive cessation of noise storm radiation at frequencies of 50-70 MHz. This phenomenon is interpreted as the result of the interaction between the shock wave spreading in the direction of increasing electron density, and the source of noise storm in coronal plasma. Estimated is the shock wave rate and the paremeters of coronal plasma in the direction of its spreading. A mechanism of interaction between the shock wave and the noise storm source is studied. The observed cessation of noise storm generation is explained by violation of conditions of development of instabilities, in particular, with the isotropization of electrons in the radiation source

  2. Exceptional winter storms affecting Western Iberia and extremes: diagnosis, modelling and multi-model ensemble projection

    Science.gov (United States)

    Liberato, M. L. R.; Pinto, J. G.; Gil, V.; Ramos, A. M.; Trigo, R. M.

    2017-12-01

    Extratropical cyclones dominate autumn and winter weather over Western Europe and particularly over the Iberian Peninsula. Intense, high-impact storms are one of the major weather risks in the region, mostly due to the simultaneous occurrence of high winds and extreme precipitation events. These intense extratropical cyclones may result in windstorm damage, flooding and coastal storm surges, with large societal impacts. In Portugal, due to the extensive human use of coastal areas, the natural and built coastal environments have been amongst the most affected. In this work several historical winter storms that adversely affected the Western Iberian Peninsula are studied in detail in order to contribute to an improved assessment of the characteristics of these events. The diagnosis has been performed based on instrumental daily precipitation and wind records, on satellite images, on reanalysis data and through model simulations. For several examples the synoptic evolution and upper-level dynamics analysis of physical processes controlling the life cycle of extratropical storms associated with the triggering of the considered extreme events has also been accomplished. Furthermore, the space-time variability of the exceptionally severe storms affecting Western Iberia over the last century and under three climate scenarios (the historical simulation, the RCP4.5 and RCP8.5 scenarios) is presented. These studies contribute to improving the knowledge of atmospheric dynamics controlling the life cycle of midlatitude storms associated to severe weather (precipitation and wind) in the Iberian Peninsula. AcknowledgementsThis work is supported by the Portuguese Foundation for Science and Technology (FCT), Portugal, through project UID/GEO/50019/2013 - Instituto Dom Luiz. A. M. Ramos is also supported by a FCT postdoctoral grant (FCT/DFRH/SFRH/BPD/84328/2012).

  3. The differences between storms driven by helmet streamer CIRs and storms driven by pseudostreamer CIRs

    OpenAIRE

    Borovsky, Joseph E.; Denton, Michael

    2013-01-01

    A corotating interaction region (CIR) is formed when fast coronal hole origin solar wind overtakes slow solar wind and forms a region of compressed plasma and magnetic field. The slow wind upstream of the coronal hole fast wind can be either of helmet streamer origin or pseudostreamer origin. For a collection of 125 CIR-driven geomagnetic storms, the slow wind ahead of each CIR is examined; for those storm not containing ejecta, each CIR is categorized as a helmet streamer CIR (74 of the 125 ...

  4. Geomagnetic storm effects on GPS based navigation

    Directory of Open Access Journals (Sweden)

    P. V. S. Rama Rao

    2009-05-01

    Full Text Available The energetic events on the sun, solar wind and subsequent effects on the Earth's geomagnetic field and upper atmosphere (ionosphere comprise space weather. Modern navigation systems that use radio-wave signals, reflecting from or propagating through the ionosphere as a means of determining range or distance, are vulnerable to a variety of effects that can degrade the performance of the navigational systems. In particular, the Global Positioning System (GPS that uses a constellation of earth orbiting satellites are affected due to the space weather phenomena.

    Studies made during two successive geomagnetic storms that occurred during the period from 8 to 12 November 2004, have clearly revealed the adverse affects on the GPS range delay as inferred from the Total Electron Content (TEC measurements made from a chain of seven dual frequency GPS receivers installed in the Indian sector. Significant increases in TEC at the Equatorial Ionization anomaly crest region are observed, resulting in increased range delay during the periods of the storm activity. Further, the storm time rapid changes occurring in TEC resulted in a number of phase slips in the GPS signal compared to those on quiet days. These phase slips often result in the loss of lock of the GPS receivers, similar to those that occur during strong(>10 dB L-band scintillation events, adversely affecting the GPS based navigation.

  5. New forecasting methods of the intensity and time development of geomagnetic and ionospheric storms

    International Nuclear Information System (INIS)

    Akasofu, S.I.

    1981-01-01

    The main phase of a geomagnetic storm develops differently from one storm to another. A description is given of the solar wind quantity which controls directly the development of the main phase of geomagnetic storms. The parameters involved include the solar wind speed, the magnetic field intensity, and the polar angle of the solar wind magnetic field projected onto the dawn-dusk plane. A redefinition of geomagnetic storm and auroral activity is given. It is pointed out that geomagnetic disturbances are caused by the magnetic fields of electric currents which are generated by the solar wind-magnetosphere dynamo. Attention is given to approaches for forecasting the occurrence and intensity of geomagnetic storms and ionospheric disturbances

  6. Empirical STORM-E Model. [I. Theoretical and Observational Basis

    Science.gov (United States)

    Mertens, Christopher J.; Xu, Xiaojing; Bilitza, Dieter; Mlynczak, Martin G.; Russell, James M., III

    2013-01-01

    Auroral nighttime infrared emission observed by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument onboard the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) satellite is used to develop an empirical model of geomagnetic storm enhancements to E-region peak electron densities. The empirical model is called STORM-E and will be incorporated into the 2012 release of the International Reference Ionosphere (IRI). The proxy for characterizing the E-region response to geomagnetic forcing is NO+(v) volume emission rates (VER) derived from the TIMED/SABER 4.3 lm channel limb radiance measurements. The storm-time response of the NO+(v) 4.3 lm VER is sensitive to auroral particle precipitation. A statistical database of storm-time to climatological quiet-time ratios of SABER-observed NO+(v) 4.3 lm VER are fit to widely available geomagnetic indices using the theoretical framework of linear impulse-response theory. The STORM-E model provides a dynamic storm-time correction factor to adjust a known quiescent E-region electron density peak concentration for geomagnetic enhancements due to auroral particle precipitation. Part II of this series describes the explicit development of the empirical storm-time correction factor for E-region peak electron densities, and shows comparisons of E-region electron densities between STORM-E predictions and incoherent scatter radar measurements. In this paper, Part I of the series, the efficacy of using SABER-derived NO+(v) VER as a proxy for the E-region response to solar-geomagnetic disturbances is presented. Furthermore, a detailed description of the algorithms and methodologies used to derive NO+(v) VER from SABER 4.3 lm limb emission measurements is given. Finally, an assessment of key uncertainties in retrieving NO+(v) VER is presented

  7. Onset of frequent dust storms in northern China at ~AD 1100.

    Science.gov (United States)

    He, Yuxin; Zhao, Cheng; Song, Mu; Liu, Weiguo; Chen, Fahu; Zhang, Dian; Liu, Zhonghui

    2015-11-26

    Dust storms in northern China strongly affect the living and health of people there and the dusts could travel a full circle of the globe in a short time. Historically, more frequent dust storms occurred during cool periods, particularly the Little Ice Age (LIA), generally attributed to the strengthened Siberian High. However, limited by chronological uncertainties in proxy records, this mechanism may not fully reveal the causes of dust storm frequency changes. Here we present a late Holocene dust record from the Qaidam Basin, where hydrological changes were previously reconstructed, and examine dust records from northern China, including the ones from historical documents. The records, being broadly consistent, indicate the onset of frequent dust storms at ~AD 1100. Further, peaked dust storm events occurred at episodes of high total solar irradiance or warm-dry conditions in source regions, superimposed on the high background of frequent dust storms within the cool LIA period. We thus suggest that besides strong wind activities, the centennial-scale dust storm events over the last 1000 years appear to be linked to the increased availability of dust source. With the anticipated global warming and deteriorating vegetation coverage, frequent occurrence of dust storms in northern China would be expected to persist.

  8. Coronal mass ejections and large geomagnetic storms

    International Nuclear Information System (INIS)

    Gosling, J.T.; Bame, S.J.; McComas, D.J.; Phillips, J.L.

    1990-01-01

    Previous work indicates that coronal mass ejection (CME) events in the solar wind at 1 AU can be identified by the presence of a flux of counterstreaming solar wind halo electrons (above about 80 eV). Using this technique to identify CMEs in 1 AU plasma data, the authors find that most large geomagnetic storms during the interval surrounding the last solar maximum (Aug. 1978-Oct. 1982) were associated with Earth-passage of interplanetary disturbances in which the Earth encountered both a shock and the CME driving the shock. However, only about one CME in six encountered by Earth was effective in causing a large geomagnetic storm. Slow CMEs which did not interact strongly with the ambient solar wind ahead were particularly ineffective in a geomagnetic sense

  9. Automated detection of geomagnetic storms with heightened risk of GIC

    Science.gov (United States)

    Bailey, Rachel L.; Leonhardt, Roman

    2016-06-01

    Automated detection of geomagnetic storms is of growing importance to operators of technical infrastructure (e.g., power grids, satellites), which is susceptible to damage caused by the consequences of geomagnetic storms. In this study, we compare three methods for automated geomagnetic storm detection: a method analyzing the first derivative of the geomagnetic variations, another looking at the Akaike information criterion, and a third using multi-resolution analysis of the maximal overlap discrete wavelet transform of the variations. These detection methods are used in combination with an algorithm for the detection of coronal mass ejection shock fronts in ACE solar wind data prior to the storm arrival on Earth as an additional constraint for possible storm detection. The maximal overlap discrete wavelet transform is found to be the most accurate of the detection methods. The final storm detection software, implementing analysis of both satellite solar wind and geomagnetic ground data, detects 14 of 15 more powerful geomagnetic storms over a period of 2 years.

  10. Prediction of SYM-H index during large storms by NARX neural network from IMF and solar wind data

    Directory of Open Access Journals (Sweden)

    L. Cai

    2010-02-01

    Full Text Available Similar to the Dst index, the SYM-H index may also serve as an indicator of magnetic storm intensity, but having distinct advantage of higher time-resolution. In this study the NARX neural network has been used for the first time to predict SYM-H index from solar wind (SW and IMF parameters. In total 73 time intervals of great storm events with IMF/SW data available from ACE satellite during 1998 to 2006 are used to establish the ANN model. Out of them, 67 are used to train the network and the other 6 samples for test. Additionally, the NARX prediction model is also validated using IMF/SW data from WIND satellite for 7 great storms during 1995–1997 and 2005, as well as for the July 2000 Bastille day storm and November 2001 superstorm using Geotail and OMNI data at 1 AU, respectively. Five interplanetary parameters of IMF Bz, By and total B components along with proton density and velocity of solar wind are used as the original external inputs of the neural network to predict the SYM-H index about one hour ahead. For the 6 test storms registered by ACE including two super-storms of min. SYM-H<−200 nT, the correlation coefficient between observed and NARX network predicted SYM-H is 0.95 as a whole, even as high as 0.95 and 0.98 with average relative variance of 13.2% and 7.4%, respectively, for the two super-storms. The prediction for the 7 storms with WIND data is also satisfactory, showing averaged correlation coefficient about 0.91 and RMSE of 14.2 nT. The newly developed NARX model shows much better capability than Elman network for SYM-H prediction, which can partly be attributed to a key feedback to the input layer from the output neuron with a suitable length (about 120 min. This feedback means that nearly real information of the ring current status is effectively directed to take part in the prediction of SYM-H index by ANN. The proper history length of the output-feedback may mainly reflect

  11. Prediction of SYM-H index during large storms by NARX neural network from IMF and solar wind data

    Directory of Open Access Journals (Sweden)

    L. Cai

    2010-02-01

    Full Text Available Similar to the Dst index, the SYM-H index may also serve as an indicator of magnetic storm intensity, but having distinct advantage of higher time-resolution. In this study the NARX neural network has been used for the first time to predict SYM-H index from solar wind (SW and IMF parameters. In total 73 time intervals of great storm events with IMF/SW data available from ACE satellite during 1998 to 2006 are used to establish the ANN model. Out of them, 67 are used to train the network and the other 6 samples for test. Additionally, the NARX prediction model is also validated using IMF/SW data from WIND satellite for 7 great storms during 1995–1997 and 2005, as well as for the July 2000 Bastille day storm and November 2001 superstorm using Geotail and OMNI data at 1 AU, respectively. Five interplanetary parameters of IMF Bz, By and total B components along with proton density and velocity of solar wind are used as the original external inputs of the neural network to predict the SYM-H index about one hour ahead. For the 6 test storms registered by ACE including two super-storms of min. SYM-H<−200 nT, the correlation coefficient between observed and NARX network predicted SYM-H is 0.95 as a whole, even as high as 0.95 and 0.98 with average relative variance of 13.2% and 7.4%, respectively, for the two super-storms. The prediction for the 7 storms with WIND data is also satisfactory, showing averaged correlation coefficient about 0.91 and RMSE of 14.2 nT. The newly developed NARX model shows much better capability than Elman network for SYM-H prediction, which can partly be attributed to a key feedback to the input layer from the output neuron with a suitable length (about 120 min. This feedback means that nearly real information of the ring current status is effectively directed to take part in the prediction of SYM-H index by ANN. The proper history length of the output-feedback may mainly reflect on average the characteristic time of ring

  12. Statistical Relationship between Sawtooth Oscillations and Geomagnetic Storms

    Directory of Open Access Journals (Sweden)

    Jae-Hun Kim

    2008-06-01

    Full Text Available We have investigated a statistical relationship between sawtooth oscillations and geomagnetic storms during 2000-2004. First of all we selected a total of 154 geomagnetic storms based on the Dst index, and distinguished between different drivers such as Coronal Mass Ejection (CME and Co-rotating Interaction Region (CIR. Also, we identified a total of 48 sawtooth oscillation events based on geosynchronous energetic particle data for the same 2000-2004 period. We found that out of the 154 storms identified, 47 storms indicated the presence of sawtooth oscillations. Also, all but one sawtooth event identified occurred during a geomagnetic storm interval. It was also found that sawtooth oscillation events occur more frequently for storms driven by CME (˜62% than for storms driven by CIR (˜30%. In addition, sawtooth oscillations occurred mainly (˜82% in the main phase of storms for CME-driven storms while they occurred mostly (˜78% during the storm recovery phase for CIR-driven storms. Next we have examined the average characteristics of the Bz component of IMF, and solar wind speed, which were the main components for driving geomagnetic storm. We found that for most of the sawtooth events, the IMF Bz corresponds to --15 to 0 nT and the solar wind speed was in the range of 400˜700 km/s. We found that there was a weak tendency that the number of teeth for a given sawtooth event interval was proportional to the southward IMF Bz magnitude.

  13. Magnetic Storms at Mars and Earth

    DEFF Research Database (Denmark)

    Vennerstrøm, Susanne; Falkenberg, Thea Vilstrup

    In analogy with magnetic storms at the Earth, periods of significantly enhanced global magnetic activity also exist at Mars. The extensive database of magnetic measurements from Mars Global Surveyor (MGS), covering almost an entire solar cycle, is used in combination with geomagnetic activity...... indices at Earth to compare the occurrence of magnetic storms at Mars and Earth. Based on superposed epochs analysis the time-development of typical magnetic storms at Mars and Earth is described. In contradiction to storms at Earth, most magnetic storms at Mars are found to be associated...... with heliospheric current sheet crossings, where the IMF changes polarity. While most storms at the Earth occur due to significant southward excursions of the IMF associated with CMEs, at Mars most storms seem to be associated with the density enhancement of the heliospheric current sheet. Density enhancements...

  14. On the effects of solar storms to the decaying orbital space debris

    International Nuclear Information System (INIS)

    Herdiwijaya, Dhani; Rachman, Abdul

    2014-01-01

    Any man-made object in Earth's orbit that no longer serves a useful purpose is classified as orbital debris. Debris objects come from a variety of sources. The majority is related to satellite fragmentation. Other major sources of debris are propulsion systems, and fragmentation of spent upper stages, payload and mission related debris. Serious concern about orbital debris has been growing. Knowledge of the future debris environment is important to both satellite designers, and mission planners, who need to know what hazards a satellite might encounter during the course of its mission. Therefore, it is important to know how much debris is in orbit, where it is located, and when it will decay. The debris environment is complex and dynamically evolving. Objects of different shape and size behave differently in orbit. The geoeffectiveness space environments include solar flux at 10.7 cm, solar energetic particles flux or speed, solar wind flow pressure, electric field, and geomagnetic indices. We study the decaying orbital debris from Tracking and Impact Prediction (TIP) messages in conjuction with geoeffectiveness space environments through time epoch correlation. We found that the decaying and reentry orbital debris are triggered by space environment enhancement within at least one week before reentry. It is not necessary a transient or high energetic and severe solar storm events are needed in decaying processes. We propose that the gradual enhancement processes of space environment will cause satellite surface charging due to energetic electron and enhance drag force

  15. On the effects of solar storms to the decaying orbital space debris

    Energy Technology Data Exchange (ETDEWEB)

    Herdiwijaya, Dhani, E-mail: dhani@as.itb.ac.id [Astronomy Division and Bosscha Observatory, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Ganesha 10, Bandung 40132 (Indonesia); Rachman, Abdul [Space Science Center, National Institute of Aeronautics and Space, Junjunan 133, Bandung 40173 (Indonesia)

    2014-03-24

    Any man-made object in Earth's orbit that no longer serves a useful purpose is classified as orbital debris. Debris objects come from a variety of sources. The majority is related to satellite fragmentation. Other major sources of debris are propulsion systems, and fragmentation of spent upper stages, payload and mission related debris. Serious concern about orbital debris has been growing. Knowledge of the future debris environment is important to both satellite designers, and mission planners, who need to know what hazards a satellite might encounter during the course of its mission. Therefore, it is important to know how much debris is in orbit, where it is located, and when it will decay. The debris environment is complex and dynamically evolving. Objects of different shape and size behave differently in orbit. The geoeffectiveness space environments include solar flux at 10.7 cm, solar energetic particles flux or speed, solar wind flow pressure, electric field, and geomagnetic indices. We study the decaying orbital debris from Tracking and Impact Prediction (TIP) messages in conjuction with geoeffectiveness space environments through time epoch correlation. We found that the decaying and reentry orbital debris are triggered by space environment enhancement within at least one week before reentry. It is not necessary a transient or high energetic and severe solar storm events are needed in decaying processes. We propose that the gradual enhancement processes of space environment will cause satellite surface charging due to energetic electron and enhance drag force.

  16. Jupiter's Spot Seen Glowing - Scientists Get First Look at Weather Inside the Solar System's Biggest Storm

    Science.gov (United States)

    2010-03-01

    New ground-breaking thermal images obtained with ESO's Very Large Telescope and other powerful ground-based telescopes show swirls of warmer air and cooler regions never seen before within Jupiter's Great Red Spot, enabling scientists to make the first detailed interior weather map of the giant storm system linking its temperature, winds, pressure and composition with its colour. "This is our first detailed look inside the biggest storm of the Solar System," says Glenn Orton, who led the team of astronomers that made the study. "We once thought the Great Red Spot was a plain old oval without much structure, but these new results show that it is, in fact, extremely complicated." The observations reveal that the reddest colour of the Great Red Spot corresponds to a warm core within the otherwise cold storm system, and images show dark lanes at the edge of the storm where gases are descending into the deeper regions of the planet. The observations, detailed in a paper appearing in the journal Icarus, give scientists a sense of the circulation patterns within the solar system's best-known storm system. Sky gazers have been observing the Great Red Spot in one form or another for hundreds of years, with continuous observations of its current shape dating back to the 19th century. The spot, which is a cold region averaging about -160 degrees Celsius, is so wide that about three Earths could fit inside its boundaries. The thermal images were mostly obtained with the VISIR [1] instrument attached to ESO's Very Large Telescope in Chile, with additional data coming from the Gemini South telescope in Chile and the National Astronomical Observatory of Japan's Subaru Telescope in Hawaii. The images have provided an unprecedented level of resolution and extended the coverage provided by NASA's Galileo spacecraft in the late 1990s. Together with observations of the deep cloud structure by the 3-metre NASA Infrared Telescope Facility in Hawaii, the level of thermal detail observed

  17. Role of the lifetime of ring current particles on the solar wind-magnetosphere power transfer during the intense geomagnetic storm of 28 August 1978

    International Nuclear Information System (INIS)

    Gonzalez, W.D.; Gonzalez, A.L.C.; Lee, L.C.

    1990-01-01

    For the intense magnetic storms of 28 August 1978 it is shown that the power transfer from the solar wind to the magnetosphere is well represented by the expression obtained by Vasyliunas et al. (1982, Planet. Space Sci. 30, 359) from dimensional analysis, but this representation becomes improved when such an expression is modified by a factor due to an influence of the lifetime of ring current particles as suggested by Lee and Akasofu (1984, Planet. Space Sci. 32, 1423). During a steady state regime of the ring current evolution of this storm, our study suggests that the power transfer depends on the solar wind density, the transverse component of the IMF (Interplanetary magnetic field) (with respect to the Sun-Earth line) and also, explicitly, on the time constant for ring current energy decay, but not on the solar wind speed. (author)

  18. Statistical Analysis of Solar Events Associated with Storm Sudden Commencements over One Year of Solar Maximum During Cycle 23: Propagation from the Sun to the Earth and Effects

    Science.gov (United States)

    Bocchialini, K.; Grison, B.; Menvielle, M.; Chambodut, A.; Cornilleau-Wehrlin, N.; Fontaine, D.; Marchaudon, A.; Pick, M.; Pitout, F.; Schmieder, B.; Régnier, S.; Zouganelis, I.

    2018-05-01

    Taking the 32 storm sudden commencements (SSCs) listed by the International Service of Geomagnetic Indices (ISGI) of the Observatory de l'Ebre during 2002 (solar activity maximum in Cycle 23) as a starting point, we performed a multi-criterion analysis based on observations (propagation time, velocity comparisons, sense of the magnetic field rotation, radio waves) to associate them with solar sources, identified their effects in the interplanetary medium, and looked at the response of the terrestrial ionized and neutral environment. We find that 28 SSCs can be related to 44 coronal mass ejections (CMEs), 15 with a unique CME and 13 with a series of multiple CMEs, among which 19 (68%) involved halo CMEs. Twelve of the 19 fastest CMEs with speeds greater than 1000 km s-1 are halo CMEs. For the 44 CMEs, including 21 halo CMEs, the corresponding X-ray flare classes are: 3 X-class, 19 M-class, and 22 C-class flares. The probability for an SSC to occur is 75% if the CME is a halo CME. Among the 500, or even more, front-side, non-halo CMEs recorded in 2002, only 23 could be the source of an SSC, i.e. 5%. The complex interactions between two (or more) CMEs and the modification of their trajectories have been examined using joint white-light and multiple-wavelength radio observations. The detection of long-lasting type IV bursts observed at metric-hectometric wavelengths is a very useful criterion for the CME-SSC events association. The events associated with the most depressed Dst values are also associated with type IV radio bursts. The four SSCs associated with a single shock at L1 correspond to four radio events exhibiting characteristics different from type IV radio bursts. The solar-wind structures at L1 after the 32 SSCs are 12 magnetic clouds (MCs), 6 interplanetary coronal mass ejections (ICMEs) without an MC structure, 4 miscellaneous structures, which cannot unambiguously be classified as ICMEs, 5 corotating or stream interaction regions (CIRs/SIRs), one CIR

  19. Apparent Relations Between Solar Activity and Solar Tides Caused by the Planets

    Science.gov (United States)

    Hung, Ching-Cheh

    2007-01-01

    A solar storm is a storm of ions and electrons from the Sun. Large solar storms are usually preceded by solar flares, phenomena that can be characterized quantitatively from Earth. Twenty-five of the thirty-eight largest known solar flares were observed to start when one or more tide-producing planets (Mercury, Venus, Earth, and Jupiter) were either nearly above the event positions (less than 10 deg. longitude) or at the opposing side of the Sun. The probability for this to happen at random is 0.039 percent. This supports the hypothesis that the force or momentum balance (between the solar atmospheric pressure, the gravity field, and magnetic field) on plasma in the looping magnetic field lines in solar corona could be disturbed by tides, resulting in magnetic field reconnection, solar flares, and solar storms. Separately, from the daily position data of Venus, Earth, and Jupiter, an 11-year planet alignment cycle is observed to approximately match the sunspot cycle. This observation supports the hypothesis that the resonance and beat between the solar tide cycle and nontidal solar activity cycle influences the sunspot cycle and its varying magnitudes. The above relations between the unpredictable solar flares and the predictable solar tidal effects could be used and further developed to forecast the dangerous space weather and therefore reduce its destructive power against the humans in space and satellites controlling mobile phones and global positioning satellite (GPS) systems.

  20. Evaluation of geomagnetic storm effects on the GPS derived Total Electron Content (TEC)

    International Nuclear Information System (INIS)

    Purohit, P K; Atulkar, Roshni; Mansoori, Azad A; Khan, Parvaiz A; Bhawre, Purushottam; Tripathi, Sharad C; Khatarkar, Prakash; Bhardwaj, Shivangi; Aslam, A M; Waheed, Malik A; Gwal, A K

    2015-01-01

    The geomagnetic storm represents the most outstanding example of solar wind- magnetospheric interaction, which causes global disturbances in the geomagnetic field as well as triggers ionospheric disturbances. We study the behaviour of ionospheric Total Electron Content (TEC) during the geomagnetic storms. For this investigation we have selected 47 intense geomagnetic storms (Dst ≤ -100nT) that were observed during the solar cycle 23 i.e. during 1998- 2006. We then categorized these storms into four categories depending upon their solar sources like Magnetic Cloud (MC), Co-rotating Interaction Region (CIR), SH+ICME and SH+MC. We then studied the behaviour of ionospheric TEC at a mid latitude station Usuda (36.13N, 138.36E), Japan during these storm events produced by four different solar sources. During our study we found that the smooth variations in TEC are replaced by rapid fluctuations and the value of TEC is strongly enhanced during the time of these storms belonging to all the four categories. However, the greatest enhancements in TEC are produced during those geomagnetic storms which are either caused by Sheath driven Magnetic cloud (SH+MC) or Sheath driven ICME (SH+ICME). We also derived the correlation between the TEC enhancements produced during storms of each category with the minimum Dst. We found the strongest correlation exists for the SH+ICME category followed by SH+MC, MC and finally CIR. Since the most intense storms were either caused by SH+ICME or SH+MC while the least intense storms were caused by CIR, consequently the correlation was strongest with SH+ICME and SH+MC and least with CIR. (paper)

  1. Role of neutral wind and storm time electric fields inferred from the storm time ionization distribution at low latitudes: in-situ measurements by Indian satellite SROSS-C2

    OpenAIRE

    Subrahmanyam , P.; Jain , A. R.; Singh , L.; Garg , S. C.

    2005-01-01

    Recently, there has been a renewal of interest in the study of the effects of solar weather events on the ionization redistribution and irregularity generation. The observed changes at low and equatorial latitudes are rather complex and are noted to be a function of location, the time of the storm onset and its intensity, and various other characteristics of the geomagnetic storms triggered by solar weather events. At these latitudes, the effects of geomagnetic storms are basically due to (a)...

  2. Magnetic storm injection of 0.9- to 16-keV/e solar and terrestrial ions into the high-altitude magnetosphere

    International Nuclear Information System (INIS)

    Balsiger, H.; Eberhardt, P.; Geiss, J.; Young, D.T.

    1980-01-01

    The Geos 1 ion composition experiments has surveyed the plasma composition in the energy per charge range below 16 keV/e at all local times and at L=3--8. During quiet and moderately disturbed times, H + is the dominant species with a few percent of heavy (M/Q>1) ions. Substorms and storms increase the relative amount of heavy ions, and occasionally, they can become the dominant species in the outer magnetosphere. Two sources, the solar wind (characterized by 4 He ++ ) and the ionosphere (characterized by O + ), give on the average comparable contributions to storm time plasma, although in individual storms one or the other may dominate. Data presented here suggest that high-altitude thermal plasma or the plasmasphere (characterized by He + and O ++ ) must be considered as a third source. Under storm conditions with Geos in the dawn-noon local time sector we have observed a mixed composition region just inside the magnetopause where high fluxes of H + , He ++ , O + , and occasionally He + ions are present. During several storms a composition profile could be measured down to Lapprox.3. Both O + and He + increase toward low altitudes, and O + (within our energy range) can become dominant at the inner edge of the ring current. On April 30, 1978, during a storm, O + contributed > or approx. =8% to the total local energy density of the ring current particles at L=4.1. In no storm has He + been observed to be the main constituent during the recovery phase. During storm recovery, H + and O + are the dominant ions, the H + /O + ratio remaining constant or even increasing during the days following the main phase of the storms. This suggests that charge exchange is not the only loss mechanism for the storm time ring current and/or that H + is replenished during the recovery phase

  3. Eruptive prominences and long-delay geomagnetic storms

    International Nuclear Information System (INIS)

    Wright, C.S.

    1983-01-01

    The relationship between disappearing solar fragments and geomagnetic disturbances was investigated. It is shown that long-delay storms are associated with filaments well removed from the disc centre, and particularly in the case of large filaments and prominences, the proportion of events that produce long-delay storms increases with angular distance from the centre

  4. Solar effects on communications

    International Nuclear Information System (INIS)

    Cleveland, F.; Malcolm, W.; Nordell, D.E.; Zirker, J.

    1991-01-01

    When people involved in the power industry think of Solar Magnetic Disturbances (SMD), they normally consider the potential for disrupting power transmission which results form solar-induced disturbances to the earth's magnetic field known as geomagnetic storms. However, in addition to the disruption of power transmission, solar phenomena can interfere with utility communication systems. Utilities use many different types of communication media, some of which can be affected by various solar phenomena. These include wire-based facilities (metallic cables and power line carrier), radio systems (HF, VHF, UHF mobile radio, microwave networks, and satellite transmissions), and fiber optic systems. This paper reports that the solar flares and other solar phenomena can affect these media through different mechanisms: Radio communications can be disturbed by flare-induced changes in the ionispheric layer of the atmosphere; Cable communications can be disrupted by the flare-induced changes in the magnetosphere which surrounds the earth. These changes, in turn, induce currents in the power equipment that energizes long communications cables; Satellite communications can be disrupted by the flare-induced perturbations of satellite orbits and equipment

  5. Solar-terrestrial disturbances in June-September 1982, 5

    International Nuclear Information System (INIS)

    Ondoh, Tadanori

    1985-01-01

    The x-ray detector on the SMS-GOES satellite observed 77 solar x-ray flares (1 - 8A) with flux above 10 -5 W/m 2 in June, 1982, and 33 SIDs with importance above 2 were observed in Hiraiso, Japan. However, the geomagnetic storm with Dst above 100 nT did not occur at that time since most solar flares occurred near the east rim of the sun. These solar active regions lasted for 5 solar rotations, then, the great geomagnetic storms with Dst above 100 nT occurred on July 13 - 15, September 5 - 7 and September 21 - 23, 1982. These geomagnetic storms were preceded by the solar flares of importance above 2B occurred in the central part of the solar disc. From September 26 to 27, 1982, a great geomagnetic storm which was not accompanied by solar flare occurred. This paper summarized the studies on solar-terrestrial events from June to September, 1982, made by the space physics and aeronomy groups of the Radio Research Laboratories, Japan. The solar flares occurred on July 12, September 4 and 19, 1982, the geomagnetic storms corresponding to them, the cosmic ray storms observed on July 13 - 19, September 6 - 9 and 21 - 26, 1982, global equivalent current system and others are reported. (Kako, I.)

  6. Coronal mass ejections, interplanetary shocks in relation with forbush decreases associated with intense geomagnetic storms

    International Nuclear Information System (INIS)

    Verma, P L; Patel, Nand Kumar; Prajapati, Mateswari

    2014-01-01

    Coronal mass ejections (CMEs} are the most energetic solar events in which large amount of solar plasma materials are ejected from the sun into heliosphere, causing major disturbances in solar wind plasma, Interplanetary shocks, Forbush decrease(Fds) in cosmic ray intensity and geomagnetic storms. We have studied Forbush decreases associated with intense geomagnetic storms observed at Oulu super neutron monitor, during the period of May 1998-Dec 2006 with coronal mass ejections (CMEs), X-ray solar flares and interplanetary shocks. We have found that all the (100%) Forbush decreases associated with intense geomagnetic storms are associated with halo and partial halo coronal mass ejections (CMEs). The association rate between halo and partial halo coronal mass ejections are found 96.00%and 04.00% respectively. Most of the Forbush decreases associated with intense geomagnetic storms (96.29%) are associated with X-ray solar flares of different categories . The association rates for X-Class, M-Class, and C- Class X -ray solar flares are found 34.62%, 50.00% and 15.38% respectively .Further we have concluded that majority of the Forbush decrease associated with intense geomagnetic storms are related to interplanetary shocks (92.30 %) and the related shocks are forward shocks. We have found positive co-relation with co-relation co-efficient .7025 between magnitudes of Forbush decreases associated with intense geomagnetic storms and speed of associated coronal mass ejections. Positive co-relation with co-relation co-efficient 0.48 has also been found between magnitudes of intense geomagnetic storms and speed of associated coronal mass ejections.

  7. A study of solar and interplanetary parameters of CMEs causing major geomagnetic storms during SC 23

    Directory of Open Access Journals (Sweden)

    C. Oprea

    2013-08-01

    Full Text Available In this paper we analyse 25 Earth-directed and strongly geoeffective interplanetary coronal mass ejections (ICMEs which occurred during solar cycle 23, using data provided by instruments on SOHO (Solar and Heliospheric Observatory, ACE (Advanced Composition Explorer and geomagnetic stations. We also examine the in situ parameters, the energy transfer into magnetosphere, and the geomagnetic indexes. We compare observed travel times with those calculated by observed speeds projected into the plane of the sky and de-projected by a simple model. The best fit was found with the projected speeds. No correlation was found between the importance of a flare and the geomagnetic Dst (disturbance storm time index. By comparing the in situ parameters with the Dst index we find a strong connection between some of these parameters (such as Bz, Bs · V and the energy transfer into the magnetosphere with the strength of the geomagnetic storm. No correlation was found with proton density and plasma temperature. A superposed epoch analysis revealed a strong dependence of the Dst index on the southward component of interplanetary magnetic field, Bz, and to the Akasofu coupling function, which evaluates the energy transfer between the ICME and the magnetosphere. The analysis also showed that the geomagnetic field at higher latitudes is disturbed before the field around the Earth's equator.

  8. Effects of geomagnetic storms in the lower ionosphere, middle atmosphere and troposphere.

    Science.gov (United States)

    Lastovicka, J.

    1996-05-01

    Geomagnetic storm effects at heights of about 0-100 km are briefly (not comprehensively) reviewed, with emphasis being paid to middle latitudes, particularly to Europe. Effects of galactic cosmic rays, solar particle events, relativistic and highly relativistic electrons, and IMF sector boundary crossings are briefly mentioned as well. Geomagnetic storms disturb the lower ionosphere heavily at high latitudes and very significantly also at middle latitudes. The effect is almost simultaneous at high latitudes, while an after-effect dominates at middle latitudes. The lower thermosphere is disturbed significantly. In the mesosphere and stratosphere, the effects become weaker and eventually non-detectable. There is an effect in total ozone but only under special conditions. Surprisingly enough, correlations with geomagnetic storms seem to reappear in the troposphere, particularly in the Northern Hemisphere. Atmospheric electricity is affected by geomagnetic storms, as well. We essentially understand the effects of geomagnetic storms in the lower ionosphere, but there is a lack of mechanisms to explain correlations found deeper in the atmosphere, particularly in the troposphere. There seem to be two different groups of effects with possibly different mechanisms - those observed in the lower ionosphere, lower thermosphere and mesosphere, and those observed in the troposphere.

  9. An operational integrated short-term warning solution for solar radiation storms: introducing the Forecasting Solar Particle Events and Flares (FORSPEF) system

    Science.gov (United States)

    Anastasiadis, Anastasios; Sandberg, Ingmar; Papaioannou, Athanasios; Georgoulis, Manolis; Tziotziou, Kostas; Jiggens, Piers; Hilgers, Alain

    2015-04-01

    We present a novel integrated prediction system, of both solar flares and solar energetic particle (SEP) events, which is in place to provide short-term warnings for hazardous solar radiation storms. FORSPEF system provides forecasting of solar eruptive events, such as solar flares with a projection to coronal mass ejections (CMEs) (occurrence and velocity) and the likelihood of occurrence of a SEP event. It also provides nowcasting of SEP events based on actual solar flare and CME near real-time alerts, as well as SEP characteristics (peak flux, fluence, rise time, duration) per parent solar event. The prediction of solar flares relies on a morphological method which is based on the sophisticated derivation of the effective connected magnetic field strength (Beff) of potentially flaring active-region (AR) magnetic configurations and it utilizes analysis of a large number of AR magnetograms. For the prediction of SEP events a new reductive statistical method has been implemented based on a newly constructed database of solar flares, CMEs and SEP events that covers a large time span from 1984-2013. The method is based on flare location (longitude), flare size (maximum soft X-ray intensity), and the occurrence (or not) of a CME. Warnings are issued for all > C1.0 soft X-ray flares. The warning time in the forecasting scheme extends to 24 hours with a refresh rate of 3 hours while the respective warning time for the nowcasting scheme depends on the availability of the near real-time data and falls between 15-20 minutes. We discuss the modules of the FORSPEF system, their interconnection and the operational set up. The dual approach in the development of FORPSEF (i.e. forecasting and nowcasting scheme) permits the refinement of predictions upon the availability of new data that characterize changes on the Sun and the interplanetary space, while the combined usage of solar flare and SEP forecasting methods upgrades FORSPEF to an integrated forecasting solution. This

  10. New insights on geomagnetic storms from observations and modeling

    Energy Technology Data Exchange (ETDEWEB)

    Jordanova, Vania K [Los Alamos National Laboratory

    2009-01-01

    Understanding the response at Earth of the Sun's varying energy output and forecasting geomagnetic activity is of central interest to space science, since intense geomagnetic storms may cause severe damages on technological systems and affect communications. Episodes of southward (Bzsolar wind streams (HSS) whose geoeffectiveness is due to IMF Bz profiles fluctuating about zero with various amplitudes and duration. We show examples of ring current simulations during two geomagnetic storms representative of each interplanetary condition with our kinetic ring current atmosphere interactions model (RAM), and investigate the mechanisms responsible for trapping particles and for causing their loss. We find that periods of increased magnetospheric convection coinciding with enhancements of plasma sheet density are needed for strong ring current buildup. During the HSS-driven storm the convection potential is highly variable and causes small sporadic injections into the ring current. The long period of enhanced convection during the CME-driven storm causes a continuous ring current injection penetrating to lower L shells and stronger ring current buildup.

  11. Interplanetary sources of magnetic storms: A statistical study

    DEFF Research Database (Denmark)

    Vennerstrøm, Susanne

    2001-01-01

    Magnetic storms are mainly caused by the occurrence of intense southward magnetic fields in the interplanetary medium. These fields can be formed directly either by ejection of magnetic structures from the Sun or by stream interaction processes during solar wind propagation. In the present study we...... examine 30 years of satellite measurement of the solar wind during magnetic storms, with the aim of estimating the relative importance of these two processes. We use the solar wind proton temperature relative to the temperature expected from the empirical relation to the solar wind speed T......-p/T-exp, together with the speed gradient, and the interplanetary magnetic field azimuth in the ecliptic, in order to distinguish between the two processes statistically. We find that compression due to stream interaction is at least as important as the direct effect of ejection of intense fields, and probably more...

  12. Interplanetary sources to magnetic storms - A statistical study

    DEFF Research Database (Denmark)

    Vennerstrøm, Susanne

    2001-01-01

    Magnetic storms are mainly caused by the occurrence of intense southward magnetic fields in the interplanetary medium. These fields can be formed directly either by ejection of magnetic structures from the Sun or by stream interaction processes during solar wind propagation. In the present study we...... examine 30 years of satellite measurement of the solar wind during magnetic storms, with the aim of estimating the relative importance of these two processes. We use the solar wind proton temperature relative to the temperature expected from the empirical relation to the solar wind speed Tp/Texp, together...... with the speed gradient, and the interplanetary magnetic field azimuth in the ecliptic, in order to distinguish between the two processes statistically. We find that compression due to stream interaction is at least as important as the direct effect of ejection of intense fields, and probably more so. Only...

  13. Interplanetary ions during an energetic storm particle event - The distribution function from solar wind thermal energies to 1.6 MeV

    Science.gov (United States)

    Gosling, J. T.; Asbridge, J. R.; Bame, S. J.; Feldman, W. C.; Zwickl, R. D.; Paschmann, G.; Sckopke, N.; Hynds, R. J.

    1981-01-01

    An ion velocity distribution function of the postshock phase of an energetic storm particle (ESP) event is obtained from data from the ISEE 2 and ISEE 3 experiments. The distribution function is roughly isotropic in the solar wind frame from solar wind thermal energies to 1.6 MeV. The ESP event studied (8/27/78) is superposed upon a more energetic particle event which was predominantly field-aligned and which was probably of solar origin. The observations suggest that the ESP population is accelerated directly out of the solar wind thermal population or its quiescent suprathermal tail by a stochastic process associated with shock wave disturbance. The acceleration mechanism is sufficiently efficient so that approximately 1% of the solar wind population is accelerated to suprathermal energies. These suprathermal particles have an energy density of approximately 290 eV cubic centimeters.

  14. A Regional GPS Receiver Network For Monitoring Mid-latitude Total Electron Content During Storms

    Science.gov (United States)

    Vernon, A.; Cander, Lj. R.

    A regional GPS receiver network has been used for monitoring mid-latitude total elec- tron content (TEC) during ionospheric storms at the current solar maximum. Differ- ent individual storms were examined to study how the temporal patterns of changes develop and how they are related to solar and geomagnetic activity for parameter de- scriptive of plasmaspheric-ionospheric ionisation. Use is then made of computer con- touring techniques to produce snapshot maps of TEC for different study cases. Com- parisons with the local ionosonde data at different phases of the storms enable the storm developments to be studied in detail.

  15. AI techniques in geomagnetic storm forecasting

    Science.gov (United States)

    Lundstedt, Henrik

    This review deals with how geomagnetic storms can be predicted with the use of Artificial Intelligence (AI) techniques. Today many different Al techniques have been developed, such as symbolic systems (expert and fuzzy systems) and connectionism systems (neural networks). Even integrations of AI techniques exist, so called Intelligent Hybrid Systems (IHS). These systems are capable of learning the mathematical functions underlying the operation of non-linear dynamic systems and also to explain the knowledge they have learned. Very few such powerful systems exist at present. Two such examples are the Magnetospheric Specification Forecast Model of Rice University and the Lund Space Weather Model of Lund University. Various attempts to predict geomagnetic storms on long to short-term are reviewed in this article. Predictions of a month to days ahead most often use solar data as input. The first SOHO data are now available. Due to the high temporal and spatial resolution new solar physics have been revealed. These SOHO data might lead to a breakthrough in these predictions. Predictions hours ahead and shorter rely on real-time solar wind data. WIND gives us real-time data for only part of the day. However, with the launch of the ACE spacecraft in 1997, real-time data during 24 hours will be available. That might lead to the second breakthrough for predictions of geomagnetic storms.

  16. Solar Variability and Planetary Climates

    CERN Document Server

    Calisesi, Y; Gray, L; Langen, J; Lockwood, M

    2007-01-01

    Variations in solar activity, as revealed by variations in the number of sunspots, have been observed since ancient times. To what extent changes in the solar output may affect planetary climates, though, remains today more than ever a subject of controversy. In 2000, the SSSI volume on Solar Variability and Climate reviewed the to-date understanding of the physics of solar variability and of the associated climate response. The present volume on Solar Variability and Planetary Climates provides an overview of recent advances in this field, with particular focus at the Earth's middle and lower atmosphere. The book structure mirrors that of the ISSI workshop held in Bern in June 2005, the collection of invited workshop contributions and of complementary introductory papers synthesizing the current understanding in key research areas such as middle atmospheric processes, stratosphere-troposphere dynamical coupling, tropospheric aerosols chemistry, solar storm influences, solar variability physics, and terrestri...

  17. High-Latitude Topside Ionospheric Vertical Electron-Density-Profile Changes in Response to Large Magnetic Storms

    Science.gov (United States)

    Benson, Robert F.; Fainberg, Joseph; Osherovich, Vladimir A.; Truhlik, Vladimir; Wang, Yongli; Bilitza, Dieter; Fung, Shing F.

    2015-01-01

    Large magnetic-storm induced changes have been detected in high-latitude topside vertical electron-density profiles Ne(h). The investigation was based on the large database of topside Ne(h) profiles and digital topside ionograms from the International Satellites for Ionospheric Studies (ISIS) program available from the NASA Space Physics Data Facility (SPDF) at http://spdf.gsfc.nasa.gov/isis/isis-status.html. This large database enabled Ne(h) profiles to be obtained when an ISIS satellite passed through nearly the same region of space before, during, and after a major magnetic storm. A major goal was to relate the magnetic-storm induced high-latitude Ne(h) profile changes to solar-wind parameters. Thus an additional data constraint was to consider only storms where solar-wind data were available from the NASA/SPDF OMNIWeb database. Ten large magnetic storms (with Dst less than -100 nT) were identified that satisfied both the Ne(h) profile and the solar-wind data constraints. During five of these storms topside ionospheric Ne(h) profiles were available in the high-latitude northern hemisphere and during the other five storms similar ionospheric data were available in the southern hemisphere. Large Ne(h) changes were observed during each one of these storms. Our concentration in this paper is on the northern hemisphere. The data coverage was best for the northern-hemisphere winter. Here Ne(h) profile enhancements were always observed when the magnetic local time (MLT) was between 00 and 03 and Ne(h) profile depletions were always observed between 08 and 10 MLT. The observed Ne(h) deviations were compared with solar-wind parameters, with appropriate time shifts, for four storms.

  18. Lower thermosphere (80-100 km) dynamics response to solar and geomagnetic activity: Overview

    International Nuclear Information System (INIS)

    Kazimirovsky, E.S.

    1989-01-01

    The variations of solar and geomagnetic activity may affect the thermosphere circulation via plasma heating and electric fields, especially at high latitudes. The possibility exists that the energy involved in auroral and magnetic storms can produce significant changes of mesosphere and lower thermosphere wind systems. A study of global radar measurements of winds at 80 to 100 km region revealed the short term effects (correlation between wind field and geomagnetic storms) and long term variations over a solar cycle. It seems likely that the correlation results from a modification of planetary waves and tides propagated from below, thus altering the dynamical regime of the thermosphere. Sometimes the long term behavior points rather to a climatic variation with the internal atmospheric cause than to a direct solar control

  19. Solar Physics at Evergreen: Solar Dynamo and Chromospheric MHD

    Science.gov (United States)

    Zita, E. J.; Maxwell, J.; Song, N.; Dikpati, M.

    2006-12-01

    We describe our five year old solar physics research program at The Evergreen State College. Famed for its cloudy skies, the Pacific Northwest is an ideal location for theoretical and remote solar physics research activities. Why does the Sun's magnetic field flip polarity every 11 years or so? How does this contribute to the magnetic storms Earth experiences when the Sun's field reverses? Why is the temperature in the Sun's upper atmosphere millions of degrees higher than the Sun's surface temperature? How do magnetic waves transport energy in the Sun’s chromosphere and the Earth’s atmosphere? How does solar variability affect climate change? Faculty and undergraduates investigate questions such as these in collaboration with the High Altitude Observatory (HAO) at the National Center for Atmospheric Research (NCAR) in Boulder. We will describe successful student research projects, logistics of remote computing, and our current physics investigations into (1) the solar dynamo and (2) chromospheric magnetohydrodynamics.

  20. Magnetic storm generation by large-scale complex structure Sheath/ICME

    Science.gov (United States)

    Grigorenko, E. E.; Yermolaev, Y. I.; Lodkina, I. G.; Yermolaev, M. Y.; Riazantseva, M.; Borodkova, N. L.

    2017-12-01

    We study temporal profiles of interplanetary plasma and magnetic field parameters as well as magnetospheric indices. We use our catalog of large-scale solar wind phenomena for 1976-2000 interval (see the catalog for 1976-2016 in web-side ftp://ftp.iki.rssi.ru/pub/omni/ prepared on basis of OMNI database (Yermolaev et al., 2009)) and the double superposed epoch analysis method (Yermolaev et al., 2010). Our analysis showed (Yermolaev et al., 2015) that average profiles of Dst and Dst* indices decrease in Sheath interval (magnetic storm activity increases) and increase in ICME interval. This profile coincides with inverted distribution of storm numbers in both intervals (Yermolaev et al., 2017). This behavior is explained by following reasons. (1) IMF magnitude in Sheath is higher than in Ejecta and closed to value in MC. (2) Sheath has 1.5 higher efficiency of storm generation than ICME (Nikolaeva et al., 2015). The most part of so-called CME-induced storms are really Sheath-induced storms and this fact should be taken into account during Space Weather prediction. The work was in part supported by the Russian Science Foundation, grant 16-12-10062. References. 1. Nikolaeva N.S., Y. I. Yermolaev and I. G. Lodkina (2015), Modeling of the corrected Dst* index temporal profile on the main phase of the magnetic storms generated by different types of solar wind, Cosmic Res., 53(2), 119-127 2. Yermolaev Yu. I., N. S. Nikolaeva, I. G. Lodkina and M. Yu. Yermolaev (2009), Catalog of Large-Scale Solar Wind Phenomena during 1976-2000, Cosmic Res., , 47(2), 81-94 3. Yermolaev, Y. I., N. S. Nikolaeva, I. G. Lodkina, and M. Y. Yermolaev (2010), Specific interplanetary conditions for CIR-induced, Sheath-induced, and ICME-induced geomagnetic storms obtained by double superposed epoch analysis, Ann. Geophys., 28, 2177-2186 4. Yermolaev Yu. I., I. G. Lodkina, N. S. Nikolaeva and M. Yu. Yermolaev (2015), Dynamics of large-scale solar wind streams obtained by the double superposed epoch

  1. Local time and cutoff rigidity dependences of storm time increase associated with geomagnetic storms

    International Nuclear Information System (INIS)

    Kudo, S.; Wada, M.; Tanskanen, P.; Kodama, M.

    1987-01-01

    The cosmic ray increases due to considerable depressions of cosmic ray cutoff rigidity during large geomagnetic storms are investigated. Data from a worldwide network of cosmic ray neutron monitors are analyzed for 17 geomagnetic storms which occurred in the quiet phase of the solar activity cycle during 1966-1978. As expected from the longitudinal asymmetry of the low-altitude geomagnetic field during large geomagnetic storms, a significant local time dependence of the increment in the cosmic ray during large geomagnetic storms, a significant local time dependence of the increment in the cosmic ray intensity is obtained. It is shown that the maximum phases of the local time dependence occur at around 1800 LT and that the amplitudes of the local time dependence are consistent with presently available theoretical estimates. The dependence of the increment on the cutoff rigidity is obtained for both the local time dependent part and the local time independent part of the storm time increase. The local time independent part, excluding the randomizing local time dependent part, shows a clear-cut dependence on cutoff rigidity which is consistent with theoretical estimates

  2. Solar radio continuum storms and a breathing magnetic field model. Final report

    International Nuclear Information System (INIS)

    1975-01-01

    Radio noise continuum emissions observed in metric and decametric wave frequencies are, in general, associated with actively varying sunspot groups accompanied by the S-component of microwave radio emissions. These continuum emission sources, often called type I storm sources, are often associated with type III burst storm activity from metric to hectometric wave frequencies. This storm activity is, therefore, closely connected with the development of these continuum emission sources. It is shown that the S-component emission in microwave frequencies generally precedes, by several days, the emission of these noise continuum storms of lower frequencies. In order for these storms to develop, the growth of sunspot groups into complex types is very important in addition to the increase of the average magnetic field intensity and area of these groups. After giving a review on the theory of these noise continuum storm emissions, a model is briefly considered to explain the relation of the emissions to the storms

  3. STATISTICAL STUDY OF STRONG AND EXTREME GEOMAGNETIC DISTURBANCES AND SOLAR CYCLE CHARACTERISTICS

    International Nuclear Information System (INIS)

    Kilpua, E. K. J.; Olspert, N.; Grigorievskiy, A.; Käpylä, M. J.; Tanskanen, E. I.; Pelt, J.; Miyahara, H.; Kataoka, R.; Liu, Y. D.

    2015-01-01

    We study the relation between strong and extreme geomagnetic storms and solar cycle characteristics. The analysis uses an extensive geomagnetic index AA data set spanning over 150 yr complemented by the Kakioka magnetometer recordings. We apply Pearson correlation statistics and estimate the significance of the correlation with a bootstrapping technique. We show that the correlation between the storm occurrence and the strength of the solar cycle decreases from a clear positive correlation with increasing storm magnitude toward a negligible relationship. Hence, the quieter Sun can also launch superstorms that may lead to significant societal and economic impact. Our results show that while weaker storms occur most frequently in the declining phase, the stronger storms have the tendency to occur near solar maximum. Our analysis suggests that the most extreme solar eruptions do not have a direct connection between the solar large-scale dynamo-generated magnetic field, but are rather associated with smaller-scale dynamo and resulting turbulent magnetic fields. The phase distributions of sunspots and storms becoming increasingly in phase with increasing storm strength, on the other hand, may indicate that the extreme storms are related to the toroidal component of the solar large-scale field

  4. STATISTICAL STUDY OF STRONG AND EXTREME GEOMAGNETIC DISTURBANCES AND SOLAR CYCLE CHARACTERISTICS

    Energy Technology Data Exchange (ETDEWEB)

    Kilpua, E. K. J. [Department of Physics, University Helsinki (Finland); Olspert, N.; Grigorievskiy, A.; Käpylä, M. J.; Tanskanen, E. I.; Pelt, J. [ReSoLVE Centre of Excellence, Department of Computer Science, P.O. Box 15400, FI-00076 Aalto Univeristy (Finland); Miyahara, H. [Musashino Art University, 1-736 Ogawa-cho, Kodaira-shi, Tokyo 187-8505 (Japan); Kataoka, R. [National Institute of Polar Research, 10-3 Midori-cho, Tachikawa, Tokyo 190-8518 (Japan); Liu, Y. D. [State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190 (China)

    2015-06-20

    We study the relation between strong and extreme geomagnetic storms and solar cycle characteristics. The analysis uses an extensive geomagnetic index AA data set spanning over 150 yr complemented by the Kakioka magnetometer recordings. We apply Pearson correlation statistics and estimate the significance of the correlation with a bootstrapping technique. We show that the correlation between the storm occurrence and the strength of the solar cycle decreases from a clear positive correlation with increasing storm magnitude toward a negligible relationship. Hence, the quieter Sun can also launch superstorms that may lead to significant societal and economic impact. Our results show that while weaker storms occur most frequently in the declining phase, the stronger storms have the tendency to occur near solar maximum. Our analysis suggests that the most extreme solar eruptions do not have a direct connection between the solar large-scale dynamo-generated magnetic field, but are rather associated with smaller-scale dynamo and resulting turbulent magnetic fields. The phase distributions of sunspots and storms becoming increasingly in phase with increasing storm strength, on the other hand, may indicate that the extreme storms are related to the toroidal component of the solar large-scale field.

  5. Energetic electron precipitation in weak to moderate corotating interaction region-driven storms

    Science.gov (United States)

    Ødegaard, Linn-Kristine Glesnes; Tyssøy, Hilde Nesse; Søraas, Finn; Stadsnes, Johan; Sandanger, Marit Irene

    2017-03-01

    High-energy electron precipitation from the radiation belts can penetrate deep into the mesosphere and increase the production rate of NOx and HOx, which in turn will reduce ozone in catalytic processes. The mechanisms for acceleration and loss of electrons in the radiation belts are not fully understood, and most of the measurements of the precipitating flux into the atmosphere have been insufficient for estimating the loss cone flux. In the present study the electron flux measured by the NOAA POES Medium Energy Proton and Electron Detectors 0° and 90° detectors is combined together with theory of pitch angle diffusion by wave-particle interaction to quantify the electron flux lost below 120 km altitude. Using this method, 41 weak and moderate geomagnetic storms caused by corotating interaction regions during 2006-2010 are studied. The dependence of the energetic electron precipitation fluxes upon solar wind parameters and geomagnetic indices is investigated. Nine storms give increased precipitation of >˜750 keV electrons. Nineteen storms increase the precipitation of >˜300 keV electrons, but not the >˜750 keV population. Thirteen storms either do not change or deplete the fluxes at those energies. Storms that have an increase in the flux of electrons with energy >˜300 keV are characterized by an elevated solar wind velocity for a longer period compared to the storms that do not. Storms with increased precipitation of >˜750 keV flux are distinguished by higher-energy input from the solar wind quantified by the ɛ parameter and corresponding higher geomagnetic activity.

  6. Importance of post-shock streams and sheath region as drivers of intense magnetospheric storms and high-latitude activity

    Directory of Open Access Journals (Sweden)

    K. E. J. Huttunen

    2004-04-01

    Full Text Available Magnetic disturbances in the Earth's magnetosphere can be very different depending on the type of solar wind driver. We have determined the solar wind causes for intense magnetic storms (DstDst index was more difficult to model for a sheath region or a post-shock stream driven storm than for a storm caused by a magnetic cloud.

  7. Prediciting Solar Activity: Today, Tomorrow, Next Year

    Science.gov (United States)

    Pesnell, William Dean

    2008-01-01

    Fleets of satellites circle the Earth collecting science data, protecting astronauts, and relaying information. All of these satellites are sensitive at some level to space weather effects. Predictions of drag on LEO spacecraft are one of the most important. Launching a satellite with less fuel can mean a higher orbit, but unanticipated solar activity and increased drag can make that a Pyrrhic victory. Energetic events at the Sun can produce crippling radiation storms. Predicting those events that will affect our assets in space includes a solar prediction and how the radiation will propagate through the solar system. I will talk our need for solar activity predictions and anticipate how those predictions could be made more accurate in the future.

  8. NOAA Satellites Provide a Keen View of the Martin Luther King Solar Storm of January 2005

    Science.gov (United States)

    Wilkinson, D. C.; Allen, J. H.

    2005-05-01

    Solar active region 0720 rotated onto the east limb on January 10th and put on a pyrotechnic display uncharacteristic for this phase of the solar cycle before disappearing beyond the west limb on January 23rd. On January 15th this region released the first of five X-class solar flares. The last of those flares, January 20th, was associated with an extraordinary ion storm whose effect reached Earth's surface. This paper highlights the record of this event made by NOAA's GOES satellites via their Space Environment Monitor (SEM) subsystems that measures X-ray, energetic particles, and the magnetic field vector at the satellite. Displays of those data are supplemented by neutron monitor data to illustrate their relationship to the January 20th Ground Level Event. GOES-12 is also equipped with the Solar X-ray Imager (SXI) that produces an image of the Sun in X-ray wavelengths once per minute. Movies created from those data perfectly illustrate the cause-and-effect relationship between intense solar activity and satellite disruptions. The flares on January 17th and 20th are closely followed by noise in the SXI telescope resulting from energetic ions penetrating SXI. Ions with sufficient velocity and atomic number can penetrate satellite components and deposit charge along their path. Sufficient charge deposition can introduce erroneous information into solid-state devices. A survey of satellites that experienced problems of this type during this event will also be presented.

  9. Possible mechanism of solar noise storm generation in meter wavelength

    International Nuclear Information System (INIS)

    Genkin, L.G.; Erukhimov, L.M.; Levin, B.N.

    1989-01-01

    Fluctuation plasma mechanism of noise storm generation is proposed. The sporadic formation of density irregularities in plasma (Langmuir) turbulence region is shown to be the result of thermal stratification of plasma. The noise storm type 1 bursts in their typical parameters are like radio emission due to plasma turbulence conversion on this structures

  10. Acceleration and loss of relativistic electrons during small geomagnetic storms.

    Science.gov (United States)

    Anderson, B R; Millan, R M; Reeves, G D; Friedel, R H W

    2015-12-16

    Past studies of radiation belt relativistic electrons have favored active storm time periods, while the effects of small geomagnetic storms ( D s t  > -50 nT) have not been statistically characterized. In this timely study, given the current weak solar cycle, we identify 342 small storms from 1989 through 2000 and quantify the corresponding change in relativistic electron flux at geosynchronous orbit. Surprisingly, small storms can be equally as effective as large storms at enhancing and depleting fluxes. Slight differences exist, as small storms are 10% less likely to result in flux enhancement and 10% more likely to result in flux depletion than large storms. Nevertheless, it is clear that neither acceleration nor loss mechanisms scale with storm drivers as would be expected. Small geomagnetic storms play a significant role in radiation belt relativistic electron dynamics and provide opportunities to gain new insights into the complex balance of acceleration and loss processes.

  11. Dynamics of long-period irregular pulsations in high latitudes during strong magnetic storms

    International Nuclear Information System (INIS)

    Kurazhkovskaya, N.A.; Klajn, B.I.

    1995-01-01

    Effects of strong magnetic storms within np type high-latitudinal long-period irregular pulsations at Mirny studied using data obtained at observatory of the magnetosphere south hemisphere. Variation of long-period irregular pulsation amplitude is shown to depend essentially on duration of storm initial phase and on the nature of solar wind heterogeneity enabling growth of strong storm. 14 refs

  12. Geomagnetic storms

    International Nuclear Information System (INIS)

    McNamara, A.G.

