WorldWideScience

Sample records for dust storm forecasting

  1. Trajectory Calculation as Forecasting Support Tool for Dust Storms

    Directory of Open Access Journals (Sweden)

    Sultan Al-Yahyai

    2014-01-01

    Full Text Available In arid and semiarid regions, dust storms are common during windy seasons. Strong wind can blow loose sand from the dry surface. The rising sand and dust is then transported to other places depending on the wind conditions (speed and direction at different levels of the atmosphere. Considering dust as a moving object in space and time, trajectory calculation then can be used to determine the path it will follow. Trajectory calculation is used as a forecast supporting tool for both operational and research activities. Predefined dust sources can be identified and the trajectories can be precalculated from the Numerical Weather Prediction (NWP forecast. In case of long distance transported dust, the tool should allow the operational forecaster to perform online trajectory calculation. This paper presents a case study for using trajectory calculation based on NWP models as a forecast supporting tool in Oman Meteorological Service during some dust storm events. Case study validation results showed a good agreement between the calculated trajectories and the real transport path of the dust storms and hence trajectory calculation can be used at operational centers for warning purposes.

  2. Dust storm events over Delhi: verification of dust AOD forecasts with satellite and surface observations

    Science.gov (United States)

    Singh, Aditi; Iyengar, Gopal R.; George, John P.

    2016-05-01

    Thar desert located in northwest part of India is considered as one of the major dust source. Dust storms originate in Thar desert during pre-monsoon season, affects large part of Indo-Gangetic plains. High dust loading causes the deterioration of the ambient air quality and degradation in visibility. Present study focuses on the identification of dust events and verification of the forecast of dust events over Delhi and western part of IG Plains, during the pre-monsoon season of 2015. Three dust events have been identified over Delhi during the study period. For all the selected days, Terra-MODIS AOD at 550 nm are found close to 1.0, while AURA-OMI AI shows high values. Dust AOD forecasts from NCMRWF Unified Model (NCUM) for the three selected dust events are verified against satellite (MODIS) and ground based observations (AERONET). Comparison of observed AODs at 550 nm from MODIS with NCUM predicted AODs reveals that NCUM is able to predict the spatial and temporal distribution of dust AOD, in these cases. Good correlation (~0.67) is obtained between the NCUM predicted dust AODs and location specific observations available from AERONET. Model under-predicted the AODs as compared to the AERONET observations. This may be mainly because the model account for only dust and no anthropogenic activities are considered. The results of the present study emphasize the requirement of more realistic representation of local dust emission in the model both of natural and anthropogenic origin, to improve the forecast of dust from NCUM during the dust events.

  3. Sand-Dust Storm Ensemble Forecast Model Based on Rough Set

    Institute of Scientific and Technical Information of China (English)

    LU Zhiying; YANG Le; LI Yanying; ZHAO Zhichao

    2007-01-01

    To improve the accuracy of sand-dust storm forecast system, a sand-dust storm ensemble forecast model based on rough set (RS) is proposed. The feature data are extracted from the historical data sets using the self-organization map (SOM) clustering network and single fields forecast to form the feature values with low dimensions. Then, the unwanted attributes are reduced according to RS to discretize the continuous feature values. Lastly, the minimum decision rules are constructed according to the remainder attributes, namely sand-dust storm ensemble forecast model based on RS is constructed. Results comparison between the proposed model and the back propagation neural network model show that the sand-storm forecast model based on RS has better stability, faster running speed, and its forecasting accuracy ratio is increased from 17.1% to 86.21%.

  4. An air quality forecasting system in Beijing - Application to the study of dust storm events in China in May 2008

    Institute of Scientific and Technical Information of China (English)

    Qijie Zhang; Benoit Laurent; Fanny Velay-Lasry; Richard Ngo; Claude Derognat; Béatrice Marticorena; Armand Albergel

    2012-01-01

    An air pollution forecast system,ARIA Regional,was implemented in 2007-2008 at the Beijing Municipality Environmental Monitoring Center,providing daily forecast of main pollutant concentrations.The chemistry-transport model CHIMERE was coupled with the dust emission model MB95 for restituting dust storm events in springtime so as to improve forecast results.Dust storm events were sporadic but could be extremely intense and then control air quality indexes close to the source areas but also far in the Beijing area.A dust episode having occurred at the end of May 2008 was analyzed in this article,and its impact of particulate matter on the Chinese air pollution index (API) was evaluated.Following our estimation,about 23 Tg of dust were emitted from source areas in Mongolia and in the Inner Mongolia of China,transporting towards southeast.This episode of dust storm influenced a large part of North China and East China,and also South Korea.The model result was then evaluated using satellite observations and in situ data.The simulated daily concentrations of total suspended particulate at 6:00 UTC had a similar spatial pattern with respect to OMI satellite aerosol index.Temporal evolution of dust plume was evaluated by comparing dust aerosol optical depth (AOD) calculated from the simulations with AOD derived from MODIS satellite products.Finally,the comparison of reported Chinese API in Beijing with API calculated from the simulation including dust emissions had showed the significant improvement of the model results taking into account mineral dust correctly.

  5. A Stormy Forecast for the Upcoming Dust Storm Season on Mars

    Science.gov (United States)

    Shirley, J. H.; Mischna, M. A.

    2015-12-01

    The dust storm season on Mars is centered on the time of Mars' perihelion, which occurs late in the southern spring. The dust storm season of the current Mars year (MY 33) will begin on 1 June 2016 (Ls=160°) and will end on 28 March 2017 (Ls=340°). Mars will reach perihelion in late October 2016, about a month after the planned landing of the Mars InSight Lander. Spectacular global-scale dust storms (GDS) occur during the dust storm season in some Mars years but not in others. In a prior study (Shirley, 2015; Icarus 251, 128-144), systematic relationships were found linking the occurrence of historic global-scale dust storms on Mars with the variability of the orbital angular momentum of the planet with respect to the solar system barycenter. Conditions favorable to the occurrence of a future GDS in the current Mars year were noted in that study. A physical model that may account for the observed relationships has subsequently emerged. In this model, a weak coupling of the orbital and rotational motions of extended bodies is effected through a modulation of circulatory flows of atmospheres. The formal derivation yields a coupling term, which in turn prescribes an acceleration field that may constructively or destructively interfere with large-scale atmospheric motions driven by other means. This coupling term has been incorporated within the MarsWRF Global Circulation Model, and the GCM thus modified has undergone extensive validation and testing. The GCM "retrodicts" accelerations and circulation patterns favorable for the occurrence of southern summer solstice season global-scale dust storms in all of the prior years (n=7) in which such storms are known to have occurred (Mischna and Shirley, this meeting). The forcing function for the upcoming dust storm season exhibits amplitude and phasing that largely replicates the dynamical conditions prevailing prior to and during the MY 9 GDS of 1971. We conclude that a global-scale dust storm is likely to occur during

  6. Team for Research on Formation and Development Mechanisms of Asian Dust Storm and Its Monitoring, Forecast and Disaster Assessment

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    In cooperation with experts from the China Meteorological Administration, the research team at the CAS Institute of Atmospheric Physics (IAP) has been focusing on soil erosion and the formation and evolution mechanisms of dust storms. Over the past ten years, the involved scientists systematically investigated the life cycle of dust storms, including the tbrmation mechanism,

  7. Simulating the meteorology and PM10 concentrations in Arizona dust storms with the Weather Research and Forecasting model with Chemistry (Wrf-Chem).

    Science.gov (United States)

    Hyde, Peter; Mahalov, Alex; Li, Jialun

    2017-07-24

    Nine dust storms in south-central Arizona, USA were simulated with the Weather Research and Forecasting with Chemistry model (WRF-Chem) at 2-km resolution. The windblown dust emission algorithm was the Air Force Weather Agency model. In comparison with ground-based PM10 observations, the model unevenly reproduces the dust storm events. The model adequately estimates the location and timing of the events, but it is unable to precisely replicate the magnitude and timing of the elevated hourly concentrations of particles 10 microns and smaller ([PM10]).Furthermore, the model under-estimated [PM10] in highly agricultural Pinal County because it under-estimated surface wind speeds and because the model's erodible fractions of the land surface data were too coarse to effectively resolve the active and abandoned agricultural lands. In contrast, the model over-estimated [PM10] in western Arizona along the Colorado River because it generated daytime sea breezes (from the nearby Gulf of California) whose surface-layer speeds were too strong. In Phoenix the model's performance depended on the event, with both under- and over-estimations partly due to incorrect representation of urban features. Sensitivity tests indicate that [PM10] highly rely on meteorological forcing. Increasing the fraction of erodible surfaces in the Pinal County agricultural areas improved the simulation of [PM10] in that region. Both 24-hr and 1-hr measured [PM10] were, for the most part, and especially in Pinal County, extremely elevated, with the former exceeding the health standard by as much as tenfold and the latter exceeding health-based guidelines by as much as seventy-fold. Monsoonal thunderstorms not only produce elevated [PM10], but also cause flash floods and disrupt water resource deliveries. Given the severity and frequency of these dust storms, and conceding that the modeling system applied in this work did not produce the desired agreement between simulations and observations, additional

  8. Clouds and Dust Storms

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Released 2 July 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth. Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms. This image was acquired during mid-spring near the North Pole. The linear water-ice clouds are now regional in extent and often interact with neighboring cloud system, as seen in this image. The bottom of the image shows how the interaction can destroy the linear nature. While the surface is still visible through most of the clouds, there is evidence that dust is also starting to enter the atmosphere. Image information: VIS instrument. Latitude 68.4, Longitude 180 East (180 West). 38 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote

  9. Operational retrieval of Asian sand and dust storm from FY-2C geostationary meteorological satellite and its application to real time forecast in Asia

    Directory of Open Access Journals (Sweden)

    T. Niu

    2008-03-01

    Full Text Available This paper describes an operational retrieval algorithm for the sand/dust storm (SDS from FY-2C/S-VISSR (Stretched-Visible and Infrared Spin-Scan Radiometer developed at the National Satellite Meteorological Center (NSMC of China. This algorithm, called Dust Retrieval Algorithm based on Geostationary Imager (DRAGI, is based on the optical and radiative physical properties of SDS in mid-infrared and thermal infrared spectral regions as well as the observation of all bands in the geostationary imager, which include the Brightness Temperature Difference (BTD in split window channels, Infrared Difference Dust Index (IDDI and the ratio of middle infrared reflectance to visible reflectance. It also combines the visible and water vapor bands observation of the geostationary imager to identify the dust clouds from the surface targets and meteorological clouds. The output product is validated by and related to other dust aerosol observations such as the synoptic weather reports, surface visibility, aerosol optical depth (AOD and ground-based PM10 observations. Using the SDS-IDD product and a data assimilation scheme, the dust forecast model CUACE/Dust achieved a substantial improvement to the SDS predictions in spring 2006.

  10. Dust Storms: Why Are Dust Storms a Concern?

    Science.gov (United States)

    ... Radon Solvents Styrene Sulfur Dioxide Toluene Uranium Volatile Organic Compounds (VOCs) For Educators Introduction Tox Town-Based Curriculum Units / Science Club Careers in Environmental Health, Chemistry, and Toxicology More Resources Dust Storms en español ...

  11. Climate, not conflict, explains extreme Middle East dust storm

    Science.gov (United States)

    Parolari, Anthony J.; Li, Dan; Bou-Zeid, Elie; Katul, Gabriel G.; Assouline, Shmuel

    2016-11-01

    The recent dust storm in the Middle East (Sepember 2015) was publicized in the media as a sign of an impending ‘Dust Bowl.’ Its severity, demonstrated by extreme aerosol optical depth in the atmosphere in the 99th percentile compared to historical data, was attributed to the ongoing regional conflict. However, surface meteorological and remote sensing data, as well as regional climate model simulations, support an alternative hypothesis: the historically unprecedented aridity played a more prominent role, as evidenced by unusual climatic and meteorological conditions prior to and during the storm. Remotely sensed normalized difference vegetation index demonstrates that vegetation cover was high in 2015 relative to the prior drought and conflict periods, suggesting that agricultural activity was not diminished during that year, thus negating the media narrative. Instead, meteorological simulations using the Weather Research and Forecasting (WRF) model show that the storm was associated with a cyclone and ‘Shamal’ winds, typical for dust storm generation in this region, that were immediately followed by an unusual wind reversal at low levels that spread dust west to the Mediterranean Coast. These unusual meteorological conditions were aided by a significant reduction in the critical shear stress due to extreme dry and hot conditions, thereby enhancing dust availability for erosion during this storm. Concluding, unusual aridity, combined with unique synoptic weather patterns, enhanced dust emission and westward long-range transport across the region, thus generating the extreme storm.

  12. Clearing the Martian air - The troubled history of dust storms

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    Martin, L. J.

    1984-03-01

    This note is an attempt to resolve some misconceptions regarding the historical record of the Martian atmospheric phenomena referred to as 'dust storms,' but often called yellow storms, yellow clouds, planetwide dust storms, global dust storms, great dust storms, etc. The known frequency of planet-encircling storms will be specifically addressed. Better knowledge of the sizes, frequencies, and locations of Martian dust storms is needed for atmospheric modeling and for future mission planning.

  13. The Barcelona Dust Forecast Center: The first WMO regional meteorological center specialized on atmospheric sand and dust forecast

    Science.gov (United States)

    Basart, Sara; Terradellas, Enric; Cuevas, Emilio; Jorba, Oriol; Benincasa, Francesco; Baldasano, Jose M.

    2015-04-01

    The World Meteorological Organization's Sand and Dust Storm Warning Advisory and Assessment System (WMO SDS-WAS, http://sds-was.aemet.es/) project has the mission to enhance the ability of countries to deliver timely and quality sand and dust storm forecasts, observations, information and knowledge to users through an international partnership of research and operational communities. The good results obtained by the SDS-WAS Northern Africa, Middle East and Europe (NAMEE) Regional Center and the demand of many national meteorological services led to the deployment of operational dust forecast services. On June 2014, the first WMO Regional Meteorological Center Specialized on Atmospheric Sand and Dust Forecast, the Barcelona Dust Forecast Center (BDFC; http://dust.aemet.es/), was publicly presented. The Center operationally generates and distributes predictions for the NAMEE region. The dust forecasts are based on the NMMB/BSC-Dust model developed at the Barcelona Supercomputing Center (BSC-CNS). The present contribution will describe the main objectives and capabilities of BDFC. One of the activities performed by the BDFC is to establish a protocol to routinely exchange products from dust forecast models as dust load, dust optical depth (AOD), surface concentration, surface extinction and deposition. An important step in dust forecasting is the evaluation of the results that have been generated. This process consists of the comparison of the model results with multiple kinds of observations (i.e. AERONET and MODIS) and is aimed to facilitate the understanding of the model capabilities, limitations, and appropriateness for the purpose for which it was designed. The aim of this work is to present different evaluation approaches and to test the use of different observational products in the evaluation system.

  14. Distribution of dust during two dust storms in Iceland

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    Ösp Magnúsdóttir, Agnes; Dagsson-Waldhauserova, Pavla; Arnalds, Ólafur; Ólafsson, Haraldur

    2017-04-01

    Particulate matter mass concentrations and size fractions of PM1, PM2.5, PM4, PM10, and PM15 measured in transversal horizontal profile of two dust storms in southwestern Iceland are presented. Images from a camera network were used to estimate the visibility and spatial extent of measured dust events. Numerical simulations were used to calculate the total dust flux from the sources as 180,000 and 280,000 tons for each storm. The mean PM15 concentrations inside of the dust plumes varied from 10 to 1600 ?g?m?3 (PM10 = 7 to 583 ?g?m?3). The mean PM1 concentrations were 97-241 ?g?m?3 with a maximum of 261 ?g?m?3 for the first storm. The PM1/PM2.5 ratios of >0.9 and PM1/PM10 ratios of 0.34-0.63 show that suspension of volcanic materials in Iceland causes air pollution with extremely high PM1 concentrations, similar to polluted urban areas in Europe or Asia. Icelandic volcanic dust consists of a higher proportion of submicron particles compared to crustal dust. Both dust storms occurred in relatively densely inhabited areas of Iceland. First results on size partitioning of Icelandic dust presented here should challenge health authorities to enhance research in relation to dust and shows the need for public dust warning systems.

  15. Reduced Baroclinicity During Martian Global Dust Storms

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    Battalio, Joseph; Szunyogh, Istvan; Lemmon, Mark

    2015-11-01

    The eddy kinetic energy equation is applied to the Mars Analysis Correction Data Assimilation (MACDA) dataset during the pre-winter solstice period for the northern hemisphere of Mars. Traveling waves are triggered by geopotential flux convergence, grow baroclinically, and decay barotropically. Higher optical depth increases the static stability, which reduces vertical and meridional heat fluxes. Traveling waves during a global dust storm year develop a mixed baroclinic/barotropic growth phase before decaying barotropically. Baroclinic energy conversion is reduced during the global dust storm, but eddy intensity is undiminished. Instead, the frequency of storms is reduced due to a stabilized vertical profile.

  16. CRADE OF SAND AND DUST STORM WEATHER

    Institute of Scientific and Technical Information of China (English)

    Niu Ruoyun; Tian Cuiying; Bi Baogui; Yang Keming; Wang Youheng; Tuo Ya; Ding Haifang; Zhang Tairen

    2011-01-01

    Background Sand and dust storm,as one of the main disastrous weathers that affect northern China,not only affect the people health and normal life,but cause the short-term climatic changes due to the direct and indirect radiation of the earth-atmosphere system through the dust floating in the sky.The sand end dust weather and its potential harm on the national economy,ecological environment,social activities and other aspects have aroused worldwide concern.

  17. Automated dust storm detection using satellite images. Development of a computer system for the detection of dust storms from MODIS satellite images and the creation of a new dust storm database

    Science.gov (United States)

    El-Ossta, Esam Elmehde Amar

    Dust storms are one of the natural hazards, which have increased in frequency in the recent years over Sahara desert, Australia, the Arabian Desert, Turkmenistan and northern China, which have worsened during the last decade. Dust storms increase air pollution, impact on urban areas and farms as well as affecting ground and air traffic. They cause damage to human health, reduce the temperature, cause damage to communication facilities, reduce visibility which delays both road and air traffic and impact on both urban and rural areas. Thus, it is important to know the causation, movement and radiation effects of dust storms. The monitoring and forecasting of dust storms is increasing in order to help governments reduce the negative impact of these storms. Satellite remote sensing is the most common method but its use over sandy ground is still limited as the two share similar characteristics. However, satellite remote sensing using true-colour images or estimates of aerosol optical thickness (AOT) and algorithms such as the deep blue algorithm have limitations for identifying dust storms. Many researchers have studied the detection of dust storms during daytime in a number of different regions of the world including China, Australia, America, and North Africa using a variety of satellite data but fewer studies have focused on detecting dust storms at night. The key elements of this present study are to use data from the Moderate Resolution Imaging Spectroradiometers on the Terra and Aqua satellites to develop more effective automated method for detecting dust storms during both day and night and generate a MODIS dust storm database..

  18. Dust Storm Moving Near Phoenix Lander

    Science.gov (United States)

    2008-01-01

    This series of images show the movement of several dust storms near NASA's Phoenix Mars Lander. These images were taken by the lander's Surface Stereo Imager (SSI) on the 137th Martian day, or sol, of the mission (Oct. 13, 2008). These images were taken about 50 seconds apart, showing the formation and movement of dust storms for nearly an hour. Phoenix scientists are still figuring out the exact distances these dust storms occurred from the lander, but they estimate them to be about 1 to 2 kilometers (.6 or 1.2 miles) away. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  19. Principles of major geomagnetic storms forecasting

    Science.gov (United States)

    Zagnetko, Alexander; Applbaum, David; Dorman, Lev; Pustil'Nik, Lev; Sternlieb, Abraham; Zukerman, Igor

    According to NOAA Space Weather Scales, geomagnetic storms of scales G5 (3-hour index of geomagnetic activity Kp=9), G4 (Kp=8) and G3 (Kp=7) are dangerous for people technology and health (influence on power systems, on spacecraft operations, on HF radio-communications and others). To prevent these serious damages will be very important to forecast dangerous geomagnetic storms. In many papers it was shown that in principle for this forecasting can be used data on CR intensity and CR anisotropy changing before SC of major geomagnetic storms accompanied by sufficient Forbush-decreases (e.g., Dorman et al., 1995, 1999). In this paper we consider all types of observed precursor effects in CR what can be used for forecasting of great geomagnetic storms and possible mechanisms of these precursor effects origin. REFERENCES: Dorman L.I., et al. "Cosmic-ray forecasting features for big Forbush-decreases". Nuclear Physics B, 49A, 136-144 (1995). L.I.Dorman, et al, "Cosmic ray Forbush-decrease as indicators of space dangerous phenomenon and possible use of cosmic ray data for their pre-diction", Proc. of 26-th Intern. Cosmic Ray Conference, Salt Lake City, 6, 476-479 (1999).

  20. Ionospheric data assimilation and forecasting during storms

    Science.gov (United States)

    Chartier, Alex T.; Matsuo, Tomoko; Anderson, Jeffrey L.; Collins, Nancy; Hoar, Timothy J.; Lu, Gang; Mitchell, Cathryn N.; Coster, Anthea J.; Paxton, Larry J.; Bust, Gary S.

    2016-01-01

    Ionospheric storms can have important effects on radio communications and navigation systems. Storm time ionospheric predictions have the potential to form part of effective mitigation strategies to these problems. Ionospheric storms are caused by strong forcing from the solar wind. Electron density enhancements are driven by penetration electric fields, as well as by thermosphere-ionosphere behavior including Traveling Atmospheric Disturbances and Traveling Ionospheric Disturbances and changes to the neutral composition. This study assesses the effect on 1 h predictions of specifying initial ionospheric and thermospheric conditions using total electron content (TEC) observations under a fixed set of solar and high-latitude drivers. Prediction performance is assessed against TEC observations, incoherent scatter radar, and in situ electron density observations. Corotated TEC data provide a benchmark of forecast accuracy. The primary case study is the storm of 10 September 2005, while the anomalous storm of 21 January 2005 provides a secondary comparison. The study uses an ensemble Kalman filter constructed with the Data Assimilation Research Testbed and the Thermosphere Ionosphere Electrodynamics General Circulation Model. Maps of preprocessed, verticalized GPS TEC are assimilated, while high-latitude specifications from the Assimilative Mapping of Ionospheric Electrodynamics and solar flux observations from the Solar Extreme Ultraviolet Experiment are used to drive the model. The filter adjusts ionospheric and thermospheric parameters, making use of time-evolving covariance estimates. The approach is effective in correcting model biases but does not capture all the behavior of the storms. In particular, a ridge-like enhancement over the continental USA is not predicted, indicating the importance of predicting storm time electric field behavior to the problem of ionospheric forecasting.

  1. Data assimilation of dust aerosol observations for the CUACE/dust forecasting system

    Directory of Open Access Journals (Sweden)

    T. Niu

    2008-07-01

    Full Text Available A data assimilation system (DAS was developed for the Chinese Unified Atmospheric Chemistry Environment – Dust (CUACE/Dust forecast system and applied in the operational forecasts of sand and dust storm (SDS in spring 2006. The system is based on a three dimensional variational method (3D-Var and uses extensively the measurements of surface visibility (phenomena and dust loading retrieval from the Chinese geostationary satellite FY-2C. By a number of case studies, the DAS was found to provide corrections to both under- and over-estimates of SDS, presenting a major improvement to the forecasting capability of CUACE/Dust in the short-term variability in the spatial distribution and intensity of dust concentrations in both source regions and downwind areas. The seasonal mean Threat Score (TS over the East Asia in spring 2006 increased from 0.22 to 0.31 by using the data assimilation system, a 41% enhancement. The forecast results with DAS usually agree with the dust loading retrieved from FY-2C and visibility distribution from surface meteorological stations, which indicates that the 3D-Var method is very powerful by the unification of observation and numerical model to improve the performance of forecast model.

  2. 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

    2014-01-01

    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 green-up date and dust 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.

  3. 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.

  4. Review of techniques for magnetic storm forecasting

    Science.gov (United States)

    Detman, Thomas R.; Vassiliadis, Dimitris

    Today a wide variety of techniques are available for nowcasting and forecasting magnetic storm activity. A brief review of linear time series prediction techniques, with examples, is used to lay a foundation for the description of newer non-linear techniques based on state-space reconstruction. We illustrate the state-space prediction technique in application to predict Dst from ISEE-3 solar wind data. Upstream solar wind data, such as from ISEE-3 or WTND close to the L1 libration point, provide a prediction lead time of 0.5-1.5 hours. To go beyond the L1 prediction lead time some information about the solar wind between the Li point and the Sun is required. Remote sensing is the measurement of something from a distance, like solar magnetograms or X-ray images. Both empirical and physically based models, driven by remote sensing data, promise a way to make forecasts a few days into the future. A combination of the statistical time series prediction techniques operating on the output of physically based models, driven by remote sensing data, may offer the first capability of predicting magnetic storms a few days in advance. We illustrate this combination of techniques using the output of a potential field model [Wang and Sheeley, 1988] as input to a linear prediction filter to forecast the planetary geomagnetic index. Finally, practical forecasting requires verification. We describe some of the standard measures of forecast performance: skill score, prediction efficiency, and correlation coefficient. The value of cross validation testing is emphasized.

  5. Dust Storm Feature Identification and Tracking from 4D Simulation Data

    Science.gov (United States)

    Yu, M.; Yang, C. P.

    2016-12-01

    Dust storms cause significant damage to health, property and the environment worldwide every year. To help mitigate the damage, dust forecasting models simulate and predict upcoming dust events, providing valuable information to scientists, decision makers, and the public. Normally, the model simulations are conducted in four-dimensions (i.e., latitude, longitude, elevation and time) and represent three-dimensional (3D), spatial heterogeneous features of the storm and its evolution over space and time. This research investigates and proposes an automatic multi-threshold, region-growing based identification algorithm to identify critical dust storm features, and track the evolution process of dust storm events through space and time. In addition, a spatiotemporal data model is proposed, which can support the characterization and representation of dust storm events and their dynamic patterns. Quantitative and qualitative evaluations for the algorithm are conducted to test the sensitivity, and capability of identify and track dust storm events. This study has the potential to assist a better early warning system for decision-makers and the public, thus making hazard mitigation plans more effective.

  6. CUACE/Dust ─ an integrated system of observation and modeling systems for operational dust forecasting in Asia

    Directory of Open Access Journals (Sweden)

    X. Y. Zhang

    2008-05-01

    Full Text Available An integrated sand and dust storm (SDS forecasting system – CUACE/Dust (Chinese Unified Atmospheric Chemistry Environment for Dust has been developed, which consists of a comprehensive dust aerosol module with emission, dry/wet depositions and other atmospheric dynamic processes, and a data assimilation system (DAS using observational data from the CMA (China Meteorological Administration ground dust monitoring network and retrieved dust information from a Chinese geostationary satellite – FY-2C. This is the first time that a combination of surface network observations and satellite retrievals of the dust aerosol has been successfully used in the real time operational forecasts in East Asia through a DAS. During its application for the operational SDS forecasts in East Asia for spring 2006, this system captured the major 31 SDS episodes observed by both surface and satellite observations. Analysis shows that the seasonal mean threat score (TS for 0–24 h forecast over the East Asia in spring 2006 increased from 0.22 to 0.31 by using the DAS, a 41% enhancement. The time series of the forecasted dust concentrations for a number of representative stations for the whole spring 2006 were also evaluated against the surface PM10 monitoring data, showing a very good agreement in terms of the SDS timing and magnitudes near source regions where dust aerosols dominate. This is a summary paper for a special issue of ACP featuring the development and results of the forecasting system.

  7. Dust modelling and forecasting in the Barcelona Supercomputing Center: Activities and developments

    Energy Technology Data Exchange (ETDEWEB)

    Perez, C; Baldasano, J M; Jimenez-Guerrero, P; Jorba, O; Haustein, K; Basart, S [Earth Sciences Department. Barcelona Supercomputing Center. Barcelona (Spain); Cuevas, E [Izanaa Atmospheric Research Center. Agencia Estatal de Meteorologia, Tenerife (Spain); Nickovic, S [Atmospheric Research and Environment Branch, World Meteorological Organization, Geneva (Switzerland)], E-mail: carlos.perez@bsc.es

    2009-03-01

    The Barcelona Supercomputing Center (BSC) is the National Supercomputer Facility in Spain, hosting MareNostrum, one of the most powerful Supercomputers in Europe. The Earth Sciences Department of BSC operates daily regional dust and air quality forecasts and conducts intensive modelling research for short-term operational prediction. This contribution summarizes the latest developments and current activities in the field of sand and dust storm modelling and forecasting.

  8. Rocket dust storms and detached layers in the Martian atmosphere

    CERN Document Server

    Spiga, Aymeric; Madeleine, Jean-Baptiste; Määttänen, Anni; Forget, François

    2012-01-01

    Airborne dust is the main climatic agent in the Martian environment. Local dust storms play a key role in the dust cycle; yet their life cycle is poorly known. Here we use mesoscale modeling with radiatively-active transported dust to predict the evolution of a local dust storm monitored by OMEGA on board Mars Express. We show that the evolution of this dust storm is governed by deep convective motions. The supply of convective energy is provided by the absorption of incoming sunlight by dust particles, in lieu of latent heating in moist convection on Earth. We propose to use the terminology "rocket dust storm", or conio-cumulonimbus, to describe those storms in which rapid and efficient vertical transport takes place, injecting dust particles at high altitudes in the Martian troposphere (30 to 50 km). Combined to horizontal transport by large-scale winds, rocket dust storms form detached layers of dust reminiscent of those observed with instruments on board Mars Global Surveyor and Mars Reconnaissance Orbite...

  9. Global sand and dust storms in 2008: Observation and HYSPLIT model verification

    Science.gov (United States)

    Wang, Yaqiang; Stein, Ariel F.; Draxler, Roland R.; de la Rosa, Jesús D.; Zhang, Xiaoye

    2011-11-01

    The HYSPLIT model has been applied to simulate the global dust distribution for 2008 using two different dust emission schemes. The first one assumes that emissions could occur from any land-use grid cell defined in the model as desert. The second emission approach uses an empirically derived algorithm based on satellite observations. To investigate the dust storm features and verify the model performance, a global dataset of Integrated Surface Hourly (ISH) observations has been analyzed to map the spatial distribution and seasonal variation of sand and dust storms. Furthermore, the PM 10 concentration data at four stations in Northern China and two stations in Southern Spain, and the AOD data from a station located at the center of the Sahara Desert have been compared with the model results. The spatial distribution of observed dust storm frequency from ISH shows the known high frequency areas located in North Africa, the Middle East, Mongolia and Northwestern China. Some sand and dust storms have also been observed in Australia, Mexico, Argentina, and other sites in South America. Most of the dust events in East Asia occur in the spring, however this seasonal feature is not so evident in other dust source regions. In general, the model reproduces the dust storm frequency for most of the regions for the two emission approaches. Also, a good quantitative performance is achieved at the ground stations in Southern Spain and Western China when using the desert land-use based emissions, although HYSPLIT overestimates the dust concentration at downwind areas of East Asia and underestimates the column in the center of the Saharan Desert. On the other hand, the satellite based emission approach improves the dust forecast performance in the Sahara, but underestimates the dust concentrations in East Asia.

  10. Characteristics and sources of 2002 super dust storm in Beijing

    Institute of Scientific and Technical Information of China (English)

    SUN Yele; ZHUANG Guoshun; YUAN Hui; ZHANG Xingying; GUO Jinghua

    2004-01-01

    On 20 March, 2002, a super dust storm attacked Beijing, which was stronger than any dust storm ever recorded. The concentration of total suspended particulates air quality standard. The concentrations of major crustal elements, such as Ca, Al, Fe, Na, Mg and Ti, were 30-58times higher than those in non-dust storm days. The concentrations of pollution elements, such as Zn, Cu, Pb, As, Cd and S, were also about several or even nearly ten times higher than those in normal days. The enrichment factors of Pb, As, Cd and S in PM2.5 were as high as 12.7, 29.6, 43.5,28.4, indicating that these pollutants came from the mixing of mineral aerosol with pollution aerosol emitted by pollution sources on the way of dust storm's long-range transport. The overlap of invaded air mass from dust with pollution air mass from Beijing local area was another reason for the enhancement of pollutants. During dust storm, fine particles (PM2.5) accounted for 30% of TSP and pollutants in PM2.5accounted for even as high as 45%-69% of TSP. The increase of pollutants after dust storm proved further that mineral aerosol, especially the fine particles from dust storm favored the transformation and accumulation of pollutants.It must be noted that Fe (Ⅱ) was detected again in this dust storm, which provided new evidence for the mechanism of coupling and feedback between iron and sulfur in the atmosphere and the ocean. The increase of both pollutants and nutrient, Fe(Ⅱ), during dust storm illuminated that dust storm is an important factor affecting the global environment change.

  11. Saline dust storms and their ecological impacts in arid regions

    Institute of Scientific and Technical Information of China (English)

    Jilili; Abuduwaili

    2010-01-01

    In many arid and semiarid regions,saline playas represent a significant source of unconsoli-dated sediments available for aeolian transport,and severe saline dust storms occur frequently due to human disturbance.In this study,saline dust storms are reviewed systematically from the aspects of con-cept,general characteristics,conditions of occurrence,distribution and ecological impact.Our researches showed that saline dust storms are a kind of chemical dust storm originating in dry lake beds in arid and semiarid regions;large areas of unconsolidated saline playa sediments and frequent strong winds are the basic factors to saline dust storm occurrence;there are differentiation characteristics in deposition flux and chemical composition with wind-blown distance during saline dust storm diffusion;and saline dust storm diffusion to some extent increases glacier melt and results in soil salinization in arid regions.An under-standing of saline dust storms is important to guide disaster prevention and ecological rehabilitation.

  12. The impact of dust storms on the Arabian Peninsula and the Red Sea

    Directory of Open Access Journals (Sweden)

    P. Jish Prakash

    2014-07-01

    Full Text Available 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 on 18–20 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, North-Eastern Africa, Afghanistan and Pakistan. It was caused by a southward propagating cold front and 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, 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. The total amount of dust generated by the storm reached 93.76 Mt. About 80% of this amount deposited within the calculation domain. The Arabian Sea and Persian Gulf received 5.3 Mt, and the Red Sea 1.2 Mt. Dust particles bring nutrients to marine ecosystems, which is especially important for the oligothrophic 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 roughly estimate the annual dust deposition to the Red Sea to be 6 Mt.

  13. Maps of the MY 25 Planet-encircling Dust Storm

    Science.gov (United States)

    Noble, J.; Cantor, B. A.; Wilson, R. J.; Haberle, R. M.; Bridger, A. F. C.; Barnes, J.; Hollingsworth, J. L.; Kahre, M. A.

    2015-12-01

    We have created 42 daily maps of the MY 25 planet-encircling dust storm (Ls=165-188) in order to better delimit the areal extent of storms observed by the Mars Orbiter Camera (MOC). These maps allow us to better compare storm evolution with eddies observed in Fast Fourier Synoptic Mapping (FFSM) of Thermal Emission Spectrometer (TES) temperatures. FFSM analysis of TES 3.7 hPa thermal data shows the presence of eastward traveling waves from 40 - 60° S with a period of about three sols. These maps use a new dust characterization scheme that categorizes dust storms and dust entrained in gravity waves by degree of (visual) structure. Preliminary analysis of these data indicate concurrent eastward migration of both storms and eddies. We hypothesize that these waves are transient baroclinic eddies that contributed to the initiation of precursor storms near Hellas.

  14. Atmospheric Bioaerosols Transported Via Dust Storms in Western United States

    Science.gov (United States)

    Mccubbin, I. B.; Hallar, A. G.; Painter, T. H.; Wiedinmyer, C.; Chirokova, G.

    2011-12-01

    Measurements are presented showing the presence of biological material within frequent dust storms in the Western United States. Previous work has indicated that biological particles were enhancing the impact of dust storms on the formation of clouds. This paper presents multiple case studies, between April and May 2010, showing the presence of and quantifying the amount of biological material via an Ultraviolet Aerodynamic Particle Sizer during dust events. All dust storms originated in the Four Corners region in the Western U.S. and were measured at Storm Peak Laboratory, a high elevation facility in northwestern Colorado. From an Aerodynamic Particle Sizer, the mean dust particle size during these events was approximately 23 1μm, with number concentrations between 6 cm-3 and 12 cm-3. Approximately 0.2% of these dust particles had fluorescence signatures, indicating the presence of biological material.

  15. Interannual variability of planet-encircling dust storms on Mars

    Science.gov (United States)

    Zurek, Richard W.; Martin, Leonard J.

    1993-01-01

    A recent review of earth-based telescopic observations of Mars together with Viking orbiter and lander data are employed to estimate the frequency of occurrence of planet-encircling dust storms over the past century and to test whether the period spanned by the Mariner 9 and Viking missions to Mars is representative of the decades prior to 1950. Both spacecraft and earth-based observations suggest that planet-encircling dust storms on Mars occur during a 'dust storm season' in southern spring and summer. Viking data show that planet-encircling dust storms could have occurred in the past on Mars without being detected from earth during years in which Mars was far from earth during the dust storm season. Planet-encircling storms were absent during the dust storm seasons monitored during several favorable oppositions prior to 1956 and after 1986. The change of a planet-encircling dust storm occurring in any arbitrary Mars year is estimated to be approximately one in three, if this occurrence is random from year to year and yet restricted seasonally to southern spring and summer.

  16. Development and Evaluation of Storm Surge Ensemble Forecasting for the Philippines Using JMA Storm Surge Model

    Science.gov (United States)

    Lapidez, J. P. B.; Tablazon, J. P.; Lagmay, A. M. F. A.; Suarez, J. K. B.; Santiago, J. T.

    2014-12-01

    The Philippines is one of the countries most vulnerable to storm surge. It is located in the North-western Pacific basin which is the most active basin in the planet. An average of 20 tropical cyclones enters the Philippine area of responsibility (PAR) every year. The archipelagic nature of the country with regions having gently sloping coasts and shallow bays also contribute to the formation of extreme surges. Last November 2013, storm surge brought by super typhoon Haiyan severely damaged several coastal regions in the Visayan Islands. Haiyan left more than 6 300 casualties and damages amounting to more than $ 2 billion. Extreme storm surge events such as this highlight the need to establish a storm surge early warning system for the country. This study explores the development and evaluation of storm surge ensemble forecasting for the Philippines using the Japan Meteorological Agency (JMA) storm surge model. 36-hour, 24-hour, and 12-hour tropical cyclone forecasts are used to generate an ensemble storm surge forecast to give the most probable storm surge height at a specific point brought by an incoming tropical cyclone. The result of the storm surge forecast is compared to tide gauge record to evaluate the accuracy. The total time of computation and dissemination of forecast result is also examined to assess the feasibility of using the JMA storm surge model for operational purposes.

  17. WMO Sand and Dust Storm Warning Advisory and Assessment System (SDS-WAS): Research Implementation Status

    Science.gov (United States)

    Nickovic, Slobodan; Barrie, Leonard

    2010-05-01

    Strong winds cause lifting of large amounts of sand and dust from bare, dry soils into the atmosphere. For countries in and downwind of arid regions, airborne sand and dust presents serious risks to the environment, property and human health. Impacts on health include respiratory and cardio-vascular problems, eye infections and in some regions, diseases such as meningitis and valley fever. Dust can efficiently carry irritating spores, bacteria, viruses and persistent organic pollutants. It can also efficiently transport nutrients to parts of the world oceans and affect marine biomass production. Other impacts include negative effects on the ground transport, aviation, agriculture and visibility. The Inter-governmental Panel on Climate Change (IPCC) recognizes dust as a major component of the atmospheric aerosol that is an essential climate variable. Dust aerosol has important effects on weather through feedback on atmospheric dynamics, clouds and precipitation formation. Approximately 15 centres around the world provide sand and dust research operational forecasts. Many are operated by national meteorological services of the World Meteorological Organization (WMO). Sand and dust storm models can substantially reduce risk by providing dust concentration predictions for several days in advance. Numerical weather prediction systems that drive these models use complex parameterizations and assimilation of satellite, and surface-based observations to predict winds, clouds, precipitation and dust mobilization, transport, and removal from the atmosphere. Sand and dust forecast products contribute to the mitigation and reduction of risk through research based advances in understanding and forecasting products. Observations of sand and dust are made by many agencies and some of them are being coordinated globally through the WMO Global Atmosphere Watch (GAW) programme. In 2006, WMO and partners initiated the implementation of the Sand and Dust Storm Warning Advisory and

  18. Using forecast information for storm ride-through control

    DEFF Research Database (Denmark)

    Barahona Garzón, Braulio; Trombe, Pierre-Julien; Vincent, Claire Louise;

    2013-01-01

    Using probabilistic forecast information in control algorithms can improve the performance of wind farms during periods of extreme winds. This work presents a wind farm supervisor control concept that uses probabilistic forecast information to ride-through a storm with softer ramps of power. Wind...

  19. Analysis of synoptic situation for dust storms in Iraq

    Energy Technology Data Exchange (ETDEWEB)

    Al-Jumaily, Kais J.; Ibrahim, Morwa K. [Department of Atmospheric Sciences, College of Science, Al-Mustansiriyah University, Baghdad (Iraq)

    2013-07-01

    Dust storms are considered major natural disasters that cause many damages to society and environment in Iraq and surrounded deserted regions. The aim of this research is to analyze and study the synoptic patterns leading to the formation of dust storms in Iraq. Analysis are based on satellite images, aerosols index and synoptic weather maps. Two severe dust storms occurred over Iraq on February 22, 2010, and on December 10, 2011 were analyzed. The results showed that dust storms form when a low-pressure system forms over Iran causing Shamal winds blow; they carry cool air from that region towards warmer regions like eastern Syria and Iraq. In some cases, this low-pressure system is followed by a high-pressure system brining more cold air to the region and pushing dust toward south. Dust storms are initiated from source regions near Iraq-Syria borders by the existence of negative vertical velocity, which causes dust particles to be lifted upwards, and the strong westerly wind drives dust to travel eastward.

  20. Dust Storm Impacts on Human Mars Mission Equipment and Operations

    Science.gov (United States)

    Rucker, M. A.

    2017-06-01

    NASA has accumulated a wealth of experience between the Apollo program and robotic Mars rover programs, but key differences between those missions and a human Mars mission that will require unique approaches to mitigate potential dust storm concerns.

  1. Effect of dust storms on FSO communications links

    KAUST Repository

    Esmail, Maged Abdullah

    2017-05-18

    In literature, there is a lake of information about free space optic (FSO) systems\\' performance in arid and semi-arid areas that are prone to frequent dust storms. Therefore, in this paper, we investigate the performance of FSO links under dust storm conditions. We aim to determine the limits and capabilities of such systems in this harsh environment. To achieve this goal, we use some performance metrics including signal-to-noise (SNR) ratio, bit error rate (BER), and channel capacity. The results show that dust is a rough impairment that causes link drop under low visibility range. Moreover, we found that the system performance can be improved by using short segments or multi-hop system. Furthermore, the results show negligible improvement in system performance under dense dust. The comparison of fog and dust impairments show that dust introduces much higher attenuation than fog. Therefore, dust can be considered as the ultimate impairment for FSO links.

  2. Where Do the Sand-Dust Storms Come From?: Conversations with Specialists from the Exploring Sand-Dust Storms Scientific Expedition Team

    Science.gov (United States)

    Shixin, Liu

    2004-01-01

    This article relates the different views from specialists of the scientific expedition team for the exploration of the origin of sand-dust storms. They observed and examined on-site the ecological environment of places of origin for sand-dust storms, and tried to find out causes of sand-dust storm and what harm it can cause in the hope of…

  3. The Association between Dust Storms and Daily Non ...

    Science.gov (United States)

    Background:The impact of dust storms on human health has been studied in the context of Asian,Saharan, Arabian, and Australian storms,but there has been no recent population-level epidemiological research on the dust storms in North America . The relevance of dust storms to public health is likely to increase as extreme weather events are predicted to become more frequent with anticipated changes in climate through the 21st century.Objectives: We examined the association between dust storms and county-level non-accidental mortality in the United States from 1993 through 2005.Methods:Dust storm incidence data, including date and approximate location. are taken from the U.S. National Weather Service storm database. County-level mortality data for the years 1993-2005 were acquired from the National Center for Health Statistics. Distributed lag conditionallogistic regression models under a time-stratified case-crossover design were used to study the relationship between dust storms and daily mortality counts over the whole United States and in Arizona and California specifically. End points included total non-accidental mortality and three mortality subgroups (cardiovascular, respiratory, and other non-acc idental).Results: We estimated that for the United States as a whole, total non-accidental mortality increased by 7.4% (95% Cl: 1.6, 13.5; p = 0.011) and 6.7% (95% Cl: 1.1,12.6; p = 0.018) at 2- and 3-day lags, respectively, and by an average of 2.7% (95% Cl: 0.4,

  4. Storm surges in the Western Black Sea. Operational forecasting

    Directory of Open Access Journals (Sweden)

    G. MUNGOV

    2012-12-01

    Full Text Available The frequency of the storm surges in the Black Sea is lower than that in other regions of the World Ocean but they cause significant damages as the magnitude of the sea level set-up is up to 7-8 times greater than that of other sea level variations. New methods and systems for storm surge forecasting and studying their statistical characteristics are absolutely necessary for the purposes of the coastal zone management. The operational forecasting storm surge model of Meteo-France was adopted for the Black Sea in accordance with the bilateral agreement between Meteo-France and NINMH. The model was verified using tide-gauge observations for the strongest storms observed along the Bulgarian coast over the last 10 years.

  5. Seasonal Verification of Dust Forecast over the Indian Region

    Science.gov (United States)

    Fatima, Hashmi; George, John P.; Rajagopal, E. N.; Basu, Swati

    2017-07-01

    The medium-range forecast of the dust aerosols over Indian region produced by the NCMRWF numerical weather prediction model with mineral dust scheme from May 2013 to May 2014 is examined in this study. Coarse mode aerosol observations are only used for comparison with dust forecast with the assumption that coarse mode aerosol over Indian region largely represents dust aerosol, especially over the areas of high dust load. Accuracy and trends of the day-to-day dust forecast are studied at three AERONET locations in Indo-Gangetic Plains (IGP) using surface and MODIS satellite retrievals of coarse mode aerosol optical depth for entire one year (May 2013-May 2014). Seasonal mean geographical distribution of the medium-range forecast of dust by the model over Indian region is validated with different satellite retrievals for all four seasons. Availability of suitable observations is one of the limiting factors and big challenges for the validation of the dust forecast. The main focus of this study is to assess dust forecast by the model over Indian region for all seasons, to know the biases and errors of the model forecast for its optimal use. The study finds that model dust forecast is comparable to AERONET observations over three locations for all seasons except monsoon season.

  6. Regional dust storm modeling for health services: The case of valley fever

    Science.gov (United States)

    Sprigg, William A.; Nickovic, Slobodan; Galgiani, John N.; Pejanovic, Goran; Petkovic, Slavko; Vujadinovic, Mirjam; Vukovic, Ana; Dacic, Milan; DiBiase, Scott; Prasad, Anup; El-Askary, Hesham

    2014-09-01

    On 5 July 2011, a massive dust storm struck Phoenix, Arizona (USA), raising concerns for increased cases of valley fever (coccidioidomycosis, or, cocci). A quasi-operational experimental airborne dust forecast system predicted the event and provides model output for continuing analysis in collaboration with public health and air quality communities. An objective of this collaboration was to see if a signal in cases of valley fever in the region could be detected and traced to the storm - an American haboob. To better understand the atmospheric life cycle of cocci spores, the DREAM dust model (also herein, NMME-DREAM) was modified to simulate spore emission, transport and deposition. Inexact knowledge of where cocci-causing fungus grows, the low resolution of cocci surveillance and an overall active period for significant dust events complicate analysis of the effect of the 5 July 2011 storm. In the larger context of monthly to annual disease surveillance, valley fever statistics, when compared against PM10 observation networks and modeled airborne dust concentrations, may reveal a likely cause and effect. Details provided by models and satellites fill time and space voids in conventional approaches to air quality and disease surveillance, leading to land-atmosphere modeling and remote sensing that clearly mark a path to advance valley fever epidemiology, surveillance and risk avoidance.

  7. Performance Comparison of the European Storm Surge Models and Chaotic Model in Forecasting Extreme Storm Surges

    Science.gov (United States)

    Siek, M. B.; Solomatine, D. P.

    2009-04-01

    Storm surge modeling has rapidly developed considerably over the past 30 years. A number of significant advances on operational storm surge models have been implemented and tested, consisting of: refining computational grids, calibrating the model, using a better numerical scheme (i.e. more realistic model physics for air-sea interaction), implementing data assimilation and ensemble model forecasts. This paper addresses the performance comparison between the existing European storm surge models and the recently developed methods of nonlinear dynamics and chaos theory in forecasting storm surge dynamics. The chaotic model is built using adaptive local models based on the dynamical neighbours in the reconstructed phase space of observed time series data. The comparison focused on the model accuracy in forecasting a recently extreme storm surge in the North Sea on November 9th, 2007 that hit the coastlines of several European countries. The combination of a high tide, north-westerly winds exceeding 50 mph and low pressure produced an exceptional storm tide. The tidal level was exceeded 3 meters above normal sea levels. Flood warnings were issued for the east coast of Britain and the entire Dutch coast. The Maeslant barrier's two arc-shaped steel doors in the Europe's biggest port of Rotterdam was closed for the first time since its construction in 1997 due to this storm surge. In comparison to the chaotic model performance, the forecast data from several European physically-based storm surge models were provided from: BSH Germany, DMI Denmark, DNMI Norway, KNMI Netherlands and MUMM Belgium. The performance comparison was made over testing datasets for two periods/conditions: non-stormy period (1-Sep-2007 till 14-Oct-2007) and stormy period (15-Oct-2007 till 20-Nov-2007). A scalar chaotic model with optimized parameters was developed by utilizing an hourly training dataset of observations (11-Sep-2005 till 31-Aug-2007). The comparison results indicated the chaotic

  8. 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.

  9. Characterisation of atmospheric deposited particles during a dust storm in urban areas of Eastern Australia.

    Science.gov (United States)

    Gunawardena, Janaka; Ziyath, Abdul M; Bostrom, Thor E; Bekessy, Lambert K; Ayoko, Godwin A; Egodawatta, Prasanna; Goonetilleke, Ashantha

    2013-09-01

    The characteristics of dust particles deposited during the 2009 dust storm in the Gold Coast and Brisbane regions of Australia are discussed in this paper. The study outcomes provide important knowledge in relation to the potential impacts of dust storm related pollution on ecosystem health in the context that the frequency of dust storms is predicted to increase due to anthropogenic desert surface modifications and climate change impacts. The investigated dust storm contributed a large fraction of fine particles to the environment with an increased amount of total suspended solids, compared to dry deposition under ambient conditions. Although the dust storm passed over forested areas, the organic carbon content in the dust was relatively low. The primary metals present in the dust storm deposition were aluminium, iron and manganese, which are common soil minerals in Australia. The dust storm deposition did not contain significant loads of nickel, cadmium, copper and lead, which are commonly present in the urban environment. Furthermore, the comparison between the ambient and dust storm chromium and zinc loads suggested that these metals were contributed to the dust storm by local anthropogenic sources. The potential ecosystem health impacts of the 2009 dust storm include, increased fine solids deposition on ground surfaces resulting in an enhanced capacity to adsorb toxic pollutants as well as increased aluminium, iron and manganese loads. In contrast, the ecosystem health impacts related to organic carbon and other metals from dust storm atmospheric deposition are not considered to be significant.

  10. Development of high-resolution dynamic dust source function - A case study with a strong dust storm in a regional model

    Science.gov (United States)

    Kim, Dongchul; Chin, Mian; Kemp, Eric M.; Tao, Zhining; Peters-Lidard, Christa D.; Ginoux, Paul

    2017-06-01

    A high-resolution dynamic dust source has been developed in the NASA Unified-Weather Research and Forecasting (NU-WRF) model to improve the existing coarse static dust source. In the new dust source map, topographic depression is in 1-km resolution and surface bareness is derived using the Normalized Difference Vegetation Index (NDVI) data from Moderate Resolution Imaging Spectroradiometer (MODIS). The new dust source better resolves the complex topographic distribution over the Western United States where its magnitude is higher than the existing, coarser resolution static source. A case study is conducted with an extreme dust storm that occurred in Phoenix, Arizona in 02-03 UTC July 6, 2011. The NU-WRF model with the new high-resolution dynamic dust source is able to successfully capture the dust storm, which was not achieved with the old source identification. However the case study also reveals several challenges in reproducing the time evolution of the short-lived, extreme dust storm events.

  11. A High Resolution Forecast Model of Storm Surge Inundation

    Institute of Scientific and Technical Information of China (English)

    LIU Juan; JIANG Wensheng; SUN Wenxin; WANG Yongzhi

    2005-01-01

    In order to forecast storm surge inundation, a two-dimensional model is established. In the model, an alternating computation sequence method is used to solve the governing equations, and the dry and wet method is introduced to treat the moving boundary. This model is easy to use. It has a friendly input interface and Arcview GIS is used as the output interface. The model is applied to the Shantou area to simulate the storm surge elevations and inundations caused by Typhoons 6903 ane 0104 using the same relevant parameters. The calculated results agree well with the observations.

  12. Surface Properties Associated With Dust Storm Plume's Point-Source Locations In The Border Region Of The US And Mexico

    Science.gov (United States)

    Bleiweiss, M. P.; DuBois, D. W.; Flores, M. I.

    2013-12-01

    Dust storms in the border region of the Southwest US and Northern Mexico are a serious problem for air quality (PM10 exceedances), health (Valley Fever is pandemic in the region) and transportation (road closures and deadly traffic accidents). In order to better understand the phenomena, we are attempting to identify critical characteristics of dust storm sources so that, possibly, one can perform more accurate predictions of events and, thus, mitigate some of the deleterious effects. Besides the emission mechanisms for dust storm production that are tied to atmospheric dynamics, one must know those locations whose source characteristics can be tied to dust production and, therefore, identify locations where a dust storm is eminent under favorable atmospheric dynamics. During the past 13 years, we have observed, on satellite imagery, more than 500 dust events in the region and are in the process of identifying the source regions for the dust plumes that make up an event. Where satellite imagery exists with high spatial resolution (less than or equal to 250m), dust 'plumes' appear to be made up of individual and merged plumes that are emitted from a 'point source' (smaller than the resolution of the imagery). In particular, we have observed events from the ASTER sensor whose spatial resolution is 15m as well as Landsat whose spatial resolution is 30m. Tying these source locations to surface properties such as NDVI, albedo, and soil properties (percent sand, silt, clay, and gravel; soil moisture; etc.) will identify regions with enhanced capability to produce a dust storm. This, along with atmospheric dynamics, will allow the forecast of dust events. The analysis of 10 events from the period 2004-2013, for which we have identified 1124 individual plumes, will be presented.

  13. Desertification and Dust Storms in China: Impacts, Root Causes and Mitigation Strategies

    Institute of Scientific and Technical Information of China (English)

    LU Qi; WANG Sen; SQUIRES Victor; YANG Youlin

    2006-01-01

    Desertification and dust storms and their impact on the Chinese economy and the environment were examined. A context was established using the best information available on the trends of desertification and dust storms in China. Building on the context, the second section the root causes of desertification and dust storms were examined. Several myths were sought to be identified about some core issues surrounding desertification and dust storms. China's National Action Plan to combat desertification was reviewed and the effectiveness of existing strategies and programs for mitigating the adverse effects of desertification and dust storms were discussed. The future research needed was pointed out.

  14. A multi-scale hybrid neural network retrieval model for dust storm detection, a study in Asia

    Science.gov (United States)

    Wong, Man Sing; Xiao, Fei; Nichol, Janet; Fung, Jimmy; Kim, Jhoon; Campbell, James; Chan, P. W.

    2015-05-01

    Dust storms are known to have adverse effects on human health and significant impact on weather, air quality, hydrological cycle, and ecosystem. Atmospheric dust loading is also one of the large uncertainties in global climate modeling, due to its significant impact on the radiation budget and atmospheric stability. Observations of dust storms in humid tropical south China (e.g. Hong Kong), are challenging due to high industrial pollution from the nearby Pearl River Delta region. This study develops a method for dust storm detection by combining ground station observations (PM10 concentration, AERONET data), geostationary satellite images (MTSAT), and numerical weather and climatic forecasting products (WRF/Chem). The method is based on a hybrid neural network (NN) retrieval model for two scales: (i) a NN model for near real-time detection of dust storms at broader regional scale; (ii) a NN model for detailed dust storm mapping for Hong Kong and Taiwan. A feed-forward multilayer perceptron (MLP) NN, trained using back propagation (BP) algorithm, was developed and validated by the k-fold cross validation approach. The accuracy of the near real-time detection MLP-BP network is 96.6%, and the accuracies for the detailed MLP-BP neural network for Hong Kong and Taiwan is 74.8%. This newly automated multi-scale hybrid method can be used to give advance near real-time mapping of dust storms for environmental authorities and the public. It is also beneficial for identifying spatial locations of adverse air quality conditions, and estimates of low visibility associated with dust events for port and airport authorities.

  15. A numerical storm surge forecast model with Kalman filter

    Institute of Scientific and Technical Information of China (English)

    Yu Fujiang; Zhang Zhanhai; Lin Yihua

    2001-01-01

    Kalman filter data assimilation technique is incorporated into a standard two-dimensional linear storm surge model. Imperfect model equation and imperfect meteorological forcimg are accounted for by adding noise terms to the momentum equations. The deterministic model output is corrected by using the available tidal gauge station data. The stationary Kalman filter algorithm for the model domain is calculated by an iterative procedure using specified information on the inaccuracies in the momentum equations and specified error information for the observations. An application to a real storm surge that occurred in the summer of 1956 in the East China Sea is performed by means of this data assimilation technique. The result shows that Kalman filter is useful for storm surge forecast and hindcast.

  16. An Investigation of Dust Storms Observed with the Mars Color Imager

    Science.gov (United States)

    Guzewich, Scott D.; Toigo, Anthony D.; Wang, Huiqun

    2017-01-01

    Daily global imaging by the Mars Color Imager (MARCI) continues the record of the Mars Orbiter Camera (MOC) and has allowed creation of a long-duration record of Martian dust storms. We observe dust storms over the first two Mars years of the MARCI record, including tracking individual storms over multiple sols, as well as tracking the growth and recession of the seasonal polar caps. Using the combined 6 Mars year record of textured dust storms (storms with visible textures on the observed dust cloud tops), we study the relationship between textured dust storm activity and meteorology (as simulated by the MarsWRF general circulation model) and surface properties. We find that textured dust storms preferentially occur in places and seasons with above average surface wind stress. Textured dust storm occurrence also has a modest linear anti-correlation with surface albedo (0.43) and topography (0.40). Lastly, we perform an empirical orthogonal function (EOF) analysis on the distribution of occurrence of textured dust storms and find that over 50 of the variance in textured dust storm activity can be explained by two EOF modes. We associate the first EOF mode with cap-edge storms just before Ls = 180deg and the second EOF mode with flushing dust storms that occur from Ls = 180-210deg and again near Ls = 320deg.

  17. An investigation of dust storms observed with the Mars Color Imager

    Science.gov (United States)

    Guzewich, Scott D.; Toigo, Anthony D.; Wang, Huiqun

    2017-06-01

    Daily global imaging by the Mars Color Imager (MARCI) continues the record of the Mars Orbiter Camera (MOC) and has allowed creation of a long-duration record of Martian dust storms. We observe dust storms over the first two Mars years of the MARCI record, including tracking individual storms over multiple sols, as well as tracking the growth and recession of the seasonal polar caps. Using the combined 6 Mars year record of textured dust storms (storms with visible textures on the observed dust cloud tops), we study the relationship between textured dust storm activity and meteorology (as simulated by the MarsWRF general circulation model) and surface properties. We find that textured dust storms preferentially occur in places and seasons with above average surface wind stress. Textured dust storm occurrence also has a modest linear anti-correlation with surface albedo (-0.43) and topography (-0.40). Lastly, we perform an empirical orthogonal function (EOF) analysis on the distribution of occurrence of textured dust storms and find that over 50% of the variance in textured dust storm activity can be explained by two EOF modes. We associate the first EOF mode with cap-edge storms just before Ls = 180° and the second EOF mode with flushing dust storms that occur from Ls = 180-210° and again near Ls = 320°.

  18. Development of a Forecasting and Data Assimilation System for Asian Dust in the Japan Meteorological Agency (JMA)

    Science.gov (United States)

    Yumimoto, K.; Tanaka, T. Y.; Ogi, A.; Sekiyama, T. T.; Maki, T.; Murakami, H.; Kikuchi, M.; Nagao, T. M.

    2015-12-01

    Mineral dust, a major aerosol during springtime in East Asia, impacts various aspects including social activity, human health, climate and the ocean ecosystem. To mitigate the damage of severe dust storms, it is crucial to develop a forecasting and early warning system for Asian dust. Since 2007, the World Meteorological Organization (WMO) has taken the lead with 40 international partners to develop a Sand and Dust Storm Warning Advisory and Assessment System (SDS-WAS). The Japan Meteorological Agency (JMA) launched a numerical forecasting system for Asian dust in 2004, and completed a major renovation of the system in November 2014. In the renovation, we replaced a general circulation model (the JMA98 GCM) and dust emission scheme (based on wind velocity at 10 m) with new ones (the GSMUV GCM and a friction velocity based emission scheme). A 5-year validation exhibits that the renovation achieves better forecasting score (especially in short range forecast). Our group has resolution improvement (up to ~40 km) and implementation of data assimilation with satellite observations in the upcoming updates. A feasibility study on involving observations from Himawari-8 (JMA's new geostationary meteorological satellite) into the system is also conducted for better forecasting skill and toward robust early warning.

  19. Climate controls on dust storm occurrence in Maowusu Desert, Inner Mongolia, North China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Dust storms occurring in arid and semi-arid regions play a main role in the evolution of landscapes. Climate is generally regarded to be important factors influencing the occurrence of dust storm, however, the way of climate controlling dust storms had been poorly understood. In this paper, we present the Ew Index model to describe the relationship between climate variables and dust storm frequency using the available meteorological data from three meteorological stations in Maowusu Desert. This index model explains 96.8%, 69.8% and 65.3% of the variance of dust storm frequency in three regions from the north to the south,respectively and this difference is probably caused by the difference of the human disturbance. The Ew Index model is an effective predictor of dust storm frequency and provides us a quite good understanding on the occurrence of dust storms in Maowusu Desert.

  20. PREFACE: WMO/GEO Expert Meeting On An International Sand And Dust Storm Warning System

    Science.gov (United States)

    Pérez, C.; Baldasano, J. M.

    2009-03-01

    developing applications focusing on societal benefit and risk reduction. However, at present there are interdisciplinary research challenges to overwhelm current uncertainties in order to reach full potential. Furthermore, the community of practice for SDS observations, forecasts and analyses is mainly scientifically based and rather disconnected from potential users. This requires the development of interfaces with operational communities at international and national levels, strongly focusing on the needs of people and factors at risk. The WMO has taken the lead with international partners to develop and implement a Sand and Dust Storm Warning Advisory and Assessment System (SDS-WAS). The history of the WMO SDS-WAS development is as follows. On 12-14 September 2004, an International Symposium on Sand and Dust Storms was held in Beijing at the China Meteorological Agency followed by a WMO Experts Workshop on Sand and Dust Storms. The recommendations of that workshop led to a proposal to create a WMO Sand and Dust Storm Project coordinated jointly with the Global Atmosphere Watch (GAW). This was approved by the steering body of the World Weather Research Programme (WWRP) in 2005. Responding to a WMO survey conducted in 2005, more than forty WMO Member countries expressed interest in participating in activities to improve capacities for more reliable sand and dust storm monitoring, forecasting and assessment. On 31 October to 1 November 2006 in Shanghai, the steering committee of the Sand and Dust Storm Project proposed the development and implementation of a Sand and Dust Storm Warning, Advisory and Assessment System (SDS-WAS). The WMO Secretariat in Geneva formed an ad-hoc Internal Group on SDS-WAS consisting of scientific officers representing WMO research, observations, operational prediction, service delivery and applications programmes such as aviation and agriculture. In May 2007, the 14th WMO Congress endorsed the launching of the SDS-WAS. It also welcomed the strong

  1. Paracas dust storms: Sources, trajectories and associated meteorological conditions

    Science.gov (United States)

    Briceño-Zuluaga, F.; Castagna, A.; Rutllant, J. A.; Flores-Aqueveque, V.; Caquineau, S.; Sifeddine, A.; Velazco, F.; Gutierrez, D.; Cardich, J.

    2017-09-01

    Dust storms that develop along the Pisco-Ica desert in Southern Peru, locally known as ;Paracas; winds have ecological, health and economic repercussions. Here we identify dust sources through MODIS (Moderate Resolution Imaging Spectroradiometer) imagery and analyze HYSPLIT (Hybrid Single Particles Lagrangian Integrated Trajectory) model trajectories and dispersion patterns, along with concomitant synoptic-scale meteorological conditions from National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis (NCEP/NCAR). Additionally, surface pressure data from the hourly METeorological Aerodrome Report (METAR) at Arica (18.5°S, 70.3°W) and Pisco (13.7°S, 76.2°W) were used to calculate Alongshore (sea-level) Pressure Gradient (APG) anomalies during Paracas dust storms, their duration and associated wind-speeds and wind directions. This study provides a review on the occurrence and strength of the Paracas dust storms as reported in the Pisco airfield for five-year period and their correspondence with MODIS true-color imagery in terms of dust-emission source areas. Our results show that most of the particle fluxes moving into the Ica-Pisco desert area during Paracas wind events originate over the coastal zone, where strong winds forced by steep APGs develop as the axis of a deep mid-troposphere trough sets in along north-central Chile. Direct relationships between Paracas wind intensity, number of active dust-emission sources and APGs are also documented, although the scarcity of simultaneous METAR/MODIS data for clearly observed MODIS dust plumes prevents any significant statistical inference. Synoptic-scale meteorological composites from NCEP/NCAR reanalysis data show that Paracas wind events (steep APGs) are mostly associated with the strengthening of anticyclonic conditions in northern Chile, that can be attributed to cold air advection associated with the incoming trough. Compared to the MODIS images, HYSPLIT outputs were able

  2. Gobi dust storms and The Great Green Wall

    Science.gov (United States)

    Parungo, Farn; Li, Zhe; Li, Xingsheng; Yang, Dongzeng; Harris, Joyce

    1994-06-01

    Vast belts of forest planted across the northern arid lands of China, called “The Great Green Wall,” are probably one of the most aggressive weather modification programs in the twentieth century. The purpose is to reduce eolian transport of dust from the Gobi Desert. Preliminary data indicate a negative trend in dust-storm frequency and duration since the 1960s. Effects on atmospheric radiation and cloud microphysics appear to be statistically insignificant in the studied period. However, only time can show any long-term impact on our environment.

  3. Update on modifications to WRF-CHEM GOCART for fine-scale dust forecasting at AFWA

    Science.gov (United States)

    Jones, S. L.; Adams-Selin, R.; Hunt, E. D.; Creighton, G. A.; Cetola, J. D.

    2012-12-01

    Dust storms create hazardous health and visibility conditions. Researchers at the Air Force Weather Agency (AFWA) and Atmospheric and Environmental Research (AER) are continuing to develop a suite of mesoscale and convective-scale dust forecasting products using the Weather Research and Forecasting - Chemistry (WRF-CHEM) model coupled with the GOddard Chemistry Aerosol Radiation and Transport (GOCART) dust model. A brief survey of changes made to the GOCART dust emission scheme by AFWA and affiliates is provided. These include changes to the model's saltation algorithm and emitted particle size distribution, as well as modifications to the method for determining soil moisture impact on the dust lofting threshold. A new preferential dust source region, created by the Desert Research Institute, is also evaluated. These variations are verified using subjective satellite dust observations, as well as aerosol optical depth data from Aerosol Robotic NETwork (AERONET) stations and the Multi-angle Imaging SpectroRadiometer (MISR) and Moderate Resolution Imaging Spectroradiometer (MODIS) satellites. Integration of these new variations into an ensemble framework will also be discussed.

  4. Aerosol optical absorption by dust and black carbon in Taklimakan Desert, during no-dust and dust-storm conditions

    Institute of Scientific and Technical Information of China (English)

    Hui Lu; Wenshou Wei; Mingzhe Liu; Weidong Gao; Xi Han

    2012-01-01

    Aerosol absorption coefficient σap involves the additive contribution of both black carbon aerosol (BC) and dust aerosol.The linear statistical regression analysis approach introduced by Fialho et al.(2005) is used to estimate the absorption exponents of BC and dust aerosol absorption coefficients,and further to separate the contributions of these two types of aerosols from the total light absorption coefficient measured in the hinterland of Taklimakan Desert in the spring of 2006.Absorption coefficients are measured by means of a 7-wavelength Aethalometer from 1 March to 31 May and from 1 November to 28 December,2006.The absorption exponent of BC absorption coefficient α is estimated as (-0.95 ±0.002) under background weather (supposing the observed absorption coefficient is due only to BC); the estimated absorption exponent of dust aerosol absorption coefficient β during the 6 dust storm periods (strong dust storm) is (-2.55 ± 0.009).Decoupling analysis of the measured light absorption coefficients demonstrates that,on average,the light absorptions caused by dust aerosol and BC make up about 50.5% and 49.5% respectively of the total light absorption at 520 nm; during dust weather process periods (dust storm,floating dust,blowing dust),the contribution of dust aerosol to absorption extinction is 60.6% on average; in the hinterland of desert in spring,dust aerosol is also the major contributor to the total aerosol light absorption,more than that of black carbon aerosol.