    1980-01-01

    Disturbances due to geomagnetic storms can affect the functioning of communications satellites and of power lines and other long conductors. Two general classes of geomagnetic activity can be distinguished: ionospheric current flow (the auroral electrojet), and magnetospheric compression. Super magnetic storms, such as the one of August 1972, can occur at any time and average about 17 occurrences per century. Electrical transmission systems can be made more tolerant of such events at a price, but the most effective way to minimize damage is by better operator training coupled with effective early warning systems. (LL)

  13. Solar cycle distribution of strong solar proton events and the related solar-terrestrial phenomena

    Science.gov (United States)

    Le, Guiming; Yang, Xingxing; Ding, Liuguang; Liu, Yonghua; Lu, Yangping; Chen, Minhao

    2014-08-01

    We investigated the solar cycle distribution of strong solar proton events (SPEs, peak flux ≥1000 pfu) and the solar-terrestrial phenomena associated with the strong SPEs during solar cycles 21-23. The results show that 37 strong SPEs were registered over this period of time, where 20 strong SPEs were originated from the super active regions (SARs) and 28 strong SPEs were accompanied by the X-class flares. Most strong SPEs were not associated with the ground level enhancement (GLE) event. Most strong SPEs occurred in the descending phases of the solar cycles. The weaker the solar cycle, the higher the proportion of strong SPES occurred in the descending phase of the cycle. The number of the strong SPEs that occurred within a solar cycle is poorly associated with the solar cycle size. The intensity of the SPEs is highly dependent of the location of their source regions, with the super SPEs (≥20000 pfu) distributed around solar disk center. A super SPE was always accompanied by a fast shock driven by the associated coronal mass ejection and a great geomagnetic storm. The source location of strongest GLE event is distributed in the well-connected region. The SPEs associated with super GLE events (peak increase rate ≥100%) which have their peak flux much lower than 10000 pfu were not accompanied by an intense geomagnetic storm.

  14. Effect of solar and magnetic activity on VHF scintillations near the equatorial anomaly crest

    Directory of Open Access Journals (Sweden)

    R. P. Singh

    2004-09-01

    Full Text Available The VHF amplitude scintillation recorded during the period January 1991 to December 1993 in the declining phase of a solar cycle and April 1998 to December 1999 in the ascending phase of the next solar cycle at Varanasi (geogr. lat.=25.3°, long.=83.0°, dip=37°N have been analyzed to study the behavior of ionospheric irregularities during active solar periods and magnetic storms. It is shown that irregularities occur at arbitrary times and may last for <30min. A rise in solar activity increases scintillations during winter (November-February and near equinoxes (March-April; September-October, whereas it depresses the scintillations during the summer (May-July. In general, the role of magnetic activity is to suppress scintillations in the pre-midnight period and to increase it in the post-midnight period during equinox and winter seasons, whilst during summer months the effect is reversed. The pre-midnight scintillation is sometimes observed when the main phase of Dst corresponds to the pre-midnight period. The annual variation shows suppression of scintillations on disturbed days, both during pre-midnight and post-midnight period, which becomes more effective during years of high solar activity. It is observed that for magnetic storms for which the recovery phase starts post-midnight, the probability of occurrence of irregularities is enhanced during this time. If the magnetic storm occurred during daytime, then the probability of occurrence of scintillations during the night hours is decreased. The penetration of magnetospheric electric fields to the magnetic equator affects the evolution of low-latitude irregularities. A delayed disturbance dynamo electric field also affects the development of irregularities.

  15. Seasonal timing of first rain storms affects rare plant population dynamics

    Science.gov (United States)

    Levine, J.M.; McEachern, A.K.; Cowan, C.

    2011-01-01

    A major challenge in forecasting the ecological consequences of climate change is understanding the relative importance of changes to mean conditions vs. changes to discrete climatic events, such as storms, frosts, or droughts. Here we show that the first major storm of the growing season strongly influences the population dynamics of three rare and endangered annual plant species in a coastal California (USA) ecosystem. In a field experiment we used moisture barriers and water addition to manipulate the timing and temperature associated with first major rains of the season. The three focal species showed two- to fivefold variation in per capita population growth rates between the different storm treatments, comparable to variation found in a prior experiment imposing eightfold differences in season-long precipitation. Variation in germination was a major demographic driver of how two of three species responded to the first rains. For one of these species, the timing of the storm was the most critical determinant of its germination, while the other showed enhanced germination with colder storm temperatures. The role of temperature was further supported by laboratory trials showing enhanced germination in cooler treatments. Our work suggests that, because of species-specific cues for demographic transitions such as germination, changes to discrete climate events may be as, if not more, important than changes to season-long variables.

  16. Solar radiophysics

    International Nuclear Information System (INIS)

    McLean, D.J.; Labrum, N.R.

    1985-01-01

    This book treats all aspects of solar radioastronomy at metre wavelengths, particularly work carried out on the Australian radioheliograph at Culgoora, with which most of the authors have been associated in one way or another. After an introductory section on historical aspects, the solar atmosphere, solar flares, and coronal radio emission, the book deals with instrumentation, theory, and details of observations and interpretations of the various aspects of metrewave solar radioastronomy, including burst types, solar storms, and the quiet sun. (U.K.)

  17. High-Latitude Topside Ionospheric Vertical Electron Density Profile Changes in Response to Large Magnetic Storms

    Science.gov (United States)

    Benson, Robert F.; Fainberg, Joseph; Osherovich, Vladimir A.; Truhlik, Vladimir; Wang, Yongli; Bilitza, Dieter; Fung, Shing F.

    2016-01-01

    Large magnetic-storm-induced changes were detected in high-latitude topside vertical electron density profiles Ne(h) in a database of profiles and digital topside ionograms, from the International Satellites for Ionospheric Studies (ISIS) program, that enabled Ne(h) profiles to be obtained in nearly the same region of space before, during, and after a major magnetic storm (Dst -100nT). Storms where Ne(h) profiles were available in the high-latitude Northern Hemisphere had better coverage of solar wind parameters than storms with available Ne(h) profiles in the high-latitude Southern Hemisphere. Large Ne(h) changes were observed during all storms, with enhancements and depletions sometimes near a factor of 10 and 0.1, respectively, but with substantial differences in the responses in the two hemispheres. Large spatial andor temporal Ne(h) changes were often observed during Dst minimum and during the storm recovery phase. The storm-induced Ne(h) changes were the most pronounced and consistent in the Northern Hemisphere in that large enhancements were observed during winter nighttime and large depletions during winter and spring daytime. The limited available cases suggested that these Northern Hemisphere enhancements increased with increases of the time-shifted solar wind velocity v, magnetic field B, and with more negative values of the B components except for the highest common altitude (1100km) of the profiles. There was also some evidence suggesting that the Northern Hemisphere depletions were related to changes in the solar wind parameters. Southern Hemisphere storm-induced enhancements and depletions were typically considerably less with depletions observed during summer nighttime conditions and enhancements during summer daytime and fall nighttime conditions.

  18. Role of neutral wind and storm time electric fields inferred from the storm time ionization distribution at low latitudes: in-situ measurements by Indian satellite SROSS-C2

    Directory of Open Access Journals (Sweden)

    P. Subrahmanyam

    2005-11-01

    Full Text Available Recently, there has been a renewal of interest in the study of the effects of solar weather events on the ionization redistribution and irregularity generation. The observed changes at low and equatorial latitudes are rather complex and are noted to be a function of location, the time of the storm onset and its intensity, and various other characteristics of the geomagnetic storms triggered by solar weather events. At these latitudes, the effects of geomagnetic storms are basically due to (a direct penetration of the magnetospheric electric fields to low latitudes, (b development of disturbance dynamo, (c changes in atmospheric neutral winds at ionospheric level and (d changes in neutral composition triggered by the storm time atmospheric heating.

    In the present study an attempt is made to further understand some of the observed storm time effects in terms of storm time changes in zonal electric fields and meridional neutral winds. For this purpose, observations made by the Retarding Potential Analyzer (RPA payload on board the Indian satellite SROSS-C2 are examined for four prominent geomagnetic storm events that occurred during the high solar activity period of 1997-2000. Available simultaneous observations, from the GPS satellite network, are also used. The daytime passes of SROSS-C2 have been selected to examine the redistribution of ionization in the equatorial ionization anomaly (EIA region. In general, EIA is observed to be weakened 12-24 h after the main phase onset (MPO of the storm. The storm time behaviour inferred by SROSS-C2 and the GPS satellite network during the geomagnetic storm of 13 November 1998, for which simultaneous observations are available, is found to be consistent. Storm time changes in the delay of received GPS signals are noted to be ~1-3 m, which is a significant component of the total delay observed on a quiet day.

    An attempt is made to identify and

  19. The postsunset vertical plasma drift during geomagnetic storms and its effects on the generation of equatorial spread F

    Science.gov (United States)

    Huang, C.

    2017-12-01

    We will present two distinct phenomena related to the postsunset vertical plasma drift and equatorial spread F (ESF) observed by the Communication/Navigation Outage Forecasting System satellite over six years. The first phenomenon is the behavior of the prereversal enhancement (PRE) of the vertical plasma drift during geomagnetic storms. Statistically, storm-time disturbance dynamo electric fields cause the PRE to decrease from 30 to 0 m/s when Dst changes from -60 to -100 nT, but the PRE does not show obvious variations when Dst varies from 0 to -60 nT. The observations show that the storm activities affect the evening equatorial ionosphere only for Dst correlated with the PRE and that the occurrence of small-amplitude ESF irregularities does not show a clear pattern at low solar activity but is anti-correlated with large-amplitude irregularities and the PRE at moderate solar activity. That is, the months and longitudes with high occurrence probability of large-amplitude irregularities are exactly those with low occurrence probability of small-amplitude irregularities, and vice versa. The generation of large-amplitude ESF irregularities is controlled by the PRE, and the generation of small-amplitude ESF irregularities may be caused by gravity waves and other disturbances, rather than by the PRE.

  20. Investigating Changes in the High-Latitude Topside Ionosphere During Large Magnetic Storms

    Science.gov (United States)

    Fainberg, Joseph; Benson, Robert F.; Osherovich, Vladimir; Truhlik, Vladimir; Wang, Yongli; Fung, Shing; Bilitza, Dieter

    2009-01-01

    A search was conducted to locate periods of nearly simultaneous solar-wind and high latitude topside-ionospheric data during magnetic storms. The focus was on the 20-yr interval from 1965 to 1985 when both solar-wind and Alouette/ISIS topside-sounder data are potentially available. The search yielded 125 large magnetic storms (minimum Dst less than 100) and 280 moderate magnetic storms (minimum Dst between -60 and -100). Solar wind data were available for most, but not all, of these storms. A search of the available high-latitude topside electron-density Ne(h) profiles available from the National Space Science Data Center (NSSDC), both from manual inspection of 35-mm film ionograms in the 1960s and more recent auto-processing of ISIS-2 topside digital ionograms using the TOPIST software, during 9-day intervals associated with the 125 large magnetic storm minimum Dst times yielded the following results: 31 intervals had 10 or more manual-scaled profiles (21 intervals had more than 100 profiles and 5 of these had more than 1,000 profiles), and 34 intervals had 10 or more TOPIST profiles (2 intervals had more than 100 profiles). In addition, a search of the available Alouette-2, ISIS-1 and ISIS-2 digital ionograms during the above periods has yielded encouraging initial results in that many ISIS-1 ionograms were found for the early time intervals. Future work will include the search for 35-mm film ionograms during selected intervals. This presentation will illustrate the results of this investigation to date.

  1. Space Weather: The Solar Perspective

    Directory of Open Access Journals (Sweden)

    Schwenn Rainer

    2006-08-01

    Full Text Available The term space weather refers to conditions on the Sun and in the solar wind, magnetosphere, ionosphere, and thermosphere that can influence the performance and reliability of space-borne and ground-based technological systems and that can affect human life and health. Our modern hi-tech society has become increasingly vulnerable to disturbances from outside the Earth system, in particular to those initiated by explosive events on the Sun: Flares release flashes of radiation that can heat up the terrestrial atmosphere such that satellites are slowed down and drop into lower orbits, solar energetic particles accelerated to near-relativistic energies may endanger astronauts traveling through interplanetary space, and coronal mass ejections are gigantic clouds of ionized gas ejected into interplanetary space that after a few hours or days may hit the Earth and cause geomagnetic storms. In this review, I describe the several chains of actions originating in our parent star, the Sun, that affect Earth, with particular attention to the solar phenomena and the subsequent effects in interplanetary space.

  2. Space Weather: The Solar Perspective

    Science.gov (United States)

    Schwenn, Rainer

    2006-08-01

    The term space weather refers to conditions on the Sun and in the solar wind, magnetosphere, ionosphere, and thermosphere that can influence the performance and reliability of space-borne and ground-based technological systems and that can affect human life and health. Our modern hi-tech society has become increasingly vulnerable to disturbances from outside the Earth system, in particular to those initiated by explosive events on the Sun: Flares release flashes of radiation that can heat up the terrestrial atmosphere such that satellites are slowed down and drop into lower orbits, solar energetic particles accelerated to near-relativistic energies may endanger astronauts traveling through interplanetary space, and coronal mass ejections are gigantic clouds of ionized gas ejected into interplanetary space that after a few hours or days may hit the Earth and cause geomagnetic storms. In this review, I describe the several chains of actions originating in our parent star, the Sun, that affect Earth, with particular attention to the solar phenomena and the subsequent effects in interplanetary space.

  3. Impact of the Icme-Earth Geometry on the Strength of the Associated Geomagnetic Storm: The September 2014 and March 2015 Events

    Science.gov (United States)

    Cho, K.-S.; Marubashi, K.; Kim, R.-S.; Park, S.-H.; Lim, E.-K.; Kim, S.-J.; Kumar, P.; Yurchyshyn, V.; Moon, Y.-J.; Lee, J.-O.

    2017-04-01

    We investigate two abnormal CME-Storm pairs that occurred on 2014 September 10 - 12 and 2015 March 15 - 17, respectively. The first one was a moderate geomagnetic storm (Dst_{min} ˜ -75 nT) driven by the X1.6 high speed flare-associated CME (1267 km s^{-1}) in AR 12158 (N14E02) near solar disk center. The other was a very intense geomagnetic storm (Dst_{min} ˜ -223 nT) caused by a CME with moderate speed (719 km s^{-1}) and associated with a filament eruption accompanied by a weak flare (C9.1) in AR 12297 (S17W38). Both CMEs have large direction parameters facing the Earth and southward magnetic field orientation in their solar source region. In this study, we inspect the structure of Interplanetary Flux Ropes (IFRs) at the Earth estimated by using the torus fitting technique assuming self-similar expansion. As results, we find that the moderate storm on 2014 September 12 was caused by small-scale southward magnetic fields in the sheath region ahead of the IFR. The Earth traversed the portion of the IFR where only the northward fields are observed. Meanwhile, in case of the 2015 March 17 storm, our IFR analysis revealed that the Earth passed the very portion where only the southward magnetic fields are observed throughout the passage. The resultant southward magnetic field with long-duration is the main cause of the intense storm. We suggest that 3D magnetic field geometry of an IFR at the IFR-Earth encounter is important and the strength of a geomagnetic storm is strongly affected by the relative location of the Earth with respect to the IFR structure.

  4. Flight attendant radiation dose from solar particle events.

    Science.gov (United States)

    Anderson, Jeri L; Mertens, Christopher J; Grajewski, Barbara; Luo, Lian; Tseng, Chih-Yu; Cassinelli, Rick T

    2014-08-01

    Research has suggested that work as a flight attendant may be related to increased risk for reproductive health effects. Air cabin exposures that may influence reproductive health include radiation dose from galactic cosmic radiation and solar particle events. This paper describes the assessment of radiation dose accrued during solar particle events as part of a reproductive health study of flight attendants. Solar storm data were obtained from the National Oceanic and Atmospheric Administration Space Weather Prediction Center list of solar proton events affecting the Earth environment to ascertain storms relevant to the two study periods (1992-1996 and 1999-2001). Radiation dose from exposure to solar energetic particles was estimated using the NAIRAS model in conjunction with galactic cosmic radiation dose calculated using the CARI-6P computer program. Seven solar particle events were determined to have potential for significant radiation exposure, two in the first study period and five in the second study period, and over-lapped with 24,807 flight segments. Absorbed (and effective) flight segment doses averaged 6.5 μGy (18 μSv) and 3.1 μGy (8.3 μSv) for the first and second study periods, respectively. Maximum doses were as high as 440 μGy (1.2 mSv) and 20 flight segments had doses greater than 190 μGy (0.5 mSv). During solar particle events, a pregnant flight attendant could potentially exceed the equivalent dose limit to the conceptus of 0.5 mSv in a month recommended by the National Council on Radiation Protection and Measurements.

  5. Elliptical magnetic clouds and geomagnetic storms

    Czech Academy of Sciences Publication Activity Database

    Antoniadou, I.; Geranios, A.; Vandas, Marek; Panagopoulou, M.; Zacharopoulou, O.; Malandraki, O.

    2008-01-01

    Roč. 56, 3-4 (2008), s. 492-500 ISSN 0032-0633 R&D Projects: GA AV ČR 1QS300120506; GA ČR GA205/06/0875 Institutional research plan: CEZ:AV0Z10030501 Keywords : magnetic clouds * geomagnetic storms * solar wind Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 2.506, year: 2008

  6. Manifestation of interplanetary medium parameters in development of a geomagnetic storm initial phase

    International Nuclear Information System (INIS)

    Chkhetiya, A.M.

    1988-01-01

    The role of solar wind plasma parameters in formation of a geomagnetic storm initial phase is refined. On the basis of statistical analysis an empirical formula relating the interplanetary medium parameters (components of interplanetary magnetic field, proton velocity and concentration) and D st -index during the geomagnetic storm initial phase is proposed

  7. Positive and negative ionospheric storms occurring during the 15 May 2005 geomagnetic superstorm

    Science.gov (United States)

    Horvath, Ildiko; Lovell, Brian C.

    2015-09-01

    This study focuses on the 15 May 2005 geomagnetic superstorm and aims to investigate the global variation of positive and negative storm phases and their development. Observations are provided by a series of global total electron content maps and multi-instrument line plots. Coupled Thermosphere-Ionosphere-Plasmasphere electrodynamics (CTIPe) simulations are also employed. Results reveal some sunward streaming plumes of storm-enhanced density (SED) over Asia and a well-developed midlatitude trough over North America forming isolated positive and negative storms, respectively. The simultaneous development of positive and negative storms over North America is also shown. Then, some enhanced auroral ionizations maintained by strong equatorward neutral winds appeared in the depleted nighttime ionosphere. Meanwhile, the northern nighttime polar region became significantly depleted as the SED plume plasma could not progress further than the dayside cusp. Oppositely, a polar tongue of ionization (TOI) developed in the daytime southern polar region. According to CTIP simulations, solar heating locally maximized (minimized) over the southern (northern) magnetic pole. Furthermore, strong upward surges of molecular-rich air created O/N2 decreases both in the auroral zone and in the trough region, while some SED-related downward surges produced O/N2 increases. From these results we conclude for the time period studied that (1) composition changes contributed to the formation of positive and negative storms, (2) strengthening polar convection and increasing solar heating of the polar cap supported polar TOI development, and (3) a weaker polar convection and minimized solar heating of the polar cap aided the depletion of polar plasma.

  8. Topographic Correction Module at Storm (TC@Storm)

    Science.gov (United States)

    Zaksek, K.; Cotar, K.; Veljanovski, T.; Pehani, P.; Ostir, K.

    2015-04-01

    Different solar position in combination with terrain slope and aspect result in different illumination of inclined surfaces. Therefore, the retrieved satellite data cannot be accurately transformed to the spectral reflectance, which depends only on the land cover. The topographic correction should remove this effect and enable further automatic processing of higher level products. The topographic correction TC@STORM was developed as a module within the SPACE-SI automatic near-real-time image processing chain STORM. It combines physical approach with the standard Minnaert method. The total irradiance is modelled as a three-component irradiance: direct (dependent on incidence angle, sun zenith angle and slope), diffuse from the sky (dependent mainly on sky-view factor), and diffuse reflected from the terrain (dependent on sky-view factor and albedo). For computation of diffuse irradiation from the sky we assume an anisotropic brightness of the sky. We iteratively estimate a linear combination from 10 different models, to provide the best results. Dependent on the data resolution, we mask shades based on radiometric (image) or geometric properties. The method was tested on RapidEye, Landsat 8, and PROBA-V data. Final results of the correction were evaluated and statistically validated based on various topography settings and land cover classes. Images show great improvements in shaded areas.

  9. Identification of possible intense historical geomagnetic storms using combined sunspot and auroral observations from East Asia

    Directory of Open Access Journals (Sweden)

    D. M. Willis

    2005-03-01

    Full Text Available Comprehensive catalogues of ancient sunspot and auroral observations from East Asia are used to identify possible intense historical geomagnetic storms in the interval 210 BC-AD 1918. There are about 270 entries in the sunspot catalogue and about 1150 entries in the auroral catalogue. Special databases have been constructed in which the scientific information in these two catalogues is placed in specified fields. For the purposes of this study, an historical geomagnetic storm is defined in terms of an auroral observation that is apparently associated with a particular sunspot observation, in the sense that the auroral observation occurred within several days of the sunspot observation. More precisely, a selection criterion is formulated for the automatic identification of such geomagnetic storms, using the oriental records stored in the sunspot and auroral databases. The selection criterion is based on specific assumptions about the duration of sunspot visibility with the unaided eye, the likely range of heliographic longitudes of an energetic solar feature, and the likely range of transit times for ejected solar plasma to travel from the Sun to the Earth. This selection criterion results in the identification of nineteen putative historical geomagnetic storms, although two of these storms are spurious in the sense that there are two examples of a single sunspot observation being associated with two different auroral observations separated by more than half a (synodic solar rotation period. The literary and scientific reliabilities of the East Asian sunspot and auroral records that define the nineteen historical geomagnetic storms are discussed in detail in a set of appendices. A possible time sequence of events is presented for each geomagnetic storm, including possible dates for both the central meridian passage of the sunspot and the occurrence of the energetic solar feature, as well as likely transit times for the ejected solar plasma

  10. Fine structure in fast drift storm bursts

    International Nuclear Information System (INIS)

    McConnell, D.; Ellis, G.R.A.

    1981-01-01

    Recent observations with high time resolution of fast drift storm (FDS) solar bursts are described. A new variety of FDS bursts characterised by intensity maxima regularly placed in the frequency domain is reported. Possible interpretations of this are mentioned and the implications of the short duration of FDS bursts are discussed. (orig.)

  11. Statistical Analysis of Solar Events Associated with Storm Sudden Commencements over One Year of Solar Maximum during Cycle 23: Propagation and Effects from the Sun to the Earth.

    Science.gov (United States)

    Bocchialini, K.; Grison, B.; Menvielle, M.; Chambodut, A.; Cornilleau-Wehrlin, N.; Fontaine, D.; Marchaudon, A.; Pick, M.; Pitout, F.; Schmieder, B.; Régnier, S.; Zouganelis, I.

    2017-12-01

    From the list of 32 SSCs over the year 2002, we performed a multi-criteria analysis based on propagation time, velocity comparison, sense of the magnetic field rotation, radio waves to associate them with solar sources, identify their causes in the interplanetary medium and then look at the response of the terrestrial ionized and neutral environment to them. The complex interactions between two (or more) CMEs and the modification in their trajectory have been examined using joint white light and multiple-wavelength radio observations. The structures at L_1 after the 32 SSCs are regarded as Magnetic Clouds (MCs), ICMEs without a MC structure, Miscellaneous structures, CIRs/SIRs, and shock-only events. In terms of geoeffectivity, generally CMEs with velocities at the Sun larger than 1000 km.s-1 have larger probabilities to trigger moderate or intense storms. The most geoeffective events are MCs, since 92% of them trigger moderate or intense storms. The geoeffective events trigger an increased and combined AKR and NTC wave activity in the magnetosphere, an enhanced convection in the ionosphere and a stronger response in the thermosphere.

  12. Solar activity affects avian timing of reproduction

    NARCIS (Netherlands)

    Visser, M.E.; Sanz, J.J.

    2009-01-01

    Avian timing of reproduction is strongly affected by ambient temperature. Here we show that there is an additional effect of sunspots on laying date, from five long-term population studies of great and blue tits (Parus major and Cyanistes caeruleus), demonstrating for the first time that solar

  13. GPS phase scintillation during the geomagnetic storm of March 17, 2015: The relation to auroral electrojet currents

    DEFF Research Database (Denmark)

    Prikryl, Paul; Ghoddousi-Fard, Reza; Connors, Martin

    and magnetometers. GPS phase scintillation index is computed for L1 signal sampled at the rate of 50 Hz by specialized GPS scintillation receivers of the Expanded Canadian High Arctic Ionospheric Network (ECHAIN). To further extend the geographic coverage, the phasescintillation proxy index is obtained from......Ionospheric irregularities cause rapid fluctuations of radio wave amplitude and phase that candegrade GPS positional accuracy and affect performance of radio communication and navigation systems. The ionosphere becomes particularly disturbed during geomagnetic storms caused by impacts of coronal...... mass ejections compounded by high-speed plasma streams from coronal holes. Geomagnetic storm of March 17, 2015 was the largest in the current solar cycle. The high-latitude ionosphere dynamics is studied using arrays of ground-based instruments including GPS receivers, HF radars, ionosondes, riometers...

  14. Geometric effects of ICMEs on geomagnetic storms

    Science.gov (United States)

    Cho, KyungSuk; Lee, Jae-Ok

    2017-04-01

    It has been known that the geomagnetic storm is occurred by the interaction between the Interplanetary Coronal Mass Ejection (ICME) and the Earth's magnetosphere; especially, the southward Bz component of ICME is thought as the main trigger. In this study, we investigate the relationship between Dst index and solar wind conditions; which are the southward Bz, electric field (VBz), and time integral of electric field as well as ICME parameters derived from toroidal fitting model in order to find what is main factor to the geomagnetic storm. We also inspect locations of Earth in ICMEs to understand the geometric effects of the Interplanetary Flux Ropes (IFRs) on the geomagnetic storms. Among 59 CDAW ICME lists, we select 30 IFR events that are available by the toroidal fitting model and classify them into two sub-groups: geomagnetic storms associated with the Magnetic Clouds (MCs) and the compression regions ahead of the MCs (sheath). The main results are as follows: (1) The time integral of electric field has a higher correlation coefficient (cc) with Dst index than the other parameters: cc=0.85 for 25 MC events and cc=0.99 for 5 sheath events. (2) The sheath associated intense storms (Dst ≤-100nT) having usually occur at flank regions of ICMEs while the MC associated intense storms occur regardless of the locations of the Earth in ICMEs. The strength of a geomagnetic storm strongly depends on electric field of IFR and durations of the IFR passages through the Earth.

  15. Magnetospheric storm dynamics in terms of energy output rate

    International Nuclear Information System (INIS)

    Prigancova, A.; Feldstein, Ya.I.

    1992-01-01

    Using hourly values of both the global magnetospheric disturbance characteristic DR, and AE index of auroral ionospheric currents during magnetic storm intervals, the energy output rate dynamics is evaluated for a magnetic storm main/recovery phase and a whole storm interval. The magnetospheric response to the solar wind energy input rate under varying interplanetary and magnetospheric conditions is considered from the temporal variability point of view. The peculiarities of the response are traced separately. As far as quantitative characteristics of energy output rate are concerned, the time dependence pattern of the ring current decay parameter is emphasized to be fairly important. It is pointed out that more insight into the plasma processes, especially at L = 3 - 5, is needed for adequate evidence of the dependence. (Author)

  16. Plasmapause Dynamics Observed During the 17 March and 28 June 2013 Storms

    Science.gov (United States)

    Bishop, R. L.; Coster, A. J.; Turner, D. L.; Nikoukar, R.; Lemon, C.; Roeder, J. L.; Shumko, M.; Bhatt, R.; Payne, C.; Bust, G. S.

    2017-12-01

    Earth's plasmasphere is a region of cold (T ≤ 1 eV), dense (n 101 to 104 cm-3) plasma located in the inner magnetosphere and coincident with a portion of the ionosphere that co-rotates with the planet in the geomagnetic field. Plasmaspheric plasma originates in the ionosphere and fills the magnetic flux tubes on which the corotation electric field dominates over the convection electric field. The corotation electric field results from Earth's spinning magnetic field while the convection electric field results from the solar wind driving of global plasma convection within the magnetosphere. The outer boundary of the plasmasphere is the plasmapause, and it corresponds to the transition region between corotation-driven vs. convection-driven plasmas. When the convection electric field is enhanced during active solar wind periods, such as magnetic storms, the plasmasphere can rapidly erode to L 2.5 or less. During subsequent quiet periods of low solar wind speed and weak interplanetary magnetic field (IMF), ionospheric outflow from lower altitudes refills the plasmasphere over the course of several days or more, with the plasmapause expanding to higher L-shells. The combination of convection, corotation, and ionospheric plasma outflow during and after a storm leads to characteristic features such as plasmaspheric shoulders, notches, and plumes. In this presentation, we focus on the dynamics of the plasmapause during two storms in 2013: March 17 and June 28. The minimum Dst for the two storms were -139 and -98 nT, respectively. We examine plasmapause dynamics utilizing data from an extensive global network of ground-based scientific GPS receivers ( 4000) and line-of-sight observations from the GPS receivers on the COSMIC and C/NOFS satellites, along with data from THEMIS and van Allen Probes, and Millstone Hill Incoherent Scatter Radar. Using the various datasets, we will compare the pre-storm and storm-time plasmasphere. We will also examine the location, evolution

  17. On the possible relations between solar activities and global seismicity in the solar cycle 20 to 23

    Energy Technology Data Exchange (ETDEWEB)

    Herdiwijaya, Dhani, E-mail: dhani@as.itb.ac.id [Astronomy Research Division and Bosscha Observatory, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Ganesha 10, Bandung, Indonesia 40132 (Indonesia); Arif, Johan [Geology Research Division, Faculty of Earth Sciences and Technology, Bandung Institute of Technology, Ganesha 10, Bandung, Indonesia 40132 (Indonesia); Nurzaman, Muhamad Zamzam; Astuti, Isna Kusuma Dewi [Astronomy Study Program, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Ganesha 10, Bandung, Indonesia 40132 (Indonesia)

    2015-09-30

    Solar activities consist of high energetic particle streams, electromagnetic radiation, magnetic and orbital gravitational forces. The well-know solar activity main indicator is the existence of sunspot which has mean variation in 11 years, named by solar cycle, allow for the above fluctuations. Solar activities are also related to the space weather affecting all planetary atmospheric variability, moreover to the Earth’s climate variability. Large extreme space and geophysical events (high magnitude earthquakes, explosive volcanic eruptions, magnetic storms, etc.) are hazards for humankind, infrastructure, economies, technology and the activities of civilization. With a growing world population, and with modern reliance on delicate technological systems, human society is becoming increasingly vulnerable to natural hazardous events. The big question arises to the relation between solar forcing energy to the Earth’s global seismic activities. Estimates are needed for the long term occurrence-rate probabilities of these extreme natural hazardous events. We studied connectivity from yearly seismic activities that refer to and sunspot number within the solar cycle 20 to 23 of year 1960 to 2013 (53 years). We found clear evidences that in general high magnitude earthquake events and their depth were related to the low solar activity.

  18. On the possible relations between solar activities and global seismicity in the solar cycle 20 to 23

    Science.gov (United States)

    Herdiwijaya, Dhani; Arif, Johan; Nurzaman, Muhamad Zamzam; Astuti, Isna Kusuma Dewi

    2015-09-01

    Solar activities consist of high energetic particle streams, electromagnetic radiation, magnetic and orbital gravitational forces. The well-know solar activity main indicator is the existence of sunspot which has mean variation in 11 years, named by solar cycle, allow for the above fluctuations. Solar activities are also related to the space weather affecting all planetary atmospheric variability, moreover to the Earth's climate variability. Large extreme space and geophysical events (high magnitude earthquakes, explosive volcanic eruptions, magnetic storms, etc.) are hazards for humankind, infrastructure, economies, technology and the activities of civilization. With a growing world population, and with modern reliance on delicate technological systems, human society is becoming increasingly vulnerable to natural hazardous events. The big question arises to the relation between solar forcing energy to the Earth's global seismic activities. Estimates are needed for the long term occurrence-rate probabilities of these extreme natural hazardous events. We studied connectivity from yearly seismic activities that refer to and sunspot number within the solar cycle 20 to 23 of year 1960 to 2013 (53 years). We found clear evidences that in general high magnitude earthquake events and their depth were related to the low solar activity.

  19. Magnetic storm effect on the occurrence of ionospheric irregularities at an equatorial station in the African sector

    Directory of Open Access Journals (Sweden)

    Olushola Abel Oladipo

    2014-01-01

    Full Text Available Large-scale ionospheric irregularities usually measured by GPS TEC fluctuation indices are regular occurrence at the equatorial region shortly after sunset around solar maximum. Magnetic storm can trigger or inhibit the generation of these irregularities depending on the local time the main phase of a particular storm occurs. We studied the effect of nine (9 distinct storms on the occurrence of ionospheric irregularities at Fraceville in Gabon (Lat = −1.63˚, Long = 13.55˚, dip lat. = −15.94˚, an equatorial station in the African sector. These storms occurred between November 2001 and September 2002. We used TEC fluctuation indices (i.e. ROTI and ROTIAVE estimated from 30 s interval Rinex data and also we used the storm indices (i.e. Dst, dDst/dt, and IMF BZ to predict the likely effect of each storm on the irregularities occurrence at this station. The results obtained showed that most of the storms studied inhibited ionospheric irregularities. Only one out of all the storms studied (i.e. September 4, 2002 storms with the main phase on the night of September 7-8 triggered post-midnight ionospheric irregularities. There are two of the storms during which ionospheric irregularities were observed. However, these may not be solely attributed to the storms event because the level of irregularities observed during these two storms is comparable to that observed during previous days before the storms. For this station and for the storms investigated, it seems like a little modification to the use of Aarons categories in terms of the local time the maximum negative Dst occurs could lead to a better prediction. However, it would require investigating many storms during different level of solar activities and at different latitudes to generalize this modification.

  20. Mars atmospheric phenomena during major dust storms, as measured at surface

    International Nuclear Information System (INIS)

    Ryan, J.A.; Henry, R.M.

    1979-01-01

    Meteorological instrumentation aboard the Viking Mars Landers measures wind, temperature, and pressure. Two global dust storms occurred during northern autumn and winter, observed both by the orbiters and by the landers. The meteorological data from the landers has been analyzed for the period just before first storm arrival to just after second storm arrival, with the objectives being definition of meteorological phenomena during the storm period, determination of those associated with storm and dust arrival, and evaluation of effects on synoptic conditions and the general circulation. Times of dust arrival over the sites could be defined fairly closely from optical and pressure (solar tide) data, and dust arrival was also accompanied by changes in diurnal temperature range, temperature maxima, and temperature minima. The arrivals of the storms at VL-1 were accompanied by significant increase in wind speed and pressure. No such changes were observed at VL-2. It is possible that surface material could have been raised locally at VL-1. Throughout the period except following the second dust storm synoptic picture at VL-2 was one of eastward moving cyclonic and anticyclonic systems. These disappeared following the second storm, a phenomenon which may be related to the storm

  1. Controlling of merging electric field and IMF magnitude on storm-time changes in thermospheric mass density

    NARCIS (Netherlands)

    Zhou, Y.L.; Ma, S.Y.; Liu, R.S.; Luehr, H.; Doornbos, E.

    2013-01-01

    The controls of merging electrical field, Em, and IMF (interplanetary magnetic field) magnitude, B, on the storm-time changes in upper thermospheric mass density are statistically investigated using GRACE accelerometer observations and the OMNI data of solar wind and IMF for 35 great storms during

  2. Interplanetary ions during an energetic storm particle event: The distribution function from solar wind thermal energies to 1.6 MeV

    International Nuclear Information System (INIS)

    Gosling, J.T.; Asbridge, J.R.; Bame, S.J.; Feldman, W.C.; Zwickl, R.D.; Paschmann, G.; Sckopke, N.; Hynds, R.J.

    1981-01-01

    Data from the Los Alamos Scientific Laboratory/Max-Planck-Institut fast plasma experiment on Isee 2 have been combined with data from the European Space Agency/Imperial College/Space Research Laboratory low-energy proton experiment on Isee 3 to obtain for the first time an ion velocity distribution function f(v) extending from solar wind energies (-1 keV) to 1.6 MeV during the postshock phase of an energetic storm particle (ESP) event. This study reveals that f(v) of the ESP population is roughly isotropic in the solar wind frame from solar wind thermal energies out to 1.6 MeV. Emerging smoothly out of the solar wind thermal distribution, the ESP f(v) initially falls with increasing energy as E/sup -2.4/ in the solar wind frame. Above about 40 keV no single power law exponent adequately describes the energy dependence of f(v) in the solar wind frame. Above approx.200 keV in both the spacecraft frame and the solar wind frame, f(v) can be described by an exponential in speed (f(v)proportionale/sup -v/v//sub o/) with v/sub o/ = 1.05 x 10 8 cm s -1 . The ESP event studied (August 27, 1978) was superposed upon a more energetic particle event which was predominantly field-aligned and which was probably of solar origin. Our observations suggest that the ESP population is accelerated directly out of the solar wind thermal population or its quiescent suprathermal tail by a stochastic process associated with the shock wave disturbance. The acceleration mechanism is sufficiently efficient that approx.1% of the solar wind population is accelerated to suprathermal energies. These suprathermal particles have an energy density of approx.290 eV cm -3

  3. Hydrogen escape from Mars enhanced by deep convection in dust storms

    Science.gov (United States)

    Heavens, Nicholas G.; Kleinböhl, Armin; Chaffin, Michael S.; Halekas, Jasper S.; Kass, David M.; Hayne, Paul O.; McCleese, Daniel J.; Piqueux, Sylvain; Shirley, James H.; Schofield, John T.

    2018-02-01

    Present-day water loss from Mars provides insight into Mars's past habitability1-3. Its main mechanism is thought to be Jeans escape of a steady hydrogen reservoir sourced from odd-oxygen reactions with near-surface water vapour2, 4,5. The observed escape rate, however, is strongly variable and correlates poorly with solar extreme-ultraviolet radiation flux6-8, which was predicted to modulate escape9. This variability has recently been attributed to hydrogen sourced from photolysed middle atmospheric water vapour10, whose vertical and seasonal distribution is only partly characterized and understood11-13. Here, we report multi-annual observational estimates of water content and dust and water transport to the middle atmosphere from Mars Climate Sounder data. We provide strong evidence that the transport of water vapour and ice to the middle atmosphere by deep convection in Martian dust storms can enhance hydrogen escape. Planet-encircling dust storms can raise the effective hygropause (where water content rapidly decreases to effectively zero) from 50 to 80 km above the areoid (the reference equipotential surface). Smaller dust storms contribute to an annual mode in water content at 40-50 km that may explain seasonal variability in escape. Our results imply that Martian atmospheric chemistry and evolution can be strongly affected by the meteorology of the lower and middle atmosphere of Mars.

  4. Storm-time radiation belt electron dynamics: Repeatability in the outer radiation belt

    Science.gov (United States)

    Murphy, K. R.; Mann, I. R.; Rae, J.; Watt, C.; Boyd, A. J.; Turner, D. L.; Claudepierre, S. G.; Baker, D. N.; Spence, H. E.; Reeves, G. D.; Blake, J. B.; Fennell, J. F.

    2017-12-01

    During intervals of enhanced solar wind driving the outer radiation belt becomes extremely dynamic leading to geomagnetic storms. During these storms the flux of energetic electrons can vary by over 4 orders of magnitude. Despite recent advances in understanding the nature of competing storm-time electron loss and acceleration processes the dynamic behavior of the outer radiation belt remains poorly understood; the outer radiation belt can exhibit either no change, an enhancement, or depletion in radiation belt electrons. Using a new analysis of the total radiation belt electron content, calculated from the Van Allen probes phase space density (PSD), we statistically analyze the time-dependent and global response of the outer radiation belt during storms. We demonstrate that by removing adiabatic effects there is a clear and repeatable sequence of events in storm-time radiation belt electron dynamics. Namely, the relativistic (μ=1000 MeV/G) and ultra-relativistic (μ=4000 MeV/G) electron populations can be separated into two phases; an initial phase dominated by loss followed by a second phase dominated by acceleration. At lower energies, the radiation belt seed population of electrons (μ=150 MeV/G) shows no evidence of loss but rather a net enhancement during storms. Further, we investigate the dependence of electron dynamics as a function of the second adiabatic invariant, K. These results demonstrate a global coherency in the dynamics of the source, relativistic and ultra-relativistic electron populations as function of the second adiabatic invariant K. This analysis demonstrates two key aspects of storm-time radiation belt electron dynamics. First, the radiation belt responds repeatably to solar wind driving during geomagnetic storms. Second, the response of the radiation belt is energy dependent, relativistic electrons behaving differently than lower energy seed electrons. These results have important implications in radiation belt research. In particular

  5. Geomagnetic storms and their sources on the sun:the rising phase of the sunspot cycle

    Directory of Open Access Journals (Sweden)

    Takao Saito

    2013-03-01

    Full Text Available Solar phenomena, including solar flares and coronal holes, are considered in the context of a NEWS coordinate system, obtained by application of the heliographic and heliomagnetic coordinate systems to the solar latitude and longitude, respectively. By expressing the occurrence of solar phenomena in terms of NEWS coordinates, we discovered that solar flares tend to converge in the NE and SW quadrants of the solar disk, where they act as sources of sporadic storms. Meanwhile, coronal holes converge to solar longitudes of 0° and 180°, where they are sources of recurrent storms. Because of their concentration in the NE- and SW-quadrants, this correlation is referred to as the 'NEWS law'. The neutral line of the source surface shows a beautiful single wave in its declining phase, while it tends to show a double wave in the rising phase. Solar rotation numbers 2118 to 2119, where the neutral line exhibited two complicated asymmetric waves in both the N-S and S-W directions, were chosen for detailed analysis. Notwithstanding such an extremely complicated case, the NEWS law is satisfied when the double wave is separated into its two single-wave parts.

  6. The Equatorial Scintillations and Space Weather Effects on its Generation during Geomagnetic Storms

    Science.gov (United States)

    Biktash, Lilia

    Great diversity of the ionospheric phenomena leads to a variety of irregularity types with spatial size from many thousands of kilometers to few centimeters and lifetimes from days to fractions of second. Since the ionosphere strongly influences the propagation of radio waves, signal distortions caused by these irregularities affect short-wave transmissions on Earth, transiono-spheric satellite communications and navigation. In this work the solar wind and the equatorial ionosphere parameters, Kp, Dst, AU, AL indices characterized contribution of different mag-netospheric and ionospheric currents to the H-component of geomagnetic field are examined to test the space weather effect on the generation of ionospheric irregularities producing VLF scintillations. According to the results of the current statistical studies, one can predict scintil-lations from Aarons' criteria using the Dst index, which mainly depicts the magnetospheric ring current field. To amplify Aarons' criteria or to propose new criteria for predicting scintillation characteristics is the question. In the present phase of the experimental investigations of elec-tron density irregularities in the ionosphere new ways are opened up because observations in the interaction between the solar wind -magnetosphere -ionosphere during magnetic storms have progressed greatly. We have examined scintillation relation to magnetospheric and ionospheric currents and show that the factor, which presents during magnetic storms to fully inhibit scin-tillation, is the positive Bz-component of the IMF. During the positive Bz IMF F layer cannot raise altitude where scintillations are formed. The auroral indices and Kp do better for the prediction of the ionospheric scintillations at the equator. The interplanetary magnetic field data and models can be used to explain the relationship between the equatorial ionospheric parameters, h'F, foF2, and the equatorial geomagnetic variations with the polar ionosphere cur-rents and

  7. A Proton-Cyclotron Wave Storm Generated by Unstable Proton Distribution Functions in the Solar Wind

    Science.gov (United States)

    Wicks, R. T.; Alexander, R. L.; Stevens, M.; Wilson, L. B., III; Moya, P. S.; Vinas, A.; Jian, L. K.; Roberts, D. A.; O’Modhrain, S.; Gilbert, J. A.; hide

    2016-01-01

    We use audification of 0.092 seconds cadence magnetometer data from the Wind spacecraft to identify waves with amplitudes greater than 0.1 nanoteslas near the ion gyrofrequency (approximately 0.1 hertz) with duration longer than 1 hour during 2008. We present one of the most common types of event for a case study and find it to be a proton-cyclotron wave storm, coinciding with highly radial magnetic field and a suprathermal proton beam close in density to the core distribution itself. Using linear Vlasov analysis, we conclude that the long-duration, large-amplitude waves are generated by the instability of the proton distribution function. The origin of the beam is unknown, but the radial field period is found in the trailing edge of a fast solar wind stream and resembles other events thought to be caused by magnetic field footpoint motion or interchange reconnection between coronal holes and closed field lines in the corona.

  8. The Analysis of the Properties of Super Solar Proton Events and the Associated Phenomena

    Science.gov (United States)

    Cheng, L. B.; Le, G. M.; Lu, Y. P.; Chen, M. H.; Li, P.; Yin, Z. Q.

    2014-05-01

    The solar flare, the propagation speed of shock driven by coronal mass ejection (CME) from the sun to the Earth, the source longitudes and Carrington longitudes, and the geomagnetic storms associated with each super solar proton event with the peak flux equal to or exceeding 10000 pfu have been investigated. The analysis results show that the source longitudes of super solar proton events ranged from E30° to W75°. The Carrington longitudes of source regions of super solar proton events distributed in the two longitude bands, 130°˜220° and 260°˜320°, respectively. All super solar proton events were accompanied by major solar flares and fast CMEs. The averaged speeds of shocks propagated from the sun to the Earth were greater than 1200 km/s. Eight super solar proton events were followed by major geomagnetic storms (Dst≤-100 nT). One super solar proton event was followed by a geomagnetic storm with Dst=-96 nT.

  9. Solar-terrestrial disturbances of June-September 1982, 4

    International Nuclear Information System (INIS)

    Ohshio, Mitsuo; Koizumi, Tokuji; Hiidome, Shigeharu; Oda, Tadashi; Echizenya, Yoshimatsu; Kamishikiryo, Syogo; Maeno, Hideo

    1986-01-01

    As a distinctive feature of the ionosphere observed in 1982, it may be said that ionospheric disturbances caused by outstanding solar flares occurred frequently, and especially that the tendency was remarkable during the period from June to September 1982. First, the feature found was frequent sudden increases of f min (SIFs) caused by solar flares observed during the period from June 4 to July 19. Second, it contains ionospheric F region storms which occurred during the period from July 13 to 16, associated with a giant geomagnetic storm and during the periods from September 5 to 8 and from September 21 to 28, associated with usual geomagnetic storms. Ionospheric F region storms associated with these geomagnetic storms assumed various aspects due to the magnitude of geomagnetic storms, the local time of their occurrence, and their passage. Variations in these aspects were extensively investigated by utilizing data obtained not only at the five ionospheric sounding stations in Japan, but also in Eastern Asia, Europe, and so on. The four ionospheric F region storms investigated had individual characteristics due to the difference among local times of appearance in main phase of geomagnetic storms related to the ionospheric F region storms. The scale of the ionospheric F region storm associated with a giant geomagnetic storm on July 14, the decrease of which in horizontal component of geomagnetic field amounted to 630 nT at its maximum stage at Kakioka, was smaller than the scale of the ionospheric F region storm associated with a giant geomagnetic storm on August 4 ∼ 5, 1972 (359 nT there). (author)

  10. Ice Storms in a Changing Climate

    Science.gov (United States)

    2016-06-01

    CHANGING CLIMATE by Jennifer M. McNitt June 2016 Thesis Advisor: Wendell Nuss Co-Advisor: David W. Titley THIS PAGE INTENTIONALLY LEFT...SUBTITLE ICE STORMS IN A CHANGING CLIMATE 5. FUNDING NUMBERS 6. AUTHOR(S) Jennifer M. McNitt 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS...increase in global temperatures, due to climate change, could affect the frequency, intensity, and geographic location of ice storms. Three known ice

  11. Solar-terrestrial physics

    International Nuclear Information System (INIS)

    Patel, V.L.

    1977-01-01

    The Glossary is designed to be a technical dictionary that will provide solar workers of various specialties, students, other astronomers and theoreticians with concise information on the nature and the properties of phenomena of solar and solar-terrestrial physics. Each term, or group of related terms, is given a concise phenomenological and quantitative description, including the relationship to other phenomena and an interpretation in terms of physical processes. The references are intended to lead the non-specialist reader into the literature. This section deals with: geomagnetic field; coordinate systems; geomagnetic indices; Dst index; auroral electrojet index AE; daily, 27-day and semi-annual variations of geomagnetic field; micropulsation; geomagnetic storms; storm sudden commencement (SSC) or sudden commencement (SC); initial phase; ring current; sudden impulses; ionosphere; D region; polar cap absorption; sudden ionospheric disturbance; E region; sporadic E; equatorial electrojet; solar flare effect; F 1 and F 2 regions; spread F; travelling ionospheric disturbances; magnetosphere; magnetospheric coordinate systems; plasmasphere; magnetosheath; magnetospheric tail; substorm; radiation belts or Van Allen belts; whistlers; VLF emissions; aurora; auroral forms; auroral oval and auroral zones; auroral intensity; stable auroral red arcs; pulsing aurora; polar glow aurora; and airglow. (B.R.H.)

  12. Association of time of occurrence of electrical heart storms with environmental physical activity.

    Science.gov (United States)

    Stoupel, Eliiyahu; Kusniec, Jairo; Golovchiner, Gregory; Abramson, Evgeny; Kadmon, Udi; Strasberg, Boris

    2014-08-01

    Many publications in recent decades have reported a temporal link between medical events and environmental physical activity. The aim of this study was to analyze the time of occurrence of electrical heart storms against levels of cosmological parameters. The sample included 82 patients (71 male) with ischemic cardiomyopathy treated with an implantable cardioverter defibrillator at a tertiary medical center in 1999-2012 (5,114 days). The time of occurrence of all electrical heart storms, defined as three or more events of ventricular tachycardia or ventricular fibrillation daily, was recorded from the defibrillator devices. Findings were analyzed against data on solar, geomagnetic, and cosmic ray (neutron) activity for the same time period obtained from space institutions in the United States and Russia. Electrical storms occurred in all months of the year, with a slight decrease in July, August, and September. Most events took place on days with lower-than-average levels of solar and geomagnetic activity and higher-than-average levels of cosmic ray (neutron) activity. There was a significant difference in mean daily cosmic ray activity between the whole observation period and the days of electrical storm activity (P = 0.0001). These data extend earlier findings on the association of the timing of cardiac events and space weather parameters to the most dangerous form of cardiac arrhythmia-electric storms. Further studies are needed to delineate the pathogenetic mechanism underlying this association. ©2014 Wiley Periodicals, Inc.

  13. Correlations between Geomagnetic Disturbances and Field-Aligned Currents during the 22-29 July 2004 Storm Time Interval

    Science.gov (United States)

    Hood, R.; Woodroffe, J. R.; Morley, S.; Aruliah, A. L.

    2017-12-01

    Using the CHAMP fluxgate magnetometer to calculate field-aligned current (FAC) densities and magnetic latitudes, with SuperMAG ground magnetometers analogously providing ground geomagnetic disturbances (GMD) magnetic perturbations and latitudes, we probe FAC locations and strengths as predictors of GMD locations and strengths. We also study the relationships between solar wind drivers and global magnetospheric activity, and both FACs and GMDs using IMF Bz and the Sym-H index. We present an event study of the 22-29 July 2004 storm time interval, which had particularly large GMDs given its storm intensity. We find no correlation between FAC and GMD magnitudes, perhaps due to CHAMP orbit limitations or ground magnetometer coverage. There is, however, a correlation between IMF Bz and nightside GMD magnitudes, supportive of their generation via tail reconnection. IMF Bz is also correlated with dayside FAC and GMD magnetic latitudes, indicating solar wind as an initial driver. The ring current influence increases during the final storm, with improved correlations between the Sym-H index and both FAC magnetic latitudes and GMD magnitudes. Sym-H index correlations may only be valid for higher intensity storms; a statistical analysis of many storms is needed to verify this.

  14. Modeling the entry and trapping of solar energetic particles in the magnetosphere during the November 24-25, 2001 storm

    Science.gov (United States)

    Richard, R. L.; El-Alaoui, M.; Ashour-Abdalla, M.; Walker, R. J.

    2009-04-01

    We have modeled the entry of solar energetic particles (SEPs) into the magnetosphere during the November 24-25, 2001 magnetic storm and the trapping of particles in the inner magnetosphere. The study used the technique of following many test particles, protons with energies greater than about 100 keV, in the electric and magnetic fields from a global magnetohydrodynamic (MHD) simulation of the magnetosphere during this storm. SEP protons formed a quasi-trapped and trapped population near and within geosynchronous orbit. Preliminary data comparisons show that the simulation does a reasonably good job of predicting the differential flux measured by geosynchronous spacecraft. Particle trapping took place mainly as a result of particles becoming non-adiabatic and crossing onto closed field lines. Particle flux in the inner magnetosphere increased dramatically as an interplanetary shock impacted and compressed the magnetosphere near 0600 UT, but long term trapping (hours) did not become widespread until about an hour later, during a further compression of the magnetosphere. Trapped and quasi-trapped particles were lost during the simulation by motion through the magnetopause and by precipitation, primarily the former. This caused the particle population near and within geosynchronous orbit to gradually decrease later on during the latter part of the interval.

  15. Dynamic auroral storms on Saturn as observed by the Hubble Space Telescope.

    Science.gov (United States)

    Nichols, J D; Badman, S V; Baines, K H; Brown, R H; Bunce, E J; Clarke, J T; Cowley, S W H; Crary, F J; Dougherty, M K; Gérard, J-C; Grocott, A; Grodent, D; Kurth, W S; Melin, H; Mitchell, D G; Pryor, W R; Stallard, T S

    2014-05-28

    We present observations of significant dynamics within two UV auroral storms observed on Saturn using the Hubble Space Telescope in April/May 2013. Specifically, we discuss bursts of auroral emission observed at the poleward boundary of a solar wind-induced auroral storm, propagating at ∼330% rigid corotation from near ∼01 h LT toward ∼08 h LT. We suggest that these are indicative of ongoing, bursty reconnection of lobe flux in the magnetotail, providing strong evidence that Saturn's auroral storms are caused by large-scale flux closure. We also discuss the later evolution of a similar storm and show that the emission maps to the trailing region of an energetic neutral atom enhancement. We thus identify the auroral form with the upward field-aligned continuity currents flowing into the associated partial ring current.

  16. Solar-terrestrial disturbances of June-September 1982, 3

    International Nuclear Information System (INIS)

    Ogawa, Tadahiko

    1985-01-01

    Geomagnetic disturbances associated with the solar-terrestrial events during the period June-September 1982 are investigated using data of both solar phenomena and the satellite GMS-2 which measured solar protons and alpha particles at a geostationary orbit. It is pointed out (1) that the geomagnetic disturbances in June were weak in spite of successive, relatively large flares, (2) that the biggest geomagnetic storm during July 13-14 induced by the large flare (3B/X7.1) on July 12 is characterized by a geographically localized (around Japan), short-lived (1.5 hours) deep depression of geomagnetic H-component (ΔHsub(max) = -630 nT) appeared around local morning hours, (3) that two relatively big geomagnetic storms due to long-lasting, medium-scale flares occurred in September, and (4) that there existed storms caused not by flares but presumably by coronal hole and/or filament disappearance. According to the examination of world-wide magnetograms, it is tentatively suggested that the deep depression of H-component during the July 13-14 storm was caused by an abnormal expansion of the substorm-associated current system in the auroral zone to the Far East. All of the proton events due to the flares in the eastern solar hemisphere were of slow-onset type. Only one example of fast-onset type was obtained for the west limb flare on July 22. The present analyses are compared with the big solar-terrestrial events which happened in February 1958 and August 1972. (author)

  17. Long-term rise in geomagnetic activity - A close connection between quiet days and storms

    DEFF Research Database (Denmark)

    Vennerstrøm, Susanne

    2000-01-01

    Geomagnetic quiet days and magnetic storms are naturally believed to be due to very different solar wind conditions. In this study we however demonstrate that the long-term variation of geomagnetic quiet and disturbed days are surprisingly similar. By the use of daily averages of the geomagnetic.......7. The results indicate that the longterm,increase is due to an increase in the background solar wind parameters, rather than in the number of solar wind disturbances....

  18. Geomagnetic storms in the Antarctic F-region

    International Nuclear Information System (INIS)

    Wrenn, G.L.; Rodger, A.S.; Rishbeth, H.

    1987-01-01

    New analysis procedures are used to show that the main phase mid-latitude storm effects conform to consistent patterns in local time when suitable selection rules are applied, with averaging over several years. Changes in the maximum plasma frequency, foF2, with respect to estimated quiet-time values, are analysed in terms of asub(p)(t), a new geomagnetic index derived to take account of integrated disturbance. Reduction of foF2 is greatest during the early morning hours, in summer, at higher geomagnetic latitudes, near solar minimum and through the more active periods. The various dependencies are quantitatively determined for the first time by creating an average 'steady state' disturbance, rather than following specific storm events. This approach permits tests of competing theories using available modelling programs. (author)

  19. Observations and global numerical modelling of the St. Patrick's Day 2015 geomagnetic storm event

    Science.gov (United States)

    Foerster, M.; Prokhorov, B. E.; Doornbos, E.; Astafieva, E.; Zakharenkova, I.

    2017-12-01

    With a sudden storm commencement (SSC) at 04:45 UT on St. Patrick's day 2015 started the most severe geomagnetic storm in solar cycle 24. It appeared as a two-stage geomagnetic storm with a minimum SYM-H value of -233 nT. In the response to the storm commencement in the first activation, a short-term positive effect in the ionospheric vertical electron content (VTEC) occurred at low- and mid-latitudes on the dayside. The second phase commencing around 12:30 UT lasted longer and caused significant and complex storm-time changes around the globe with hemispherical different ionospheric storm reactions in different longitudinal ranges. Swarm-C observations of the neutral mass density variation along the orbital path as well as Langmuir probe plasma and magnetometer measurements of all three Swarm satellites and global TEC records are used for physical interpretations and modelling of the positive/negative storm scenario. These observations pose a challenge for the global numerical modelling of thermosphere-ionosphere storm processes as the storm, which occurred around spring equinox, obviously signify the existence of other impact factors than seasonal dependence for hemispheric asymmetries to occur. Numerical simulation trials using the Potsdam version of the Upper Atmosphere Model (UAM-P) are presented to explain these peculiar M-I-T storm processes.

  20. Relative outflow enhancements during major geomagnetic storms – Cluster observations

    Directory of Open Access Journals (Sweden)

    A. Schillings

    2017-12-01

    Full Text Available The rate of ion outflow from the polar ionosphere is known to vary by orders of magnitude, depending on the geomagnetic activity. However, the upper limit of the outflow rate during the largest geomagnetic storms is not well constrained due to poor spatial coverage during storm events. In this paper, we analyse six major geomagnetic storms between 2001 and 2004 using Cluster data. The six major storms fulfil the criteria of Dst  < −100 nT or Kp  > 7+. Since the shape of the magnetospheric regions (plasma mantle, lobe and inner magnetosphere are distorted during large magnetic storms, we use both plasma beta (β and ion characteristics to define a spatial box where the upward O+ flux scaled to an ionospheric reference altitude for the extreme event is observed. The relative enhancement of the scaled outflow in the spatial boxes as compared to the data from the full year when the storm occurred is estimated. Only O+ data were used because H+ may have a solar wind origin. The storm time data for most cases showed up as a clearly distinguishable separate peak in the distribution toward the largest fluxes observed. The relative enhancement in the outflow region during storm time is 1 to 2 orders of magnitude higher compared to less disturbed time. The largest relative scaled outflow enhancement is 83 (7 November 2004 and the highest scaled O+ outflow observed is 2  ×  1014 m−2 s−1 (29 October 2003.

  1. DISSOLUÇÃO DE FRONTEIRAS E A EXPERIÊNCIA TRANSICIONAL EM SOLAR STORMS, DE LINDA HOGAN

    Directory of Open Access Journals (Sweden)

    Caroline Garcia de Souza

    2014-12-01

    Full Text Available O presente trabalho analisa a experiência transicional no romance Solar Storms, publicado pela escritora nativo-americana Linda Hogan (Chickasaw em 1995. A obra narra a jornada de Angela, uma mestiça indígena órfã que retorna à terra de seus antepassados na tentativa de desvendar sua história e de religar os fragmentos de um passado parcialmente obscuro. Ao longo da narrativa, percebe-se um processo de gradual desconstrução de categorias – temporais, físicas, espaciais – e de superação das relações dicotômicas que opõem, por exemplo, indivíduo e comunidade, interioridade e exterioridade, o mundo humano e o não humano. Esse movimento se dá na direção de uma dissolução das falsas fronteiras e no sentido de uma integração total.

  2. Solar-Terrestrial Interactions

    National Research Council Canada - National Science Library

    Kahler, Stephen W

    2008-01-01

    ...) particle events, the solar wind, and geomagnetic storms. The investigators, working at Hanscom AFB, MA, have used many different kinds of space- and ground-based observations and have collaborated with workers at various institutions in this work...

  3. The driving mechanisms of particle precipitation during the moderate geomagnetic storm of 7 January 2005

    Directory of Open Access Journals (Sweden)

    N. Longden

    2007-10-01

    Full Text Available The arrival of an interplanetary coronal mass ejection (ICME triggered a sudden storm commencement (SSC at ~09:22 UT on the 7 January 2005. The ICME followed a quiet period in the solar wind and interplanetary magnetic field (IMF. We present global scale observations of energetic electron precipitation during the moderate geomagnetic storm driven by the ICME. Energetic electron precipitation is inferred from increases in cosmic noise absorption (CNA recorded by stations in the Global Riometer Array (GLORIA. No evidence of CNA was observed during the first four hours of passage of the ICME or following the sudden commencement (SC of the storm. This is consistent with the findings of Osepian and Kirkwood (2004 that SCs will only trigger precipitation during periods of geomagnetic activity or when the magnetic perturbation in the magnetosphere is substantial. CNA was only observed following enhanced coupling between the IMF and the magnetosphere, resulting from southward oriented IMF. Precipitation was observed due to substorm activity, as a result of the initial injection and particles drifting from the injection region. During the recovery phase of the storm, when substorm activity diminished, precipitation due to density driven increases in the solar wind dynamic pressure (Pdyn were identified. A number of increases in Pdyn were shown to drive sudden impulses (SIs in the geomagnetic field. While many of these SIs appear coincident with CNA, SIs without CNA were also observed. During this period, the threshold of geomagnetic activity required for SC driven precipitation was exceeded. This implies that solar wind density driven SIs occurring during storm recovery can drive a different response in particle precipitation to typical SCs.