  5. Development of KASI Geomagnetic Storm Forecast System using Coronagraph Data

    Science.gov (United States)

    Baek, Ji-Hye; Choi, SeongHwan; Park, Jongyeob; Kim, Roksoon; Kim, Sujin; Kim, Jihun

    2017-08-01

    We present Korea Astronomy and Space Science Institute (KASI) Geomagnetic Storm Forecast System. The aim of the system is to calculate the CME arrival time and predict the geoeffectiveness of the CME. To implement the system, we use the Large Angle and Spectrometric Coronagraph (LASCO) C2 and C3 data, the HMI magnetogram data of Solar Dynamics Observatory(SDO), and CACTUS CME list. The system consists of servers, which are to download, process, and publish data, data handling programs and web service. We apply an image differencing technique on LASCO data to determine speed and earthward direction parameters of CMEs. KASI Geomagnetic Storm Forecast Model has installed and being tested at Community Coordinated Modeling Center (CCMC) of NASA/GSFC. We expect that users can predict CME arrival time and geoeffectiveness of the CME easily and fast using the system. In order to improve the forecast performance of the system, we plan to incorporate advanced coronagraph data which will be developed and installed on ISS by KASI and NASA in collaboration.

  6. Comparison of Dst Forecast Models for Intense Geomagnetic Storms

    Science.gov (United States)

    Ji, Eun-Young; Moon, Y.-J.; Gopalswamy, N.; Lee, D.-H.

    2012-01-01

    We have compared six disturbance storm time (Dst) forecast models using 63 intense geomagnetic storms (Dst Dst data and the predicted Dst during the geomagnetic storm period as well as the difference of the value of minimum Dst (Delta Dst(sub min)) and the difference in the absolute value of Dst minimum time (Delta t(sub Dst)) between the observed and the predicted. As a result, we found that the model by Temerin and Li gives the best prediction for all parameters when all 63 events are considered. The model gives the average values: the linear correlation coefficient of 0.94, the RMS error of 14.8 nT, the Delta Dst(sub min) of 7.7 nT, and the absolute value of Delta t(sub Dst) of 1.5 hour. For further comparison, we classified the storm events into two groups according to the magnitude of Dst. We found that the model of Temerin and Lee is better than the other models for the events having 100 Dst Dst <= 200 nT.

  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. Aircraft-based observations and high-resolution simulations of an Icelandic dust storm

    Directory of Open Access Journals (Sweden)

    A.-M. Blechschmidt

    2012-11-01

    Full Text Available The first aircraft-based observations of an Icelandic dust storm are presented. The measurements were carried out over the ocean near Iceland's south coast in February 2007. This dust event occurred in conjunction with an easterly barrier jet of more than 30 m s−1. The aircraft measurements show high particle mass mixing ratios in an area of low wind speeds in the wake of Iceland near the coast, decreasing abruptly towards the jet. Simulations from the Weather Research and Forecasting Model coupled with Chemistry (WRF/Chem indicate that the measured high mass mixing ratios and observed low visibility inside the wake are due to dust transported from Icelandic sand fields towards the ocean. This is confirmed by meteorological station data. Glacial outwash terrains located near the Mýrdalsjökull glacier are among simulated dust sources. Sea salt aerosols produced by the impact of strong winds on the ocean surface started to dominate as the aircraft flew away from Iceland into the jet. The present results support recent studies which suggest that Icelandic deserts should be considered as important dust sources in global and regional climate models.

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

    Science.gov (United States)

    Gat, Daniella; Mazar, Yinon; Cytryn, Eddie; Rudich, Yinon

    2017-06-20

    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: Rehovot, Israel. Storms from different dust origins exhibited distinct bacterial communities, with signature bacterial taxa. 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 and possibly anthropogenic. With the progression of the storm, the storm-borne bacterial community showed increasing resemblance to ambient dust, suggesting mixing with local dust. These results show, for the first time, that dust storms from different sources display distinct bacterial communities, suggesting possible diverse effects on the environment and public health.

  10. The impact of dust on sulfate aerosol, CN and CCN during an East Asian dust storm

    Science.gov (United States)

    Manktelow, P. T.; Carslaw, K. S.; Mann, G. W.; Spracklen, D. V.

    2010-01-01

    A global model of aerosol microphysics is used to simulate a large East Asian dust storm during the ACE-Asia experiment. We use the model together with size resolved measurements of aerosol number concentration and composition to examine how dust modified the production of sulfate aerosol and the particle size distribution in East Asian outflow. Simulated size distributions and mass concentrations of dust, sub- and super-micron sulfate agree well with observations from the C-130 aircraft. Modeled mass concentrations of fine sulfate (Dp1.0 μm) by more than an order of magnitude, but total sulfate concentrations increase by less than 2% because decreases in fine sulfate have a compensating effect. Our analysis shows that the sulfate associated with dust can be explained largely by the uptake of H2SO4 rather than reaction of SO2 on the dust surface, which we assume is suppressed once the particles are coated in sulfate. We suggest that many previous model investigations significantly overestimated SO2 oxidation on East Asian dust, possibly due to the neglect of surface saturation effects. We extend previous model experiments by examining how dust modified existing particle concentrations in Asian outflow. Total particle concentrations (condensation nuclei, CN) modeled in the dust-pollution plume are reduced by up to 20%, but we predict that dust led to less than 10% depletion in particles large enough to act as cloud condensation nuclei (CCN). Our analysis suggests that E. Asian dust storms have only a minor impact on sulfate particles present at climate-relevant sizes.

  11. 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) and a Dst model developed by Temerin and Li (2002, 2006) (TL model). Using 55 CME-Dst pairs during 1997 to 2003, our solar wind criteria produce slightly better forecasts for 31 storm events (90%) than the forecasts based on the TL model (87%). However, the latter produces better forecasts for 24 nonstorm events (88%), while the former correctly forecasts only 71% 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%) can be properly predicted based on solar wind conditions; (ii) if we forecast a storm when both CME and solar wind conditions are satisfied (∩), the critical success index becomes higher than that from the forecast using CME parameters alone, however, only 25 storm events (81%) are correctly forecasted; and (iii) if we forecast a storm when either set of these conditions is satisfied (∪), all geomagnetic storms are correctly forecasted. PMID:26213515

  12. Climate Change Implications and Use of Early Warning Systems for Global Dust Storms

    Science.gov (United States)

    Harriman, L.

    2014-12-01

    Increased changes in land cover and global climate have led to increased frequency and/or intensity of dust storms in some regions of the world. 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 to people and the environment. Since frequency and intensity of dust storms can vary from region to region, there is a demonstrated need for more research to be conducted over longer periods of time to analyze trends of dust storm events [1]. Dust storms impact their origin area, but also land, water and people a great distance away from where dust finally settles [2, 3]. These transboundary movements and accompanying impacts further warrant the need for global collaboration to help predict the onset, duration and path of a dust storm. Early warning systems can help communicate when a dust storm is occurring, the projected intensity of the dust storm and its anticipated physical impact over a particular geographic area. Development of regional dust storm models, such as CUACE/Dust for East Asia, and monitoring networks, like the Sand and Dust Storm Warning Network operated by the World Meteorological Organization, and the use of remote sensing and satellite imagery derived products [4], including MODIS, are currently being incorporated into early warning and monitoring initiatives. However, to increase future certainty of impacts of dust storms on vulnerable populations and ecosystems, more research is needed to analyze the influences of human activities, seasonal variations and long-term climatic patterns on dust storm generation, movement and impact. Sources: [1] Goudie, A.S. (2009), Dust storms: recent developments, J Environ. Manage., 90. [2] Lee, H., and Liu, C. (2004), Coping with dust storm events: information, impacts, and policymaking in Taiwan, TAO, 15(5). [3] Marx, S.K., McGowan, H.A., and Balz, K.S. (2009), Long-range dust

  13. The Association between Dust Storms and Daily Non-Accidental Mortality in the United States, 1993-2005.

    Science.gov (United States)

    Background:The impact of dust storms on human health has been studied in the context of Asian,Saharan, Arabian, and Australian storms,but there has been no recent population-level epidemiological research on the dust storms in North America . The relevance of dust storms to publi...

  14. Analysis of the severe group dust storms in eastern part of Northwest China

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Based on the available original dust storm records from 60 meteorological stations, we discussed the identification standard of severe dust storms at a single station and constructed a quite complete time series of severe group dust storms in the eastern part of Northwest China in 1954-2001.The result shows that there were 99 severe group dust storms in this region in recent 48 years. The spatial distribution indicates that the Alax Plateau, most parts of the Ordos Plateau and most parts of the Hexi Corridor are the main areas influenced by severe group dust storms. In addition, the seasonand the month with the most frequent severe group dust storms are spring and April, accounting for 78.8% and 41.4% of the total events respectively. During the past 48 years the lowest rate of severe group dust storms occurred in the 1990s. Compared with the other 4 decades, on the average, the duration and the affected area of severe group dust storms are relatively short and small during the 1990s. In 2000 and 2001, there were separately 4 severe group dust storms as the higher value after 1983 in the eastern part of Northwest China.

  15. Operations Strategies for the Mars Exploration Rovers During the 2007 Martian Global Dust Storm

    Science.gov (United States)

    Seibert, Michael; Herman, Jennifer; ElDeeb, Dina

    2009-01-01

    In June and July 2007 Mars experienced a dust storm that grew to envelop all but the polar latitudes of the planet. This dust storm was the first global dust storm to occur while the twin Mars Exploration Rovers (MER) began surface operations. It is estimated that the dust in the atmosphere prevented over 99.6% of direct sunlight from reaching the surface at the peak of the storm. Data collected indicated that solar array energy output was reduced to approximately 15% of maximum. The reduction in insolation and energy output posed the greatest risk of ending the mission for both rovers at that time.

  16. Retrieval of dust storm aerosols using an integrated Neural Network model

    Science.gov (United States)

    Xiao, Fei; Wong, Man Sing; Lee, Kwon Ho; Campbell, James R.; Shea, Yu-kai

    2015-12-01

    Dust storms are known to have adverse effects on public health. Atmospheric dust loading is also one of the major uncertainties in global climatic modeling as it is known to have a significant impact on the radiation budget and atmospheric stability. This study develops an integrated model for dust storm detection and retrieval based on the combination of geostationary satellite images and forward trajectory model. The proposed model consists of three components: (i) a Neural Network (NN) model for near real-time detection of dust storms; (ii) a NN model for dust Aerosol Optical Thickness (AOT) retrieval; and (iii) the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model to analyze the transports of dust storms. These three components are combined using an event-driven active geo-processing workflow technique. The NN models were trained for the dust detection and validated using sunphotometer measurements from the AErosol RObotic NETwork (AERONET). The HYSPLIT model was applied in the regions with high probabilities of dust locations, and simulated the transport pathways of dust storms. This newly automated hybrid method can be used to give advance near real-time warning of dust storms, for both environmental authorities and public. The proposed methodology can be applied on early warning of adverse air quality conditions, and prediction of low visibility associated with dust storm events for port and airport authorities.

  17. An electrified dust storm over the Negev desert, Israel

    Science.gov (United States)

    Yair, Yoav; Katz, Shai; Yaniv, Roy; Ziv, Baruch; Price, Colin

    2016-11-01

    We report on atmospheric electrical measurements conducted at the Wise Observatory in Mitzpe-Ramon, Israel (30°35‧N, 34°45‧E) during a large dust storm that occurred over the Eastern Mediterranean region on 10-11 February 2015. The dust was transported from the Sahara, Egypt and the Sinai Peninsula ahead of an approaching Cyprus low. Satellite images show the dust plume covering the Negev desert and Southern Israel and moving north. The concentrations of PM10 particles measured by the air-quality monitoring network of the Israeli Ministry of the Environment in Beer-Sheba reached values > 450 μg m- 3 and the AOT from the AERONET station in Sde-Boker was 1.5 on February 10th. The gradual intensification of the event reached peak concentrations on February 11th of over 1200 μg m- 3 and an AOT of 1.8. Continuous measurements of the fair weather vertical electric field (Ez) and vertical current density (Jz) were conducted at the Wise Observatory with 1 minute temporal resolution. Meteorological data was also recorded at the site. As the dust was advected over the observatory, very large fluctuations in the electrical parameters were registered. From the onset of the dust storm, the Ez values changed between + 1000 and + 8000 V m- 1 while the current density fluctuated between - 10 pA m2 and + 20 pA m2, both on time-scales of a few minutes. These values are significant departures from the average fair-weather values measured at the site, which are ~- 200 V m- 1 and ~ 2 pA m2. The disturbed episodes lasted for several hours on February 10th and the 11th and coincided with local meteorological conditions related to the wind speed and direction, which carried large amounts of dust particles over our observation station. We interpret the rapid changes as caused by the transport of electrically charged dust, carrying an excess of negative charge at lower altitudes.

  18. Evaluation of the electrical properties of dust storms by multi-parameter observations and theoretical calculations

    Science.gov (United States)

    Zhang, Huan; Bo, Tian-Li; Zheng, Xiaojing

    2017-03-01

    Dusty phenomena, such as wind-blown sand, dust devils, and dust storms, play key roles in Earth's climate and geological processes. Dust electrification considerably affects the lifting and transport of dust particles. However, the electrical properties of dust storms remain poorly understood. Here, we conducted multi-parameter measurements and theoretical calculations to investigate the electrical properties of dust storms and their application to dust storm prediction. The results show that the vertical electric field (E-field) decreases first, then increases, and finally decreases with the height above the ground, reversing its direction at two heights, ∼ 8- 12 and ∼ 24 m. This suggests that the charge polarity of dust particles changes from negative to positive and back to negative again as the height increases. By carefully analyzing the E-field and dust concentration data, we further found that there is a significant positive linear relationship between the measured E-field intensity and dust concentration at the given ambient conditions. In addition, measurements and calculations demonstrate that a substantial enhancement in the vertical E-field can be observed several hours before the arrival of the external-source dust storms, indicating that the E-field can be used to provide an early warning of external-source dust storms.

  19. Variation of strong dust storm events in Northern China during 1978-2007

    Science.gov (United States)

    Wang, Ruxing; Liu, Bo; Li, Huiru; Zou, Xueyong; Wang, Jingpu; Liu, Wei; Cheng, Hong; Kang, Liqiang; Zhang, Chunlai

    2017-01-01

    Dust storms have a great significance for global mineral aerosol cycle, marine ecosystem, air quality and human health. Dust storm frequency (DSF), often used as a primary index for understanding a regional characteristic of dust storms. However, DSF couldn't describe the frequency and the outbreak areas of a dust storm event (DSE) which was defined as a dust storm occurred at three or more meteorological stations during the same weather process, because a DSE might occur at several meteorological stations and continue for several days. We defined a new index DSE considering the factors including wind speed, wind direction and spatial variation during a dust storm process. To clarify which index of DSF or DSE is better to describe the characteristics of dust storms, we have used the data sets of dust storm from 319 meteorological stations to calculate the frequency of DSE, and the outbreak area and the duration of each DSE in 1978-2007, as well as to compare the differences between DSE and DSF in spatiotemporal distribution in Northern China. The results showed that the high-value locations of occurrence numbers of DSE and DSF were almost overlapped; from 1978 to 2007, the total values of DSE and DSF decreased from 558 to 201 and from 1273 to 467, respectively, but the mean values of outbreak area and duration of DSE have wavily increased since 1991. These implied that the differences existed between DSE and DSF in describing the characteristics of a regional dust storm, and DSE was a better index for a dust storm to identify the fact of occurrence frequency and outbreak area. The implication of this study was that the values of DSE and DSF have a decrease trends with increase of extreme precipitation events and decrease of mean wind speed under the global warming scenarios, but strong dust storms, which is defined as the outbreak area of an event > 105 km2 here, probably bring greater risk in future.

  20. Simulation of the Radiative Impact of High Dust Loading during a Dust Storm in March 2012

    Science.gov (United States)

    Puthan Purakkal, J.; Kalenderski, S.; Stenchikov, G. L.

    2013-12-01

    We investigated a severe dust storm that developed over vast areas of the Middle East on 18-19 March 2012 and affected Saudi Arabia, Sudan, Egypt, Jordan, United Arab Emirates, Bahrain, Qatar, Oman, Kuwait, Iraq, Iran, Israel, and Pakistan. The visible aerosol optical depth recorded by the AERONET station on the KAUST campus (22.30o N 39.10o E) during the storm reached 4.5, exceeding the average level by an order of magnitude. To quantify the effects of the dust on atmospheric radiation and dynamics, we analyzed available ground-based and satellite observations and conducted numerical simulations using a fully coupled meteorology-chemistry-aerosol model (WRF-Chem). The model was able to reproduce the spatial and temporal patterns of the aerosol optical depths (AOD) observed by airborne and ground-based instruments. The major dust sources included river valleys of lower Tigris and Euphrates in Iraq, desert areas in Kuwait, Iran, United Arab Emirates, central Arabia including Rub' al Khali, An Nafud, and Ad Dahna, as well as the Red Sea coast of the Arabian Peninsula. The total amount of dust generated across the entire domain during the period of the simulation reached 93.76 Mt; 73.04 Mt of dust was deposited within the domain; 6.56 Mt of dust sunk in the adjacent sea waters, including 1.20 Mt that sedimented into the Red Sea. The model predicted a well-mixed boundary layer expanding up to 3.5 km in the afternoon. Some dust plumes were seen above the Planetary Boundary layer. In our simulations, mineral dust heated the lower atmosphere with a maximum heating rate of 9 K/day. The dust storm reduced the downwelling shortwave radiation at the surface to a maximum daily average value of -134 Wm-2 and the daily averaged long-wave forcing at the surface increased to 43 Wm-2. The combined short-wave cooling and long-wave warming effects of dust aerosols caused significant reduction in the surface air temperature -6.7 K at 1200 UTC on 19 March 2013.

  1. Forecasting the northern African dust outbreak towards Europe in April 2011: a model intercomparison

    Science.gov (United States)

    Huneeus, N.; Basart, S.; Fiedler, S.; Morcrette, J.-J.; Benedetti, A.; Mulcahy, J.; Terradellas, E.; Pérez García-Pando, C.; Pejanovic, G.; Nickovic, S.; Arsenovic, P.; Schulz, M.; Cuevas, E.; Baldasano, J. M.; Pey, J.; Remy, S.; Cvetkovic, B.

    2016-04-01

    In the framework of the World Meteorological Organisation's Sand and Dust Storm Warning Advisory and Assessment System, we evaluated the predictions of five state-of-the-art dust forecast models during an intense Saharan dust outbreak affecting western and northern Europe in April 2011. We assessed the capacity of the models to predict the evolution of the dust cloud with lead times of up to 72 h using observations of aerosol optical depth (AOD) from the AErosol RObotic NETwork (AERONET) and the Moderate Resolution Imaging Spectroradiometer (MODIS) and dust surface concentrations from a ground-based measurement network. In addition, the predicted vertical dust distribution was evaluated with vertical extinction profiles from the Cloud and Aerosol Lidar with Orthogonal Polarization (CALIOP). To assess the diversity in forecast capability among the models, the analysis was extended to wind field (both surface and profile), synoptic conditions, emissions and deposition fluxes. Models predict the onset and evolution of the AOD for all analysed lead times. On average, differences among the models are larger than differences among lead times for each individual model. In spite of large differences in emission and deposition, the models present comparable skill for AOD. In general, models are better in predicting AOD than near-surface dust concentration over the Iberian Peninsula. Models tend to underestimate the long-range transport towards northern Europe. Our analysis suggests that this is partly due to difficulties in simulating the vertical distribution dust and horizontal wind. Differences in the size distribution and wet scavenging efficiency may also account for model diversity in long-range transport.

  2. Forecasting the North African dust outbreak towards Europe in April 2011: a model intercomparison

    Science.gov (United States)

    Huneeus, N.; Basart, S.; Fiedler, S.; Morcrette, J.-J.; Benedetti, A.; Mulcahy, J.; Terradellas, E.; Pérez García-Pando, C.; Pejanovic, G.; Nickovic, S.; Arsenovic, P.; Schulz, M.; Cuevas, E.; Baldasano, J. M.; Pey, J.; Remy, S.; Cvetkovic, B.

    2015-10-01

    In the framework of the World Meteorological Organisation's Sand and Dust Storm Warning Advisory and Assessment System, we evaluated the predictions of five state-of-the-art dust forecast models during an intense Saharan dust outbreak affecting Western and Northern Europe in April 2011. We assessed the capacity of the models to predict the evolution of the dust cloud with lead-times of up to 72 h using observations of aerosol optical depth (AOD) from the Aerosol Robotic Network (AERONET) and the Moderate Resolution Imaging Spectroradiometer (MODIS), and dust surface concentrations from a ground-based measurement network. In addition, the predicted vertical dust distribution was evaluated with vertical extinction profiles from the Cloud and Aerosol Lidar with Orthogonal Polarization (CALIOP). To assess the diversity in forecast capability among the models, the analysis was extended to wind field (both surface and profile), synoptic conditions, emissions and deposition fluxes. Models predict the onset and evolution of the AOD for all analysed lead-times. On average, differences among the models are larger than differences among lead-times for each individual model. In spite of large differences in emission and deposition, the models present comparable skill for AOD. In general, models are better in predicting AOD than near-surface dust concentration over the Iberian Peninsula. Models tend to underestimate the long-range transport towards Northern Europe. Our analysis suggests that this is partly due to difficulties in simulating the vertical distribution dust and horizontal wind. Differences in the size distribution and wet scavenging efficiency may also account for model diversity in long-range transport.

  3. Forecasting the Northern African Dust Outbreak Towards Europe in April 2011: A Model Intercomparison

    Science.gov (United States)

    Huneeus, N.; Basart, S.; Fiedler, S.; Morcrette, J.-J.; Benedetti, A.; Mulcahy, J.; Terradellas, E.; Pérez García-Pando, C.; Pejanovic, G.; Nickovic, S.

    2016-01-01

    In the framework of the World Meteorological Organisation's Sand and Dust Storm Warning Advisory and Assessment System, we evaluated the predictions of five state-of-the-art dust forecast models during an intense Saharan dust outbreak affecting western and northern Europe in April 2011. We assessed the capacity of the models to predict the evolution of the dust cloud with lead times of up to 72 hours using observations of aerosol optical depth (AOD) from the AErosol RObotic NETwork (AERONET) and the Moderate Resolution Imaging Spectroradiometer (MODIS) and dust surface concentrations from a ground-based measurement network. In addition, the predicted vertical dust distribution was evaluated with vertical extinction profiles from the Cloud and Aerosol Lidar with Orthogonal Polarization (CALIOP). To assess the diversity in forecast capability among the models, the analysis was extended to wind field (both surface and profile), synoptic conditions, emissions and deposition fluxes. Models predict the onset and evolution of the AOD for all analysed lead times. On average, differences among the models are larger than differences among lead times for each individual model. In spite of large differences in emission and deposition, the models present comparable skill for AOD. In general, models are better in predicting AOD than near-surface dust concentration over the Iberian Peninsula. Models tend to underestimate the long-range transport towards northern Europe. Our analysis suggests that this is partly due to difficulties in simulating the vertical distribution dust and horizontal wind. Differences in the size distribution and wet scavenging efficiency may also account for model diversity in long-range transport.

  4. Forecasting the North African dust outbreak towards Europe in April 2011: a model intercomparison

    Directory of Open Access Journals (Sweden)

    N. Huneeus

    2015-10-01

    Full Text Available In the framework of the World Meteorological Organisation's Sand and Dust Storm Warning Advisory and Assessment System, we evaluated the predictions of five state-of-the-art dust forecast models during an intense Saharan dust outbreak affecting Western and Northern Europe in April 2011. We assessed the capacity of the models to predict the evolution of the dust cloud with lead-times of up to 72 h using observations of aerosol optical depth (AOD from the Aerosol Robotic Network (AERONET and the Moderate Resolution Imaging Spectroradiometer (MODIS, and dust surface concentrations from a ground-based measurement network. In addition, the predicted vertical dust distribution was evaluated with vertical extinction profiles from the Cloud and Aerosol Lidar with Orthogonal Polarization (CALIOP. To assess the diversity in forecast capability among the models, the analysis was extended to wind field (both surface and profile, synoptic conditions, emissions and deposition fluxes. Models predict the onset and evolution of the AOD for all analysed lead-times. On average, differences among the models are larger than differences among lead-times for each individual model. In spite of large differences in emission and deposition, the models present comparable skill for AOD. In general, models are better in predicting AOD than near-surface dust concentration over the Iberian Peninsula. Models tend to underestimate the long-range transport towards Northern Europe. Our analysis suggests that this is partly due to difficulties in simulating the vertical distribution dust and horizontal wind. Differences in the size distribution and wet scavenging efficiency may also account for model diversity in long-range transport.

  5. The threat of Asian dust storms on asthma patients: a population-based study in Taiwan.

    Science.gov (United States)

    Wang, Chien-Ho; Chen, Chin-Shyan; Lin, Chung-Liang

    2014-01-01

    This study explores the relationship between Asian dust storms (ADSs), asthma hospital admissions and average medical cost discharge. We adopt the hospitalisation data from the Taiwan National Health Insurance research database covering the period from 2000 to 2009. The autoregressive integrated moving average with exogenous variables (ARIMAX) analyses were performed to explore the relationship between ADS and asthma hospital admissions, adjusting for temperature, air pollutants and season dummy. The results show that ADS events do generate a critical influence upon the occurrences of asthma on post-ADS events from days 1 through 3, with an average of 17-20 more hospitalised admissions, and have stronger effects on preschool children, middle-aged people and the elderly. From the perspective of medical expenses, the cost of hospitalised admissions for asthma substantially rises daily, on average, by NT$634,698 to NT$787,407 during ADS event days. This study suggests that government should establish a forecast and alert system and release warnings about dust storms, so that the individuals predisposed to asthma can take precautionary measures to reduce their outdoor exposure. Consequently, personal risk and medical expenditure could be reduced significantly, especially for preschool children, middle-aged people and the elderly with asthma.

  6. Characteristics of Meteorological Factors over Different Landscape Types During Dust Storm Events in Cele, Xinjiang, China

    Institute of Scientific and Technical Information of China (English)

    毛东雷; 雷加强; 李生宇; 曾凡江; 王翠; 周杰

    2014-01-01

    Landscape characteristics influence meteorological factors, thus affect the occurrence and nature of dust storm events. The present study investigates the spatiotemporal characteristics of six meteorological factors (wind velocity, wind direction, air temperature, relative humidity (RH), photo synthetically active radiation (PAR), and solar radiation) over different landscape types (shifting-sand frontier, semi-fixed sandy land, fixed sandy land, and the inner region of an oasis) before and after dust storms during four typical dust storm events in an oasis-desert ecotone in Cele, Xinjiang, China. The results show that the average wind velocity decreased significantly from the shifting-sand frontier to the inner oasis, which was mainly attributable to the vegetation coverage. Before the dust storm events, there were obvious differences in air temperature and RH either in the horizontal or vertical direction over the different landscape types. However, these factors were very similar during and following the dust storm events. PAR and solar radiation were significantly reduced during the dust storm events and the subsequent sand-blowing and floating-dust conditions. This effect was much stronger than during similar weather conditions without dust storm events such as sand-blowing and overcast and/or rainy days. Additionally, the variation in the meteorological factors among the different landscapes was also affected by the prevailing wind direction during the dust storm events. However, the landscape type slightly changed the prevailing wind direction, with the greatest dispersion distribution of wind direction in the inner oasis. The findings of this study are helpful for understanding the function of landscape types in the occurrence of dust storms, as well as for providing a theoretical basis for prevention of dust storms.

  7. Vulnerability Assessment of Dust Storms in the United States under a Changing Climate Scenario

    Science.gov (United States)

    Severe weather events, such as flooding, drought, forest fires, and dust storms can have a serious impact on human health. Dust storm events are not well predicted in the United States, however they are expected to become more frequent as global climate warms through the 21st cen...

  8. Dust Storms in the United States are Associated with Increased Cardiovascular Mortality

    Science.gov (United States)

    Background: Extreme weather events such as dust storms are predicted to become more frequent as the global climate warms through the 21st century. Studies of Asian, Saharan, Arabian, and Australian dust storms have found associations with cardiovascular and total non-accidental...

  9. Aerosol Properties Changes of Northeast Asia due to a Severe Dust Storm in April 2014

    Science.gov (United States)

    Fang, Li; Wang, Shupeng; Yu, Tao; Gu, Xingfa; Zhang, Xingying; Wang, Weihe; Ren, Suling

    2016-04-01

    This study focuses on analyzing the aerosol properties changes due to the dust storm named as "China's Great Wall of Dust" oriented from Taklimakan desert in April, 2014. Dust identification IDDI (Infrared Difference Dust Index) images from FY-2E and true color composite images from FY-3C MERSI (Medium Resolution Spectral Imager) show the breakout and transport of the dust storm.From 4-day forward air mass trajectories, the dusty air masses were mostly transported within the lower boundary layer(data records at surface stations suggest that anticyclonic circulation occupying southern Xinjiang basin and cyclonic circulation maintaining in Mongolia formed the typical Synoptic condition which leaded to the strong dust storm. Aerosol Index (AI) results of TOU (Total Ozone Unit) aboard FY-3B are first developed and used in studying the affected areas due to the dust storm. The retrieved aerosol indexes show sensitivity to the dust particles. The dust affected areas agree with the synoptic meteorological condition analysis, which prove the synoptic meteorological condition is the main reason for the break out and transport of the dust storm. Anomalies of the average MODIS (Moderate Resolution Imaging Spectroradiometer) AOD (Aerosol Optical Depth) distributions over Northeast Asia during the dust storm to the average of that in April between 2010-2014 show high aerosol loading due to the dust storm. Compared with the 5-year average AOD in April, aerosol loading during this dust storm was much higher, with AOD values at 550nm up to 2.9 observed over the northwest China.The dust storm also brought different change in the aerosol microphysical properties between Beijing and Dalanzadgad. Aerosol Robotic Network (AERONET) retrievals demonstrate that large amount of coarse particles were transported to Dalanzadgad by the dust storm, resulting in an obvious increase in the peak of coarse mode particles volume. The coarse dust particles increased the effective radius of the

  10. PRELIMINARY STUDY ON SAND—DUST STORM DISASTER AND COUNTERMEASURES IN CHINA

    Institute of Scientific and Technical Information of China (English)

    ZHANGQing-yang; ZHAOXi-you; 等

    2002-01-01

    As a kind of natural disasters,sand-dust storms frequently occur in deserts and their surrounding areas.The occurrence of this disaster in Chinaˊs north west and north china has exerted an extremely adverse effect upon the environ-ment in China.The management of sand-dust storms is of a systematic project closely related with the environment such as agriculture,ecosystem,forestry,water conservancy,meteorology and other aspects.Therefore,studies of the forma-tion,the basic eatures,causes,temporal-spatial distribution,developing-trend and related disasters of sand-dust storms in China are conducted based on satellite data.The experience of sand-dust storms control and countermeasures in the Unit-ed States and some other countries are referred.Meanwhile,preliminary countermeasures relating to sand-dust storms in China are proposed.

  11. Nivmar: a storm surge forecasting system for Spanish waters

    Directory of Open Access Journals (Sweden)

    Enrique Álvarez Fanjul

    2001-07-01

    Full Text Available In this paper, a storm surge prediction system for the Spanish Waters is presented. The system, named Nivmar, is based on the ocean circulation Hamsom model and on the harmonical prediction of tides computed from data measured by the tide gauge network Redmar, managed by Puertos del Estado. Nivmar is executed twice a day, running Hamsom forced by meteorological fields derived from the INM (Instituto Nacional de Meteorología operational application of Hirlam atmospheric model. Data from Redmar tide gauges is used to to forecast the tidal elevations, to validate the system and to perform data assimilation, correcting systematic errors in the mean sea level due to physicals processes that are not included in the ocean model (i. e. steric height. The forecast horizon is 48 hours. In order to validate the system with measured data from Redmar a very stormy 5 months period was selected. Results from this test (November 95 to March 96 are presented. Data from this experiment shown that Nivmar is able to correctly predict sea level in the region. A simple data assimilation scheme for sea level is described and results from its application are studied. Finally, special focus is made in future plans and potential developments and applications of the system.

  12. Atmospheric Electricity Effects of Eastern Mediterranean Dust Storms

    Science.gov (United States)

    Katz, Shai; Yair, Yoav; Yaniv, Roy; Price, Colin

    2016-04-01

    We present atmospheric electrical measurements conducted at the Wise Observatory (WO) in Mizpe-Ramon (30035'N, 34045'E) and Mt. Hermon (30024'N, 35051'E), Israel, during two massive and unique dust storms that occurred over the Eastern Mediterranean region on February 10-11 and September 08-12, 2015. The first event transported Saharan dust from Egypt and the Sinai Peninsula in advance of a warm front of a Cyprus low pressure system. In the second event, dust particles were transported from the Syrian desert, which dominates the north-east border with Iraq, through flow associated with a shallow Persian trough system. In both events the concentrations of PM10 particles measured by the air-quality monitoring network of the Israeli Ministry of the Environment in Beer-Sheba reached values > 2200 μg m-3. Aerosol Optical Thickness (AOT) obtained from the AERONET station in Sde-Boker reached values up to 4.0. The gradual intensification of the first event reached peak values on the February 11th > 1200 μg m-3 and an AOT ~ 1.8, while the second dust storm commenced on September 8th with a sharp increase reaching peak values of 2225 μg m-3 and AOT of 4.0. Measurements of the fair weather vertical electric field (Ez) and of the vertical current density (Jz) were conducted continuously with a 1 minute temporal resolution. During the February event, very large fluctuations in the electrical parameters were measured at the WO. The Ez values changed between +1000 and +8000 V m-1 while the Jz fluctuated between -10 and +20 pA m-2 (this is an order of magnitude larger compared to the fair weather current density of ~2 pA m-2. In contrast, during the September event, Ez values registered at WO were between -430 and +10 V m-1 while the Jz fluctuated between -6 and +3 pA m2. For the September event the Hermon site showed Ez and Jz values fluctuating between -460 and +570 V m-1 and -14.5 and +18 pA m-2 respectively. The electric field and current variability, amplitude and the

  13. Accurate and Timely Forecasting of CME-Driven Geomagnetic Storms

    Science.gov (United States)

    Chen, J.; Kunkel, V.; Skov, T. M.