  4. Ionospheric Response to the Magnetic Storm of 22 June 2015

    Science.gov (United States)

    Mansilla, Gustavo A.

    2018-03-01

    A global study is made of the response of the total electron content of the ionosphere (TEC) to the geomagnetic storm occurred on 22 June 2015 (one of the strongest geomagnetic storms of the current Solar Cycle 24). Using data from 44 sites, a hemispheric comparison is made by considering high latitudes (> 50°), middle latitudes (30°-50°) and low latitudes (30°N-30°S). The main features observed were: increases in TEC at high latitudes prior to the storm main phase, a considerable asymmetry of TEC response at middle and low latitudes of the Northern Hemisphere and the Southern Hemisphere and decreases at equatorial latitudes. The long duration enhancements in TEC were well correlated with increases in the O/N2 ratio but decreases in TEC had not associated decreases in the O/N2 ratio as occur with the decreases in the electron density. Besides, prompt penetration electric fields can play an important role in the equatorial and low-latitude ionosphere during main phase of the storm.

  5. Fundamental aspects affecting the return on investment from solar power plants

    International Nuclear Information System (INIS)

    Cintula, B.; Viglas, D.

    2012-01-01

    The article deals with fundamental parameters of solar cells-conversion efficiency of solar radiation into electricity and price of solar cells. These two aspects affect each other, so it is important to deal with both at once. In introduction are described the theoretical solutions about efficiency analysis. Furthermore the article is focused on a description of materials used in the photovoltaic cells. In addition, the article shows the price trend of photovoltaic cells for the last year. Finally, these two aspects are evaluated for return on investment in photovoltaic power plants. (Authors)

  6. Wind in the Solar System

    Science.gov (United States)

    McIntosh, Gordon

    2010-01-01

    As an astronomy instructor I am always looking for commonly experienced Earthly phenomena to help my students and me understand and appreciate similar occurrences elsewhere in the solar system. Recently I wrote short "TPT" articles on frost and precipitation. The present article is on winds in the solar system. A windy day or storm might…

  7. Observations of energetic helium ions in the Earth's radiation belts during a sequence of geomagnetic storms

    International Nuclear Information System (INIS)

    Spjeldvik, W.N.; Fritz, T.A.

    1981-01-01

    Every year a significant number of magnetic storms disturb the earth's magnetosphere and the trapped particle populations. In this paper, we present observations of energetic (MeV) helium ions made with Explorer 45 during a sequence of magnetic storms during June through December of 1972. The first of these storms started on June 17 and had a Dst index excursion to approx.190 gamma, and the MeV helium ions were perturbed primarily beyond 3 earth radii in the equatorial radiation belts with a typical flux increase of an order of magnitude at L = 4. The second storm period took place during August and was associated with very major solar flare activity. Although the Dst extremum was at best 35 gamma less than the June storm, this period can be characterized as irregular (or multi-storm) with strong compression of the magnetosphere and very large (order of magnitude) MeV helium ion flux enhancements down to Lapprox.2. Following this injection the trapped helium ion fluxes showed positive spectral slope with the peak beyond 3.15 MeV at L = 2.5; and at the lowest observable L shells (Lapprox.2--3) little flux decay (tau>100 days) was seen during the rest of the year. Any effects of two subsequent major magnetic storms in September and November were essentially undetectable in the prolonged after-effect of the August solar flare associated MeV helium ion injection. The helium ion radial profile of the phase space density showed a significant negative slope during this period, and we infer that radial diffusion constitutes a significant loss of helium ions on L shells above Lapprox. =4 during the aftermath of the August 1972 magnetic storm

  8. M-number dependence of rotation period of the solar magnetic field and its effect on coronal hole and solar flare

    International Nuclear Information System (INIS)

    Saito, Takao; Oki, Tosio

    1989-01-01

    The photospheric magnetic field is revealed to rotate with different solar rotation periods depending on its m-number, or its longitudinal range. The m-dependent rotation reveals the unexplained solar cycle variation of the 28-day period of the IMF 2-sector structure in inclining/minimum years and of the 27-day period in the declining/minimum years. The m-dependent rotation reveals also the unexplained 155-day periodicity in the occurrence of solar flare clusters, suggesting a motion of the sunspot field relative to the large-scale field. The IMF sector structure is closely related to recurrent geomagnetic storms, while the flare occurrence is related to sporadic SC storms. Hence, the m-dependent rotation is quite important in the study of the STE forecast. (author)

  9. Analysis of Total Electron Content and Electron Density Profile during Different Geomagnetic Storms

    Science.gov (United States)

    Chapagain, N. P.; Rana, B.; Adhikari, B.

    2017-12-01

    Total Electron content (TEC) and electron density are the key parameters in the mitigation of ionospheric effects on radio communication system. Detail study of the TEC and electron density variations has been carried out during geomagnetic storms, with longitude and latitude, for four different locations: (13˚N -17˚N, 88˚E -98˚E), (30˚N-50˚N, 120˚W -95˚W), (29˚S-26˚S, 167˚W-163˚W,) and (60˚S-45˚S, 120˚W-105˚W) using the Gravity Recovery and Climate Experiment (GRACE) satellite observations. In order to find the geomagnetic activity, the solar wind parameters such as north-south component of inter planetary magnetic field (Bz), plasma drift velocity (Vsw), flow pressure (nPa), AE, Dst and Kp indices were obtained from Operating Mission as Nodes on the Internet (OMNI) web system. The data for geomagnetic indices have been correlated with the TEC and electron density for four different events of geomagnetic storms on 6 April 2008, 27 March 2008, 4 September 2008, and 11 October 2008. The result illustrates that the observed TEC and electron density profile significantly vary with longitudes and latitudes. This study illustrates that the values of TEC and the vertical electron density profile are influenced by the solar wind parameters associated with solar activities. The peak values of electron density and TEC increase as the geomagnetic storms become stronger. Similarly, the electron density profile varies with altitudes, which peaks around the altitude range of about 250- 350 km, depending on the strength of geomagnetic storms. The results clearly show that the peak electron density shifted to higher altitude (from about 250 km to 350 km) as the geomagnetic disturbances becomes stronger.

  10. Statistical Properties of Geomagnetic Activity Indices and Solar Wind Parameters

    Directory of Open Access Journals (Sweden)

    Jung-Hee Kim

    2014-06-01

    Full Text Available As the prediction of geomagnetic storms is becoming an important and practical problem, conditions in the Earth’s magnetosphere have been studied rigorously in terms of those in the interplanetary space. Another approach to space weather forecast is to deal with it as a probabilistic geomagnetic storm forecasting problem. In this study, we carry out detailed statistical analysis of solar wind parameters and geomagnetic indices examining the dependence of the distribution on the solar cycle and annual variations. Our main findings are as follows: (1 The distribution of parameters obtained via the superimposed epoch method follows the Gaussian distribution. (2 When solar activity is at its maximum the mean value of the distribution is shifted to the direction indicating the intense environment. Furthermore, the width of the distribution becomes wider at its maximum than at its minimum so that more extreme case can be expected. (3 The distribution of some certain heliospheric parameters is less sensitive to the phase of the solar cycle and annual variations. (4 The distribution of the eastward component of the interplanetary electric field BV and the solar wind driving function BV2, however, appears to be all dependent on the solar maximum/minimum, the descending/ascending phases of the solar cycle and the equinoxes/solstices. (5 The distribution of the AE index and the Dst index shares statistical features closely with BV and BV2 compared with other heliospheric parameters. In this sense, BV and BV2 are more robust proxies of the geomagnetic storm. We conclude by pointing out that our results allow us to step forward in providing the occurrence probability of geomagnetic storms for space weather and physical modeling.

  11. Solar wind parameters responsible for the plasma injection into the magnetospheric ring current region

    International Nuclear Information System (INIS)

    Bobrov, M.S.

    1977-01-01

    Solar wind effect on the magnetospheric ring-current region has been considered. The correlations with solar wind parameters of the magnitude qsub(o) proportional to the total energy of particles being injected into the magnetospheric ring-current region per one hour are studied statistically and by comparison of time variations. The data on 8 sporadic geomagnetic storms of various intensity, from moderate to very severe one, are used. It is found that qsub(o) correlates not only with the magnitude and the direction of the solar-wind magnetic field component normal to the ecliptic plane, Bsub(z), but also with the variability, sigmasub(B), of the total magnetic-field strength vector. The solar-wind flux velocity ν influences the average storm intensity but the time variations of ν during any individual storm do not correlate with those of qsub(o)

  12. Origin-Dependent Variations in the Atmospheric Microbiome in Eastern Mediterranean Dust Storms

    Science.gov (United States)

    Rudich, Y.; Gat, D.

    2017-12-01

    Microorganisms carried by dust storms are transported through the atmosphere and may affect human health and the functionality of microbial communities in various environments. Characterizing the dust-borne microbiome in dust storms of different origins, or that followed different trajectories, provides valuable data to improve our understanding of global health and environmental impacts. We present a comparative study on the diversity of dust- borne bacterial communities in dust storms from three distinct origins—North Africa, Syria and Saudi Arabia—and compare them with local bacterial communities sampled on clear days, all collected at a single location, in Israel. Storms from different dust origins exhibited distinct bacterial communities, with signature bacterial taxa for each source. Dust storms were characterized by a lower abundance of selected antibiotic resistance genes (ARGs) compared with ambient dust, asserting that the origin of these genes is local, possibly anthropogenic. With the progression of the storm, the storm-borne bacterial community showed increasing resemblance to ambient dust, suggesting mixing with local dust. We will also discuss how exposure to dust containing biological components affect lung epithelial cells. These results show, for the first time, that dust storms from different sources display distinct bacterial communities, suggesting possible distinct effects on the environment and public health.

  13. Solar storm effects during Saint Patrick's Days in 2013 and 2015 on the Schumann resonances measured by the ELF station at Sierra Nevada (Spain)

    Science.gov (United States)

    Salinas, A.; Toledo-Redondo, S.; Navarro, E. A.; Fornieles-Callejón, J.; Portí, J. A.

    2016-12-01

    The effects of solar storms occurring during the days 17 to 19 March 2013 and 2015, St. Patrick's Day intervals, on Schumann resonances (SRs) have been studied. To do this, the experimental data recorded by the Juan Antonio Morente extremely low frequency station located at Sierra Nevada, Spain, have been processed in order to obtain hourly averaged information on the first three resonance modes. Results are compared with monthly averages of the SR data for each hour to detect deviations from the regular behavior. Evidence of significant changes in the peak amplitudes and frequencies of the SRs have been identified in the station's measurements and related to the coronal mass ejection impact in the magnetosphere, detected by in situ plasma measurements onboard spacecraft in the solar wind. However, the complicated nature of the Schumann resonances, dependent on multiple variables and subject to multiple unavoidable interferences (e.g., lightning or human radio sources), in conjunction with the complex magnetosphere-ionosphere-atmosphere coupling processes, makes it difficult to conclude that the observed deviations are exclusively due to the solar events mentioned. Results extracted from only two solar events cannot be considered as conclusive, and therefore, independent comparison with results reported by other research would seem advisable in future works on this subject.

  14. Mathematical models of some geomagnetic storms with SC

    International Nuclear Information System (INIS)

    Ivanova, P.K.

    1990-01-01

    Regressive equations for H horizontal component of three geomagnetic storms with Sc:0.1.03.82, 24.01.74 and 23.03.69 -are calculated using step-by-step regression analysis. These equations relate H with parameters of solar wind and interplanetary magnetic field. Nonlinear, square, logarithmic and trigonometric dependences are considered, as well. Most essential parameters, which contribute mostly into Sc, are determined from multiplicity (46 factors) of independent parameters

  15. VLF Wave Properties During Geomagnetic Storms

    Science.gov (United States)

    Blancarte, J.; Artemyev, A.; Mozer, F.; Agapitov, O. V.

    2017-12-01

    Whistler-mode chorus is important for the global dynamics of the inner magnetosphere electron population due to its ability to scatter and accelerate electrons of a wide energy range in the outer radiation belt. The parameters of these VLF emissions change dynamically during geomagnetic storms. Presented is an analysis of four years of Van Allen probe data, utilizing electric and magnetic field in the VLF range focused on the dynamics of chorus wave properties during the enhancement of geomagnetic activity. It is found that VLF emissions respond to geomagnetic storms in more complicated ways than just by affecting the waves' amplitude growth or depletion. Oblique wave amplitudes grow together with parallel waves during periods of intermediate geomagnetic activity, while the occurrence rate of oblique waves decreases during larger geomagnetic storms.

  16. The storm-time ring current: a statistical analysis at two widely separated low-latitude stations

    Directory of Open Access Journals (Sweden)

    P. Francia

    2004-11-01

    Full Text Available We conducted a statistical analysis of the geomagnetic field variations during the storm main phase at two low-latitude stations, separated by several hours in magnetic local time, in order to investigate the asymmetry and longitudinal extent of the storm-time ring current. The results show evidence for an asymmetric current which typically extends from evening to noon and, during moderate solar wind electric field conditions, up to the early morning, confirming the important role of the magnetospheric convection in the ring current energization. We also analyzed a possible relationship between the local current intensity during the storm main phase and the substorm activity observed at different time delays τ with respect to the storm onset. The results show a significant anticorrelation for τ =-1h, indicating that if the substorm activity is high just before the storm, a weaker ring current develops.

  17. Solar-terrestrial disturbances of June-September 1982, 3

    International Nuclear Information System (INIS)

    Ogawa, Tadahiko

    1986-01-01

    Geomagnetic disturbances associated with the solar-terrestrial events during the period June-September 1982 are investigated using data of both solar phenomena and the satellite GMS-2 which measured solar protons and alpha particles at a geostationary orbit. It is pointed out (1) that the geomagnetic disturbances in June were weak in spite of relatively large, successive flares, (2) that the biggest geomagnetic storm during July 13 - 14 induced by the large flare (3B/X7.1) on July 12 is characterized by a geographically localized (around Japan), short-lived (1.5 hours) deep depression of geomagnetic H-component (ΔH max = -630 nT) which appeared around local morning hours, (3) that two relatively big geomagnetic storms due to long-lasting, medium-scale flares occurred in September, and (4) that there existed storms caused not by flares but presumably by coronal hole and/or filament disappearance. According to the examination of world-wide magnetograms, it is tentatively suggested that the deep depression of H-component during the July 13 - 14 storm was caused by an abnormal expansion of the substorm-associated current system in the auroral zone toward the Far East. All of the proton events due to the flares in the eastern solar hemisphere were of slow-onset type. Only one example of fast-onset type was obtained for the west limb flare on July 22. The present analyses are compared with the big solarterrestrial events which happened in February 1958 and August 1972. (author)

  18. AMPTE/CCE observations of the plasma composition below 17 keV during the September 4, 1984 magnetic storm

    International Nuclear Information System (INIS)

    Shelley, E.G.; Klumpar, D.M.; Peterson, W.K.; Ghielmetti, A.; Balsiger, H.; Geiss, J.; Rosenbauer, H.; Bern Universitaet, Switzerland; Max-Planck-Institut fuer Aeronomie, Katlenburg, West Germany)

    1985-01-01

    Observations from the Hot Plasma Composition Experiment on the AMPTE/CCE spacecraft during the magnetic storm of 4-5 September 1984 reveal that significant injection of ions of terrestrial origin accompanied the storm development. The compression of the magnetosphere at storm sudden commencement carried the magnetopause inside the CCE orbit clearly revealing the shocked solar wind plasma. A build up of suprathermal ions is observed near the plasmapause during the storm main phase and recovery phase. Pitch angle distributions in the ring current during the main phase show differences between H(+) and O(+) that suggest mass dependent injection, transport and/or loss processes. 9 references

  19. A new ionospheric storm scale based on TEC and foF2 statistics

    Science.gov (United States)

    Nishioka, Michi; Tsugawa, Takuya; Jin, Hidekatsu; Ishii, Mamoru

    2017-01-01

    In this paper, we propose the I-scale, a new ionospheric storm scale for general users in various regions in the world. With the I-scale, ionospheric storms can be classified at any season, local time, and location. Since the ionospheric condition largely depends on many factors such as solar irradiance, energy input from the magnetosphere, and lower atmospheric activity, it had been difficult to scale ionospheric storms, which are mainly caused by solar and geomagnetic activities. In this study, statistical analysis was carried out for total electron content (TEC) and F2 layer critical frequency (foF2) in Japan for 18 years from 1997 to 2014. Seasonal, local time, and latitudinal dependences of TEC and foF2 variabilities are excluded by normalizing each percentage variation using their statistical standard deviations. The I-scale is defined by setting thresholds to the normalized numbers to seven categories: I0, IP1, IP2, IP3, IN1, IN2, and IN3. I0 represents a quiet state, and IP1 (IN1), IP2 (IN2), and IP3 (IN3) represent moderate, strong, and severe positive (negative) storms, respectively. The proposed I-scale can be used for other locations, such as polar and equatorial regions. It is considered that the proposed I-scale can be a standardized scale to help the users to assess the impact of space weather on their systems.

  20. The ion population of the magnetotail during the 17 April 2002 magnetic storm: Large-scale kinetic simulations and IMAGE/HENA observations

    Science.gov (United States)

    Peroomian, Vahé; El-Alaoui, Mostafa; Brandt, Pontus C.:son

    2011-05-01

    The contribution of solar wind and ionospheric ions to the ion population of the magnetotail during the 17 April 2002 geomagnetic storm was investigated by using large-scale kinetic (LSK) particle tracing calculations. We began our investigation by carrying out a global magnetohydrodynamic simulation of the storm event by using upstream solar wind and interplanetary magnetic field data from the ACE spacecraft. We launched solar wind H+ ions and ionospheric O+ ions beginning at 0900 UT, ˜2 h prior to the sudden storm commencement (SSC), until 2000 UT. We found that during this Dst ˜ -98 nT storm, solar wind ions carried the bulk of the density and energy density in the nightside ring current and plasma sheet, with the notable exception of the 90 min immediately after the SSC when O+ densities in the ring current exceeded those of H+ ions. The LSK simulation did a very good job of reproducing ion densities observed by the Los Alamos National Laboratory spacecraft at geosynchronous orbit and reproduced the changes in the inner magnetosphere and the injection of ions observed by the IMAGE spacecraft during a substorm that occurred at 1900 UT. These comparisons with observations serve to validate our results throughout the magnetotail and allow us to obtain time-dependent maps of H+ and O+ density and energy density where IMAGE cannot make measurements. In essence, this work extends the viewing window of the IMAGE spacecraft far downtail.

  1. Acute and emergency care for thyrotoxicosis and thyroid storm

    Science.gov (United States)

    2015-01-01

    Thyroid hormones affect all organ systems and, in excess, can cause increased metabolic rate, heart rate, ventricle contractility, and gastrointestinal motility as well as muscle and central nervous system excitability. Thyroid storm is the extreme manifestation of thyrotoxicosis with an estimated incidence of 0.20 per 100,000 per year among hospitalized patients in Japan. The mortality of thyroid storm without treatment ranges from 80% to 100%; but with treatment, the mortality rate is between 10% and 50%. The diagnostic strategy for thyroid storm may take into consideration Burch–Wartofsky scoring or Akamizu's diagnostic criteria. Multiple treatment aims need to be addressed in managing thyroid storm effectively. This paper puts together all aspects to be considered for the management of hyperthyroidism and thyroid storm during the acute and emergency phase as well as consideration of special populations. PMID:29123713

  2. Acute and emergency care for thyrotoxicosis and thyroid storm.

    Science.gov (United States)

    Idrose, Alzamani Mohammad

    2015-07-01

    Thyroid hormones affect all organ systems and, in excess, can cause increased metabolic rate, heart rate, ventricle contractility, and gastrointestinal motility as well as muscle and central nervous system excitability. Thyroid storm is the extreme manifestation of thyrotoxicosis with an estimated incidence of 0.20 per 100,000 per year among hospitalized patients in Japan. The mortality of thyroid storm without treatment ranges from 80% to 100%; but with treatment, the mortality rate is between 10% and 50%. The diagnostic strategy for thyroid storm may take into consideration Burch-Wartofsky scoring or Akamizu's diagnostic criteria. Multiple treatment aims need to be addressed in managing thyroid storm effectively. This paper puts together all aspects to be considered for the management of hyperthyroidism and thyroid storm during the acute and emergency phase as well as consideration of special populations.

  3. Space Weather Monitoring for ISS Geomagnetic Storm Studies

    Science.gov (United States)

    Minow, Joseph I.; Parker, Linda Neergaard

    2013-01-01

    The International Space Station (ISS) space environments community utilizes near real time space weather data to support a variety of ISS engineering and science activities. The team has operated the Floating Potential Measurement Unit (FPMU) suite of plasma instruments (two Langmuir probes, a floating potential probe, and a plasma impedance probe) on ISS since 2006 to obtain in-situ measurements of plasma density and temperature along the ISS orbit and variations in ISS frame potential due to electrostatic current collection from the plasma environment (spacecraft charging) and inductive (vxB) effects from the vehicle motion across the Earth s magnetic field. An ongoing effort is to use FPMU for measuring the ionospheric response to geomagnetic storms at ISS altitudes and investigate auroral charging of the vehicle as it passes through regions of precipitating auroral electrons. This work is challenged by restrictions on FPMU operations that limit observation time to less than about a third of a year. As a result, FPMU campaigns ranging in length from a few days to a few weeks are typically scheduled weeks in advance for ISS engineering and payload science activities. In order to capture geomagnetic storm data under these terms, we monitor near real time space weather data from NASA, NOAA, and ESA sources to determine solar wind disturbance arrival times at Earth likely to be geoeffective (including coronal mass ejections and high speed streams associated with coronal holes) and activate the FPMU ahead of the storm onset. Using this technique we have successfully captured FPMU data during a number of geomagnetic storm periods including periods with ISS auroral charging. This presentation will describe the strategies and challenges in capturing FPMU data during geomagnetic storms, the near real time space weather resources utilized for monitoring the space weather environment, and provide examples of auroral charging data obtained during storm operations.

  4. Geomagnetic storms and electric fields in the equatorial ionosphere

    International Nuclear Information System (INIS)

    Rastogi, R.G.

    1977-01-01

    Using direct measurements of equatorial electric field during a geomagnetic storm it is shown that the large decrease in the field observed near the dip equator is due to the reversal of the equatorial electrojet current. This is caused by the imposition of an additional westward electric field on the equatorial ionosphere which was originated by the interaction of solar wind with the interplanetary magnetic field. (author)

  5. Prediction of geomagnetic storms from solar wind data with the use of a neural network

    Directory of Open Access Journals (Sweden)

    H. Lundstedt

    Full Text Available An artificial feed-forward neural network with one hidden layer and error back-propagation learning is used to predict the geomagnetic activity index (Dst one hour in advance. The Bz-component and ΣBz, the density, and the velocity of the solar wind are used as input to the network. The network is trained on data covering a total of 8700 h, extracted from the 25-year period from 1963 to 1987, taken from the NSSDC data base. The performance of the network is examined with test data, not included in the training set, which covers 386 h and includes four different storms. Whilst the network predicts the initial and main phase well, the recovery phase is not modelled correctly, implying that a single hidden layer error back-propagation network is not enough, if the measured Dst is not available instantaneously. The performance of the network is independent of whether the raw parameters are used, or the electric field and square root of the dynamical pressure.

  6. Sensitivity study of surface wind flow of a limited area model simulating the extratropical storm Delta affecting the Canary Islands

    OpenAIRE

    Marrero, C.; Jorba, O.; Cuevas, E.; Baldasano, J. M.

    2009-01-01

    In November 2005 an extratropical storm named Delta affected the Canary Islands (Spain). The high sustained wind and intense gusts experienced caused significant damage. A numerical sensitivity study of Delta was conducted using the Weather Research & Forecasting Model (WRF-ARW). A total of 27 simulations were performed. Non-hydrostatic and hydrostatic experiments were designed taking into account physical parameterizations and geometrical factors (size and position of the outer domain, d...

  7. Future changes in extratropical storm tracks and baroclinicity under climate change

    NARCIS (Netherlands)

    Lehmann, Jascha; Coumou, Dim; Frieler, Katja; Eliseev, Alexey V.; Levermann, Anders

    2014-01-01

    The weather in Eurasia, Australia, and North and South America is largely controlled by the strength and position of extratropical storm tracks. Future climate change will likely affect these storm tracks and the associated transport of energy, momentum, and water vapour. Many recent studies have

  8. Statistical study of interplanetary condition effect on geomagnetic storms: 2. Variations of parameters

    Science.gov (United States)

    Yermolaev, Yu. I.; Lodkina, I. G.; Nikolaeva, N. S.; Yermolaev, M. Yu.

    2011-02-01

    We investigate the behavior of mean values of the solar wind’s and interplanetary magnetic field’s (IMF) parameters and their absolute and relative variations during the magnetic storms generated by various types of the solar wind. In this paper, which is a continuation of paper [1], we, on the basis of the OMNI data archive for the period of 1976-2000, have analyzed 798 geomagnetic storms with D st ≤ -50 nT and their interplanetary sources: corotating interaction regions CIR, compression regions Sheath before the interplanetary CMEs; magnetic clouds MC; “Pistons” Ejecta, and an uncertain type of a source. For the analysis the double superposed epoch analysis method was used, in which the instants of the magnetic storm onset and the minimum of the D st index were taken as reference times. It is shown that the set of interplanetary sources of magnetic storms can be sub-divided into two basic groups according to their slowly and fast varying characteristics: (1) ICME (MC and Ejecta) and (2) CIR and Sheath. The mean values, the absolute and relative variations in MC and Ejecta for all parameters appeared to be either mean or lower than the mean value (the mean values of the electric field E y and of the B z component of IMF are higher in absolute value), while in CIR and Sheath they are higher than the mean value. High values of the relative density variation sN/ are observed in MC. At the same time, the high values for relative variations of the velocity, B z component, and IMF magnitude are observed in Sheath and CIR. No noticeable distinctions in the relationships between considered parameters for moderate and strong magnetic storms were observed.

  9. Ionospheric Response to St. Patrick's Day Storm of 2015 Over Indian Region: Ionosonde and All-Sky Imager Observations

    Science.gov (United States)

    Gupta, S.; Upadhayaya, A. K.; Taori, A. K.; Kotnala, R. K.

    2017-12-01

    The St. Patrick's Day Storm of 2015 was the first superstorm of 24th solar cycle, with Dst dipping down to -223 nT. The response of this severe (G4) storm is studied using ionosonde data at low-mid latitude Indian station, Delhi (28.6°N, 77.2°E), along with 630.0 nm night airglow observations from low latitude Indian station, Gadanki (13.5°N, 79.2°E). A peculiar occurrence of additional stratification, not observed before at this latitude, is found to be present between F1 and F2 layers before the SSC of the storm. This observed extra stratification in F layer (F1.5) is attributed to TIDs during vertically uplifted F region. Apart from this, additional stratification above F2 layer, lasting for about half an hour, was seen during this storm. A large variation in F2 layer critical parameters, showing both positive and negative phases, with electron density enhancement of 264% and depression of 65%, is observed during this storm. Contrary to the previous reports, Spread-F occurrence at Delhi do not follow anticorrelation with solar activity. The night airglow observations of 630.0 nm from Gadanki indicates towards the presence of external forcing which results in drifting of plasma in the opposite direction (westward) to that of normally seen, during this St. Patrick's Day storm of 2015. The variation in neutral composition (O/N2 taken from GUVI) is found during this storm. This result suggests O/N2 ratio to be a vital contributor, apart from the electric field and neutral wind, in determining the ionospheric response to such transient events.

  10. Energy Savings of Low-E Storm Windows and Panels across US Climate Zones

    Energy Technology Data Exchange (ETDEWEB)

    Culp, Thomas D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cort, Katherine A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-10-01

    This report builds off of previous modeling work related to low-e storm windows used to create a "Database of U.S. Climate-Based Analysis for Low-E Storm Windows." This work updates similar studies using new fuel costs and examining the separate contributions of reduced air leakage and reduced coefficients of overall heat transfer and solar heat gain. In this report we examine the energy savings and cost effectiveness of low-E storm windows in residential homes across a broad range of U.S. climates, excluding the impact from infiltration reductions, which tend to vary using the National Energy Audit Tool (NEAT) and RESFEN model calculations. This report includes a summary of the results, NEAT and RESFEN background, methodology, and input assumptions, and an appendix with detailed results and assumptions by climate zone.

  11. Helio-Geomagnetic Activity and the Time Distribution of Myocardial Infractions during the Solar Cycle 23 (1997-2007). A Preliminary Study based on a Greek Hospital Data

    Science.gov (United States)

    Moussas, X.; Preka-Papadema, P.; Apostolou, Th.; Katsavrias, Ch.; Theodoropoulou, A.; Papadima, Th.

    2010-01-01

    We present the time distribution of a large number (7798) of Myocardial Infractions (MI) recorded at the General Hospital `St. Panteleimon' of the city of Nikea (in Piraeus, Greece), during time interval 1997-2007. This data set consisted of 5160 NON-STEACS (non-ST) and 2638 STEACS (ST) infractions are examined along with the monthly numbers of solar flares and Coronal Mass Ejections (CMEs), solar wind parameters and the geomagnetic activity (Dst geomagnetic index and other). The mean monthly value of ST and non-ST events is 20 and 40 respectively. The maximum monthly value of non-ST events (72 and 73) are recorded in October 2002 and January 2003, as well as the one of ST events (32), while solar maximum, recorded in November 2002. This time interval is characterized by magnetic storms from August 2002 peaked in October 2002 and ended in February 2003. It is noticeable that August 2002 corresponds to the solar maximum of CMEs and strong solar flares monthly values. The maximum monthly value of ST events (40) is recorded in November 2005 almost simultaneously with a sudden absence of solar flares (October 2005). Increased values have been recorded during a period of extreme solar events of October-November 2003 and January-March 2005. It seems from this extensive statistical study that there is an association between the monthly values of MI and of CMEs; the non-ST MI shows a better association with CMEs. Moreover, the MI yearly distribution is in accordance with the time distribution of magnetic storms (number and duration). The non-ST distribution is also affected by intense magnetic storms.

  12. Data-based Modeling of the Dynamical Inner Magnetosphere During Strong Geomagnetic Storms

    Science.gov (United States)

    Tsyganenko, N.; Sitnov, M.

    2004-12-01

    This work builds on and extends our previous effort [Tsyganenko et al., 2003] to develop a dynamical model of the storm-time geomagnetic field in the inner magnetosphere, using space magnetometer data taken during 37 major events in 1996--2000 and concurrent observations of the solar wind and IMF. The essence of the approach is to derive from the data the temporal variation of all major current systems contributing to the geomagnetic field during the entire storm cycle, using a simple model of their growth and decay. Each principal source of the external magnetic field (magnetopause, cross-tail current sheet, axisymmetric and partial ring currents, Birkeland currents) is controlled by a separate driving variable that includes a combination of geoeffective parameters in the form Nλ Vβ Bsγ , where N, V, and Bs are the solar wind density, speed, and the magnitude of the southward component of the IMF, respectively. Each source was also assumed to have an individual relaxation timescale and residual quiet-time strength, so that its partial contribution to the total field was calculated for any moment as a time integral, taking into account the entire history of the external driving of the magnetosphere during each storm. In addition, the magnitudes of the principal field sources were assumed to saturate during extremely large storms with abnormally strong external driving. All the parameters of the model field sources, including their magnitudes, geometrical characteristics, solar wind/IMF driving functions, decay timescales, and saturation thresholds were treated as free variables, to be derived from the data by the least squares. The relaxation timescales of the individual magnetospheric field sources were found to largely differ between each other, from as large as ˜30 hours for the symmetrical ring current to only ˜50 min for the region~1 Birkeland current. The total magnitudes of the currents were also found to dramatically vary in the course of major storms

  13. Formation of a strong southward IMF near the solar maximum of cycle 23

    Directory of Open Access Journals (Sweden)

    S. Watari

    2004-01-01

    Full Text Available We analyzed observations of the solar activities and the solar wind parameters associated with large geomagnetic storms near the maximum of solar cycle 23. This analysis showed that strong southward interplanetary magnetic fields (IMFs, formed through interaction between an interplanetary disturbance, and background solar wind or between interplanetary disturbances are an important factor in the occurrence of intense geomagnetic storms. Based on our analysis, we seek to improve our understanding of the physical processes in which large negative Bz's are created which will lead to improving predictions of space weather.

    Key words. Interplanetary physics (Flare and stream dynamics; Interplanetary magnetic fields; Interplanetary shocks

  14. Role of solar influences on geomagnetosphere and upper atmosphere

    Science.gov (United States)

    Kumar Tripathi, Arvind

    The Earth's magnetosphere and upper atmosphere can be greatly perturbed by variations in the solar luminosity caused by disturbances on the solar surface. The state of near-Earth space environment is governed by the Sun and is very dynamic on all spatial and temporal scale. The geomagnetic field which protects the Earth from solar wind and cosmic rays is also essential to the evolution of life; its variations can have either direct or indirect effect on human physiology and health state even if the magnitude of the disturbance is small. Geomagnetic disturbances are seen at the surface of the Earth as perturbations in the components of the geomagnetic field, caused by electric currents flowing in the magnetosphere and upper atmosphere. Ionospheric and thermospheric storms also result from the redistribution of particles and fields. Global thermospheric storm winds and composition changes are driven by energy injection at high latitudes. These storm effects may penetrate downwards to the lower thermosphere and may even perturb the mesosphere. Many of the ionospheric changes at mid-latitude can be understood as a response to thermospheric perturbations. The transient bursts of solar energetic particles, often associated with large solar transients, have been observed to have effects on the Earth's middle and lower atmosphere, including the large-scale destruction of polar stratospheric and tropospheric ozone. In the present, we have discussed effect of solar influences on earth's magnetosphere and upper atmosphere that are useful to space weather and global warming, on the basis of various latest studies.

  15. Analysis of Storm Surge in Hong Kong

    Science.gov (United States)

    Kao, W. H.

    2017-12-01

    A storm surge is a type of coastal flood that is caused by low-pressure systems such as tropical cyclones. Storm surges caused by tropical cyclones can be very powerful and damaging, as they can flood coastal areas, and even destroy infrastructure in serious cases. Some serious cases of storm surges leading to more than thousands of deaths include Hurricane Katrina (2005) in New Orleans and Typhoon Haiyan (2013) in Philippines. Hong Kong is a coastal city that is prone to tropical cyclones, having an average of 5-6 tropical cyclones entering 500km range of Hong Kong per year. Storm surges have seriously damaged Hong Kong in the past, causing more than 100 deaths by Typhoon Wanda (1962), and leading to serious damage to Tai O and Cheung Chau by Typhoon Hagupit (2008). To prevent economic damage and casualties from storm surges, accurately predicting the height of storm surges and giving timely warnings to citizens is very important. In this project, I will be analyzing how different factors affect the height of storm surge, mainly using data from Hong Kong. These factors include the windspeed in Hong Kong, the atmospheric pressure in Hong Kong, the moon phase, the wind direction, the intensity of the tropical cyclone, distance between the tropical cyclone and Hong Kong, the direction of the tropical cyclone relative to Hong Kong, the speed of movement of the tropical cyclone and more. My findings will also be compared with cases from other places, to see if my findings also apply for other places.

  16. Particle precipitation influence in the conductivity of the auroral ionosphere during magnetic storms

    International Nuclear Information System (INIS)

    Monreal M, R.; Llop, C.

    2002-01-01

    The study of the energy transfer between the different regions of the solar wind - magnetosphere - ionosphere system is probably the main goal in Solar-Terrestrial Physics. In the magnetosphere - ionosphere coupling, the ionosphere power dissipation is highly sensitive to the conductivity in such a way that a detailed knowledge of this property in the auroral and polar ionosphere is of great interest because it is important not only to determine Joule heat, but also for electric fields and currents models including the field aligned currents coupling the magnetosphere and ionosphere. The main sources of ionization and subsequent conductivity in the ionosphere are due to the emission of electromagnetic radiation and charged energetic particles from the sun. In this work it is analysed the influence of the precipitating electrons on the auroral ionosphere conductivity during magnetic storms. It is shown that the conductance values appear sub estimated for high levels of activity due to the saturation produced during very intense magnetic storms. (Author)

  17. Two-dimensional numerical modeling of the cosmic ray storm

    International Nuclear Information System (INIS)

    Kadokura, A.; Nishida, A.

    1986-01-01

    A numerical model of the cosmic ray storm in the two-dimensional heliosphere is constructed incorporating the drift effect. We estimate the effect of a flare-associated interplanetary shock and the disturbed region behind it (characterized by enhancement in velocity and magnetic field, and decrease in mean free path) on the density and anisotropy of cosmic rays in the heliosphere. As the disturbance propagates outward, a density enhancement appears on the front side, and a density depression region is produced on the rear side. The effect of drift on the cosmic ray storm appears most clearly in the higher-latitude region. For the parallel (antiparallel) state of the solar magnetic field which corresponds to the pre(post-) 1980 period, the density in the higher-latitude region decreases (increases) before the shock arrival. The maximum density depression near the earth for the parallel state is greater than for the antiparallel state, and the energy spectrum of the density depression in percentage is softer for the parallel state than for the antiparallel state. Prior to the arrival of the shock, the phase of solar diurnal anisotropy begins to shift to the earlier hours, and its amplitude becomes greater for both polarity states. North-south anisotropy also becomes greater because of the enhanced drift for both polarity states

  18. Behaviour of the interplanetary and magnetospheric electric fields during very intense storms

    International Nuclear Information System (INIS)

    Wu, Lei; Gendrin, R.; Higel, B.

    1982-01-01

    A study is made of the role which a positive (northward) component of the interplanetary magnetic field (IMF) Bsub(z) may play in triggering large magnetic storms. The study is made over a 15 year period (1964-1978) by selecting storms with Ksub(p) >= 7 0 and which are preceded by a Sudden Commencement (Ssc). The correlation between the geomagnetic index Ksub(m) and the three-hourly averaged Bsub(z) is established both on a statistical basis and on a case-by-case study. Storms associated with Bsub(z) > 0 are found to be less intense than those associated with Bsub(z) < 0, but major storms can be also triggered by solar wind events associated with a northward IMF. The relation-ship between interplanetary electric field Esub(γ) and Ksub(m) is also given. By using this relation together with the one between Esub(M) and Ksub(m) which has been established in previous studies (where Esub(M) is the magnetospheric convection electric field), it is possible to study the transfer efficiency of the magnetosphere. It is found that the transfer coefficient ΔEsub(M)/ΔEsub(γ) is much smaller for intense storms than for moderate ones, the latter having been studied in a previous paper (Wu Lei et al., 1981)

  19. Learning Storm

    CERN Document Server

    Jain, Ankit

    2014-01-01

    If you are a Java developer who wants to enter into the world of real-time stream processing applications using Apache Storm, then this book is for you. No previous experience in Storm is required as this book starts from the basics. After finishing this book, you will be able to develop not-so-complex Storm applications.

  20. Deep Space Storm Shelter Simulation Study

    Science.gov (United States)

    Dugan, Kathryn; Phojanamongkolkij, Nipa; Cerro, Jeffrey; Simon, Matthew

    2015-01-01

    Missions outside of Earth's magnetic field are impeded by the presence of radiation from galactic cosmic rays and solar particle events. To overcome this issue, NASA's Advanced Exploration Systems Radiation Works Storm Shelter (RadWorks) has been studying different radiation protective habitats to shield against the onset of solar particle event radiation. These habitats have the capability of protecting occupants by utilizing available materials such as food, water, brine, human waste, trash, and non-consumables to build short-term shelters. Protection comes from building a barrier with the materials that dampens the impact of the radiation on astronauts. The goal of this study is to develop a discrete event simulation, modeling a solar particle event and the building of a protective shelter. The main hallway location within a larger habitat similar to the International Space Station (ISS) is analyzed. The outputs from this model are: 1) the total area covered on the shelter by the different materials, 2) the amount of radiation the crew members receive, and 3) the amount of time for setting up the habitat during specific points in a mission given an event occurs.

  1. Thyroid Echography-induced Thyroid Storm and Exacerbation of Acute Heart Failure.

    Science.gov (United States)

    Nakabayashi, Keisuke; Nakazawa, Naomi; Suzuki, Toshiaki; Asano, Ryotaro; Saito, Hideki; Nomura, Hidekimi; Isomura, Daichi; Okada, Hisayuki; Sugiura, Ryo; Oka, Toshiaki

    2016-01-01

    Hyperthyroidism and thyroid storm affect cardiac circulation in some conditions. Several factors including trauma can induce thyroid storms. We herein describe the case of a 57-year-old woman who experienced a thyroid storm and exacerbation of acute heart failure on thyroid echography. She initially demonstrated a good clinical course after medical rate control for atrial fibrillation; however, thyroid echography for evaluating hyperthyroidism led to a thyroid storm and she collapsed. A multidisciplinary approach stabilized her thyroid hormone levels and hemodynamics. Thus, the medical staff should be prepared for a deterioration in the patient's condition during thyroid echography in heart failure patients with hyperthyroidism.

  2. Origin of solar radio waves

    International Nuclear Information System (INIS)

    Olmr, J.

    1977-01-01

    Solar radiowave radiation amounts to about 10 -7 of the total solar radiation. The solar atmosphere emits radiation of different wavelengths from a fraction of nanometer to kilometer waves. The solar radiowaves are of thermal origin and except for neutral hydrogen emission and solid body radio emission their emission always results from free electrons. The radiowave radiation active components were classified in several types, such as noise storms, flashes, flares, continuum, and flashes lasting for several minutes. The respective types are discussed and their origins shown. The mechanisms are described permitting the formation of radio waves of nonthermal origin, i.e., plasma oscillations, gyromagnetic emission, synchrotron and Cherenkov radiations. (J.P.)

  3. Solar filament impact on 21 January 2005: Geospace consequences

    Science.gov (United States)

    Kozyra, J. U.; Liemohn, M. W.; Cattell, C.; De Zeeuw, D.; Escoubet, C. P.; Evans, D. S.; Fang, X.; Fok, M.-C.; Frey, H. U.; Gonzalez, W. D.; Hairston, M.; Heelis, R.; Lu, G.; Manchester, W. B.; Mende, S.; Paxton, L. J.; Rastaetter, L.; Ridley, A.; Sandanger, M.; Soraas, F.; Sotirelis, T.; Thomsen, M. W.; Tsurutani, B. T.; Verkhoglyadova, O.

    2014-07-01

    On 21 January 2005, a moderate magnetic storm produced a number of anomalous features, some seen more typically during superstorms. The aim of this study is to establish the differences in the space environment from what we expect (and normally observe) for a storm of this intensity, which make it behave in some ways like a superstorm. The storm was driven by one of the fastest interplanetary coronal mass ejections in solar cycle 23, containing a piece of the dense erupting solar filament material. The momentum of the massive solar filament caused it to push its way through the flux rope as the interplanetary coronal mass ejection decelerated moving toward 1 AU creating the appearance of an eroded flux rope (see companion paper by Manchester et al. (2014)) and, in this case, limiting the intensity of the resulting geomagnetic storm. On impact, the solar filament further disrupted the partial ring current shielding in existence at the time, creating a brief superfountain in the equatorial ionosphere—an unusual occurrence for a moderate storm. Within 1 h after impact, a cold dense plasma sheet (CDPS) formed out of the filament material. As the interplanetary magnetic field (IMF) rotated from obliquely to more purely northward, the magnetotail transformed from an open to a closed configuration and the CDPS evolved from warmer to cooler temperatures. Plasma sheet densities reached tens per cubic centimeter along the flanks—high enough to inflate the magnetotail in the simulation under northward IMF conditions despite the cool temperatures. Observational evidence for this stretching was provided by a corresponding expansion and intensification of both the auroral oval and ring current precipitation zones linked to magnetotail stretching by field line curvature scattering. Strong Joule heating in the cusps, a by-product of the CDPS formation process, contributed to an equatorward neutral wind surge that reached low latitudes within 1-2 h and intensified the

  4. Thyroid storm complicated by bicytopenia and disseminated intravascular coagulation.

    Science.gov (United States)

    Tokushima, Yoshinori; Sakanishi, Yuta; Nagae, Kou; Tokushima, Midori; Tago, Masaki; Tomonaga, Motosuke; Yoshioka, Tsuneaki; Hyakutake, Masaki; Sugioka, Takashi; Yamashita, Shu-ichi

    2014-07-24

    Male, 23. Thyroid storm. Delirium • diarrhea • fever • hypertension • hyperventilation • tachycardia • weight loss. -. -. Endocrinology and Metabolic. Unusual clinical course. The clinical presentation of thyroid storm includes fever, tachycardia, hypertension, and neurological abnormalities. It is a serious condition with a high mortality rate. Furthermore, some other complications affect the clinical course of thyroid storm. Although it is reported that prognosis is poor when thyroid storm is complicated by disseminated intravascular coagulation syndrome (DIC) and leukopenia, reports of such cases are rare. A 23-year-old man presented with delirium, high pyrexia, diarrhea, and weight loss of 18 kg over 2 months. According to the criteria of Burch and Wartofsky, he was diagnosed with thyroid storm on the basis of his symptom-complex and laboratory data that confirmed the presence of hyperthyroidism. Investigations also found leukopenia, thrombocytopenia, and disseminated intravascular coagulation, all of which are very rare complications of thyroid storm. We successfully treated him with combined therapy including anti-thyroid medication, despite leukopenia. Early diagnosis and treatment are essential in ensuring a good outcome for patients with this rare combination of medical problems.

  5. Verification of high-speed solar wind stream forecasts using operational solar wind models

    DEFF Research Database (Denmark)

    Reiss, Martin A.; Temmer, Manuela; Veronig, Astrid M.

    2016-01-01

    and the background solar wind conditions. We found that both solar wind models are capable of predicting the large-scale features of the observed solar wind speed (root-mean-square error, RMSE ≈100 km/s) but tend to either overestimate (ESWF) or underestimate (WSA) the number of high-speed solar wind streams (threat......High-speed solar wind streams emanating from coronal holes are frequently impinging on the Earth's magnetosphere causing recurrent, medium-level geomagnetic storm activity. Modeling high-speed solar wind streams is thus an essential element of successful space weather forecasting. Here we evaluate...... high-speed stream forecasts made by the empirical solar wind forecast (ESWF) and the semiempirical Wang-Sheeley-Arge (WSA) model based on the in situ plasma measurements from the Advanced Composition Explorer (ACE) spacecraft for the years 2011 to 2014. While the ESWF makes use of an empirical relation...

  6. A Study of the Solar Wind-Magnetosphere Coupling Using Neural Networks

    Science.gov (United States)

    Wu, Jian-Guo; Lundstedt, Henrik

    1996-12-01

    The interaction between solar wind plasma and interplanetary magnetic field (IMF) and Earth's magnetosphere induces geomagnetic activity. Geomagnetic storms can cause many adverse effects on technical systems in space and on the Earth. It is therefore of great significance to accurately predict geomagnetic activity so as to minimize the amount of disruption to these operational systems and to allow them to work as efficiently as possible. Dynamic neural networks are powerful in modeling the dynamics encoded in time series of data. In this study, we use partially recurrent neural networks to study the solar wind-magnetosphere coupling by predicting geomagnetic storms (as measured by the Dstindex) from solar wind measurements. The solar wind, the IMF and the geomagnetic index Dst data are hourly averaged and read from the National Space Science Data Center's OMNI database. We selected these data from the period 1963 to 1992, which cover 10552h and contain storm time periods 9552h and quiet time periods 1000h. The data are then categorized into three data sets: a training set (6634h), across-validation set (1962h), and a test set (1956h). The validation set is used to determine where the training should be stopped whereas the test set is used for neural networks to get the generalization capability (the out-of-sample performance). Based on the correlation analysis between the Dst index and various solar wind parameters (including various combinations of solar wind parameters), the best coupling functions can be found from the out-of-sample performance of trained neural networks. The coupling functions found are then used to forecast geomagnetic storms one to several hours in advance. The comparisons are made on iterating the single-step prediction several times and on making a non iterated, direct prediction. Thus, we will present the best solar wind-magnetosphere coupling functions and the corresponding prediction results. Interesting Links: Lund Space Weather and AI

  7. Geomagnetically Induced Currents Around the World During the 17 March 2015 Storm

    Science.gov (United States)

    Carter, B. A.; Yizengaw, E.; Pradipta, R.; Weygand, J. M.; Piersanti, M.; Pulkkinen, Antti Aleksi; Moldwin, M. B.; Norman, R.; Zhang, K.

    2016-01-01

    Geomagnetically induced currents (GICs) represent a significant space weather issue for power grid and pipeline infrastructure, particularly during severe geomagnetic storms. In this study, magnetometer data collected from around the world are analyzed to investigate the GICs caused by the 2015 St. Patricks Day storm. While significant GIC activity in the high-latitude regions due to storm time substorm activity is shown for this event, enhanced GIC activity was also measured at two equatorial stations in the American and Southeast Asian sectors. This equatorial GIC activity is closely examined, and it is shown that it is present both during the arrival of the interplanetary shock at the storm sudden commencement (SSC) in Southeast Asia and during the main phase of the storm approximately 10 h later in South America. The SSC caused magnetic field variations at the equator in Southeast Asia that were twice the magnitude of those observed only a few degrees to the north, strongly indicating that the equatorial electrojet (EEJ) played a significant role. The large equatorial magnetic field variations measured in South America are also examined, and the coincident solar wind data are used to investigate the causes of the sudden changes in the EEJ approximately 10 h into the storm. From this analysis it is concluded that sudden magnetopause current increases due to increases in the solarwind dynamic pressure, and the sudden changes in the resultant magnetospheric and ionospheric current systems, are the primary drivers of equatorial GICs.

  8. Thermospheric mass density variations during geomagnetic storms and a prediction model based on the merging electric field

    Science.gov (United States)

    Liu, R.; Lühr, H.; Doornbos, E.; Ma, S.-Y.

    2010-09-01

    With the help of four years (2002-2005) of CHAMP accelerometer data we have investigated the dependence of low and mid latitude thermospheric density on the merging electric field, Em, during major magnetic storms. Altogether 30 intensive storm events (Dstmineffect in order to obtain good results for magnetic storms of all activity levels. The memory effect of the thermosphere is accounted for by a weighted integration of Em over the past 3 h. In addition, a lag time of the mass density response to solar wind input of 0 to 4.5 h depending on latitude and local time is considered. A linear model using the preconditioned color: #000;">Em as main controlling parameter for predicting mass density changes during magnetic storms is developed: ρ=0.5 color: #000;">Em + ρamb, where ρamb is based on the mean density during the quiet day before the storm. We show that this simple relation predicts all storm-induced mass density variations at CHAMP altitude fairly well especially if orbital averages are considered.

  9. Structural Factors That Affect the Performance of Organic Bulk Heterojunction Solar Cells

    KAUST Repository

    Vandewal, Koen

    2013-08-27

    The performance of polymer:fullerene solar cells is strongly affected by the active layer morphology and polymer microstructure. In this Perspective, we review ongoing research on how structural factors influence the photogeneration and collection of charge carriers as well as charge carrier recombination and the related open-circuit voltage. We aim to highlight unexplored research opportunities and provide some guidelines for the synthesis of new conjugated polymers for high-efficiency solar cells. © 2013 American Chemical Society.

  10. Ionospheric response to a recurrent magnetic storm during an event of High Speed Stream in October 2016.

    Science.gov (United States)

    Nicoli Candido, C. M.; Resende, L.; Becker-Guedes, F.; Batista, I. S.

    2017-12-01

    In this work we investigate the response of the low latitude ionosphere to recurrent geomagnetic activity caused by events of High speed streams (HSSs)/Corotating Interaction Regions (CIRs) during the low descending phase of solar activity in the solar cycle 24. Intense magnetic field regions called Corotating Interaction Regions or CIRs are created by the interaction of fast streams and slow streams ejected by long duration coronal holes in Sun. This interaction leads to an increase in the mean interplanetary magnetic field (IMF) which causes moderate and recurrent geomagnetic activity when interacts with the Earth's magnetosphere. The ionosphere can be affected by these phenomena by several ways, such as an increase (or decrease) of the plasma ionization, intensification of plasma instabilities during post-sunset/post-midnight hours and subsequent development of plasma irregularities/spread-F, as well as occurrence of plasma scintillation. Therefore, we investigate the low latitude ionospheric response during moderate geomagnetic storm associated to an event of High Speed Stream occurred during decreasing phase of solar activity in 2016. An additional ionization increasing is observed in Es layer during the main peak of the geomagnetic storm. We investigate two possible different mechanisms that caused these extras ionization: the role of prompt penetration of interplanetary electric field, IEFEy at equatorial region, and the energetic electrons precipitation on the E and F layers variations. Finally, we used data from Digisondes installed at equatorial region, São Luís, and at conjugate points in Brazilian latitudes, Boa Vista and Cachoeira Paulista. We analyzed the ionospheric parameters such as the critical frequency of F layer, foF2, the F layer peak height, hmF2, the F layer bottomside, h'F, the blanketing frequency of sporadic layer, fbEs, the virtual height of Es layer h'Es and the top frequency of the Es layer ftEs during this event.

  11. The Sheath Transport Observer for the Redistribution of Mass (STORM) Image

    Science.gov (United States)

    Kuntz, Kip; Collier, Michael; Sibeck, David G.; Porter, F. Scott; Carter, J. A.; Cravens, Thomas; Omidi, N.; Robertson, Ina; Sembay, S.; Snowden, Steven L.

    2008-01-01

    All of the solar wind energy that powers magnetospheric processes passes through the magnetosheath and magnetopause. Global images of the magnetosheath and magnetopause boundary layers will resolve longstanding controversy surrounding fundamental phenomena that occur at the magnetopause and provide information needed to improve operational space weather models. Recent developments showing that soft X-rays (0.15-1 keV) result from high charge state solar wind ions undergoing charge exchange recombination through collisions with exospheric neutral atoms has led to the realization that soft X-ray imaging can provide global maps of the high-density shocked solar wind within the magnetosheath and cusps, regions lying between the lower density solar wind and magnetosphere. We discuss an instrument concept called the Sheath Transport Observer for the Redistribution of Mass (STORM), an X-ray imager suitable for simultaneously imaging the dayside magnetosheath, the magnetopause boundary layers, and the cusps.

  12. The Sheath Transport Observer for the Redistribution of Mass (STORM) Imager

    Science.gov (United States)

    Collier, Michael R.; Sibeck, David G.; Porter, F. Scott; Burch, J.; Carter, J. A.; Cravens, Thomas; Kuntz, Kip; Omidi, N.; Read, A.; Robertson, Ina; hide

    2010-01-01

    All of the solar wind energy that powers magnetospheric processes passes through the magnetosheath and magnetopause. Global images of the magnetosheath and magnetopause boundary layers will resolve longstanding controversies surrounding fundamental phenomena that occur at the magnetopause and provide information needed to improve operational space weather models. Recent developments showing that soft X-rays (0.15-1 keV) result from high charge state solar wind ions undergoing charge exchange recombination through collisions with exospheric neutral atoms has led to the realization that soft X-ray imaging can provide global maps of the high-density shocked solar wind within the magnetosheath and cusps, regions lying between the lower density solar wind and magnetosphere. We discuss an instrument concept called the Sheath Transport Observer for the Redistribution of Mass (STORM), an X-ray imager suitable for simultaneously imaging the dayside magnetosheath, the magnetopause boundary layers, and the cusps.

  13. Different magnetospheric modes: solar wind driving and coupling efficiency

    Directory of Open Access Journals (Sweden)

    N. Partamies

    2009-11-01

    Full Text Available This study describes a systematic statistical comparison of isolated non-storm substorms, steady magnetospheric convection (SMC intervals and sawtooth events. The number of events is approximately the same in each group and the data are taken from about the same years to avoid biasing by different solar cycle phase. The very same superposed epoch analysis is performed for each event group to show the characteristics of ground-based indices (AL, PCN, PC potential, particle injection at the geostationary orbit and the solar wind and IMF parameters. We show that the monthly occurrence of sawtooth events and isolated non-stormtime substorms closely follows maxima of the geomagnetic activity at (or close to the equinoxes. The most strongly solar wind driven event type, sawtooth events, is the least efficient in coupling the solar wind energy to the auroral ionosphere, while SMC periods are associated with the highest coupling ratio (AL/EY. Furthermore, solar wind speed seems to play a key role in determining the type of activity in the magnetosphere. Slow solar wind is capable of maintaining steady convection. During fast solar wind streams the magnetosphere responds with loading–unloading cycles, represented by substorms during moderately active conditions and sawtooth events (or other storm-time activations during geomagnetically active conditions.

  14. Relativistic electron acceleration during HILDCAA events: are precursor CIR magnetic storms important?

    Czech Academy of Sciences Publication Activity Database

    Hajra, R.; Tsurutani, B. T.; Echer, E.; Gonzalez, W. D.; Brum, Ch. G. M.; Antunes Vieira, L. E.; Santolík, Ondřej

    2015-01-01

    Roč. 67, Article Number 109 (2015), 109/1-109/11 ISSN 1880-5981 R&D Projects: GA MŠk LH12231 Institutional support: RVO:68378289 Keywords : HILDCAAs * high-speed streams * CIRs * chorus plasma waves * radiation belt * magnetospheric relativistic electrons * solar wind * geomagnetic storms Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.871, year: 2015

  15. Coastal Storm Surge Analysis: Storm Forcing. Report 3. Intermediate Submission No. 1.3

    Science.gov (United States)

    2013-07-01

    The storm surge study considers both tropical storms and extratropical cyclones for determination of return period storm surge elevations. The...Appendix B: Extratropical Cyclone Selection in Support of FEMA Region III Storm Surge Modeling...stations applied in the storm selection process. ............................................. 56  Table B2. Extratropical cyclones selected from the

  16. Study of solar features causing GMSs with 250γ H 400γ

    Indian Academy of Sciences (India)

    The effect of solar features on geospheric conditions leading to geomagnetic storms (GMSs) with planetary index, p ≥ 20 and the range of horizontal component of the Earth's magnetic field such that 250 < < 400 has been investigated using interplanetary magnetic field (IMF), solar wind plasma (SWP) and solar ...

  17. Solar-terrestrial disturbances of June-September 1982, 2

    International Nuclear Information System (INIS)

    Kumagai, Hiroshi; Ohbu, Kouji; Ouchi, Choshichi; Isobe, Takeshi; Hori, Toshihiro; Ouchi, Eiji

    1985-01-01

    The outline of the solar activity during the period from June to September 1982 is given. During this period, several extremely developed active regions appeared on the solar disk and produced severe solar-terrestrial disturbances which we had not experienced since August 1972. In June and July, significant solar activities were brought about by the active regions 3763, 3776, and 3804. These regions frequently produced large flares of the highest class of importances in both Hsub(a) and X-ray intensities. However, the geomagnetic disturbances scarcely developed in June. The 3B/X7 flare on July 12 occurred in the region 3804 and caused the largest proton event and geomagnetic storm in this solar cycle. In August and September, flare occurrences were fewer than before. The 2B/M6 and 3N/M4 flares occurred in the region 3886 on September 4, and 2B/C9 flare occurred in the region 3907 on September 19. They are considered to cause two major geomagnetic storms which started on September 5 and 21, respectively. It seems remarkable that significant flares which occurred during these periods were produced by the same active region maintaining activities for more than ten solar rotations; 3776, 3804, and 3886 belonged to the same region in different solar rotations. (author)

  18. The SURE House (Solar Decathlon 2015)

    Energy Technology Data Exchange (ETDEWEB)

    Nastasi, John [Stevens Inst. of Technology, Hoboken, NJ (United States); May, Edwin [Stevens Inst. of Technology, Hoboken, NJ (United States)

    2017-02-21

    architecture for New Jersey and beyond. This is what informed the architectural design of the house. Configured about a compact form, thickly insulated and air-sealed walls eliminate thermal bridging and minimize energy losses while advanced glazing brings in free solar heat during the winter months. As a result of these passive design strategies, the SURE HOUSE has a greatly reduced carbon footprint requiring 91% less energy than a typical New Jersey home. Photovoltaic (PV) arrays on both the rooftop and operable shutters easily provide energy in excess of the home’s modest demands. The Stevens team considers a truly sustainable home in the era of climate change, one that prioritizes low energy use, and integrates right-sized renewable generation to supply the home’s needs. Low consumption, low production. RESILIENT In October of 2012, Hurricane Sandy wreaked havoc along the east coast of the US. In New Jersey alone there was an estimated 29.4 billion dollars in damages, 346,000 homes affected, and almost two and a half million people left without power, in some cases for over 10 days. Recovery from this storm and associated flooding is ongoing to this day, as many New Jersey homeowners grapple with the large costs of rebuilding and struggle to adapt to complicated new home building regulations. Damage from this storm to Hoboken, the home of the Stevens Institute of Technology’s campus, and to the New Jersey shore was extensive and many students on the SURE HOUSE team were directly affected by this historic event. The Stevens design team recognizes that in a world of more frequent and stronger storms, the ability to absorb and adapt to change is more important than ever. Successfully weathering the next storm and its aftermath is one of the primary goals in the design of the SURE HOUSE prototype. The SURE HOUSE introduces unique ‘dry flood-proofing’ methods to residential construction. Innovative wall and floor flood-proofing, utilizing durable composite sheathing

  19. Decreasing the stable trapping region during geomagnetic storm

    International Nuclear Information System (INIS)

    Mal'tsev, Yu.P.; Feshchenko, E.Yu.