    2015-12-01

    Wide-spread and severe geomagnetic storms are primarily caused by theejecta of coronal mass ejections (CMEs) that impose long durations ofstrong southward interplanetary magnetic field (IMF) on themagnetosphere, the duration and magnitude of the southward IMF (Bs)being the main determinants of geoeffectiveness. Another importantquantity to forecast is the arrival time of the expected geoeffectiveCME ejecta. In order to accurately forecast these quantities in atimely manner (say, 24--48 hours of advance warning time), it isnecessary to calculate the evolving CME ejecta---its structure andmagnetic field vector in three dimensions---using remote sensing solardata alone. We discuss a method based on the validated erupting fluxrope (EFR) model of CME dynamics. It has been shown using STEREO datathat the model can calculate the correct size, magnetic field, and theplasma parameters of a CME ejecta detected at 1 AU, using the observedCME position-time data alone as input (Kunkel and Chen 2010). Onedisparity is in the arrival time, which is attributed to thesimplified geometry of circular toroidal axis of the CME flux rope.Accordingly, the model has been extended to self-consistently includethe transverse expansion of the flux rope (Kunkel 2012; Kunkel andChen 2015). We show that the extended formulation provides a betterprediction of arrival time even if the CME apex does not propagatedirectly toward the earth. We apply the new method to a number of CMEevents and compare predicted flux ropes at 1 AU to the observed ejectastructures inferred from in situ magnetic and plasma data. The EFRmodel also predicts the asymptotic ambient solar wind speed (Vsw) foreach event, which has not been validated yet. The predicted Vswvalues are tested using the ENLIL model. We discuss the minimum andsufficient required input data for an operational forecasting systemfor predicting the drivers of large geomagnetic storms.Kunkel, V., and Chen, J., ApJ Lett, 715, L80, 2010. Kunkel, V., Ph

  14. Sand-dust storms in China: temporal-spatial distribution and tracks of source lands

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Sand-dust storm is a special natural disaster that frequentlyoccurs in deserts and their surrounding areas. With the data published on Surface Meteorological Monthly Bulletin and Surface Chart during 1971-1996, the temporal-spatial distribution and annual variation of sand-dust storms are analyzed on the basis of the case study of atmospheric processes. Furthermore, the tracks and source areas of sand-dust storms are determined with the aid of GIS. The results show that except some parts of Qinghai Province and Inner Mongolia as well as Beijing, sand-dust storms decrease apparently in time and space in recent decades in China. Sand-dust storms occur most frequently in spring, especially in April. According to their source areas, sand-dust storms are classified into two types, i.e., the inner-source and outer-source sand-dust storms. Most of the outer-source sand-dust storms move along the north and west tracks. The north-track outer-source sand-dust storms always intrude into China across the Sino-Mongolian border from Hami, a city in the eastern part of Xinjiang, to Xilin Gol, a league in Inner Mongolia, while the west-track ones intrude into China from both southern and northern Xinjiang. The source lands of inner-source sand-dust storms concentrate in the Taklimakan Desert and its surrounding areas in southern Xinjiang, southern part of the Junggar Basin in north of Xinjiang, the Hexi Corridor in western Gansu Province, the dry deserts of Inner Mongolia and the Qaidam Basin in Qinghai.

  15. Atmospheric bioaerosols transported via dust storms in the western United States

    Science.gov (United States)

    Hallar, A. Gannet; Chirokova, Galina; McCubbin, Ian; Painter, Thomas H.; Wiedinmyer, Christine; Dodson, Craig

    2011-09-01

    Measurements are presented showing the presence of biological material within frequent dust storms in the western United States. Previous work has indicated that biological particles were enhancing the impact of dust storms on the formation of clouds. This paper presents multiple case studies, between April and May 2010, showing the presence of and quantifying the amount of biological material via an Ultraviolet Aerodynamic Particle Sizer during dust events. All dust storms originated in the Four Corners region in the western Untied States and were measured at Storm Peak Laboratory, a high elevation facility in northwestern Colorado. From an Aerodynamic Particle Sizer, the mean dust particle size during these events was approximately 1 μm, with number concentrations between 6 cm-3 and 12 cm-3. Approximately 0.2% of these dust particles had fluorescence signatures, indicating the presence of biological material.

  16. 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

  17. Continuous Measurement of Number Concentrations and Elemental Composition of Aerosol Particles for a Dust Storm Event in Beijing

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A continuous measurement of number size distributions and chemical composition of aerosol particles was conducted in Beijing in a dust storm event during 21-26 March 2001. The number concentration of coarse particles (>2μm) increased more significantly than fine particles (<2μm) during the dust storm due to dust weather, while the anthropogenic aerosols collected during the non-dust-storm period tended to be associated with fine particles. Elemental compositions were analyzed by using proton-induced X-ray emission (PIXE). The results show that 20 elements in the dust storm were much higher than in the non-dust-storm period. The calculated soil dust concentration during the dust storm was, on average, 251.8μg m-3, while it was only 52.1 μg m-3 on non-dust-storm days. The enrichment factors for Mg, Al, P, K, Ca, Ti, Mn, Fe, Cl, Cu, Pb, and Zn show small variations between the dust storm and the non-dust-storm period, while those for Ca, Ni and Cr in the dust storm were much lower than those in the non-dust-storm period due to significant local emission sources. A high concentration and enrichment factor for S were observed during the dust storm, which implies that the dust particles were contaminated by aerosol particles from anthropogenic emissions during the long-range transport. A statistical analysis shows that the elemental composition of particles collected during the dust storm in Beijing were better correlated with those of desert soil colleted from desert regions in Inner Mongolia. Air mass back-trajectory analysis further confirmed that this dust storm event could be identified as streaks of dust plumes originating from Inner Mongolia.

  18. An automated and integrated framework for dust storm detection based on ogc web processing services

    OpenAIRE

    Xiao, F.; G. Y. K. Shea; Wong, M. S.; Campbell, J.

    2014-01-01

    Dust storms are known to have adverse effects on public health. Atmospheric dust loading is also one of the major uncertainties in global climatic modelling as it is known to have a significant impact on the radiation budget and atmospheric stability. The complexity of building scientific dust storm models is coupled with the scientific computation advancement, ongoing computing platform development, and the development of heterogeneous Earth Observation (EO) networks. It is a challe...

  19. Change in dust seasonality as the primary driver for orbital-scale dust storm variability in East Asia

    Science.gov (United States)

    Serno, Sascha; Winckler, Gisela; Anderson, Robert F.; Jaccard, Samuel L.; Kienast, Stephanie S.; Haug, Gerald H.

    2017-04-01

    Glacial periods are recognized to be dustier than interglacials, but the conditions leading to greater dust mobilization are poorly defined. Here we present a new high-resolution dust record based on 230Th-normalized 4He flux from Ocean Drilling Program site 882 in the Subarctic North Pacific covering the last 170,000 years. By analogy with modern relationships, we infer the mechanisms controlling orbital-scale dust storm variability in East Asia. We propose that orbital-scale dust flux variability is the result of an expansion of the dust season into summer, in addition to more intense dust storms during spring and fall. The primary drivers influencing dust flux include summer insolation at subarctic latitudes and variable Siberian alpine glaciation, which together control the cold air reservoir in Siberia. Changes in the extent of the Northern Hemisphere ice sheets may be a secondary control.

  20. Implementation and application of a nested numerical storm surge forecast model in the East China Sea

    Institute of Scientific and Technical Information of China (English)

    于福江; 张占海

    2002-01-01

    A nested numerical storm surge forecast model for the East China Sea is developed. A one-way relaxing nest method is used to exchange the information between coarse grid and fine grid. In the inner boundary of the fine grid model a transition area is set up to relax the forecast variables. This ensures that the forecast variables of the coarse model may transit to those of fine grid gradually, which enhances the model stability. By using this model, a number of hindcasts and forecast are performed for six severe storm surges caused by tropical cyclones in the East China Sea. The results show good agreement with the observations.

  1. Effects of two dust storms on solar radiation in the Beijing-Tianjin area

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, M.; Chen, Z.; Huang, R.; Wang, Q.; Arimoto, R.; Parungo, F.; Lenschow, D.; Okada, K.; Wu, P. [National Research Center for Marine Environm, Forecasts, Beijing (Taiwan, Province of China)]|[Univ. of Rhode Island, Narragansett, RI (United States)]|[NOAA, Boulder, CO (United States)]|[National Center for Atmospheric Research, Boulder, CO (United States)]|[Meteorological Research Inst., Tsukuba (Japan)

    1994-12-01

    Advanced Very High Resolution Radiometer (AVHRR) albedo data obtained from the NOAA-11 satellite and chemical data for aerosol particle samples collected in Beijing were intepreted together with meteorological data to study the radiative effects of Asian dust. Compared with the clea-sky background, the albedo values for the Beijing area during two dust storms in April 1993 increased by 20 to 125%; the direct solar radiation flux at the surface decreased; and the scattered radiation flux at the surface increased. The total solar radiation flux at the ground during the two dust storms decreased by 40% and 10% respectively. Furthermore, the extent of the changes was related to the strength of the dust storms. This paper demonstrates the feasibility of using satellite data to study the radiative forcing of dust storms.

  2. PRELIMINARY STUDY ON SAND-DUST STORM DISASTER AND COUNTERMEASURES IN CHINA

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    As a kind of natural disasters, sand-dust storms frequently occur in deserts and their surrounding areas.The occurrence of this disaster in China's northwest and north China has exerted an extremely adverse effect upon the environ-ment in China. The management of sand-dust storms is of a systematic project closely related with the environment suchas agriculture, ecosystem, forestry, water conservancy, meteorology and other aspects. Therefore, studies of the forma-tion, the basic features, causes, temporal-spatial distribution, developing-trend and related disasters of sand-dust stormsin China are conducted based on satellite data. The experience of sand-dust storms control and countermeasures in the Unit-ed States and some other countries are referred. Meanwhile, preliminary countermeasures relating to sand-dust storms inChina are proposed.

  3. Dust storms and the risk of asthma admissions to hospitals in Kuwait.

    Science.gov (United States)

    Thalib, Lukman; Al-Taiar, Abdullah

    2012-09-01

    Arid areas in the Arabian Peninsula are one of the largest sources of global dust, yet there is no data on the impact of this on human health. This study aimed to investigate the impact of dust storms on hospital admissions due to asthma and all respiratory diseases over a period of 5 years in Kuwait. A population-based retrospective time series study of daily emergency asthma admissions and admissions due to respiratory causes in public hospitals in Kuwait was analyzed in relation to dust storm events. Dust storm days were defined as the mean daily PM(10)>200 μg/m(3) based on measurements obtained from all six monitoring sites in the country. During the five-year study period, 569 (33.6%) days had dust storm events and they were significantly associated with an increased risk of same-day asthma and respiratory admission, adjusted relative risk of 1.07 (95% CI: 1.02-1.12) and 1.06 (95% CI: 1.04-1.08), respectively. This was particularly evident among children. Dust storms have a significant impact on respiratory and asthma admissions. Evidence is more convincing and robust compared to that from other geographical settings which highlights the importance of public health measures to protect people's health during dust storms and reduce the burden on health services due to dust events. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Data Assimilation within the Advanced Circulation (ADCIRC) Modeling Framework for Hurricane Storm Surge Forecasting

    KAUST Repository

    Butler, T.

    2012-07-01

    Accurate, real-time forecasting of coastal inundation due to hurricanes and tropical storms is a challenging computational problem requiring high-fidelity forward models of currents and water levels driven by hurricane-force winds. Despite best efforts in computational modeling there will always be uncertainty in storm surge forecasts. In recent years, there has been significant instrumentation located along the coastal United States for the purpose of collecting data—specifically wind, water levels, and wave heights—during these extreme events. This type of data, if available in real time, could be used in a data assimilation framework to improve hurricane storm surge forecasts. In this paper a data assimilation methodology for storm surge forecasting based on the use of ensemble Kalman filters and the advanced circulation (ADCIRC) storm surge model is described. The singular evolutive interpolated Kalman (SEIK) filter has been shown to be effective at producing accurate results for ocean models using small ensemble sizes initialized by an empirical orthogonal function analysis. The SEIK filter is applied to the ADCIRC model to improve storm surge forecasting, particularly in capturing maximum water levels (high water marks) and the timing of the surge. Two test cases of data obtained from hindcast studies of Hurricanes Ike and Katrina are presented. It is shown that a modified SEIK filter with an inflation factor improves the accuracy of coarse-resolution forecasts of storm surge resulting from hurricanes. Furthermore, the SEIK filter requires only modest computational resources to obtain more accurate forecasts of storm surge in a constrained time window where forecasters must interact with emergency responders.

  5. Sand-dust Storm,Population and Environment in Northwest China

    Institute of Scientific and Technical Information of China (English)

    Liu Shao

    2004-01-01

    Sand-dust storms are the result of the integrated influences of climate, geography, society and human factors. A theoretical framework is built to explain the coherence of population growth,agriculture change and environmental degradation.On the basis of the analysis of the causes of the sand-dust storm in terms of human factors, a discussion will be given to show that these factors are internally consistent with the theoretical framework. After that, it will look at Chinas Agenda21 and try to find relevant measures to reduce such large sand-dust storms happening in Northwest China and eventually make this area develop sustainably.

  6. Physicochemistry and Mineralogy of Storm Dust and Dust Sediment in Northern China

    Institute of Scientific and Technical Information of China (English)

    刘蔚; 冯起; 王涛; 张艳武; 施建华

    2004-01-01

    Dust sediments collected from 1995 to 1998 in Beijing, Dunhuang, Inner Mongolia, Kashi, the Kunlun Mountains, Lanzhou, Ningxia, the Taklimakan Desert, and Xi'an, China, were characterized in terms of their physical, chemical, and mineralogical properties. Most aerosols and dust analysed ranged in texture from silty clay to clay loam. Their median particle diameters (Mds) generally ranged between 5 to 63μm,coinciding with those of loess from central China and the finest sand from northwestern China. The dust sediments were characterized by a predominance of SiO2 and Al2O3, followed by K2O. Their SiO2/Al2O3and K2O/SiO2 molar ratios ranged from 5.17 to 8.43 and from 0.009 to 0.0368, respectively. The mass concentration spectrum during a dust storm showed a single peak, rather than the triple peak generally observed under clear sky conditions. The dominant minerals were chlorite, illite, calcite, and dolomite.These physical, chemical, and mineralogical properties were consistent with those of aeolian soils and loess in western and central China. The results suggest that aerosols and fine-gained fractions of dust sediments collected in northern China are mainly composed of soil material transported from the arid and semiarid regions of China and Mongolia by prevailing winds. The rate of deposition and properties of dust falling on eastern China were strongly influenced by meteorological conditions, season, latitude, longitude, and altitude of the sampling sites.

  7. Dust and Air Quality Forecasting in the Eastern Caribbean

    Science.gov (United States)

    Sealy, A. M.; Reyes, A.; Farrell, D. A.

    2015-12-01

    Significant amounts of dust travel across the northern tropical Atlantic to the Caribbean every year from the Sahara region. These dust concentrations in the Caribbean often exceed United States Environmental Protection Agency (EPA) standards for particulate matter of 2.5 microns or less (PM 2.5) which could have serious implications for human health in the region. Air pollution has become a major issue in the Caribbean because of urban development, increased vehicle emissions and growing industrialisation. However, the majority of territories in the Caribbean do not have routine air quality monitoring programmes and several do not have or enforce air quality standards for PM2.5 and PM10. As a result, the Caribbean Institute for Meteorology and Hydrology (CIMH) has taken the initiative to provide dust and air quality forecasts for the Eastern Caribbean using the advanced WRF-Chem modeling system. The applications of the WRF-Chem modelling system at CIMH that are currently being focused on are the coupled weather prediction/dispersion model to simulate the release and transport of constituents, especially Saharan dust transport and concentration; and as a coupled weather/dispersion/air quality model with full interaction of chemical species with prediction of particulate matter (PM2.5 and PM10). This will include future applications in the prediction of ozone (O3) and ultraviolet (UV) radiation as well as examining dust radiative forcing and effects on atmospheric precipitation and dynamics. The simulations are currently initialised at 00Z for a seven day forecast and run at 36 km resolution with a planned second domain (at 12 km) for air quality forecasts. Preliminary results from this study will be presented and compared to other dust forecast models currently used in other regions. This work also complements in situ measurements at Ragged Point, Barbados (oldest dust record since 1965), Martinique, Guadeloupe, French Guiana and Puerto Rico. The goal of this study

  8. An automated and integrated framework for dust storm detection based on ogc web processing services

    Science.gov (United States)

    Xiao, F.; Shea, G. Y. K.; Wong, M. S.; Campbell, J.

    2014-11-01

    Dust storms are known to have adverse effects on public health. Atmospheric dust loading is also one of the major uncertainties in global climatic modelling as it is known to have a significant impact on the radiation budget and atmospheric stability. The complexity of building scientific dust storm models is coupled with the scientific computation advancement, ongoing computing platform development, and the development of heterogeneous Earth Observation (EO) networks. It is a challenging task to develop an integrated and automated scheme for dust storm detection that combines Geo-Processing frameworks, scientific models and EO data together to enable the dust storm detection and tracking processes in a dynamic and timely manner. This study develops an automated and integrated framework for dust storm detection and tracking based on the Web Processing Services (WPS) initiated by Open Geospatial Consortium (OGC). The presented WPS framework consists of EO data retrieval components, dust storm detecting and tracking component, and service chain orchestration engine. The EO data processing component is implemented based on OPeNDAP standard. The dust storm detecting and tracking component combines three earth scientific models, which are SBDART model (for computing aerosol optical depth (AOT) of dust particles), WRF model (for simulating meteorological parameters) and HYSPLIT model (for simulating the dust storm transport processes). The service chain orchestration engine is implemented based on Business Process Execution Language for Web Service (BPEL4WS) using open-source software. The output results, including horizontal and vertical AOT distribution of dust particles as well as their transport paths, were represented using KML/XML and displayed in Google Earth. A serious dust storm, which occurred over East Asia from 26 to 28 Apr 2012, is used to test the applicability of the proposed WPS framework. Our aim here is to solve a specific instance of a complex EO data

  9. Intensified dust storm activity and Valley fever infection in the southwestern United States

    Science.gov (United States)

    Tong, Daniel Q.; Wang, Julian X. L.; Gill, Thomas E.; Lei, Hang; Wang, Binyu

    2017-05-01

    Climate models have consistently projected a drying trend in the southwestern United States, aiding speculation of increasing dust storms in this region. Long-term climatology is essential to documenting the dust trend and its response to climate variability. We have reconstructed long-term dust climatology in the western United States, based on a comprehensive dust identification method and continuous aerosol observations from the Interagency Monitoring of Protected Visual Environments (IMPROVE) network. We report here direct evidence of rapid intensification of dust storm activity over American deserts in the past decades (1988-2011), in contrast to reported decreasing trends in Asia and Africa. The frequency of windblown dust storms has increased 240% from 1990s to 2000s. This dust trend is associated with large-scale variations of sea surface temperature in the Pacific Ocean, with the strongest correlation with the Pacific Decadal Oscillation. We further investigate the relationship between dust and Valley fever, a fast-rising infectious disease caused by inhaling soil-dwelling fungus (Coccidioides immitis and C. posadasii) in the southwestern United States. The frequency of dust storms is found to be correlated with Valley fever incidences, with a coefficient (r) comparable to or stronger than that with other factors believed to control the disease in two endemic centers (Maricopa and Pima County, Arizona).

  10. Enhancement of oceanic parameters associated with dust storms using satellite data

    Science.gov (United States)

    Singh, Ramesh P.; Prasad, Anup K.; Kayetha, Vinay K.; Kafatos, Menas

    2008-11-01

    Atmospheric aerosols play a vital role on the dynamics of climate processes through direct and indirect effects. Dust storms originating over the world's arid regions contribute a large fraction of aerosols in the atmosphere. Using remote sensing data, an anomalous enhancement in the biological productivity of sea was observed in the Gulf of Oman which was attributed only to cold sea surface temperature (SST) eddies (during November to early December months of 1996-1999), whereas recent study has shown that during dust storms (June-July-August and October-November-December months of 1997-2004), major nutrient supply is from atmospheric dust deposition. We have carried out a study of individual cases of major dust storms over the Arabian Sea during the entire year (December 2003-December 2006) to quantify role of dust storms and changes in ocean surface due to chlorophyll bloom. Using Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua, we have found that the deposition of dust along the passage of major dust storms (aerosol optical depth (AOD) ˜0.25-0.41) occuring over the Arabian Sea causes chlorophyll blooming (usually 10-22.43 mg/m3) within a period of 1-2 to up to 3-4 days. However, we have also found significant anomalous cooling of the ocean surface (SST) and relatively higher ocean wind speeds (QuikSCAT) during dust storms that may lead to favorable conditions for blooming. Exact nature and cause of chlorophyll bloom in the semienclosed northern Arabian Sea, surrounded by one of the world's major sources of dust storms (Africa, Middle East, Iran, and Afghanistan), are very important in understanding the productivity and the biogeochemical cycles of the marine ecosystem. The results have been validated using the Indian Remote Sensing Polar-4 Ocean Color Monitor (IRS P4 OCM) data.

  11. Quantifying the Impact of Icelandic Dust Storms on High-Latitude Aerosol

    Science.gov (United States)

    Browse, Jo; Dorsi, Kelly; Dagsson Waldhauserova, Pavla; Murray, Ben

    2017-04-01

    Using a combination of observations, meteorological climatologies and modelling we have developed an Icelandic dust storm emission inventory. Here we present results from a global modelling study quantifying the contribution of Icelandic dust to high-latitude: ice nucleating particles (INP), cloud condensation nuclei (CCN) and PM2.5. Our results suggest that Icelandic dust cannot explain the formation and persistence of summertime mixed-phase Arctic marine clouds, as summertime marine clouds are too warm for Icelandic dust to serve as INP. However, in colder regions (such as Greenland) Icelandic dust may sporadically contribute to INP. The contribution of Icelandic dust to high-latitude CCN was shown to be complex. Indeed, our results indicate a decrease in high-latitude CCN in the aftermath of Icelandic dust storms. This decrease is due to the short-term increase of the Arctic atmospheric condensation sink and the resulting suppression of nucleation processes (a significant source of Arctic summertime CCN). Finally, Icelandic dust storms are shown to significantly contribute to high-latitude summertime PM2.5 (and PM10) both during (˜100 {μ}gm-3) and in the aftermath (˜10 {μ}gm-3) of dust events. Our results suggest that Icelandic dust storms (neglected in most global climate models) may in the short term increase aerosol optical depth (strongly correlated to PM2.5) at high latitudes. Additionally, Icelandic dust storms are likely to contribute to poor air quality as well as reduced visibility in the Arctic boundary layer. Thus, we argue for the adoption of high-latitude dust emissions in climate and NWP models.

  12. Dust-infused baroclinic cyclone storm clouds: The evidence, meteorology, and some implications

    Science.gov (United States)

    Fromm, Michael; Kablick, George; Caffrey, Peter

    2016-12-01

    Desert mineral dust is a critical yet still poorly understood component of atmospheric composition, weather, and climate. Long-range transport of dust is well known, yet uncertainty persists regarding the pathway from the desert floor to the free troposphere. Here we will show that a recurrent pathway for dust into the uppermost troposphere involves passage through an extratropical baroclinic cyclonic storm. The evidence derives from a synergistic use of satellite-based, multispectral nadir-image data and lidar. The dust-infused baroclinic storm (DIBS) exhibits peculiar cirrus cloud top reflected and emitted radiance from the UV through thermal IR, involving positive UV absorbing aerosol index, muted visible reflectivity, visible cumuliform texture, and systematically intense visible lidar backscatter on a synoptic scale. Proof that the DIBS is microphysically impacted by storm-scale dust infusion is the occurrence of anomalously large daytime 3.9-11μm brightness temperature difference indicative of small ice crystals. We present multispectral snapshots of two DIBS, over two desert source regions, in comparison with a pristine baroclinic storm cloud. Each storm snapshot is presented in the context of the baroclinic cyclone's lifetime and dust source region (the Gobi desert and the Sahara). These and other cases discussed show that the DIBS is a recurring conduit for long-range transport and a natural experiment in dust-related aerosol indirect effects.

  13. Insights into Indoor/Outdoor PM Concentration Ratios due to Dust Storms in an Arid Region

    Directory of Open Access Journals (Sweden)

    Helena Krasnov

    2015-06-01

    Full Text Available Dust storms have impacts on both human and physical environments, associated with an increase in atmospheric particulate matter (PM concentrations. Most studies on exposure to PM have focused on the outdoor air, while information on indoor pollution, is still lacking. The aim of this study was to examine the impact of desert dust events on PM concentrations in indoor environments. A total of over 200 real time measurements of PM were conducted in houses in the Negev Desert during dust storms. Indoor and outdoor PM concentrations were characterized, as well as the relationships between the two datasets. The findings indicated that atmospheric PM10 concentrations can increase from 20–120 μg·m−3 on non-dust days to more than 1500 μg·m−3 during dust events. Indoor concentrations can reach as high as 1000 μg·m−3. The calculated indoor/outdoor (I/O PM ratio ranged from 0.79 for low-level storms to 0.58 during stronger events. Indoor PM concentrations were found to be dependent on the dust storm intensity (low, medium, high and duration with a time lag. The information obtained in this study is critical for assessment of policy interventions to reduce exposure risk and health effects due dust storms.

  14. Characteristics of 14C and 13C of carbonate aerosols in dust storm events in China

    Science.gov (United States)

    Chen, Bing; Jie, Dongmei; Shi, Meinan; Gao, Pan; Shen, Zhenxing; Uchida, Masao; Zhou, Liping; Liu, Kexin; Hu, Ke; Kitagawa, Hiroyuki

    2015-10-01

    In contrast with its decrease in western China deserts, the dust storm event in eastern China, Korea, and Japan shows an increase in frequency. Although the drylands in northeastern China have been recognized as an important dust source, the relative contributions of dust transport from the drylands and deserts are inconclusive, thus the quantification of dust storm sources in downwind area remains a challenge. We measured the 14C and 13C contents in carbonates of dust samples from six sites in China, which were collected for the duration of dust storm events in drylands, deserts, and urban areas. The δ13C of the dryland dust samples considerably varied in a range of - 9.7 to - 5.0‰, which partly overlapped the desert dust carbonate δ13C ranges. The 14C content of the dryland dust carbonates showed a narrow range of 60.9 ± 4.0 (as an average and 1 SD of five samples) percent modern carbon (pMC), indicating the enrichment of modern carbonate. Dust samples in desert regions contained relatively aged carbonates with the depleting 14C showing of 28.8 ± 3.3 pMC. After the long-range transport of the western China desert dust plume, the carbonates collected at the southern China remained the depletion of 14C (33.5 ± 5.3 pMC) as in the desert regions. On the other hand, the samples of dust storm events at the urban areas of eastern China showed an enrichment of 14C contents (46.2 ± 5.0 pMC, n = 7), which might be explained by the stronger contribution of modern-carbonate-rich dryland dust.

  15. Characterization of dustfall in rural and urban sites during three dust storms in northern China, 2010

    Science.gov (United States)

    Lyu, Yanli; Qu, Zhiqiang; Liu, Lianyou; Guo, Lanlan; Yang, Yanyan; Hu, Xia; Xiong, Yiying; Zhang, Guoming; Zhao, Mengdi; Liang, Bo; Dai, Jiadong; Zuo, Xiyang; Jia, Qingpan; Zheng, Hao; Han, Xujiao; Zhao, Shoudong; Liu, Qi

    2017-10-01

    Dust transport and deposition processes are important for understanding the environmental risk of dust storms. This study investigated characteristics of dustfall at two rural sites and four urban sites from dust sources to downwind regions during three dust storms (DS1: March 19-22, DS2: April 24-26, DS3: May 7-10, 2010). Analysis of near-surface instantaneous maximum wind speed and prevailing wind direction revealed the dust storms bursted out from northwestern arid and semiarid regions to eastern China. Microaggregates, angular, subangular, columnar, subrounded, and spherical particles were identified by scanning electron microscope. Dust deposition flux (DDF) during the dust storms was significantly high at sites near sand deserts and sandy land. During DS2, DDF was 25.1, 9.9, 2.3, and 1.5 g m-2 in Jingbian, Shapotou, Lanzhou, and Beijing, respectively. The three dust storms contributed 7.3% of Beijing's annual dustfall in 2010, which suggests anthropogenic dust might contribute the majority of annual dustfall in urban areas. The mass medium diameter of dustfall during DS2 in Shapotou, Jingbian, Lanzhou, and Beijing was 26.1, 9.0, 16.4, and 15.5 μm, respectively. Urban dustfall contained more heavy metals, sulfur and arsenic than rural dustfall. Cadmium contamination was identified in all urban dust particles. Anthropogenic pollutants in combination with mineral dust might lead to complex environmental risk on local, regional, and global scales. China's environmental pollution control should integrate reductions in land desertification and multisource anthropogenic emissions within the context of climate change mitigation.

  16. Contribution of dust storms to PM10 levels in an urban arid environment.

    Science.gov (United States)

    Krasnov, Helena; Katra, Itzhak; Koutrakis, Petros; Friger, Michael D

    2014-01-01

    Quantitative information on the contribution of dust storms to atmospheric PM10 (particulate matter with an aerodynamic diameter storms to PM10 concentrations in a desert urban center, the city of Beer-Sheva, Negev, Israel, during the period of 2001-2012. Toward this end, a background value based on the "dust-free" season was used as a threshold value to identify potentially "dust days." Subsequently, the net contribution of dust storms to PM10 was assessed. During the study period, daily PM10 concentrations ranged from 6 to over 2000 microg/m3. In each year, over 10% of the daily concentrations exceeded the calculated threshold (BVt) of 71 microg/m3. An average daily net contribution of dust to PM10 of 122 microg/m3 was calculated for the entire study period based on this background value. Furthermore, a dust storm intensity parameter (Ai) was used to analyze several storms with very high PM10 contributions (hourly averages of 1000-5197 microg/m3). This analysis revealed that the strongest storms occurred mainly in the last 3 yr of the study. Finally, these findings indicate that this arid urban environment experiences high PM10 levels whose origin lies in both local and regional dust events. The findings indicate that over time, the urban arid environment experiences high PM10 levels whose origin lies in local and regional dust events. It was noticed that the strongest storms have occurred mainly in the last 3 yr. It is believed that environmental changes such as global warming and desertification may lead to an increased air pollution and risk exposure to human health.

  17. Dust storms over the Arabian Gulf: a possible indicator of climate changes consequences

    NARCIS (Netherlands)

    Hamza, W.; Enan, M.R.; Al-Hassini, H.; Stuut, J.B.; de-Beer, D.

    2011-01-01

    Dust storm frequencies and strengths were monitored during 2009 at various locations along the coast of the United Arab Emirates (UAE), as representative sites of the Arabian Gulf marine environment. The results have been compared with a pre-2009 five-year data set. Mineralogical components of dust

  18. Asian dust storm particles induce a broad toxicological transcriptional program in human epidermal keratinocytes.

    Science.gov (United States)

    Choi, Hyun; Shin, Dong Wook; Kim, Wonnyon; Doh, Seong-Jae; Lee, Soo Hwan; Noh, Minsoo

    2011-01-15

    Exposure to airborne dust particles originated from seasonal Asian dust storms in Chinese and Mongolian deserts results in increased incidence of a range of diseases including asthma, contact dermatitis and conjunctivitis. The areas affected by Asian dust particles extend from East China to the west coast of North America. In order to study toxicological mechanisms in human skin, we evaluated the effects of dust particles collected during Asian dust storms (Asian dust particles) on gene expression in human epidermal keratinocytes (HEK). In HEK, exposure to Asian dust particles significantly increased gene expressions of cytochrome P450 1A1 (CYP1A1), CYP1A2, and CYP1B1, which is an indication of aryl hydrocarbon receptor (AHR) activation. In addition, Asian dust particles increased gene transcription of the cytokines IL-6, IL-8, and GM-CSF, which have broad pro-inflammatory and immunomodulatory properties. Asian dust particles significantly up-regulated expression of caspase 14 in HEK, suggesting that Asian dust particles directly affect keratinocyte differentiation. We also demonstrated that protein extract of pollen, a material frequently adsorbed onto Asian dust particles, potentially contributes to the increased transcription of IL-6, CYP1A1, CYP1A2, and CYP1B1. Taken together, these studies suggest that Asian dust particles can exert toxicological effects on human skin through the activation of the cellular detoxification system, the production of pro-inflammatory and immunomodulatory cytokines, and changes in the expression of proteins essential in normal epidermal differentiation.

  19. Typical severe dust storms in northern China during 1954-2002

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zijiang; ZHANG Guocai

    2003-01-01

    Based on China's available daily observation data from 681 national meteorological stations from 1954 to 2002, a time series of typical severe dust storms in northern China is constructed in terms of the weather process, and the temporal and spatial distribution, and their evolution tendency is analyzed. The results indicate that there were 223 relatively typical severe dust storms in northern China from 1954 to 2002, among which the event on April 10-12, 1979 had the largest affected area. Closely associated with the geographical distributionof deserts, sandy lands and the tracks of strong cold air outbreaks, severe dust storms mainly occurred in the Tarim Basin, the eastern part of Northwest Chinaand the northern part of North China. The season with the most frequent severe dust storms was spring, in which the frequency accounts for 82.5% in the whole year, while the least occurrence was in summer and autumn. During the past 49 years, the highest frequency of severe dust storms occurred in the 1950s and the lowest was in the 1990s with a general descending tendency, but during 2000-2002 the occurrence was relatively increasing. On the average, the duration of severedust storms was shortest in the 1990s, about 0.5-1 h shorter than that in the other 4 decades.

  20. Effect of Dust Storms on the Atmospheric Microbiome in the Eastern Mediterranean.

    Science.gov (United States)

    Mazar, Yinon; Cytryn, Eddie; Erel, Yigal; Rudich, Yinon

    2016-04-19

    We evaluated the impact of Saharan dust storms on the local airborne microbiome in a city in the Eastern Mediterranean area. Samples of particles with diameter less than 10 μm were collected during two spring seasons on both dusty and nondusty days. DNA was extracted, and partial 16S rRNA gene amplicons were sequenced using the Illumina platform. Bioinformatic analysis showed the effect of dust events on the diversity of the atmospheric microbiome. The relative abundance of desert soil-associated bacteria increased during dust events, while the relative abundance of anthropogenic-influenced taxa decreased. Quantitative polymerase chain reaction measurements of selected clinically significant antibiotic resistance genes (ARGs) showed that their relative abundance decreased during dust events. The ARG profiles on dust-free days were similar to those in aerosol collected in a poultry house, suggesting a strong agricultural influence on the local ambient profiles. We conclude that dust storms enrich the ambient airborne microbiome with new soil-derived bacteria that disappear as the dust settles, suggesting that the bacteria are transported attached to the dust particles. Dust storms do not seem to be an important vector for transport of probed ARGs.

  1. Investigation of dust storms entering Western Iran using remotely sensed data and synoptic analysis.

    Science.gov (United States)

    Boloorani, Ali D; Nabavi, Seyed O; Bahrami, Hosain A; Mirzapour, Fardin; Kavosi, Musa; Abasi, Esmail; Azizi, Rasoul

    2014-01-01

    One of the natural phenomena which have had considerable impacts on various regions of the world, including Iran, is "dust storm". In recent years, this phenomenon has taken on new dimensions in Iran and has changed from a local problem to a national issue. This study is an attempt to investigate the formation of the dust storms crossing the Western Iran. To find the sources of the dust storms entering Iran, first we examine three determined dust paths in the region and their temporal activities, using MODIS satellite images. Then, four regions were identified as dust sources through soil, land cover and wind data. Finally, atmospheric analyses are implemented to find synoptic patterns inducing dust storms. Source 1 has covered the region between the eastern banks of Euphrates and western banks of Tigris. Source 2 is in desert area of western and south-western Iraq. Finally source 3 is bounded in eastern and south-eastern deserts of Saudi Arabia called Rub-Al-Khali desert, or Empty Quarter. Moreover, south-eastern part of Iraq (source 4) was also determined as a secondary source which thickens the dust masses originating from the above mentioned sources. The study of synoptic circulations suggests that the dust storms originating from source 1 are formed due to the intense pressure gradient between the low-pressure system of Zagros and a high-pressure cell formed on Mediterranean Sea. The dust events in sources 2 and 3 are outcomes of the atmospheric circulations dominant in the cold period of the year in mid-latitudes.

  2. From Source to City: Particulate Matter Concentration and Size Distribution Data from an Icelandic Dust Storm

    Science.gov (United States)

    Thorsteinsson, T.; Mockford, T.; Bullard, J. E.

    2015-12-01

    Dust storms are the source of particulate matter in 20%-25% of the cases in which the PM10health limit is exceeded in Reykjavik; which occurred approximately 20 times a year in 2005-2010. Some of the most active source areas for dust storms in Iceland, contributing to the particulate matter load in Reykjavik, are on the south coast of Iceland, with more than 20 dust storm days per year (in 2002-2011). Measurements of particle matter concentration and size distribution were recorded at Markarfljot in May and June 2015. Markarfljot is a glacial river that is fed by Eyjafjallajokull and Myrdalsjokull, and the downstream sandur areas have been shown to be significant dust sources. Particulate matter concentration during dust storms was recorded on the sandur area using a TSI DustTrak DRX Aerosol Monitor 8533 and particle size data was recorded using a TSI Optical Particle Sizer 3330 (OPS). Wind speed was measured using cup anemometers at five heights. Particle size measured at the source area shows an extremely fine dust creation, PM1 concentration reaching over 5000 μg/m3 and accounting for most of the mass. This is potentially due to sand particles chipping during saltation instead of breaking uniformly. Dust events occurring during easterly winds were captured by two permanent PM10 aerosol monitoring stations in Reykjavik (140 km west of Markarfljot) suggesting the regional nature of these events. OPS measurements from Reykjavik also provide an interesting comparison of particle size distribution from source to city. Dust storms contribute to the particular matter pollution in Reykjavik and their small particle size, at least from this source area, might be a serious health concern.

  3. Forecasting severe ice storms using numerical weather prediction: the March 2010 Newfoundland event

    OpenAIRE

    Hosek, J.; P. Musilek; E. Lozowski; Pytlak, P.

    2011-01-01

    The northeast coast of North America is frequently hit by severe ice storms. These freezing rain events can produce large ice accretions that damage structures, frequently power transmission and distribution infrastructure. For this reason, it is highly desirable to model and forecast such icing events, so that the consequent damages can be prevented or mitigated. The case study presented in this paper focuses on the March 2010 ice storm event that took place in eastern Newfoundland. We apply...

  4. A Case Study of a Typical Dust Storm Event over the Loess Plateau of Northwest China

    Institute of Scientific and Technical Information of China (English)

    LING Xiao-Lu; GUO Wei-Dong; ZHAO Qian-Fei; ZHANG Bei-Dou

    2011-01-01

    Enhanced observational meteorological elements, energy fluxes, and the concentration of dust aerosols collected from the Semi-Arid Climate Observatory and Laboratory (SACOL) during a typical dust storm period in March 2010 at Lanzhou were used in this paper to investigate the impact of dust aerosols on near surface atmospheric variables and energy budgets. The results show that the entire dust storm event was associated with high wind velocities and decreasing air pressure, and the air changed from cold and wet to warm and dry and then recovered to its initial state. The response of energy fluxes occurred behind meteorological elements. At high dust concentration periods, the net radiation was significantly less in the daytime and higher at night, while the heat fluxes displayed the same trend, indicating the weakening of the land-atmosphere energy exchange. The results can be used to provide verification for numerical model results in semi-arid areas.

  5. Implementation of dust emission and chemistry into the Community Multiscale Air Quality modeling system and initial application to an Asian dust storm episode

    Directory of Open Access Journals (Sweden)

    K. Wang

    2012-11-01

    Full Text Available The US Environmental Protection Agency's (EPA Community Multiscale Air Quality (CMAQ modeling system version 4.7 is further developed to enhance its capability in simulating the photochemical cycles in the presence of dust particles. The new model treatments implemented in CMAQ v4.7 in this work include two online dust emission schemes (i.e., the Zender and Westphal schemes, nine dust-related heterogeneous reactions, an updated aerosol inorganic thermodynamic module ISORROPIA II with an explicit treatment of crustal species, and the interface between ISORROPIA II and the new dust treatments. The resulting improved CMAQ (referred to as CMAQ-Dust, offline-coupled with the Weather Research and Forecast model (WRF, is applied to the April 2001 dust storm episode over the trans-Pacific domain to examine the impact of new model treatments and understand associated uncertainties. WRF/CMAQ-Dust produces reasonable spatial distribution of dust emissions and captures the dust outbreak events, with the total dust emissions of ~111 and 223 Tg when using the Zender scheme with an erodible fraction of 0.5 and 1.0, respectively. The model system can reproduce well observed meteorological and chemical concentrations, with significant improvements for suspended particulate matter (PM, PM with aerodynamic diameter of 10 μm, and aerosol optical depth than the default CMAQ v4.7. The sensitivity studies show that the inclusion of crustal species reduces the concentration of PM with aerodynamic diameter of 2.5 μm (PM2.5 over polluted areas. The heterogeneous chemistry occurring on dust particles acts as a sink for some species (e.g., as a lower limit estimate, reducing O3 by up to 3.8 ppb (~9% and SO2 by up to 0.3 ppb (~27% and as a source for some others (e.g., increasing fine-mode SO42− by up to 1.1 μg m−3 (~12% and PM2.5 by up to 1.4 μg m−3 (~3% over the domain. The

  6. A Look at Dust Storms on Mars (2007 To 2009) Using MCS and THEMIS Observations

    Science.gov (United States)

    Flynn, William; Bowles, N. E.; Teanby, N. A.; Montabone, L.; Calcutt, S. B.; Read, P. L.; Kass, D. M.; Hale, A. S.

    2009-09-01

    Martian dust storms may be small, localised and short lived or can be large and intense and expand to enshroud most, if not all, of the planet within a few days. The martian dusty season occurs near the time of perihelion (closest approach to the sun) during Mars' southern hemisphere spring and summer. During this period (+/- 90 degrees Ls of perihelion) local and regional dust storms are more frequent and there is a higher probability of a major and possible planet-encircling dust storm occuring. Despite this there is still a lot of interannual variability and uncertainty regarding the occurence of both major and regional dust storms. The Mars Climate Sounder (MCS) instrument onboard NASA's Mars Reconnaissance Orbiter (MRO) is a two telescope 9 channel filter IR radiometer (0.3 to 45 microns), with each channel consisting of a linear array of 21 detectors. Each pixel sounds a 5km thick region of the Martian atmosphere in a limb viewing/scanning mode. We present a comparison of dust storm activity on Mars for 2007 to 2009 using MCS limb observations of changes in dust opacity. These measurements are also compared with observations and atmospheric opacity maps generated by the Thermal Emission Imaging System (THEMIS) multi-wavelength instrument onboard the Mars Odyssey spacecraft and Mars weather maps from MRO's Mars Color Imager (MARCI) for this period. Model predictions from the Mars Climate Database and simulations from the UK Mars General Circulation Model (GCM) are also used. This comparison gives us an empirical method for using MCS data directly to identify dust storm activity during this period.

  7. Dust storm detection using random forests and physical-based approaches over the Middle East

    Indian Academy of Sciences (India)

    Amir Hossein Souri; Sanaz Vajedian

    2015-07-01

    Dust storms are important phenomena over large regions of the arid and semi-arid areas of the Middle East. Due to the influences of dust aerosols on climate and human daily activities, dust detection plays a crucial role in environmental and climatic studies. Detection of dust storms is critical to accurately understand dust, their properties and distribution. Currently, remotely sensed data such as MODIS (Moderate Resolution Imaging Spectroradiometer) with appropriate temporal and spectral resolutions have been widely used for this purpose. This paper investigates the capability of two physical-based methods, and random forests (RF) classifier, for the first time, to detect dust storms using MODIS imagery. Since the physical-based approaches are empirical, they suffer from certain drawbacks such as high variability of thresholds depending on the underlying surface. Therefore, classification-based approaches could be deployed as an alternative. In this paper, the most relevant bands are chosen based on the physical effects of the major classes, particularly dust, cloud and snow, on both emissive infrared and reflective bands. In order to verify the capability of the methods, OMAERUV AAOD (aerosol absorption optical depth) product from OMI (Ozone Monitoring Instrument) sensor is exploited. In addition, some small regions are selected manually to be considered as ground truth for measuring the probability of false detection (POFD) and probability of missing detection (POMD). The dust class generated by RF is consistent qualitatively with the location and extent of dust observed in OMERAUV and MODIS true colour images. Quantitatively, the dust classes generated for eight dust outbreaks in the Middle East are found to be accurate from 7% and 6% of POFD and POMD respectively. Moreover, results demonstrate the sound capability of RF in classifying dust plumes over both water and land simultaneously. The performance of the physical-based approaches is found weaker than RF

  8. Accelerating Dust Storm Simulation by Balancing Task Allocation in Parallel Computing Environment

    Science.gov (United States)

    Gui, Z.; Yang, C.; XIA, J.; Huang, Q.; YU, M.

    2013-12-01

    Dust storm has serious negative impacts on environment, human health, and assets. The continuing global climate change has increased the frequency and intensity of dust storm in the past decades. To better understand and predict the distribution, intensity and structure of dust storm, a series of dust storm models have been developed, such as Dust Regional Atmospheric Model (DREAM), the NMM meteorological module (NMM-dust) and Chinese Unified Atmospheric Chemistry Environment for Dust (CUACE/Dust). The developments and applications of these models have contributed significantly to both scientific research and our daily life. However, dust storm simulation is a data and computing intensive process. Normally, a simulation for a single dust storm event may take several days or hours to run. It seriously impacts the timeliness of prediction and potential applications. To speed up the process, high performance computing is widely adopted. By partitioning a large study area into small subdomains according to their geographic location and executing them on different computing nodes in a parallel fashion, the computing performance can be significantly improved. Since spatiotemporal correlations exist in the geophysical process of dust storm simulation, each subdomain allocated to a node need to communicate with other geographically adjacent subdomains to exchange data. Inappropriate allocations may introduce imbalance task loads and unnecessary communications among computing nodes. Therefore, task allocation method is the key factor, which may impact the feasibility of the paralleling. The allocation algorithm needs to carefully leverage the computing cost and communication cost for each computing node to minimize total execution time and reduce overall communication cost for the entire system. This presentation introduces two algorithms for such allocation and compares them with evenly distributed allocation method. Specifically, 1) In order to get optimized solutions, a

  9. Evaluation and Correction of Quantitative Precipitation Forecast by Storm-Scale NWP Model in Jiangsu, China

    Directory of Open Access Journals (Sweden)

    Gaili Wang

    2016-01-01

    Full Text Available With the development of high-performance computer systems and data assimilation techniques, storm-scale numerical weather prediction (NWP models are gradually used for short-term deterministic forecasts. The primary objective of this study is to evaluate and correct precipitation forecasts of a storm-scale NWP model called the advanced regional prediction system (ARPS. The evaluation and correction consider five heavy precipitation events that occurred in the summer of 2015 in Jiangsu, China. The performances of the original and corrected ARPS precipitation forecasts are evaluated as a function of lead time using standard measurements and a spatial verification method called Structure-Amplitude-Location (SAL. In general, the ARPS could not produce optimal forecasts for very short lead times, and the forecast accuracy improves with increasing lead time. The ARPS overestimates precipitation for all lead times, which is confirmed by large bias in many forecasts in the first and second quadrant of the diagram of SAL, especially at the 1 h lead time. The amplitude correction is performed by matching percentile values of the ARPS precipitation forecasts and observations for each lead time. Amplitude correction significantly improved the ARPS precipitation forecasts in terms of the considered performance indices of standard measures and A-component and S-component of SAL.

  10. A High-resolution Dust Aerosol Model For Numerical Study of Asian Dust Storms in April 2001

    Science.gov (United States)

    Liu, M.; Westphal, D. L.; Wang, S.; Sugimoto, N.; Shimizu, A.; Zhou, J.; Chen, Y.

    2002-12-01

    A comprehensive dust aerosol model is developed and fully coupled to the US Navy's operational Coupled Ocean/Atmospheric Mesoscale Prediction System (COAMPSTM). The model is used to simulate the Asian dust storms of April 5th to 15th, 2001, at 27-km resolution with 10 particle bins. Dust is mainly generated from the Gobi and Takalamakan Deserts between the 6th and 9th and the dust plumes sweep over the vast areas of East Asia. The model performance is well verified by the observations at Lanzhou for surface PM10 concentrations, and at Beijing, Hefei, Tsukuba, and Nagasaki for vertical Lidar depolarization and extinction coefficients. The model simulates the right timing of dust events and predicts the boundary layer and elevated layer of dust plumes passing through these cities as observed. The numerical analyses show that the first Mongolia cyclone on the 6th and 7th and the cold front on the 8th and 9th (accompanied with a second Mongolia low) are the major dynamic forcing which mobilize, vertically redistribute and transport the dust. Both the cyclones entrain the dust into their inner cyclonic flow structures, reaching 6-8 km altitudes, while on the outer edges of cyclones, transport is anti-cyclonic and to the northeast. The prognostics of individual dynamic and microphysical processes in the model continuity equation reveal that the vertical advection by the resolved upward motion within the cyclones is a dominant component to the mass tendency. The mass budget calculations for the whole simulation period display the most portion of the dust production from Asian deserts falling onto the land by dry deposition and wet removal, indicating severe environment problems caused by dust storms.

  11. Statistical guidance on seasonal forecast of Korean dust days over South Korea in the springtime

    Science.gov (United States)

    Sohn, Keon Tae

    2013-09-01

    This study aimed to develop the seasonal forecast models of Korean dust days over South Korea in the springtime. Forecast mode was a ternary forecast (below normal, normal, above normal) which was classified based on the mean and the standard deviation of Korean dust days for a period of 30 years (1981-2010). In this study, we used three kinds of monthly data: the Korean dust days observed in South Korea, the National Center for Environmental Prediction in National Center for Atmospheric Research (NCEP/NCAR) reanalysis data for meteorological factors over source regions of Asian dust, and the large-scale climate indices offered from the Climate Diagnostic Center and Climate Prediction Center in NOAA. Forecast guidance consisted of two components; ordinal logistic regression model to generate trinomial distributions, and conversion algorithm to generate ternary forecast by two thresholds. Forecast guidance was proposed for each month separately and its predictability was evaluated based on skill scores.

  12. The relationship between gorgonian coral (Cnidaria: Gorgonacea) diseases and African dust storms

    Science.gov (United States)

    Weir-Brush, J. R.; Garrison, V.H.; Smith, G.W.; Shinn, E.A.

    2004-01-01

    The number of reports of coral diseases has increased throughout the world in the last 20 years. Aspergillosis, which primarily affects Gorgonia ventalina and G. flabellum, is one of the few diseases to be characterized. This disease is caused by Aspergillus sydowii, a terrestrial fungus with a worldwide distribution. Upon infection, colonies may lose tissue, and ultimately, mortality may occur if the infection is not sequestered. The spores of A. sydowii are <5 ??m, small enough to be easily picked up by winds and dispersed over great distances. Aspergillosis is prevalent in the Caribbean, and it appears that this primarily terrestrial fungus has adapted to a marine environment. It has been proposed that dust storms originating in Africa may be one way in which potential coral pathogens are distributed and deposited into the marine environments of the Caribbean. To test the hypothesis that African dust storms transport and deposit pathogens, we collected air samples from both dust storms and periods of nondust in St. John, U.S. Virgin Islands. Because we focused on fungal pathogens and used A. sydowii as a model, we isolated and cultured fungi on various types of media. Fungi including Aspergillus spp. were isolated from air samples taken from dust events and non-dust events. Twenty-three separate cultures and seven genera were isolated from dust event samples whereas eight cultures from five genera were isolated from non-dust air samples. Three isolates from the Virgin Islands dust event samples morphologically identified as Aspergillus spp. produced signs of aspergillosis in seafans, and the original pathogens were re-isolated from those diseased seafans fulfilling Koch's Postulates. This research supports the hypothesis that African dust storms transport across the Atlantic Ocean and deposit potential coral pathogens in the Caribbean.

  13. Unraveling Local Dust Storm Structure on Mars: The Case of Northern Amazonis During Mars Year 24

    Science.gov (United States)

    Heavens, N. G.

    2015-12-01

    On an average Martian afternoon, two or three local dust storms are taking place somewhere on the planet. By definition, these storms range in area from a few square kilometers to hundreds of thousands, rarely surviving from sol to the next. After more than 40 years of observation, a great deal is known about where and when they occur, but very little is known about the structure and dynamics of individual storms. This contrast in our knowledge about local dust storms results from how they are observed. Daily global mapping of Mars in the visible has enabled an accurate census of storms as well as observation of their morphological diversity. However, even under ideal conditions, an individual storm is only observed by sounder-type instrumentation once or twice (if it is a large enough), providing an incomplete picture of structure of an individual storm. Early studies of cyclogenesis on Earth had a similar problem. Cyclones were many, but observations of individual cyclones, especially over the ocean, were sparse. The structure and dynamics of cyclones was unraveled by noting similarities in properties between certain classes of cyclones and using observational data to generate composite cyclones that could be analyzed and modeled. Variability within the composite also could be studied. Here I establish the existence of a well-defined class of Martian local dust storms defined by: (1) occurrence along the axis of the dark albedo feature in northern Amazonis Planitia (36 N, 155 W); (2) not being associated with lifting or cloudiness due to a baroclinic wave/frontal boundary at higher latitude; (3) being textured, that is, having dust clouds with sharp, well-defined features that are thought to indicate their clouds are supplied by the active lifting of dust; (4) having dust clouds organized in well-defined streets indicative of convective rolls. In Mars Year 24, such storms developed on thirteen occasions in northern fall and autumn. Using data from the Mars

  14. Investigation of Three-Dimensional Evolution of East Asian Dust Storm by Modeling and Remote Sensing Measurements

    Directory of Open Access Journals (Sweden)

    Jiawei Li

    2015-01-01

    Full Text Available The three-dimensional evolution of an East Asian dust storm during 23–26 April 2009 was investigated by utilizing a regional air quality model system (RAQMS and satellite measurements. This severe dust storm hit Mt. Tai in east China with daily mean PM10 concentration reaching 1400 μg/m3 and the model captured the PM10 variation reasonably well. Modeled spatial distributions of AOD and vertical profiles of aerosol extinction coefficient during the dust storm were compared with MODIS and CALIPSO data, demonstrating that RAQMS was able to reproduce the 3D structure and the evolution of the dust storm reasonably well. During early days of the dust storm, daily mean dust-induced AOD exceeded 2.0 over dust source regions (the Gobi desert and the Taklamakan desert and was in a range of 1.2–1.8 over the North China Plain, accounting for about 98% and up to 90% of total AOD over corresponding areas, respectively. The top of the dust storm reached about 8 km over east China, with high dust concentration locating at around 40°N. Dust aerosol below 2 km was transported southeastward off the Gobi desert while dust above 2 km was transported out of China along 40°–45°N.

  15. Improving short-range ensemble Kalman storm surge forecasting using robust adaptive inflation

    NARCIS (Netherlands)

    Altaf, M.U.; Butler, T.; Luo, X.; Dawson, C.; Mayo, T.; Hoteit, I.

    2013-01-01

    This paper presents a robust ensemble filtering methodology for storm surge forecasting based on the singular evolutive interpolated Kalman (SEIK) filter, which has been implemented in the framework of the H∞ filter. By design, an H∞ filter is more robust than the common Kalman filter in the sense t

  16. Improving short-range ensemble Kalman storm surge forecasting using robust adaptive inflation

    NARCIS (Netherlands)

    Altaf, M.U.; Butler, T.; Luo, X.; Dawson, C.; Mayo, T.; Hoteit, I.

    2013-01-01

    This paper presents a robust ensemble filtering methodology for storm surge forecasting based on the singular evolutive interpolated Kalman (SEIK) filter, which has been implemented in the framework of the H∞ filter. By design, an H∞ filter is more robust than the common Kalman filter in the sense t

  17. Influence of Asian dust storms on daily acute myocardial infarction hospital admissions.

    Science.gov (United States)

    Teng, Joshua Chen-Yuan; Chan, Yun-Shan; Peng, Yu-I; Liu, Tsai-Ching

    2016-01-01

    This study was the first to explore the relationship between Asian dust storm events (ADS) and acute myocardial infarction (AMI) hospital admissions by applying time series models. Nationwide population-based hospitalization claims data in Taiwan were used. There were 143,063 AMI admissions during 2000-2009. An autoregressive with exogenous variables (ARX) time series model was used to investigate the dynamic connection between AMI hospital admissions and ADS events. AMI hospitalizations significantly spiked on post-ADS day three. Among the total population, 3.2 more cases of AMI admissions occurred on post-ADS day three. When the data were stratified by age and gender, the same delayed effect was present in the male population, especially those aged 45-64 and over 74. Our study shows that although an ADS event does not cause an immediate incidence of AMI, storms may increase AMI incidence through a delayed effect. Hence, AMI prevention is not only important during a dust storm, but particularly so in subsequent days. During the days after an ADS, exposure to dust should be minimized by staying indoors as much as possible and by wearing a mask when exposure to dust is unavoidable. This is especially true for working and older adults. Nurses at local public health centers can increase awareness and promote public safety by providing health information to local communities regarding the link between dust storms and AMI. © 2015 Wiley Periodicals, Inc.

  18. High Proportions of Sub-micron Particulate Matter in Icelandic Dust Storms in 2015

    Science.gov (United States)

    Dagsson Waldhauserova, Pavla; Arnalds, Olafur; Olafsson, Haraldur; Magnusdottir, Agnes

    2017-04-01

    Iceland is extremely active dust region and desert areas of over 44,000 km2 acknowledge Iceland as the largest Arctic and European desert. Frequent dust events, up to 135 dust days annually, transport dust particles far distances towards the Arctic and Europe. Satellite MODIS pictures have revealed dust plumes exceeding 1,000 km. The annual dust deposition was calculated as 40.1 million tons yr-1. Two dust storms were measured in transverse horizontal profile about 90 km far from different dust sources in southwestern Iceland in the summer of 2015. Aerosol monitor DustTrak DRX 8533EP was used to measure PM mass concentrations corresponding to PM1, PM2.5, PM4, PM10 and the total PM15 at several places within the dust plume. Images from camera network operated by the Icelandic Road and Coastal Administration were used to estimate the visibility and spatial extent of measured dust events. A numerical simulation of surface winds was carried out with the numerical model HIRLAM with horizontal resolution of 5 km and used to calculate the total dust flux from the sources. The in situ measurements inside the dust plumes showed that aeolian dust can be very fine. The study highlights that suspended volcanic dust in Iceland causes air pollution with extremely high PM1 concentrations comparable to the polluted urban stations in Europe or Asia rather than reported dust event observations from around the world. The PM1/PM2.5 ratios are generally low during dust storms outside of Iceland, much lower than > 0.9 and PM1/PM10 ratios of 0.34-0.63 found in our study. It shows that Icelandic volcanic dust consists of higher proportion of submicron particles compared to crustal dust. The submicron particles are predicted to travel long distances. Moreover, such submicron particles pose considerable health risk because of high potential for entering the lungs. Icelandic volcanic glass has often fine pipe-vesicular structures known from asbestos and high content of heavy metals. Previous

  19. NM-MT network and space dangerous phenomena, 1. Principles of major geomagnetic storms forecasting

    Science.gov (United States)

    Dorman, L.; Pustil Nik, L.; Sternlieb, A.; Zukerman, I.

    According to NOAA Space Weather Scales, geomagnetic storms of scales G5 (3- hour index of geomagnetic activity Kp=9), G4 (Kp=8) and G3 (Kp=7) are dangerous for people technology and health (influence on power systems, on spacecraft operations, on HF radio-communications and others). To prevent these serious damages will be very important to forecast dangerous geomagnetic storms. In many papers it was shown that in principle for this forecasting can be used data on CR intensity and CR anisotropy changing before SC of major geomagnetic storms accompanied by sufficient Forbush-decreases (e.g., Dorman et al., 1995, 1999). In this paper we consider over 100 major geomagnetic storms and for each case we analyze hourly data of many NM for 8 days with SC in the 4-st day of 8 days period (so before SC we have at least 3 full days). We- determine what part of major geomagnetic storms is accompanied CR intensity and CR anisotropy changing before SC, and what part of major geomagnetic storms does not show any features what can be used for forecasting. We estimate also how these parts depend from the index of geomagnetic activity Kp. This research is partly supported by the INTAS grant 00-0810. REFERENCES: Dorman L.I., et al. "Cosmic-ray forecasting features for big Forbush-decreases". Nuclear Physics B, 49A, 136-144 (1995). L.I.Dorman, et al, "Cosmic ray Forbush-decrease as indicators of space dangerous phenomenon and possible use of cosmic ray data for their prediction", Proc. of 26-th Intern. Cosmic Ray Conference, Salt Lake City, 6, 476-479 (1999).

  20. Dust storms come to central and southwestern China, too: implications from a major dust event in Chongqing

    Directory of Open Access Journals (Sweden)

    Q. Zhao

    2009-12-01

    Full Text Available Dust storms from major Asian sources are usually carried by northwesterly or westerly winds over northern and southeastern China to the Pacific Ocean. These pathways leave central and southwestern China nearly free of incursions. But a strong dust event on 5–6 May 2005 was captured in a 15-month series of weekly filter samples of PM2.5 at three sites in Chongqing. It illustrated that desert dust can be transported to this region, and sometimes strongly. Annual PM2.5 and dust were similar at the three sites, but higher than in simultaneous samples in Beijing. High correlations of dust concentration were found between the cites during spring, indicating that Asian dust affects a broader swath of China than is often realized. During the event, the concentrations of mineral dust were high at all sites (20–30 μg m−3; 15%–20% of PM2.5 in Chongqing, and 15 μg m−3; 20%–30% of PM2.5 in Beijing, and were part of a broader spring maximum. The proportions of crustal elements and pollution-derived components such as Pb, SO42−, and organic carbon indicated that the sources for this dust differed from Beijing. The dust was considerably enriched in Ca and Mg, characteristic of western deserts, whereas Beijing's dust had the lower Ca and Mg of eastern deserts. This observation agrees with synoptic patterns and back-trajectories. Driven by a cold air outbreak from the northwest, dust from the western Gobi Desert was transported at lower altitudes (<2 km above ground level, while dust from the Takla Makan Desert was transported to Chongqing at higher altitudes. Desert dust can also be important to wide areas of China during the cold season, since almost all the weekly dust peaks in the two cities coincided with extensive dust emissions in source regions. These findings collectively suggest that the amount of Asian-dust in China has been underestimated both

  1. Analysis on the decadal scale variation of the dust storm in North China

    Institute of Scientific and Technical Information of China (English)

    KANG Dujuan; WANG Huijun

    2005-01-01

    In this paper, the temporal variation characteristics of the dust storm in North China are investigated. Based on power spectrum analysis and wavelet analysis, 1956-1970 and 1985-1999 are chosen as the high-frequency and low-frequency dust storm decades respectively. Analysis results clearly show that the spring and wintertime anomalous atmospheric circulation between these two decades are significantly different. Compared with the former decade, there are a strengthened polar vortex, enhanced westerlies near 50(N, and a weak East Asian major though in the winter of the latter decade. The north and center parts of the Siberian high and the Aleutian low become weak. The southerly and easterly wind anomalies appear over the north and east parts of China, which implies the weakening of East Asian winter monsoon. Meanwhile, northern China experiences warmer winters and wetter springs, which are in favor of the weakening of dust storm intensity in North China. There are significant out-of-phase relationships between dust frequency and wintertime westerly intensity, as well as between dust frequency and Arctic Oscillation. It is also found that the frequency of dust weather is strongly related to winter-springtime East Asian monsoon intensity.

  2. Orbit-Spin Coupling Accelerations and the 2007 Global-Scale Dust Storm on Mars

    Science.gov (United States)

    Shirley, James H.; Mischna, Michael A.

    2016-10-01

    Global-scale dust storms (GDS) occasionally occur during the southern summer season on Mars. The most recent such storm occurred in 2007 (Mars year 28). We employ a modified version of the MarsWRF global circulation model to simulate atmospheric conditions on Mars leading up to this event. Accelerations due to orbit-spin coupling (arxiv.org/abs/1605.02707) have been incorporated within the dynamical core of the MarsWRF GCM (arxiv.org/abs/1602.09137). We have previously documented an "intensification" of the large scale circulation (as represented in the GCM) due to these accelerations during the dust storm season of MY 28. In this presentation we look more closely at the differences between GCM outcomes for runs performed both with and without the "coupling term accelerations" for this important year. The current version of the GCM has a number of shortcomings; most significantly, we do not yet include radiatively active dust within our simulations. The GCM thus cannot replicate the rapid warming and inflation of the atmosphere that occurs soon after significant dust lifting has commenced; and we do not address specific mechanisms of dust lifting. Nonetheless our model outcomes provide some insight into phenomena such as the variability of global wind systems during intervals leading up to the inception of the global storm. The phasing and amplitude of the orbit-spin coupling accelerations (arxiv.org/abs/1605.01452) for the current Mars year (MY 33) are in some ways similar to those calculated for MY 28. Thus we will also examine and describe MarsWRF model outcomes for the current dust storm season.

  3. 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.

  4. Experimental nowcasting and short-range forecasting of severe storms at the ESSL Testbed

    Science.gov (United States)

    Groenemeijer, Pieter; Holzer, Alois M.; Pistotnik, Georg; Riemann-Campe, Kathrin

    2013-04-01

    From 4 June to 6 July 2012, the first ESSL Testbed has taken place at the Research and Training Centre of the European Severe Storms Laboratory in Wiener Neustadt, Austria. During this time, researchers and forecasters worked closely together putting new forecast supporting products to the test. The Testbed's main activity is to prepare experimental forecasts for severe weather, of which short-range forecasts and nowcasts for the following 2 hours form an important part. These nowcasts are made using new tools based on NWP, radar and satellite, as well as surface and upper-air observations. Subsequently, a verification of the forecasts is performed using the European Severe Weather Database, followed by an evaluation of forecasting tools and techniques. Inspired by the annual Spring Program at NOAA's Hazardous Weather Testbed (HWT), the ESSL Testbed has a stronger focus on forecaster training than the HWT. Given the various backgrounds of the participants, an important Testbed goal is to acquaint its participants with severe weather forecasting methods and techniques that work universally. Among the tools that were evaluated at the 2012 Testbed were visualizations of high-resolution ensemble NWP (DWD's COSMO-DE-EPS), satellite-based cloud top cooling and overshooting top detection algorithms, lightning detection, and satellite and radar-based cell-tracking algorithms (DLR's Cb-TRAM and RadTRAM, and DWD's NowcastMix). In daily "Expert Lectures", that were broadcast online to remote participants, researchers provided background information on their products and internationally renowned experts in forecasting presented their viewpoints on storm forecasting and its scientific roots. Organized by ESSL in close cooperation with the Austrian Central Institute for Meteorology and Geodynamics (ZAMG), the Testbed was supported - among others - by the German Weather Service (DWD), EUMETSAT, WMO, ECMWF, VAISALA, and the GOES-R programme, providing products for evaluation and

  5. The Briefing Relating to the Construction of Dust-Storm Monitoring, Predicting and Service System

    Institute of Scientific and Technical Information of China (English)

    ChengLei; WangXuechen

    2005-01-01

    Dust-storm is a kind of severe weather, which has comprehensive and significant impacts on socioeconomic development and people's livelihood. Enhancing the abihties of dust-storm monitoring, predicting and service will be of great benefit and the important significance to China and its people. At present, the comprehensive operation on dust-storm monitoring, predicting and service is still in a preliminary phase, the abilities of operation can' t meet the needs of implementing the real-time and quantitative monitoring and providing the efficient service. The implementation of the project of dust-storm monitoring, predicting and service system will greatly improve the service ability and level for tile sustainable development and make a greater contribution to build the better-off society. The first phase project mainly involves monitoring subsystem, predicting, warning and service subsystem; communications and transmission subsystem, etc. In the first phase construction a series of major measures should be taken to address project overall benefits, such as making better use of current monitoring resource, taking into account the standards of data format and project integrative and extensive abilities and so on.

  6. Dust forecast over North Africa: verification with satellite and ground based observations

    Science.gov (United States)

    Singh, Aditi; Kumar, Sumit; George, John P.

    2016-05-01

    Arid regions of North Africa are considered as one of the major dust source. Present study focuses on the forecast of aerosol optical depth (AOD) of dust over different regions of North Africa. NCMRWF Unified Model (NCUM) produces dust AOD forecasts at different wavelengths with lead time upto 240 hr, based on 00UTC initial conditions. Model forecast of dust AOD at 550 nm up to 72 hr forecast, based on different initial conditions are verified against satellite and ground based observations of total AOD during May-June 2014 with the assumption that except dust, presence of all other aerosols type are negligible. Location specific and geographical distribution of dust AOD forecast is verified against Aerosol Robotic Network (AERONET) station observations of total and coarse mode AOD. Moderate Resolution Imaging Spectroradiometer (MODIS) dark target and deep blue merged level 3 total aerosol optical depth (AOD) at 550 nm and Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) retrieved dust AOD at 532 nm are also used for verification. CALIOP dust AOD was obtained by vertical integration of aerosol extinction coefficient at 532 nm from the aerosol profile level 2 products. It is found that at all the selected AERONET stations, the trend in dust AODs is well predicted by NCUM up to three days advance. Good correlation, with consistently low bias (~ +/-0.06) and RMSE (~ 0.2) values, is found between model forecasts and point measurements of AERONET, except over one location Cinzana (Mali). Model forecast consistently overestimated the dust AOD compared to CALIOP dust AOD, with a bias of 0.25 and RMSE of 0.40.

  7. Territorial Features of Atmospheric Environment in Beijing and Impct of Dust-storm

    Institute of Scientific and Technical Information of China (English)

    RenZhenhai; SuFuqiang; GaoQingxian; WUjianguo; ZhangZhigang; YangXinxing

    2004-01-01

    The territorial features of the amospheric environment in Beijing were described in described in detail,and the transportation pathways of the atmosphere pollutants found by the dot aggregation in the form of the meshwork.The concept on convergence belt of the atmosphere pollutants was given.The vertical distribution of the atmospheric pollutants in Beijing was detected by the neighboring areas of Beijing.The sand-dust storm in China were studie by both satellite inspection technology and analysis of atmospheric flow fields,According tp tje dostrobitopms of sand-dust storm sources to impact on the air environment in China,the sand-dust sources insia were situatad in the desert and Gobi in the Inner Mongolia and Xinjiang autonomous regions .The sand-dust surces outside China were situated in the desert and Gohi in Russina,Hazakhsten and Mongolia.A very strong sand-dust storm taken place on the 20th Mar,2002 is given as exa-mple.

  8. Observation of a Dust Storm during 2015 Spring over Beijing, China

    Science.gov (United States)

    Lv, Y.; Li, D.; Li, Z.; Chen, X.; Xu, H.; Liu, Z.; Qie, L.; Zhang, Y.; Li, K.; Ma, Y.