    1998-01-01

    Within the frameworks of the magnetic field model, depending on the solar wind pressure, the B = B s (B s is the magnetic field in the undersolar point) contour behaviour in the equatorial plane is calculated. The boundary of stable trapping in the quiet time is at the distance of 10-11 R E by day and ∼ 7 R E by night. During strong storms this distance may be decreased up 4-5 R E . The calculation results coincide satisfactorily with satellite measurements

  20. Structural Factors That Affect the Performance of Organic Bulk Heterojunction Solar Cells

    KAUST Repository

    Vandewal, Koen; Himmelberger, Scott; Salleo, Alberto

    2013-01-01

    The performance of polymer:fullerene solar cells is strongly affected by the active layer morphology and polymer microstructure. In this Perspective, we review ongoing research on how structural factors influence the photogeneration and collection

  1. Grand scheme for solar-terrestrial research

    International Nuclear Information System (INIS)

    Intriligator, D.S.

    1985-01-01

    The study of solar wind and its interaction with magnetic fields and electrical currents is examined. The effects of magnetic storms caused by solar wind interaction with magnetic fields in the magnetosphere and ionosphere are described. The effect of magnetospheric plasma processes on spacecraft operations and the operation of ground-based systems are explained. The development of an International Solar Terrestrial Physics program, which will be designed to place diagnostic experiments on a collection of spacecraft positioned near space is discussed; the components of the program are described

  2. Evaluation of Deep Learning Representations of Spatial Storm Data

    Science.gov (United States)

    Gagne, D. J., II; Haupt, S. E.; Nychka, D. W.

    2017-12-01

    The spatial structure of a severe thunderstorm and its surrounding environment provide useful information about the potential for severe weather hazards, including tornadoes, hail, and high winds. Statistics computed over the area of a storm or from the pre-storm environment can provide descriptive information but fail to capture structural information. Because the storm environment is a complex, high-dimensional space, identifying methods to encode important spatial storm information in a low-dimensional form should aid analysis and prediction of storms by statistical and machine learning models. Principal component analysis (PCA), a more traditional approach, transforms high-dimensional data into a set of linearly uncorrelated, orthogonal components ordered by the amount of variance explained by each component. The burgeoning field of deep learning offers two potential approaches to this problem. Convolutional Neural Networks are a supervised learning method for transforming spatial data into a hierarchical set of feature maps that correspond with relevant combinations of spatial structures in the data. Generative Adversarial Networks (GANs) are an unsupervised deep learning model that uses two neural networks trained against each other to produce encoded representations of spatial data. These different spatial encoding methods were evaluated on the prediction of severe hail for a large set of storm patches extracted from the NCAR convection-allowing ensemble. Each storm patch contains information about storm structure and the near-storm environment. Logistic regression and random forest models were trained using the PCA and GAN encodings of the storm data and were compared against the predictions from a convolutional neural network. All methods showed skill over climatology at predicting the probability of severe hail. However, the verification scores among the methods were very similar and the predictions were highly correlated. Further evaluations are being

  3. Hit by a Perfect Storm? Art & Design in the National Student Survey

    Science.gov (United States)

    Yorke, Mantz; Orr, Susan; Blair, Bernadette

    2014-01-01

    There has long been the suspicion amongst staff in Art & Design that the ratings given to their subject disciplines in the UK's National Student Survey are adversely affected by a combination of circumstances--a "perfect storm". The "perfect storm" proposition is tested by comparing ratings for Art & Design with those…

  4. DE 2 observations of disturbances in the upper atmosphere during a geomagnetic storm

    International Nuclear Information System (INIS)

    Miller, N.J.; Brace, L.H.; Spencer, N.W.; Carignan, G.R.

    1990-01-01

    Data taken in the dusk sector of the mid-latitude thermosphere at 275-450 km by instruments on board Dynamics Explorer 2 in polar orbit are used to examine the response of the ionosphere- thermosphere system during a geomagnetic storm. The results represent the first comparison of nearly simultaneous measurements of storm disturbances in dc electric fields, zonal ion convection, zonal winds, gas composition and temperature, and electron density and temperature, at different seasons in a common local time sector. The storm commenced on November 24, 1982, during the interaction of a solar wind disturbance with the geomagnetic field while the north-south component of the interplanetary magnetic field, B z , was northward. The storm main phase began while B z was turning southward. Storm-induced variations in meridional de electric fields, neutral composition, and N e were stronger and spread farther equatorward in the winter hemisphere. Westward ion convection was intense enough to produce westward winds of 600 m s - 1 via ion drag in the winter hemisphere. Frictional heating was sufficient to elevate ion temperatures above electron temperatures in both seasons and to produce large chemical losses of O + by increasing the rate of O + loss via ion-atom interchange. Part of the chemical loss of O + was compensated by upward flow of O + as the ion scale height adjusted to the increasing ion temperatures. In this storm, frictional heating was an important subauroral heat source equatorward to at least 53 degree invariant latitude

  5. Ionospheric Data Assimilation and Targeted Observation Strategies: Proof of Concept Analysis in a Geomagnetic Storm Event

    Science.gov (United States)

    Kostelich, Eric; Durazo, Juan; Mahalov, Alex

    2017-11-01

    The dynamics of the ionosphere involve complex interactions between the atmosphere, solar wind, cosmic radiation, and Earth's magnetic field. Geomagnetic storms arising from solar activity can perturb these dynamics sufficiently to disrupt radio and satellite communications. Efforts to predict ``space weather,'' including ionospheric dynamics, require the development of a data assimilation system that combines observing systems with appropriate forecast models. This talk will outline a proof-of-concept targeted observation strategy, consisting of the Local Ensemble Transform Kalman Filter, coupled with the Thermosphere Ionosphere Electrodynamics Global Circulation Model, to select optimal locations where additional observations can be made to improve short-term ionospheric forecasts. Initial results using data and forecasts from the geomagnetic storm of 26-27 September 2011 will be described. Work supported by the Air Force Office of Scientific Research (Grant Number FA9550-15-1-0096) and by the National Science Foundation (Grant Number DMS-0940314).

  6. Influence of the interplanetary driver type on the durations of main and recovery phases of magnetic storms

    OpenAIRE

    Yermolaev, Yu. I.; Lodkina, I. G.; Nikolaeva, N. S.; Yermolaev, M. Yu.

    2013-01-01

    We study durations of main and recovery phases of magnetic storms induced by different types of large-scale solar-wind streams (Sheath, magnetic cloud (MC), Ejecta and CIR) on the basis of OMNI data base during 1976-2000. Durations of both main and recovery phases depend on types of interplanetary drivers. On the average, duration of main phase of storms induced by compressed regions (CIR and Sheath) is shorter than by MC and Ejecta while duration of recovery phase of CIR- and Sheath-induced ...

  7. Competition Between Radial Loss and EMIC Wave Scattering of MeV Electrons During Strong CME-shock Driven Storms

    Science.gov (United States)

    Hudson, M. K.; Jaynes, A. N.; Li, Z.; Malaspina, D.; Millan, R. M.; Patel, M.; Qin, M.; Shen, X.; Wiltberger, M. J.

    2017-12-01

    The two strongest storms of Solar Cycle 24, 17 March and 22 June 2015, provide a contrast between magnetospheric response to CME-shocks at equinox and solstice. The 17 March CME-shock initiated storm produced a stronger ring current response with Dst = - 223 nT, while the 22 June CME-shock initiated storm reached a minimum Dst = - 204 nT. The Van Allen Probes ECT instrument measured a dropout in flux for both events which can be characterized by magnetopause loss at higher L values prior to strong recovery1. However, rapid loss is seen at L 3 for the June storm at high energies with maximum drop in the 5.2 MeV channel of the REPT instrument coincident with the observation of EMIC waves in the H+ band by the EMFISIS wave instrument. The rapid time scale of loss can be determined from the 65 minute delay in passage of the Probe A relative to the Probe B spacecraft. The distinct behavior of lower energy electrons at higher L values has been modeled with MHD-test particle simulations, while the rapid loss of higher energy electrons is examined in terms of the minimum resonant energy criterion for EMIC wave scattering, and compared with the timescale for loss due to EMIC wave scattering which has been modeled for other storm events.2 1Baker, D. N., et al. (2016), Highly relativistic radiation belt electron acceleration, transport, and loss: Large solar storm events of March and June 2015, J. Geophys. Res. Space Physics, 121, 6647-6660, doi:10.1002/2016JA022502. 2Li, Z., et al. (2014), Investigation of EMIC wave scattering as the cause for the BARREL 17 January 2013 relativistic electron precipitation event: A quantitative comparison of simulation with observations, Geophys. Res. Lett., 41, 8722-8729, doi:10.1002/2014GL062273.

  8. Geomagnetic storms, super-storms, and their impacts on GPS-based navigation systems

    Science.gov (United States)

    Astafyeva, E.; Yasyukevich, Yu.; Maksikov, A.; Zhivetiev, I.

    2014-07-01

    Using data of GPS receivers located worldwide, we analyze the quality of GPS performance during four geomagnetic storms of different intensity: two super-storms and two intense storms. We show that during super-storms the density of GPS Losses-of-Lock (LoL) increases up to 0.25% at L1 frequency and up to 3% at L2 frequency, and up to 0.15% (at L1) and 1% (at L2) during less intense storms. Also, depending on the intensity of the storm time ionospheric disturbances, the total number of total electron content (TEC) slips can exceed from 4 to 40 times the quiet time level. Both GPS LoL and TEC slips occur during abrupt changes of SYM-H index of geomagnetic activity, i.e., during the main phase of geomagnetic storms and during development of ionospheric storms. The main contribution in the total number of GPS LoL was found to be done by GPS sites located at low and high latitudes, whereas the area of numerous TEC slips seemed to mostly correspond to the boundary of the auroral oval, i.e., region with intensive ionospheric irregularities. Our global maps of TEC slips show where the regions with intense irregularities of electron density occur during geomagnetic storms and will let us in future predict appearance of GPS errors for geomagnetically disturbed conditions.

  9. Developing Local Scale, High Resolution, Data to Interface with Numerical Storm Models

    Science.gov (United States)

    Witkop, R.; Becker, A.; Stempel, P.

    2017-12-01

    High resolution, physical storm models that can rapidly predict storm surge, inundation, rainfall, wind velocity and wave height at the intra-facility scale for any storm affecting Rhode Island have been developed by Researchers at the University of Rhode Island's (URI's) Graduate School of Oceanography (GSO) (Ginis et al., 2017). At the same time, URI's Marine Affairs Department has developed methods that inhere individual geographic points into GSO's models and enable the models to accurately incorporate local scale, high resolution data (Stempel et al., 2017). This combination allows URI's storm models to predict any storm's impacts on individual Rhode Island facilities in near real time. The research presented here determines how a coastal Rhode Island town's critical facility managers (FMs) perceive their assets as being vulnerable to quantifiable hurricane-related forces at the individual facility scale and explores methods to elicit this information from FMs in a format usable for incorporation into URI's storm models.

  10. The influence of solar active region evolution on solar wind streams, coronal hole boundaries and geomagnetic storms

    International Nuclear Information System (INIS)

    Gold, R.E.; Dodson-Prince, H.W.; Hedeman, E.R.; Roelof, E.C.

    1982-01-01

    We have studied solar and interplanetary data by identification of the heliographic longitudes of the coronal source regions of high speed solar wind streams and by mapping the velocities measured near earth back to the sun using the approximation of constant radial velocity. Interplay of active regions and solar wind were studied

  11. Comparison of two recent storm surge events based on results of field surveys

    Science.gov (United States)

    Nakamura, Ryota; Shibayama, Tomoya; Mikami, Takahito; Esteban, Miguel; Takagi, Hiroshi; Maell, Martin; Iwamoto, Takumu

    2017-10-01

    This paper compares two different types of storm surge disaster based on field surveys. Two cases: a severe storm surge flood with its height of over 5 m due to Typhoon Haiyan (2013) in Philippine, and inundation of storm surge around Nemuro city in Hokkaido of Japan with its maximum surge height of 2.8 m caused by extra-tropical cyclone are taken as examples. For the case of the Typhoon Haiyan, buildings located in coastal region were severely affected due to a rapidly increase in ocean surface. The non-engineering buildings were partially or completely destroyed due to their debris transported to an inner bay region. In fact, several previous reports indicated two unique features, bore-like wave and remarkably high speed currents. These characteristics of the storm surge may contribute to a wide-spread corruption for the buildings around the affected region. Furthermore, in the region where the surge height was nearly 3 m, the wooden houses were completely or partially destroyed. On the other hand, in Nemuro city, a degree of suffering in human and facility caused by the storm surge is minor. There was almost no partially destroyed residential houses even though the height of storm surge reached nearly 2.8 m. An observation in the tide station in Nemuro indicated that this was a usual type of storm surge, which showed a gradual increase of sea level height in several hours without possessing the unique characteristics like Typhoon Haiyan. As a result, not only the height of storm surge but also the robustness of the buildings and characteristics of storm surge, such as bore like wave and strong currents, determined the existent of devastation in coastal regions.

  12. Different parameter and technique affecting the rate of evaporation on active solar still -a review

    Science.gov (United States)

    A, Muthu Manokar; D, Prince Winston; A. E, Kabeel; Sathyamurthy, Ravishankar; T, Arunkumar

    2018-03-01

    Water is one of the essential sources for the endurance of human on the earth. As earth having only a small amount of water resources for consumption purpose people in rural and urban areas are getting affected by consuming dirty water that leads to water-borne diseases. Even though ground water is available in small quantity, it has to be treated properly before its use for internal consumption. Brackish water contains dissolve and undissolved contents, and hence it is not suitable for the household purpose. Nowadays, distillation process is done by using passive and active solar stills. The major problem in using passive solar still is meeting higher demand for fresh water. The fresh water production from passive solar still is critically low to meet the demand. To improve the productivity of conventional solar still, input feed water is preheated by integrating the solar still to different collector panels. In this review article, the different parameters that affect the rate of evaporation in an active solar still and the different methods incorporated has been presented. In addition to active distillation system, forced convection technique can be incorporated to increase the yield of fresh water by decreasing the temperature of cover. Furthermore, it is identified that the yield of fresh water from the active desalination system can be improved by sensible and latent heat energy storage. This review will motivate the researchers to decide appropriate active solar still technology for promoting development.

  13. Representation of Northern Hemisphere winter storm tracks in climate models

    Energy Technology Data Exchange (ETDEWEB)

    Greeves, C.Z.; Pope, V.D.; Stratton, R.A.; Martin, G.M. [Met Office Hadley Centre for Climate Prediction and Research, Exeter (United Kingdom)

    2007-06-15

    Northern Hemisphere winter storm tracks are a key element of the winter weather and climate at mid-latitudes. Before projections of climate change are made for these regions, it is necessary to be sure that climate models are able to reproduce the main features of observed storm tracks. The simulated storm tracks are assessed for a variety of Hadley Centre models and are shown to be well modelled on the whole. The atmosphere-only model with the semi-Lagrangian dynamical core produces generally more realistic storm tracks than the model with the Eulerian dynamical core, provided the horizontal resolution is high enough. The two models respond in different ways to changes in horizontal resolution: the model with the semi-Lagrangian dynamical core has much reduced frequency and strength of cyclonic features at lower resolution due to reduced transient eddy kinetic energy. The model with Eulerian dynamical core displays much smaller changes in frequency and strength of features with changes in horizontal resolution, but the location of the storm tracks as well as secondary development are sensitive to resolution. Coupling the atmosphere-only model (with semi-Lagrangian dynamical core) to an ocean model seems to affect the storm tracks largely via errors in the tropical representation. For instance a cold SST bias in the Pacific and a lack of ENSO variability lead to large changes in the Pacific storm track. Extratropical SST biases appear to have a more localised effect on the storm tracks. (orig.)

  14. Effect of solar flare on the equatorial electrojet in eastern Brazil region

    Indian Academy of Sciences (India)

    R G Rastogi

    2017-06-07

    Jun 7, 2017 ... The effect of solar flare, sudden commencement of magnetic storm and of the disturbances ring current on the ... and measured east of geographic north. The ΔH .... Figure 2 shows the intensity of solar x-ray radiations in the ...

  15. Proxy records of Holocene storm events in coastal barrier systems: Storm-wave induced markers

    Science.gov (United States)

    Goslin, Jérôme; Clemmensen, Lars B.

    2017-10-01

    Extreme storm events in the coastal zone are one of the main forcing agents of short-term coastal system behavior. As such, storms represent a major threat to human activities concentrated along the coasts worldwide. In order to better understand the frequency of extreme events like storms, climate science must rely on longer-time records than the century-scale records of instrumental weather data. Proxy records of storm-wave or storm-wind induced activity in coastal barrier systems deposits have been widely used worldwide in recent years to document past storm events during the last millennia. This review provides a detailed state-of-the-art compilation of the proxies available from coastal barrier systems to reconstruct Holocene storm chronologies (paleotempestology). The present paper aims (I) to describe the erosional and depositional processes caused by storm-wave action in barrier and back-barrier systems (i.e. beach ridges, storm scarps and washover deposits), (ii) to understand how storm records can be extracted from barrier and back-barrier sedimentary bodies using stratigraphical, sedimentological, micro-paleontological and geochemical proxies and (iii) to show how to obtain chronological control on past storm events recorded in the sedimentary successions. The challenges that paleotempestology studies still face in the reconstruction of representative and reliable storm-chronologies using these various proxies are discussed, and future research prospects are outlined.

  16. Total electron content responses to HILDCAAs and geomagnetic storms over South America

    Science.gov (United States)

    Mara de Siqueira Negreti, Patricia; Rodrigues de Paula, Eurico; Nicoli Candido, Claudia Maria

    2017-12-01

    Total electron content (TEC) is extensively used to monitor the ionospheric behavior under geomagnetically quiet and disturbed conditions. This subject is of greatest importance for space weather applications. Under disturbed conditions the two main sources of electric fields, which are responsible for changes in the plasma drifts and for current perturbations, are the short-lived prompt penetration electric fields (PPEFs) and the longer-lasting ionospheric disturbance dynamo (DD) electric fields. Both mechanisms modulate the TEC around the globe and the equatorial ionization anomaly (EIA) at low latitudes. In this work we computed vertical absolute TEC over the low latitude of South America. The analysis was performed considering HILDCAA (high-intensity, long-duration, continuous auroral electrojet (AE) activity) events and geomagnetic storms. The characteristics of storm-time TEC and HILDCAA-associated TEC will be presented and discussed. For both case studies presented in this work (March and August 2013) the HILDCAA event follows a geomagnetic storm, and then a global scenario of geomagnetic disturbances will be discussed. Solar wind parameters, geomagnetic indices, O / N2 ratios retrieved by GUVI instrument onboard the TIMED satellite and TEC observations will be analyzed and discussed. Data from the RBMC/IBGE (Brazil) and IGS GNSS networks were used to calculate TEC over South America. We show that a HILDCAA event may generate larger TEC differences compared to the TEC observed during the main phase of the precedent geomagnetic storm; thus, a HILDCAA event may be more effective for ionospheric response in comparison to moderate geomagnetic storms, considering the seasonal conditions. During the August HILDCAA event, TEC enhancements from ˜ 25 to 80 % (compared to quiet time) were observed. These enhancements are much higher than the quiet-time variability observed in the ionosphere. We show that ionosphere is quite sensitive to solar wind forcing and

  17. Watershed Evaluation and Habitat Response to Recent Storms : Annual Report for 1998.

    Energy Technology Data Exchange (ETDEWEB)

    Rhodes, Jonathan J.; Huntington, Charles W.

    1999-01-01

    Large and powerful storm systems moved through the Pacific Northwest during the wet season of 1995-96, triggering widespread flooding, mass erosion, and, possibly altering salmon habitats in affected watersheds. This project study was initiated to assess whether watershed conditions are causing damage, triggered by storm events, to salmon habitat on public lands in the Snake River basin.

  18. Meteorological aspects associated with dust storms in the Sistan region, southeastern Iran

    Science.gov (United States)

    Kaskaoutis, D. G.; Rashki, A.; Houssos, E. E.; Mofidi, A.; Goto, D.; Bartzokas, A.; Francois, P.; Legrand, M.

    2015-07-01

    Dust storms are considered natural hazards that seriously affect atmospheric conditions, ecosystems and human health. A key requirement for investigating the dust life cycle is the analysis of the meteorological (synoptic and dynamic) processes that control dust emission, uplift and transport. The present work focuses on examining the synoptic and dynamic meteorological conditions associated with dust-storms in the Sistan region, southeastern Iran during the summer season (June-September) of the years 2001-2012. The dust-storm days (total number of 356) are related to visibility records below 1 km at Zabol meteorological station, located near to the dust source. RegCM4 model simulations indicate that the intense northern Levar wind, the high surface heating and the valley-like characteristics of the region strongly affect the meteorological dynamics and the formation of a low-level jet that are strongly linked with dust exposures. The intra-annual evolution of the dust storms does not seem to be significantly associated with El-Nino Southern Oscillation, despite the fact that most of the dust-storms are related to positive values of Oceanic Nino Index. National Center for Environmental Prediction/National Center for Atmospheric Research reanalysis suggests that the dust storms are associated with low sea-level pressure conditions over the whole south Asia, while at 700 hPa level a trough of low geopotential heights over India along with a ridge over Arabia and central Iran is the common scenario. A significant finding is that the dust storms over Sistan are found to be associated with a pronounced increase of the anticyclone over the Caspian Sea, enhancing the west-to-east pressure gradient and, therefore, the blowing of Levar. Infrared Difference Dust Index values highlight the intensity of the Sistan dust storms, while the SPRINTARS model simulates the dust loading and concentration reasonably well, since the dust storms are usually associated with peaks in model

  19. Solar weather monitoring

    Directory of Open Access Journals (Sweden)

    J.-F. Hochedez

    2005-11-01

    Full Text Available Space Weather nowcasting and forecasting require solar observations because geoeffective disturbances can arise from three types of solar phenomena: coronal mass ejections (CMEs, flares and coronal holes. For each, we discuss their definition and review their precursors in terms of remote sensing and in-situ observations. The objectives of Space Weather require some specific instrumental features, which we list using the experience gained from the daily operations of the Solar Influences Data analysis Centre (SIDC at the Royal Observatory of Belgium. Nowcasting requires real-time monitoring to assess quickly and reliably the severity of any potentially geoeffective solar event. Both research and forecasting could incorporate more observations in order to feed case studies and data assimilation respectively. Numerical models will result in better predictions of geomagnetic storms and solar energetic particle (SEP events. We review the data types available to monitor solar activity and interplanetary conditions. They come from space missions and ground observatories and range from sequences of dopplergrams, magnetograms, white-light, chromospheric, coronal, coronagraphic and radio images, to irradiance and in-situ time-series. Their role is summarized together with indications about current and future solar monitoring instruments.

  20. Ring current and auroral electrojets in connection with interplanetary medium parameters during magnetic storm

    Directory of Open Access Journals (Sweden)

    Y. I. Feldstein

    1994-06-01

    Full Text Available The relationship between the auroral electrojet indices (AE and the ring current magnetic field (DR was investigated by observations obtained during the magnetic storm on 1-3 April 1973. During the storm main phase the DR development is accompanied by a shift of the auroral electrojets toward the equator. As a result, the standard AE indices calculated on the basis of data from auroral observatories was substantially lower than the real values (AE'. To determine AE' during the course of a storm main phase data from subauroral magnetic observatories should be used. It is shown that the intensity of the indices (AE' which take into account the shift of the electrojets is increased substantially relative to the standard indices during the storm main phase. AE' values are closely correlated with geoeffective solar wind parameters. A high correlation was obtained between AE' and the energy flux into the ring current during the storm main phase. Analysis of magnetic field variations during intervals with intense southward IMF components demonstrates a decrease of the saturation effect of auroral electrojet currents if subauroral stations magnetic field variations are taken into account. This applies both to case studies and statistical data. The dynamics of the electrojets in connection with the development of the ring current and of magnetospheric substorms can be described by the presence (absence of saturation for minimum (maximum AE index values during a 1-h interval. The ring current magnetic field asymmetry (ASY was calculated as the difference between the maximum and minimum field values along a parallel of latitude at low latitudes. The ASY value is closely correlated with geoeffective solar wind parameters and simultaneously is a more sensitive indicator of IMF Bz variations than the symmetric ring current. ASY increases (decreases faster during the main phase (the recovery phase than DR. The magnetic field decay at low latitudes in the

  1. Statistical analysis of storm-time near-Earth current systems

    Directory of Open Access Journals (Sweden)

    M. W. Liemohn

    2015-08-01

    Full Text Available Currents from the Hot Electron and Ion Drift Integrator (HEIDI inner magnetospheric model results for all of the 90 intense storms (disturbance storm-time (Dst minimum < −100 nT from solar cycle 23 (1996–2005 are calculated, presented, and analyzed. We have categorized these currents into the various systems that exist in near-Earth space, specifically the eastward and westward symmetric ring current, the partial ring current, the banana current, and the tail current. The current results from each run set are combined by a normalized superposed epoch analysis technique that scales the timeline of each phase of each storm before summing the results. It is found that there is a systematic ordering to the current systems, with the asymmetric current systems peaking during storm main phase (tail current rising first, then the banana current, followed by the partial ring current and the symmetric current systems peaking during the early recovery phase (westward and eastward symmetric ring current having simultaneous maxima. The median and mean peak amplitudes for the current systems ranged from 1 to 3 MA, depending on the setup configuration used in HEIDI, except for the eastward symmetric ring current, for which the mean never exceeded 0.3 MA for any HEIDI setup. The self-consistent electric field description in HEIDI yielded larger tail and banana currents than the Volland–Stern electric field, while the partial and symmetric ring currents had similar peak values between the two applied electric field models.

  2. Thyroid storm and warm autoimmune hemolytic anemia.

    Science.gov (United States)

    Moore, Joseph A; Gliga, Louise; Nagalla, Srikanth

    2017-08-01

    Graves' disease is often associated with other autoimmune disorders, including rare associations with autoimmune hemolytic anemia (AIHA). We describe a unique presentation of thyroid storm and warm AIHA diagnosed concurrently in a young female with hyperthyroidism. The patient presented with nausea, vomiting, diarrhea and altered mental status. Laboratory studies revealed hemoglobin 3.9g/dL, platelets 171×10 9 L -1 , haptoglobin storm and warm AIHA. She was started on glucocorticoids to treat both warm AIHA and thyroid storm, as well as antithyroid medications, propranolol and folic acid. Due to profound anemia and hemodynamic instability, the patient was transfused two units of uncrossmatched packed red blood cells slowly and tolerated this well. She was discharged on methimazole as well as a prolonged prednisone taper, and achieved complete resolution of the thyrotoxicosis and anemia at one month. Hyperthyroidism can affect all three blood cell lineages of the hematopoietic system. Anemia can be seen in 10-20% of patients with thyrotoxicosis. Several autoimmune processes can lead to anemia in Graves' disease, including pernicious anemia, celiac disease, and warm AIHA. This case illustrates a rarely described presentation of a patient with Graves' disease presenting with concurrent thyroid storm and warm AIHA. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. CAWSES November 7-8, 2004, Superstorm: Complex Solar and Interplanetary Features in the Post-Solar Maximum Phase

    Science.gov (United States)

    Tsurutani, Bruce T.; Echer, Ezequiel; Guarnieri, Fernando L.; Kozyra, J. U.

    2008-01-01

    The complex interplanetary structures during 7 to 8 Nov 2004 are analyzed to identify their properties as well as resultant geomagnetic effects and the solar origins. Three fast forward shocks, three directional discontinuities and two reverse waves were detected and analyzed in detail. The three fast forward shocks 'pump' up the interplanetary magnetic field from a value of approx.4 nT to 44 nT. However, the fields after the shocks were northward, and magnetic storms did not result. The three ram pressure increases were associated with major sudden impulses (SI + s) at Earth. A magnetic cloud followed the third forward shock and the southward Bz associated with the latter was responsible for the superstorm. Two reverse waves were detected, one at the edge and one near the center of the magnetic cloud (MC). It is suspected that these 'waves' were once reverse shocks which were becoming evanescent when they propagated into the low plasma beta MC. The second reverse wave caused a decrease in the southward component of the IMF and initiated the storm recovery phase. It is determined that flares located at large longitudinal distances from the subsolar point were the most likely causes of the first two shocks without associated magnetic clouds. It is thus unlikely that the shocks were 'blast waves' or that magnetic reconnection eroded away the two associated MCs. This interplanetary/solar event is an example of the extremely complex magnetic storms which can occur in the post-solar maximum phase.

  4. Clustering of European winter storms: A multi-model perspective

    Science.gov (United States)

    Renggli, Dominik; Buettner, Annemarie; Scherb, Anke; Straub, Daniel; Zimmerli, Peter

    2016-04-01

    The storm series over Europe in 1990 (Daria, Vivian, Wiebke, Herta) and 1999 (Anatol, Lothar, Martin) are very well known. Such clusters of severe events strongly affect the seasonally accumulated damage statistics. The (re)insurance industry has quantified clustering by using distribution assumptions deduced from the historical storm activity of the last 30 to 40 years. The use of storm series simulated by climate models has only started recently. Climate model runs can potentially represent 100s to 1000s of years, allowing a more detailed quantification of clustering than the history of the last few decades. However, it is unknown how sensitive the representation of clustering is to systematic biases. Using a multi-model ensemble allows quantifying that uncertainty. This work uses CMIP5 decadal ensemble hindcasts to study clustering of European winter storms from a multi-model perspective. An objective identification algorithm extracts winter storms (September to April) in the gridded 6-hourly wind data. Since the skill of European storm predictions is very limited on the decadal scale, the different hindcast runs are interpreted as independent realizations. As a consequence, the available hindcast ensemble represents several 1000 simulated storm seasons. The seasonal clustering of winter storms is quantified using the dispersion coefficient. The benchmark for the decadal prediction models is the 20th Century Reanalysis. The decadal prediction models are able to reproduce typical features of the clustering characteristics observed in the reanalysis data. Clustering occurs in all analyzed models over the North Atlantic and European region, in particular over Great Britain and Scandinavia as well as over Iberia (i.e. the exit regions of the North Atlantic storm track). Clustering is generally weaker in the models compared to reanalysis, although the differences between different models are substantial. In contrast to existing studies, clustering is driven by weak

  5. Storm-surge flooding on the Yukon-Kuskokwim Delta, Alaska

    Science.gov (United States)

    Terenzi, John; Ely, Craig R.; Jorgenson, M. Torre

    2014-01-01

    Coastal regions of Alaska are regularly affected by intense storms of ocean origin, the frequency and intensity of which are expected to increase as a result of global climate change. The Yukon-Kuskokwim Delta (YKD), situated in western Alaska on the eastern edge of the Bering Sea, is one of the largest deltaic systems in North America. Its low relief makes it especially susceptible to storm-driven flood tides and increases in sea level. Little information exists on the extent of flooding caused by storm surges in western Alaska and its effects on salinization, shoreline erosion, permafrost thaw, vegetation, wildlife, and the subsistence-based economy. In this paper, we summarize storm flooding events in the Bering Sea region of western Alaska during 1913 – 2011 and map both the extent of inland flooding caused by autumn storms on the central YKD, using Radarsat-1 and MODIS satellite imagery, and the drift lines, using high-resolution IKONOS satellite imagery and field surveys. The largest storm surges occurred in autumn and were associated with high tides and strong (> 65 km hr-1) southwest winds. Maximum inland extent of flooding from storm surges was 30.3 km in 2005, 27.4 km in 2006, and 32.3 km in 2011, with total flood area covering 47.1%, 32.5%, and 39.4% of the 6730 km2 study area, respectively. Peak stages for the 2005 and 2011 storms were 3.1 m and 3.3 m above mean sea level, respectively—almost as high as the 3.5 m amsl elevation estimated for the largest storm observed (in November 1974). Several historically abandoned village sites lie within the area of inundation of the largest flood events. With projected sea level rise, large storms are expected to become more frequent and cover larger areas, with deleterious effects on freshwater ponds, non-saline habitats, permafrost, and landscapes used by nesting birds and local people.

  6. Mediterranean Storms: An Integrated Approach of Risk Management

    Science.gov (United States)

    Karageorgou, H.; Riza, E.; Linos, A.; Papanikolaou, D.

    2010-09-01

    Disaster by UN definition is "a serious disruption of the functioning of a community or a society, involving widespread human, material, economic, or environmental losses and impacts, which exceeds the ability of the affected community or society to cope using only its own resources". Mediterranean storms induce flash floods caused by excessive amounts of rainfall within a short lasting period of time. The intensity and duration of precipitation, region geomorphology, urbanization and different governmental emergency management structures trigger different consequences between Mediterranean countries. The integrated approach in management of storm risk represents a holistic perspective including interactions between government, science and technology institutions, developing agencies, private sector, NGOs and public. Local authorities and national government are responsible for the design, preparation and decision on storm risk management policies and strategies considering scientific risk identifying, assessing and understanding. Efficient governance management requires satisfied response to early warning systems, functionality of the affected systems upon which society depends and appropriate focus on variable interest, beliefs, values and ideologies between social groups. Also an appropriate balancing of benefits and costs in an efficient and equitable manner is important for the governance risk management. Natural sciences in corporation with the engineering science have developed effective early prediction, warning and monitoring systems on storm and flood risk. The health sciences use prediction systems for health related hazards and consequences and the social sciences research estimates the human resilience during disasters and the factors which affect and determine the human behavior. Also social sciences survey the response of public to early warning messages, the appropriate communicative methods to distributing messages and mechanisms to improve public

  7. Toward an integrated storm surge application: ESA Storm Surge project

    Science.gov (United States)

    Lee, Boram; Donlon, Craig; Arino, Olivier

    2010-05-01

    Storm surges and their associated coastal inundation are major coastal marine hazards, both in tropical and extra-tropical areas. As sea level rises due to climate change, the impact of storm surges and associated extreme flooding may increase in low-lying countries and harbour cities. Of the 33 world cities predicted to have at least 8 million people by 2015, at least 21 of them are coastal including 8 of the 10 largest. They are highly vulnerable to coastal hazards including storm surges. Coastal inundation forecasting and warning systems depend on the crosscutting cooperation of different scientific disciplines and user communities. An integrated approach to storm surge, wave, sea-level and flood forecasting offers an optimal strategy for building improved operational forecasts and warnings capability for coastal inundation. The Earth Observation (EO) information from satellites has demonstrated high potential to enhanced coastal hazard monitoring, analysis, and forecasting; the GOCE geoid data can help calculating accurate positions of tide gauge stations within the GLOSS network. ASAR images has demonstrated usefulness in analysing hydrological situation in coastal zones with timely manner, when hazardous events occur. Wind speed and direction, which is the key parameters for storm surge forecasting and hindcasting, can be derived by using scatterometer data. The current issue is, although great deal of useful EO information and application tools exist, that sufficient user information on EO data availability is missing and that easy access supported by user applications and documentation is highly required. Clear documentation on the user requirements in support of improved storm surge forecasting and risk assessment is also needed at the present. The paper primarily addresses the requirements for data, models/technologies, and operational skills, based on the results from the recent Scientific and Technical Symposium on Storm Surges (www

  8. Dependence of the cross polar cap potential saturation on the type of solar wind streams

    OpenAIRE

    Nikolaeva, N. S.; Yermolaev, Yu. I.; Lodkina, I. G.

    2013-01-01

    We compare of the cross polar cap potential (CPCP) saturation during magnetic storms induced by various types of the solar wind drivers. By using the model of Siscoe-Hill \\citep{Hilletal1976,Siscoeetal2002a,Siscoeetal2002b,Siscoeetal2004,Siscoe2011} we evaluate criteria of the CPCP saturation during the main phases of 257 magnetic storms ($Dst_{min} \\le -50$ nT) induced by the following types of the solar wind streams: magnetic clouds (MC), Ejecta, the compress region Sheath before MC ($Sh_{M...

  9. Substorm activity during the main phase of magnetic storms induced by the CIR and ICME events

    Science.gov (United States)

    Boroyev, R. N.; Vasiliev, M. S.

    2018-01-01

    In this work, the relation of high-latitude indices of geomagnetic activity (AE, Kp) with the rate of storm development and a solar wind electric field during the main phase of magnetic storm induced by the CIR and ICME events is investigated. 72 magnetic storms induced by CIR and ICME events have been selected. It is shown that for the CIR and ICME events the increase of average value of the Kp index (Kpaver) is observed with the growth of rate of storm development. The value of Kpaver index correlates with the magnitude of minimum value of Dst index (|Dstmin|) only for the ICME events. The analysis of average values of AE and Kp indices during the main phase of magnetic storm depending on the SW electric field has shown that for the CIR events, unlike the ICME events, the value of AEaver increases with the growth of average value of the electric field (Eswaver). The value of Kpaver correlates with the Eswaver only for the ICME events. The relation between geomagnetic indices and the maximum value of SW electric field (Eswmax) is weak. However, for the ICME events Kpaver correlates with Eswmax.

  10. Healthcare4VideoStorm: Making Smart Decisions Based on Storm Metrics.

    Science.gov (United States)

    Zhang, Weishan; Duan, Pengcheng; Chen, Xiufeng; Lu, Qinghua

    2016-04-23

    Storm-based stream processing is widely used for real-time large-scale distributed processing. Knowing the run-time status and ensuring performance is critical to providing expected dependability for some applications, e.g., continuous video processing for security surveillance. The existing scheduling strategies' granularity is too coarse to have good performance, and mainly considers network resources without computing resources while scheduling. In this paper, we propose Healthcare4Storm, a framework that finds Storm insights based on Storm metrics to gain knowledge from the health status of an application, finally ending up with smart scheduling decisions. It takes into account both network and computing resources and conducts scheduling at a fine-grained level using tuples instead of topologies. The comprehensive evaluation shows that the proposed framework has good performance and can improve the dependability of the Storm-based applications.

  11. Solar Drift-Pair Bursts

    Science.gov (United States)

    Stanislavsky, A.; Volvach, Ya.; Konovalenko, A.; Koval, A.

    2017-08-01

    In this paper a new sight on the study of solar bursts historically called drift pairs (DPs) is presented. Having a simple morphology on dynamic spectra of radio records (two short components separated in time, and often they are very similar) and discovered at the dawn of radio astronomy, their features remain unexplained totally up to now. Generally, the DPs are observed during the solar storms of type III bursts, but not every storm of type III bursts is linked with DPs. Detected by ground-based instruments at decameter and meter wavelengths, the DP bursts are limited in frequency bandwidth. They can drift from high frequencies to low ones and vice versa. Their frequency drift rate may be both lower and higher than typical rates of type III bursts at the same frequency range. The development of low-frequency radio telescopes and data processing provide additional possibilities in the research. In this context the fresh analysis of DPs, made from recent observations in the summer campaign of 2015, are just considered. Their study was implemented by updated tools of the UTR-2 radio telescope at 9-33 MHz. During 10-12 July of 2015, DPs forming the longest patterns on dynamic spectra are about 7% of the total number of recorded DPs. Their marvelous resemblance in frequency drift rates with the solar S-bursts is discussed.

  12. Geomagnetic Storm Impact On GPS Code Positioning

    Science.gov (United States)

    Uray, Fırat; Varlık, Abdullah; Kalaycı, İbrahim; Öǧütcü, Sermet

    2017-04-01

    This paper deals with the geomagnetic storm impact on GPS code processing with using GIPSY/OASIS research software. 12 IGS stations in mid-latitude were chosen to conduct the experiment. These IGS stations were classified as non-cross correlation receiver reporting P1 and P2 (NONCC-P1P2), non-cross correlation receiver reporting C1 and P2 (NONCC-C1P2) and cross-correlation (CC-C1P2) receiver. In order to keep the code processing consistency between the classified receivers, only P2 code observations from the GPS satellites were processed. Four extreme geomagnetic storms October 2003, day of the year (DOY), 29, 30 Halloween Storm, November 2003, DOY 20, November 2004, DOY 08 and four geomagnetic quiet days in 2005 (DOY 92, 98, 99, 100) were chosen for this study. 24-hour rinex data of the IGS stations were processed epoch-by-epoch basis. In this way, receiver clock and Earth Centered Earth Fixed (ECEF) Cartesian Coordinates were solved for a per-epoch basis for each day. IGS combined broadcast ephemeris file (brdc) were used to partly compensate the ionospheric effect on the P2 code observations. There is no tropospheric model was used for the processing. Jet Propulsion Laboratory Application Technology Satellites (JPL ATS) computed coordinates of the stations were taken as true coordinates. The differences of the computed ECEF coordinates and assumed true coordinates were resolved to topocentric coordinates (north, east, up). Root mean square (RMS) errors for each component were calculated for each day. The results show that two-dimensional and vertical accuracy decreases significantly during the geomagnetic storm days comparing with the geomagnetic quiet days. It is observed that vertical accuracy is much more affected than the horizontal accuracy by geomagnetic storm. Up to 50 meters error in vertical component has been observed in geomagnetic storm day. It is also observed that performance of Klobuchar ionospheric correction parameters during geomagnetic storm

  13. Solar-terrestrial disturbances of June-September 1982, 4

    International Nuclear Information System (INIS)

    Koizumi, Tokuji; Hiidome, Shigeharu; Maeno, Hideo; Oda, Tadashi; Echizenya, Yoshimatsu; Kamishikiryo, Syogo.

    1985-01-01

    As a distinctive feature of the ionosphere observed in 1982, it may be said that the ionospheric disturbances associated with outstanding solar flares occurred frequently, especially that the tendency was remarkable during the period from June to September 1982. First, the feature found is an abnormal increase in fsub(min) on ionograms observed during the period from 4 June to 19 July. Secondly, it contains ionospheric disturbances which appeared in the F-region associated with geomagnetic storms, in the period from 13 to 16 July, from 5 to 8 September and from 21 to 28 September, 1982. Variations in the aspect which ionospheric storms associated with these geomagnetic storms had assumed due to the magnitude of geomagnetic storms, the local time of their occurrence, and their passage were extensively investigated by utilizing data from not only the five Japanese ionospheric stations, but also available eastern Asia, Europe, and so on. The four ionospheric storms investigated had individual characteristics due to the difference among local times of appearance in main phase of geomagnetic storms related to ionospheric storms. The scale of the ionospheric storms associated with a giant geomagnetic storm on July 14 whose drop in horizontal component amounted to 630 nT in its maximum stage was smaller than that on August 4-5, 1972 (359 nT). (author)

  14. New York Solar Smart DG Hub-Resilient Solar Project: Economic and Resiliency Impact of PV and Storage on New York Critical Infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Kate; Burman, Kari; Simpkins, Travis; Helson, Erica; Lisell, Lars, Case, Tria

    2016-06-01

    Resilient PV, which is solar paired with storage ('solar-plus-storage'), provides value both during normal grid operation and power outages as opposed to traditional solar PV, which functions only when the electric grid is operating. During normal grid operations, resilient PV systems help host sites generate revenue and/or reduce electricity bill charges. During grid outages, resilient PV provides critical emergency power that can help people in need and ease demand on emergency fuel supplies. The combination of grid interruptions during recent storms, the proliferation of solar PV, and the growing deployment of battery storage technologies has generated significant interest in using these assets for both economic and resiliency benefits. This report analyzes the technical and economic viability for resilient PV on three critical infrastructure sites in New York City (NYC): a school that is part of a coastal storm shelter system, a fire station, and a NYCHA senior center that serves as a cooling center during heat emergencies. This analysis differs from previous solar-plus-storage studies by placing a monetary value on resiliency and thus, in essence, modeling a new revenue stream for the avoided cost of a power outage. Analysis results show that resilient PV is economically viable for NYC's critical infrastructure and that it may be similarly beneficial to other commercial buildings across the city. This report will help city building owners, managers, and policymakers better understand the economic and resiliency benefits of resilient PV. As NYC fortifies its building stock against future storms of increasing severity, resilient PV can play an important role in disaster response and recovery while also supporting city greenhouse gas emission reduction targets and relieving stress to the electric grid from growing power demands.

  15. Development of VLF noise storm and its relation to dynamics of magnetosphere during geomagnetic storms

    International Nuclear Information System (INIS)

    Fedyakina, N.I.; Khorosheva, O.V.

    1989-01-01

    Dependence between the development of geomagnetic storm and VLF noise storm is studied. Two conditions should be met for the development of noise storm in VLF-hiss (f ≅ 0.5-10 kHz): a) threshold intensity of electron fluxes with E e > 40 keV in plasma layers; b) the presence of substorms resulting to widening of electron belt and its collision with cold plasma of plasmasphere. The noise storm at the fixed longitude begins about midnight independently of the phase of magnetic storm; Noise storm duration is connected with geomagnetic storm intensity by direct linear relationship

  16. Three-Step Buildup of the 17 March 2015 Storm Ring Current: Implication for the Cause of the Unexpected Storm Intensification

    Science.gov (United States)

    Keika, Kunihiro; Seki, Kanako; Nosé, Masahito; Miyoshi, Yoshizumi; Lanzerotti, Louis J.; Mitchell, Donald G.; Gkioulidou, Matina; Manweiler, Jerry W.

    2018-01-01

    We examine the spatiotemporal variations of the energy density and the energy spectral evolution of energetic ions in the inner magnetosphere during the main phase of the 17 March 2015 storm, using data from the RBSPICE and EMFISIS instruments onboard Van Allen Probes. The storm developed in response to two southward IMF intervals separated by about 3 h. In contrast to two steps seen in the Dst/SYM-H index, the ring current ion population evolved in three steps: the first subphase was apparently caused by the earlier southward IMF, and the subsequent subphases occurred during the later southward IMF period. Ion energy ranges that contribute to the ring current differed between the three subphases. We suggest that the spectral evolution resulted from the penetration of different plasma sheet populations. The ring current buildup during the first subphase was caused by the penetration of a relatively low-energy population that had existed in the plasma sheet during a prolonged prestorm northward IMF interval. The deeper penetration of the lower-energy population was responsible for the second subphase. The third subphase, where the storm was unexpectedly intensified to a Dst/SYM-H level of population. We attribute the hot, dense population to the entry of hot, dense solar wind into the plasma sheet and/or ion heating/acceleration in the near-Earth plasma sheet associated with magnetotail activity such as reconnection and dipolarization.

  17. Geomagnetic storm related to intense solar radio burst type II and III ...

    African Journals Online (AJOL)

    The strong energetic particles ejected during sun's activity will propagate towards earth and contribute to solar radio bursts. These solar radio bursts can be detected using CALLISTO system. The open website of the NASA provides us the data including CALLISTO, TESIS, solar monitor, SOHO and space weather. The type ...

  18. Geomagnetic Storm Sudden Commencements

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Storm Sudden Commencements (ssc) 1868 to present: STORM1 and STORM2 Lists: (Some text here is taken from the International Association of Geomagnetism and Aeronomy...

  19. Reconstruction of solar wind features that caused a super geomagnetic storm

    Science.gov (United States)

    Lui, A. T. Y.; Gonzalez, W. D.

    2013-06-01

    A superstorm with Dst < -300 nT can cause major space disturbances. We examine one on March 31, 2001 that has the minimum Dst of -387 nT and obtain two-dimensional maps in pressure and magnetic field of the sheath region and a magnetic cloud behind it. Both the sheath and the magnetic cloud play a role in building the storm strength. Several properties of the magnetic cloud are inferred, including an estimated total magnetic flux of ~6.5×1012 Wb.

  20. Shoreline resilience to individual storms and storm clusters on a meso-macrotidal barred beach

    NARCIS (Netherlands)

    Angnuureng, Donatus Bapentire; Almar, Rafael; Senechal, Nadia; Castelle, Bruno; Addo, Kwasi Appeaning; Marieu, Vincent; Ranasinghe, Roshanka

    2017-01-01

    This study investigates the impact of individual storms and storm clusters on shoreline recovery for the meso-to macrotidal, barred Biscarrosse beach in SW France, using 6 years of daily video observations. While the study area experienced 60 storms during the 6-year study period, only 36 storms

  1. Empirical model for the electron density peak height disturbance in response to solar wind conditions

    Science.gov (United States)

    Blanch, E.; Altadill, D.

    2009-04-01

    Geomagnetic storms disturb the quiet behaviour of the ionosphere, its electron density and the electron density peak height, hmF2. Many works have been done to predict the variations of the electron density but few efforts have been dedicated to predict the variations the hmF2 under disturbed helio-geomagnetic conditions. We present the results of the analyses of the F2 layer peak height disturbances occurred during intense geomagnetic storms for one solar cycle. The results systematically show a significant peak height increase about 2 hours after the beginning of the main phase of the geomagnetic storm, independently of both the local time position of the station at the onset of the storm and the intensity of the storm. An additional uplift is observed in the post sunset sector. The duration of the uplift and the height increase are dependent of the intensity of the geomagnetic storm, the season and the local time position of the station at the onset of the storm. An empirical model has been developed to predict the electron density peak height disturbances in response to solar wind conditions and local time which can be used for nowcasting and forecasting the hmF2 disturbances for the middle latitude ionosphere. This being an important output for EURIPOS project operational purposes.

  2. The effects of storms and storm-generated currents on sand beaches in Southern Maine, USA

    Science.gov (United States)

    Hill, H.W.; Kelley, J.T.; Belknap, D.F.; Dickson, S.M.

    2004-01-01

    Storms are one of the most important controls on the cycle of erosion and accretion on beaches. Current meters placed in shoreface locations of Saco Bay and Wells Embayment, ME, recorded bottom currents during the winter months of 2000 and 2001, while teams of volunteers profiled the topography of nearby beaches. Coupling offshore meteorological and beach profile data made it possible to determine the response of nine beaches in southern Maine to various oceanographic and meteorological conditions. The beaches selected for profiling ranged from pristine to completely developed and permitted further examination of the role of seawalls on the response of beaches to storms. Current meters documented three unique types of storms: frontal passages, southwest storms, and northeast storms. In general, the current meter results indicate that frontal passages and southwest storms were responsible for bringing sediment towards the shore, while northeast storms resulted in a net movement of sediment away from the beach. During the 1999-2000 winter, there were a greater percentage of frontal passages and southwest storms, while during the 2000-2001 winter, there were more northeast storms. The sediment that was transported landward during the 1999-2000 winter was reworked into the berm along moderately and highly developed beaches during the next summer. A northeast storm on March 5-6, 2001, resulted in currents in excess of 1 m s-1 and wave heights that reached six meters. The storm persisted over 10 high tides and caused coastal flooding and property damage. Topographic profiles made before and after the storm demonstrate that developed beaches experienced a loss of sediment volume during the storm, while sediment was redistributed along the profile on moderately developed and undeveloped beaches. Two months after the storm, the profiles along the developed beaches had not reached their pre-storm elevation. In comparison, the moderately developed and undeveloped beaches

  3. Remote sensing of severe convective storms over Qinghai-Xizang Plateau

    Science.gov (United States)

    Hung, R. J.; Liu, J. M.; Tsao, D. Y.; Smith, R. E.

    1984-01-01

    The American satellite, GOES-1 was moved to the Indian Ocean at 58 deg E during the First GARP Global Experiment (FGGE). The Qinghai-Xizang Plateau significantly affects the initiation and development of heavy rainfall and severe storms in China, just as the Rocky Mountains influence the local storms in the United States. Satelite remote sensing of short-lived, meso-scale convective storms is particularly important for covering a huge area of a high elevation with a low population density, such as the Qinghai-Xizang Plateau. Results of this study show that a high growth rate of the convective clouds, followed by a rapid collapse of the cloud top, is associated with heavy rainfall in the area. The tops of the convective clouds developed over the Plateau lie between the altitudes of the two tropopauses, while the tops of convective clouds associated with severe storms in the United States usually extend much above the tropopause.

  4. Shifting Pacific storm tracks as stressors to ecosystems of western North America.

    Science.gov (United States)

    Dannenberg, Matthew P; Wise, Erika K

    2017-11-01

    Much of the precipitation delivered to western North America arrives during the cool season via midlatitude Pacific storm tracks, which may experience future shifts in response to climate change. Here, we assess the sensitivity of the hydroclimate and ecosystems of western North America to the latitudinal position of cool-season Pacific storm tracks. We calculated correlations between storm track variability and three hydroclimatic variables: gridded cool-season standardized precipitation-evapotranspiration index, April snow water equivalent, and water year streamflow from a network of USGS stream gauges. To assess how historical storm track variability affected ecosystem processes, we derived forest growth estimates from a large network of tree-ring widths and land surface phenology and wildfire estimates from remote sensing. From 1980 to 2014, cool-season storm tracks entered western North America between approximately 41°N and 53°N. Cool-season moisture supply and snowpack responded strongly to storm track position, with positive correlations to storm track latitude in eastern Alaska and northwestern Canada but negative correlations in the northwestern U.S. Ecosystems of the western United States were greener and more productive following winters with south-shifted storm tracks, while Canadian ecosystems were greener in years when the cool-season storm track was shifted to the north. On average, larger areas of the northwestern United States were burned by moderate to high severity wildfires when storm tracks were displaced north, and the average burn area per fire also tended to be higher in years with north-shifted storm tracks. These results suggest that projected shifts of Pacific storm tracks over the 21st century would likely alter hydroclimatic and ecological regimes in western North America, particularly in the northwestern United States, where moisture supply and ecosystem processes are highly sensitive to the position of cool-season storm tracks.

  5. Non-photic solar associations of heart rate variability and myocardial infarction

    Science.gov (United States)

    Cornélissen, Germaine; Halberg, Franz; Breus, Tamara; Syutkina, Elena V.; Baevsky, Roman; Weydahl, Andi; Watanabe, Yoshihiko; Otsuka, Kuniaki; Siegelova, Jarmila; Fiser, Bohumil; Bakken, Earl E.

    2002-03-01

    Alignment of serial epidemiological, physiological, including electrocardiographic data with variations in galactic cosmic rays, geomagnetic activity, and atmospheric pressure suggests the possibility of links among these physical environmental variations and health risks, such as myocardial infarctions and ischemic strokes, among others. An increase in the incidence of myocardial infarction in association with magnetic storms, reported by several investigators from Russia, Israel, Italy and Mexico, accounts in Minnesota for a 5% (220cases/year) increase in mortality during years of maximal solar activity by comparison with years of minimal solar activity. Magnetic storms are also found to decrease heart rate variability (HRV), indicating a possible mechanism since a reduced HRV is a prognostic factor for coronary artery disease and myocardial infarction. Longitudinal electrocardiographic monitoring for a week or much longer spans in different geographic locations, notably in the auroral oval, further suggests that the decrease in HRV affects spectral regions other than that around 3.6s (0.15-0.40Hz), reportedly associated with the parasympathetic nervous system. Differences in some associations are observed from solar cycle to solar cycle, and as a function of solar cycle stage, a finding resolving controversies. Coordinated physiological and physical monitoring, the scope of an international project on the Biosphere and the Cosmos, seeks reference values for a better understanding of environmental effects on human health and for testing the merit of space weather reports that could prompt countermeasures in space and on earth. Physiological data being collected systematically worldwide and morbidity/mortality statistics from causes such as myocardial infarction and stroke constitute invaluable data bases for assessing changes within the physiological range, for detecting environmental effects and for recognizing endogenous as well as exogenous disease

  6. Thermospheric mass density variations during geomagnetic storms and a prediction model based on the merging electric field

    Directory of Open Access Journals (Sweden)

    R. Liu

    2010-09-01

    Full Text Available With the help of four years (2002–2005 of CHAMP accelerometer data we have investigated the dependence of low and mid latitude thermospheric density on the merging electric field, Em, during major magnetic storms. Altogether 30 intensive storm events (Dstmin<−100 nT are chosen for a statistical study. In order to achieve a good correlation Em is preconditioned. Contrary to general opinion, Em has to be applied without saturation effect in order to obtain good results for magnetic storms of all activity levels. The memory effect of the thermosphere is accounted for by a weighted integration of Em over the past 3 h. In addition, a lag time of the mass density response to solar wind input of 0 to 4.5 h depending on latitude and local time is considered. A linear model using the preconditioned Em as main controlling parameter for predicting mass density changes during magnetic storms is developed: ρ=0.5 Em + ρamb, where ρamb is based on the mean density during the quiet day before the storm. We show that this simple relation predicts all storm-induced mass density variations at CHAMP altitude fairly well especially if orbital averages are considered.

  7. The influence of solar active region evolution on solar wind streams, coronal hole boundaries and geomagnetic storms

    Science.gov (United States)

    Gold, R. E.; Dodson-Prince, H. W.; Hedeman, E. R.; Roelof, E. C.

    1982-01-01

    Solar and interplanetary data are examined, taking into account the identification of the heliographic longitudes of the coronal source regions of high speed solar wind (SW) streams by Nolte and Roelof (1973). Nolte and Roelof have 'mapped' the velocities measured near earth back to the sun using the approximation of constant radial velocity. The 'Carrington carpet' for rotations 1597-1616 is shown in a graph. Coronal sources of high speed streams appear in the form of solid black areas. The contours of the stream sources are laid on 'evolutionary charts' of solar active region histories for the Southern and Northern Hemispheres. Questions regarding the interplay of active regions and solar wind are investigated, giving attention to developments during the years 1973, 1974, and 1975.

  8. Superstorms of November 2003 and 2004: the role of solar wind driving in the ionosphere-thermosphere dynamics

    Science.gov (United States)

    Verkhoglyadova, O. P.; Komjathy, A.; Mannucci, A. J.; Mlynczak, M. G.; Hunt, L. A.; Paxton, L. J.

    2017-12-01

    We revisit three complex superstorms of 19-20 November 2003, 7-8 November 2004 and 9-11 November 2004 to analyze ionosphere-thermosphere (IT) effects driven by different solar wind structures. We distinguish structures associated with ICMEs and their upstream sheaths. The efficiencies of the solar wind-magnetosphere connection throughout the storms are estimated by coupling functions. The daytime IT responses to the complex driving are characterized by combining measurements of characteristic IT parameters. We focus on low- and middle-latitude TEC, global thermospheric infrared nitric oxide emission, composition ratio and locations of the auroral boundary obtained from multiple satellite platforms and ground-based measurements (GPS, TIMED/SABER, TIMED/GUVI, DMSP/SSUSI). A variety of metrics are utilized to examine IT phenomena at 1 hour time scales. It is well-known that the November storm periods featured TEC responses that did not fit a typical pattern. The role of direct driving of IT dynamics by solar wind structures and the role of IT pre-conditioning in these storms are examined to explain the complex unusual ionospheric responses. We identify IT feedback effects that can be important for long-lasting strong storms.

  9. Watershed evaluation and habitat response to recent storms : annual report for 1998; ANNUAL

    International Nuclear Information System (INIS)

    Huntington, Charles W.; Rhodes, Jonathan J.

    1999-01-01

    Large and powerful storm systems moved through the Pacific Northwest during the wet season of 1995-96, triggering widespread flooding, mass erosion, and, possibly altering salmon habitats in affected watersheds. This project study was initiated to assess whether watershed conditions are causing damage, triggered by storm events, to salmon habitat on public lands in the Snake River basin

  10. Mapping and Visualization of Storm-Surge Dynamics for Hurricane Katrina and Hurricane Rita

    Science.gov (United States)

    Gesch, Dean B.

    2009-01-01

    The damages caused by the storm surges from Hurricane Katrina and Hurricane Rita were significant and occurred over broad areas. Storm-surge maps are among the most useful geospatial datasets for hurricane recovery, impact assessments, and mitigation planning for future storms. Surveyed high-water marks were used to generate a maximum storm-surge surface for Hurricane Katrina extending from eastern Louisiana to Mobile Bay, Alabama. The interpolated surface was intersected with high-resolution lidar elevation data covering the study area to produce a highly detailed digital storm-surge inundation map. The storm-surge dataset and related data are available for display and query in a Web-based viewer application. A unique water-level dataset from a network of portable pressure sensors deployed in the days just prior to Hurricane Rita's landfall captured the hurricane's storm surge. The recorded sensor data provided water-level measurements with a very high temporal resolution at surveyed point locations. The resulting dataset was used to generate a time series of storm-surge surfaces that documents the surge dynamics in a new, spatially explicit way. The temporal information contained in the multiple storm-surge surfaces can be visualized in a number of ways to portray how the surge interacted with and was affected by land surface features. Spatially explicit storm-surge products can be useful for a variety of hurricane impact assessments, especially studies of wetland and land changes where knowledge of the extent and magnitude of storm-surge flooding is critical.

  11. In the Eye of the Storm: A Participatory Course on Coastal Storms

    Science.gov (United States)

    Curtis, Scott

    2013-01-01

    Storm disasters are amplified in the coastal environment due to population pressures and the power of the sea. The upper-division/graduate university course "Coastal Storms" was designed to equip future practitioners with the skills necessary to understand, respond to, and mitigate for these natural disasters. To accomplish this, "Coastal Storms"…

  12. The statistical analysis of the Geomagnetically Induced Current events occurred in Guangdong, China during the declining phase of solar cycle 23 (2003–2006)

    Science.gov (United States)

    Ni, Y. Y.

    2018-03-01

    We study the interplanetary causes of intense geomagnetic storms (Dst ≤ -100 nT) and the corresponding Geomagnetically Induced Current (GIC) events occurred in Ling’ao nuclear power station, Guangdong during the declining phase of solar cycle 23 (2003–2006). The result shows that sMC (a magnetic cloud with a shock), SH (sheath) and SH+MC (a sheath followed by a magnetic cloud) are the three most common interplanetary structures responsible for the storms which will cause GIC events in this period. As an interplanetary structure, CIR (corotating interaction regions) also plays an important role, however, the CIR-driven storms have a relatively minor effect to the GIC. Among the interplanetary parameters, the solar wind velocity and the southward component of the IMF (interplanetary magnetic field) are more important than solar wind density and the temperature to a geomagnetic storm and GIC.