    2015-12-01

    Dust events bring significant impacts on the regional environment, human health and even climate. There are four major dust explosion areas in the world, such as North America, Australia, Central Asia and Middle East. Located in the Central Asia, North China has a severe desertification because of deforestation and excessive population growth. Beijing is at the fork of three dust transmission paths in Chin, which makes it a dust-prone region for a long history especially in spring. Thanks to the improvement of the ecological environment in Mongolia, the number of dust weather in recent years reduced significantly than before. However, as the spring coming earlier for the relatively high temperature, a severe dust weather process happened suddenly on March 28, 2015 following with the long-term hazy weather, which up to the highest intensity in the nearly two years. A set of ground-based observations for this serious dust event were adopted in this paper. The ground-based remote sensing station is equipped with an automatic CIMEL lidar and an AERONET sun-photometer. Aerosol optical depth (AOD) and aerosol size distribution were measured by sun-photometer. AOD of dust reached 2.0 at 532nm, which was much larger than clear days. And there was an obvious trend that coarse mode increases more significantly and quickly than fine mode when a dust storm occurs. At the same time, data provided by the air quality monitoring and analysis platform of China shown that the PM10 concentration was larger than 1000μg/m3 and PM10 made important contribution to the high AQI. Lidar observation clearly shown the dust spread very tall (higher than 1km) when the dust storm occurrence. After the dust dissipating, the planetary boundary layer roughly from 0 to 3km, aerosol has a very widely vertical distribution. The AOD based on sun-photometer were taken as a constraint, 65 sr were retrieved and analyzed. And the extinction coefficients indicated that the dust had been dissipation near

  9. Developing Subdomain Allocation Algorithms Based on Spatial and Communicational Constraints to Accelerate Dust Storm Simulation.

    Directory of Open Access Journals (Sweden)

    Zhipeng Gui

    Full Text Available Dust storm has serious disastrous impacts on environment, human health, and assets. The developments and applications of dust storm models have contributed significantly to better understand and predict the distribution, intensity and structure of dust storms. However, dust storm simulation is a data and computing intensive process. To improve the computing performance, high performance computing has been widely adopted by dividing the entire study area into multiple subdomains and allocating each subdomain on different computing nodes in a parallel fashion. Inappropriate allocation may introduce imbalanced task loads and unnecessary communications among computing nodes. Therefore, allocation is a key factor that may impact the efficiency of parallel process. An allocation algorithm is expected to consider the computing cost and communication cost for each computing node to minimize total execution time and reduce overall communication cost for the entire simulation. This research introduces three algorithms to optimize the allocation by considering the spatial and communicational constraints: 1 an Integer Linear Programming (ILP based algorithm from combinational optimization perspective; 2 a K-Means and Kernighan-Lin combined heuristic algorithm (K&K integrating geometric and coordinate-free methods by merging local and global partitioning; 3 an automatic seeded region growing based geometric and local partitioning algorithm (ASRG. The performance and effectiveness of the three algorithms are compared based on different factors. Further, we adopt the K&K algorithm as the demonstrated algorithm for the experiment of dust model simulation with the non-hydrostatic mesoscale model (NMM-dust and compared the performance with the MPI default sequential allocation. The results demonstrate that K&K method significantly improves the simulation performance with better subdomain allocation. This method can also be adopted for other relevant atmospheric

  10. Developing Subdomain Allocation Algorithms Based on Spatial and Communicational Constraints to Accelerate Dust Storm Simulation.

    Science.gov (United States)

    Gui, Zhipeng; Yu, Manzhu; Yang, Chaowei; Jiang, Yunfeng; Chen, Songqing; Xia, Jizhe; Huang, Qunying; Liu, Kai; Li, Zhenlong; Hassan, Mohammed Anowarul; Jin, Baoxuan

    2016-01-01

    Dust storm has serious disastrous impacts on environment, human health, and assets. The developments and applications of dust storm models have contributed significantly to better understand and predict the distribution, intensity and structure of dust storms. However, dust storm simulation is a data and computing intensive process. To improve the computing performance, high performance computing has been widely adopted by dividing the entire study area into multiple subdomains and allocating each subdomain on different computing nodes in a parallel fashion. Inappropriate allocation may introduce imbalanced task loads and unnecessary communications among computing nodes. Therefore, allocation is a key factor that may impact the efficiency of parallel process. An allocation algorithm is expected to consider the computing cost and communication cost for each computing node to minimize total execution time and reduce overall communication cost for the entire simulation. This research introduces three algorithms to optimize the allocation by considering the spatial and communicational constraints: 1) an Integer Linear Programming (ILP) based algorithm from combinational optimization perspective; 2) a K-Means and Kernighan-Lin combined heuristic algorithm (K&K) integrating geometric and coordinate-free methods by merging local and global partitioning; 3) an automatic seeded region growing based geometric and local partitioning algorithm (ASRG). The performance and effectiveness of the three algorithms are compared based on different factors. Further, we adopt the K&K algorithm as the demonstrated algorithm for the experiment of dust model simulation with the non-hydrostatic mesoscale model (NMM-dust) and compared the performance with the MPI default sequential allocation. The results demonstrate that K&K method significantly improves the simulation performance with better subdomain allocation. This method can also be adopted for other relevant atmospheric and numerical

  11. The origin, evolution, and trajectory of large dust storms on Mars during Mars years 24-30 (1999-2011)

    Science.gov (United States)

    Wang, Huiqun; Richardson, Mark I.

    2015-05-01

    Mars Daily Global Maps (MDGM) derived from the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) and Mars Reconnaissance Orbiter (MRO) Mars Color Imager (MARCI) are used to study the distribution and evolution of large dust storms over the period from Mars years 24-30 (1999-2001). Large storms are defined here as discrete dust events visible in image sequences extending over at least 5 sols (Mars days) and where the dust covers areas beyond the origination region. A total of 65 large dust storms meeting these criteria are identified during the observational period and all are observed during the Ls = 135-30° seasonal window. Dust storms originating in the northern and southern hemispheres appear to form two distinct families. All but two of the storms originating in the northern hemisphere are observed in two seasonal windows at Ls = 180-240° and Ls = 305-350°; while all but two of those originating in the southern hemisphere are observed during Ls = 135-245°. None of the large dust storms originating in the northern hemisphere are observed to develop to global scale, but some of them develop into large regional storms with peak area >1 × 107 km2 and duration on the order of several weeks. In comparison, large dust storms originating in the southern hemisphere are typically much smaller, except notably in the two cases that expanded to global scale (the 2001 and 2007 global storms). Distinct locations of preferred storm origination emerge from the dust storm image sequences, including Acidalia, Utopia, Arcadia and Hellas. A route (trajectory) 'graph' for the observed sequences is provided. The routes are highly asymmetric between the two hemispheres. In the south, for non-global dust storms, the main routes are primarily oriented eastwest, whereas in the north, the routes are primarily north-south and zonally-concentrated into meridional channels. In a few impressive cases, storms originating in the northern hemisphere are observed to "flush" through

  12. Legal immigrants: invasion of alien microbial communities during winter occurring desert dust storms.

    Science.gov (United States)

    Weil, Tobias; De Filippo, Carlotta; Albanese, Davide; Donati, Claudio; Pindo, Massimo; Pavarini, Lorenzo; Carotenuto, Federico; Pasqui, Massimiliano; Poto, Luisa; Gabrieli, Jacopo; Barbante, Carlo; Sattler, Birgit; Cavalieri, Duccio; Miglietta, Franco

    2017-03-10

    A critical aspect regarding the global dispersion of pathogenic microorganisms is associated with atmospheric movement of soil particles. Especially, desert dust storms can transport alien microorganisms over continental scales and can deposit them in sensitive sink habitats. In winter 2014, the largest ever recorded Saharan dust event in Italy was efficiently deposited on the Dolomite Alps and was sealed between dust-free snow. This provided us the unique opportunity to overcome difficulties in separating dust associated from "domestic" microbes and thus, to determine with high precision microorganisms transported exclusively by desert dust. Our metagenomic analysis revealed that sandstorms can move not only fractions but rather large parts of entire microbial communities far away from their area of origin and that this microbiota contains several of the most stress-resistant organisms on Earth, including highly destructive fungal and bacterial pathogens. In particular, we provide first evidence that winter-occurring dust depositions can favor a rapid microbial contamination of sensitive sink habitats after snowmelt. Airborne microbial depositions accompanying extreme meteorological events represent a realistic threat for ecosystem and public health. Therefore, monitoring the spread and persistence of storm-travelling alien microbes is a priority while considering future trajectories of climatic anomalies as well as anthropogenically driven changes in land use in the source regions.

  13. The dual effect of vegetation green-up date and strong wind on the return period of spring dust storms.

    Science.gov (United States)

    Feng, Jieling; Li, Ning; Zhang, Zhengtao; Chen, Xi

    2017-08-15

    Vegetation phenology changes have been widely applied in the disaster risk assessments of the spring dust storms, and vegetation green-up date shifts have a strong influence on dust storms. However, the effect of earlier vegetation green-up dates due to climate warming on the evaluation of dust storms return periods remains an important, but poorly understood issue. In this study, we evaluate the spring dust storm return period (February to June) in Inner Mongolia, Northern China, using 165 observations of severe spring dust storm events from 16 weather stations, and regional vegetation green-up dates as an integrated factor from NDVI (Normalized Difference Vegetation Index), covering a period from 1982 to 2007, by building the bivariate Copula model. We found that the joint return period showed better fitting results than without considering the integrated factor when the actual dust storm return period is longer than 2years. Also, for extremely severe dust storm events, the gap between simulation result and actual return period can be narrowed up to 0.4888years by using integrated factor. Furthermore, the risk map based on the return period results shows that the Mandula, Zhurihe, Sunitezuoqi, Narenbaolige stations are identified as high risk areas. In this study area, land surface is extensively covered by grasses and shrubs, vegetation green-up date can play a significant role in restraining spring dust storm outbreaks. Therefore, we suggest that Copula method can become a useful tool for joint return period evaluation and risk analysis of severe dust storms. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Improving Short-Range Ensemble Kalman Storm Surge Forecasting Using Robust Adaptive Inflation

    KAUST Repository

    Altaf, Muhammad

    2013-08-01

    This paper presents a robust ensemble filtering methodology for storm surge forecasting based on the singular evolutive interpolated Kalman (SEIK) filter, which has been implemented in the framework of the H∞ filter. By design, an H∞ filter is more robust than the common Kalman filter in the sense that the estimation error in the H∞ filter has, in general, a finite growth rate with respect to the uncertainties in assimilation. The computational hydrodynamical model used in this study is the Advanced Circulation (ADCIRC) model. The authors assimilate data obtained from Hurricanes Katrina and Ike as test cases. The results clearly show that the H∞-based SEIK filter provides more accurate short-range forecasts of storm surge compared to recently reported data assimilation results resulting from the standard SEIK filter.

  15. Dust storms and loess accumulation on the Tibetan Plateau:A case study of dust event on 4 March 2003 in Lhasa

    Institute of Scientific and Technical Information of China (English)

    FANG Xiaomin; HAN Yongxiang; MA Jinghui; SONG Lianchun; YANG Shengli; ZHANG Xiaoye

    2004-01-01

    Whether the Tibetan Plateau is a significant dust source area is of great importance, because this is related to the understanding of sources, accumulation and environmental effects of dusts on the Tibetan Plateau and in the Far East-Pacific Ocean regions as well as to the evolution of coupling of the Tibetan Plateau and atmosphere-ocean continent exchange. Synoptic dynamics and remote sensing tracing of a dust storm on 3 to 5 March, 2003 in Lhasa on South Tibet demonstrate that the Tibetan Plateau possesses all factors and conditions of generating dust storms. Accom panied with this dust storm is a strong ascending stream on the Plateau which has raised various sizes of dust particles into different levels. The lifted coarse particles were largely fallen down and accumulated as loess on the eastern Tibetan Plateau, and the fine particles were translated by the west erly jet and subsided in the northern Pacific Ocean. The spatial-temporal distribution of dust-storms between years 1961 and 2000 on the Plateau shows that dust-storms mainly occur in winter and early spring with high frequency, and the path of dust storm moves gradually from south to north, which is closely coupled with the northward moving of the westerly jet from winter to spring over the Tibetan Plateau. Compared with other twelve dust source areas in China, the Tibetan Plateau is one of the key dust source areas for the long-distance transport because its high occurring frequency and elevation cause fine particles easily to be lifted into the zone of the westerly jet.

  16. Impacts of crystal metal on secondary aliphatic amine aerosol formation during dust storm episodes in Beijing

    Science.gov (United States)

    Liu, Qingyang; Bei, Yiling

    2016-03-01

    Trimethylamine (TMA) enters the atmosphere from a variety of sources and is a ubiquitous atmospheric organic base. The atmospheric reaction mechanism of TMA with key atmospheric oxidants is important to predict its distribution and environmental behavior in the particle phase. While previous studies have extensively focused on the production of particle amine salts (i.e. trimethylamine-N-oxide (TMAO)) using chamber experiments, the atmospheric behavior of TMAO in the environment is still poorly understood. Ambient fine particulate matter (PM2.5) was collected at two sampling sites in Beijing from March 10 to May 10, 2012. We analyzed the samples for water-soluble ions, crystal metals, TMA, and TMAO. Water-soluble ions (e.g. SO42-, NO3-, NH4+), TMA, and TMAO were measured using ion chromatography, while crystal metal (e.g. Al, Fe, Mn) in PM2.5 was quantified by inductively coupled plasma mass spectrometry (ICP-MS). Two dust storms (DS) occurred during the sampling period on March 28 and April 28. Mineral dust impacted PM2.5 mass and composition greatly during dust storm days, as it contributed approximately 1.2-4.0 times greater on dust storm days versus non-dust storm days. We found TMAO concentrations were highly associated with aluminum in PM2.5. Further, we applied the density functional theory (DFT) method to confirm that aluminum plays a catalytic effect in the reaction of TMA with ozone (O3). Our work improves understanding of the effect of crystal metals on secondary aliphatic amine aerosol formation in the atmosphere.

  17. Development of an operational national storm tide forecasting system for Australia.

    Science.gov (United States)

    Allen, S. C.; Colberg, F.; Freeman, J.; Sims, H.; Greenslade, D. J.; Taylor, A.

    2016-12-01

    A high proportion of the Australian population live near the coast and many are vulnerable to impacts from extreme sea levels. Extreme sea levels can be due to a number of physical processes, such as tides, storms, inter-annual variability and sea level rise. Here, we focus on changes of coastal sea levels due to wind stress, atmospheric pressure effects, astronomical tides and wave action. These are commonly known as storm tides. A modeling system is currently being developed to provide routine deterministic forecasts of weather-induced sea level variability for the Australian coastline. These forecasts can provide guidance as to whether alerts need to be issued for extreme sea level events. This system will serve as a separate and contrasting system to an event-driven ensemble-based tropical storm surge system that is also currently under development at the Bureau of Meteorology. This presentation will outline the research and development undertaken to produce the national storm tide system. This paper will outline model configuration, forcing and outputs. The effects of wave set-up are included in post processing. Interaction with tides is also examined. Details of testing and verification are included through simulation of past events. Lastly, there will be a brief description of how it is intended to be run operationally.

  18. Forecasting severe ice storms using numerical weather prediction: the March 2010 Newfoundland event

    Directory of Open Access Journals (Sweden)

    J. Hosek

    2011-02-01

    Full Text Available The northeast coast of North America is frequently hit by severe ice storms. These freezing rain events can produce large ice accretions that damage structures, frequently power transmission and distribution infrastructure. For this reason, it is highly desirable to model and forecast such icing events, so that the consequent damages can be prevented or mitigated. The case study presented in this paper focuses on the March 2010 ice storm event that took place in eastern Newfoundland. We apply a combination of a numerical weather prediction model and an ice accretion algorithm to simulate a forecast of this event.

    The main goals of this study are to compare the simulated meteorological variables to observations, and to assess the ability of the model to accurately predict the ice accretion load for different forecast horizons. The duration and timing of the freezing rain event that occurred between the night of 4 March and the morning of 6 March was simulated well in all model runs. The total precipitation amounts in the model, however, differed by up to a factor of two from the observations. The accuracy of the model air temperature strongly depended on the forecast horizon, but it was acceptable for all simulation runs. The simulated accretion loads were also compared to the design values for power delivery structures in the region. The results indicated that the simulated values exceeded design criteria in the areas of reported damage and power outages.

  19. Forecasting severe ice storms using numerical weather prediction: the March 2010 Newfoundland event

    Science.gov (United States)

    Hosek, J.; Musilek, P.; Lozowski, E.; Pytlak, P.

    2011-02-01

    The northeast coast of North America is frequently hit by severe ice storms. These freezing rain events can produce large ice accretions that damage structures, frequently power transmission and distribution infrastructure. For this reason, it is highly desirable to model and forecast such icing events, so that the consequent damages can be prevented or mitigated. The case study presented in this paper focuses on the March 2010 ice storm event that took place in eastern Newfoundland. We apply a combination of a numerical weather prediction model and an ice accretion algorithm to simulate a forecast of this event. The main goals of this study are to compare the simulated meteorological variables to observations, and to assess the ability of the model to accurately predict the ice accretion load for different forecast horizons. The duration and timing of the freezing rain event that occurred between the night of 4 March and the morning of 6 March was simulated well in all model runs. The total precipitation amounts in the model, however, differed by up to a factor of two from the observations. The accuracy of the model air temperature strongly depended on the forecast horizon, but it was acceptable for all simulation runs. The simulated accretion loads were also compared to the design values for power delivery structures in the region. The results indicated that the simulated values exceeded design criteria in the areas of reported damage and power outages.

  20. An analysis of uncertainties and skill in forecasts of winter storm losses

    Science.gov (United States)

    Pardowitz, Tobias; Osinski, Robert; Kruschke, Tim; Ulbrich, Uwe

    2016-11-01

    This paper describes an approach to derive probabilistic predictions of local winter storm damage occurrences from a global medium-range ensemble prediction system (EPS). Predictions of storm damage occurrences are subject to large uncertainty due to meteorological forecast uncertainty (typically addressed by means of ensemble predictions) and uncertainties in modelling weather impacts. The latter uncertainty arises from the fact that local vulnerabilities are not known in sufficient detail to allow for a deterministic prediction of damages, even if the forecasted gust wind speed contains no uncertainty. Thus, to estimate the damage model uncertainty, a statistical model based on logistic regression analysis is employed, relating meteorological analyses to historical damage records. A quantification of the two individual contributions (meteorological and damage model uncertainty) to the total forecast uncertainty is achieved by neglecting individual uncertainty sources and analysing resulting predictions. Results show an increase in forecast skill measured by means of a reduced Brier score if both meteorological and damage model uncertainties are taken into account. It is demonstrated that skilful predictions on district level (dividing the area of Germany into 439 administrative districts) are possible on lead times of several days. Skill is increased through the application of a proper ensemble calibration method, extending the range of lead times for which skilful damage predictions can be made.

  1. Estimation of the Threshold Friction Velocities over Various Dust Storm Source Areas in Northwest China

    Institute of Scientific and Technical Information of China (English)

    ZHU Hao; ZHANG Hongsheng

    2010-01-01

    The emission of dust particles into the atmosphere is governed by the aerodynamic and resistant factors, which are quantified by the friction velocity u. and the threshold friction velocity u*t, respectively. The threshold friction velocity u*t influences the vertical dust flux and dust transport. Based on the micro-meteorological data obtained in the springs of 2004 and 2006 over Hunshandake desert area, Loess Plateau, and Gobi desert area, the relationship between dust concentration and friction velocity for the dust events that occurred over Hunshandake desert area was investigated, and the threshold friction velocities over the three different dust source areas were estimated. The results show that the value of dust concentration is low during the pre-emission stage of a dust storm event, and the rapid increase of friction velocity provides favor-able dynamic conditions for dust emission. During the dust emission stage, the dust concentration increases sharply due to mechanical and thermal turbulent mixing. At the calm-down stage, the dust concentration drops nearly linearly with the decreasing friction velocity, on account of the gravitational deposition of larger dust particles. When the dust concentration is higher than 200 μgm-3, it is considered as a dust emission process. According to the criteria, the values of threshold friction velocity over Hunshandake desert area and Gobi region are 0.6 and 0.45 m s-1, respectively. The threshold friction velocity over Loess Plateau depends on the wind direction, due to the complex terrain and inhomogeneous surface. The northwest wind shows the effects of the Mu Us desert in the northwest. The corresponding u*t is 0.35 m s-1. The south wind exhibits the characteristics of the Loess hilly dunes in the south, and the u*t is 0.7 m s-1. The large roughness length of the Loess hilly dunes and the large inter-particle cohesion for the clay soil texture increases the local friction velocity. Different threshold friction

  2. A simple method of observation impact analysis for operational storm surge forecasting systems

    Science.gov (United States)

    Sumihar, Julius; Verlaan, Martin

    2016-04-01

    In this work, a simple method is developed for analyzing the impact of assimilating observations in improving forecast accuracy of a model. The method simply makes use of observation time series and the corresponding model output that are generated without data assimilation. These two time series are usually available in an operational database. The method is therefore easy to implement. Moreover, it can be used before actually implementing any data assimilation to the forecasting system. In this respect, it can be used as a tool for designing a data assimilation system, namely for searching for an optimal observing network. The method can also be used as a diagnostic tool, for example, for evaluating an existing operational data assimilation system to check if all observations are contributing positively to the forecast accuracy. The method has been validated with some twin experiments using a simple one-dimensional advection model as well as with an operational storm surge forecasting system based on the Dutch Continental Shelf model version 5 (DCSMv5). It has been applied for evaluating the impact of observations in the operational data assimilation system with DCSMv5 and for designing a data assimilation system for the new model DCSMv6. References: Verlaan, M. and J. Sumihar (2016), Observation impact analysis methods for storm surge forecasting systems, Ocean Dynamics, ODYN-D-15-00061R1 (in press) Zijl, F., J. Sumihar, and M. Verlaan (2015), Application of data assimilation for improved operational water level forecasting of the northwest European shelf and North Sea, Ocean Dynamics, 65, Issue 12, pp 1699-1716.

  3. Influence of tropical storms in the Northern Indian Ocean on dust entrainment and long-range transport.

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaswamy, V.

    Ninety five tropical cyclonic events (tropical storms, depressions and cyclones) between 2001 and 2010 were studied to determine their impact on dust outbreaks and long-range transport over the northern Indian Ocean and south Asia. In addition...

  4. Use of SEVIRI images and derived products in a WMO Sand and dust Storm Warning System

    Energy Technology Data Exchange (ETDEWEB)

    MartInez, M A; Ruiz, J; Cuevas, E [Agencia Estatal de MeteorologIa (AEMET) (Spain)], E-mail: mig@inm.es

    2009-03-01

    The Visible/IR images of SEVIRI (Spinning Enhanced Visible and Infrared Imager), on board Meteosat Second Generation (MSG) satellites, are used to monitor dust events. Satellite-based detection of dust is a difficult problem due in part to the observing-system limitations. The main difficulty is that the dust can be confused with water/ice clouds. SEVIRI is not as optimal for the viewing of dust as SEAWIFS or MODIS, due to the fact that both of them count with additional short-wavelength channels. However, the SEVIRI 15-minute loop images can detect small dust plumes as well as subtle changes from one image to the next. A description of how the AEMET, former INM, is developing the environment to support MSG satellite imagery to the WMO/GEO Sand and Dust Storm Warning System (SDS WS) for Europe, Africa and Middle East Regional Centre will be briefly presented, together with some on-going operational developments to best monitor dust events.

  5. The effects of dust storms on quality of life of allergic patients with or without asthma.

    Science.gov (United States)

    Soy, Fatih Kemal; Yazıcı, Haşmet; Kulduk, Erkan; Dündar, Rıza; Gülen, Şule Taş; Doğan, Sedat; Can, İlknur Haberal

    2016-01-01

    This study aims to investigate the quality of life of allergic patients with or without asthma during dust storms. A total of 148 allergic patients (66 males, 82 females; mean age 35.7±15.5 years; range 18 to 65 years) were classified as those with (group 1, n=80) or without (group 2, n=68) concomitant asthma between January 2012 and January 2013. The quality of life [Short Form-36 (SF-36)] scores, Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), nasal symptom and visual analog scale (VAS) scores at the time of diagnosis were obtained. The particulate matter (PM10) and sulfur dioxide (SO2) values of that day from the General Directorate of Meteorology were recorded. The day of dust storm and PM10 and SO2 measurements along with SF-36, RQLQ, nasal symptom and VAS scores were recorded again. The absolute change in the RQLQ subparameters including eye and nasal symptoms, practical problems and global scores was statistically significant (p=0.022, p=0.036, p=0.026 and p=0.032, respectively). There were statistically significant changes in the SF-36 subgroups of general health, physical functioning, vitality, and mental health (p=0.026, p=0.042, p=0.008 and p=0.026, respectively). In the multivariate logistic regression model, specific and general quality of life was 4.6 times worse in RQLQ and 3.8 times in SF-36 after the dust storm in patients with asthma, while 2.1 times worse in RQLQ and 1.9 times in SF-36 in patients with pure allergic rhinitis. The attributable risk of asthma was found to be 2.5 times higher in RQLQ and 1.9 times higher in SF-36. Dust storms may deteriorate the quality of life of patients with allergic rhinitis and asthma and lead to related personal and societal problems.

  6. The return periods and risk assessment of severe dust storms in Inner Mongolia with consideration of the main contributing factors.

    Science.gov (United States)

    Liu, Xueqin; Li, Ning; Xie, Wei; Wu, Jidong; Zhang, Peng; Ji, Zhonghui

    2012-09-01

    This study presents a methodology for return period analysis and risk assessment of severe dust storm disaster. Meteorological observation data, soil moisture data, and remote sensing data from 30 meteorological stations in Inner Mongolia (western China) from 1985 to 2006 were used for the study. A composite index of severe dust storm disaster (Index I (SDS)) based on the influence mechanisms of the main contributing factors was developed by using the analytic hierarchy process and the weighted comprehensive method, and the hazard risk curves (i.e., the transcendental probability curves of I (SDS)) for the 30 stations were established using the parameter estimation method. We then analyzed the risk of the occurrence of severe dust storm under different scenarios of 5-, 10-, 20-, and 50-year return periods. The results show that the risk decreased from west to east across Inner Mongolia, and there are four severe dust storm occurrence peak value centers, including Guaizihu, Jilantai, Hailisu, and Zhurihe-Erenhot. The severity of dust storms in seven places will be intolerable in the 50-year return period scenario and in three places in the 20-year return period scenario. These results indicate that these locations should concentrate forces on disaster prevention, monitoring, and early warning. The I (SDS) was developed as an easily understandable tool useful for the assessment and comparison of the relative risk of severe dust storm disasters in different areas. The risk assessment was specifically intended to support local and national government agencies in their management of severe dust storm disasters in their efforts to (1) make resource allocation decisions, (2) make high-level planning decisions, and (3) raise public awareness of severe dust storm risk.

  7. Dust storm contributions to airborne particulate matter in Reykjavík, Iceland

    Science.gov (United States)

    Thorsteinsson, Throstur; Gísladóttir, Guđrún; Bullard, Joanna; McTainsh, Grant

    2011-10-01

    Episodes of high levels of particulate matter (PM) in Reykjavík occur several times a year. The main sources of daily variation in PM are traffic or highly localized (e.g. construction) sources, however several episodes have been identified where these are not the cause. Examining PM10 (diameter 50-100 μg m-3; 30-min average), demonstrates that dust storms are the source of these increased levels of PM10. Since satellite coverage is sparse, visual confirmation of many such peaks in PM10 cannot be achieved. The level of pollution measured in Reykjavík during dust storms indicates that at least 200 kg s-1 of PM10 sized material is being eroded and transported away from sand plains ˜110 km away - this equates to an emission rate of 35 g m2 h-1. The source regions for dust storms in Iceland are the sandur areas on the southern coast of Iceland, and regions close to the glaciers. With climate warming, and fast retreating glaciers, the potential source regions in Iceland are rapidly increasing.

  8. A comprehensive characterisation of Asian dust storm particles: chemical composition, reactivity to SO2, and hygroscopic property

    Directory of Open Access Journals (Sweden)

    H. He

    2010-04-01

    Full Text Available Mineral dust comprises of a significant fraction of the globe's aerosol loading. Yet it remains the largest uncertainty in future climate predictions due to the complexity in its components and physico-chemical properties. Multi-analysis methods, including SEM-EDX, FTIR, BET, TPD/mass, and Knudsen cell/mass, were used in the present study to characterise Asian dust storm particles. The morphology, element fraction, source distribution, true uptake coefficient of SO2 and hygroscopic behaviour were studied. The major components of Asian dust storm particles were found to consist of aluminosilicate, SiO2, and CaCO3, which were coated with organic compounds and inorganic nitrate. The dust storm particles have a low reactivity to SO2 (true uptake coefficient of 5.767×10−6 which limits the conversion of SO2 to sulfate during a dust storm period. The low reactivity also demonstrated that the heterogeneous reaction of SO2, in both dry and humid air conditions, had little effect on the hygroscopic behaviour of the dust particles. These results indicate that the impact of dust storms on atmospheric SO2 removal should not be overestimated.

  9. Aerosols properties during dust-storm episodes over Jaipur, Northwestern India

    Science.gov (United States)

    Payra, Swagata; Verma, Sunita; Prakash, Divya; Kumar, Pramod; Soni, Manish; Holben, Brent

    2013-05-01

    Continuous routine aerosol measurements have been carried out at Jaipur (Rajasthan, Northwestern India) since April 2009 with a CIMEL sun photometer integrated in the global Aerosols Robotic Network (AERONET) program. The present study investigates the aerosol properties during dust storm episodes over Jaipur, Northwestern India. A series of high dust storms were identified as indicated by high values of aerosols optical thickness (AOT) with a significant drop in angstrom exponent values (nearly zero and negative). Consequently, a progressive increase in Single Scattering Albedo (SSA440 nm = 0.89, SSA675 nm = 0.95, SSA870 nm = 0.97, SSA1020 nm = 0.976) suggests more scattering nature of regional aerosols associated with abundant dust loading. Trajectories back in time showed that the air collected in Jaipur during dust period originated from desert regions in the western part of India. Additionally, a comparative analysis of the mean AOT derived from satellite data and Potential Source Contribution Function (PSCF) analysis helped to understand the source region of these particles.

  10. Statistical Guidance on Seasonal Forecast of Korean Dust Days over South Korea in the Springtime

    Institute of Scientific and Technical Information of China (English)

    Keon Tae SOHN

    2013-01-01

    This study aimed to develop the seasonal forecast models of Korean dust days over South Korea in the springtime.Forecast mode was a ternary forecast (below normal,normal,above normal) which was classified based on the mean and the standard deviation of Korean dust days for a period of 30 years (1981-2010).In this study,we used three kinds of monthly data:the Korean dust days observed in South Korea,the National Center for Environmental Prediction in National Center for Atmospheric Research (NCEP/NCAR) reanalysis data for meteorological factors over source regions of Asian dust,and the large-scale climate indices offered from the Climate Diagnostic Center and Climate Prediction Center in NOAA.Forecast guidance consisted of two components; ordinal logistic regression model to generate trinomial distributions,and conversion algorithm to generate ternary forecast by two thresholds.Forecast guidance was proposed for each month separately and its predictability was evaluated based on skill scores.

  11. Surface Wind Stresses and Triggering of Global Dust Storms on Mars

    Science.gov (United States)

    Mischna, Michael A.; Shirley, James H.

    2016-10-01

    Global dust storms on Mars occur during summer in the southern hemisphere, but their occurrence in some years and not in others has stubbornly eluded explanation. Shirley (2016, in review, and at arxiv.org/abs/1605.02707) and Mischna and Shirley (2016, in revision, and at arxiv.org/abs/1602.09137) have demonstrated the role of a so-called "coupling term acceleration" (CTA) in modifying the Mars global circulation through potential exchange of Mars' orbital and rotational momenta. The CTA has been incorporated into the MarsWRF general circulation model (GCM), which reveals distinct changes to the circulation due to the CTA, leading to conditions favorable to GDS formation in all years in which perihelion season GDS were observed, and conditions unfavorable in nearly all other years. These circulation changes reveal themselves, in part, through changes in surface wind stress, which is a strong function of near-surface wind speed. We present additional analysis of these results for the past years with perihelion season GDS (7 in total) showing commonalities in the evolution of surface stresses in the season leading up to GDS initiation. Specifically, the enhancement of surface stress during this pre-storm season, arising from the orbit-spin coupling in years with perihelion season storms, presents some common patterns. Among these are the rate and duration of increase of wind stress, and the minimum level of enhancement from the CTA that is apparently required in these years prior to initiation of a GDS. Previously we assessed changes in surface stress using a simple, dust-free model atmosphere. Here, further, we perform parallel simulations for MY 24-27 using realistic dust profiles from TES limb observations. The inclusion of dust in the GCM modifies atmospheric opacity and will alter global atmospheric temperatures leading to a markedly different atmospheric state. We find that the inclusion of dust in the atmosphere reduces the magnitude of surface stresses as

  12. The Challenge of Modelling the Meteorology of Dust Emission: Lessons Learned from the Desert Storms Project

    Science.gov (United States)

    Knippertz, Peter; Marsham, John H.; Cowie, Sophie; Fiedler, Stephanie; Heinold, Bernd; Jemmett-Smith, Bradley; Pantillon, Florian; Schepanski, Kerstin; Roberts, Alexander; Pope, Richard; Gilkeson, Carl; Hubel, Eva

    2016-04-01

    Mineral dust plays an important role in the Earth system, but a reliable quantification of the global dust budget is still not possible due to a lack of observations and insufficient representation of relevant processes in climate and weather models. Five years ago, the Desert Storms project funded by the European Research Council set out to reduce these uncertainties. Its aims were to (1) improve the understanding of key meteorological mechanisms of peak wind generation in dust emission regions (particularly in northern Africa), (2) assess their relative importance, (3) evaluate their representation in models, (4) determine model sensitivities with respect to resolution and model physics, and (5) explore the usefulness of new approaches for model improvements. Here we give an overview of the most significant findings: (1) The morning breakdown of nocturnal low-level jets is an important emission mechanism, but details depend crucially on nighttime stability, which is often badly handled by models. (2) Convective cold pools are a key control on summertime dust emission over northern Africa, directly and through their influence on the heat low; they are severely misrepresented by models using parameterized convection. A new scheme based on downdraft mass flux has been developed that can mitigate this problem. (3) Mobile cyclones make a relatively unimportant contribution, except for northeastern Africa in spring. (4) A new global climatology of dust devils identifies local hotspots but suggests a minor contribution to the global dust budget in contrast to previous studies. A new dust-devil parameterization based on data from large-eddy simulations will be presented. (5) The lack of sufficient observations and misrepresentation of physical processes lead to a considerable uncertainty and biases in (re)analysis products. (6) Variations in vegetation-related surface roughness create small-scale wind variability and support long-term dust trends in semi-arid areas.

  13. Ten-year operational dust forecasting - Recent model development and future plans

    Energy Technology Data Exchange (ETDEWEB)

    Kallos, G; Spyrou, C; Astitha, M; Mitsakou, C; Solomos, S; Kushta, J; Pytharoulis, I; Katsafados, P; Mavromatidis, E; Papantoniou, N; Vlastou, G [University of Athens, School of Physics, Atmospheric Modeling and Weather Forecasting Group - UOA/AM and WFG, University Campus, Bldg. PHYS-V, Athens 15784 (Greece)], E-mail: kallos@mg.uoa.gr

    2009-03-01

    The Sahara desert is one of the major sources of mineral dust on Earth, producing up to 2x10{sup 8} t yr-{sup 1}. A combined effort has been devoted during the last ten years at the University of Athens (UOA) from the Atmospheric Modeling and Weather Forecasting Group (AM and WFG) to the development of an analysis and forecasting tool that will provide early warning of Saharan dust outbreaks. The developed tool is the SKIRON limited-area forecasting system, based on the Eta limited area modeling system with embedded algorithms describing the dust cycle. A new version of the model is currently available, with extra features like eight-size particle bins, radiative transfer corrections, new dust source identification and utilization of rocky soil characterization and incorporation of more accurate deposition schemes. The new version of SKIRON modeling system is coupled with the photochemical model CAMx in order to study processes like the shading effect of dust particles on photochemical processes and the production of second and third generation of aerosols. Moreover, another new development in the AM and WFG is based on the RAMS model, with the incorporation of processes like dust and sea-salt production, gas and aqueous phase chemistry and particle formation. In this study, the major characteristics of the developed (and under development) modeling systems are presented, as well as the spatiotemporal distribution of the transported dust amounts, the interaction with anthropogenically-produced particles and the potential implications on radiative transfer.

  14. Effect of Asian dust storms on mortality in three Asian cities

    Science.gov (United States)

    Lee, Hyewon; Honda, Yasushi; Lim, Youn-Hee; Guo, Yue Leon; Hashizume, Masahiro; Kim, Ho

    2014-06-01

    Asian dust storms (ADS) have affected several Asian countries and have been a major concern due to adverse effects on public health. The occurrence of ADS differs in each country based on geographical features and distance from the storms' origin. Many studies have reported significant associations between ADS and morbidity. However, regarding the association between ADS and mortality, only a few studies have found statistically significant ADS effects in Korea, Taiwan and Japan. Accordingly, this study aimed to examine the effects of ADS on daily mortality in three Asian cities (Seoul, South Korea; Taipei, Taiwan; and Kitakyushu, Japan) and to explore the differences in the extent of effects in each city. We performed time-series analyses using a generalized additive model (GAM) with Quasi-Poisson regressions. Deaths due to accidents or external causes were excluded. We used a dummy variable as an indicator of ADS and considered lag effects of ADS. Stratified analyses by disease and age and sensitivity analyses controlling for NO2, SO2, and PM10 were also conducted respectively. Additionally, influenza epidemics were adjusted for considering seasonal patterns, and a meta-analysis was performed. We reported results as excess mortality by percentage due to Asian dust storms. We found significant excess mortality in Seoul and Kitakyushu as follows. In Seoul, ADS showed adverse effects on mortality under 65 years old (lag 2: 4.44%, lag 3: 5%, lag 4: 4.39%). In Kitakyushu, ADS had adverse effects on respiratory mortality (lag 2: 18.82%). Contradictory to results in Seoul and Kitakyushu, ADS seemed to have a protective effect in Taipei: total non-accidental mortality (lag 0: -2.77%, lag 1: -3.24%), mortality over 65 years old (lag 0: -3.35%, lag 1: -3.29%) and respiratory mortality (lag 0: -10.62%, lag 1: -9.67%). Sensitivity analyses showed similar findings as the main results. Our findings suggest that ADS may affect mortality in several Asian cities, and that a dust

  15. Adapting NEMO for use as the UK operational storm surge forecasting model

    Science.gov (United States)

    Furner, Rachel; Williams, Jane; Horsburgh, Kevin; Saulter, Andrew

    2016-04-01

    The United Kingdom is an area vulnerable to damage due to storm surges, particularly the East Coast which suffered losses estimated at over £1 billion during the North Sea surge event of the 5th and 6th December 2013. Accurate forecasting of storm surge events for this region is crucial to enable government agencies to assess the risk of overtopping of coastal defences so they can respond appropriately, minimising risk to life and infrastructure. There has been an operational storm surge forecast service for this region since 1978, using a numerical model developed by the National Oceanography Centre (NOC) and run at the UK Met Office. This is also implemented as part of an ensemble prediction system, using perturbed atmospheric forcing to produce an ensemble surge forecast. In order to ensure efficient use of future supercomputer developments and to create synergy with existing operational coastal ocean models the Met Office and NOC have begun a joint project transitioning the storm surge forecast system from the current CS3X code base to a configuration based on the Nucleus for European Modelling of the Ocean (NEMO). This work involves both adapting NEMO to add functionality, such as allowing the drying out of ocean cells and changes allowing NEMO to run efficiently as a two-dimensional, barotropic model. As the ensemble surge forecast system is run with 12 members 4 times a day computational efficiency is of high importance. Upon completion this project will enable interesting scientific comparisons to be made between a NEMO based surge model and the full three-dimensional baroclinic NEMO based models currently run within the Met Office, facilitating assessment of the impact of baroclinic processes, and vertical resolution on sea surface height forecasts. Moving to a NEMO code base will also allow many future developments to be more easily used within the storm surge model due to the wide range of options which currently exist within NEMO or are planned for

  16. 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.

  17. 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.

  18. A new deterministic Ensemble Kalman Filter with one-step-ahead smoothing for storm surge forecasting

    KAUST Repository

    Raboudi, Naila

    2016-11-01

    by performing assimilation experiments with the highly nonlinear Lorenz model and a realistic setting of the Advanced Circulation (ADCIRC) model configured for storm surge forecasting in the Gulf of Mexico during Hurricane Ike.

  19. The global dispersion of pathogenic microorganisms by dust storms and its relevance to agriculture: Chapter 1

    Science.gov (United States)

    Gonzalez-Martin, Cristina; Teigell-Perez, Nuria; Valladares, Basilio; Griffin, Dale W.

    2014-01-01

    Dust storms move an estimated 500–5000 Tg of soil through Earth’s atmosphere every year. Dust-storm transport of topsoils may have positive effects such as fertilization of aquatic and terrestrial ecosystems and the evolution of soils in proximal and distal environments. Negative effects may include the stripping of nutrient-rich topsoils from source regions, sandblasting of plant life in downwind environments, the fertilization of harmful algal blooms, and the transport of toxins (e.g., metals, pesticides, herbicides, etc.) and pathogenic microorganisms. With respect to the long-range dispersion of microorganisms and more specifically pathogens, research is just beginning to demonstrate the quantity and diversity of organisms that can survive this type of transport. Most studies to date have utilized different assays to identify microorganisms and microbial communities using predominately culture-based, and more recently nonculture-based, methodologies. There is a clear need for international-scale research efforts that apply standardized methods to advance this field of science. Here we present a review of dust-borne microorganisms with a focus on their relevance to agronomy.

  20. Oxidant enhancement in martian dust devils and storms: implications for life and habitability.

    Science.gov (United States)

    Atreya, Sushil K; Wong, Ah-San; Renno, Nilton O; Farrell, William M; Delory, Gregory T; Sentman, Davis D; Cummer, Steven A; Marshall, John R; Rafkin, Scot C R; Catling, David C

    2006-06-01

    We investigate a new mechanism for producing oxidants, especially hydrogen peroxide (H2O2), on Mars. Large-scale electrostatic fields generated by charged sand and dust in the martian dust devils and storms, as well as during normal saltation, can induce chemical changes near and above the surface of Mars. The most dramatic effect is found in the production of H2O2 whose atmospheric abundance in the "vapor" phase can exceed 200 times that produced by photochemistry alone. With large electric fields, H2O2 abundance gets large enough for condensation to occur, followed by precipitation out of the atmosphere. Large quantities of H2O2 would then be adsorbed into the regolith, either as solid H2O2 "dust" or as re-evaporated vapor if the solid does not survive as it diffuses from its production region close to the surface. We suggest that this H2O2, or another superoxide processed from it in the surface, may be responsible for scavenging organic material from Mars. The presence of H2O2 in the surface could also accelerate the loss of methane from the atmosphere, thus requiring a larger source for maintaining a steady-state abundance of methane on Mars. The surface oxidants, together with storm electric fields and the harmful ultraviolet radiation that readily passes through the thin martian atmosphere, are likely to render the surface of Mars inhospitable to life as we know it.

  1. Impact of Middle Eastern dust storms on indoor and outdoor composition of bioaerosol

    Science.gov (United States)

    Soleimani, Zahra; Goudarzi, Gholamreza; Sorooshian, Armin; Marzouni, Mohammad Bagherian; Maleki, Heidar

    2016-08-01

    The presence of microbes in airborne aerosol particles, especially dust, is a major public health concern in desert regions. This study is the first of its kind to examine the effect of dust storms on indoor and outdoor microbial air quality at a hospital on the western side of Iran (city of Ahvaz), which is notorious for being highly vulnerable to dust emissions. Air samples were collected inside and outside of the hospital environment for six months, with the unique advantage of this study being that the region and duration of measurements allow for a clear comparison between dusty and normal days. On normal days, the average concentrations (outdoor/indoor) of bacteria and fungi were 423/329 cfu m-3 and 596/386 cfu m-3, respectively, which increased to 1257/406 cfu m-3 and 1116/550 cfu m-3 on dust event days. Indoor/Outdoor ratios for bacteria and fungi are lower on dust event days (0.26-0.60) versus normal days (0.44-0.95). Bacillus spp., Micrococcus spp., Streptomyces spp., and Staphylococcus spp. were the dominant bacteria both indoors and outdoors on normal and dust event days. Gram positive bacteria exhibited higher concentrations than Gram negative bacteria in both outdoor and indoor air samples as well as during both normal and dust event days. The data suggest that Gram positive bacteria are more resistant to undesirable outdoor conditions (e.g., high incident solar radiation) as compared to Gram negative ones. These results have implications for other populated arid regions where more stringent control of indoor air quality can greatly benefit public health.

  2. Electromagnetic wave attenuation due to the charged particles in dust&sand (DUSA) storms

    Science.gov (United States)

    Dou, X. Q.; Xie, L.

    2017-07-01

    In this paper, we calculated the attenuation of the electromagnetic waves (EMWs) propagating through the dust&sand (DUSA) storms using the predicting model based on Mie theory, in which the charges carried on the DUSA particles, the ambient relative humidity (RH) and the particle size distribution are considered simultaneously. It can be found that the charges carried on the DUSA particles and the RH can change the value of the absorption and scattering efficiency, but they can't change the domain attenuation mechanism caused by the DUSA storms in the EMWs frequency regions (3 GHz, 4 GHz), (8 GHz, 40 GHz) and (75 GHz, 100 GHz). Whatever the DUSA storms are formed by equal-size particles or the mixed-size particles, the charge carried on the particle surface and the RH have a significant impact on the attenuation caused by the DUSA storms, and the change ratio of the attenuation caused by the charge or RH depends on the particle size. By the comparison of the calculated attenuation with the measured one, we found that the charges carried on the particles and the RH will be important factors to affect the attenuation of the EMWs.

  3. Usefulness and skill of station-derived predictors in forecasting storm occurrence and intensity

    Science.gov (United States)

    Pucillo, Arturo; Manzato, Agostino

    2013-04-01

    The Friuli Venezia Giulia region (northeastern Italy, hereafter FVG) is an area subject to frequent storm occurrences. The Regional Meteorological Observatory of Friuli Venezia Giulia (hereafter OSMER) manages a spatially dense network of meteorological stations, that provides measures with a maximum sampling frequency of 5 min. Moreover there is a C-band Doppler Polarimetric Radar that provides complete scans every 5 min during the convective events, or every 30 min otherwise. This work aims to characterize the skill of one or more predictors, that are the measurements of such meteorological stations (e.g. wind magnitude, equivalent potential temperature, moisture transport, etc.), when forecasting the highest radar Vertical Maximum Intensity reflectivity (hereafter VMI) measured on the plain and coast of FVG, used as signature of the storm occurrence and intensity. The dataset here used consists of 5-minutes maximum time-resolution VMI (used to define each event) on plain and coast areas of FVG, and 5-minutes time-resolution observations derived from 31 stations, considering a time-lag varying from 30 min to 3 h before the VMI observation. The VMI dataset spans over a period 11 years long (2000-2010) and consists of about 100,000 cases. Both a multiregression study to forecast the maximum VMI value and a classification study of the occurrence of VMI events exceeding certain thresholds have been performed.

  4. The Association between Dust Storms and Daily Non-Accidental Mortality in the United States, 1993–2005

    Science.gov (United States)

    Crooks, James Lewis; Cascio, Wayne E.; Percy, Madelyn S.; Reyes, Jeanette; Neas, Lucas M.; Hilborn, Elizabeth D.

    2016-01-01

    Background: The impact of dust storms on human health has been studied in the context of Asian, Saharan, Arabian, and Australian storms, but there has been no recent population-level epidemiological research on the dust storms in North America. The relevance of dust storms to public health is likely to increase as extreme weather events are predicted to become more frequent with anticipated changes in climate through the 21st century. Objectives: We examined the association between dust storms and county-level non-accidental mortality in the United States from 1993 through 2005. Methods: Dust storm incidence data, including date and approximate location, are taken from the U.S. National Weather Service storm database. County-level mortality data for the years 1993–2005 were acquired from the National Center for Health Statistics. Distributed lag conditional logistic regression models under a time-stratified case-crossover design were used to study the relationship between dust storms and daily mortality counts over the whole United States and in Arizona and California specifically. End points included total non-accidental mortality and three mortality subgroups (cardiovascular, respiratory, and other non-accidental). Results: We estimated that for the United States as a whole, total non-accidental mortality increased by 7.4% (95% CI: 1.6, 13.5; p = 0.011) and 6.7% (95% CI: 1.1, 12.6; p = 0.018) at 2- and 3-day lags, respectively, and by an average of 2.7% (95% CI: 0.4, 5.1; p = 0.023) over lags 0–5 compared with referent days. Significant associations with non-accidental mortality were estimated for California (lag 2 and 0–5 day) and Arizona (lag 3), for cardiovascular mortality in the United States (lag 2) and Arizona (lag 3), and for other non-accidental mortality in California (lags 1–3 and 0–5). Conclusions: Dust storms are associated with increases in lagged non-accidental and cardiovascular mortality. Citation: Crooks JL, Cascio WE, Percy MS, Reyes

  5. Assessment of Vegetation Variation on Primarily Creation Zones of the Dust Storms Around the Euphrates Using Remote Sensing Images

    Directory of Open Access Journals (Sweden)

    Jamil Amanollahi

    2012-06-01

    Full Text Available Recently, period frequency and effect domain of the dust storms that enter Iran from Iraq have increased. In this study, in addition to detecting the creation zones of the dust storms, the effect of vegetation cover variation on their creation was investigated using remote sensing. Moderate resolution image Spectroradiometer (MODIS and Landsat Thematic Mapper (TM5 have been utilized to identify the primarily creation zones of the dust storms and to assess the vegetation cover variation, respectively. Vegetation cover variation was studied using Normalized Differences Vegetation Index (NDVI obtained from band 3 and band 4 of the Landsate satellite. The results showed that the surrounding area of the Euphrates in Syria, the desert in the vicinity of this river in Iraq, including the deserts of Alanbar Province, and the north deserts of Saudi Arabia are the primarily creation zones of the dust storms entering west and south west of Iran. The results of NDVI showed that excluding the deserts in the border of Syria and Iraq, the area with very weak vegetation cover have increased between 2.44% and 20.65% from 1991 to 2009. In the meanwhile, the retention pound surface areas in the south deserts of Syria as well as the deserts in its border with Iraq have decreased 6320 and 4397 hectares, respectively. As it can be concluded from the findings, one of the main environmental parameters initiating these dust storms is the decrease in the vegetation cover in their primarily creation zones.

  6. The Martian annual atmospheric pressure cycle - Years without great dust storms

    Science.gov (United States)

    Tillman, James E.; Johnson, Neal C.; Guttorp, Peter; Percival, Donald B.

    1993-01-01

    A model of the annual cycle of pressure on Mars for a 2-yr period, chosen to include one year at the Viking Lander 2 and to minimize the effect of great dust storms at the 22-deg N Lander 1 site, was developed by weighted least squares fitting of the Viking Lander pressure measurements to an annual mean, and fundamental and the first four harmonics of the annual cycle. Close agreement was obtained between the two years, suggesting that an accurate representation of the annual CO2 condensation-sublimation cycle can be established for such years. This model is proposed as the 'nominal' Martian annual pressure cycle, and applications are suggested.

  7. Improved Satellite Techniques for Monitoring and Forecasting the Transition of Hurricanes to Extratropical Storms

    Science.gov (United States)

    Folmer, Michael; Halverson, Jeffrey; Berndt, Emily; Dunion, Jason; Goodman, Steve; Goldberg, Mitch

    2014-01-01

    The Geostationary Operational Environmental Satellites R-Series (GOES-R) and Joint Polar Satellite System (JPSS) Satellite Proving Grounds have introduced multiple proxy and operational products into operations over the last few years. Some of these products have proven to be useful in current operations at various National Weather Service (NWS) offices and national centers as a first look at future satellite capabilities. Forecasters at the National Hurricane Center (NHC), Ocean Prediction Center (OPC), NESDIS Satellite Analysis Branch (SAB) and the NASA Hurricane and Severe Storms Sentinel (HS3) field campaign have had access to a few of these products to assist in monitoring extratropical transitions of hurricanes. The red, green, blue (RGB) Air Mass product provides forecasters with an enhanced view of various air masses in one complete image to help differentiate between possible stratospheric/tropospheric interactions, moist tropical air masses, and cool, continental/maritime air masses. As a compliment to this product, a new Atmospheric Infrared Sounder (AIRS) and Cross-track Infrared Sounder (CrIS) Ozone product was introduced in the past year to assist in diagnosing the dry air intrusions seen in the RGB Air Mass product. Finally, a lightning density product was introduced to forecasters as a precursor to the new Geostationary Lightning Mapper (GLM) that will be housed on GOES-R, to monitor the most active regions of convection, which might indicate a disruption in the tropical environment and even signal the onset of extratropical transition. This presentation will focus on a few case studies that exhibit extratropical transition and point out the usefulness of these new satellite techniques in aiding forecasters forecast these challenging events.

  8. Characterization and radiative impact of dust aerosols over northwestern part of India: a case study during a severe dust storm

    Science.gov (United States)

    Singh, Atinderpal; Tiwari, Shani; Sharma, Deepti; Singh, Darshan; Tiwari, Suresh; Srivastava, Atul Kumar; Rastogi, Neeraj; Singh, A. K.

    2016-12-01

    The present study focused on examining the impact of a severe dust storm (DS) on aerosol properties over Patiala (30.33°N, 76.4°E), a site located in the northwestern part of India during 20th-23rd March, 2012. On 20th March, average PM10 mass concentration increased abruptly from 182 to 817 µg m-3 along with significant increase in the number density of coarser particles (diameter >0.45 µm). During DS, spectral aerosol optical depth (AOD) increases significantly with more increase at longer wavelengths resulting in weak wavelength dependence (AOD at 380 nm increases by 210 % and at 870 nm by 270 % on 20th March). Significant decrease in Ångström exponent (AE; α 380-870) from 0.56 to 0.11 and fine-mode fraction (FMF; PM2.5/PM10) from 0.49 to 0.25 indicates dominance of coarser particles over the station. Net short wave (SW) radiation flux has been decreased by 20 % and single scattering albedo (SSA675) has been increased from 0.86 (19th March) to 0.90 (20th March). This observation is attributed to additional loading of scattering type aerosols on arrival of DS. Wavelength dependence of SSA reverses during DS and it increases with wavelength due to dominance of coarse-mode particles. Atmospheric aerosol radiative forcing (ATM ARF) during DS ranged from +45 to +77 W m-2, consequently heating the lower atmosphere up to 2.2 K day-1. Significant atmospheric heating rate due to severe dust storm may affect the regional atmospheric dynamics and hence the climate system.

  9. A New Look to Interactions of Saharan Dust with Waves in the Tropical Atlantic Storm Track

    Science.gov (United States)

    Hosseinpour, F.; Wilcox, E. M.; Colarco, P. R.

    2015-12-01

    This study addresses mechanisms of the interactions between light-absorbing aerosols and transient atmospheric waves, including their feedback onto the mean-circulation in one of the most meteorologically sensitive areas of the world: the tropical western African/eastern Atlantic Ocean. Evidence of these interactions are presented based on analyses of an ensemble of NASA satellite data sets, including aerosol optical thickness (AOT) observations from the Moderate Resolution Imaging Spectro-radiometer (MODIS) and the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS), as well as an atmospheric reanalysis from the Modern-Era Retrospective Analysis for Research and Applications (MERRA) and a simulation of The Goddard Chemistry Aerosol Radiation and Transport (GOCART) model. We analyzed the components of the rate of change of eddy kinetic energy (EKE) to explore the possible role of dust aerosol radiative forcing on reinforcing energetic terms associated with the African easterly waves (AEWs) during boreal summer seasons when the activity of AEWs peaks. This study shows that the anomalous perturbations in concentration of dust in the oceanic Saharan Air Layer (OSAL) precede amplified growth and decay of the subsequent waves compared to waves occurring prior to dust outbreaks. The amplified EKE associated with dust outbreaks are followed by seeding of new wave packets through enhanced divergence and convergence of ageostrophic geopotential height fluxes in the tropical Atlantic storm track. Meanwhile, the enhanced forcing of the mean-circulation associated with the increased momentum fluxes of the high frequency eddies at the northern track of AEWs occurs with a time-lag after the peak of dust concentration in the OSAL. We suggest that dust radiative heating in the OSAL may act as an additional energy source to amplify the thermal/mechanical activity of eddies in the northern track of the AEWs.

  10. Forecasting methods for occurrence and magnitude of proton storms with solar hard X rays

    Science.gov (United States)

    Garcia, H. A.

    2004-06-01

    A hard X-ray spectrometer (HXRS) was developed jointly by the National Oceanic and Atmospheric Administration (NOAA) Space Environment Center and the Astronomical Institute of the Czech Republic to determine if proton storms could be forecast with greater accuracies than presently available by the existing methods. The HXRS experiment was conceived as a means of proof testing previously discovered empirical relationships between anomalous hard X-ray spectra of hard X-ray flares and solar energetic proton events (SEPs) for space weather forecasting applications. SEPs are showers of highly energetic electrons and ions, mostly protons, that can reach Earth's vicinity within minutes to hours following a moderate to large flare and have the potential of affecting the performance of civilian, military and research satellites as well as certain surface assets. The primary SEP predictor criterion educed during the present study is the requirement that the spectral index, γ, must decline (harden) to at least <=4 for at least 3 min. Flares meeting this criterion have a high association with SEPs. Flares that fail this criterion do not. Other SEP correlative phenomena such as depressed hard X-ray flux and anomalous low temperatures were studied to determine their utility for forecasting purposes. During the study period, March 2000 through December 2002, 107 hard X-ray flares were spectrally analyzed including 16 SEP-associated flares. Fourteen SEP flares were correctly identified, two SEPs were missed, and three false alarms (untrue predictions) were incurred.

  11. Geochemical investigation of dry- and wet-deposited dust during the same dust-storm event in Harbin, China: Constraint on provenance and implications for formation of aeolian loess

    Science.gov (United States)

    Xie, Yuanyun; Chi, Yunping

    2016-04-01

    A strong dust-storm event occurred in Harbin, China on May 11, 2011. The dry- and wet-deposited dust depositions in this dust-storm event, together with the surface sediments from the potential sources, were collected to study grain size distributions, carbonate content and carbon isotopic composition of carbonate, major element, trace element and rare earth elements (REE), and Sr-Nd isotopic compositions. The results indicate as follows. The dry-deposited dusts are characterized by bimodal grain-size distributions with a fine mode at 3.6 μm and a coarse mode at 28 μm whereas the wet-deposited dusts are indicative of unimodal grain-size modes with a fine mode at 6 μm. The dust-storm depositions are influenced to a certain extent by sedimentary sorting and are of a derivation from the recycled sediments. Based on identifying the immobility of element pairs before constraining sources of dust-storm deposits using geochemical elements, in conjunction with REE and especially Sr-Nd isotopic compositions, the primary and strengthening sources for the dust-storm event were detected, respectively. The Hunsandake Sandy Land as the primary source and the Horqin Sandy Land as the strengthening source were together responsible for the derivation of dust depositions during dust-storm event. The Hunsandake Sandy Land, however, contributes less dust to the dust-storm event in Harbin compared to the Horqin Sandy Land, and the Hulun Buir Sandy Land is undoubtedly excluded from being one of the sources for dust-storm depositions in Harbin. There are not notable differences in geochemical (especially Sr-Nd isotopic) compositions between dry- and wet-deposited dusts, indicating that the wet-deposited dust is of identical derivation to the dry-deposited dust. Based on our observations, it is of interest to suggest that fine and coarse particles in the CLP (Chinese Loess Plateau) loess possibly have the same sources.

  12. Properties of a local dust storm on Mars' Atlantis Chaos by means of radiative transfer modeling.

    Science.gov (United States)

    Oliva, Fabrizio; Altieri, Francesca; Geminale, Anna; Bellucci, Giancarlo; D'Aversa, Emiliano; Carrozzo, Giacomo; Sindoni, Giuseppe; Grassi, Davide

    2017-04-01

    In this study we present the analysis of the dust properties in a local storm imaged in the Atlantis Chaos region on Mars by the OMEGA spectrometer (Bibring et al., 2004) on March 2nd 2005 (ORB1441_5). By means of an inverse radiative transfer code we study the dust properties across the region and try to infer the connection be-tween the local storm dynamics and the orography. OMEGA is a visible and near-IR mapping spectrometer, operating in the spectral range 0.38-5.1 μm with three separate channels with different spectral resolution. The instrument's IFOV is 1.2 mrad. To analyze the storm properties we have used the inverse radiative transfer model MITRA (Oliva et al., 2016; Sindoni et al., 2013) to retrieve the effective radius reff, the optical depth at 880 nm τ880 and the top pressure tp of the dust layer. We used the Mars Climate Database (MCD, Forget et al., 1999) to obtain the atmospheric properties of the studied region to be used as input in our model. Moreover we used the optical constants from Wolff et al. (2009) to describe the dust composition. The properties from the surface have been obtained by ap-plying the SAS method (Geminale et al., 2015) to observations of the same region relatively clear from dust. All retrievals have been performed in the spectral range 500 ÷ 2500 nm. Here we describe the result from our analysis carried out on selected regions of the storm and characterized by a different optical depth of the dust. Aknowledgements: This study has been performed within the UPWARDS project and funded in the context of the European Union's Horizon 2020 Programme (H2020-Compet-08-2014), grant agreement UPWARDS-633127. References: Bibring, J-P. et al., 2004. OMEGA: Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité. Mars Express: the scientific payload, Ed. by Andrew Wilson, scientific coordination: Agustin Chicarro. ESA SP-1240, Noordwijk, Netherlands: ESA Publications Division, ISBN 92-9092-556-6, 2004, p. 37 - 49. Forget

  13. Investigating the Impact of Climate Change on Dust Storms Over Kuwait by the Middle of the Century Simulated by WRF Dynamical Downscaling

    Science.gov (United States)

    Alsarraf, Hussain

    The aim of this study is to examine the impact of climate change on future dust storms in Kuwait. Dust storms are more frequent in summertime in the Arabian Peninsula, and can be highly influential on the climate and the environment in the region. In this study, the influence of climate change in the Middle East and especially in Kuwait was investigated by high-resolution (48, 12, and 4 km grid spacing) dynamic downscaling using the WRF (Weather Research & Forecasting) model. The WRF dynamic downscaling was forced by reanalysis using the National Centers for Environment Prediction (NCEP) model for the years 1997, 2000, and 2008. The downscaling results were first validated by comparing NCEP model outputs with the observational data. The global climate change dynamic downscaling model was run using current WRF regional climate model (RCM) simulations (2006--2010) and WRF-RCM climate simulations of the future (2056--2060). They were used to compare results between the present and the middle of the century. In general, the dominant features from (NCEP) runs were consistent with each other, as well as with WRF-RCM results. The influence of climate change in the Middle East and Kuwait can be projected from the differences between the current and model future run. The average temperature showed a positive trend in the future, as in other studies. The temperature was predicted to increase by around 0.5-2.5 °C over the next 50 years. No significant change in mean sea level pressure patterns was projected. However, amongst other things, a change in the trend of the surface wind speeds was indicated during summertime. As a result, the increase in temperature and the decline in wind speed in the future indicate a reduction in dust storm days in Kuwait by the middle of the century.

  14. Orbit-spin coupling and the interannual variability of global-scale dust storm occurrence on Mars

    CERN Document Server

    Shirley, James H

    2016-01-01

    A new physical hypothesis predicts that a weak coupling of the orbital and rotational motions of extended bodies may give rise to a modulation of circulatory flows within their atmospheres. Driven cycles of intensification and relaxation of large-scale circulatory flows are predicted, with the phasing of these changes linked directly to the rate of change of the orbital angular momentum with respect to inertial frames. We test the hypothesis that global-scale dust storms (GDS) on Mars may occur when periods of circulatory intensification (associated with positive and negative extrema of the waveform) coincide with the southern summer dust storm season on Mars. The orbit-spin coupling hypothesis additionally predicts that the intervening transitional periods, which are characterized by the disappearance and subsequent sign change of this waveform, may be unfavorable for the occurrence of GDS, when they occur during the southern summer dust storm season. These hypotheses are confirmed through comparisons betwee...

  15. Influence of a dust storm on young cotton plants in the Hetian region of northwest China

    Science.gov (United States)

    Yuan, Chunqiong; Guo, Qingyu; Aniwiar, A.; Pan, Xiaoling

    2003-07-01

    Microclimate observation at 2 heights (10 and 50 centimeters) in young cotton plants fields with both normal windbreak and non-normal windbreak were carried out when a dust storm took place in May 1998. Meteorological indices on the intensity of damage to the young cotton plants were obtained. These results were shown that 5% young cotton plants were damaged slightly when average velocities at the 2 heights were 1.5m/s, 2.6m/s respectively; 10% young cotton plants were damaged when these velocities were 1.6m/s, 2.9m/s respectively; 20% young cotton plants were damaged when these velocities were 1.8m/s, 2.9m/s respectively; 35% young cotton plants were damaged seriously when these velocities were 2.3m/s, 3.4m/s respectively. Economical evaluation on these plants" damages caused by the dust storm was also conducted. The above indices were tested to be suitable in Hetian region. It is suggested that normal windbreak should be built in Hetian region in future.

  16. 中国北方一次强沙尘暴爆发的数值模拟研究%Numerical simulation of a severe dust-storm outbreak in northern China

    Institute of Scientific and Technical Information of China (English)

    孙辉; 晏利斌; 刘晓东

    2012-01-01

    Northern China is a region where dust storms occur frequently.Millions of tons of dust can be injected into atmosphere accompanying with the explosion of dust storms every year,especially in spring.Dust storms not only can cause huge damage to human lives and production activities,but also can influence the climate and environment due to physical and chemical effects of dust aerosols.However,available observations of the dust cycle are too limited to satisfy need of scientific research for in-depth understanding dust activities in northern China.So climate models incorporating with dust schemes including the emission,transport and deposition are often used to explore processes of dust activities.Meanwhile,it is important to improve or develop a model which can be used to forecast a dust storm.Although some scientists used different models to investigate dust storms in northern China,previous results were discrepant based on different model kernels.The regional climate model version 3(RegCM3),developed by the Abdus Salam International Centre for Theoretical Physics(ICTP),has been coupled with a desert dust module to investigate dust cycles and variations of dust aerosol optical depth(AOD).Although the RegCM3 has been widely used worldwide,there are few studies about its application in modeling dust storm events over northern China.Here the paper simulate a case of the severe dust storm of 9-11 April 2006 to evaluate the performance of this model.The paper mainly focus on two dust source regions of northern China.One is in the Taklimakan desert,the other is in the Gansu corridor.The simulated results show that the outbreak sites,synoptic situation and pattern of the corresponding AOD of this dust storm are successfully simulated,comparing with observation.This severe dust storm extensively exploded in the Tarim Basin and Turpan Basin at 6:00 a.m.on April 9 in 2006.24 hours later,the sandstorm began to outbreak in central Gansu and the western Inner

  17. Windblown Dust Deposition Forecasting and Spread of Contamination around Mine Tailings

    Directory of Open Access Journals (Sweden)

    Michael Stovern

    2016-01-01

    Full Text Available Wind erosion, transport and deposition of windblown dust from anthropogenic sources, such as mine tailings impoundments, can have significant effects on the surrounding environment. The lack of vegetation and the vertical protrusion of the mine tailings above the neighboring terrain make the tailings susceptible to wind erosion. Modeling the erosion, transport and deposition of particulate matter from mine tailings is a challenge for many reasons, including heterogeneity of the soil surface, vegetative canopy coverage, dynamic meteorological conditions and topographic influences. In this work, a previously developed Deposition Forecasting Model (DFM that is specifically designed to model the transport of particulate matter from mine tailings impoundments is verified using dust collection and topsoil measurements. The DFM is initialized using data from an operational Weather Research and Forecasting (WRF model. The forecast deposition patterns are compared to dust collected by inverted-disc samplers and determined through gravimetric, chemical composition and lead isotopic analysis. The DFM is capable of predicting dust deposition patterns from the tailings impoundment to the surrounding area. The methodology and approach employed in this work can be generalized to other contaminated sites from which dust transport to the local environment can be assessed as a potential route for human exposure.

  18. Characterisation of bio-aerosols during dust storm period in N-NW India

    Science.gov (United States)

    Yadav, Sudesh; Chauhan, M. S.; Sharma, Anupam

    Bio-investigations for pollen and spores were performed on dry free-fall dust and PM 10 aerosol samples, collected from three different locations separated by a distance of 600 km, situated in dust storm hit region of N-NW India. Presence of pollen of trees namely Prosopis ( Prosopis juliflora and Prosopis cinearia), Acacia, Syzygium, Pinus, Cedrus, Holoptelea and shrubs namely Ziziphus, Ricinus, Ephedra and members of Fabaceae, Oleaceae families was recorded but with varying proportions in the samples of different locations. Poaceae, Chenopodiaceae/Amaranthaceae, Caryophyllaceae, Brassicaceae and Cyperaceae (sedges) were some of the herb pollen identified in the samples. Among the fungal spores Nigrospora was seen in almost all samples. Nigrospora is a well known allergen and causes health problems. The concentration of trees and shrubs increases in the windward direction just as the climate changes from hot arid to semiarid. The higher frequency of grasses (Poaceae) or herbs could either be a result of the presence of these herbs in the sampling area and hence the higher production of pollen/spores or due to the resuspension from the exposed surface by the high-intensity winds. But we cannot ascertain the exact process at this stage. The overall similarity in the pollen and spore assemblage in our dust samples indicates a common connection or source(s) to the dust in this region. Presence of the pollen of the species of Himalayan origin in our entire samples strongly point towards a Himalayan connection, could be direct or indirect, to the bioaerosols and hence dust in N-NW India. In order to understand the transport path and processes involved therein, present study needs further extension with more number of samples and with reference to meteorological parameters.