  13. Magnetic and solar effects on ionospheric absorption at high latitude

    Directory of Open Access Journals (Sweden)

    M. Pietrella

    2002-06-01

    Full Text Available Some periods of intense solar events and of strong magnetic storms have been selected and their effects on the ionospheric D region have been investigated on the basis of ionospheric absorption data derived from riometer measurements made at the Italian Antarctic Base of Terra Nova Bay (geographic coordinates: 74.69 S, 164.12 E; geomagnetic coordinates: 77.34 S, 279.41 E. It was found that sharp increases in ionospheric absorption are mainly due to solar protons emission with an energy greater than 10 MeV. Moreover, the day to night ratios of the ionospheric absorption are greater than 2 in the case of strong events of energetic protons emitted by the Sun, while during magnetic storms, these ratios range between 1 and 2.

  14. Nippon Storm Study design

    Directory of Open Access Journals (Sweden)

    Takashi Kurita

    2012-10-01

    Full Text Available An understanding of the clinical aspects of electrical storm (E-storms in patients with implantable cardiac shock devices (ICSDs: ICDs or cardiac resynchronization therapy with defibrillator [CRT-D] may provide important information for clinical management of patients with ICSDs. The Nippon Storm Study was organized by the Japanese Heart Rhythm Society (JHRS and Japanese Society of Electrocardiology and was designed to prospectively collect a variety of data from patients with ICSDs, with a focus on the incidence of E-storms and clinical conditions for the occurrence of an E-storm. Forty main ICSD centers in Japan are participating in the present study. From 2002, the JHRS began to collect ICSD patient data using website registration (termed Japanese cardiac defibrillator therapy registration, or JCDTR. This investigation aims to collect data on and investigate the general parameters of patients with ICSDs, such as clinical backgrounds of the patients, purposes of implantation, complications during the implantation procedure, and incidence of appropriate and inappropriate therapies from the ICSD. The Nippon Storm Study was planned as a sub-study of the JCDTR with focus on E-storms. We aim to achieve registration of more than 1000 ICSD patients and complete follow-up data collection, with the assumption of a 5–10% incidence of E-storms during the 2-year follow-up.

  15. Future changes in extratropical storm tracks and baroclinicity under climate change

    International Nuclear Information System (INIS)

    Lehmann, Jascha; Coumou, Dim; Frieler, Katja; Eliseev, Alexey V; Levermann, Anders

    2014-01-01

    The weather in Eurasia, Australia, and North and South America is largely controlled by the strength and position of extratropical storm tracks. Future climate change will likely affect these storm tracks and the associated transport of energy, momentum, and water vapour. Many recent studies have analyzed how storm tracks will change under climate change, and how these changes are related to atmospheric dynamics. However, there are still discrepancies between different studies on how storm tracks will change under future climate scenarios. Here, we show that under global warming the CMIP5 ensemble of coupled climate models projects only little relative changes in vertically averaged mid-latitude mean storm track activity during the northern winter, but agree in projecting a substantial decrease during summer. Seasonal changes in the Southern Hemisphere show the opposite behaviour, with an intensification in winter and no change during summer. These distinct seasonal changes in northern summer and southern winter storm tracks lead to an amplified seasonal cycle in a future climate. Similar changes are seen in the mid-latitude mean Eady growth rate maximum, a measure that combines changes in vertical shear and static stability based on baroclinic instability theory. Regression analysis between changes in the storm tracks and changes in the maximum Eady growth rate reveal that most models agree in a positive association between the two quantities over mid-latitude regions. (letter)

  16. PC index as a proxy of the solar wind energy that entered into the magnetosphere and energy accumulated in the magnetosphere

    Science.gov (United States)

    Troshichev, Oleg; Sormakov, Dmitry

    The PC index has been approved by the International Association of Geomagnetism and Aeronomy (Merida, Mexico, 2013) as a new international index of magnetic activity. Application of the PC index as a proxy of a solar wind energy that entered into the magnetosphere determines a principal distinction of the PC index from AL and Dst indices, which are regarded as characteristics of the energy that realized in magnetosphere in form of substorms and magnetic storms. This conclusion is based on results of analysis of relationships between the polar cap magnetic activity (PC-index) and parameters of the solar wind, on the one hand, relationships between changes of PC and development of magnetospheric substorms (AL-index) and magnetic storms (Dst-index), on the other hand. In this study the relationships between the PC and Dst indices in course of more than 200 magnetic storms observed in epoch of solar maximum (1998-2004) have been examined for different classes of storms separated by their kind and intensity. Results of statistical analysis demonstrate that depression of geomagnetic field starts to develop as soon as PC index steadily excess the threshold level ~1.5 mV/m; the storm intensity (DstMIN) follows, with delay ~ 1 hour, the maximum of PC in course of the storm. Main features of magnetic storms are determined, irrespective of their class and intensity, by the accumulated-mean PC value (PCAM): storm is developed as long as PCAM increases, comes to maximal intensity when PCAM attains the maximum, and starts to decay as soon as PCAM value displays decline. The run of “anomalous” magnetic storm on January 21-22, 2005, lasting many hours (with intensity of ≈ -100 nT) under conditions of northward or close to zero BZ component, is perfectly governed by behavior of the accumulated-mean PCAM index and, therefore, this storm should be regarded as an ordinary phenomenon. The conclusion is made that the PC index provides the unique on-line information on solar wind

  17. A first generation numerical geomagnetic storm prediction scheme

    International Nuclear Information System (INIS)

    Akasofu, S.-I.; Fry, C.F.

    1986-01-01

    Because geomagnetic and auroral disturbances cause significant interference on many electrical systems, it is essential to develop a reliable geomagnetic and auroral storm prediction scheme. A first generation numerical prediction scheme has been developed. The scheme consists of two major computer codes which in turn consist of a large number of subroutine codes and of empirical relationships. First of all, when a solar flare occurs, six flare parameters are determined as the input data set for the first code which is devised to show the simulated propagation of solar wind disturbances in the heliosphere to a distance of 2 a.u. Thus, one can determine the relative location of the propagating disturbances with the Earth's position. The solar wind speed and the three interplanetary magnetic field (IMF) components are then computed as a function of time at the Earth's location or any other desired (space probe) locations. These quantities in turn become the input parameters for the second major code which computes first the power of the solar wind-magnetosphere dynamo as a function of time. The power thus obtained and the three IMF components can be used to compute or infer: the predicted geometry of the auroral oval; the cross-polar cap potential; the two geomagnetic indices AE and Dst; the total energy injection rate into the polar ionosphere; and the atmospheric temperature, etc. (author)

  18. Dst Prediction Based on Solar Wind Parameters

    Directory of Open Access Journals (Sweden)

    Yoon-Kyung Park

    2009-12-01

    Full Text Available We reevaluate the Burton equation (Burton et al. 1975 of predicting Dst index using high quality hourly solar wind data supplied by the ACE satellite for the period from 1998 to 2006. Sixty magnetic storms with monotonously decreasing main phase are selected. In order to determine the injection term (Q and the decay time (tau of the equation, we examine the relationships between Dst* and VB_s, Delta Dst* and VB_s, and Delta Dst* and Dst* during the magnetic storms. For this analysis, we take into account one hour of the propagation time from the ACE satellite to the magnetopause, and a half hour of the response time of the magnetosphere/ring current to the solar wind forcing. The injection term is found to be Q({nT}/h=-3.56VB_s for VB_s>0.5mV/m and Q({nT}/h=0 for VB_s leq0.5mV/m. The tau (hour is estimated as 0.060 Dst* + 16.65 for Dst*>-175nT and 6.15 hours for Dst* leq -175nT. Based on these empirical relationships, we predict the 60 magnetic storms and find that the correlation coefficient between the observed and predicted Dst* is 0.88. To evaluate the performance of our prediction scheme, the 60 magnetic storms are predicted again using the models by Burton et al. (1975 and O'Brien & McPherron (2000a. The correlation coefficients thus obtained are 0.85, the same value for both of the two models. In this respect, our model is slightly improved over the other two models as far as the correlation coefficients is concerned. Particularly our model does a better job than the other two models in predicting intense magnetic storms (Dst* lesssim -200nT.

  19. Handbook of the Solar-Terrestrial Environment

    CERN Document Server

    Kamide, Y

    2007-01-01

    The Handbook of the Solar-Terrestrial Environment is a unique compendium. Recognized international leaders in their field contribute chapters on basic topics of solar physics, space plasmas and the Earth's magnetosphere, and on applied topics like the aurora, magnetospheric storms, space weather, space climatology and planetary science. This book will be of highest value as a reference for researchers working in the area of planetary and space science. However, it is also written in a style accessible to graduate students majoring in those fields.

  20. Ionospheric Storm Effects and Equatorial Plasma Irregularities During the 17-18 March 2015 Event

    Science.gov (United States)

    Zhou, Yun-Liang; Luhr, Hermann; Xiong, Chao; Pfaff, Robert F.

    2016-01-01

    The intense magnetic storm on 17-18 March 2015 caused large disturbances of the ionosphere. Based on the plasma density (Ni) observations performed by the Swarm fleet of satellites, the Gravity Recovery and Climate Experiment mission, and the Communications/Navigation Outage Forecasting System satellite, we characterize the storm-related perturbations at low latitudes. All these satellites sampled the ionosphere in morning and evening time sectors where large modifications occurred. Modifications of plasma density are closely related to changes of the solar wind merging electric field (E (sub m)). We consider two mechanisms, prompt penetration electric field (PPEF) and disturbance dynamo electric field (DDEF), as the main cause for the Ni redistribution, but effects of meridional wind are also taken into account. At the start of the storm main phase, the PPEF is enhancing plasma density on the dayside and reducing it on the nightside. Later, DDEF takes over and causes the opposite reaction. Unexpectedly, there appears during the recovery phase a strong density enhancement in the morning/pre-noon sector and a severe Ni reduction in the afternoon/evening sector, and we suggest a combined effect of vertical plasma drift, and meridional wind is responsible for these ionospheric storm effects. Different from earlier studies about this storm, we also investigate the influence of storm dynamics on the initiation of equatorial plasma irregularities (EPIs). Shortly after the start of the storm main phase, EPIs appear in the post-sunset sector. As a response to a short-lived decline of E (sub m), EPI activity appears in the early morning sector. Following the second start of the main phase, EPIs are generated for a few hours in the late evening sector. However, for the rest of the storm main phase, no more EPIs are initiated for more than 12 hours. Only after the onset of recovery phase does EPI activity start again in the post-midnight sector, lasting more than 7 hours

  1. Biological effects of geomagnetic storms

    International Nuclear Information System (INIS)

    Chibisov, S.M.; Breus, T.K.; Levitin, A.E.; Drogova, G.M.; AN SSSR, Moscow; AN SSSR, Moscow

    1995-01-01

    Six physiological parameters of cardio-vascular system of rabbits and ultrastructure of cardiomyocytes were investigated during two planetary geomagnetic storms. At the initial and main phase of the storm the normal circadian structure in each cardiovascular parameter was lost. The disynchronozis was growing together with the storm and abrupt drop of cardia activity was observed during the main phase of storm. The main phase of storm followed by the destruction and degradation of cardiomyocytes. Parameters of cardia activity became substantially synchronized and characterized by circadian rhythm structure while the amplitude of deviations was still significant at the recovery stage of geomagnetic storm. 3 refs.; 7 figs

  2. SYMPATHETIC SOLAR FILAMENT ERUPTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Rui; Liu, Ying D.; Zimovets, Ivan; Hu, Huidong; Yang, Zhongwei [State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190 (China); Dai, Xinghua, E-mail: liuxying@spaceweather.ac.cn [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2016-08-10

    The 2015 March 15 coronal mass ejection as one of the two that together drove the largest geomagnetic storm of solar cycle 24 so far was associated with sympathetic filament eruptions. We investigate the relations between the different filaments involved in the eruption. A surge-like small-scale filament motion is confirmed as the trigger that initiated the erupting filament with multi-wavelength observations and using a forced magnetic field extrapolation method. When the erupting filament moved to an open magnetic field region, it experienced an obvious acceleration process and was accompanied by a C-class flare and the rise of another larger filament that eventually failed to erupt. We measure the decay index of the background magnetic field, which presents a critical height of 118 Mm. Combining with a potential field source surface extrapolation method, we analyze the distributions of the large-scale magnetic field, which indicates that the open magnetic field region may provide a favorable condition for F2 rapid acceleration and have some relation with the largest solar storm. The comparison between the successful and failed filament eruptions suggests that the confining magnetic field plays an important role in the preconditions for an eruption.

  3. Typhoon Haiyan-Induced Storm Surge Simulation in Metro Manila Using High-Resolution LiDAR Topographic Data

    Science.gov (United States)

    Santiago, J. T.

    2015-12-01

    Storm surge is the abnormal rise in sea water over and above astronomical tides due to a forthcoming storm. Developing an early warning system for storm surges is vital due to the high level of hazard they might cause. On 08 November 2013, Typhoon Haiyan generated storm surges that killed over 6,000 people in the central part of the Philippines. The Nationwide Operational Assessment of Hazards under the Department of Science and Technology was tasked to create storm surge hazard maps for the country's coastal areas. The research project aims to generate storm surge hazard maps that can be used for disaster mitigation and planning. As part of the research, the team explored a scenario wherein a tropical cyclone hits the Metro Manila with strength as strong as Typhoon Haiyan. The area was chosen primarily for its political, economic and cultural significance as the country's capital. Using Japan Meteorological Agency Storm Surge model, FLO2D flooding software, LiDAR topographic data, and GIS technology, the effects of a Haiyan-induced tropical cyclone passing through Metro Manila was examined. The population affected, number of affected critical facilities, and potential evacuation sites were identified. The outputs of this study can be used by the authorities as basis for policies that involve disaster risk reduction and management.

  4. High-latitude topside ionospheric vertical electron density profile changes in response to large magnetic storms

    Czech Academy of Sciences Publication Activity Database

    Benson, R. F.; Fainberg, J.; Osherovich, V. A.; Truhlík, Vladimír; Wang, Y.; Bilitza, D.; Fung, S. F.

    2016-01-01

    Roč. 51, č. 5 (2016), s. 524-537 ISSN 0048-6604 R&D Projects: GA ČR(CZ) GC15-07281J Institutional support: RVO:68378289 Keywords : topside ionosphere * magnetic storm * solar wind Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.581, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/2015RS005882/full

  5. Total electron content responses to HILDCAAs and geomagnetic storms over South America

    Directory of Open Access Journals (Sweden)

    P. M. de Siqueira Negreti

    2017-12-01

    Full Text Available Total electron content (TEC is extensively used to monitor the ionospheric behavior under geomagnetically quiet and disturbed conditions. This subject is of greatest importance for space weather applications. Under disturbed conditions the two main sources of electric fields, which are responsible for changes in the plasma drifts and for current perturbations, are the short-lived prompt penetration electric fields (PPEFs and the longer-lasting ionospheric disturbance dynamo (DD electric fields. Both mechanisms modulate the TEC around the globe and the equatorial ionization anomaly (EIA at low latitudes. In this work we computed vertical absolute TEC over the low latitude of South America. The analysis was performed considering HILDCAA (high-intensity, long-duration, continuous auroral electrojet (AE activity events and geomagnetic storms. The characteristics of storm-time TEC and HILDCAA-associated TEC will be presented and discussed. For both case studies presented in this work (March and August 2013 the HILDCAA event follows a geomagnetic storm, and then a global scenario of geomagnetic disturbances will be discussed. Solar wind parameters, geomagnetic indices, O ∕ N2 ratios retrieved by GUVI instrument onboard the TIMED satellite and TEC observations will be analyzed and discussed. Data from the RBMC/IBGE (Brazil and IGS GNSS networks were used to calculate TEC over South America. We show that a HILDCAA event may generate larger TEC differences compared to the TEC observed during the main phase of the precedent geomagnetic storm; thus, a HILDCAA event may be more effective for ionospheric response in comparison to moderate geomagnetic storms, considering the seasonal conditions. During the August HILDCAA event, TEC enhancements from  ∼  25 to 80 % (compared to quiet time were observed. These enhancements are much higher than the quiet-time variability observed in the ionosphere. We show that ionosphere is quite sensitive to

  6. Solar--geophysical data number 406, June 1978, Part I. (prompt reports). Data for May 1978, April 1978

    International Nuclear Information System (INIS)

    Coffey, H.E.

    1978-06-01

    This prompt report provides data for May 1978 on: alert period, daily solar indices, solar flares, solar radio waves, solar x-ray radiation, coronal holes, inferred IP Magnetic field polarities, mean solar magnetic field, solar wind measurements, geomagnetic substorms, magnetograms of geomagnetic storm 30 April - 4 May, and energetic solar particles. It also provides data for April 1978 on: daily solar activity center, sudden ionospheric disturbances, solar x-ray radiation, solar radio waves, cosmic rays, geomagnetic indices, and radio propagation

  7. Solar cosmic rays in the system of solar terrestrial relations

    Science.gov (United States)

    Miroshnichenko, Leonty I.

    2008-02-01

    In this brief review, we discuss a number of geophysical effects of solar energetic particles (SEPs) or solar cosmic rays (SCR). We concentrate mainly on the observational evidence and proposed mechanisms of some expected effects and/or poor-studied phenomena discovered within the last three decades, in particular, depletion of the ozone layer, perturbations in the global electric current, effects on the winter storm vorticity, change of the atmospheric transparency and production of nitrates. Some "archaeological" data on SCR fluxes in the past and upper limit of total energy induced by SEPs are also discussed. Due attention is paid to the periodicities in the solar particle fluxes. Actually, many solar, heliospheric and terrestrial parameters changing generally in phase with the solar activity are subjected to a temporary depression close to the solar maximum ("Gnevyshev Gap"). A similar gap has been found recently in the yearly numbers of the >10 MeV proton events. All the above-mentioned findings are evidently of great importance in the studies of general proton emissivity of the Sun and long-term trends in the behaviour of solar magnetic fields. In addition, these data can be very helpful for elaborating the methods for prediction of the radiation conditions in space and for estimation of the SEPs' contribution to solar effects on the geosphere, their relative role in the formation of terrestrial weather and climate and in the problem of solar-terrestrial relations (STR) on the whole.

  8. The Pioneer 9 electric field experiment. III - Radial gradients and storm observations.

    Science.gov (United States)

    Scarf, F. L.; Green, I. M.; Burgess, J. S.

    1973-01-01

    We present a detailed analysis of the Pioneer 9 VLF electric field observations for 20 selected storm periods covering a heliocentric range extending from 0.754 AU to 0.99 AU. Although data from only two low frequency channels are available, the results of the present study tend to confirm the preliminary speculation by Scarf and Siscoe (1971) that the turbulent E-field spectrum in the disturbed solar wind has a significant radial gradient.

  9. Empirical Storm-Time Correction to the International Reference Ionosphere Model E-Region Electron and Ion Density Parameterizations Using Observations from TIMED/SABER

    Science.gov (United States)

    Mertens, Christoper J.; Winick, Jeremy R.; Russell, James M., III; Mlynczak, Martin G.; Evans, David S.; Bilitza, Dieter; Xu, Xiaojing

    2007-01-01

    The response of the ionospheric E-region to solar-geomagnetic storms can be characterized using observations of infrared 4.3 micrometers emission. In particular, we utilize nighttime TIMED/SABER measurements of broadband 4.3 micrometers limb emission and derive a new data product, the NO+(v) volume emission rate, which is our primary observation-based quantity for developing an empirical storm-time correction the IRI E-region electron density. In this paper we describe our E-region proxy and outline our strategy for developing the empirical storm model. In our initial studies, we analyzed a six day storm period during the Halloween 2003 event. The results of this analysis are promising and suggest that the ap-index is a viable candidate to use as a magnetic driver for our model.

  10. Large enhancements in low latitude total electron content during 15 May 2005 geomagnetic storm in Indian zone

    Directory of Open Access Journals (Sweden)

    N. Dashora

    2009-05-01

    Full Text Available Results pertaining to the response of the equatorial and low latitude ionosphere to a major geomagnetic storm that occurred on 15 May 2005 are presented. These results are also the first from the Indian zone in terms of (i GPS derived total electron content (TEC variations following the storm (ii Local low latitude electrodynamics response to penetration of high latitude convection electric field (iii effect of storm induced traveling atmospheric disturbances (TAD's on GPS-TEC in equatorial ionization anomaly (EIA zone. Data set comprising of ionospheric TEC obtained from GPS measurements, ionograms from an EIA zone station, New Delhi (Geog. Lat. 28.42° N, Geog. Long. 77.21° E, ground based magnetometers in equatorial and low latitude stations and solar wind data obtained from Advanced Composition Explorer (ACE has been used in the present study. GPS receivers located at Udaipur (Geog. Lat. 24.73° N, Geog. Long. 73.73° E and Hyderabad (Geog. Lat. 17.33° N, Geog. Long. 78.47° E have been used for wider spatial coverage in the Indian zone. Storm induced features in vertical TEC (VTEC have been obtained comparing them with the mean VTEC of quiet days. Variations in solar wind parameters, as obtained from ACE and in the SYM-H index, indicate that the storm commenced on 15 May 2005 at 02:39 UT. The main phase of the storm commenced at 06:00 UT on 15 May with a sudden southward turning of the Z-component of interplanetary magnetic field (IMF-Bz and subsequent decrease in SYM-H index. The dawn-to-dusk convection electric field of high latitude origin penetrated to low and equatorial latitudes simultaneously as corroborated by the magnetometer data from the Indian zone. Subsequent northward turning of the IMF-Bz, and the penetration of the dusk-to-dawn electric field over the dip equator is also discernible. Response of the low latitude ionosphere to this storm may be characterized in terms of (i enhanced background level of VTEC as compared to

  11. Large enhancements in low latitude total electron content during 15 May 2005 geomagnetic storm in Indian zone

    Directory of Open Access Journals (Sweden)

    N. Dashora

    2009-05-01

    Full Text Available Results pertaining to the response of the equatorial and low latitude ionosphere to a major geomagnetic storm that occurred on 15 May 2005 are presented. These results are also the first from the Indian zone in terms of (i GPS derived total electron content (TEC variations following the storm (ii Local low latitude electrodynamics response to penetration of high latitude convection electric field (iii effect of storm induced traveling atmospheric disturbances (TAD's on GPS-TEC in equatorial ionization anomaly (EIA zone.

    Data set comprising of ionospheric TEC obtained from GPS measurements, ionograms from an EIA zone station, New Delhi (Geog. Lat. 28.42° N, Geog. Long. 77.21° E, ground based magnetometers in equatorial and low latitude stations and solar wind data obtained from Advanced Composition Explorer (ACE has been used in the present study. GPS receivers located at Udaipur (Geog. Lat. 24.73° N, Geog. Long. 73.73° E and Hyderabad (Geog. Lat. 17.33° N, Geog. Long. 78.47° E have been used for wider spatial coverage in the Indian zone. Storm induced features in vertical TEC (VTEC have been obtained comparing them with the mean VTEC of quiet days. Variations in solar wind parameters, as obtained from ACE and in the SYM-H index, indicate that the storm commenced on 15 May 2005 at 02:39 UT. The main phase of the storm commenced at 06:00 UT on 15 May with a sudden southward turning of the Z-component of interplanetary magnetic field (IMF-Bz and subsequent decrease in SYM-H index. The dawn-to-dusk convection electric field of high latitude origin penetrated to low and equatorial latitudes simultaneously as corroborated by the magnetometer data from the Indian zone. Subsequent northward turning of the IMF-Bz, and the penetration of the dusk-to-dawn electric field over the dip equator is also discernible. Response of the low latitude ionosphere to this storm may be characterized in terms of (i

  12. Estimating the geoeffectiveness of halo CMEs from associated solar and IP parameters using neural networks

    Directory of Open Access Journals (Sweden)

    J. Uwamahoro

    2012-06-01

    Full Text Available Estimating the geoeffectiveness of solar events is of significant importance for space weather modelling and prediction. This paper describes the development of a neural network-based model for estimating the probability occurrence of geomagnetic storms following halo coronal mass ejection (CME and related interplanetary (IP events. This model incorporates both solar and IP variable inputs that characterize geoeffective halo CMEs. Solar inputs include numeric values of the halo CME angular width (AW, the CME speed (Vcme, and the comprehensive flare index (cfi, which represents the flaring activity associated with halo CMEs. IP parameters used as inputs are the numeric peak values of the solar wind speed (Vsw and the southward Z-component of the interplanetary magnetic field (IMF or Bs. IP inputs were considered within a 5-day time window after a halo CME eruption. The neural network (NN model training and testing data sets were constructed based on 1202 halo CMEs (both full and partial halo and their properties observed between 1997 and 2006. The performance of the developed NN model was tested using a validation data set (not part of the training data set covering the years 2000 and 2005. Under the condition of halo CME occurrence, this model could capture 100% of the subsequent intense geomagnetic storms (Dst ≤ −100 nT. For moderate storms (−100 < Dst ≤ −50, the model is successful up to 75%. This model's estimate of the storm occurrence rate from halo CMEs is estimated at a probability of 86%.

  13. IPS observations of transient interplanetary phenomena associated with solar filament activity in late august

    International Nuclear Information System (INIS)

    Watanabe, Takashi; Marubashi, Katsuhide.

    1985-01-01

    Large-scale structures of the solar wind plasma during the severe geomagnetic storm of August 27-29, 1978 are studied on the basis of IPS and spacecraft observations. Three-dimensional configuration of an interplanetary disturbance which caused the SSC of August 27, 1978 was an oblate sphere having an axial ratio of 1.7. Approximate excess mass and kinetic energy contained within the high-speed portion of the disturbance (--500 km s -1 ) were 10 16 g and 3 x 10 31 erg, respectively. An interplanetary disturbance was also observed on August 28, 1978 during the main phase of the geomagnetic storm. It is suggested that the solar-filament activity which took place near the solar disk center in August 23-25, 1978 caused these interplanetary disturbances. (author)

  14. Occurrence of Equatorial Plasma Bubbles during Intense Magnetic Storms

    Directory of Open Access Journals (Sweden)

    Chao-Song Huang

    2011-01-01

    Full Text Available An important issue in low-latitude ionospheric space weather is how magnetic storms affect the generation of equatorial plasma bubbles. In this study, we present the measurements of the ion density and velocity in the evening equatorial ionosphere by the Defense Meteorological Satellite Program (DMSP satellites during 22 intense magnetic storms. The DMSP measurements show that deep ion density depletions (plasma bubbles are generated after the interplanetary magnetic field (IMF turns southward. The time delay between the IMF southward turning and the first DMSP detection of plasma depletions decreases with the minimum value of the IMF Bz, the maximum value of the interplanetary electric field (IEF Ey, and the magnitude of the Dst index. The results of this study provide strong evidence that penetration electric field associated with southward IMF during the main phase of magnetic storms increases the generation of equatorial plasma bubbles in the evening sector.

  15. Uplift of Ionospheric Oxygen Ions During Extreme Magnetic Storms

    Science.gov (United States)

    Tsurutani, Bruce T.; Mannucci, Anthony J.; Verkhoglyadova, Olga P.; Huba, Joseph; Lakhina, Gurbax S.

    2013-01-01

    Research reported earlier in literature was conducted relating to estimation of the ionospheric electrical field, which may have occurred during the September 1859 Carrington geomagnetic storm event, with regard to modern-day consequences. In this research, the NRL SAMI2 ionospheric code has been modified and applied the estimated electric field to the dayside ionosphere. The modeling was done at 15-minute time increments to track the general ionospheric changes. Although it has been known that magnetospheric electric fields get down into the ionosphere, it has been only in the last ten years that scientists have discovered that intense magnetic storm electric fields do also. On the dayside, these dawn-to-dusk directed electric fields lift the plasma (electrons and ions) up to higher altitudes and latitudes. As plasma is removed from lower altitudes, solar UV creates new plasma, so the total plasma in the ionosphere is increased several-fold. Thus, this complex process creates super-dense plasmas at high altitudes (from 700 to 1,000 km and higher).

  16. Ring current and auroral electrojets in connection with interplanetary medium parameters during magnetic storm

    Directory of Open Access Journals (Sweden)

    Y. I. Feldstein

    Full Text Available The relationship between the auroral electrojet indices (AE and the ring current magnetic field (DR was investigated by observations obtained during the magnetic storm on 1-3 April 1973. During the storm main phase the DR development is accompanied by a shift of the auroral electrojets toward the equator. As a result, the standard AE indices calculated on the basis of data from auroral observatories was substantially lower than the real values (AE'. To determine AE' during the course of a storm main phase data from subauroral magnetic observatories should be used. It is shown that the intensity of the indices (AE' which take into account the shift of the electrojets is increased substantially relative to the standard indices during the storm main phase. AE' values are closely correlated with geoeffective solar wind parameters. A high correlation was obtained between AE' and the energy flux into the ring current during the storm main phase. Analysis of magnetic field variations during intervals with intense southward IMF components demonstrates a decrease of the saturation effect of auroral electrojet currents if subauroral stations magnetic field variations are taken into account. This applies both to case studies and statistical data. The dynamics of the electrojets in connection with the development of the ring current and of magnetospheric substorms can be described by the presence (absence of saturation for minimum (maximum AE index values during a 1-h interval. The ring current magnetic field asymmetry (ASY was calculated as the difference between the maximum and minimum field values along a parallel of latitude at low latitudes. The ASY value is closely correlated with geoeffective solar wind parameters and simultaneously is a more sensitive indicator of IMF Bz variations than the symmetric ring current.

  17. Radiation From Solar Activity | Radiation Protection | US EPA

    Science.gov (United States)

    2017-08-07

    Solar flares, coronal mass ejections (CMEs) and geomagnetic storms from the sun can send extreme bursts of ionizing radiation and magnetic energy toward Earth. Some of this energy is in the form ionizing radiation and some of the energy is magnetic energy.

  18. Analysis of storm-tide impacts from Hurricane Sandy in New York

    Science.gov (United States)

    Schubert, Christopher E.; Busciolano, Ronald J.; Hearn, Paul P.; Rahav, Ami N.; Behrens, Riley; Finkelstein, Jason S.; Monti, Jack; Simonson, Amy E.

    2015-07-21

    The hybrid cyclone-nor’easter known as Hurricane Sandy affected the mid-Atlantic and northeastern United States during October 28-30, 2012, causing extensive coastal flooding. Prior to storm landfall, the U.S. Geological Survey (USGS) deployed a temporary monitoring network from Virginia to Maine to record the storm tide and coastal flooding generated by Hurricane Sandy. This sensor network augmented USGS and National Oceanic and Atmospheric Administration (NOAA) networks of permanent monitoring sites that also documented storm surge. Continuous data from these networks were supplemented by an extensive post-storm high-water-mark (HWM) flagging and surveying campaign. The sensor deployment and HWM campaign were conducted under a directed mission assignment by the Federal Emergency Management Agency (FEMA). The need for hydrologic interpretation of monitoring data to assist in flood-damage analysis and future flood mitigation prompted the current analysis of Hurricane Sandy by the USGS under this FEMA mission assignment.

  19. Equatorial All Sky Imager Images from the Seychelles during the March 17th, 2015 geomagnetic storm.

    Science.gov (United States)

    Curtis, B.

    2015-12-01

    An all sky imager was installed in the Seychelles earlier this year. The Seychelles islands are located northeast of Madagascar and east of Somalia in the equatorial Indian Ocean. The all sky imager is located on the island of Mahe (4.6667°S, 55.4667°E geographic), (10.55°S, 127.07°E geomagnetic), with filters of 557.7, 620.0, 630.0, 765.0 and 777.4 nm. Images with a 90 second exposure from Seychelles in 777.4nm and 630.0nm from the night before and night of the March 17th geomagnetic storm are discussed in comparison to solar wind measurements at ACE and the disturbance storm time (Dst) index. These images show line-of-sight intensities of photons received dependent on each filters wavelength. A time series of these images sometimes will show the movement of relatively dark areas, or depletions, in each emission. The depletion regions are known to cause scintillation in GPS signals. The direction and speed of movement of these depletions are related to changes observed in the solar wind.

  20. Lightning Evolution In Two North Central Florida Summer Multicell Storms and Three Winter/Spring Frontal Storms

    Science.gov (United States)

    Caicedo, J. A.; Uman, M. A.; Pilkey, J. T.

    2018-01-01

    We present the first lightning evolution studies, via the Lightning Mapping Array (LMA) and radar, performed in North Central Florida. Parts of three winter/spring frontal storms (cold season) and two complete summer (warm season) multicell storms are studied. Storm parameters measured are as follows: total number of flashes, flash-type classification, first flashes, flash initiation altitude, flash initiation power, flash rate (flashes per minute), charge structure, altitude and temperature ranges of the inferred charge regions, atmospheric isotherm altitude, radar base reflectivity (dBZ), and radar echo tops (EET). Several differences were found between summer multicell and winter/spring frontal storms in North Central Florida: (1) in winter/spring storms, the range of altitudes that all charge regions occupy is up to 1 km lower in altitude than in summer storms, as are the 0°C, -10°C, and -20°C isotherms; (2) lightning activity in summer storms is highly correlated with changes in radar signatures, in particular, echo tops; and (3) the LMA average initiation power of all flash types in winter/frontal storms is about an order of magnitude larger than that for summer storms. In relation to storms in other geographical locations, North Central Florida seasonal storms were found to have similarities in most parameters studied with a few differences, examples in Florida being (1) colder initiation altitudes for intracloud flashes, (2) charge regions occupying larger ranges of atmospheric temperatures, and (3) winter/spring frontal storms not having much lightning activity in the stratiform region.

  1. Development of a Severe Sand-dust Storm Model and its Application to Northwest China

    International Nuclear Information System (INIS)

    Zhang Xiaoling; Cheng, Linsheng; Chung, Yong-Seung

    2003-01-01

    A very strong sand-dust storm occurred on 5 May, 1993 in Northwest China. In order to give a detailed description of the evolution of a mesoscale system along with the heavy sand-dust storm, a complex model including improved physical processes and a radiation parameterization scheme was developed based on a simulation model. The improved model introduced a sand-dust transport equation as well as a lifting transport model, sand-dust aerosols and radiation parameterization scheme.Using this model, the super sand-dust storm case on 5 May was simulated. Results indicated that the coupled mesoscale model successfully simulated the mesoscale vortex, its strong upward movement and the warm core structure of PBL. The generation and development of these structures were consistent with that of the sand-dust storm and dry squall-line (which was different with normal squall-line). Simulated sand-dust concentration and its radiative effect corresponded with observation data. The radiative effect of sand-dust aerosols caused the air to heat on the top of aerosol layer with a heating rate amounting to 2 K hr -1 . As a result, solar radiation flux that reached the surface, net radiation flux and surface temperature all suddenly went down. The temperature gradient across the cold front became obviously larger. Therefore, enhancing the development of the mesoscale system. The simulation generally reflected features during the squall-line passage of this strong sand-dust storm

  2. Birthdates of patients affected by mental illness and solar activity: A study from Italy

    Science.gov (United States)

    Ventriglio, Antonio; Borelli, Albacenzina; Bellomo, Antonello; Lepore, Alberto

    2011-04-01

    PurposeThis epidemiologic study tested an hypothesized association between the year of birth of persons with major mental illnesses and solar activity over the past century. MethodsWe collected data on diagnoses and birthdates of psychiatric patients born between 1926 and 1975 (N = 1954) in south Italy for comparison to yearly solar activity as registered by the International Observatories. ResultsWe found a strong inverse correlation between high solar activity (HSA) and incidence of schizophrenia and bipolar disorder in a 20-year period whereas the incidence of non-affective/non-psychotic disorders was moderately associated with HSA in the same period. ConclusionsInterpretation of the observed correlations between HSA during years of birth and the incidence of mental illnesses remains unclear, but the findings encourage further study.

  3. The value of wetlands in protecting southeast louisiana from hurricane storm surges.

    Science.gov (United States)

    Barbier, Edward B; Georgiou, Ioannis Y; Enchelmeyer, Brian; Reed, Denise J

    2013-01-01

    The Indian Ocean tsunami in 2004 and Hurricanes Katrina and Rita in 2005 have spurred global interest in the role of coastal wetlands and vegetation in reducing storm surge and flood damages. Evidence that coastal wetlands reduce storm surge and attenuate waves is often cited in support of restoring Gulf Coast wetlands to protect coastal communities and property from hurricane damage. Yet interdisciplinary studies combining hydrodynamic and economic analysis to explore this relationship for temperate marshes in the Gulf are lacking. By combining hydrodynamic analysis of simulated hurricane storm surges and economic valuation of expected property damages, we show that the presence of coastal marshes and their vegetation has a demonstrable effect on reducing storm surge levels, thus generating significant values in terms of protecting property in southeast Louisiana. Simulations for four storms along a sea to land transect show that surge levels decline with wetland continuity and vegetation roughness. Regressions confirm that wetland continuity and vegetation along the transect are effective in reducing storm surge levels. A 0.1 increase in wetland continuity per meter reduces property damages for the average affected area analyzed in southeast Louisiana, which includes New Orleans, by $99-$133, and a 0.001 increase in vegetation roughness decreases damages by $24-$43. These reduced damages are equivalent to saving 3 to 5 and 1 to 2 properties per storm for the average area, respectively.

  4. The upper atmosphere and solar-terrestrial relations - An introduction to the aerospace environment

    International Nuclear Information System (INIS)

    Hargreaves, J.K.

    1979-01-01

    A theoretical and observational overview of earth's aerospace environment is presented in this book. Emphasis is placed on the principles and observed phenomena of the neutral upper atmosphere, particularly in relation to solar activity. Topics include the structure of the ionosphere and magnetosphere, waves in the magnetosphere, solar flares and solar protons, and storms and other disturbance phenomena, while applications to communications, navigation and space technology are also discussed

  5. Solar Storm GIC Forecasting: Solar Shield Extension Development of the End-User Forecasting System Requirements

    Science.gov (United States)

    Pulkkinen, A.; Mahmood, S.; Ngwira, C.; Balch, C.; Lordan, R.; Fugate, D.; Jacobs, W.; Honkonen, I.

    2015-01-01

    A NASA Goddard Space Flight Center Heliophysics Science Division-led team that includes NOAA Space Weather Prediction Center, the Catholic University of America, Electric Power Research Institute (EPRI), and Electric Research and Management, Inc., recently partnered with the Department of Homeland Security (DHS) Science and Technology Directorate (S&T) to better understand the impact of Geomagnetically Induced Currents (GIC) on the electric power industry. This effort builds on a previous NASA-sponsored Applied Sciences Program for predicting GIC, known as Solar Shield. The focus of the new DHS S&T funded effort is to revise and extend the existing Solar Shield system to enhance its forecasting capability and provide tailored, timely, actionable information for electric utility decision makers. To enhance the forecasting capabilities of the new Solar Shield, a key undertaking is to extend the prediction system coverage across Contiguous United States (CONUS), as the previous version was only applicable to high latitudes. The team also leverages the latest enhancements in space weather modeling capacity residing at Community Coordinated Modeling Center to increase the Technological Readiness Level, or Applications Readiness Level of the system http://www.nasa.gov/sites/default/files/files/ExpandedARLDefinitions4813.pdf.

  6. [Diagnosis and treatment of thyroid storm].

    Science.gov (United States)

    Akamizu, Takashi

    2012-11-01

    Thyrotoxic storm is a life-threatening condition requiring emergency treatment. Neither its epidemiological data nor diagnostic criteria have been fully established. We clarified the clinical and epidemiological characteristics of thyroid storm using nationwide surveys and then formulate diagnostic criteria for thyroid storm. To perform the nationwide survey on thyroid storm, we first developed tentative diagnostic criteria for thyroid storm, mainly based upon the literature (the first edition). We analyzed the relationship of the major features of thyroid storm to mortality and to certain other features. Finally, based upon the findings of these surveys, we revised the diagnostic criteria. Thyrotoxic storm is still a life-threatening disorder with over 10% mortality in Japan.

  7. Ionospheric response over Europe during the solar eclipse of March 20, 2015

    Directory of Open Access Journals (Sweden)

    Hoque Mohammed Mainul

    2016-01-01

    Full Text Available The solar eclipse on March 20, 2015 was a fascinating event for people in Northern Europe. From a scientific point of view, the solar eclipse can be considered as an in situ experiment on the Earth’s upper atmosphere with a well-defined switching off and on of solar irradiation. Due to the strong changes in solar radiation during the eclipse, dynamic processes were initiated in the atmosphere and ionosphere causing a measurable impact, for example, on temperature and ionization. We analyzed the behavior of total ionospheric ionization over Europe by reconstructing total electron content (TEC maps and differential TEC maps. Investigating the large depletion zone around the shadow spot, we found a TEC reduction of up to 6 TEC units, i.e., the total plasma depletion reached up to about 50%. However, the March 20, 2015 eclipse occurred during the recovery phase of a strong geomagnetic storm and the ionosphere was still perturbed and depleted. Therefore, the unusual high depletion is due to the negative bias of up to 20% already observed over Northern Europe before the eclipse occurred. After removing the negative storm effect, the eclipse-induced depletion amounts to about 30%, which is in agreement with previous observations. During the solar eclipse, ionospheric plasma redistribution processes significantly affected the shape of the electron density profile, which is seen in the equivalent slab thickness derived by combining vertical incidence sounding (VS and TEC measurements. We found enhanced slab thickness values revealing, on the one hand, an increased width of the ionosphere around the maximum phase and, on the other, evidence for delayed depletion of the topside ionosphere. Additionally, we investigated very low frequency (VLF signal strength measurements and found immediate amplitude changes due to ionization loss at the lower ionosphere during the eclipse time. We found that the magnitude of TEC depletion is linearly dependent on the

  8. Influence of storm characteristics on soil erosion and storm runoff

    Science.gov (United States)

    Johnny M. III Grace

    2008-01-01

    Unpaved forest roads can be major sources of sediment from forested watersheds. Storm runoff from forest roads are a concern due to their potential delivery of sediments and nutrients to stream systems resulting in degraded water quality. The volume and sediment concentrations of stormwater runoff emanating from forest roads can be greatly influenced by storm...

  9. Thermospheric storms and related ionospheric effects

    International Nuclear Information System (INIS)

    Chandra, S.; Spencer, N.W.

    1976-01-01

    A comparative study of thermospheric storms for the equinox and winter conditions is presented based on the neutral composition measurements from the Aeros-A Nate (Neutral Atmosphere Temperature Experiment) experiment. The main features of the two storms as inferred from the changes in N 2 , Ar, He, and O are described, and their implications to current theories of thermospheric storms are discussed. On the basis of the study of the F region critical frequency measured from a chain of ground-based ionospheric stations during the two storm periods, the general characteristics of the ionospheric storms and the traveling ionospheric disturbances are described. It is suggested that the positive and negative phases of ionospheric storms are the various manifestations of thermospheric storms

  10. Impacts of sand and dust storms on agriculture and potential agricultural applications of a SDSWS

    International Nuclear Information System (INIS)

    Stefanski, R; Sivakumar, M V K

    2009-01-01

    This paper will give an overview of the various impacts of sand and dust storms on agriculture and then address the potential applications of a Sand and Dust Storm Warning System (SDSWS) for agricultural users. Sand and dust storms have many negative impacts on the agricultural sector including: reducing crop yields by burial of seedlings under sand deposits, the loss of plant tissue and reduced photosynthetic activity as a result of sandblasting, delaying plant development, increasing end-of-season drought risk, causing injury and reduced productivity of livestock, increasing soil erosion and accelerating the process of land degradation and desertification, filling up irrigation canals with sediments, covering transportation routes, affecting water quality of rivers and streams, and affecting air quality. One positive impact is the fertilization of soil minerals to terrestrial ecosystems. There are several potential agricultural applications of a SDSWS. The first is to alert agricultural communities farmers to take preventive action in the near-term such as harvesting maturing crops (vegetables, grain), sheltering livestock, and strengthening infrastructure (houses, roads, grain storage) for the storm. Also, the products of a SDSWS could be used in for monitoring potential locust movement and post-storm crop damage assessments. An archive of SDSWS products (movement, amount of sand and dust) could be used in researching plant and animal pathogen movement and the relationship of sand and dust storms to disease outbreaks and in developing improved soil erosion and land degradation models.

  11. Detailed Analysis of Solar Data Related to Historical Extreme Geomagnetic Storms: 1868 – 2010

    DEFF Research Database (Denmark)

    Lefèvre, Laure; Vennerstrøm, Susanne; Dumbović, Mateja

    2016-01-01

    An analysis of historical Sun–Earth connection events in the context of the most extreme space weather events of the last ∼ 150 years is presented. To identify the key factors leading to these extreme events, a sample of the most important geomagnetic storms was selected based mainly on the well-...

  12. Estimate of the upper limit of amplitude of Solar Cycle No. 23

    Energy Technology Data Exchange (ETDEWEB)

    Silbergleit, V. M; Larocca, P. A [Departamento de Fisica, UBA (Argentina)

    2001-07-01

    AA* indices of values greater than 60 10{sup -9} Tesla are considered in order to characterize geomagnetic storms since the available series of these indices comprise the years from 1868 to 1998 (The longest existing interval of geomagnetic activity). By applying the precursor technique we have performed an analysis of the storm periods and the solar activity, obtaining a good correlation between the number of storms ({alpha})(characterized by the AA* indices) and the amplitudes of each solar cycle ({zeta}) and those of the next ({mu}). Using the multiple regression method applied to {alpha}=A+B{zeta} +C{mu}, the constants are calculated and the values found are: A=-33 {+-}18, B= 0.74{+-}0.13 y C= 0.56{+-}0.13. The present statistical method indicates that the current solar cycle (number 23) would have an upper limit of 202{+-}57 monthy mean sunspots. This value indicates that the solar activity would be high causing important effects on the Earth's environment. [Spanish] Se consideran los valores de los indices AA* de valor mayor que 60 10{sup -9} Tesla para caracterizar tormentas geomagneticas ya que las series disponibles de estos indices van desde 1868 hasta 1998 (el mas largo intervalo de la actividad geomagnetica existente). Aplicando la tecnica del precursor hemos realizado un analisis de los periodos de tormentas y la actividad solar obteniendo una buena correlacion entre el numero de tormentas ({alpha}) (caracterizado por los indices AA*) y las amplitudes de los ciclos solares corriente ({zeta}) y el proximo ({mu}). Usando el metodo de regresion multiple aplicado a {alpha}=A+B{zeta} +C{mu}, las consonantes resultaron: A=-33 {+-}18, B= 0.74{+-}0.13 y C= 0.56{+-}0.13. El metodo estadistico presentado indica que el ciclo actual (numero 23) tendria un pico de 202{+-} 57 manchas mensuales promedio. Este valor indica que la actividad solar seria alta produciendo importantes efectos en el medio ambiente terrestre.

  13. Impact of storms on coastlines: preparing for the future without forgetting the past? Examples from European coastlines using a Storm Impact Database

    Science.gov (United States)

    Ciavola, Paolo; Garnier, Emmanuel; Ferreira, Oscar; Spencer, Thomas; Armaroli, Clara

    2017-04-01

    Severe storms have historically affected many European coastlines but the impact of each storm has been evaluated in different ways in different countries, often using local socio-economic impact criteria (e.g. loss of lives and damage to properties). Although the Xynthia (2010) storm, Atlantic coast of France, was the largest coastal disaster of the last 50 years, similar events have previously impacted Europe. The 1953 storm surge in the southern North Sea, resulted in over 2000 deaths and extensive flooding and was the catalyst for post WWII improvements in flood defences and storm early warning systems. On a longer timescale, the very extreme storm of 1634 AD re-configured Wadden Sea coastlines, accompanied by thousands of deaths. Establishing patterns of coastal risk and vulnerability is greatly helped by the use of historical sources, as these allow the development of more complete time series of storm events and their impacts. The work to be presented was supported by the EU RISC-KIT (Resilience-Increasing Strategies for Coasts - toolKIT) Project. RISC-KIT (http://www.risckit.eu/np4/home.html) is a EU FP7 Collaborative project that has developed methods, tools and management approaches to reduce risk and increase resilience to low frequency, high-impact hydro-meteorological events in the coastal zone. These products will enhance forecasting, prediction and early warning capabilities, improve the assessment of long-term coastal risk and optimize the mix of prevention, mitigation and preparedness measures. We analyse historical large-scale events occurred from The Middle Ages to the 1960s at the case study sites of North Norfolk Coast (UK), the Charente-Maritime and Vendée coast (France), the Cinque Terre-Liguria (Italy), the Emilia-Romagna coast (Italy), and the Ria Formosa coast (Portugal). The work presented here uses a database of events built by the project, examining records for the last 300 years, including the characteristics of the storms as well as

  14. Direct observations of atmosphere - sea ice - ocean interactions during Arctic winter and spring storms

    Science.gov (United States)

    Graham, R. M.; Itkin, P.; Granskog, M. A.; Assmy, P.; Cohen, L.; Duarte, P.; Doble, M. J.; Fransson, A.; Fer, I.; Fernandez Mendez, M.; Frey, M. M.; Gerland, S.; Haapala, J. J.; Hudson, S. R.; Liston, G. E.; Merkouriadi, I.; Meyer, A.; Muilwijk, M.; Peterson, A.; Provost, C.; Randelhoff, A.; Rösel, A.; Spreen, G.; Steen, H.; Smedsrud, L. H.; Sundfjord, A.

    2017-12-01

    To study the thinner and younger sea ice that now dominates the Arctic the Norwegian Young Sea ICE expedition (N-ICE2015) was launched in the ice-covered region north of Svalbard, from January to June 2015. During this time, eight local and remote storms affected the region and rare direct observations of the atmosphere, snow, ice and ocean were conducted. Six of these winter storms passed directly over the expedition and resulted in air temperatures rising from below -30oC to near 0oC, followed by abrupt cooling. Substantial snowfall prior to the campaign had already formed a snow pack of approximately 50 cm, to which the February storms contributed an additional 6 cm. The deep snow layer effectively isolated the ice cover and prevented bottom ice growth resulting in low brine fluxes. Peak wind speeds during winter storms exceeded 20 m/s, causing strong snow re-distribution, release of sea salt aerosol and sea ice deformation. The heavy snow load caused widespread negative freeboard; during sea ice deformation events, level ice floes were flooded by sea water, and at least 6-10 cm snow-ice layer was formed. Elevated deformation rates during the most powerful winter storms damaged the ice cover permanently such that the response to wind forcing increased by 60 %. As a result of a remote storm in April deformation processes opened about 4 % of the total area into leads with open water, while a similar amount of ice was deformed into pressure ridges. The strong winds also enhanced ocean mixing and increased ocean heat fluxes three-fold in the pycnocline from 4 to 12 W/m2. Ocean heat fluxes were extremely large (over 300 W/m2) during storms in regions where the warm Atlantic inflow is located close to surface over shallow topography. This resulted in very large (5-25 cm/day) bottom ice melt and in cases flooding due to heavy snow load. Storm events increased the carbon dioxide exchange between the atmosphere and ocean but also affected the pCO2 in surface waters

  15. The effect of solar-geomagnetic activity during hospital admission on coronary events within 1 year in patients with acute coronary syndromes

    Science.gov (United States)

    Vencloviene, J.; Babarskiene, R.; Milvidaite, I.; Kubilius, R.; Stasionyte, J.

    2013-12-01

    Some evidence indicates the deterioration of the cardiovascular system during space storms. It is plausible that the space weather conditions during and after hospital admission may affect the risk of coronary events in patients with acute coronary syndromes (ACS). We analyzed the data of 1400 ACS patients who were admitted to the Hospital Lithuanian University of Health Sciences, and who survived for more than 4 days. We evaluated the associations between geomagnetic storms (GS), solar proton events (SPE), and solar flares (SF) that occurred 0-3 days before and after hospital admission and the risk of cardiovascular death (CAD), non-fatal ACS, and coronary artery bypass grafting (CABG) during a period of 1 year; the evaluation was based on the multivariate logistic model, controlling for clinical data. After adjustment for clinical variables, GS occurring in conjunction with SF 1 day before admission increased the risk of CAD by over 2.5 times. GS 2 days after SPE occurred 1 day after admission increased the risk of CAD and CABG by over 2.8 times. The risk of CABG increased by over 2 times in patients admitted during the day of GS and 1 day after SPE. The risk of ACS was by over 1.63 times higher for patients admitted 1 day before or after solar flares.

  16. Johnston Avenue Solar Project

    Energy Technology Data Exchange (ETDEWEB)

    Schrayer, David [Isles, Inc., Trenton, NJ (United States)

    2017-08-22

    DOE awarded funds to support a demonstration project to illustrate how access to solar power and green roof systems could improve building performance and long-term outcomes for the building owner and multiple nonprofit tenants housed in the building. Since being placed in service the solar PV system has saved approximately $1,000 per month in energy costs. The green roof has added to this benefit by naturally cooling the building and has helped reduce local road flooding by retaining storm water. These elements have improved the quality of life in the low-income community in which the building is located by allowing social service organizations to focus more of their resources on programs and job creation.

  17. How calibration and reference spectra affect the accuracy of absolute soft X-ray solar irradiance measured by the SDO/EVE/ESP during high solar activity

    Science.gov (United States)

    Didkovsky, Leonid; Wieman, Seth; Woods, Thomas

    2016-10-01

    The Extreme ultraviolet Spectrophotometer (ESP), one of the channels of SDO's Extreme ultraviolet Variability Experiment (EVE), measures solar irradiance in several EUV and soft x-ray (SXR) bands isolated using thin-film filters and a transmission diffraction grating, and includes a quad-diode detector positioned at the grating zeroth-order to observe in a wavelength band from about 0.1 to 7.0 nm. The quad diode signal also includes some contribution from shorter wavelength in the grating's first-order and the ratio of zeroth-order to first-order signal depends on both source geometry, and spectral distribution. For example, radiometric calibration of the ESP zeroth-order at the NIST SURF BL-2 with a near-parallel beam provides a different zeroth-to-first-order ratio than modeled for solar observations. The relative influence of "uncalibrated" first-order irradiance during solar observations is a function of the solar spectral irradiance and the locations of large Active Regions or solar flares. We discuss how the "uncalibrated" first-order "solar" component and the use of variable solar reference spectra affect determination of absolute SXR irradiance which currently may be significantly overestimated during high solar activity.

  18. Reading The Sun: A Three Dimensional Visual Model of The Solar Environment During Solar Cycle 24

    Science.gov (United States)

    Carranza-fulmer, T. L.; Moldwin, M.

    2014-12-01

    The sun is a powerful force that has proven to our society that it has a large impact on our lives. Unfortunately, there is still a lack of awareness on how the sun is capable of affecting Earth. The over all idea of "Reading The Sun" installation is to help demonstrate how the sun impacts the Earth, by compiling various data sources from satellites (SOHO, SDO, and STERO) with solar and solar wind models (MAS and ENLIL) to create a comprehensive three dimensional display of the solar environment. It focuses on the current solar maximum of solar cycle 24 and a CME that impacted Earth's magnetic field on February 27, 2014, which triggered geomagnetic storms around the Earth's poles. The CME was an after-effect of a class X4.9 solar flare, which was released from the sun on February 25, 2014. "Reading The Sun" is a 48" x 48" x 48" hanging model of the sun with color coded open opposing magnetic field lines along with various layers of the solar atmosphere, the heliospheric current sheet, and the inner planets. At the center of the xyz axis is the sun with the open magnetic field lines and the heliospheric current sheet permeating inner planetary space. The xyz axes are color coded to represent various types of information with corresponding visual images for the viewer to be able to read the model. Along the z-axis are three colors (yellow, orange, and green) that represent the different layers of the solar atmosphere (photosphere, chromosphere, and corona) that correspond to three satellite images in various spectrums related to a CME and Solar Flare and the xy-plane shows where the inner planets are in relation to the sun. The exhibit in which "Reading The Sun "is being displayed is called, The Rotation of Language at the Wheather Again Gallery in Rockaway, New York. The intent of the exhibit is to both celebrate as well as present a cautionary tale on the ability of human language to spark and ignite the individual and collective imagination towards an experience

  19. Solar-terrestrial disturbances of June-September 1982, 4

    International Nuclear Information System (INIS)

    Watanabe, Shigeaki; Ondoh, Tadanori

    1985-01-01

    Several ion whistlers were observed by the polar orbiting satellites, ISIS's during geomagnetic storms associated with large solar flares in 1982. It seems that the proton density ratio to the total ions deduced from the crossover frequency of the trans-equatorial ion whistlers observed at geomagnetic low latitudes during the main phase of the geomagnetic storm on July 14th 1982 was lower than the usual density rate. An abnormal pattern seen on the time-compressed dynamic spectra for September 6 th 1982 suggests existence of effects by the component 3 He + in a quite small amount. (author)

  20. The storm time ring current dynamics and response to CMEs and CIRs using Van Allen Probes observations and CIMI simulations

    Science.gov (United States)

    Mouikis, Christopher; Bingham, Samuel; Kistler, Lynn; Spence, Harlan; Gkioulidou, Matina

    2017-04-01

    The ring current responds differently to the different solar and interplanetary storm drivers such as coronal mass injections, (CME's), and co-rotating interaction regions (CIR's). Using Van Allen Probes observations, we develop an empirical ring current model of the ring current pressure, the pressure anisotropy and the current density development during the storm phases for both types of storm drivers and for all MLTs inside L 6. Delineating the differences in the ring current development between these two drivers will aid our understanding of the ring current dynamics. We find that during the storm main phase most of the ring current pressure in the pre-midnight inner magnetosphere is contributed by particles on open drift paths that cause the development of a strong partial ring current that causes most of the main phase Dst drop. These particles can reach as deep as L 2 and their pressure compares to the local magnetic field pressure as deep as L 3. During the recovery phase, if these particles are not lost at the magnetopause, will become trapped and will contribute to the symmetric ring current. However, the largest difference between the CME and CIR ring current responses during the storm main and early recovery phases is caused by how the 15 - 60 keV O+ responds to these drivers. This empirical model is compared to the results of CIMI simulations of a CMEs and a CIRs where the model input is comprised of the superposed epoch solar wind conditions of the storms that comprise the empirical model. Different inner magnetosphere boundary conditions are tested in order to match the empirical model results. Comparing the model and simulation results improves our understanding of the ring current dynamics as part of the highly coupled inner magnetosphere system. In addition, within the framework of this empirical model, the prediction of the EMIC wave generation linear theory is tested using the observed plasma parameters and comparing with the observations of

  1. The Complex Relationship Between Heavy Storms and Floods: Implication on Stormwater Drainage design and Management

    Science.gov (United States)

    Demissie, Y.; Mortuza, M. R.; Moges, E.; Yan, E.; Li, H. Y.

    2017-12-01

    Due to the lack of historical and future streamflow data for flood frequency analysis at or near most drainage sites, it is a common practice to directly estimate the design flood (maximum discharge or volume of stream for a given return period) based on storm frequency analysis and the resulted Intensity-Duration-Frequency (IDF) curves. Such analysis assumes a direct relationship between storms and floods with, for example, the 10-year rainfall expected to produce the 10-year flood. However, in reality, a storm is just one factor among the many other hydrological and metrological factors that can affect the peak flow and hydrograph. Consequently, a heavy storm does not necessarily always lead to flooding or a flood events with the same frequency. This is evident by the observed difference in the seasonality of heavy storms and floods in most regions. In order to understand site specific causal-effect relationship between heavy storms and floods and improve the flood analysis for stormwater drainage design and management, we have examined the contributions of various factors that affect floods using statistical and information theory methods. Based on the identified dominant causal-effect relationships, hydrologic and probability analyses were conducted to develop the runoff IDF curves taking into consideration the snowmelt and rain-on-snow effect, the difference in the storm and flood seasonality, soil moisture conditions, and catchment potential for flash and riverine flooding. The approach was demonstrated using data from military installations located in different parts of the United States. The accuracy of the flood frequency analysis and the resulted runoff IDF curves were evaluated based on the runoff IDF curves developed from streamflow measurements.

  2. Assessing storm events for energy meteorology: using media and scientific reports to track a North Sea autumn storm.

    Science.gov (United States)

    Kettle, Anthony

    2016-04-01

    Important issues for energy meteorology are to assess meteorological conditions for normal operating conditions and extreme events for the ultimate limit state of engineering structures. For the offshore environment in northwest Europe, energy meteorology encompasses weather conditions relevant for petroleum production infrastructure and also the new field of offshore wind energy production. Autumn and winter storms are an important issue for offshore operations in the North Sea. The weather in this region is considered as challenging for extreme meteorological events as the Gulf of Mexico with its attendant hurricane risk. The rise of the Internet and proliferation of digital recording devices has placed a much greater amount of information in the public domain than was available to national meteorological agencies even 20 years ago. This contribution looks at reports of meteorology and infrastructure damage from a storm in the autumn of 2006 to trace the spatial and temporal record of meteorological events. Media reports give key information to assess the events of the storm. The storm passed over northern Europe between Oct.31-Nov. 2, 2006, and press reports from the time indicate that its most important feature was a high surge that inundated coastal areas. Sections of the Dutch and German North Sea coast were affected, and there was record flooding in Denmark and East Germany in the southern Baltic Sea. Extreme wind gusts were also reported that were strong enough to damage roofs and trees, and there was even tornado recorded near the Dutch-German border. Offshore, there were a series of damage reports from ship and platforms that were linked with sea state, and reports of rogue waves were explicitly mentioned. Many regional government authorities published summaries of geophysical information related to the storm, and these form part of a regular series of online winter storm reports that started as a public service about 15 years ago. Depending on the

  3. Modeling urban storm rainfall runoff from diverse underlying surfaces and application for control design in Beijing.

    Science.gov (United States)

    Ouyang, Wei; Guo, Bobo; Hao, Fanghua; Huang, Haobo; Li, Junqi; Gong, Yongwei

    2012-12-30

    Managing storm rainfall runoff is paramount in semi-arid regions with urban development. In Beijing, pollution prevention in urban storm runoff and storm water utilization has been identified as the primary strategy for urban water management. In this paper, we sampled runoff during storm rainfall events and analyzed the concentration of chemical oxygen demand (COD), total suspended solids (TSS) and total phosphorus (TP) in the runoff. Furthermore, the first flush effect of storm rainfall from diverse underlying surfaces was also analyzed. With the Storm Water Management Model (SWMM), the different impervious rates of underlying surfaces during the storm runoff process were expressed. The removal rates of three typical pollutants and their interactions with precipitation and underlying surfaces were identified. From these rates, the scenarios regarding the urban storm runoff pollution loading from different designs of underlying previous rates were assessed with the SWMM. First flush effect analysis showed that the first 20% of the storm runoff should be discarded, which can help in utilizing the storm water resource. The results of this study suggest that the SWMM can express in detail the storm water pollution patterns from diverse underlying surfaces in Beijing, which significantly affected water quality. The scenario analysis demonstrated that impervious rate adjustment has the potential to reduce runoff peak and decrease pollution loading. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Thromboembolic complications of thyroid storm.

    Science.gov (United States)

    Min, T; Benjamin, S; Cozma, L

    2014-01-01

    Thyroid storm is a rare but potentially life-threatening complication of hyperthyroidism. Early recognition and prompt treatment are essential. Atrial fibrillation can occur in up to 40% of patients with thyroid storm. Studies have shown that hyperthyroidism increases the risk of thromboembolic events. There is no consensus with regard to the initiation of anticoagulation for atrial fibrillation in severe thyrotoxicosis. Anticoagulation is not routinely initiated if the risk is low on a CHADS2 score; however, this should be considered in patients with thyroid storm or severe thyrotoxicosis with impending storm irrespective of the CHADS2 risk, as it appears to increase the risk of thromboembolic episodes. Herein, we describe a case of thyroid storm complicated by massive pulmonary embolism. Diagnosis of thyroid storm is based on clinical findings. Early recognition and prompt treatment could lead to a favourable outcome.Hypercoagulable state is a recognised complication of thyrotoxicosis.Atrial fibrillation is strongly associated with hyperthyroidism and thyroid storm.Anticoagulation should be considered for patients with severe thyrotoxicosis and atrial fibrillation irrespective of the CHADS2 score.Patients with severe thyrotoxicosis and clinical evidence of thrombosis should be immediately anticoagulated until hyperthyroidism is under control.

  5. Impacts on coralligenous outcrop biodiversity of a dramatic coastal storm.

    Directory of Open Access Journals (Sweden)

    Núria Teixidó

    Full Text Available Extreme events are rare, stochastic perturbations that can cause abrupt and dramatic ecological change within a short period of time relative to the lifespan of organisms. Studies over time provide exceptional opportunities to detect the effects of extreme climatic events and to measure their impacts by quantifying rates of change at population and community levels. In this study, we show how an extreme storm event affected the dynamics of benthic coralligenous outcrops in the NW Mediterranean Sea using data acquired before (2006-2008 and after the impact (2009-2010 at four different sites. Storms of comparable severity have been documented to occur occasionally within periods of 50 years in the Mediterranean Sea. We assessed the effects derived from the storm comparing changes in benthic community composition at sites exposed to and sheltered from this extreme event. The sites analyzed showed different damage from severe to negligible. The most exposed and impacted site experienced a major shift immediately after the storm, represented by changes in the species richness and beta diversity of benthic species. This site also showed higher compositional variability immediately after the storm and over the following year. The loss of cover of benthic species resulted between 22% and 58%. The damage across these species (e.g. calcareous algae, sponges, anthozoans, bryozoans, tunicates was uneven, and those with fragile forms were the most impacted, showing cover losses up to 50 to 100%. Interestingly, small patches survived after the storm and began to grow slightly during the following year. In contrast, sheltered sites showed no significant changes in all the studied parameters, indicating no variations due to the storm. This study provides new insights into the responses to large and rare extreme events of Mediterranean communities with low dynamics and long-lived species, which are among the most threatened by the effects of global change.

  6. The effect of severe storms on the ice cover of the northern Tatarskiy Strait

    Science.gov (United States)

    Martin, Seelye; Munoz, Esther; Drucker, Robert

    1992-01-01

    Passive microwave images from the Special Sensor Microwave Imager are used to study the volume of ice and sea-bottom water in the Japan Sea as affected by winds and severe storms. The data set comprises brightness temperatures gridded on a polar stereographic projection, and the processing is accomplished with a linear algorithm by Cavalieri et al. (1983) based on the vertically polarized 37-GHz channel. The expressions for calculating heat fluxes and downwelling radiation are given, and ice-cover fluctuations are correlated with severe storm events. The storms generate large transient polynya that occur simultaneously with the strongest heat fluxes, and severe storms are found to contribute about 25 percent of the annual introduction of 25 cu km of ice in the region. The ice production could lead to the renewal of enough sea-bottom water to account for the C-14 data provided, and the generation of Japan Sea bottom water is found to vary directly with storm activity.

  7. Severe geomagnetic storms and Forbush decreases: interplanetary relationships reexamined

    Directory of Open Access Journals (Sweden)

    R. P. Kane

    2010-02-01

    Full Text Available Severe storms (Dst and Forbush decreases (FD during cycle 23 showed that maximum negative Dst magnitudes usually occurred almost simultaneously with the maximum negative values of the Bz component of interplanetary magnetic field B, but the maximum magnitudes of negative Dst and Bz were poorly correlated (+0.28. A parameter Bz(CP was calculated (cumulative partial Bz as sum of the hourly negative values of Bz from the time of start to the maximum negative value. The correlation of negative Dst maximum with Bz(CP was higher (+0.59 as compared to that of Dst with Bz alone (+0.28. When the product of Bz with the solar wind speed V (at the hour of negative Bz maximum was considered, the correlation of negative Dst maximum with VBz was +0.59 and with VBz(CP, 0.71. Thus, including V improved the correlations. However, ground-based Dst values have a considerable contribution from magnetopause currents (several tens of nT, even exceeding 100 nT in very severe storms. When their contribution is subtracted from Dst(nT, the residue Dst* representing true ring current effect is much better correlated with Bz and Bz(CP, but not with VBz or VBz(CP, indicating that these are unimportant parameters and the effect of V is seen only through the solar wind ram pressure causing magnetopause currents. Maximum negative Dst (or Dst* did not occur at the same hour as maximum FD. The time evolutions of Dst and FD were very different. The correlations were almost zero. Basically, negative Dst (or Dst* and FDs are uncorrelated, indicating altogether different mechanism.

  8. Effects of cluster land reclamation projects on storm surge in Jiaojiang Estuary, China

    Directory of Open Access Journals (Sweden)

    Zhi-lin Sun

    2017-01-01

    Full Text Available Variations in coastline geometry caused by coastal engineering affect tides, storm surges, and storm tides. Three cluster land reclamation projects have been planned for construction in the Jiaojiang Estuary during the period from 2011 to 2023. They will cause significant changes in coastline geometry. In this study, a surge-tide coupled model was established based on a three-dimensional finite-volume coastal ocean model (FVCOM. A series of numerical experiments were carried out to investigate the effects of variations in coastline geometry on tides, storm surges, and storm tides. This model was calibrated using data observed at the Haimen and Ruian gauge stations and then used to reproduce the tides, storm surges, and storm tides in the Jiaojiang Estuary caused by Typhoon Winnie in 1997. Results show that the high tide level, peak storm surge, and high storm tide level at the Haimen Gauge Station increased along with the completion of reclamation projects, and the maximum increments caused by the third project were 0.13 m, 0.50 m, and 0.43 m, respectively. The envelopes with maximum storm tide levels of 7.0 m and 8.0 m inside the river mouth appeared to move seaward, with the latter shifting 1.8 km, 3.3 km, and 4.4 km due to the first project, second project, and third project, respectively. The results achieved in this study contribute to reducing the effects of, and preventing storm disasters after the land reclamation in the Jiaojiang Estuary.

  9. Perfect storm: Therapeutic plasma exchange for a patient with thyroid storm.

    Science.gov (United States)

    McGonigle, Andrea M; Tobian, Aaron A R; Zink, Jennifer L; King, Karen E

    2018-02-01

    Thyroid storm is a potentially lethal complication of hyperthyroidism with increased thyroid hormones and exaggerated symptoms of thyrotoxicosis. First-line therapy includes methimazole (MMI) or propylthiouracil (PTU) to block production of thyroid hormones as a bridge toward definitive surgical treatment. Untreated thyroid storm has a mortality rate of up to 30%; this is particularly alarming when patients cannot tolerate or fail pharmacotherapy, especially if they cannot undergo thyroidectomy. Therapeutic plasma exchange (TPE) is an ASFA category III indication for thyroid storm, meaning the optimum role of this therapy is not established, and there are a limited number of cases in the literature. Yet TPE can remove T3 and T4 bound to albumin, autoantibodies, catecholamines and cytokines and is likely beneficial for these patients. We report a patient with thyroid storm who could not tolerate PTU, subsequently failed therapy with MMI, and was not appropriate for thyroidectomy. TPE was therefore performed daily for 4 days (1.0 plasma volume with 5% albumin replacement and 2 U of plasma). Over the treatment course, the patient's thyroid hormones normalized and symptoms of thyroid storm largely resolved; his T3 decreased from 2.27 to 0.81 ng/mL (normal 0.8-2.0), T4 decreased from 4.8 to 1.7 ng/mL (0.8-1.8), heart rate normalized, altered mental status improved, and he converted to normal sinus rhythm. He was ultimately discharged in euthyroid state. He experienced no side effects from his TPE procedures. TPE is a safe and effective treatment for thyroid storm when conventional treatments are not successful or appropriate. © 2017 Wiley Periodicals, Inc.

  10. Modeling and simulation of storm surge on Staten Island to understand inundation mitigation strategies

    Science.gov (United States)

    Kress, Michael E.; Benimoff, Alan I.; Fritz, William J.; Thatcher, Cindy A.; Blanton, Brian O.; Dzedzits, Eugene

    2016-01-01

    Hurricane Sandy made landfall on October 29, 2012, near Brigantine, New Jersey, and had a transformative impact on Staten Island and the New York Metropolitan area. Of the 43 New York City fatalities, 23 occurred on Staten Island. The borough, with a population of approximately 500,000, experienced some of the most devastating impacts of the storm. Since Hurricane Sandy, protective dunes have been constructed on the southeast shore of Staten Island. ADCIRC+SWAN model simulations run on The City University of New York's Cray XE6M, housed at the College of Staten Island, using updated topographic data show that the coast of Staten Island is still susceptible to tidal surge similar to those generated by Hurricane Sandy. Sandy hindcast simulations of storm surges focusing on Staten Island are in good agreement with observed storm tide measurements. Model results calculated from fine-scaled and coarse-scaled computational grids demonstrate that finer grids better resolve small differences in the topography of critical hydraulic control structures, which affect storm surge inundation levels. The storm surge simulations, based on post-storm topography obtained from high-resolution lidar, provide much-needed information to understand Staten Island's changing vulnerability to storm surge inundation. The results of fine-scale storm surge simulations can be used to inform efforts to improve resiliency to future storms. For example, protective barriers contain planned gaps in the dunes to provide for beach access that may inadvertently increase the vulnerability of the area.

  11. Unexpected Southern Hemisphere ionospheric response to geomagnetic storm of 15 August 2015

    Science.gov (United States)

    Edemskiy, Ilya; Lastovicka, Jan; Buresova, Dalia; Bosco Habarulema, John; Nepomnyashchikh, Ivan

    2018-01-01

    Geomagnetic storms are the most pronounced phenomenon of space weather. When studying ionospheric response to a storm of 15 August 2015, an unexpected phenomenon was observed at higher middle latitudes of the Southern Hemisphere. This phenomenon was a localized total electron content (TEC) enhancement (LTE) in the form of two separated plumes, which peaked southward of South Africa. The plumes were first observed at 05:00 UT near the southwestern coast of Australia. The southern plume was associated with local time slightly after noontime (1-2 h after local noon). The plumes moved with the Sun. They peaked near 13:00 UT southward of South Africa. The southern plume kept constant geomagnetic latitude (63-64° S); it persisted for about 10 h, whereas the northern plume persisted for about 2 h more. Both plumes disappeared over the South Atlantic Ocean. No similar LTE event was observed during the prolonged solar activity minimum period of 2006-2009. In 2012-2016 we detected altogether 26 LTEs and all of them were associated with the southward excursion of Bz. The negative Bz excursion is a necessary but not sufficient condition for the LTE occurrence as during some geomagnetic storms associated with negative Bz excursions the LTE events did not appear.

  12. Field-aligned currents observed by CHAMP during the intense 2003 geomagnetic storm events

    Directory of Open Access Journals (Sweden)

    H. Wang

    2006-03-01

    Full Text Available This study concentrates on the characteristics of field-aligned currents (FACs in both hemispheres during the extreme storms in October and November 2003. High-resolution CHAMP magnetic data reflect the dynamics of FACs during these geomagnetic storms, which are different from normal periods. The peak intensity and most equatorward location of FACs in response to the storm phases are examined separately for both hemispheres, as well as for the dayside and nightside. The corresponding large-scale FAC peak densities are, on average, enhanced by about a factor of 5 compared to the quiet-time FACs' strengths. And the FAC densities on the dayside are, on average, 2.5 times larger in the Southern (summer than in the Northern (winter Hemisphere, while the observed intensities on the nightside are comparable between the two hemispheres. Solar wind dynamic pressure is correlated with the FACs strength on the dayside. However, the latitudinal variations of the FACs are compared with the variations in Dst and the interplanetary magnetic field component Bz, in order to determine how these parameters control the large-scale FACs' configuration in the polar region. We have determined that (1 the equatorward shift of FACs on the dayside is directly controlled by the southward IMF Bz and there is a saturation of the latitudinal displacement for large value of negative Bz. In the winter hemisphere this saturation occurs at higher latitudes than in the summer hemisphere. (2 The equatorward expansion of the nightside FACs is delayed with respect to the solar wind input. The poleward recovery of FACs on the nightside is slower than on the dayside. The latitudinal variations on the nightside are better described by the variations of the Dst index. (3 The latitudinal width of the FAC region on the nightside spreads over a wide range of about 25° in latitude.

  13. Barrier island morphology and sediment characteristics affect the recovery of dune building grasses following storm-induced overwash.

    Science.gov (United States)

    Brantley, Steven T; Bissett, Spencer N; Young, Donald R; Wolner, Catherine W V; Moore, Laura J

    2014-01-01

    Barrier islands are complex and dynamic systems that provide critical ecosystem services to coastal populations. Stability of these systems is threatened by rising sea level and the potential for coastal storms to increase in frequency and intensity. Recovery of dune-building grasses following storms is an important process that promotes topographic heterogeneity and long-term stability of barrier islands, yet factors that drive dune recovery are poorly understood. We examined vegetation recovery in overwash zones on two geomorphically distinct (undisturbed vs. frequently overwashed) barrier islands on the Virginia coast, USA. We hypothesized that vegetation recovery in overwash zones would be driven primarily by environmental characteristics, especially elevation and beach width. We sampled species composition and environmental characteristics along a continuum of disturbance from active overwash zones to relict overwash zones and in adjacent undisturbed environments. We compared species assemblages along the disturbance chronosequence and between islands and we analyzed species composition data and environmental measurements with Canonical Correspondence Analysis to link community composition with environmental characteristics. Recovering and geomorphically stable dunes were dominated by Ammophila breviligulata Fernaud (Poaceae) on both islands while active overwash zones were dominated by Spartina patens (Aiton) Muhl. (Poaceae) on the frequently disturbed island and bare sand on the less disturbed island. Species composition was associated with environmental characteristics only on the frequently disturbed island (p = 0.005) where A. breviligulata was associated with higher elevation and greater beach width. Spartina patens, the second most abundant species, was associated with larger sediment grain size and greater sediment size distribution. On the less frequently disturbed island, time since disturbance was the only factor that affected community

  14. Barrier island morphology and sediment characteristics affect the recovery of dune building grasses following storm-induced overwash.

    Directory of Open Access Journals (Sweden)

    Steven T Brantley

    Full Text Available Barrier islands are complex and dynamic systems that provide critical ecosystem services to coastal populations. Stability of these systems is threatened by rising sea level and the potential for coastal storms to increase in frequency and intensity. Recovery of dune-building grasses following storms is an important process that promotes topographic heterogeneity and long-term stability of barrier islands, yet factors that drive dune recovery are poorly understood. We examined vegetation recovery in overwash zones on two geomorphically distinct (undisturbed vs. frequently overwashed barrier islands on the Virginia coast, USA. We hypothesized that vegetation recovery in overwash zones would be driven primarily by environmental characteristics, especially elevation and beach width. We sampled species composition and environmental characteristics along a continuum of disturbance from active overwash zones to relict overwash zones and in adjacent undisturbed environments. We compared species assemblages along the disturbance chronosequence and between islands and we analyzed species composition data and environmental measurements with Canonical Correspondence Analysis to link community composition with environmental characteristics. Recovering and geomorphically stable dunes were dominated by Ammophila breviligulata Fernaud (Poaceae on both islands while active overwash zones were dominated by Spartina patens (Aiton Muhl. (Poaceae on the frequently disturbed island and bare sand on the less disturbed island. Species composition was associated with environmental characteristics only on the frequently disturbed island (p = 0.005 where A. breviligulata was associated with higher elevation and greater beach width. Spartina patens, the second most abundant species, was associated with larger sediment grain size and greater sediment size distribution. On the less frequently disturbed island, time since disturbance was the only factor that affected

  15. Photovoltaic commercialization: an analysis of legal issues affecting a government-accelerated solar industry

    Energy Technology Data Exchange (ETDEWEB)

    Lamm, D.

    1980-06-01

    The Photovoltaics Research, Development, and Demonstration Act of 1978 is discussed. Legal issues, including solar access, the need for performance standards, the effects of building codes on photovoltaic system use and commercialization, and manufacturer and installer performance guarantees, are examined. Electric utility policies are examined, including interconnection, and rates and legal issues affecting them. (LEW)

  16. Factors controlling storm impacts on coastal barriers and beaches - A preliminary basis for near real-time forecasting

    Science.gov (United States)

    Morton, R.A.

    2002-01-01

    Analysis of ground conditions and meteorological and oceanographic parameters for some of the most severe Atlantic and Gulf Coast storms in the U.S. reveals the primary factors affecting morphological storm responses of beaches and barrier islands. The principal controlling factors are storm characteristics, geographic position relative to storm path, timing of storm events, duration of wave exposure, wind stress, degree of flow confinement, antecedent topography and geologic framework, sediment textures, vegetative cover, and type and density of coastal development. A classification of commonly observed storm responses demonstrates the sequential interrelations among (1) land elevations, (2) water elevations in the ocean and adjacent lagoon (if present), and (3) stages of rising water during the storm. The predictable coastal responses, in relative order from high frequency beach erosion to low frequency barrier inundation, include: beach erosion, berm migration, dune erosion, washover terrace construction, perched fan deposition, sheetwash, washover channel incision, washout formation, and forced and unforced ebb flow. Near real-time forecasting of expected storm impacts is possible if the following information is available for the coast: a detailed morphological and topographic characterization, accurate storm-surge and wave-runup models, the real-time reporting of storm parameters, accurate forecasts of the storm position relative to a particular coastal segment, and a conceptual model of geological processes that encompasses observed morphological changes caused by extreme storms.

  17. The application of microtextural and heavy mineral analysis to discriminate between storm and tsunami deposits

    Science.gov (United States)

    Costa, Pedro J.M.; Gelfenbaum, Guy R.; Dawson, Sue; La selle, Seanpaul; Milne, F; Cascalho, J.; Ponte Lira, C.; Andrade, C.; Freitas, M. C.; Jaffe, Bruce E.

    2017-01-01

    Recent work has applied microtextural and heavy mineral analyses to sandy storm and tsunami deposits from Portugal, Scotland, Indonesia and the USA. We looked at the interpretation of microtextural imagery (scanning electron microscopy) of quartz grains and heavy mineral compositions. We consider inundation events of different chronologies and sources (the AD 1755 Lisbon and 2004 Indian Ocean tsunamis, the Great Storm of 11 January 2005 in Scotland, and Hurricane Sandy in 2012) that affected contrasting coastal and hinterland settings with different regional oceanographic conditions. Storm and tsunami deposits were examined along with potential source sediments (alluvial, beach, dune and nearshore sediments) to determine provenance.Results suggest that tsunami deposits typically exhibit a significant spatial variation in grain sizes, microtextures and heavy minerals. Storm deposits show less variability, especially in vertical profiles. Tsunami and storm quartz grains had more percussion marks and fresh surfaces compared to potential source material. Moreover, in the studied cases, tsunami samples had fewer fresh surfaces than storm deposits.Heavy mineral assemblages are typically site-specific. The concentration of heavy minerals decreases upwards in tsunamigenic units, whereas storm sediments show cyclic concentrations of heavy minerals, reflected in the laminations observed macroscopically in the deposits.

  18. Relationship between substorms and storms

    International Nuclear Information System (INIS)

    Kamide, Y.

    1980-01-01

    In an attempt to deduce a plausible working model of the relationship between magnetospheric substorms and storms, recent relevant studies of various processes occurring during disturbed periods are integrated along with some theoretical suggestions. It has been shown that the main phase of geomagnetic storms is associated with the successive occurrence of intense substorms and with the sustained southward component of the interplanetary magnetic field (IMF). However, these relations are only qualitatively understood, and thus basic questions remain unanswered involving the hypothesis whether a magnetic storm is a non-linear (or linear) superposition of intense substorms, each of which constitutes an elementary storm, or the main phase of magnetic storms occurs as a result of the intense southward IMF which enhances magnetospheric convection and increases occurrence probability of substorms. (Auth.)

  19. Detection of Asian Dust Storm Using MODIS Measurements

    Directory of Open Access Journals (Sweden)

    Yong Xie

    2017-08-01

    Full Text Available Every year, a large number of aerosols are released from dust storms into the atmosphere, which may have potential impacts on the climate, environment, and air quality. Detecting dust aerosols and monitoring their movements and evolutions in a timely manner is a very significant task. Satellite remote sensing has been demonstrated as an effective means for observing dust aerosols. In this paper, an algorithm based on the multi-spectral technique for detecting dust aerosols was developed by combining measurements of moderate resolution imaging spectroradiometer (MODIS reflective solar bands and thermal emissive bands. Data from dust events that occurred during the past several years were collected as training data for spectral and statistical analyses. According to the spectral curves of various scene types, a series of spectral bands was selected individually or jointly, and corresponding thresholds were defined for step-by-step scene classification. The multi-spectral algorithm was applied mainly to detect dust storms in Asia. The detection results were validated not only visually with MODIS true color images, but also quantitatively with products of Ozone Monitoring Instrument (OMI and Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP. The validations showed that this multi-spectral detection algorithm was suitable to monitor dust aerosols in the selected study areas.

  20. Probabilistic storm surge inundation maps for Metro Manila based on Philippine public storm warning signals

    Science.gov (United States)

    Tablazon, J.; Caro, C. V.; Lagmay, A. M. F.; Briones, J. B. L.; Dasallas, L.; Lapidez, J. P.; Santiago, J.; Suarez, J. K.; Ladiero, C.; Gonzalo, L. A.; Mungcal, M. T. F.; Malano, V.

    2015-03-01

    A storm surge is the sudden rise of sea water over the astronomical tides, generated by an approaching storm. This event poses a major threat to the Philippine coastal areas, as manifested by Typhoon Haiyan on 8 November 2013. This hydro-meteorological hazard is one of the main reasons for the high number of casualties due to the typhoon, with 6300 deaths. It became evident that the need to develop a storm surge inundation map is of utmost importance. To develop these maps, the Nationwide Operational Assessment of Hazards under the Department of Science and Technology (DOST-Project NOAH) simulated historical tropical cyclones that entered the Philippine Area of Responsibility. The Japan Meteorological Agency storm surge model was used to simulate storm surge heights. The frequency distribution of the maximum storm surge heights was calculated using simulation results of tropical cyclones under a specific public storm warning signal (PSWS) that passed through a particular coastal area. This determines the storm surge height corresponding to a given probability of occurrence. The storm surge heights from the model were added to the maximum astronomical tide data from WXTide software. The team then created maps of inundation for a specific PSWS using the probability of exceedance derived from the frequency distribution. Buildings and other structures were assigned a probability of exceedance depending on their occupancy category, i.e., 1% probability of exceedance for critical facilities, 10% probability of exceedance for special occupancy structures, and 25% for standard occupancy and miscellaneous structures. The maps produced show the storm-surge-vulnerable areas in Metro Manila, illustrated by the flood depth of up to 4 m and extent of up to 6.5 km from the coastline. This information can help local government units in developing early warning systems, disaster preparedness and mitigation plans, vulnerability assessments, risk-sensitive land use plans, shoreline

  1. NCDC Storm Events Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Storm Data is provided by the National Weather Service (NWS) and contain statistics on personal injuries and damage estimates. Storm Data covers the United States of...

  2. Analysis of the positive ionospheric response to a moderate geomagnetic storm using a global numerical model

    Directory of Open Access Journals (Sweden)

    A. A. Namgaladze

    2000-04-01

    Full Text Available Current theories of F-layer storms are discussed using numerical simulations with the Upper Atmosphere Model, a global self-consistent, time dependent numerical model of the thermosphere-ionosphere-plasmasphere-magnetosphere system including electrodynamical coupling effects. A case study of a moderate geomagnetic storm at low solar activity during the northern winter solstice exemplifies the complex storm phenomena. The study focuses on positive ionospheric storm effects in relation to thermospheric disturbances in general and thermospheric composition changes in particular. It investigates the dynamical effects of both neutral meridional winds and electric fields caused by the disturbance dynamo effect. The penetration of short-time electric fields of magnetospheric origin during storm intensification phases is shown for the first time in this model study. Comparisons of the calculated thermospheric composition changes with satellite observations of AE-C and ESRO-4 during storm time show a good agreement. The empirical MSISE90 model, however, is less consistent with the simulations. It does not show the equatorward propagation of the disturbances and predicts that they have a gentler latitudinal gradient. Both theoretical and experimental data reveal that although the ratio of [O]/[N2] at high latitudes decreases significantly during the magnetic storm compared with the quiet time level, at mid to low latitudes it does not increase (at fixed altitudes above the quiet reference level. Meanwhile, the ionospheric storm is positive there. We conclude that the positive phase of the ionospheric storm is mainly due to uplifting of ionospheric F2-region plasma at mid latitudes and its equatorward movement at low latitudes along geomagnetic field lines caused by large-scale neutral wind circulation and the passage of travelling atmospheric disturbances (TADs. The calculated zonal electric field disturbances also help to create the positive ionospheric

  3. Analysis of the positive ionospheric response to a moderate geomagnetic storm using a global numerical model

    Directory of Open Access Journals (Sweden)

    A. A. Namgaladze

    Full Text Available Current theories of F-layer storms are discussed using numerical simulations with the Upper Atmosphere Model, a global self-consistent, time dependent numerical model of the thermosphere-ionosphere-plasmasphere-magnetosphere system including electrodynamical coupling effects. A case study of a moderate geomagnetic storm at low solar activity during the northern winter solstice exemplifies the complex storm phenomena. The study focuses on positive ionospheric storm effects in relation to thermospheric disturbances in general and thermospheric composition changes in particular. It investigates the dynamical effects of both neutral meridional winds and electric fields caused by the disturbance dynamo effect. The penetration of short-time electric fields of magnetospheric origin during storm intensification phases is shown for the first time in this model study. Comparisons of the calculated thermospheric composition changes with satellite observations of AE-C and ESRO-4 during storm time show a good agreement. The empirical MSISE90 model, however, is less consistent with the simulations. It does not show the equatorward propagation of the disturbances and predicts that they have a gentler latitudinal gradient. Both theoretical and experimental data reveal that although the ratio of [O]/[N2] at high latitudes decreases significantly during the magnetic storm compared with the quiet time level, at mid to low latitudes it does not increase (at fixed altitudes above the quiet reference level. Meanwhile, the ionospheric storm is positive there. We conclude that the positive phase of the ionospheric storm is mainly due to uplifting of ionospheric F2-region plasma at mid latitudes and its equatorward movement at low latitudes along geomagnetic field lines caused by large-scale neutral wind circulation and the passage of travelling atmospheric disturbances (TADs. The calculated zonal electric field disturbances also help

  4. Evaluation of the STORM model storm-time corrections for middle latitude

    Czech Academy of Sciences Publication Activity Database

    Burešová, Dalia; McKinnell, L.- A.; Šindelářová, Tereza; de la Morena, B. A.

    2010-01-01

    Roč. 46, č. 8 (2010), s. 1039-1046 ISSN 0273-1177 R&D Projects: GA ČR GA205/08/1356; GA AV ČR 1QS300120506 Institutional research plan: CEZ:AV0Z30420517 Keywords : Ionosphere * Geomagnetic storms * STORM model * International Reference Ionosphere (IRI) Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.076, year: 2010

  5. Predicting severe winter coastal storm damage

    International Nuclear Information System (INIS)

    Hondula, David M; Dolan, Robert

    2010-01-01

    Over the past 40 years residents of, and visitors to, the North Carolina coastal barrier islands have experienced the destructive forces of several 'named' extratropical storms. These storms have caused large-scale redistributions of sand and loss of coastal structures and infrastructure. While most of the population living on the islands are familiar with the wintertime storms, the damage and scars of the 'super northeasters'-such as the Ash Wednesday storm of 7 March 1962, and the Halloween storm of 1989-are slipping away from the public's memory. In this research we compared the damage zones of the 1962 Ash Wednesday storm, as depicted on aerial photographs taken after the storm, with photos taken of the same areas in 2003. With these high-resolution aerial photos we were able to estimate the extent of new development which has taken place along the Outer Banks of North Carolina since 1962. Three damage zones were defined that extend across the islands from the ocean landward on the 1962 aerial photos: (1) the zone of almost total destruction on the seaward edge of the islands where the storm waves break; (2) the zone immediately inland where moderate structural damage occurs during severe storms; and (3) the zone of flood damage at the landward margin of the storm surge and overwash. We considered the rate of coastal erosion, the rate of development, and increases in property values as factors which may contribute to changing the financial risk for coastal communities. In comparing the values of these four factors with the 1962 damage data, we produced a predicted dollar value for storm damage should another storm of the magnitude of the 1962 Ash Wednesday storm occur in the present decade. This model also provides an opportunity to estimate the rate of increase in the potential losses through time as shoreline erosion continues to progressively reduce the buffer between the development and the edge of the sea. Our data suggest that the losses along the North

  6. Predicting severe winter coastal storm damage

    Energy Technology Data Exchange (ETDEWEB)

    Hondula, David M; Dolan, Robert, E-mail: hondula@virginia.edu [Department of Environmental Sciences, University of Virginia, PO Box 400123, Charlottesville, VA 22903 (United States)

    2010-07-15

    Over the past 40 years residents of, and visitors to, the North Carolina coastal barrier islands have experienced the destructive forces of several 'named' extratropical storms. These storms have caused large-scale redistributions of sand and loss of coastal structures and infrastructure. While most of the population living on the islands are familiar with the wintertime storms, the damage and scars of the 'super northeasters'-such as the Ash Wednesday storm of 7 March 1962, and the Halloween storm of 1989-are slipping away from the public's memory. In this research we compared the damage zones of the 1962 Ash Wednesday storm, as depicted on aerial photographs taken after the storm, with photos taken of the same areas in 2003. With these high-resolution aerial photos we were able to estimate the extent of new development which has taken place along the Outer Banks of North Carolina since 1962. Three damage zones were defined that extend across the islands from the ocean landward on the 1962 aerial photos: (1) the zone of almost total destruction on the seaward edge of the islands where the storm waves break; (2) the zone immediately inland where moderate structural damage occurs during severe storms; and (3) the zone of flood damage at the landward margin of the storm surge and overwash. We considered the rate of coastal erosion, the rate of development, and increases in property values as factors which may contribute to changing the financial risk for coastal communities. In comparing the values of these four factors with the 1962 damage data, we produced a predicted dollar value for storm damage should another storm of the magnitude of the 1962 Ash Wednesday storm occur in the present decade. This model also provides an opportunity to estimate the rate of increase in the potential losses through time as shoreline erosion continues to progressively reduce the buffer between the development and the edge of the sea. Our data suggest that the

  7. Predicting severe winter coastal storm damage

    Science.gov (United States)

    Hondula, David M.; Dolan, Robert

    2010-07-01

    Over the past 40 years residents of, and visitors to, the North Carolina coastal barrier islands have experienced the destructive forces of several 'named' extratropical storms. These storms have caused large-scale redistributions of sand and loss of coastal structures and infrastructure. While most of the population living on the islands are familiar with the wintertime storms, the damage and scars of the 'super northeasters'—such as the Ash Wednesday storm of 7 March 1962, and the Halloween storm of 1989—are slipping away from the public's memory. In this research we compared the damage zones of the 1962 Ash Wednesday storm, as depicted on aerial photographs taken after the storm, with photos taken of the same areas in 2003. With these high-resolution aerial photos we were able to estimate the extent of new development which has taken place along the Outer Banks of North Carolina since 1962. Three damage zones were defined that extend across the islands from the ocean landward on the 1962 aerial photos: (1) the zone of almost total destruction on the seaward edge of the islands where the storm waves break; (2) the zone immediately inland where moderate structural damage occurs during severe storms; and (3) the zone of flood damage at the landward margin of the storm surge and overwash. We considered the rate of coastal erosion, the rate of development, and increases in property values as factors which may contribute to changing the financial risk for coastal communities. In comparing the values of these four factors with the 1962 damage data, we produced a predicted dollar value for storm damage should another storm of the magnitude of the 1962 Ash Wednesday storm occur in the present decade. This model also provides an opportunity to estimate the rate of increase in the potential losses through time as shoreline erosion continues to progressively reduce the buffer between the development and the edge of the sea. Our data suggest that the losses along the

  8. Analysis of geomagnetically induced currents at a low-latitude region over the solar cycles 23 and 24: comparison between measurements and calculations

    Directory of Open Access Journals (Sweden)

    Barbosa Cleiton

    2015-01-01

    Full Text Available Geomagnetically Induced Currents (GIC are a space weather effect, which affects ground-based technological structures at all latitudes on the Earth’s surface. GIC occurrence and amplitudes have been monitored in power grids located at high and middle latitudes since 1970s and 1980s, respectively. This monitoring provides information about the GIC intensity and the frequency of occurrence during geomagnetic storms. In this paper, we investigate GIC occurrence in a power network at low latitudes (in the central Brazilian region during the solar cycles 23 and 24. Calculated and measured GIC data are compared for the most intense geomagnetic storms (i.e. −50 < Dst < −50 nT of the solar cycle 24. The results obtained from this comparison show a good agreement. The success of the model employed for the calculation of GIC leads to the possibility of determining GIC for events during the solar cycle 23 as well. Calculated GIC in one transformer reached ca. 30 A during the “Halloween storm” in 2003 whilst most frequent intensities lie below 10 A. The normalized inverse cumulative frequency for GIC data was calculated for the solar cycle 23 in order to perform a statistical analysis. It was found that a q-exponential Tsallis distribution fits the calculated GIC frequency distribution for more than 99% of the data. This analysis provides an overview of the long-term GIC monitoring at low latitudes and suggests new insight into critical phenomena involved in the GIC generation.

  9. Effect of hurricanes and violent storms on salt marsh

    Science.gov (United States)

    Leonardi, N.; Ganju, N. K.; Fagherazzi, S.

    2016-12-01

    Salt marsh losses have been documented worldwide because of land use change, wave erosion, and sea-level rise. It is still unclear how resistant salt marshes are to extreme storms and whether they can survive multiple events without collapsing. Based on a large dataset of salt marsh lateral erosion rates collected around the world, here, we determine the general response of salt marsh boundaries to wave action under normal and extreme weather conditions. As wave energy increases, salt marsh response to wind waves remains linear, and there is not a critical threshold in wave energy above which salt marsh erosion drastically accelerates. We apply our general formulation for salt marsh erosion to historical wave climates at eight salt marsh locations affected by hurricanes in the United States. Based on the analysis of two decades of data, we find that violent storms and hurricanes contribute less than 1% to long-term salt marsh erosion rates. In contrast, moderate storms with a return period of 2.5 mo are those causing the most salt marsh deterioration. Therefore, salt marshes seem more susceptible to variations in mean wave energy rather than changes in the extremes. The intrinsic resistance of salt marshes to violent storms and their predictable erosion rates during moderate events should be taken into account by coastal managers in restoration projects and risk management plans.

  10. The European storm Kyrill in January 2007: synoptic evolution, meteorological impacts and some considerations with respect to climate change

    Directory of Open Access Journals (Sweden)

    A. H. Fink

    2009-03-01

    Full Text Available The synoptic evolution and some meteorological impacts of the European winter storm Kyrill that swept across Western, Central, and Eastern Europe between 17 and 19 January 2007 are investigated. The intensity and large storm damage associated with Kyrill is explained based on synoptic and mesoscale environmental storm features, as well as on comparisons to previous storms. Kyrill appeared on weather maps over the US state of Arkansas about four days before it hit Europe. It underwent an explosive intensification over the Western North Atlantic Ocean while crossing a very intense zonal polar jet stream. A superposition of several favourable meteorological conditions west of the British Isles caused a further deepening of the storm when it started to affect Western Europe. Evidence is provided that a favourable alignment of three polar jet streaks and a dry air intrusion over the occlusion and cold fronts were causal factors in maintaining Kyrill's low pressure very far into Eastern Europe.

    Kyrill, like many other strong European winter storms, was embedded in a pre-existing, anomalously wide, north-south mean sea-level pressure (MSLP gradient field. In addition to the range of gusts that might be expected from the synoptic-scale pressure field, mesoscale features associated with convective overturning at the cold front are suggested as the likely causes for the extremely damaging peak gusts observed at many lowland stations during the passage of Kyrill's cold front. Compared to other storms, Kyrill was by far not the most intense system in terms of core pressure and circulation anomaly. However, the system moved into a pre-existing strong MSLP gradient located over Central Europe which extended into Eastern Europe. This fact is considered determinant for the anomalously large area affected by Kyrill.

    Additionally, considerations of windiness in climate change simulations using two state-of-the-art regional climate

  11. Rhode Island hurricanes and tropical storms: A fifty-six year summary 1936-1991. Technical memo

    International Nuclear Information System (INIS)

    Vallee, D.R.

    1993-03-01

    The paper was compiled to provide a general overview of all tropical cyclone activity near Rhode Island since 1936. The year of 1936 is arbitrary, chosen mainly to include a 'not so well known' system prior to the well documented Great New England Hurricane of 1938. Thirty-one such storms have affected the state in the past 56 years, either making landfall along the coast of southern New England, or passing close enough over the offshore waters to spread tropical storm or hurricane force conditions into the area. The intensities of these systems have ranged from weak, disorganized tropical storms to full fledged major hurricanes. The one feature common to almost all of the storms was a rapid acceleration toward Rhode Island, which greatly reduced the time to prepare and evacuate

  12. Meteorology, Macrophysics, Microphysics, Microwaves, and Mesoscale Modeling of Mediterranean Mountain Storms: The M8 Laboratory

    Science.gov (United States)

    Starr, David O. (Technical Monitor); Smith, Eric A.

    2002-01-01

    Comprehensive understanding of the microphysical nature of Mediterranean storms can be accomplished by a combination of in situ meteorological data analysis and radar-passive microwave data analysis, effectively integrated with numerical modeling studies at various scales, from synoptic scale down through the mesoscale, the cloud macrophysical scale, and ultimately the cloud microphysical scale. The microphysical properties of and their controls on severe storms are intrinsically related to meteorological processes under which storms have evolved, processes which eventually select and control the dominant microphysical properties themselves. This involves intense convective development, stratiform decay, orographic lifting, and sloped frontal lifting processes, as well as the associated vertical motions and thermodynamical instabilities governing physical processes that affect details of the size distributions and fall rates of the various types of hydrometeors found within the storm environment. Insofar as hazardous Mediterranean storms, highlighted in this study by three mountain storms producing damaging floods in northern Italy between 1992 and 2000, developing a comprehensive microphysical interpretation requires an understanding of the multiple phases of storm evolution and the heterogeneous nature of precipitation fields within a storm domain. This involves convective development, stratiform transition and decay, orographic lifting, and sloped frontal lifting processes. This also involves vertical motions and thermodynamical instabilities governing physical processes that determine details of the liquid/ice water contents, size disi:ributions, and fall rates of the various modes of hydrometeors found within hazardous storm environments.

  13. Modeling the ionosphere-thermosphere response to a geomagnetic storm using physics-based magnetospheric energy input: OpenGGCM-CTIM results

    Directory of Open Access Journals (Sweden)

    Connor Hyunju Kim

    2016-01-01

    Full Text Available The magnetosphere is a major source of energy for the Earth’s ionosphere and thermosphere (IT system. Current IT models drive the upper atmosphere using empirically calculated magnetospheric energy input. Thus, they do not sufficiently capture the storm-time dynamics, particularly at high latitudes. To improve the prediction capability of IT models, a physics-based magnetospheric input is necessary. Here, we use the Open Global General Circulation Model (OpenGGCM coupled with the Coupled Thermosphere Ionosphere Model (CTIM. OpenGGCM calculates a three-dimensional global magnetosphere and a two-dimensional high-latitude ionosphere by solving resistive magnetohydrodynamic (MHD equations with solar wind input. CTIM calculates a global thermosphere and a high-latitude ionosphere in three dimensions using realistic magnetospheric inputs from the OpenGGCM. We investigate whether the coupled model improves the storm-time IT responses by simulating a geomagnetic storm that is preceded by a strong solar wind pressure front on August 24, 2005. We compare the OpenGGCM-CTIM results with low-earth-orbit satellite observations and with the model results of Coupled Thermosphere-Ionosphere-Plasmasphere electrodynamics (CTIPe. CTIPe is an up-to-date version of CTIM that incorporates more IT dynamics such as a low-latitude ionosphere and a plasmasphere, but uses empirical magnetospheric input. OpenGGCM-CTIM reproduces localized neutral density peaks at ~ 400 km altitude in the high-latitude dayside regions in agreement with in situ observations during the pressure shock and the early phase of the storm. Although CTIPe is in some sense a much superior model than CTIM, it misses these localized enhancements. Unlike the CTIPe empirical input models, OpenGGCM-CTIM more faithfully produces localized increases of both auroral precipitation and ionospheric electric fields near the high-latitude dayside region after the pressure shock and after the storm onset

  14. Climate change implications and use of early warning systems for global dust storms

    Science.gov (United States)

    Harriman, Lindsey M.

    2014-01-01

    With increased changes in land cover and global climate, early detection and warning of dust storms in conjunction with effective and widespread information broadcasts will be essential to the prevention and mitigation of future risks and impacts. Human activities, seasonal variations and long-term climatic patterns influence dust storms. More research is needed to analyse these factors of dust mobilisation to create more certainty for the fate of vulnerable populations and ecosystems in the future. Early warning and communication systems, when in place and effectively implemented, can offer some relief to these vulnerable areas. As an issue that affects many regions of the world, there is a profound need to understand the potential changes and ultimately create better early warning systems for dust storms.

  15. Thyroid storm: an updated review.

    Science.gov (United States)

    Chiha, Maguy; Samarasinghe, Shanika; Kabaker, Adam S

    2015-03-01

    Thyroid storm, an endocrine emergency first described in 1926, remains a diagnostic and therapeutic challenge. No laboratory abnormalities are specific to thyroid storm, and the available scoring system is based on the clinical criteria. The exact mechanisms underlying the development of thyroid storm from uncomplicated hyperthyroidism are not well understood. A heightened response to thyroid hormone is often incriminated along with increased or abrupt availability of free hormones. Patients exhibit exaggerated signs and symptoms of hyperthyroidism and varying degrees of organ decompensation. Treatment should be initiated promptly targeting all steps of thyroid hormone formation, release, and action. Patients who fail medical therapy should be treated with therapeutic plasma exchange or thyroidectomy. The mortality of thyroid storm is currently reported at 10%. Patients who have survived thyroid storm should receive definite therapy for their underlying hyperthyroidism to avoid any recurrence of this potentially fatal condition. © The Author(s) 2013.

  16. The electric storm of November 1882

    Science.gov (United States)

    Love, Jeffrey J.

    2018-01-01

    In November 1882, an intense magnetic storm related to a large sunspot group caused widespread interference to telegraph and telephone systems and provided spectacular and unusual auroral displays. The (ring current) storm time disturbance index for this storm reached maximum −Dst ≈ 386 nT, comparable to Halloween storm of 29–31 October 2003, but from 17 to 20 November the aa midlatitude geomagnetic disturbance index averaged 214.25 nT, the highest 4 day level of disturbance since the beginning of aa index in 1868. This storm contributed to scientists' understanding of the reality of solar‐terrestrial interaction. Past occurrences of magnetic storms, like that of November 1882, can inform modern evaluations of the deleterious effects that a magnetic superstorm might have on technological systems of importance to society.

  17. On the surface physics affecting solar oscillation frequencies

    DEFF Research Database (Denmark)

    Houdek, G.; Trampedach, R.; Aarslev, M. J.

    2017-01-01

    . In this Letter, we address the physical processes of turbulent convection that are predominantly responsible for the frequency differences between standard models and observations, also called 'surface effects'. We compare measured solar frequencies from the Michelson Doppler Imager instrument on the SOlar...... physics in our model computation, we are able to reproduce the observed solar frequencies to less than or similar to 3 mu Hz without the need of any additional ad hoc functional corrections....

  18. Properties and geoeffectiveness of magnetic clouds in the rising, maximum and early declining phases of solar cycle 23

    Directory of Open Access Journals (Sweden)

    K. E. J. Huttunen

    2005-02-01

    Full Text Available The magnetic structure and geomagnetic response of 73 magnetic clouds (MC observed by the WIND and ACE satellites in solar cycle 23 are examined. The results have been compared with the surveys from the previous solar cycles. The preselected candidate MC events were investigated using the minimum variance analysis to determine if they have a flux-rope structure and to obtain the estimation for the axial orientation (θC, φC. Depending on the calculated inclination relative to the ecliptic we divided MCs into "bipolar" (θC<45° and "unipolar" (θC>45°. The number of observed MCs was largest in the early rising phase, although the halo CME rate was still low. It is likely that near solar maximum we did not identify all MCs at 1AU, as they were crossed far from the axis or they had interacted strongly with the ambient solar wind or with other CMEs. The occurrence rate of MCs at 1AU is also modified by the migration of the filament sites on the Sun towards the poles near solar maximum and by the deflection of CMEs towards the equator due to the fast solar wind flow from large polar coronal holes near solar minimum. In the rising phase nearly all bipolar MCs were associated with the rotation of the magnetic field from the south at the leading edge to the north at the trailing edge. The results for solar cycles 21-22 showed that the direction of the magnetic field in the leading portion of the MC starts to reverse at solar maximum. At solar maximum and in the declining phase (2000-2003 we observed several MCs with the rotation from the north to the south. We observed unipolar (i.e. highly inclined MCs frequently during the whole investigated period. For solar cycles 21-22 the majority of MCs identified in the rising phase were bipolar while in the declining phase most MCs were unipolar. The geomagnetic response of a given MC depends greatly on its magnetic structure and the orientation of the sheath fields. For each event we distinguished the

  19. Swashed away? Storm impacts on sandy beach macrofaunal communities

    Science.gov (United States)

    Harris, Linda; Nel, Ronel; Smale, Malcolm; Schoeman, David

    2011-09-01

    Storms can have a large impact on sandy shores, with powerful waves eroding large volumes of sand off the beach. Resulting damage to the physical environment has been well-studied but the ecological implications of these natural phenomena are less known. Since climate change predictions suggest an increase in storminess in the near future, understanding these ecological implications is vital if sandy shores are to be proactively managed for resilience. Here, we report on an opportunistic experiment that tests the a priori expectation that storms impact beach macrofaunal communities by modifying natural patterns of beach morphodynamics. Two sites at Sardinia Bay, South Africa, were sampled for macrofauna and physical descriptors following standard sampling methods. This sampling took place five times at three- to four-month intervals between April 2008 and August 2009. The second and last sampling events were undertaken after unusually large storms, the first of which was sufficiently large to transform one site from a sandy beach into a mixed shore for the first time in living memory. A range of univariate (linear mixed-effects models) and multivariate (e.g. non-metric multidimensional scaling, PERMANOVA) methods were employed to describe trends in the time series, and to explore the likelihood of possible explanatory mechanisms. Macrofaunal communities at the dune-backed beach (Site 2) withstood the effects of the first storm but were altered significantly by the second storm. In contrast, macrofauna communities at Site 1, where the supralittoral had been anthropogenically modified so that exchange of sediments with the beach was limited, were strongly affected by the first storm and showed little recovery over the study period. In line with predictions from ecological theory, beach morphodynamics was found to be a strong driver of temporal patterns in the macrofaunal community structure, with the storm events also identified as a significant factor, likely

  20. Storm-driven Mixing and Potential Impact on the Arctic Ocean

    Science.gov (United States)

    Yang, Jiayan; Comiso, Josefino; Walsh, David; Krishfield, Richard; Honjo, Susumu; Koblinsky, Chester J. (Technical Monitor)

    2001-01-01

    Observations of the ocean, atmosphere, and ice made by Ice-Ocean Environmental Buoys (IOEBs) indicate that mixing events reaching the depth of the halocline have occurred in various regions in the Arctic Ocean. Our analysis suggests that these mixing events were mechanically forced by intense storms moving across the buoy sites. In this study, we analyzed these mixing events in the context of storm developments that occurred in the Beaufort Sea and in the general area just north of Fram Strait, two areas with quite different hydrographic structures. The Beaufort Sea is strongly influenced by inflow of Pacific water through Bering Strait, while the area north of Fram Strait is directly affected by the inflow of warm and salty North Atlantic water. Our analyses of the basin-wide evolution of the surface pressure and geostrophic wind fields indicate that the characteristics of the storms could be very different. The buoy-observed mixing occurred only in the spring and winter seasons when the stratification was relatively weak. This indicates the importance of stratification, although the mixing itself was mechanically driven. We also analyze the distribution of storms, both the long-term climatology as well as the patterns for each year in the last two decades. The frequency of storms is also shown to be correlated- (but not strongly) to Arctic Oscillation indices. This study indicates that the formation of new ice that leads to brine rejection is unlikely the mechanism that results in the type of mixing that could overturn the halocline. On the other hand, synoptic-scale storms can force mixing deep enough to the halocline and thermocline layer. Despite a very stable stratification associated with the Arctic halocline, the warm subsurface thermocline water is not always insulated from the mixed layer.

  1. A comparison of the ground magnetic responses during the 2013 and 2015 St. Patrick's Day geomagnetic storms

    DEFF Research Database (Denmark)

    Xu, Z.; Hartinger, M. D.; Clauer, Robert C.

    2017-01-01

    The magnetosphere-ionosphere system response to extreme solar wind driving conditions depends on both the driving conditions and ionospheric conductivity. Since extreme driving conditions are rare, there are few opportunities to control for one parameter or another. The 17 March 2013 and 17 March...... 2015 geomagnetic storms driven by coronal mass ejections (CME) provide one such opportunity. The two events occur during the same solar illumination conditions; in particular, both occur near equinox on the same day of the year leading to similar ionospheric conductivity profiles. Moreover, both CMEs...... systems. There are dramatic differences between the intensity, onset time and occurrence, duration, and spatial structure of the current systems in each case. For example, differing solar wind driving conditions lead to interhemispheric asymmetries in the high-latitude ground magnetic response during...

  2. Ice storm '98: The electricity industry's great challenge

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    The biggest and most costly natural disaster to hit Canada in over a century, the ice storms of 1998, that transformed Eastern Canada into a virtual glacier, was discussed. Trees, wires, poles, transmission towers, transformers succumbed to the immense weight of the ice, countless transmission and distribution lines were destroyed, leaving millions in the dark and cold, many for several weeks. The unprecedented show of solidarity within the electricity industry, as hundreds of crews from utilities across Canada and the U.S., the many thousands of private individuals and some 16,000 members of the Canadian Forces that came to the assistance of those in the affected areas, working 16-hour days, braving falling trees and sub-zero temperatures, was truly astonishing, and clearly the stuff of which legends are made. The storm has humbled Canadian public authorities and especially the Canadian electricity industry. Besides honoring those that weathered the storm, and paying tribute to the utilities and private companies that reached out to assist in the relief efforts, this review also discusses the need for government agencies and utility companies to review their emergency preparedness plans. The objective is to improve them by incorporating the most important lessons learned from this experience, in an effort to forestall their future recurrence. It is generally accepted that the Ice Storm of '98 was a unique natural disaster that no amount of planning could have foreseen, much less prevented. Nevertheless, by examining the lessons learned, it might be possible to reduce the severity should a similar disaster occur again

  3. "Storms of crustal stress" and AE earthquake precursors

    Directory of Open Access Journals (Sweden)

    G. P. Gregori

    2010-02-01

    Full Text Available Acoustic emission (AE displays violent paroxysms preceding strong earthquakes, observed within some large area (several hundred kilometres wide around the epicentre. We call them "storms of crustal stress" or, briefly "crustal storms". A few case histories are discussed, all dealing with the Italian peninsula, and with the different behaviour shown by the AE records in the Cephalonia island (Greece, which is characterized by a different tectonic setting.

    AE is an effective tool for diagnosing the state of some wide slab of the Earth's crust, and for monitoring its evolution, by means of AE of different frequencies. The same effect ought to be detected being time-delayed, when referring to progressively lower frequencies. This results to be an effective check for validating the physical interpretation.

    Unlike a seismic event, which involves a much limited focal volume and therefore affects a restricted area on the Earth's surface, a "crustal storm" typically involves some large slab of lithosphere and crust. In general, it cannot be easily reckoned to any specific seismic event. An earthquake responds to strictly local rheological features of the crust, which are eventually activated, and become crucial, on the occasion of a "crustal storm". A "crustal storm" lasts typically few years, eventually involving several destructive earthquakes that hit at different times, at different sites, within that given lithospheric slab.

    Concerning the case histories that are here discussed, the lithospheric slab is identified with the Italian peninsula. During 1996–1997 a "crustal storm" was on, maybe elapsing until 2002 (we lack information for the period 1998–2001. Then, a quiet period occurred from 2002 until 26 May 2008, when a new "crustal storm" started, and by the end of 2009 it is still on. During the 1996–1997 "storm" two strong earthquakes occurred (Potenza and

  4. Thermospheric dynamics during the March 22, 1979, magnetic storm 1. Model simulations

    International Nuclear Information System (INIS)

    Roble, R.G.; Forbes, J.M.; Marcos, F.A.

    1987-01-01

    The physical processes involved in the transfer of energy from the solar wind to the magnetosphere and its release associated with substorms on March 22, 1979, have been studied in detail by the Coordinated Data Analysis Workshop 6 (CDAW 6). The information derived from the CDAW 6 study, as well as other information obtained from magnetospheric modeling, is used to prescribe the time-dependent variations of the parameterizations for the auroral and magnetospheric convection models that are incorporated within the National Center for Atmospheric Research thermospheric general circulation model (TGCM). The period preceding the magnetic storm (March 21) was geomagnetically quiet, and the TGCM was run until a diurnally reproducible pattern was obtained. The time variations of auroral particle precipitation and enhanced magnetospheric convection on March 22 caused a considerable disturbance in the high-latitude circulation, temperature, and composition during the storm period that began at about 1055 UT. Large- and medium-scale disturbances were launched during the event that propagated to equatorial latitudes. The thermospheric response in the northern hemisphere was larger than that generated in the southern hemisphere, because the auroral oval and magnetospheric convection pattenr in the northern hemisphere were in sunlight during the storm period whereas they were in darkness in the southern hemisphere. The storm response was also different in the upper and the lower thermosphere. In the upper thermosphere the winds generally followed the two-cell pattern of magnetospheric convecton with a lag of only 1/2 to 1 hour. In the lower thermosphere there was a pronounced asymmetry between the circulation cells on the dawnside and on the duskside of the polar cap

  5. Hurricane & Tropical Storm Impacts over the South Florida Metropolitan Area: Mortality & Government

    Science.gov (United States)

    Colon Pagan, I. C.

    2007-12-01

    Since 1985, the South Florida Metropolitan area (SFMA), which covers the counties of Miami-Dade, Broward, and Palm Beach, has been directly affected by 9 tropical cyclones: four tropical storms and 5 hurricanes. This continuous hurricane and tropical storm activity has awakened the conscience of the communities, government, and private sector, about the social vulnerability, in terms of age, gender, ethnicity, and others. Several factors have also been significant enough to affect the vulnerability of the South Florida Metropolitan area, like its geographic location which is at the western part of the Atlantic hurricane track, with a surface area of 6,137 square miles, and elevation of 15 feet. And second, from the 2006 Census estimate, this metropolitan area is the 7th most populous area in the United States supporting almost 1,571 individuals per square mile. Mortality levels due to hurricanes and tropical storms have fluctuated over the last 21 years without any signal of a complete reduction, a phenomenon that can be related to both physical characteristics of the storms and government actions. The average annual death count remains almost the same from 4.10 between 1985 and 1995 to 4 from 1996 to 2006. However, the probability of occurrence of a direct impact of an atmospheric disturbance has increase from 0.3 to 0.6, with an average of three hurricane or tropical storm direct impacts for every five. This analysis suggests an increasing problem with regard to atmospheric disturbances-related deaths in the South Florida Metropolitan area. In other words, despite substantial increases in population during the last 21 years, the number of tropical cyclone-related deaths is not declining; it's just being segregated among more storms. Gaps between each impact can be related to mortality levels. When that time increases in five years or more, such as Bob and Andrew or Irene and Katrina, or decreases in weeks or months, such as Harvey and Irene or Katrina and Wilma

  6. Coastal Storm Surge Analysis: Storm Surge Results. Report 5: Intermediate Submission No. 3

    Science.gov (United States)

    2013-11-01

    Vickery, P., D. Wadhera, A. Cox, V. Cardone , J. Hanson, and B. Blanton. 2012. Coastal storm surge analysis: Storm forcing (Intermediate Submission No...CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Jeffrey L. Hanson, Michael F. Forte, Brian Blanton

  7. Climatic Change and Dynamics of Northern Hemisphere Storm-tracks: Changes in Transient Eddies Behavior

    Science.gov (United States)

    Martynova, Yuliya; Krupchatnikov, Vladimir

    2013-04-01

    An evidence of our understanding of the general circulation is whether we can predict changes in the general circulation that might be associated with past or future climate changes. Changes in the location, intensity or seasonality of major climatological features of the general circulation could be more important than average temperature changes, particularly where these changes could affect local hydrology, energy balances, etc. Under these major climatological features we assume the poleward expansion of the tropical circulation (Hadley circulation), static stability (changes in the vertical temperature structure of the atmosphere), role of SST forcing, sea ice extension, extratropical eddies behavior. We have a question: would the climate change significantly affect the location and intensity of midlatitude storm-tracks and associated jets? Mean-flow interaction in midlatitudes produces low-frequency variations in the latitude of the jets. It is reasonable to think that a modest climate change might significantly affects the jets location and their associated storm tracks. The storm-tracks are defined as the region of strong baroclinicity (maximum meridional temperature gradient), which are determined on the basis of eddy statistics like eddy fluxes of angular momentum, energy, and water (with the use of high-bandpass filter). In the Northern Hemisphere, there are two major storms: in the region of Atlantic and Pacific. The storm-tracks play important role in the dynamics of weather and climate. They affect the global energy cycle and the hydrological cycle, and as a result they bring heavy rains and other hazardous weather phenomena in the middle latitudes. The recent increase in global tropopause heights is closely associated with systematic temperature changes below and above the tropopause. Temperature increases in the troposphere and decreases in the stratosphere. The pattern of warming and cooling also affects the zonal wind structure in the region of

  8. Unexpected storm-time nightside plasmaspheric density enhancement at low L shell

    Science.gov (United States)

    Chu, X.; Bortnik, J.; Denton, R. E.; Yue, C.

    2017-12-01

    We have developed a three-dimensional dynamic electron density (DEN3D) model in the inner magnetosphere using a neural network approach. The DEN3D model can provide spatiotemporal distribution of the electron density at any location and time that spacecraft observations are not available. Given DEN3D's good performance in predicting the structure and dynamic evolution of the plasma density, the salient features of the DEN3D model can be used to gain further insight into the physics. For instance, the DEN3D models can be used to find unusual phenomena that are difficult to detect in observations or simulations. We report, for the first time, an unexpected plasmaspheric density increase at low L shell regions on the nightside during the main phase of a moderate storm during 12-16 October 2004, as opposed to the expected density decrease due to storm-time plasmaspheric erosion. The unexpected density increase is first discovered in the modeled electron density distribution using the DEN3D model, and then validated using in-situ density measurements obtained from the IMAGE satellite. The density increase was likely caused by increased earthward transverse field plasma transport due to enhanced nightside ExB drift, which coincided with enhanced solar wind electric field and substorm activity. This is consistent with the results of physics-based simulation SAMI3 model which show earthward enhanced plasma transport and electron density increase at low L shells during storm main phase.

  9. Final Environmental Assessment Airfield Storm Drainage System Repair Joint Base Andrews-Naval Air Facility Washington, MD

    Science.gov (United States)

    2015-06-01

    the airfield. • Phase 1–September 2015 to October 2016: Replace or rehabilitate storm drain pipes between the West Runway and Taxiway Whiskey...activities, landfills , and other support and training operations have affected groundwater and surface waters at JBA with metals, volatile organic...the airfield.  Phase 1: September 2015 to October 2016: Replace or rehabilitate storm drain pipes between the West Runway and Taxiway Whiskey

  10. Relationships of storm-time changes in thermospheric mass density with solar wind/IMF parameters and ring current index of Sym-H

    Science.gov (United States)

    Zhou, Yunliang; Ma, S. Y.; Xiong, Chao; Luehr, Hermann

    The total air mass densities at about 500 km altitude are derived using super-STAR accelerom-eter measurements onboard GRACE satellites for 25 great magnetic storms with minimum Dst less than 100 nT during 2002 to 2006 years. Taking NRLMSISE-00 model-predicted densities without active ap index input as a reference baseline of quiet-time mass density, the storm-time changes in upper thermospheric mass densities are obtained by subtraction for all the storm events and sorted into different grids of latitude by local time sector. The relationships of the storm-time density changes with various interplanetary parameters and magnetospheric ring current index of Sym-H are statistically investigated. The parameters include Akasofu energy coupling function, the merging electric field Em, the magnitude of IMF component in the GSM y-z plane etc. as calculated from OMNI data at 1 AU. It is found that the storm-time changes in the upper thermospheric mass density have the best linear correlation with the Sym-H index in general, showing nearly zero time delay at low-latitudes and a little time ahead at high-latitudes for most cases. Unexpectedly, the magnitude of IMF component in the y-z plane, Byz, shows correlation with storm-time mass density changes better and closer than Akasofu function and even Em. And, the mass density changes lag behind Byz about 1-4 hours for most cases at low-latitudes. The correlations considered above are local time dependent, showing the lowest at dusk sectors. For the largest superstorm of November 2003, the changes in mass density are correlated very closely with Byz, Em, and Sym-H index, showing correlation coefficients averaged over all latitudes in noon sector as high as 0.93, 0.91 and 0.90 separately. The physical factors controlling the lag times between the mass density changes at mid-low-latitudes and the interplanetary parameter variations are also analyzed. The results in this study may pro-vide useful suggestions for establishing

  11. Assessing storm erosion hazards

    NARCIS (Netherlands)

    Ranasinghe, Ranasinghe W M R J B; Callaghan, D.; Ciavola, Paolo; Coco, Giovanni

    2017-01-01

    The storm erosion hazard on coasts is usually expressed as an erosion volume and/or associated episodic coastline retreat. The accurate assessment of present-day and future storm erosion volumes is a key task for coastal zone managers, planners and engineers. There are four main approaches that can

  12. Solar--geophysical data number 381. Part II. (Comprehensive reports). Data for November 1975-October 1975 and miscellanea. Explanation of data reports issued as number 378 (supplement) February 1976

    International Nuclear Information System (INIS)

    Leighton, H.I.

    1976-05-01

    This is part two (comprehensive reports) of a two part report on Solar--Geophysical Data. Included in this report are data for the months of October and November. The data recorded include solar flares, solar radio waves, energetic solar particles and plasma, and magnetograms of geomagnetic storms

  13. 46 CFR 169.329 - Storm rails.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Storm rails. 169.329 Section 169.329 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Construction and Arrangement Rails and Guards § 169.329 Storm rails. Suitable storm rails or hand grabs must be...

  14. 46 CFR 72.40-10 - Storm rails.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Storm rails. 72.40-10 Section 72.40-10 Shipping COAST... and Guards § 72.40-10 Storm rails. (a) Suitable storm rails shall be installed in all passageways and at the deckhouse sides where passengers or crew might have normal access. Storm rails shall be...

  15. Thyroid Storm Precipitated by Duodenal Ulcer Perforation

    Directory of Open Access Journals (Sweden)

    Shoko Natsuda

    2015-01-01

    Full Text Available Thyroid storm is a rare and life-threatening complication of thyrotoxicosis that requires prompt treatment. Thyroid storm is also known to be associated with precipitating events. The simultaneous treatment of thyroid storm and its precipitant, when they are recognized, in a patient is recommended; otherwise such disorders, including thyroid storm, can exacerbate each other. Here we report the case of a thyroid storm patient (a 55-year-old Japanese male complicated with a perforated duodenal ulcer. The patient was successfully treated with intensive treatment for thyroid storm and a prompt operation. Although it is believed that peptic ulcer rarely coexists with hyperthyroidism, among patients with thyroid storm, perforation of a peptic ulcer has been reported as one of the causes of fatal outcome. We determined that surgical intervention was required in this patient, reported despite ongoing severe thyrotoxicosis, and reported herein a successful outcome.

  16. Thyroid storm precipitated by duodenal ulcer perforation.

    Science.gov (United States)

    Natsuda, Shoko; Nakashima, Yomi; Horie, Ichiro; Ando, Takao; Kawakami, Atsushi

    2015-01-01

    Thyroid storm is a rare and life-threatening complication of thyrotoxicosis that requires prompt treatment. Thyroid storm is also known to be associated with precipitating events. The simultaneous treatment of thyroid storm and its precipitant, when they are recognized, in a patient is recommended; otherwise such disorders, including thyroid storm, can exacerbate each other. Here we report the case of a thyroid storm patient (a 55-year-old Japanese male) complicated with a perforated duodenal ulcer. The patient was successfully treated with intensive treatment for thyroid storm and a prompt operation. Although it is believed that peptic ulcer rarely coexists with hyperthyroidism, among patients with thyroid storm, perforation of a peptic ulcer has been reported as one of the causes of fatal outcome. We determined that surgical intervention was required in this patient, reported despite ongoing severe thyrotoxicosis, and reported herein a successful outcome.

  17. 46 CFR 116.920 - Storm rails.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Storm rails. 116.920 Section 116.920 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150... and Guards § 116.920 Storm rails. Suitable storm rails or hand grabs must be installed where necessary...

  18. 46 CFR 177.920 - Storm rails.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Storm rails. 177.920 Section 177.920 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) CONSTRUCTION AND ARRANGEMENT Rails and Guards § 177.920 Storm rails. Suitable storm rails or hand grabs must be...

  19. 46 CFR 127.320 - Storm rails.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Storm rails. 127.320 Section 127.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS CONSTRUCTION AND ARRANGEMENTS Rails and Guards § 127.320 Storm rails. Suitable storm rails must be installed in each passageway and at...

  20. Examine Precipitation Extremes in Terms of Storm Properties

    Science.gov (United States)

    Jiang, P.; Yu, Z.; Chen, L.; Gautam, M. R.; Acharya, K.

    2017-12-01

    The increasing potential of the extreme precipitation is of significant societal concern. Changes in precipitation extremes have been mostly examined using extreme precipitation indices or Intensity-Duration-Frequency (IDF) analyses, which often fail to reveal the characteristics of an integrated precipitation event. In this study, we will examine the precipitation extremes in terms of storm properties including storm duration, storm intensity, total storm precipitation, and within storm pattern. Single storm event will be identified and storm properties will be determined based on the hourly precipitation time series in the selected locations in southwest United States. Three types of extreme precipitation event will be recognized using the criteria as (1) longest storm duration; (2) Highest storm intensity; and (3) largest total precipitation over a storm. The trend and variation of extreme precipitation events will be discussed for each criterion. Based on the comparisons of the characteristics of extreme precipitation events identified using different criteria, we will provide guidelines for choosing proper criteria for extreme precipitation analysis in specific location.

  1. Effects of Solar Activity and Space Environment in 2003 Oct.

    Directory of Open Access Journals (Sweden)

    Kyung-Seok Cho

    2004-12-01

    Full Text Available In this paper, we present a good example of extreme solar and geomagnetic activities from October to November, 2003. These activities are characterized by very large sunspot groups, X-class solar flares, strong particle events, and huge geomagnetic storms. We discuss ground-based and space-based data in terms of space weather scales. Especially, we present several solar and geomagnetic disturbance data produced in Korea : sunspots, geo-magnetograms, aurora, Ionogram, and Total Electron Content (TEC map by GPS data. Finally, we introduce some examples of the satellite orbit and communication effects caused by these activities; e.g., the disturbances of the KOMPSAT-1 operational orbit and HF communication.

  2. Solar and Stellar Flares and Their Effects on Planets

    Science.gov (United States)

    Shibata, Kazunari

    2015-08-01

    Recent space observations of the Sun revealed that the solar atmosphere is full of explosions, such as flares and flare-like phenomena. These flares generate not only strong electromagnetic emissions but also nonthermal particles and bulk plasma ejections, which sometimes lead to geomagnetic storms and affect terrestrial environment and our civilization, damaging satellite, power-grids, radio communication etc. Solar flares are prototype of various explosions in our universe, and hence are important not only for geophysics and environmental science but also for astrophysics. The energy source of solar flares is now established to be magnetic energy stored near sunspots. There is now increasing observational evidence that solar flares are caused by magnetic reconnection, merging of anti-parallel magnetic field lines and associated magneto-plasma dynamics (Shibata and Magara 2011, Living Review). It has also been known that many stars show flares similar to solar flares, and often such stellar flares are much more energetic than solar flares. The total energy of a solar flare is typically 10^29 - 10^32 erg. On the other hand, there are much more energetic flares (10^33 - 10^38 erg) in stars, especially in young stars. These are called superflares. We argue that these superflares on stars can also be understood in a unified way based on the reconnection mechanism. Finally we show evidence of occurrence of superflares on Sun-like stars according to recent stellar observations (Maehara et al. 2012, Nature, Shibayama et al. 2013), which revealed that superflares with energy of 10^34 - 10^35 erg (100 - 1000 times of the largest solar flares) occur with frequency of once in 800 - 5000 years on Sun-like stars which are very similar to our Sun. Against the previous belief, these new observations as well as theory (Shibata et al. 2013) suggest that we cannot deny the possibility of superflares on the present Sun. Finally, we shall discuss possible impacts of these superflares

  3. Eurasian Winter Storm Activity at the End of the Century: A CMIP5 Multi-model Ensemble Projection

    Science.gov (United States)

    Basu, Soumik; Zhang, Xiangdong; Wang, Zhaomin

    2018-01-01

    Extratropical cyclone activity over Eurasia has exhibited a weakening trend in the recent decade. Extratropical cyclones bring precipitation and hence supply fresh water for winter crops in the mid- and high-latitude regions of Eurasia. Any changes in extratropical cyclone activity over Eurasia in the future may have a critical impact on winter agriculture and the economies of affected communities. However, potential future changes in regional storm activity over Eurasia have not been studied in detail. Therefore, in this study, we investigate anticipated changes in extratropical storm activity by the end of the century through a detailed examination of the historical and future emission scenarios from six different models from CMIP5. A statistical analysis of different parameters of storm activity using a storm identification and tracking algorithm reveals a decrease in the number of storms over mid-latitude regions. However, intense storms with longer duration are projected over high latitude Eurasia. A further examination of the physical mechanism for these changes reveals that a decrease in the meridional temperature gradient and a weakening of the vertical wind shear over the mid-latitudes are responsible for these changes in storm activity.

  4. 46 CFR 108.221 - Storm rails.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Storm rails. 108.221 Section 108.221 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction and Arrangement Rails § 108.221 Storm rails. Each unit must have a storm rail in the following...

  5. Er Storm P. en hardcore vagabond?

    DEFF Research Database (Denmark)

    Sortkær, Allan

    2002-01-01

    Den vagabond, som vi kender som Storm P.s, er ikke en figur, der kom fra en guddommelig inspiration eller deslige. Den var en allerede velkendt figur, før Storm P. tog den til sig, og figuren gennemgik radikale forandringer gennem Storm P.s liv: Krads social satire, hypervoldelig eller hyggelig...

  6. Multifluid Block-Adaptive-Tree Solar Wind Roe-Type Upwind Scheme: Magnetospheric Composition and Dynamics During Geomagnetic Storms-Initial Results

    Science.gov (United States)

    Glocer, A.; Toth, G.; Ma, Y.; Gombosi, T.; Zhang, J.-C.; Kistler, L. M.

    2009-01-01

    The magnetosphere contains a significant amount of ionospheric O+, particularly during geomagnetically active times. The presence of ionospheric plasma in the magnetosphere has a notable impact on magnetospheric composition and processes. We present a new multifluid MHD version of the Block-Adaptive-Tree Solar wind Roe-type Upwind Scheme model of the magnetosphere to track the fate and consequences of ionospheric outflow. The multifluid MHD equations are presented as are the novel techniques for overcoming the formidable challenges associated with solving them. Our new model is then applied to the May 4, 1998 and March 31, 2001 geomagnetic storms. The results are juxtaposed with traditional single-fluid MHD and multispecies MHD simulations from a previous study, thereby allowing us to assess the benefits of using a more complex model with additional physics. We find that our multifluid MHD model (with outflow) gives comparable results to the multispecies MHD model (with outflow), including a more strongly negative Dst, reduced CPCP, and a drastically improved magnetic field at geosynchronous orbit, as compared to single-fluid MHD with no outflow. Significant differences in composition and magnetic field are found between the multispecies and multifluid approach further away from the Earth. We further demonstrate the ability to explore pressure and bulk velocity differences between H+ and O+, which is not possible when utilizing the other techniques considered

  7. Environment, behavior and physiology: do birds use barometric pressure to predict storms?

    Science.gov (United States)

    Breuner, Creagh W; Sprague, Rachel S; Patterson, Stephen H; Woods, H Arthur

    2013-06-01

    Severe storms can pose a grave challenge to the temperature and energy homeostasis of small endothermic vertebrates. Storms are accompanied by lower temperatures and wind, increasing metabolic expenditure, and can inhibit foraging, thereby limiting energy intake. To avoid these potential problems, most endotherms have mechanisms for offsetting the energetic risks posed by storms. One possibility is to use cues to predict oncoming storms and to alter physiology and behavior in ways that make survival more likely. Barometric pressure declines predictably before inclement weather, and several lines of evidence indicate that animals alter behavior based on changes in ambient pressure. Here we examined the effects of declining barometric pressure on physiology and behavior in the white-crowned sparrow, Zonotrichia leucophrys. Using field data from a long-term study, we first evaluated the relationship between barometric pressure, storms and stress physiology in free-living white-crowned sparrows. We then manipulated barometric pressure experimentally in the laboratory and determined how it affects activity, food intake, metabolic rates and stress physiology. The field data showed declining barometric pressure in the 12-24 h preceding snowstorms, but we found no relationship between barometric pressure and stress physiology. The laboratory study showed that declining barometric pressure stimulated food intake, but had no effect on metabolic rate or stress physiology. These data suggest that white-crowned sparrows can sense and respond to declining barometric pressure, and we propose that such an ability may be common in wild vertebrates, especially small ones for whom individual storms can be life-threatening events.

  8. Electrical storm: clinical manifestations and management.

    Science.gov (United States)

    Littmann, L; Rennyson, S L

    2007-10-01

    Electrical storm is the clustering of hemodynamically destabilizing ventricular tachycardia or ventricular fibrillation that typically requires multiple electrical cardioversions or defibrillations within a 24-hour period. Electrical storm is frequently seen in the acute phase of myocardial infarction, in patients with the genetic arrhythmia syndromes, and in patients with implanted cardioverters-defibrillators. The evaluation and management should focus on the immediate suppression of the arrhythmia, a search for possible reversible causes, and attempts to prevent recurrences. In this review we present the most common conditions associated with electrical storm, therapeutic options for suppression of electrical storm, and new investigational techniques emerging for the treatment of electrical storm in refractory cases. The management of this life threatening arrhythmia typically requires the coordinated efforts of emergency medicine, critical care, cardiology, cardiac electrophysiology, and pacemaker experts.

  9. Progress in the Study of Coastal Storm Deposits

    Science.gov (United States)

    Xiong, Haixian; Huang, Guangqing; Fu, Shuqing; Qian, Peng

    2018-05-01

    Numerous studies have been carried out to identify storm deposits and decipher storm-induced sedimentary processes in coastal and shallow-marine areas. This study aims to provide an in-depth review on the study of coastal storm deposits from the following five aspects. 1) The formation of storm deposits is a function of hydrodynamic and sedimentary processes under the constraints of local geological and ecological factors. Many questions remain to demonstrate the genetic links between storm-related processes and a variety of resulting deposits such as overwash deposits, underwater deposits and hummocky cross-stratification (HCS). Future research into the formation of storm deposits should combine flume experiments, field observations and numerical simulations, and make full use of sediment source tracing methods. 2) Recently there has been rapid growth in the number of studies utilizing sediment provenance analysis to investigate the source of storm deposits. The development of source tracing techniques, such as mineral composition, magnetic susceptibility, microfossil and geochemical property, has allowed for better understanding of the depositional processes and environmental changes associated with coastal storms. 3) The role of extreme storms in the sedimentation of low-lying coastal wetlands with diverse ecosystem services has also drawn a great deal of attention. Many investigations have attempted to quantify widespread land loss, vertical marsh sediment accumulation and wetland elevation change induced by major hurricanes. 4) Paleostorm reconstructions based on storm sedimentary proxies have shown many advantages over the instrumental records and historic documents as they allow for the reconstruction of storm activities on millennial or longer time scales. Storm deposits having been used to establish proxies mainly include beach ridges and shelly cheniers, coral reefs, estuary-deltaic storm sequences and overwash deposits. Particularly over the past few

  10. Ionospheric disturbances under low solar activity conditions

    Czech Academy of Sciences Publication Activity Database

    Burešová, Dalia; Laštovička, Jan; Hejda, Pavel; Bochníček, Josef

    2014-01-01

    Roč. 54, č. 2 (2014), s. 185-196 ISSN 0273-1177 R&D Projects: GA ČR(CZ) GAP209/11/1908 Institutional support: RVO:68378289 ; RVO:67985530 Keywords : ionosphere * solar minimum * magnetic storm s * ionospheric variability Subject RIV: DG - Athmosphere Sciences, Meteorology; DG - Athmosphere Sciences, Meteorology (GFU-E) Impact factor: 1.358, year: 2014 http://www.sciencedirect.com/science/article/pii/S027311771400221X

  11. Response of the middle atmosphere to the geomagnetic storm of November 2004

    Science.gov (United States)

    Hocke, Klemens

    2017-02-01

    Ozone and temperature profiles of the satellite microwave limb sounder Aura/MLS are used for the derivation of the middle atmospheric response to the geomagnetic superstorm of 9 November 2004. We find a destruction of the tertiary ozone layer at 0.022 hPa (77 km) in the northern winter hemisphere lasting for about one week. This effect is surely due to the solar proton event (SPE) of November 2004. At the same time, the zonal mean temperature is enhanced by 5-10 K in the northern polar mesosphere. On the other hand, the zonal mean temperature is decreased by 5-10 K in the northern polar stratosphere. We do not think that the strong temperature perturbations are directly related to the SPE. It seems that the polar vortex was moved by the geomagnetic storm, and this vortex movement caused the strong temperature variations in the zonal mean. However, internal variability of temperature in the polar middle atmosphere in winter without any significant link to the geomagnetic storm cannot be excluded.

  12. Atmosphere surface storm track response to resolved ocean mesoscale in two sets of global climate model experiments

    Science.gov (United States)

    Small, R. Justin; Msadek, Rym; Kwon, Young-Oh; Booth, James F.; Zarzycki, Colin

    2018-05-01

    It has been hypothesized that the ocean mesoscale (particularly ocean fronts) can affect the strength and location of the overlying extratropical atmospheric storm track. In this paper, we examine whether resolving ocean fronts in global climate models indeed leads to significant improvement in the simulated storm track, defined using low level meridional wind. Two main sets of experiments are used: (i) global climate model Community Earth System Model version 1 with non-eddy-resolving standard resolution or with ocean eddy-resolving resolution, and (ii) the same but with the GFDL Climate Model version 2. In case (i), it is found that higher ocean resolution leads to a reduction of a very warm sea surface temperature (SST) bias at the east coasts of the U.S. and Japan seen in standard resolution models. This in turn leads to a reduction of storm track strength near the coastlines, by up to 20%, and a better location of the storm track maxima, over the western boundary currents as observed. In case (ii), the change in absolute SST bias in these regions is less notable, and there are modest (10% or less) increases in surface storm track, and smaller changes in the free troposphere. In contrast, in the southern Indian Ocean, case (ii) shows most sensitivity to ocean resolution, and this coincides with a larger change in mean SST as ocean resolution is changed. Where the ocean resolution does make a difference, it consistently brings the storm track closer in appearance to that seen in ERA-Interim Reanalysis data. Overall, for the range of ocean model resolutions used here (1° versus 0.1°) we find that the differences in SST gradient have a small effect on the storm track strength whilst changes in absolute SST between experiments can have a larger effect. The latter affects the land-sea contrast, air-sea stability, surface latent heat flux, and the boundary layer baroclinicity in such a way as to reduce storm track activity adjacent to the western boundary in the N

  13. Solar flares associated coronal mass ejection accompanied with DH type II radio burst in relation with interplanetary magnetic field, geomagnetic storms and cosmic ray intensity

    Science.gov (United States)

    Chandra, Harish; Bhatt, Beena

    2018-04-01

    In this paper, we have selected 114 flare-CME events accompanied with Deca-hectometric (DH) type II radio burst chosen from 1996 to 2008 (i.e., solar cycle 23). Statistical analyses are performed to examine the relationship of flare-CME events accompanied with DH type II radio burst with Interplanetary Magnetic field (IMF), Geomagnetic storms (GSs) and Cosmic Ray Intensity (CRI). The collected sample events are divided into two groups. In the first group, we considered 43 events which lie under the CME span and the second group consists of 71 events which are outside the CME span. Our analysis indicates that flare-CME accompanied with DH type II radio burst is inconsistent with CSHKP flare-CME model. We apply the Chree analysis by the superposed epoch method to both set of data to find the geo-effectiveness. We observed different fluctuations in IMF for arising and decay phase of solar cycle in both the cases. Maximum decrease in Dst during arising and decay phase of solar cycle is different for both the cases. It is noted that when flare lie outside the CME span CRI shows comparatively more variation than the flare lie under the CME span. Furthermore, we found that flare lying under the CME span is more geo effective than the flare outside of CME span. We noticed that the time leg between IMF Peak value and GSs, IMF and CRI is on average one day for both the cases. Also, the time leg between CRI and GSs is on average 0 to 1 day for both the cases. In case flare lie under the CME span we observed high correlation (0.64) between CRI and Dst whereas when flare lie outside the CME span a weak correlation (0.47) exists. Thus, flare position with respect to CME span play a key role for geo-effectiveness of CME.

  14. Storm water permitting for oil and gas facilities

    International Nuclear Information System (INIS)

    de Blanc, P.C.

    1991-01-01

    After several false starts, the US Environmental Protection Agency (EPA) published new federal storm water regulations in the November 16, 1990 Federal Register. These regulations identify facilities which must apply for a storm water permit and detail permit application requirements. The regulations appear at 40 CFR 122 Subpart B and became effective December 17, 1990. An outline of these regulations and their applicability to oil and gas facilities is presented. They are: facilities which require a storm water permit; types of storm water permits; permit application deadlines; permit application forms; facilities with existing storm water permits; storm water permit application data requirements; storm water sampling and analysis requirements; and EPA contacts for additional information

  15. Evaluation of super intense geomagnetic storms and related structures of the interplanetary medium through the observation of cosmic rays of high energy surface; Analise de tempestades geomagneticas super intensas e de estruturas do meio interplanetario relacionadas, atraves da observacao de raios cosmicos de superficie de alta energia

    Energy Technology Data Exchange (ETDEWEB)

    Savian, Jairo Francisco; Schuch, Nelson J., E-mail: savian@lacesm.ufsm.br, E-mail: njschuch@lacesm.ufsm.br [Centro Regional Sul de Pesquisas Espaciais - CRSPE/INPE-MCT, Santa Maria, RS (Brazil); Silva, Marlos Rockenbach da; Lago, Alisson dal; Gonzalez, Walter Demetrio, E-mail: marlos@dge.inpe.br, E-mail: dallago@dge.inpe.br, E-mail: gonzalez@dge.inpe.br [Instituto Nacional de Pesquisas Espaciais - INPE-MCT, Sao Jose dos Campos, SP (Brazil); Munakata, Kazuoki [Physics Department, Shinshu University, Matsumoto (Japan)

    2005-04-15

    It is believed that the physical mechanism responsible for the transference of energy from the solar wind to the Earth magnetosphere is the reconnection between the interplanetary magnetic field and the terrestrial magnetic field (Tsurutani and Gonzalez, 1997). The necessary criterion for a intense geomagnetic storms to occur, Dst < -100nT, is the existence of a dawn-dusk interplanetary electric field larger than 5 mV/m, for a period larger than 3 hours. Cosmic rays have been studied as a natural phenomenon that can tell much about both Earth's environment in space and distant astrophysical processes (Jokipii, 2000). A solar disturbance propagating away from the Sun affects the pre-existing population of galactic cosmic rays in a number of ways. The most famous one is known as the 'Forbush decrease', which is a suppression of ground cosmic-ray counts observed during geomagnetic disturbances. The objective of this work is to study the response of the Southern Space Observatory ground Muon Telescope observations, installed in Sao Martinho da Serra, RS, Brazil, to 3 super intense geomagnetic storms, combining observation provided by L1 satellites and ground detectors. (author)

  16. History and Development of Coronal Mass Ejections as a Key Player in Solar Terrestrial Relationship

    Science.gov (United States)

    Gopalswamy, N.

    2016-01-01

    Coronal mass ejections (CMEs) are relatively a recently discovered phenomenon in 1971, some 15 years into the Space Era. It took another two decades to realize that CMEs are the most important players in solar terrestrial relationship as the root cause of severe weather in Earths space environment. CMEs are now counted among the major natural hazards because they cause large solar energetic particle (SEP) events and major geomagnetic storms, both of which pose danger to humans and their technology in space and ground. Geomagnetic storms discovered in the 1700s, solar flares discovered in the 1800s, and SEP events discovered in the 1900s are all now found to be closely related to CMEs via various physical processes occurring at various locations in and around CMEs, when they interact with the ambient medium. This article identifies a number of key developments that preceded the discovery of white-light CMEs suggesting that CMEs were waiting to be discovered. The last two decades witnessed an explosion of CME research following the launch of the Solar and Heliospheric Observatory mission in 1995, resulting in the establishment of a full picture of CMEs.

  17. No Calm After the Storm: A Systematic Review of Human Health Following Flood and Storm Disasters.

    Science.gov (United States)

    Saulnier, Dell D; Brolin Ribacke, Kim; von Schreeb, Johan

    2017-10-01

    Introduction How the burden of disease varies during different phases after floods and after storms is essential in order to guide a medical response, but it has not been well-described. The objective of this review was to elucidate the health problems following flood and storm disasters. A literature search of the databases Medline (US National Library of Medicine, National Institutes of Health; Bethesda, Maryland USA); Cinahl (EBSCO Information Services; Ipswich, Massachusetts USA); Global Health (EBSCO Information Services; Ipswich, Massachusetts USA); Web of Science Core Collection (Thomson Reuters; New York, New York USA); Embase (Elsevier; Amsterdam, Netherlands); and PubMed (National Center for Biotechnology Information, National Institutes of Health; Bethesda, Maryland USA) was conducted in June 2015 for English-language research articles on morbidity or mortality and flood or storm disasters. Articles on mental health, interventions, and rescue or health care workers were excluded. Data were extracted from articles that met the eligibility criteria and analyzed by narrative synthesis. The review included 113 studies. Poisonings, wounds, gastrointestinal infections, and skin or soft tissue infections all increased after storms. Gastrointestinal infections were more frequent after floods. Leptospirosis and diabetes-related complications increased after both. The majority of changes occurred within four weeks of floods or storms. Health changes differently after floods and after storms. There is a lack of data on the health effects of floods alone, long-term changes in health, and the strength of the association between disasters and health problems. This review highlights areas of consideration for medical response and the need for high-quality, systematic research in this area. Saulnier DD , Brolin Ribacke K , von Schreeb J . No calm after the storm: a systematic review of human health following flood and storm disasters. Prehosp Disaster Med. 2017;32(5):568-579.

  18. Evidence for Gravity Wave Seeding of Convective Ionosphere Storms Initiated by Deep Troposphere Convection

    Science.gov (United States)

    Kelley, M. C.; Pfaff, R. F., Jr.; Dao, E. V.; Holzworth, R. H., II

    2014-12-01

    With the increase in solar activity, the Communications/Outage Forecast System satellite (C/NOFS) now goes below the F peak. As such, we now can study the development of Convective Ionospheric Storms (CIS) and, most importantly, large-scale seeding of the low growth-rate Rayleigh-Taylor (R-T) instability. Two mechanisms have been suggested for such seeding: the Collisional Kelvin-Helmholtz Instability (CKHI) and internal atmospheric gravity waves. A number of observations have shown that the spectrum of fully developed topside structures peaks at 600 km and extends to over 1000 km. These structures are exceedingly difficult to explain by CKHI. Here we show that sinusoidal plasma oscillations on the bottomside during daytime develop classical R-T structures on the nightside with the background 600 km structure still apparent. In two case studies, thunderstorm activity was observed east of the sinusoidal features in the two hours preceding the C/NOFS passes. Thus, we argue that convective tropospheric storms are a likely source of these sinusoidal features.

  19. GPS phase scintillation at high latitudes during the geomagnetic storm of 17-18 March 2015

    DEFF Research Database (Denmark)

    Prikryl, P.; Ghoddousi-Fard, R.; Weygand, J. M.

    2016-01-01

    The geomagnetic storm of 17–18 March 2015 was caused by the impacts of a coronal mass ejection and a high-speed plasma stream from a coronal hole. The high-latitude ionosphere dynamics is studied using arrays of ground-based instruments including GPS receivers, HF radars, ionosondes, riometers......, and magnetometers. The phase scintillation index is computed for signals sampled at a rate of up to 100 Hz by specialized GPS scintillation receivers supplemented by the phase scintillation proxy index obtained from geodetic-quality GPS data sampled at 1 Hz. In the context of solar wind coupling...... to the magnetosphere-ionosphere system, it is shown that GPS phase scintillation is primarily enhanced in the cusp, the tongue of ionization that is broken into patches drawn into the polar cap from the dayside storm-enhanced plasma density, and in the auroral oval. In this paper we examine the relation between...

  20. Intensity of the Fe XV emission line corona, the level of geomagnetic activity and the velocity of the solar wind

    International Nuclear Information System (INIS)

    Bell, B.; Noci, G.

    1976-01-01

    The average solar wind velocity and the level of geomagnetic activity (Kp) following central meridian passage of coronal weak and bright features identified from Oso 7 isophotograms of Fe XV (284 A) are determined by the method of superposed epochs. Results are consistent with the concept that bright regions possess magnetic field of closed configurations, thereby reducing particle escape, while coronal holes possess open magnetic field lines favorable to particle escape or enhanced outflow of the solar wind. Coronal holes are identified with Bartels' M regions not only statistically but by linking specific long-lived holes with individual sequences of geomagnetic storms. In the study of bright region a subdivision by brightness temperature (T/sub b/) of associated 9.1-cm radiation was found to be significant, with the region s of higher T/sub b/ having a stronger inhibiting power on the outflow of the solar wind when they were located in the solar hemisphere on the same side of the solar equator as the earth. Regions of highest T/sub b/ most strongly depress the outflow of solar wind but are also the most likely to produce flare-associated great storms

  1. The StoRM Certification Process

    International Nuclear Information System (INIS)

    Ronchieri, Elisabetta; Dibenedetto, Michele; Zappi, Riccardo; Dal Pra, Stefano; Aiftimiei, Cristina; Traldi, Sergio

    2011-01-01

    StoRM is an implementation of the SRM interface version 2.2 used by all Large Hadron Collider (LHC) experiments and non-LHC experiments as SRM endpoint at different Tiers of Worldwide LHC Computing Grid. The complexity of its services and the demand of experiments and users are increasing day by day. The growing needs in terms of service level by the StoRM users communities make it necessary to design and implement a more effective testing procedure to quickly and reliably validate new StoRM candidate releases both in code side (for example via test units, and schema valuator) and in final product software (for example via functionality tests, and stress tests). Testing software service is a very critical quality activity performed in a very ad-hoc informal manner by developers, testers and users of StoRM up to now. In this paper, we describe the certification mechanism used by StoRM team to increase the robustness and reliability of the StoRM services. Various typologies of tests, such as quality, installation, configuration, functionality, stress and performance, defined on the base of a set of use cases gathered as consequence of the collaboration among the StoRM team, experiments and users, are illustrated. Each typology of test is either increased or decreased easily from time to time. The proposed mechanism is based on a new configurable testsuite. This is executed by the certification team, who is responsible for validating the release candidate package as well as bug fix (or patch) package, given a certain testbed that considers all possible use cases. In correspondence of each failure, the package is given back to developers waiting for validating a new package.

  2. The comparison of SRs' variation affected by solar events observed in America and in China

    Science.gov (United States)

    Yu, H.; Williams, E.

    2017-12-01

    Schumann Resonances(SRs) are the electromagnetic resonance wave propagating in the earth-ionosphere cavity. Its characteristic of propagation are modified by the variation of ionosphere. So SRs can be the tools of monitoring the ionosphere which is often perturbed by solar events, x-ray emission and some other space-weather events (Roldugin et.al., 2004, De et al., 2010; Satori et.al., 2015). In present work, the amplitude and intrinsic frequencies of SRs observed at RID station in America and YSH station in China are compared. The variation of SRs during the solar flare on Feb. 15, 2011 are analyzed. Two-Dimensional Telegraph Equation(TDTE) method is used to simulate the perturbation of ionosphere by solar proton events. From the simulation and observation, the asymmetric construction of ionoshphere which is perturbed by the solar event will affect the amplitudes and frequencies of SRs. Due to the interfere influence of forward and backward propagation of electromagnetic field, the SR amplitude on different station will present different variation. The distance among the lightning source, observer and perturbed area will produce the different variation of amplitude and frequency for different station' SR.

  3. Web site lets solar scientists inform and inspire students

    Science.gov (United States)

    Hauck, Karin

    2012-07-01

    Where on the Web can a middle school girl ask a female solar scientist about solar storms, the course and behavior of charged solar particles, and the origin of the Sun's dynamo—and also find out what the scientist was like as a child, whether the scientist has tattoos or enjoys snowboarding, what she likes and dislikes about her career, and how she balances her energy for work and family life? These kinds of exchanges happen at Solar Week (http://www.solarweek.org; see Figure 1). Established in 2000, Solar Week is an online resource for middle and lower high school students about the science of the Sun, sponsored by the Center for Science Education at the Space Sciences Laboratory (CSE@SSL) at the University of California, Berkeley (UC Berkeley). The Web site's goals are to educate students about the Sun and solar physics and to encourage future careers in science—especially for girls. One way is by giving solar scientists the chance to be relatable role models, to answer students' questions, and to share their experiences in an online forum.

  4. Factors Affecting The Use and Development of Solar Energy in Iran's Agricultural Sector

    Directory of Open Access Journals (Sweden)

    Mohsen Mohammadi

    2017-03-01

    Keywords: Agriculture, Renewable Energy, Fossil, Fuel, Sustainability Article History: Received Nov 16th 2016; Received in revised form January 12nd 2017; Accepted 3rd February 2017; Available online How to Cite This Article: Mohammadi, M and Yavari, G. (2017 Factors affecting the use and development of solar energy in Iran's agricultural sector. International Journal of Renewable Energy Development, 6(1,45-53. http://dx.doi.org/10.14710/ijred.6.1.45-53

  5. Radio Astronomers Get Their First Glimpse of Powerful Solar Storm

    Science.gov (United States)

    2001-08-01

    Astronomers have made the first radio-telescope images of a powerful coronal mass ejection on the Sun, giving them a long-sought glimpse of hitherto unseen aspects of these potentially dangerous events. "These observations are going to provide us with a new and unique tool for deciphering the mechanisms of coronal mass ejections and how they are related to other solar events," said Tim Bastian, an astronomer at the National Science Foundation's National Radio Astronomy Observatory (NRAO) in Charlottesville, Virginia. Radio image of coronal mass ejection; circle indicates the size and location of the Sun. White dots are where radio spectral measurements were made. Bastian, along with Monique Pick, Alain Kerdraon and Dalmiro Maia of the Paris Observatory, and Angelos Vourlidas of the Naval Research Laboratory in Washington, D.C., used a solar radio telescope in Nancay, France, to study a coronal mass ejection that occurred on April 20, 1998. Their results will be published in the September 1 edition of the Astrophysical Journal Letters. Coronal mass ejections are powerful magnetic explosions in the Sun's corona, or outer atmosphere, that can blast billions of tons of charged particles into interplanetary space at tremendous speeds. If the ejection is aimed in the direction of Earth, the speeding particles interact with our planet's magnetic field to cause auroral displays, radio-communication blackouts, and potentially damage satellites and electric-power systems. "Coronal mass ejections have been observed for many years, but only with visible-light telescopes, usually in space. While previous radio observations have provided us with powerful diagnostics of mass ejections and associated phenomena in the corona, this is the first time that one has been directly imaged in wavelengths other than visible light," Bastian said. "These new data from the radio observations give us important clues about how these very energetic events work," he added. The radio images show an

  6. Does solar activity affect human happiness?

    Science.gov (United States)

    Kristoufek, Ladislav

    2018-03-01

    We investigate the direct influence of solar activity (represented by sunspot numbers) on human happiness (represented by the Twitter-based Happiness Index). We construct four models controlling for various statistical and dynamic effects of the analyzed series. The final model gives promising results. First, there is a statistically significant negative influence of solar activity on happiness which holds even after controlling for the other factors. Second, the final model, which is still rather simple, explains around 75% of variance of the Happiness Index. Third, our control variables contribute significantly as well: happiness is higher in no sunspots days, happiness is strongly persistent, there are strong intra-week cycles and happiness peaks during holidays. Our results strongly contribute to the topical literature and they provide evidence of unique utility of the online data.

  7. A Carrington-like geomagnetic storm observed in the 21st century

    Directory of Open Access Journals (Sweden)

    Cid Consuelo

    2015-01-01

    Full Text Available In September 1859 the Colaba observatory measured the most extreme geomagnetic disturbance ever recorded at low latitudes related to solar activity: the Carrington storm. This paper describes a geomagnetic disturbance case with a profile extraordinarily similar to the disturbance of the Carrington event at Colaba: the event on 29 October 2003 at Tihany magnetic observatory in Hungary. The analysis of the H-field at different locations during the “Carrington-like” event leads to a re-interpretation of the 1859 event. The major conclusions of the paper are the following: (a the global Dst or SYM-H, as indices based on averaging, missed the largest geomagnetic disturbance in the 29 October 2003 event and might have missed the 1859 disturbance, since the large spike in the horizontal component (H of terrestrial magnetic field depends strongly on magnetic local time (MLT; (b the main cause of the large drop in H recorded at Colaba during the Carrington storm was not the ring current but field-aligned currents (FACs; and (c the very local signatures of the H-spike imply that a Carrington-like event can occur more often than expected.

  8. Mapping Hurricane Rita inland storm tide

    Science.gov (United States)

    Berenbrock, Charles; Mason, Jr., Robert R.; Blanchard, Stephen F.; Simonovic, Slobodan P.

    2009-01-01

    Flood-inundation data are most useful for decision makers when presented in the context of maps of effected communities and (or) areas. But because the data are scarce and rarely cover the full extent of the flooding, interpolation and extrapolation of the information are needed. Many geographic information systems (GIS) provide various interpolation tools, but these tools often ignore the effects of the topographic and hydraulic features that influence flooding. A barrier mapping method was developed to improve maps of storm tide produced by Hurricane Rita. Maps were developed for the maximum storm tide and at 3-hour intervals from midnight (0000 hour) through noon (1200 hour) on September 24, 2005. The improved maps depict storm-tide elevations and the extent of flooding. The extent of storm-tide inundation from the improved maximum storm-tide map was compared to the extent of flood-inundation from a map prepared by the Federal Emergency Management Agency (FEMA). The boundaries from these two maps generally compared quite well especially along the Calcasieu River. Also a cross-section profile that parallels the Louisiana coast was developed from the maximum storm-tide map and included FEMA high-water marks.

  9. The geomagnetic cutoff rigidities at high latitudes for different solar wind and geomagnetic conditions

    International Nuclear Information System (INIS)

    Chu, W.; Univ. of Chinese Academy of Sciences, Beijing; Qin, G.

    2016-01-01

    Studying the access of the cosmic rays (CRs) into the magnetosphere is important to understand the coupling between the magnetosphere and the solar wind. In this paper we numerically studied CRs' magnetospheric access with vertical geomagnetic cutoff rigidities using the method proposed by Smart and Shea (1999). By the study of CRs' vertical geomagnetic cutoff rigidities at high latitudes we obtain the CRs' window (CRW) whose boundary is determined when the vertical geomagnetic cutoff rigidities drop to a value lower than a threshold value. Furthermore, we studied the area of CRWs and found out they are sensitive to different parameters, such as the z component of interplanetary magnetic field (IMF), the solar wind dynamic pressure, AE index, and Dst index. It was found that both the AE index and Dst index have a strong correlation with the area of CRWs during strong geomagnetic storms. However, during the medium storms, only AE index has a strong correlation with the area of CRWs, while Dst index has a much weaker correlation with the area of CRWs. This result on the CRW can be used for forecasting the variation of the cosmic rays during the geomagnetic storms.

  10. Characteristics of solar and heliospheric ion populations observed near earth

    International Nuclear Information System (INIS)

    Gloeckler, G.

    1984-01-01

    The composition and spectra of ions in solar-energetic-particle and energetic-storm-particle events, of diffuse ions upstream of the earth bow shock, and of ions in deep-geomagnetic-tail plasmoids are characterized in a summary of in situ observations. Data are presented in graphs and tables, and remarkable similarities are noted in the distribution functions of the heliospheric ion populations. The solar wind, acting through acceleration mechanisms associated with shocks and turbulence, is identified as the major plasma source of suprathermal and energetic particles. 33 references

  11. Water quality during storm events from two constructed wetlands receiving mine drainage

    International Nuclear Information System (INIS)

    Stark, L.R.; Brooks, R.P.; Williams, F.M.; Stevens, S.E. Jr.; Davis, L.K.

    1994-01-01

    Flow rates, pH, iron concentration, and manganese concentration were measured during several storm event at two constructed wetlands receiving mine water. During a substantial rain event, flow rates at both the wetland outlets surpassed flow rates at the wetland inlets, reflecting incident rainfall and differences in wetland area at the two sites. A significant positive correlation existed between local rainfall and outflow rates at the larger wetland, but not between rainfall and inflow rates. During storm events, outlet pH, relative to inlet pH, was slightly elevated at the larger wetland, and depressed at the smaller wetland. However, over the course of one year, rainfall was uncorrelated to outlet pH in the larger wetland. A substantial rain event at the smaller wetland resulted in a temporary elevation in outlet iron concentrations, with treatment efficiency reduced to near zero. However, in the larger wetland, outlet iron concentrations were not significantly affected by storm events. 14 refs., 7 figs., 4 tabs

  12. Ionosphere dynamics over the Southern Hemisphere during the 31 March 2001 severe magnetic storm using multi-instrument measurement data

    Directory of Open Access Journals (Sweden)

    E. Yizengaw

    2005-03-01

    Full Text Available The effects of the 31 March 2001 severe magnetic storm on the Southern Hemisphere ionosphere have been studied using ground-based and satellite measurements. The prime goal of this comprehensive study is to track the ionospheric response from high-to-low latitude to obtain a clear understanding of storm-time ionospheric change. The study uses a combination of ionospheric Total Electron Content (TEC obtained from GPS signal group delay and phase advance measurements, ionosonde data, and data from satellite in-situ measurements, such as the Defense Metrological Satellite Program (DMSP, TOPographic EXplorer (TOPEX, and solar wind data from the Advanced Composition Explorer (ACE. A chain of Global Positioning System (GPS stations near the 150° E meridian has been used to give comprehensive latitude coverage extending from the cusp to the equatorial region. A tomographic inversion algorithm has been applied to the GPS TEC measurements to obtain maps of the latitudinal structure of the ionospheric during this severe magnetic storm period, enabling both the spatial and temporal response of the ionosphere to be studied. Analysis of data from several of the instruments indicates that a strong density enhancement occurred at mid-latitudes at 11:00 UT on 31 March 2001 and was followed by equatorward propagating large-scale Travelling Ionospheric Disturbances (TIDs. The tomographic reconstruction revealed important features in ionospheric structure, such as quasi-wave formations extending finger-like to higher altitudes. The most pronounced ionospheric effects of the storm occurred at high- and mid-latitudes, where strong positive disturbances occurred during the storm main phase, followed by a long lasting negative storm effect during the recovery phase. Relatively minor storm effects occurred in the equatorial region.

  13. The ionosphere of Europe and North America before the magnetic storm of October 28, 2003

    Science.gov (United States)

    Blagoveshchensky, D. V.; Macdugall, J. W.; Pyatkova, A. V.

    2006-05-01

    The X17 solar flare occurred on October 28, 2003, and was followed by the X10 flare on October 29. These flares caused very strong geomagnetic storms (Halloween storms). The aim of the present study is to compare the variations in two main ionospheric parameters ( foF2 and hmF2) at two chains of ionosondes located in Europe and North America for the period October 23-28, 2003. This interval began immediately before the storm of October 28 and includes its commencement. Another task of the work is to detect ionospheric precursors of the storm or substorm expansion phase. An analysis is based on SPIDR data. The main results are as follows. The positive peak of δ foF2 (where δ is the difference between disturbed and quiet values) is observed several hours before the magnetic storm or substorm commencement. This peak can serve as a disturbance precursor. The amplitude of δ foF2 values varies from 20 to 100% of the foF2 values. The elements of similarity in the variations in the δ foF2 values at two chains are as follows: (a) the above δ foF2 peak is as a rule observed simultaneously at two chains before the disturbance; (b) the δ foF2 variations are similar at all midlatitude (or, correspondingly, high-latitude) ionosondes of the chain. The differences in the δ foF2 values are as follows: (a) the effect of the main phase and the phase of strong storm recovery at one chain differs from such an effect at another chain; (b) the manifestation of disturbances at high-latitude stations of the chain differ from the manifestations at midlatitude stations. The δ hmF2 variations are approximately opposite to the δ foF2 variations, and the δ hmF2 values lie in the interval 15-25% of the hmF2 values. The performed study is useful and significant in studying the problems of the space weather, especially in a short-term prediction of ionospheric disturbances caused by magnetospheric storms or substorms.

  14. Advances in magnetospheric storm and substorm research: 1989-1991

    International Nuclear Information System (INIS)

    Fairfield, D.H.

    1992-01-01

    Geomagnetic storms represent the magnetospheric response to fast solar wind and unusually large southward interplanetary magnetic fields that are caused by solar processes and resulting dynamics in the interplanetary medium. The solar wind/magnetosphere interaction is, however, more commonly studied via smaller, more common, magnetospheric substorms. Accumulating evidence suggests that two separate magnetospheric current systems are important during magnetospheric substorms. Currents directly driven by the solar wind/magnetosphere interaction produce magnetic field variations that make important contributions to the AE index but have little relation to the many effects traditionally associated with sudden substorm onsets. Currents driven by energy unloaded from the magnetotail form the nightside current wedge and are associated with onset effects such as auroral breakup, field dipolarization, and particle acceleration. Observations are gradually leading to a coherent picture of the interrelations among these various onset phenomena, but their cause remains a controversial question. The abrupt nature of substorm onsets suggests a magnetospheric instability, but doubt remains as to its nature and place of origin. Measurements increasingly suggest the region of 7-10 R E near midnight as the likely point of origin, but it is not clear that the long-popular tearing mode can go unstable this close to the Earth, where it may be stabilized by a small northward field component. Also the tailward flows that would be expected tailward of a near-Earth neutral line are seldom seen inside of 19 R E . The changing magnetic field configuration during substorms means that existing static models cannot be used to map phenomena between the magnetosphere and the ground at these interesting times

  15. Identification of the different magnetic field contributions during a geomagnetic storm in magnetospheric and ground observations

    Directory of Open Access Journals (Sweden)

    T. Alberti

    2016-11-01

    Full Text Available We used the empirical mode decomposition (EMD to investigate the time variation of the magnetospheric and ground-based observations of the Earth's magnetic field during both quiet and disturbed periods. We found two timescale variations in magnetospheric data which are associated with different magnetospheric current systems and the characteristic diurnal orbital variation, respectively. On the ground we identified three timescale variations related to the solar-wind–magnetosphere high-frequency interactions, the ionospheric processes, and the internal dynamics of the magnetosphere. This approach is able to identify the different physical processes involved in solar-wind–magnetosphere–ionosphere coupling. In addition, the large-timescale contribution can be used as a local index for the identification of the intensity of a geomagnetic storm on the ground.

  16. Effect of solar wind plasma parameters on space weather

    International Nuclear Information System (INIS)

    Rathore, Balveer S.; Gupta, Dinesh C.; Kaushik, Subhash C.

    2015-01-01

    Today's challenge for space weather research is to quantitatively predict the dynamics of the magnetosphere from measured solar wind and interplanetary magnetic field (IMF) conditions. Correlative studies between geomagnetic storms (GMSs) and the various interplanetary (IP) field/plasma parameters have been performed to search for the causes of geomagnetic activity and develop models for predicting the occurrence of GMSs, which are important for space weather predictions. We find a possible relation between GMSs and solar wind and IMF parameters in three different situations and also derived the linear relation for all parameters in three situations. On the basis of the present statistical study, we develop an empirical model. With the help of this model, we can predict all categories of GMSs. This model is based on the following fact: the total IMF B total can be used to trigger an alarm for GMSs, when sudden changes in total magnetic field B total occur. This is the first alarm condition for a storm's arrival. It is observed in the present study that the southward B z component of the IMF is an important factor for describing GMSs. A result of the paper is that the magnitude of B z is maximum neither during the initial phase (at the instant of the IP shock) nor during the main phase (at the instant of Disturbance storm time (Dst) minimum). It is seen in this study that there is a time delay between the maximum value of southward B z and the Dst minimum, and this time delay can be used in the prediction of the intensity of a magnetic storm two-three hours before the main phase of a GMS. A linear relation has been derived between the maximum value of the southward component of B z and the Dst, which is Dst = (−0.06) + (7.65) B z +t. Some auxiliary conditions should be fulfilled with this, for example the speed of the solar wind should, on average, be 350 km s −1 to 750 km s −1 , plasma β should be low and, most importantly, plasma temperature

  17. Solar wind and its interaction with the Earth magnetosphere

    International Nuclear Information System (INIS)

    Grib, S.A.

    1978-01-01

    A critical review is given regarding the research of the stationary and non-stationary interaction of the solar wind with the Earth magnetosphere. Highlighted is the significance of the interplanetary magnetic field in the non-stationary movement of the solar wind flux. The problem of the solar wind shock waves interaction with the ''bow wave-Earth's magnetosphere'' system is being solved. Considered are the secondary phenomena, as a result of which the depression-type wave occurs, that lowers the pressure on the Earth's maanetosphere. The law, governing the movement of the magnetosphere subsolar point during the abrupt start of a geomagnetic storm has been discovered. Stationary circumvention of the magnetosphere by the solar wind flux is well described by the gas dynamic theory of the hypersonic flux. Non-stationary interaction of the solar wind shock waves with the magnetosphere is magnetohydrodynamic. It is pointed out, that the problems under consideration are important for the forecasting of strong geomagnetic perturbations on the basis of cosmic observations

  18. The evaluation and management of electrical storm.

    Science.gov (United States)

    Eifling, Michael; Razavi, Mehdi; Massumi, Ali

    2011-01-01

    Electrical storm is an increasingly common and life-threatening syndrome that is defined by 3 or more sustained episodes of ventricular tachycardia, ventricular fibrillation, or appropriate shocks from an implantable cardioverter-defibrillator within 24 hours. The clinical presentation can be dramatic. Electrical storm can manifest itself during acute myocardial infarction and in patients who have structural heart disease, an implantable cardioverter-defibrillator, or an inherited arrhythmic syndrome. The presence or absence of structural heart disease and the electrocardiographic morphology of the presenting arrhythmia can provide important diagnostic clues into the mechanism of electrical storm. Electrical storm typically has a poor outcome.The effective management of electrical storm requires an understanding of arrhythmia mechanisms, therapeutic options, device programming, and indications for radiofrequency catheter ablation. Initial management involves determining and correcting the underlying ischemia, electrolyte imbalances, or other causative factors. Amiodarone and β-blockers, especially propranolol, effectively resolve arrhythmias in most patients. Nonpharmacologic treatment, including radiofrequency ablation, can control electrical storm in drug-refractory patients. Patients who have implantable cardioverter-defibrillators can present with multiple shocks and may require drug therapy and device reprogramming. After the acute phase of electrical storm, the treatment focus should shift toward maximizing heart-failure therapy, performing revascularization, and preventing subsequent ventricular arrhythmias. Herein, we present an organized approach for effectively evaluating and managing electrical storm.

  19. Vulnerability of Amazon forests to storm-driven tree mortality

    Science.gov (United States)

    Negrón-Juárez, Robinson I.; Holm, Jennifer A.; Magnabosco Marra, Daniel; Rifai, Sami W.; Riley, William J.; Chambers, Jeffrey Q.; Koven, Charles D.; Knox, Ryan G.; McGroddy, Megan E.; Di Vittorio, Alan V.; Urquiza-Muñoz, Jose; Tello-Espinoza, Rodil; Alegria Muñoz, Waldemar; Ribeiro, Gabriel H. P. M.; Higuchi, Niro

    2018-05-01

    Tree mortality is a key driver of forest community composition and carbon dynamics. Strong winds associated with severe convective storms are dominant natural drivers of tree mortality in the Amazon. Why forests vary with respect to their vulnerability to wind events and how the predicted increase in storm events might affect forest ecosystems within the Amazon are not well understood. We found that windthrows are common in the Amazon region extending from northwest (Peru, Colombia, Venezuela, and west Brazil) to central Brazil, with the highest occurrence of windthrows in the northwest Amazon. More frequent winds, produced by more frequent severe convective systems, in combination with well-known processes that limit the anchoring of trees in the soil, help to explain the higher vulnerability of the northwest Amazon forests to winds. Projected increases in the frequency and intensity of convective storms in the Amazon have the potential to increase wind-related tree mortality. A forest demographic model calibrated for the northwestern and the central Amazon showed that northwestern forests are more resilient to increased wind-related tree mortality than forests in the central Amazon. Our study emphasizes the importance of including wind-related tree mortality in model simulations for reliable predictions of the future of tropical forests and their effects on the Earth’ system.

  20. Storm warning : gambling with the climate of our planet

    Energy Technology Data Exchange (ETDEWEB)

    Dotto, L.

    1999-06-01

    This book gives a clear explanation of climate phenomena such as El Nino and the greenhouse effect, and provides a background and insight into the climate conferences held in recent years in Rio and Kyoto. It documents the extreme weather events of recent years, including the ice storm of 1998, the 1997 Manitoba floods, and the 1998 Atlantic hurricane season. Such events should prompt people to give serious thought to the implications of global warming and consider the strong evidence that our climate is changing due to human interference. The book warns that global warming will increase the frequency and severity of extreme weather events such as floods, droughts, and storm. Climate change is expected to affect agriculture, water supplies, food production, and the spread of human diseases. The book provides thoughtful answers to the major questions about global warming, detailed descriptions of the multiple effects on human health and safety, and discusses the steps that need to be taken to avoid and adapt to the oncoming storm. In answer to the non-believers, the author points out the futility of demanding more and more proof. In her view, we have all the proof needed, it is time to concentrate not on proof but on risk. refs.

  1. SLR-induced changes on storm flooding in coastal areas: the role of accommodation space

    Science.gov (United States)

    Jiménez, Jose A.; Dockx, Stijn; Monbaliu, Jaak

    2015-04-01

    Most of existing predictions of climate-induce changes in coastal storminess in the Mediterranean indicate the absence of any significant increasing trend in neither wave height nor surge. However, this does not mean that magnitude and/or frequency of storm-induced coastal hazards will not be affected by climate change. Thus, sea level rise will induce a series of long-term changes in coastal areas that although not directly affecting storminess will interact with storm-induced processes and, thus, changing coastal storm risks. A typical approach to account SLR-induced effects on coastal inundation by storms is to modify present water level extreme climate by adding expected MWL increase. This implies to consider the coast as a static and passive system to SLR maintaining its configuration from actual to projected (rised) sea level and, as a result of this, the frequency of flood events should increase and, the magnitude of flooding associated to a probability of occurrence will also increase. This will only be realistic for really passive or rigid coasts. However, sandy coastlines will response to SLR and, thus, this approach should undervalue coastal resilience. Within this context, the main aim of this work is to propose a method to assess the effects of SLR on the magnitude of storm-induced coastal flooding on sandy coastlines taking into account their capacity of response. It combines the use of a inundation model (LISFLOOD-FP) for delineating the flood-prone area for given storm conditions and, a coastal module to account for SLR-induced changes in the coastal fringe. The method assumes an equilibrium-type coastal response to SLR which, ideally, implies that the beach profile will be reconstructed under the new higher water level, in such a way that the relative beach configuration will be the same. However, this should only be possible provided there is enough accommodation space in the hinterland. In most of developed coasts, the existence of human built

  2. Observations by the CUTLASS radar, HF Doppler, oblique ionospheric sounding, and TEC from GPS during a magnetic storm

    Directory of Open Access Journals (Sweden)

    D. V. Blagoveshchensky

    2005-07-01

    Full Text Available Multi-diagnostic observations, covering a significant area of northwest Europe, were made during the magnetic storm interval (28–29 April 2001 that occurred during the High Rate SolarMax IGS/GPS-campaign. HF radio observations were made with vertical sounders (St. Petersburg and Sodankyla, oblique incidence sounders (OIS, on paths from Murmansk to St. Petersburg, 1050 km, and Inskip to Leicester, 170 km, Doppler sounders, on paths from Cyprus to St. Petersburg, 2800 km, and Murmansk to St. Petersburg, and a coherent scatter radar (CUTLASS, Hankasalmi, Finland. These, together with total electron content (TEC measurements made at GPS stations from the Euref network in northwest Europe, are presented in this paper. A broad comparison of radio propagation data with ionospheric data at high and mid latitudes, under quiet and disturbed conditions, was undertaken. This analysis, together with a geophysical interpretation, allow us to better understand the nature of the ionospheric processes which occur during geomagnetic storms. The peculiarity of the storm was that it comprised of three individual substorms, the first of which appears to have been triggered by a compression of the magnetosphere. Besides the storm effects, we have also studied substorm effects in the observations separately, providing an improved understanding of the storm/substorm relationship. The main results of the investigations are the following. A narrow trough is formed some 10h after the storm onset in the TEC which is most likely a result of enhanced ionospheric convection. An enhancement in TEC some 2–3 h after the storm onset is most likely a result of heating and upwelling of the auroral ionosphere caused by enhanced currents. The so-called main effect on ionospheric propagation was observed at mid-latitudes during the first two substorms, but only during the first substorm at high latitudes. Ionospheric irregularities observed by CUTLASS were clearly related to the

  3. Storm and hurricane disturbances on phosphorus storage within an in-stream wetland

    Science.gov (United States)

    The ability of wetlands to hold phosphorus (P) makes them and important landscape feature that help to protect water quality. However, their ability to retain P can be affected through hydrologic disturbances caused by both storms and flooding. An animal waste impacted in-stream wetland (ISW) locate...

  4. Ionosphere-thermosphere energy budgets for the ICME storms of March 2013 and 2015 estimated with GITM and observational proxies

    Science.gov (United States)

    Verkhoglyadova, O. P.; Meng, X.; Mannucci, A. J.; Mlynczak, M. G.; Hunt, L. A.; Lu, G.

    2017-09-01

    The ionosphere-thermosphere (IT) energy partitioning for the interplanetary coronal mass ejection (ICME) storms of 16-19 March 2013 and 2015 is estimated with the Global Ionosphere-Thermosphere Model (GITM), empirical models and proxies derived from in situ measurements. We focus on auroral heating, Joule heating, and thermospheric cooling. Solar wind data, F10.7, OVATION Prime model and the Weimer 2005 model are used to drive GITM from above. Thermospheric nitric oxide and carbon dioxide cooling emission powers and fluxes are estimated from TIMED/SABER measurements. Assimilative mapping of ionospheric electrodynamics (AMIE) estimations of hemispheric power and Joule heating are presented, based on data from global magnetometers, the AMPERE magnetic field data, SSUSI auroral images, and the SuperDARN radar network. Modeled Joule heating and auroral heating of the IT system are mostly controlled by external driving in the March 2013 and 2015 storms, while NO cooling persists into the storm recovery phase. The total heating in the model is about 1000 GW to 3000 GW. Additionally, we intercompare contributions in selected energy channels for five coronal mass ejection-type storms modeled with GITM. Modeled auroral heating shows reasonable agreement with AMIE hemispheric power and is higher than other observational proxies. Joule heating and infrared cooling are likely underestimated in GITM. We discuss challenges and discrepancies in estimating and global modeling of the IT energy partitioning, especially Joule heating, during geomagnetic storms.

  5. Northeast storms ranked by wind stress and wave-generated bottom stress observed in Massachusetts Bay, 1990-2006

    Science.gov (United States)

    Butman, B.; Sherwood, C.R.; Dalyander, P.S.

    2008-01-01

    Along the coast of the northeastern United States, strong winds blowing from the northeast are often associated with storms called northeasters, coastal storms that strongly influence weather. In addition to effects caused by wind stress, the sea floor is affected by bottom stress associated with these storms. Bottom stress caused by orbital velocities associated with surface waves integrated over the duration of a storm is a metric of storm strength at the sea floor. Near-bottom wave-orbital velocities calculated by using measurements of significant wave height and dominant wave period and the parametric spectral method described in Wiberg and Sherwood [Wiberg, P.L., Sherwood, C.R. Calculating wave-generated bottom orbital velocities from surface wave parameters. Computers in Geosciences, in press] compared well with observations in Massachusetts Bay. Integrated bottom-wave stress (called IWAVES), calculated at 30 m water depth, and a companion storm-strength metric, integrated surface wind stress at 10 m (called IWINDS), are used to provide an overview of the strength, frequency, and timing of large storms in Massachusetts Bay over a 17-year period from January 1990 through December 2006. These new metrics reflect both storm duration and intensity. Northeast storms were the major cause of large waves in Massachusetts Bay because of the long fetch to the east: of the strongest 10% of storms (n=38) ranked by IWAVES, 22 had vector-averaged wind stress from the northeast quadrant. The Blizzard of December 1992, the Perfect Storm of October 1991, and a December 2003 storm were the strongest three storms ranked by IWAVES and IWINDS, and all were northeasters. IWAVES integrated over the winter season (defined as October-May) ranged by about a factor of 11; the winters with the highest integrated IWAVES were 1992-1993 and 2004-2005 and the winter with the lowest integrated IWAVES was 2001-2002. May 2005 was the only month in the 17-year record that two of the nine

  6. High-resolution refinement of a storm loss model and estimation of return periods of loss-intensive storms over Germany

    Directory of Open Access Journals (Sweden)

    M. G. Donat

    2011-10-01

    Full Text Available A refined model for the calculation of storm losses is presented, making use of high-resolution insurance loss records for Germany and allowing loss estimates on a spatial level of administrative districts and for single storm events. Storm losses are calculated on the basis of wind speeds from both ERA-Interim and NCEP reanalyses. The loss model reproduces the spatial distribution of observed losses well by taking specific regional loss characteristics into account. This also permits high-accuracy estimates of total cumulated losses, though slightly underestimating the country-wide loss sums for storm "Kyrill", the most severe event in the insurance loss records from 1997 to 2007. A larger deviation, which is assigned to the relatively coarse resolution of the NCEP reanalysis, is only found for one specific rather small-scale event, not adequately captured by this dataset.

    The loss model is subsequently applied to the complete reanalysis period to extend the storm event catalogue to cover years when no systematic insurance records are available. This allows the consideration of loss-intensive storm events back to 1948, enlarging the event catalogue to cover the recent 60+ years, and to investigate the statistical characteristics of severe storm loss events in Germany based on a larger sample than provided by the insurance records only. Extreme value analysis is applied to the loss data to estimate the return periods of loss-intensive storms, yielding a return period for storm "Kyrill", for example, of approximately 15 to 21 years.

  7. The impact of dust storms on the Arabian Peninsula and the Red Sea

    KAUST Repository

    Jish Prakash, P.

    2015-01-12

    Located in the dust belt, the Arabian Peninsula is a major source of atmospheric dust. Frequent dust outbreaks and some 15 to 20 dust storms per year have profound effects on all aspects of human activity and natural processes in this region. To quantify the effect of severe dust events on radiation fluxes and regional climate characteristics, we simulated the storm that occurred from 18 to 20 March 2012 using a regional weather research forecast model fully coupled with the chemistry/aerosol module (WRF–Chem). This storm swept over a remarkably large area affecting the entire Middle East, northeastern Africa, Afghanistan, and Pakistan. It was caused by a southward propagating cold front, and the associated winds activated the dust production in river valleys of the lower Tigris and Euphrates in Iraq; the coastal areas in Kuwait, Iran, and the United Arab Emirates; the Rub al Khali, An Nafud, and Ad Dahna deserts; and along the Red Sea coast on the west side of the Arabian Peninsula. Our simulation results compare well with available ground-based and satellite observations. We estimate the total amount of dust generated by the storm to have reached 94 Mt. Approximately 78% of this dust was deposited within the calculation domain. The Arabian Sea and Persian Gulf received 5.3 Mt and the Red Sea 1.2 Mt of dust. Dust particles bring nutrients to marine ecosystems, which is especially important for the oligotrophic Northern Red Sea. However, their contribution to the nutrient balance in the Red Sea remains largely unknown. By scaling the effect of one storm to the number of dust storms observed annually over the Red Sea, we estimate the annual dust deposition to the Red Sea, associated with major dust storms, to be 6 Mt.

  8. Storms do not alter long-term watershed development influences on coastal water quality.

    Science.gov (United States)

    Chen, Yushun; Cebrian, Just; Lehrter, John; Christiaen, Bart; Stutes, Jason; Goff, Josh

    2017-09-15

    A twelve year (2000-2011) study of three coastal lagoons in the Gulf of Mexico was conducted to assess the impacts of local watershed development and tropical storms on water quality. The lagoons have similar physical and hydrological characteristics, but differ substantially in the degree of watershed urban development and nutrient loading rates. In total the lagoons experienced 22 storm events during the period studied. Specifically, we examine (1) whether there are influences on water quality in the lagoons from watershed development, (2) whether there are influences on water quality in the lagoons from storm activity, and (3) whether water quality is affected to a greater degree by watershed development versus storm activity. The two urbanized lagoons typically showed higher water-column nitrate, dissolved organic nitrogen, and phosphate compared with the non-urbanized lagoon. One of the urbanized lagoons had higher water-column chlorophyll a concentrations than the other two lagoons on most sampling dates, and higher light extinction coefficients on some sampling dates. The non-urbanized lagoon had higher water-column dissolved oxygen concentrations than other lagoons on many sampling dates. Our results suggest long-term influences of watershed development on coastal water quality. We also found some evidence of significant storm effects on water quality, such as increased nitrate, phosphate, and dissolved oxygen, and decreased salinity and water temperature. However, the influences of watershed development on water quality were greater. These results suggest that changes in water quality induced by human watershed development pervade despite the storm effects. These findings may be useful for environmental management since they suggest that storms do not profoundly alter long-term changes in water quality that resulted from human development of watersheds. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. The impact of dust storms on the Arabian Peninsula and the Red Sea

    KAUST Repository

    Jish Prakash, P.; Stenchikov, Georgiy L.; Kalenderski, Stoitchko; Osipov, Sergey; Bangalath, Hamza Kunhu

    2015-01-01

    Located in the dust belt, the Arabian Peninsula is a major source of atmospheric dust. Frequent dust outbreaks and some 15 to 20 dust storms per year have profound effects on all aspects of human activity and natural processes in this region. To quantify the effect of severe dust events on radiation fluxes and regional climate characteristics, we simulated the storm that occurred from 18 to 20 March 2012 using a regional weather research forecast model fully coupled with the chemistry/aerosol module (WRF–Chem). This storm swept over a remarkably large area affecting the entire Middle East, northeastern Africa, Afghanistan, and Pakistan. It was caused by a southward propagating cold front, and the associated winds activated the dust production in river valleys of the lower Tigris and Euphrates in Iraq; the coastal areas in Kuwait, Iran, and the United Arab Emirates; the Rub al Khali, An Nafud, and Ad Dahna deserts; and along the Red Sea coast on the west side of the Arabian Peninsula. Our simulation results compare well with available ground-based and satellite observations. We estimate the total amount of dust generated by the storm to have reached 94 Mt. Approximately 78% of this dust was deposited within the calculation domain. The Arabian Sea and Persian Gulf received 5.3 Mt and the Red Sea 1.2 Mt of dust. Dust particles bring nutrients to marine ecosystems, which is especially important for the oligotrophic Northern Red Sea. However, their contribution to the nutrient balance in the Red Sea remains largely unknown. By scaling the effect of one storm to the number of dust storms observed annually over the Red Sea, we estimate the annual dust deposition to the Red Sea, associated with major dust storms, to be 6 Mt.

  10. Forest structure and light regimes following moderate wind storms: implications for multi-cohort management.

    Science.gov (United States)

    Hanson, Jacob J; Lorimer, Craig G

    2007-07-01

    Moderate-severity disturbances appear to be common throughout much of North America, but they have received relatively little detailed study compared to catastrophic disturbances and small gap dynamics. In this study, we examined the immediate impact of moderate-intensity wind storms on stand structure, opening sizes, and light regimes in three hemlock-hardwood forests of northeastern Wisconsin. These were compared to three stands managed by single-tree and group selection, the predominant forest management system for northern hardwoods in the region. Wind storms removed an average of 41% of the stand basal area, compared to 27% removed by uneven-aged harvests, but both disturbances removed trees from a wide range of size classes. The removal of nearly half of the large trees by wind in two old-growth stands caused partial retrogression to mature forest structure, which has been hypothesized to be a major disturbance pathway in the region. Wind storms resulted in residual stand conditions that were much more heterogeneous than in managed stands. Gap sizes ranged from less than 10 m2 up to 5000 m2 in wind-disturbed stands, whereas the largest opening observed in managed stands was only 200 m2. Wind-disturbed stands had, on average, double the available solar radiation at the forest floor compared to managed stands. Solar radiation levels were also more heterogeneous in wind-disturbed stands, with six times more variability at small scales (0.1225 ha) and 15 times more variability at the whole-stand level. Modification of uneven-aged management regimes to include occasional harvests of variable intensity and spatial pattern may help avoid the decline in species diversity that tends to occur after many decades of conventional uneven-aged management. At the same time, a multi-cohort system with these properties would retain a high degree of average crown cover, promote structural heterogeneity typical of old-growth forests, and maintain dominance by late

  11. Storm real-time processing cookbook

    CERN Document Server

    Anderson, Quinton

    2013-01-01

    A Cookbook with plenty of practical recipes for different uses of Storm.If you are a Java developer with basic knowledge of real-time processing and would like to learn Storm to process unbounded streams of data in real time, then this book is for you.

  12. Stochastic Optical Reconstruction Microscopy (STORM).

    Science.gov (United States)

    Xu, Jianquan; Ma, Hongqiang; Liu, Yang

    2017-07-05

    Super-resolution (SR) fluorescence microscopy, a class of optical microscopy techniques at a spatial resolution below the diffraction limit, has revolutionized the way we study biology, as recognized by the Nobel Prize in Chemistry in 2014. Stochastic optical reconstruction microscopy (STORM), a widely used SR technique, is based on the principle of single molecule localization. STORM routinely achieves a spatial resolution of 20 to 30 nm, a ten-fold improvement compared to conventional optical microscopy. Among all SR techniques, STORM offers a high spatial resolution with simple optical instrumentation and standard organic fluorescent dyes, but it is also prone to image artifacts and degraded image resolution due to improper sample preparation or imaging conditions. It requires careful optimization of all three aspects-sample preparation, image acquisition, and image reconstruction-to ensure a high-quality STORM image, which will be extensively discussed in this unit. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  13. Examples of storm impacts on barrier islands: Chapter 4

    Science.gov (United States)

    Plant, Nathaniel G.; Doran, Kara; Stockdon, Hilary F.

    2017-01-01

    This chapter focuses on the morphologic variability of barrier islands and on the differences in storm response. It describes different types of barrier island response to individual storms, as well as the integrated response of barrier islands to many storms. The chapter considers case study on the Chandeleur Island chain, where a decadal time series of island elevation measurements have documented a wide range of barrier island responses to storms and long-term processes that are representative of barrier island behaviour at many other locations. These islands are low elevation, extremely vulnerable to storms and exhibit a diversity of storm responses. Additionally, this location experiences a moderately high rate of relative sea-level rise, increasing its vulnerability to the combined impacts of storms and long-term erosional processes. Understanding how natural processes, including storm impacts and intervening recovery periods interact with man-made restoration processes is also broadly relevant to understand the natural and human response to future storms.

  14. Impacts of a Destructive and Well-Observed Cross-Country Winter Storm.

    Science.gov (United States)

    Martner, Brooks E.; Rauber, Robert M.; Ramamurthy, Mohan K.; Rasmussen, Roy M.; Prater, Erwin T.

    1992-02-01

    A winter storm that crossed the continental United States in mid-February 1990 produced hazardous weather across a vast area of the nation. A wide range of severe weather was reported, including heavy snowfall; freezing rain and drizzle; thunderstorms with destructive winds, lightning, large hail, and tornadoes; prolonged heavy rain with subsequent flooding; frost damage to citrus orchards; and sustained destructive winds not associated with thunderstorms. Low-end preliminary estimates of impacts included 9 deaths, 27 injuries, and $120 million of property damage. At least 35 states and southeastern Canada were adversely affected. The storm occurred during the field operations of four independent atmospheric research projects that obtained special, detailed observations of it from the Rocky Mountains to the eastern great Lakes.

  15. Earlier vegetation green-up has reduced spring dust storms.

    Science.gov (United States)

    Fan, Bihang; Guo, Li; Li, Ning; Chen, Jin; Lin, Henry; Zhang, Xiaoyang; Shen, Miaogen; Rao, Yuhan; Wang, Cong; Ma, Lei

    2014-10-24

    The observed decline of spring dust storms in Northeast Asia since the 1950s has been attributed to surface wind stilling. However, spring vegetation growth could also restrain dust storms through accumulating aboveground biomass and increasing surface roughness. To investigate the impacts of vegetation spring growth on dust storms, we examine the relationships between recorded spring dust storm outbreaks and satellite-derived vegetation green-up date in Inner Mongolia, Northern China from 1982 to 2008. We find a significant dampening effect of advanced vegetation growth on spring dust storms (r = 0.49, p = 0.01), with a one-day earlier green-up date corresponding to a decrease in annual spring dust storm outbreaks by 3%. Moreover, the higher correlation (r = 0.55, p storm outbreak ratio (the ratio of dust storm outbreaks to times of strong wind events) indicates that such effect is independent of changes in surface wind. Spatially, a negative correlation is detected between areas with advanced green-up dates and regional annual spring dust storms (r = -0.49, p = 0.01). This new insight is valuable for understanding dust storms dynamics under the changing climate. Our findings suggest that dust storms in Inner Mongolia will be further mitigated by the projected earlier vegetation green-up in the warming world.

  16. Identification of storm surge vulnerable areas in the Philippines through the simulation of Typhoon Haiyan-induced storm surge levels over historical storm tracks

    Science.gov (United States)

    Lapidez, J. P.; Tablazon, J.; Dasallas, L.; Gonzalo, L. A.; Cabacaba, K. M.; Ramos, M. M. A.; Suarez, J. K.; Santiago, J.; Lagmay, A. M. F.; Malano, V.

    2015-07-01

    Super Typhoon Haiyan entered the Philippine Area of Responsibility (PAR) on 7 November 2013, causing tremendous damage to infrastructure and loss of lives mainly due to the storm surge and strong winds. Storm surges up to a height of 7 m were reported in the hardest hit areas. The threat imposed by this kind of natural calamity compelled researchers of the Nationwide Operational Assessment of Hazards (Project NOAH) which is the flagship disaster mitigation program of the Department of Science and Technology (DOST) of the Philippine government to undertake a study to determine the vulnerability of all Philippine coastal communities to storm surges of the same magnitude as those generated by Haiyan. This study calculates the maximum probable storm surge height for every coastal locality by running simulations of Haiyan-type conditions but with tracks of tropical cyclones that entered PAR from 1948-2013. One product of this study is a list of the 30 most vulnerable coastal areas that can be used as a basis for choosing priority sites for further studies to implement appropriate site-specific solutions for flood risk management. Another product is the storm tide inundation maps that the local government units can use to develop a risk-sensitive land use plan for identifying appropriate areas to build residential buildings, evacuation sites, and other critical facilities and lifelines. The maps can also be used to develop a disaster response plan and evacuation scheme.

  17. Identification of storm surge vulnerable areas in the Philippines through the simulation of Typhoon Haiyan-induced storm surge levels over historical storm tracks

    Directory of Open Access Journals (Sweden)

    J. P. Lapidez

    2015-07-01

    Full Text Available Super Typhoon Haiyan entered the Philippine Area of Responsibility (PAR on 7 November 2013, causing tremendous damage to infrastructure and loss of lives mainly due to the storm surge and strong winds. Storm surges up to a height of 7 m were reported in the hardest hit areas. The threat imposed by this kind of natural calamity compelled researchers of the Nationwide Operational Assessment of Hazards (Project NOAH which is the flagship disaster mitigation program of the Department of Science and Technology (DOST of the Philippine government to undertake a study to determine the vulnerability of all Philippine coastal communities to storm surges of the same magnitude as those generated by Haiyan. This study calculates the maximum probable storm surge height for every coastal locality by running simulations of Haiyan-type conditions but with tracks of tropical cyclones that entered PAR from 1948–2013. One product of this study is a list of the 30 most vulnerable coastal areas that can be used as a basis for choosing priority sites for further studies to implement appropriate site-specific solutions for flood risk management. Another product is the storm tide inundation maps that the local government units can use to develop a risk-sensitive land use plan for identifying appropriate areas to build residential buildings, evacuation sites, and other critical facilities and lifelines. The maps can also be used to develop a disaster response plan and evacuation scheme.

  18. Unexpected Southern Hemisphere ionospheric response to geomagnetic storm of 15 August 2015

    Directory of Open Access Journals (Sweden)

    I. Edemskiy

    2018-01-01

    Full Text Available Geomagnetic storms are the most pronounced phenomenon of space weather. When studying ionospheric response to a storm of 15 August 2015, an unexpected phenomenon was observed at higher middle latitudes of the Southern Hemisphere. This phenomenon was a localized total electron content (TEC enhancement (LTE in the form of two separated plumes, which peaked southward of South Africa. The plumes were first observed at 05:00 UT near the southwestern coast of Australia. The southern plume was associated with local time slightly after noontime (1–2 h after local noon. The plumes moved with the Sun. They peaked near 13:00 UT southward of South Africa. The southern plume kept constant geomagnetic latitude (63–64° S; it persisted for about 10 h, whereas the northern plume persisted for about 2 h more. Both plumes disappeared over the South Atlantic Ocean. No similar LTE event was observed during the prolonged solar activity minimum period of 2006–2009. In 2012–2016 we detected altogether 26 LTEs and all of them were associated with the southward excursion of Bz. The negative Bz excursion is a necessary but not sufficient condition for the LTE occurrence as during some geomagnetic storms associated with negative Bz excursions the LTE events did not appear.

  19. Storm surges and climate change implications for tidal marshes: Insight from the San Francisco Bay Estuary, California, USA

    Science.gov (United States)

    Thorne, Karen M.; Buffington, Kevin J.; Swanson, Kathleen; Takekawa, John Y.

    2013-01-01

    Tidal marshes are dynamic ecosystems, which are influenced by oceanic and freshwater processes and daily changes in sea level. Projected sea-level rise and changes in storm frequency and intensity will affect tidal marshes by altering suspended sediment supply, plant communities, and the inundation duration and depth of the marsh platform. The objective of this research was to evaluate if regional weather conditions resulting in low-pressure storms changed tidal conditions locally within three tidal marshes. We hypothesized that regional storms will increase sea level heights locally, resulting in increased inundation of the tidal marsh platform and plant communities. Using site-level measurements of elevation, plant communities, and water levels, we present results from two storm events in 2010 and 2011 from the San Francisco Bay Estuary (SFBE), California, USA. The January 2010 storm had the lowest recorded sea level pressure in the last 30 years for this region. During the storm episodes, the duration of tidal marsh inundation was 1.8 and 3.1 times greater than average for that time of year, respectively. At peak storm surges, over 65% in 2010 and 93% in 2011 of the plant community was under water. We also discuss the implications of these types of storms and projected sea-level rise on the structure and function of the tidal marshes and how that will impact the hydro-geomorphic processes and marsh biotic communities.

  20. Effect of geomagnetic storm conditions on the equatorial ionization anomaly and equatorial temperature anomaly

    Science.gov (United States)

    Bharti, Gaurav; Bag, T.; Sunil Krishna, M. V.

    2018-03-01

    The effect of the geomagnetic storm on the equatorial ionization anomaly (EIA) and equatorial temperature anomaly (ETA) has been studied using the atomic oxygen dayglow emissions at 577.7 nm (OI 557.7 nm) and 732.0 nm (OII 732.0 nm). For the purpose of this study, four intense geomagnetic storms during the ascending phase of solar cycle 24 have been considered. This study is primarily based on the results obtained using photochemical models with necessary inputs from theoretical studies and experimental observations. The latest reaction rate coefficients, quantum yields and the corresponding cross-sections have also been incorporated in these models. The volume emission rate of airglow emissions has been calculated using the neutral densities from NRLMSISE-00 and charged densities from IRI-2012 model. The modeled volume emission rate (VER) for OI 557.7 nm shows a positive correlation with the Dst index at 150 km and negative correlation with Dst at 250 and 280 km altitudes. Latitudinal profile of the greenline emission rate at different altitudes show a distinct behaviour similar to what has been observed in EIA with crests on either sides of the equator. The EIA crests are found to show poleward movement in the higher altitude regions. The volume emission rate of 732.0 nm emission shows a strong enhancement during the main phase of the storm. The changes observed in the airglow emission rates are explained with the help of variations induced in neutral densities and parameters related to EIA and ETA. The latitudinal variation of 732.0 nm emission rate is correlated to the variability in EIA during the storm period.

  1. Do Solar Coronal Holes Affect the Properties of Solar Energetic Particle Events?

    Science.gov (United States)

    Kahler, S. W.; Arge, C. N.; Akiyama, S.; Gopalswamy, N.

    2013-01-01

    The intensities and timescales of gradual solar energetic particle (SEP) events at 1 AU may depend not only on the characteristics of shocks driven by coronal mass ejections (CMEs), but also on large-scale coronal and interplanetary structures. It has long been suspected that the presence of coronal holes (CHs) near the CMEs or near the 1-AU magnetic footpoints may be an important factor in SEP events. We used a group of 41 E (is) approx. 20 MeV SEP events with origins near the solar central meridian to search for such effects. First we investigated whether the presence of a CH directly between the sources of the CME and of the magnetic connection at 1 AU is an important factor. Then we searched for variations of the SEP events among different solar wind (SW) stream types: slow, fast, and transient. Finally, we considered the separations between CME sources and CH footpoint connections from 1 AU determined from four-day forecast maps based on Mount Wilson Observatory and the National Solar Observatory synoptic magnetic-field maps and the Wang-Sheeley-Arge model of SW propagation. The observed in-situ magnetic-field polarities and SW speeds at SEP event onsets tested the forecast accuracies employed to select the best SEP/CH connection events for that analysis. Within our limited sample and the three analytical treatments, we found no statistical evidence for an effect of CHs on SEP event peak intensities, onset times, or rise times. The only exception is a possible enhancement of SEP peak intensities in magnetic clouds.

  2. Development of Storm Surge Hazard Maps and Advisory System for the Philippines

    Science.gov (United States)

    Santiago, Joy; Mahar Francisco Lagymay, Alfredo; Caro, Carl Vincent; Suarez, John Kenneth; Tablazon, Judd; Dasallas, Lea; Garnet Goting, Prince

    2016-04-01

    The Philippines, located in the most active region of cyclogenesis in the world, experiences an average of 20 tropical cyclones annually. Strong winds brought by tropical cyclones, among other factors, cause storm surges that inundate the coastal areas of the country. As an archipelago with the fourth longest coastline in the world, the country is expose to the threats of storm surges. This was manifested by Typhoon Haiyan on 8 November 2013, which devastated the country and left 6,293 deaths and approximately USD 2 billion worth of damages. To prevent such disaster from happening again, the Nationwide Operational Assessment of Hazards (Project NOAH) developed a Storm Surge Advisory (SSA) that aims to warn communities in coastal areas against impending floods due to storm surges. The Japan Meteorological Agency storm surge model was used to simulate 721 tropical cyclones that entered the Philippine Area of Responsibility from 1951-2013. The resulting storm surge time series from the simulations were added to the maximum tide levels from the WXTide software for the 4,996 observation points placed nearshore in the entire country. The storm tide levels were categorized into four groups based on their peak height to create the SSA - SSA 1 (0.01m to 2m), SSA 2 (2.01m to 3m), SSA 3 (3.01m to 4m), and SSA 4 (4m and above). The time series for each advisory level was used in inundation modelling using FLO-2D, a two-dimensional flood modeling software that uses continuity and dynamic wave momentum equation. The model produced probable extent, depth of inundation, and hazard level for each advisory level. The SSA hazard maps are used as reference to warn communities that are likely to be affected by storm surges. Advisory is released 24 hours in advance and is updated every six hours in the Project NOAH website. It is also being utilized in the pre-disaster risk assessment of the national government agencies and local government units in designing appropriate response to

  3. The storm time central plasma sheet

    Directory of Open Access Journals (Sweden)

    R. Schödel

    2002-11-01

    Full Text Available The plasma sheet plays a key role during magnetic storms because it is the bottleneck through which large amounts of magnetic flux that have been eroded from the dayside magnetopause have to be returned to the dayside magnetosphere. Using about five years of Geotail data we studied the average properties of the near- and midtail central plasma sheet (CPS in the 10–30 RE range during magnetic storms. The earthward flux transport rate is greatly enhanced during the storm main phase, but shows a significant earthward decrease. Hence, since the magnetic flux cannot be circulated at a sufficient rate, this leads to an average dipolarization of the central plasma sheet. An increase of the specific entropy of the CPS ion population by a factor of about two during the storm main phase provides evidence for nonadiabatic heating processes. The direction of flux transport during the main phase is consistent with the possible formation of a near-Earth neutral line beyond ~20 RE.Key words. Magnetospheric physics (plasma convection; plasma sheet; storms and substorms

  4. Study of the Equatorial and Low-Latitude Electrodynamic and Ionospheric Disturbances During the 22-23 June 2015 Geomagnetic Storm Using Ground-Based and Spaceborne Techniques

    Science.gov (United States)

    Astafyeva, E.; Zakharenkova, I.; Hozumi, K.; Alken, P.; Coïsson, P.; Hairston, M. R.; Coley, W. R.

    2018-03-01

    We use a set of ground-based instruments (Global Positioning System receivers, ionosondes, magnetometers) along with data of multiple satellite missions (Swarm, C/NOFS, DMSP, GUVI) to analyze the equatorial and low-latitude electrodynamic and ionospheric disturbances caused by the geomagnetic storm of 22-23 June 2015, which is the second largest storm in the current solar cycle. Our results show that at the beginning of the storm, the equatorial electrojet (EEJ) and the equatorial zonal electric fields were largely impacted by the prompt penetration electric fields (PPEF). The PPEF were first directed eastward and caused significant ionospheric uplift and positive ionospheric storm on the dayside, and downward drift on the nightside. Furthermore, about 45 min after the storm commencement, the interplanetary magnetic field (IMF) Bz component turned northward, leading to the EEJ changing sign to westward, and to overall decrease of the vertical total electron content (VTEC) and electron density on the dayside. At the end of the main phase of the storm, and with the second long-term IMF Bz southward turn, we observed several oscillations of the EEJ, which led us to conclude that at this stage of the storm, the disturbance dynamo effect was already in effect, competing with the PPEF and reducing it. Our analysis showed no significant upward or downward plasma motion during this period of time; however, the electron density and the VTEC drastically increased on the dayside (over the Asian region). We show that this second positive storm was largely influenced by the disturbed thermospheric conditions.

  5. Controlling of merging electric field and IMF magnitude on storm-time changes in thermospheric mass density

    Directory of Open Access Journals (Sweden)

    Y. L. Zhou

    2013-01-01

    Full Text Available The controls of merging electrical field, Em, and IMF (interplanetary magnetic field magnitude, B, on the storm-time changes in upper thermospheric mass density are statistically investigated using GRACE accelerometer observations and the OMNI data of solar wind and IMF for 35 great storms during 2002–2006. It reveals the following: (1 The correlation coefficients between the air mass density changes and the parameters of Em and B are generally larger at lower latitudes than at higher latitudes, and larger in noon and midnight sectors than in dawn and dusk. (2 The most likely delay time (MLDT of mass density changes in respect to Em is about 1.5 h (4.5 h at high (low latitudes, having no distinct local time dependence, while it is 6 h at middle latitudes in all the local time sectors except for noon, which is longer than at low latitudes. A similar fact of longer delay time at mid-latitude is also seen for B. The MLDTs for B at various latitudes are all local time dependent distinctly with shorter delay time in noon/midnight sector and larger in dawn/dusk. Despite of widely spread of the delay time, IMF B exhibits still larger correlation coefficients with mass density changes among the interplanetary parameters. (3 The linear control factor of B on the density changes increases for large B, in contrast to somewhat saturation trend for larger Em. (4 The influence of B and Em on the mass densities shows different behavior for different types of storms. The influence intensity of Em is much stronger for CIR-driven than for CME-driven storm, while it is not so distinct for B. On the local time asymmetry of the influence, both Em and B have largest influence at noon sector for CME-driven storms, while an obviously larger intensification of the influence is found in dawn/dusk sector during CIR storms, especially for parameter Em.

  6. Rain storm models and the relationship between their parameters

    NARCIS (Netherlands)

    Stol, P.T.

    1977-01-01

    Rainfall interstation correlation functions can be obtained with the aid of analytic rainfall or storm models. Since alternative storm models have different mathematical formulas, comparison should be based on equallity of parameters like storm diameter, mean rainfall amount, storm maximum or total

  7. 46 CFR 190.25-10 - Storm rails.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Storm rails. 190.25-10 Section 190.25-10 Shipping COAST... ARRANGEMENT Rails and Guards § 190.25-10 Storm rails. (a) On vessels in ocean and coastwise service, suitable storm rails shall be installed in all passageways and at the deckhouse sides where persons on board...

  8. 40 CFR 35.925-21 - Storm sewers.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Storm sewers. 35.925-21 Section 35.925... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act § 35.925-21 Storm... treatment works for control of pollutant discharges from a separate storm sewer system (as defined in § 35...

  9. 46 CFR 92.25-10 - Storm rails.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Storm rails. 92.25-10 Section 92.25-10 Shipping COAST... ARRANGEMENT Rails and Guards § 92.25-10 Storm rails. (a) On vessels in ocean and coastwise service, suitable storm rails shall be installed in all passageways and at the deckhouse sides where persons on board...

  10. New storm water regulations impact industry

    International Nuclear Information System (INIS)

    Gemar, C.

    1991-01-01

    In November 1990, new Environmental Protection Agency (EPA) regulations aimed at governing the discharge of storm water from industrial facilities became effective. Because some industrial runoff contains toxics and other pollutants, the EPA considers storm water a major source of water contamination. The new regulations will have a profound impact on the National Pollutant Discharge Elimination System (NPDES) permit requirements for industry. This paper summarizes the new storm water regulations, focusing on the requirements for industrial facilities. It also presents suggestions for compliance

  11. Monitoring Hurricane Rita Inland Storm Surge: Chapter 7J in Science and the storms-the USGS response to the hurricanes of 2005

    Science.gov (United States)

    McGee, Benton D.; Tollett, Roland W.; Goree, Burl B.

    2007-01-01

    Pressure transducers (sensors) are accurate, reliable, and cost-effective tools to measure and record the magnitude, extent, and timing of hurricane storm surge. Sensors record storm-surge peaks more accurately and reliably than do high-water marks. Data collected by sensors may be used in storm-surge models to estimate when, where, and to what degree stormsurge flooding will occur during future storm-surge events and to calibrate and verify stormsurge models, resulting in a better understanding of the dynamics of storm surge.

  12. Wonders of the solar system

    CERN Document Server

    Cox, Brian

    2011-01-01

    The Sunday Times Bestseller In Wonders of the Solar System - the book of the acclaimed BBC TV series - Professor Brian Cox will take us on a journey of discovery where alien worlds from your imagination become places we can see, feel and visit. The Wonders of the Solar System - from the giant ice fountains of Enceladus to the liquid methane seas of Titan and from storms twice the size of the Earth to the tortured moon of Io with its giant super-volcanoes - is the Solar System as you have never seen it before. In this series, Professor Brian Cox will introduce us to the planets and moons beyond our world, finding the biggest, most bizarre, most powerful natural phenomena. Using the latest scientific imagery along with cutting edge CGI and some of the most spectacular and extreme locations on Earth, Brian will show us Wonders never thought possible. Employing his trademark clear, authoritative, yet down-to-earth approach, Brian will explore how these previously unseen phenomena have dramatically expanded our ho...

  13. Effect of solar flare on the equatorial electrojet in eastern Brazil region

    Indian Academy of Sciences (India)

    The effect of solar flare, sudden commencement of magnetic storm and of the disturbances ring current on the equatorial electrojet in the Eastern Brazil region, where the ground magnetic declination is as large as 20∘W is studied based on geomagnetic data with one minute resolution from Bacabal during ...

  14. VTEC behavior in the American sector during high solar activity

    CERN Document Server

    Ezquer, R G; Brunini, C; Conicet; Meza, A; Mosert, M; Radicella, S M

    2002-01-01

    The behavior of the vertical total electron content (VTEC) obtained from GPS signals received during the high solar activity year 1999 at stations placed in the American sector, is reported. The considered latitude range extends from 18.4 to -64.7 and the longitude ranges from 281.3 to 297.7. Median, lower and upper quartiles are used to specify variability, because they have the advantage of being less affected by large deviations that can occur during magnetic storms. The results show that the VTEC values corresponding to equinox are greater than those of solstice and that, the highest VTEC values are observed at low latitude stations. In general, the variability during daylight hours is about 30% of median or less, and that observed for nighttime hours is greater than the mentioned percentage, particularly at last hours of the night near the northern peak of the equatorial anomaly.

  15. VTEC behavior in the American sector during high solar activity

    International Nuclear Information System (INIS)

    Ezquer, R.G.; Brunini, C.; Meza, A.; Azpilicueta, F.; Mosert, M.; Radicella, S.M.

    2003-01-01

    The behavior of the vertical total electron content (VTEC) obtained from GPS signals received during the high solar activity year 1999 at stations placed in the American sector, is reported. The considered latitude range extends from 18.4 to -64.7 and the longitude ranges from 281.3 to 297.7. Median, lower and upper quartiles are used to specify variability, because they have the advantage of being less affected by large deviations that can occur during magnetic storms. The results show that the VTEC values corresponding to equinox are greater than those of solstice and that, the highest VTEC values are observed at low latitude stations. In general, the variability during daylight hours is about 30% of median or less, and that observed for nighttime hours is greater than the mentioned percentage, particularly at last hours of the night near the northern peak of the equatorial anomaly. (author)

  16. Thyroid storm precipitated by acute biliary pancreatitis

    Directory of Open Access Journals (Sweden)

    Mehrdad Karimi

    2017-01-01

    Full Text Available Thyroid storm is an acute, life-threatening exacerbation and sudden releasing large amounts of thyroid hormone in a short period of time. Nevertheless, critical aggravation of hyperthyroidism typically resulted from concurrent disorder. Synchronous management of thyroid storm along with its precipitant, such as infection is recommended. We described the case of an acute biliary pancreatitis complicated with a thyroid storm. The patient was successfully managed with a quick surgical intervention and further critical care for thyroid storm. Although it is widely believed that pancreatitis is seldom concurrent with thyrotoxicosis, thyroid storm can be precipitated by a variety of factors, including intra-abdominal infections such as acute pancreatitis or perforated peptic ulcer. In conclusion, acute pancreatitis in patients with thyrotoxicosis seems to be extremely rare, but such patients should be managed intensively against underlying thyroid disorders as well as pancreatitis.

  17. Effects of dust storm events on weekly clinic visits related to pulmonary tuberculosis disease in Minqin, China

    Science.gov (United States)

    Wang, Yun; Wang, Ruoyu; Ming, Jing; Liu, Guangxiu; Chen, Tuo; Liu, Xinfeng; Liu, Haixia; Zhen, Yunhe; Cheng, Guodong

    2016-02-01

    Pulmonary tuberculosis (PTB) is a major public health problem in China. Minqin, a Northwest county of China, has a very high number of annual PTB clinic visits and it is also known for its severe dust storms. The epidemic usually begins in February and ends in July, while the dust storms mainly occur throughout spring and early summer, thereby suggesting that there might be a close link between the causative agent of PTB and dust storms. We investigated the general impact of dust storms on PTB over time by analyzing the variation in weekly clinic visits in Minqin during 2005-2012. We used the Mann-Whitney-Pettitt test and a regression model to determine the seasonal periodicity of PTB and dust storms in a time series, as well as assessing the relationships between meteorological variables and weekly PTB clinic visits. After comparing the number of weekly PTB cases in Gansu province with dust storm events, we detected a clear link between the population dynamics of PTB and climate events, i.e., the onset of epidemics and dust storms (defined by an atmospheric index) occurred in almost the same mean week. Thus, particulate matter might be the cause of PTB outbreaks on dust storm days. It is highly likely that the significant decline in annual clinic visits was closely associated with improvements in the local environment, which prevented desertification and decreased the frequency of dust storm events. To the best of our knowledge, this is the first population-based study to provide clear evidence that a PTB epidemic was affected by dust storms in China, which may give insights into the association between this environmental problem and the evolution of epidemic disease.

  18. Study of characterizations of aerosols in a dust storm source region and its influence on Beijing by NAA and ICP-MS

    International Nuclear Information System (INIS)

    Song Yan; Chai Zhifang; Xu Diandou; Feng Weiyue; Ouyang Hong; Mao Xueying

    2005-01-01

    Dust storms have caused many problems in the environment, health and climate. For decades, dust storms have occurred frequently in various regions of China. The dust aerosols not only affected the local atmosphere, but also contaminated the atmosphere of the circumjacent regions. Further, they could affect Korea, Japan and even USA via long-range transportation. Many researches related to Chinese dust storms have been reported, however, there are few reports on the chemical components and characters of dust aerosols at their sources. Data on chemical properties of dust storm in the dust source region can help people understand the characteristics of dust storms and their influence on local and other regions. Duolun county (42 degree 13' N, 116 degree 25' E) lies in the southeast of Inner Mongolia, China, in the south of Hunshandake sands (one of the four famous sands in China). Because it is located at windward of Beijing, the dust aerosols can affect Beijing quickly when dust storm occurs. Hence, the study of chemical compositions and elemental abundance patterns of atmospheric particulate matters at Duolun is imperative to understand its influence on Beijing's atmospheric quality. In this work, TSP and PM2.5 samples were collected in Beijing and Duolun, Inner Mongolia, China, in April and May of 2002. Monthly arithmetic averages of the mass concentrations indicated that the pollution of atmospheric particulate matter's (APM) in Duolun was very serious, especially in April. The chemical compositions of total 163 samples were analyzed by INAA and ICP-MS and their origins were identified through Enrichment Factor and Principal Component Analysis. The results showed that the main source of Duolun aerosols was soil dust, and coal combustion constituted the important anthropogenic contribution. The dust events in April and changes of local meteorological conditions were the main reasons for the differences of APM characteristics between April and May. The

  19. Sensitivity study of surface wind flow of a limited area model simulating the extratropical storm Delta affecting the Canary Islands

    Directory of Open Access Journals (Sweden)

    C. Marrero

    2009-04-01

    Full Text Available In November 2005 an extratropical storm named Delta affected the Canary Islands (Spain. The high sustained wind and intense gusts experienced caused significant damage. A numerical sensitivity study of Delta was conducted using the Weather Research & Forecasting Model (WRF-ARW. A total of 27 simulations were performed. Non-hydrostatic and hydrostatic experiments were designed taking into account physical parameterizations and geometrical factors (size and position of the outer domain, definition or not of nested grids, horizontal resolution and number of vertical levels. The Factor Separation Method was applied in order to identify the major model sensitivity parameters under this unusual meteorological situation. Results associated to percentage changes relatives to a control run simulation demonstrated that boundary layer and surface layer schemes, horizontal resolutions, hydrostaticity option and nesting grid activation were the model configuration parameters with the greatest impact on the 48 h maximum 10 m horizontal wind speed solution.

  20. Observing Storm Surges from Space: A New Opportunity

    Science.gov (United States)

    Han, Guoqi; Ma, Zhimin; Chen, Dake; de Young, Brad; Chen, Nancy

    2013-04-01

    Coastal tide gauges can be used to monitor variations of a storm surge along the coast, but not in the cross-shelf direction. As a result, the cross-shelf structure of a storm surge has rarely been observed. In this study we focus on Hurricane Igor-induced storm surge off Newfoundland, Canada. Altimetric observations at about 2:30, September 22, 2010 UTC (hours after the passage of Hurricane Igor) reveal prominent cross-shelf variation of sea surface height during the storm passage, including a large nearshore slope and a mid-shelf depression. A significant coastal surge of 1 m derived from satellite altimetry is found to be consistent with tide-gauge measurements at nearby St. John's station. The post-storm sea level variations at St. John's and Argentia are argued to be associated with free equatorward-propagating continental shelf waves (with phase speeds of 11-13 m/s), generated along the northeast Newfoundland coast hours after the storm moved away from St. John's. The cross-shelf e-folding scale of the shelf wave was estimated to be ~100 km. We further show approximate agreement of altimetric and tide-gauge observations in the Gulf of Mexico during Hurricane Katrina (2005) and Isaac (2012). The study for the first time in the literature shows the robustness of satellite altimetry to observe storm surges, complementing tide-gauge observations for the analysis of storm surge characteristics and for the validation and improvement of storm surge models.

  1. Average features of cosmic ray variation associated with sudden commencement of magnetic storm

    International Nuclear Information System (INIS)

    Wada, Masami; Suda, Tomoshige.

    1980-01-01

    In order to obtain average features of cosmic ray variation associated with a passage of shock front in space, superposed epoch analysis of cosmic ray intensity with respect to the time of occurrence of sudden commencement (SC) of magnetic storm during solar cycle 20, 1964 - 1975, is carried out for hundreds of SC. When SC's are distributed evenly over the day, the onset in cosmic ray decrease is seen clearly within one hour of SC, followed by a sharp decrease in the intensity, but without any precursory fluctuation. The magnitude distribution and the rigidity spectrum for maximum depression show the features of Forbush decrease (FD). Superposed epoch analysis is also applied to solar wind and the interplanetary magnetic field data, and their relation to cosmic ray variation is studied. Effects of the superposition of the isotropic and anisotropic variations on the time profile of cosmic ray intensity observed at a station are discussed. (author)

  2. Enhanced poleward propagation of storms under climate change

    Science.gov (United States)

    Tamarin-Brodsky, Talia; Kaspi, Yohai

    2017-12-01

    Earth's midlatitudes are dominated by regions of large atmospheric weather variability—often referred to as storm tracks— which influence the distribution of temperature, precipitation and wind in the extratropics. Comprehensive climate models forced by increased greenhouse gas emissions suggest that under global warming the storm tracks shift poleward. While the poleward shift is a robust response across most models, there is currently no consensus on what the underlying dynamical mechanism is. Here we present a new perspective on the poleward shift, which is based on a Lagrangian view of the storm tracks. We show that in addition to a poleward shift in the genesis latitude of the storms, associated with the shift in baroclinicity, the latitudinal displacement of cyclonic storms increases under global warming. This is achieved by applying a storm-tracking algorithm to an ensemble of CMIP5 models. The increased latitudinal propagation in a warmer climate is shown to be a result of stronger upper-level winds and increased atmospheric water vapour. These changes in the propagation characteristics of the storms can have a significant impact on midlatitude climate.

  3. Influence of short-term solar disturbances on the fair weather conduction current

    Directory of Open Access Journals (Sweden)

    Elhalel Gal

    2014-01-01

    Full Text Available The fair weather atmospheric electrical current (Jz couples the ionosphere to the lower atmosphere and thus provides a route by which changes in solar activity can modify processes in the lower troposphere. This paper examines the temporal variations and spectral characteristics of continuous measurements of Jz conducted at the Wise Observatory in Mitzpe-Ramon, Israel (30°35′ N, 34°45′ E, during two large CMEs, and during periods of increased solar wind density. Evidence is presented for the effects of geomagnetic storms and sub-storms on low latitude Jz during two coronal mass ejections (CMEs, on 24–25th October 2011 and 7–8th March 2012, when the variability in Jz increased by an order of magnitude compared to normal fair weather conditions. The dynamic spectrum of the increased Jz fluctuations exhibit peaks in the Pc5 frequency range. Similar low frequency characteristics occur during periods of enhanced solar wind proton density. During the October 2011 event, the periods of increased fluctuations in Jz lasted for 7 h and coincided with fluctuations of the inter-planetary magnetic field (IMF detected by the ACE satellite. We suggest downward mapping of ionospheric electric fields as a possible mechanism for the increased fluctuations.

  4. What can the annual 10Be solar activity reconstructions tell us about historic space weather?

    Science.gov (United States)

    Barnard, Luke; McCracken, Ken G.; Owens, Mat J.; Lockwood, Mike

    2018-04-01

    Context: Cosmogenic isotopes provide useful estimates of past solar magnetic activity, constraining past space climate with reasonable uncertainty. Much less is known about past space weather conditions. Recent advances in the analysis of 10Be by McCracken & Beer (2015, Sol Phys 290: 305-3069) (MB15) suggest that annually resolved 10Be can be significantly affected by solar energetic particle (SEP) fluxes. This poses a problem, and presents an opportunity, as the accurate quantification of past solar magnetic activity requires the SEP effects to be determined and isolated, whilst doing so might provide a valuable record of past SEP fluxes. Aims: We compare the MB15 reconstruction of the heliospheric magnetic field (HMF), with two independent estimates of the HMF derived from sunspot records and geomagnetic variability. We aim to quantify the differences between the HMF reconstructions, and speculate on the origin of these differences. We test whether the differences between the reconstructions appear to depend on known significant space weather events. Methods: We analyse the distributions of the differences between the HMF reconstructions. We consider how the differences vary as a function of solar cycle phase, and, using a Kolmogorov-Smirnov test, we compare the distributions under the two conditions of whether or not large space weather events were known to have occurred. Results: We find that the MB15 reconstructions are generally marginally smaller in magnitude than the sunspot and geomagnetic HMF reconstructions. This bias varies as a function of solar cycle phase, and is largest in the declining phase of the solar cycle. We find that MB15's excision of the years with very large ground level enhancement (GLE) improves the agreement of the 10Be HMF estimate with the sunspot and geomagnetic reconstructions. We find no statistical evidence that GLEs, in general, affect the MB15 reconstruction, but this analysis is limited by having too few samples. We do find

  5. Solar activity impact on the Earth’s upper atmosphere

    Czech Academy of Sciences Publication Activity Database

    Kutiev, I.; Tsagouri, I.; Perrone, L.; Pancheva, D.; Mukhtarov, P.; Mikhailov, A.; Laštovička, Jan; Jakowski, N.; Burešová, Dalia; Blanch, E.; Andonov, B.; Altadill, D.; Magdaleno, S.; Parisi, M.; Torta, J. M.

    2013-01-01

    Roč. 3, February (2013), A06/1-A06/21 ISSN 2115-7251 Grant - others:COST(XE) ES0803 Institutional support: RVO:68378289 Keywords : ionosphere * solar activity * storm * total electron content * data analysis Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 2.519, year: 2013 http://www.swsc-journal.org/index.php?option=com_article&access=doi&doi=10.1051/swsc/2013028&Itemid=129

  6. The Storm Time Evolution of the Ionospheric Disturbance Plasma Drifts

    Science.gov (United States)

    Zhang, Ruilong; Liu, Libo; Le, Huijun; Chen, Yiding; Kuai, Jiawei

    2017-11-01

    In this paper, we use the C/NOFS and ROCSAT-1 satellites observations to analyze the storm time evolution of the disturbance plasma drifts in a 24 h local time scale during three magnetic storms driven by long-lasting southward IMF Bz. The disturbance plasma drifts during the three storms present some common features in the periods dominated by the disturbance dynamo. The newly formed disturbance plasma drifts are upward and westward at night, and downward and eastward during daytime. Further, the disturbance plasma drifts are gradually evolved to present significant local time shifts. The westward disturbance plasma drifts gradually migrate from nightside to dayside. Meanwhile, the dayside downward disturbance plasma drifts become enhanced and shift to later local time. The local time shifts in disturbance plasma drifts are suggested to be mainly attributed to the evolution of the disturbance winds. The strong disturbance winds arisen around midnight can constantly corotate to later local time. At dayside the westward and equatorward disturbance winds can drive the F region dynamo to produce the poleward and westward polarization electric fields (or the westward and downward disturbance drifts). The present results indicate that the disturbance winds corotated to later local time can affect the local time features of the disturbance dynamo electric field.

  7. Water quality of storm runoff and comparison of procedures for estimating storm-runoff loads, volume, event-mean concentrations, and the mean load for a storm for selected properties and constituents for Colorado Springs, southeastern Colorado, 1992

    Science.gov (United States)

    Von Guerard, Paul; Weiss, W.B.

    1995-01-01

    The U.S. Environmental Protection Agency requires that municipalities that have a population of 100,000 or greater obtain National Pollutant Discharge Elimination System permits to characterize the quality of their storm runoff. In 1992, the U.S. Geological Survey, in cooperation with the Colorado Springs City Engineering Division, began a study to characterize the water quality of storm runoff and to evaluate procedures for the estimation of storm-runoff loads, volume and event-mean concentrations for selected properties and constituents. Precipitation, streamflow, and water-quality data were collected during 1992 at five sites in Colorado Springs. Thirty-five samples were collected, seven at each of the five sites. At each site, three samples were collected for permitting purposes; two of the samples were collected during rainfall runoff, and one sample was collected during snowmelt runoff. Four additional samples were collected at each site to obtain a large enough sample size to estimate storm-runoff loads, volume, and event-mean concentrations for selected properties and constituents using linear-regression procedures developed using data from the Nationwide Urban Runoff Program (NURP). Storm-water samples were analyzed for as many as 186 properties and constituents. The constituents measured include total-recoverable metals, vola-tile-organic compounds, acid-base/neutral organic compounds, and pesticides. Storm runoff sampled had large concentrations of chemical oxygen demand and 5-day biochemical oxygen demand. Chemical oxygen demand ranged from 100 to 830 milligrams per liter, and 5.-day biochemical oxygen demand ranged from 14 to 260 milligrams per liter. Total-organic carbon concentrations ranged from 18 to 240 milligrams per liter. The total-recoverable metals lead and zinc had the largest concentrations of the total-recoverable metals analyzed. Concentrations of lead ranged from 23 to 350 micrograms per liter, and concentrations of zinc ranged from 110

  8. Ionospheric behaviour during storm recovery phase

    Science.gov (United States)

    Buresova, D.; Lastovicka, J.; Boska, J.; Sindelarova, T.; Chum, J.

    2012-04-01

    Intensive ionospheric research, numerous multi-instrumental observations and large-scale numerical simulations of ionospheric F region response to magnetic storm-induced disturbances during the last several decades were primarily focused on the storm main phase, in most cases covering only a few hours of the recovery phase following after storm culmination. Ionospheric behaviour during entire recovery phase still belongs to not sufficiently explored and hardly predictable features. In general, the recovery phase is characterized by an abatement of perturbations and a gradual return to the "ground state" of ionosphere. However, observations of stormy ionosphere show significant departures from the climatology also within this phase. This paper deals with the quantitative and qualitative analysis of the ionospheric behaviour during the entire recovery phase of strong-to-severe magnetic storms at middle latitudes for nowadays and future modelling and forecasting purposes.

  9. Storm and cloud dynamics

    CERN Document Server

    Cotton, William R

    1992-01-01

    This book focuses on the dynamics of clouds and of precipitating mesoscale meteorological systems. Clouds and precipitating mesoscale systems represent some of the most important and scientifically exciting weather systems in the world. These are the systems that produce torrential rains, severe winds including downburst and tornadoes, hail, thunder and lightning, and major snow storms. Forecasting such storms represents a major challenge since they are too small to be adequately resolved by conventional observing networks and numerical prediction models.Key Features* Key Highlight

  10. Storm surge climatology report

    OpenAIRE

    Horsburgh, Kevin; Williams, Joanne; Cussack, Caroline

    2017-01-01

    Any increase in flood frequency or severity due to sea level rise or changes in storminess would adversely impact society. It is crucial to understand the physical drivers of extreme storm surges to have confidence in the datasets used for extreme sea level statistics. We will refine and improve methods to the estimation of extreme sea levels around Europe and more widely. We will do so by developing a comprehensive world picture of storm surge distribution (including extremes) for both tropi...

  11. Alternative salvage technique during postcardiotomy electrical storm.

    Science.gov (United States)

    Ryu, Y G; Baek, M J; Kim, H J

    2010-08-01

    Cardiac electrical storm is generally treated with antiarrhythmic drugs, electrical cardioversion, or catheter ablation. However, these conservative treatment modalities are considered neither curative nor preventive with regard to recurrent arrhythmias in postoperative electrical storm after open heart surgery. We present a case of surgical ventricular assist device placement for postcardiotomy electrical storm in a 38-year-old patient. Copyright (c) Georg Thieme Verlag KG Stuttgart-New York.

  12. Parameters affecting the performance of a low cost solar still

    International Nuclear Information System (INIS)

    Ahsan, A.; Imteaz, M.; Thomas, U.A.; Azmi, M.; Rahman, A.; Nik Daud, N.N.

    2014-01-01

    Highlights: • The triangular solar still is designed using cheap and durable materials. • The initial water depth has an inverse relationship with the production. • The water productivity is nearly proportional to the solar radiation. • The water quality parameters are within the accepted ranges of drinking water. - Abstract: This study aims at developing a low cost technique to be used in rural and coastal areas for converting saline water into potable water using solar energy. A triangular solar still (TrSS) was, therefore, designed and developed with cheap, lightweight, local and available materials. A number of field experiments were carried out to evaluate the effects of solar radiation intensity, ambient air temperature and the initial water depth on the daily water production of the TrSS. A time lag of about and hour between the hourly peaks of solar radiation and water production is observed. Finally, a few essential relationships were attained, e.g. between the daily production and the initial water depth, between the daily production and daily solar radiation, and between the daily production and the average ambient temperature. The effect of the initial water depth in the basin on the daily water productivity was evaluated by varying the water depths (1.5, 2.5 and 5 cm) with the climatic condition of Malaysia and an inverse proportional relationship was revealed between them. However, the daily water productivity is nearly proportional to the daily solar radiation. In addition, some important water quality parameters were tested in the laboratory to evaluate the distillate quality and were then compared with the drinking water standards

  13. Earth-Affecting Solar Causes Observatory (EASCO): a mission at the Sun-Earth L5

    DEFF Research Database (Denmark)

    Gopalswamy, Nat; Davila, Joseph M.; Auchère, Frédéric

    2011-01-01

    Observatory (STEREO) missions, but these missions lacked some key measurements: STEREO did not have a magnetograph; SOHO did not have in-situ magnetometer. SOHO and other imagers such as the Solar Mass Ejection Imager (SMEI) located on the Sun-Earth line are also not well-suited to measure Earth-directed CMEs....... The Earth-Affecting Solar Causes Observatory (EASCO) is a proposed mission to be located at the Sun-Earth L5 that overcomes these deficiencies. The mission concept was recently studied at the Mission Design Laboratory (MDL), NASA Goddard Space Flight Center, to see how the mission can be implemented....... The study found that the scientific payload (seven remote-sensing and three in-situ instruments) can be readily accommodated and can be launched using an intermediate size vehicle; a hybrid propulsion system consisting of a Xenon ion thruster and hydrazine has been found to be adequate to place the payload...

  14. Regional Climate Impacts of Stabilizing Global Warming at 1.5 K Using Solar Geoengineering

    Science.gov (United States)

    Jones, Anthony C.; Hawcroft, Matthew K.; Haywood, James M.; Jones, Andy; Guo, Xiaoran; Moore, John C.

    2018-02-01

    The 2015 Paris Agreement aims to limit global warming to well below 2 K above preindustrial levels, and to pursue efforts to limit global warming to 1.5 K, in order to avert dangerous climate change. However, current greenhouse gas emissions targets are more compatible with scenarios exhibiting end-of-century global warming of 2.6-3.1 K, in clear contradiction to the 1.5 K target. In this study, we use a global climate model to investigate the climatic impacts of using solar geoengineering by stratospheric aerosol injection to stabilize global-mean temperature at 1.5 K for the duration of the 21st century against three scenarios spanning the range of plausible greenhouse gas mitigation pathways (RCP2.6, RCP4.5, and RCP8.5). In addition to stabilizing global mean temperature and offsetting both Arctic sea-ice loss and thermosteric sea-level rise, we find that solar geoengineering could effectively counteract enhancements to the frequency of extreme storms in the North Atlantic and heatwaves in Europe, but would be less effective at counteracting hydrological changes in the Amazon basin and North Atlantic storm track displacement. In summary, solar geoengineering may reduce global mean impacts but is an imperfect solution at the regional level, where the effects of climate change are experienced. Our results should galvanize research into the regionality of climate responses to solar geoengineering.

  15. nuSTORM Costing document

    Energy Technology Data Exchange (ETDEWEB)

    Bross, Alan D. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2013-10-01

    Detailed costing of the nuSTORM conventional facilities has been done by the Fermilab Facilities Engineering Services Section (FESS) and is reported on in the nuSTORM Project Definition Report (PDR) 6-13-1. Estimates for outfitting the primary proton beam line, the target station, the pion capture/transport line and decay ring are based on either experience from existing Fermilab infrastructure (NuMI) or is based on the detailed costing exercises for DOE CD-1 approval for future experiments (mu2e and LBNE). The detector costing utilized the Euronu costing for the Neutrino Factory Magnetized Iron Neutrino Detector (MIND), extrapolations from MINOS as-built costs and from recent vendor quotes. Costs included all manpower and are fully burdened (FY2013 dollars). The costs are not escalated, however, beyond the 5-year project timeline, since a project start for nuSTORM is unknown. Escalation can be estimated from various models (see Figure 1). LBNE has used the Jacob’s model to determine their cost escalation.

  16. Analysis of the environments of seven Mediterranean tropical-like storms using an axisymmetric, nonhydrostatic, cloud resolving model

    Directory of Open Access Journals (Sweden)

    L. Fita

    2007-01-01

    Full Text Available Tropical-like storms on the Mediterranean Sea are occasionally observed on satellite images, often with a clear eye surrounded by an axysimmetric cloud structure. These storms sometimes attain hurricane intensity and can severely affect coastal lands. A deep, cut-off, cold-core low is usually observed at mid-upper tropospheric levels in association with the development of these tropical-like systems. In this study we attempt to apply some tools previously used in studies of tropical hurricanes to characterise the environments in which seven known Mediterranean events developed. In particular, an axisymmetric, nonhydrostatic, cloud resolving model is applied to simulate the tropical-like storm genesis and evolution. Results are compared to surface observations when landfall occurred and with satellite microwave derived wind speed measurements over the sea. Finally, sensitivities of the numerical simulations to different factors (e.g. sea surface temperature, vertical humidity profile and size of the initial precursor of the storm are examined.

  17. Multi-Instrument Observations of a Geomagnetic Storm and its Effects on the Arctic Ionosphere: A Case Study of the 19 February 2014 Storm

    DEFF Research Database (Denmark)

    Durgonics, Tibor; Komjathy, Attila; Verkhoglyadova, Olga

    2017-01-01

    We present a multi-instrumented approach for the analysis of the Arctic ionosphere during the 19 February 2014 highly complex, multiphase geomagnetic storm, which had the largest impact on the disturbance storm-time (Dst) index that year. The geomagnetic storm was the result of two powerful Earth......-directed coronal mass ejections (CMEs). It produced a strong long lasting negative storm phase over Greenland with a dominant energy input in the polar-cap. We employed GNSS networks, geomagnetic observatories, and a specific ionosonde station in Greenland. We complemented the approach with spaceborne measurements...... specifically found that, (1) Thermospheric O/N2 measurements demonstrated significantly lower values over the Greenland sector than prior to the storm-time. (2) An increased ion flow in the topside ionosphere was observed during the negative storm phase. (3) Negative storm phase was a direct consequence...

  18. Storm/substorm signatures in the outer belt

    International Nuclear Information System (INIS)

    Korth, A.; Friedel, R.H.W.; Mouikis, C.; Fennell, J.F.

    1998-01-01

    The response of the ring current region is compared for periods of storm and substorm activity, with an attempt to isolate the contributions of both processes. The authors investigate CRRES particle data in an overview format that allows the display of long-term variations of the outer radiation belt. They compare the evolution of the ring current population to indicators of storm (Dst) and substorm (AE) activity and examine compositional changes. Substorm activity leads to the intensification of the ring current at higher L (L ∼ 6) and lower ring current energies compared to storms (L ∼ 4). The O + /H + ratio during substorms remains low, near 10%, but is much enhanced during storms (can exceed 100%). They conclude that repeated substorms with an AE ∼ 900 nT lead to a ΔDst of ∼ 30 nT, but do not contribute to Dst during storm main phase as substorm injections do not form a symmetric ring current during such disturbed times

  19. From the Sun to the Earth: impact of the 27-28 May 2003 solar events on the magnetosphere, ionosphere and thermosphere

    Directory of Open Access Journals (Sweden)

    C. Hanuise

    2006-03-01

    Full Text Available During the last week of May 2003, the solar active region AR 10365 produced a large number of flares, several of which were accompanied by Coronal Mass Ejections (CME. Specifically on 27 and 28 May three halo CMEs were observed which had a significant impact on geospace. On 29 May, upon their arrival at the L1 point, in front of the Earth's magnetosphere, two interplanetary shocks and two additional solar wind pressure pulses were recorded by the ACE spacecraft. The interplanetary magnetic field data showed the clear signature of a magnetic cloud passing ACE. In the wake of the successive increases in solar wind pressure, the magnetosphere became strongly compressed and the sub-solar magnetopause moved inside five Earth radii. At low altitudes the increased energy input to the magnetosphere was responsible for a substantial enhancement of Region-1 field-aligned currents. The ionospheric Hall currents also intensified and the entire high-latitude current system moved equatorward by about 10°. Several substorms occurred during this period, some of them - but not all - apparently triggered by the solar wind pressure pulses. The storm's most notable consequences on geospace, including space weather effects, were (1 the expansion of the auroral oval, and aurorae seen at mid latitudes, (2 the significant modification of the total electron content in the sunlight high-latitude ionosphere, (3 the perturbation of radio-wave propagation manifested by HF blackouts and increased GPS signal scintillation, and (4 the heating of the thermosphere, causing increased satellite drag. We discuss the reasons why the May 2003 storm is less intense than the October-November 2003 storms, although several indicators reach similar intensities.

  20. Coastal Storm Hazards from Virginia to Maine

    Science.gov (United States)

    2015-11-01

    secondary terms • integration of joint probability of storm responses, including extratropical events. A diagram summarizing the JPM methodology is... Extratropical Cyclones. The GPD- based approach defined above was used to compute the final storm response statistics for XCs. ERDC/CHL TR-15-5 39...from the numerical modeling of all storms , tropical and extratropical . As discussed in Section 2.1.2, JPM methodology generally consists of the