  19. The radioactivity of seasonal dust storms in the Middle East: the May 2012 case study in Jordan.

    Science.gov (United States)

    Hamadneh, Hamed S; Ababneh, Zaid Q; Hamasha, Khadeejeh M; Ababneh, Anas M

    2015-02-01

    Dust storms in the Middle East are common during spring. Some of these storms are massive and carry a large amount of dust from faraway regions, which pose health and pollution risks. The huge dust storm event occurred in early May, 2012 was investigated for its radioactive content using gamma ray spectroscopy. Dust samples were collected from Northern Jordan and it was found that the storm carried a large amount of both artificial and natural radioactivity. The average activity concentration of fallout (137)Cs was 17.0 Bq/kg which is larger than that found in soil (2.3 Bq/kg), and this enrichment is attributed to particle size effects. (7)Be which is of atmospheric origin and has a relatively short half-life, was detected in dust with relatively large activity concentrations, as it would be expected, with an average of 2860 Bq/kg, but it was not detected in soil. Despite the large activity concentration of (7)Be, dose assessment showed that it does not contribute significantly to the effective dose through inhalation. The concentrations of the primodial nuclides (40)K, (232)Th and (238)U were 547, 30.0 and 49.3 Bq/kg, respectively. With the exception of (40)K, these were comparable to what was found in soil. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Short period forecasting of catchment-scale precipitation. Part II: a water-balance storm model for short-term rainfall and flood forecasting

    Directory of Open Access Journals (Sweden)

    V. A. Bell

    2000-01-01

    in Somerset. Keywords: rainfall forecasting, flood forecasting, weather radar, satellite, storm model

  1. Constraining storm-scale forecasts of deep convective initiation with surface weather observations

    Science.gov (United States)

    Madaus, Luke

    Successfully forecasting when and where individual convective storms will form remains an elusive goal for short-term numerical weather prediction. In this dissertation, the convective initiation (CI) challenge is considered as a problem of insufficiently resolved initial conditions and dense surface weather observations are explored as a possible solution. To better quantify convective-scale surface variability in numerical simulations of discrete convective initiation, idealized ensemble simulations of a variety of environments where CI occurs in response to boundary-layer processes are examined. Coherent features 1-2 hours prior to CI are found in all surface fields examined. While some features were broadly expected, such as positive temperature anomalies and convergent winds, negative temperature anomalies due to cloud shadowing are the largest surface anomaly seen prior to CI. Based on these simulations, several hypotheses about the required characteristics of a surface observing network to constrain CI forecasts are developed. Principally, these suggest that observation spacings of less than 4---5 km would be required, based on correlation length scales. Furthermore, it is anticipated that 2-m temperature and 10-m wind observations would likely be more relevant for effectively constraining variability than surface pressure or 2-m moisture observations based on the magnitudes of observed anomalies relative to observation error. These hypotheses are tested with a series of observing system simulation experiments (OSSEs) using a single CI-capable environment. The OSSE results largely confirm the hypotheses, and with 4-km and particularly 1-km surface observation spacing, skillful forecasts of CI are possible, but only within two hours of CI time. Several facets of convective-scale assimilation, including the need for properly-calibrated localization and problems from non-Gaussian ensemble estimates of the cloud field are discussed. Finally, the characteristics

  2. Impact of Two Intense Dust Storms on Aerosol Characteristics and Radiative Forcing over Patiala, Northwestern India

    Directory of Open Access Journals (Sweden)

    Deepti Sharma

    2012-01-01

    Full Text Available Impact of dust storms on the aerosol characteristics and radiative forcing over Patiala, northwestern India has been studied during April-June of 2010 using satellite observations and ground-based measurements. Six dust events (DE have been identified during the study period with average values of Aqua-MODIS AOD550 and Microtops-II AOD500 over Patiala as 1.00±0.51 and 0.84±0.41, respectively while Aura-OMI AI exhibits high values ranging from 2.01 to 6.74. The Ångström coefficients α380–870 and β range from 0.12 to 0.31 and 0.95 to 1.40, respectively. The measured spectral AODs, the OPAC-derived aerosol properties and the surface albedo obtained from MODIS were used as main inputs in SBDART model for the calculation of aerosol radiative forcing (ARF over Patiala. The ARF at surface (SRF and top of atmosphere (TOA ranges from ∼−50 to −100 Wm−2 and from ∼−10 to −25 Wm−2, respectively during the maximum of dust storms. The radiative forcing efficiency was found to be −66 Wm−2AOD−1 at SRF and −14 Wm−2AOD−1 at TOA. High values of ARF in the atmosphere (ATM, ranging between ∼+40 Wm−2 and +80.0 Wm−2 during the DE days, might have significant effect on the warming of the lower and middle atmosphere and, hence, on climate over northwestern India.

  3. Variability in the correlation between Asian dust storms and chlorophyll a concentration from the North to Equatorial Pacific.

    Science.gov (United States)

    Tan, Sai-Chun; Yao, Xiaohong; Gao, Hui-Wang; Shi, Guang-Yu; Yue, Xu

    2013-01-01

    A long-term record of Asian dust storms showed seven high-occurrence-frequency centers in China. The intrusion of Asian dust into the downwind seas, including the China seas, the Sea of Japan, the subarctic North Pacific, the North Pacific subtropical gyre, and the western and eastern Equatorial Pacific, has been shown to add nutrients to ocean ecosystems and enhance their biological activities. To explore the relationship between the transported dust from various sources to the six seas and oceanic biological activities with different nutrient conditions, the correlation between monthly chlorophyll a concentration in each sea and monthly dust storm occurrence frequencies reaching the sea during 1997-2007 was examined in this study. No correlations were observed between dust and chlorophyll a concentration in the atmospheric deposition is commonly believed to exert less impact on coastal seas. Significant correlations existed between dust sources and many sea areas, suggesting a link between dust and chlorophyll a concentration in those seas. However, the correlation coefficients were highly variable. In general, the correlation coefficients (0.54-0.63) for the Sea of Japan were highest, except for that between the subarctic Pacific and the Taklimakan Desert, where it was as high as 0.7. For the >50 m China seas and the North Pacific subtropical gyre, the correlation coefficients were in the range 0.32-0.57. The correlation coefficients for the western and eastern Equatorial Pacific were relatively low (dust sources, the transport pathways, the dust deposition, the nutrient conditions of oceans, and the probability of dust storms reaching the seas.

  4. Mineralogical characteristics of airborne particles collected in Beijing during a severe Asian dust storm period in spring 2002

    Institute of Scientific and Technical Information of China (English)

    SHAO LongYi; LI WeiJun; YANG ShuShen; SHI ZongBo; L(U) SenLin

    2007-01-01

    Asian dust storm (ADS) samples were collected on March 20, 2002 in Beijing, China. High-resolution field emission scanning electron microscopy with energy dispersive X-ray detector (FESEM-EDX) and X-ray diffraction (XRD) were used to study the morphology, chemical compositions, number-size distributions and mineralogical compositions of ADS particles. The mineral particles were major components in the ADS samples, accounting for 94% by number. The XRD analysis indicated that the dust particles were dominated by clay (40.3%), and quartz (19.5%), followed by plagioclase (8.4%), calcite (7.5%), K-feldspar (1.5%), hematite (0.9%), pyrite (0.9%), hornblende (0.4%) and gypsum (0.3%), with a certain amount of noncrystalline materials (20.3%). Clay minerals were mainly illite/smectite mixed layers (78%), followed by illite (9%), kaolinite (6%), and Chlorite (7%). In addition to these main minerals,FESEM-EDX also detected some trace minerals, such as dolomite, pyrite, thenardite, as well as heavy minerals represented by rutile, ilmenite and apatite. The mineralogical compositions of the 2002-03-20Asian dust storm and the Saharan dust plumes were similar but the clay mineralogy showed a great distinction, with the illite/smectite mixed layers being common in the Asian dust storm but illite being common in the Saharan dust plumes.

  5. Mineralogical characteristics of airborne particles collected in Beijing during a severe Asian dust storm period in spring 2002

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Asian dust storm (ADS) samples were collected on March 20,2002 in Beijing,China. High-resolution field emission scanning electron microscopy with energy dispersive X-ray detector (FESEM-EDX) and X-ray diffraction (XRD) were used to study the morphology,chemical compositions,number-size dis-tributions and mineralogical compositions of ADS particles. The mineral particles were major compo-nents in the ADS samples,accounting for 94% by number. The XRD analysis indicated that the dust particles were dominated by clay (40.3%),and quartz (19.5%),followed by plagioclase (8.4%),calcite (7.5%),K-feldspar (1.5%),hematite (0.9%),pyrite (0.9%),hornblende (0.4%) and gypsum (0.3%),with a certain amount of noncrystalline materials (20.3%). Clay minerals were mainly illite/smectite mixed lay-ers (78%),followed by illite (9%),kaolinite (6%),and chlorite (7%). In addition to these main minerals,FESEM-EDX also detected some trace minerals,such as dolomite,pyrite,thenardite,as well as heavy minerals represented by rutile,ilmenite and apatite. The mineralogical compositions of the 2002-03-20 Asian dust storm and the Saharan dust plumes were similar but the clay mineralogy showed a great distinction,with the illite/smectite mixed layers being common in the Asian dust storm but illite being common in the Saharan dust plumes.

  6. Visualizing uncertainties in a storm surge ensemble data assimilation and forecasting system

    KAUST Repository

    Hollt, Thomas

    2015-01-15

    We present a novel integrated visualization system that enables the interactive visual analysis of ensemble simulations and estimates of the sea surface height and other model variables that are used for storm surge prediction. Coastal inundation, caused by hurricanes and tropical storms, poses large risks for today\\'s societies. High-fidelity numerical models of water levels driven by hurricane-force winds are required to predict these events, posing a challenging computational problem, and even though computational models continue to improve, uncertainties in storm surge forecasts are inevitable. Today, this uncertainty is often exposed to the user by running the simulation many times with different parameters or inputs following a Monte-Carlo framework in which uncertainties are represented as stochastic quantities. This results in multidimensional, multivariate and multivalued data, so-called ensemble data. While the resulting datasets are very comprehensive, they are also huge in size and thus hard to visualize and interpret. In this paper, we tackle this problem by means of an interactive and integrated visual analysis system. By harnessing the power of modern graphics processing units for visualization as well as computation, our system allows the user to browse through the simulation ensembles in real time, view specific parameter settings or simulation models and move between different spatial and temporal regions without delay. In addition, our system provides advanced visualizations to highlight the uncertainty or show the complete distribution of the simulations at user-defined positions over the complete time series of the prediction. We highlight the benefits of our system by presenting its application in a real-world scenario using a simulation of Hurricane Ike.

  7. Multi-Spectral Satellite Imagery and Land Surface Modeling Supporting Dust Detection and Forecasting

    Science.gov (United States)

    Molthan, A.; Case, J.; Zavodsky, B.; Naeger, A. R.; LaFontaine, F.; Smith, M. R.

    2014-12-01

    Current and future multi-spectral satellite sensors provide numerous means and methods for identifying hazards associated with polluting aerosols and dust. For over a decade, the NASA Short-term Prediction Research and Transition (SPoRT) Center at Marshall Space Flight Center in Huntsville has focused on developing new applications from near real-time data sources in support of the operational weather forecasting community. The SPoRT Center achieves these goals by matching appropriate analysis tools, modeling outputs, and other products to forecast challenges, along with appropriate training and end-user feedback to ensure a successful transition. As a spinoff of these capabilities, the SPoRT Center has recently focused on developing collaborations to address challenges with the public health community, specifically focused on the identification of hazards associated with dust and pollution aerosols. Using multispectral satellite data from the SEVIRI instrument on the Meteosat series, the SPoRT team has leveraged EUMETSAT techniques for identifying dust through false color (RGB) composites, which have been used by the National Hurricane Center and other meteorological centers to identify, monitor, and predict the movement of dust aloft. Similar products have also been developed from the MODIS and VIIRS instruments onboard the Terra and Aqua, and Suomi-NPP satellites, respectively, and transitioned for operational forecasting use by offices within NOAA's National Weather Service. In addition, the SPoRT Center incorporates satellite-derived vegetation information and land surface modeling to create high-resolution analyses of soil moisture and other land surface conditions relevant to the lofting of wind-blown dust and identification of other, possible public-health vectors. Examples of land surface modeling and relevant predictions are shown in the context of operational decision making by forecast centers with potential future applications to public health arenas.

  8. Large Salt Dust Storms Follow a 30-Year Rainfall Cycle in the Mar Chiquita Lake (Cordoba, Argentina.

    Directory of Open Access Journals (Sweden)

    Enrique H Bucher

    Full Text Available Starting in 2006, a new source of intense salt dust storms developed in Mar Chiquita (Córdoba, Argentina, the largest saline lake in South America. Storms originate from vast mudflats left by a 30-year expansion-retreat cycle of the lake due to changes in the regional rainfall regime. The annual frequency of salt dust storms correlated with the size of the salt mudflats. Events were restricted to the coldest months, and reached up to 800 km from the source. Occurrence of dust storms was associated with specific surface colors and textures easily identifiable in satellite images. High-emission surfaces were characterized by the presence of sodium sulfate hydrous/anhydrous crystals (mirabilite and thenardite, and a superficial and variable water table, which may result in the periodic development of a characteristic "fluffy" surface derived from salt precipitation-dissolution processes. HYSPLIT model simulation estimates a deposition maximum near the sources (of about 2.5 kg/ha/yr, and a decreasing trend from the emission area outwards, except for the relative secondary maximum modeled over the mountain ranges in southern Bolivia and northern Argentina due to an orographic effect. The 2009 total deposition of salt dust generated in Mar Chiquita was estimated at 6.5 million tons.

  9. Large Salt Dust Storms Follow a 30-Year Rainfall Cycle in the Mar Chiquita Lake (Córdoba, Argentina).

    Science.gov (United States)

    Bucher, Enrique H; Stein, Ariel F

    2016-01-01

    Starting in 2006, a new source of intense salt dust storms developed in Mar Chiquita (Córdoba, Argentina), the largest saline lake in South America. Storms originate from vast mudflats left by a 30-year expansion-retreat cycle of the lake due to changes in the regional rainfall regime. The annual frequency of salt dust storms correlated with the size of the salt mudflats. Events were restricted to the coldest months, and reached up to 800 km from the source. Occurrence of dust storms was associated with specific surface colors and textures easily identifiable in satellite images. High-emission surfaces were characterized by the presence of sodium sulfate hydrous/anhydrous crystals (mirabilite and thenardite), and a superficial and variable water table, which may result in the periodic development of a characteristic "fluffy" surface derived from salt precipitation-dissolution processes. HYSPLIT model simulation estimates a deposition maximum near the sources (of about 2.5 kg/ha/yr), and a decreasing trend from the emission area outwards, except for the relative secondary maximum modeled over the mountain ranges in southern Bolivia and northern Argentina due to an orographic effect. The 2009 total deposition of salt dust generated in Mar Chiquita was estimated at 6.5 million tons.

  10. Satellite Monitoring of Long-Range Transport of Asian Dust Storms from Sources to Sinks

    Science.gov (United States)

    Hsu, N.; Tsay, S.; Jeong, M.; King, M.; Holben, B.

    2007-05-01

    Among the many components that contribute to air pollution, airborne mineral dust plays an important role due to its biogeochemical impact on the ecosystem and its radiative-forcing effect on the climate system. In East Asia, dust storms frequently accompany the cold and dry air masses that occur as part of spring-time cold front systems. China's capital, Beijing, and other large cities are on the primary pathway of these dust storm plumes, and their passage over such popu-lation centers causes flight delays, pushes grit through windows and doors, and forces people indoors. Furthermore, during the spring these anthropogenic and natural air pollutants, once generated over the source regions, can be transported out of the boundary layer into the free troposphere and can travel thousands of kilometers across the Pacific into the United States and beyond. In this paper, we will demonstrate the capability of a new satellite algorithm to retrieve aerosol optical thickness and single scattering albedo over bright-reflecting surfaces such as urban areas and deserts. Such retrievals have been dif-ficult to perform using previously available algorithms that use wavelengths from the mid-visible to the near IR because they have trouble separating the aerosol signal from the contribution due to the bright surface reflectance. The new algorithm, called Deep Blue, utilizes blue-wavelength measurements from instruments such as SeaWiFS and MODIS to infer the properties of aerosols, since the surface reflectance over land in the blue part of the spectrum is much lower than for longer wavelength channels. Deep Blue algorithm has recently been integrated into the MODIS processing stream and began to provide aerosol products over land as part of the opera-tional MYD04 products. In this talk, we will show the comparisons of the MODIS Deep Blue products with data from AERONET sunphotometers on a global ba-sis. The results indicate reasonable agreements between these two. These new

  11. Instantaneous influence of dust storms on the optical scattering property of the ocean: a case study in the Yellow Sea, China.

    Science.gov (United States)

    Chen, Shuguo; Zhang, Tinglu; Chen, Wenzhong; Shi, Jinhui; Hu, Lianbo; Song, Qingjun

    2016-12-12

    Asian dust storms originating from arid or semi-arid regions of China or her adjacent regions have important impact on the atmosphere and water composition, and ecological environment of the Eastern China Seas. This research used data collected in the middle of the South Yellow Sea, China, during a dust storm event from 23 April to 24 April 2006 to analyze the instantaneous influence of dust storms on optical scattering properties, which are closely related to particle characteristics. The analysis results showed that the dust storm had a remarkable influence on the optical scattering property in the upper mixed layer of water, and dust particles drily deposited from the dust storm with an aerosol optical depth of nearly 2.5 into the water could induce a 0.14 m-1 change in the water optical scattering coefficient at 532 nm at the depth of 4 m. The duration of the instantaneous influence of the dust storm on the water optical scattering properties was short, and this influence disappeared rapidly within approximately 3 hours after the end of the dust storm.

  12. Development of a dust deposition forecast model for a mine tailings impoundment

    Science.gov (United States)

    Stovern, Michael

    Wind erosion, transport and deposition of particulate matter can have significant impacts on the environment. It is observed that about 40% of the global land area and 30% of the earth's population lives in semiarid environments which are especially susceptible to wind erosion and airborne transport of contaminants. With the increased desertification caused by land use changes, anthropogenic activities and projected climate change impacts windblown dust will likely become more significant. An important anthropogenic source of windblown dust in this region is associated with mining operations including tailings impoundments. Tailings are especially susceptible to erosion due to their fine grain composition, lack of vegetative coverage and high height compared to the surrounding topography. This study is focused on emissions, dispersion and deposition of windblown dust from the Iron King mine tailings in Dewey-Humboldt, Arizona, a Superfund site. The tailings impoundment is heavily contaminated with lead and arsenic and is located directly adjacent to the town of Dewey-Humboldt. The study includes in situ field measurements, computational fluid dynamic modeling and the development of a windblown dust deposition forecasting model that predicts deposition patterns of dust originating from the tailings impoundment. Two instrumented eddy flux towers were setup on the tailings impoundment to monitor the aeolian and meteorological conditions. The in situ observations were used in conjunction with a computational fluid dynamic (CFD) model to simulate the transport of windblown dust from the mine tailings to the surrounding region. The CFD model simulations include gaseous plume dispersion to simulate the transport of the fine aerosols, while individual particle transport was used to track the trajectories of larger particles and to monitor their deposition locations. The CFD simulations were used to estimate deposition of tailings dust and identify topographic mechanisms

  13. Observing a Severe Dust Storm Event over China using Multiple Satellite Data

    Science.gov (United States)

    Xu, Hui; Xue, Yong; Guang, Jie; Mei, Linlu

    2013-04-01

    A severe dust storm (SDS) event occurred from 19 to 21 March 2010 in China, originated in western China and Mongolia and propagated into eastern/southern China, affecting human's life in a large area. As reported by National Meteorological Center of CMA (China Meteorological Administration), 16 provinces (cities) of China were hit by the dust storm (Han et al., 2012). Satellites can provide global measurements of desert dust and have particular importance in remote areas where there is a lack of in situ measurements (Carboni et al., 2012). To observe a dust, it is necessary to estimate the spatial and temporal distributions of dust aerosols. An important metric in the characterisation of aerosol distribution is the aerosol optical depth (AOD) (Adhikary et al., 2008). Satellite aerosol retrievals have improved considerably in the last decade, and numerous satellite sensors and algorithms have been generated. Reliable retrievals of dust aerosol over land were made using POLarization and Directionality of the Earth's Reflectance instrument-POLDER (Deuze et al., 2001), Moderate Resolution Imaging Spectroradiometer-MODIS (Kaufman et al., 1997; Hsu et al., 2004), Multiangle Imaging Spectroradiometer-MISR (Martonchik et al., 1998), and Cloud-aerosol Lidar and infrared pathfinder satellite observations (CALIPSO). However, intercomparison exercises (Myhre et al., 2005) have revealed that discrepancies between satellite measurements are particularly large during events of heavy aerosol loading. The reason is that different AOD retrieval algorithms make use of different instrument characteristics to obtain retrievals over bright surfaces. For MISR, POLDER and MODIS instrument, the multi-angle approaches, the polarization measurements and single-view approaches were used to retrieval AOD respectively. Combining of multi-sensor AOD data can potentially create a more consistent, reliable and complete picture of the space-time evolution of dust storms (Ehlers, 1991). In order to

  14. NM-MT network and space dangerous phenomena, 2. Examples of cosmic ray using for forecasting of major geomagnetic storms

    Science.gov (United States)

    Belov, A.; Dorman, L.; Eroshenko, E.; Iucci, N.; Parisi, M.; Pustil Nik, L.; Sternlieb, A.; Villoresi, G.; Yanke, V.; Zukerman, I.

    We present developing of methods (e.g., Dorman et al., 1995, 1999) for forecasting on the basis of neutron monitor hourly on-line data (as well as on-line muon telescopes hourly data from different directions) geomagnetic storms of scales G5 (3- hour index of geomagnetic activity Kp=9), G4 (Kp=8) and G3 (Kp=7) (according to NOAA Space Weather Scales). These geomagnetic storms are dangerous for people technology and health (influence on power systems, on spacecraft operations, on HF radio-communications and others). We show that for especially dangerous geomagnetic storms can be used global-spectrographic method if on-line will be available 35-40 NM and muon telescopes. In this case for each hour can be determined CR anisotropy vector, and the specifically behavior of this vector before SC of geomagnetic storms G5, G4 or G3 (according to NOAA Space Weather Scales) can be used as important factor for forecast. The second factor what can be used for SC forecast is specifically behavior of CR density (CR intensity) for about 30-15 hours before SC (caused mainly by galactic CR particles acceleration during interaction with shock wave moved from the Sun). The third factor is effect of cosmic ray pre-decreasing, caused by magnetic connection of the Earth with the region behind the shock wave. We demonstrate developing methods on several examples of major geomagnetic storms. This research is partly supported by the INTAS grant 00-0810. REFERENCES: Dorman L.I., et al. "Cosmic-ray forecasting features for big Forbush-decreases". Nuclear Physics B, 49A, 136-144 (1995). L.I.Dorman, et al, "Cosmic ray Forbush-decrease as indicators of space dangerous phenomenon and possible use of cosmic ray data for their prediction", Proc. of 26-th Intern. Cosmic Ray Conference, Salt Lake City, 6, 476-479 (1999).

  15. Cosmic Ray Monitoring and Space Dangerous Phenomena, 2. Methods of Cosmic Ray Using For Forecasting of Major Geomagnetic Storms

    Science.gov (United States)

    Belov, A. V.; Dorman, L. I.; Eroshenko, E. A.; Iucci, N.; Mavromichalaki, H.; Pustil'Nik, L. A.; Sternlieb, A.; Villoresi, G.; Yanke, V. G.; Zukerman, I. G.

    We present developing of methods (e.g., Dorman et al., 1995, 1999) for forecasting on the basis of neutron monitor hourly on-line data (as well as on-line muon tele- scopes hourly data from different directions) geomagnetic storms of scales G5 (3- hour index of geomagnetic activity Kp=9), G4 (Kp=8) and G3 (Kp=7) (according to NOAA Space Weather Scales). These geomagnetic storms are dangerous for peo- ple technology and health (influence on power systems, on spacecraft operations, on HF radio-communications and others). We show that for especially dangerous geo- magnetic storms can be used global-spectrographic method if on-line will be avail- able 35-40 NM and muon telescopes. In this case for each hour can be determined CR anisotropy vector, and the specifically behavior of this vector before SC of ge- omagnetic storms G5, G4 or G3 (according to NOAA Space Weather Scales) can be used as important factor for forecast. The second factor what can be used for SC forecast is specifically behavior of CR density (CR intensity) for about 30-15 hours before SC (caused mainly by galactic CR particles acceleration during interaction with shock wave moved from the Sun). The third factor is effect of cosmic ray pre- decreasing, caused by magnetic connection of the Earth with the region behind the shock wave. We demonstrate developing methods on several examples of major ge- omagnetic storms. REFERENCES: Dorman L.I., et al. "Cosmic-ray forecasting fea- tures for big Forbush-decreases". Nuclear Physics B, Vol. 49A, pp. 136-144. (1995). L.I.Dorman, et al, "Cosmic ray Forbush-decrease as indicators of space dangerous phenomenon and possible use of cosmic ray data for their prediction", Proc. of 26-th Intern. Cosmic Ray Conference, Salt Lake City, Vol. 6, p. 476-479, (1999).

  16. Asian dust storm observed at a rural mountain site in southern China: chemical evolution and heterogeneous photochemistry

    Directory of Open Access Journals (Sweden)

    W. Nie

    2012-12-01

    Full Text Available Heterogeneous processes on dust particles are important for understanding the chemistry and radiative balance of the atmosphere. This paper investigates an intense Asian dust storm episode observed at Mount Heng (1269 m a.s.l. in southern China on 24–26 April 2009. A set of aerosol and trace gas data collected during the study was analyzed to investigate their chemical evolution and heterogeneous photochemistry as the dust traveled to southern China. Results show that the mineral dust arriving at Mt. Heng experienced significant modifications during transport, with large enrichments in secondary species (sulfate, nitrate, and ammonium compared with the dust composition collected at an upwind mountain top site (Mount Hua. A photochemical age "clock" (−Log10(NOx/NOy was employed to quantify the atmospheric processing time. The result indicates an obvious increase in the abundance of secondary water-soluble ions in dust particles with the air mass atmospheric processing time. Based on the observations, a 4-stage evolution process is proposed for carbonate-containing Asian dust, starting from fresh dust to particles coated with hydrophilic and acidic materials. Daytime-enhanced nitrite formation on the dust particles was also observed, which indicates the recent laboratory result of the TiO2 photocatalysis of NO2 as a potential source of nitrite and nitrous acid.

  17. Asian dust storm observed at a rural mountain site in Southern China: chemical evolution and heterogeneous photochemistry

    Directory of Open Access Journals (Sweden)

    W. Nie

    2012-08-01

    Full Text Available Heterogeneous processes on dust particles are important for understanding the chemistry and radiative balance of the atmosphere. This paper investigates an intense Asian dust storm episode observed at Mount Heng (1250 m a.s.l. in Southern China on 24–26 April 2009. A set of aerosol and trace gas data collected during the study was analyzed to investigate their chemical evolution and heterogeneous photochemistry as the dust traveled to Southern China. Results show that the mineral dust arriving at Mt. Heng experienced significant modifications during transport, with large enrichments in secondary species (sulfate, nitrate, and ammonium compared with the dust composition collected at an upwind mountain top site (Mount Hua. A photochemical age "clock" (−log10(NOx/NOy was employed to quantify the atmospheric processing time. The result indicates an obvious increase in the abundance of secondary water-soluble ions in dust particles with the air mass' photochemical age. Based on the observations, a 4-stage evolution process is proposed for carbonate-rich Asian dust, starting from fresh dust to particles coated with hydrophilic and acidic materials. Daytime-enhanced nitrite formation on the dust particles was also observed, which indicates the recent laboratory result of the TiO2 photocatalysis of NO2 as a potential source of nitrite and nitrous acid.

  18. Possible influence of Arctic Oscillation on dust storm frequency in North China%北极涛动对华北沙尘暴频次的影响

    Institute of Scientific and Technical Information of China (English)

    毛睿; 龚道溢; 包景东; 范一大

    2011-01-01

    This study has investigated the influence of Arctic Oscillation (AO) on dust storm frequency in North China in spring seasons during 1961-2007. There is a significant linkage between dust storm frequency and AO; a negative (positive) AO phase is related to an increased (decreased) dust storm frequency in North China. This relationship is closely related to changes in the cold air activity in Mongolia. The cold air activity exerts large impacts on the dust storm frequency; the frequency of cold air activity over Mongolia not only positively correlates with the dust storm frequency in North China, but also shows a long-term decreasing trend that is an important reason for the long-term decreasing of dust storm frequency in North China. The AO has large influence on the frequency of cold air activity over Mongolia; a negative (positive) AO phase is highly related to an increased (decreased) frequency of cold air activity over Mongolia, which results in an increased (decreased) dust storm frequency in North China.

  19. The Dust Storm Index (DSI): A method for monitoring broadscale wind erosion using meteorological records

    Science.gov (United States)

    O'Loingsigh, T.; McTainsh, G. H.; Tews, E. K.; Strong, C. L.; Leys, J. F.; Shinkfield, P.; Tapper, N. J.

    2014-03-01

    Wind erosion of soils is a natural process that has shaped the semi-arid and arid landscapes for millennia. This paper describes the Dust Storm Index (DSI); a methodology for monitoring wind erosion using Australian Bureau of Meteorology (ABM) meteorological observational data since the mid-1960s (long-term), at continental scale. While the 46 year length of the DSI record is its greatest strength from a wind erosion monitoring perspective, there are a number of technical challenges to its use because when the World Meteorological Organisation (WMO) recording protocols were established the use of the data for wind erosion monitoring was never intended. Data recording and storage protocols are examined, including the effects of changes to the definition of how observers should interpret and record dust events. A method is described for selecting the 180 long-term ABM stations used in this study and the limitations of variable observation frequencies between stations are in part resolved. The rationale behind the DSI equation is explained and the examples of temporal and spatial data visualisation products presented include; a long term national wind erosion record (1965-2011), continental DSI maps, and maps of the erosion event types that are factored into the DSI equation. The DSI is tested against dust concentration data and found to provide an accurate representation of wind erosion activity. As the ABM observational records used here were collected according to WMO protocols, the DSI methodology could be used in all countries with WMO-compatible meteorological observation and recording systems.

  20. The compositions, sources, and size distribution of the dust storm from China in spring of 2000 and its impact on the global environment

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The average mass concentration of the aerosols in Beijing during the dust storm in the spring of 2000 was ~6000 mg·m-3, ~30 times as high as that in the non-dust storm days. The enrichment factors of the pollution elements As, Sb and Se were higher than those in the non-dust storm days. This indicated that As, Sb and Se resulted from the pollution sources of those areas, through which the dust storm passed during their long-range transport, in addition to the local pollution sources in Beijing. The enrichment factors of the Pb, Zn, Cd and Cu were much less than those in the non-dust storm days, suggesting that the local pollution sources in Beijing area contributed to them mostly. The enrichment factors of elements Al, Fe, Sc, Mn, Na, Ni, Cr, V and Co were close to 1, showing that these elements originated from crust. The concentration of S in the dust storm was ~10 mg·m-3, 4 times as high as that in non-dust storm. S in the aerosols resulted from the adsorption of gaseous SO2 and the conse-quent transformation on it. The aerosols of the dust storm contained 16.1% and 76.9% of fine particles with the sizes less than 2.1 and 9.0 mm, respectively, while it had a large number of coarse particles. It was noted that a considerable portion of Fe(Ⅱ) was detected from the dust storm. Fe(Ⅱ) could easily dissolve in seawater to be nutrient for phyto-plankton and would lead to the increase of the emission of dimethylsulfide (DMS) from the ocean. The feedbacks of Fe coupled with S in atmosphere might be the important mechanism that would affect the primary productivity in Pacific and/or the global climate change.

  1. An early South Asian dust storm during March 2012 and its impacts on Indian Himalayan foothills: a case study.

    Science.gov (United States)

    Srivastava, A K; Soni, V K; Singh, Sachchidanand; Kanawade, V P; Singh, N; Tiwari, S; Attri, S D

    2014-09-15

    The impacts of an early South Asian dust storm that originated over the western part of the Middle East and engulfed northwest parts of India during the third week of March 2012 have been studied at four different stations covering India and Pakistan. The impacts of this dust storm on aerosol optical properties were studied in detail at Delhi, Jodhpur, Lahore and Karachi. The impact could also be traced up to central Himalayan foothills at Manora Peak. During dust events, the aerosol optical depth (AOD) at 500 nm reached a peak value of 0.96, 1.02, 2.17 and 0.49 with a corresponding drop in Ångström exponent (AE for 440-870 nm) to 0.01, -0.02, 0.00 and 0.12 at Delhi, Jodhpur, Lahore and Karachi, respectively. The single scattering albedo (SSA) at 675 nm was relatively lower at Delhi (0.87) and Jodhpur (0.86), with absorption Ångström exponent (AAE) less than 1.0, but a large value of SSA was observed at Lahore (0.98) and Karachi (0.93), with AAE value greater than 1.0 during the event. The study of radiative impact of dust aerosols revealed a significant cooling at the surface and warming in the atmosphere (with corresponding large heating rate) at all the stations during dust event. The effect of this dust storm was also seen at Manora Peak in central Himalayas which showed an enhancement of ~28% in the AOD at 500 nm. The transport of dust during such events can have severe climatic implications over the affected plains and the Himalayas.

  2. The impact of atmospheric dry deposition associated microbes on the southeastern Mediterranean Sea surface water following an intense dust storm

    Directory of Open Access Journals (Sweden)

    Eyal Rahav

    2016-07-01

    Full Text Available This study explores the potential impacts of microbes deposited into the surface seawater of the southeastern Mediterranean Sea (SEMS along with atmospheric particles on marine autotrophic and heterotrophic production. We compared in situ changes in autotrophic and heterotrophic microbial abundance and production rates before and during an intense dust storm event in early September 2015. Additionally, we measured the activity of microbes associated with atmospheric dry deposition (also referred to as airborne microbes in sterile SEMS water using the same particles collected during the dust storm. A high diversity of prokaryotes and a low diversity of autotrophic eukaryotic algae were delivered to surface SEMS waters by the storm. Autotrophic airborne microbial abundance and activity were low, contributing ~1% of natural abundance in SEMS water and accounting for 1-4% to primary production. Airborne heterotrophic bacteria comprised 30-50% of the cells and accounted for 13-42% of bacterial production. Our results demonstrate that atmospheric dry deposition may supply not only chemical constitutes but also microbes that can affect ambient microbial populations and their activity in the surface ocean. Airborne microbes may play a greater role in ocean biogeochemistry in the future in light of the expected enhancement of dust storm durations and frequencies due to climate change and desertification processes.

  3. The Dust at Altitude Recovery Technology (DART) System was Developed to Recover Plant, Human, and Animal Pathogens in Asian and African Dust Storms over North America

    Science.gov (United States)

    Schuerger, A. C.; Tench, B.; Nehr, A.; Emmons, T.; Valbuena, F.; Palaia, J.; Sugars, C.

    2014-12-01

    Dust emanates year-round from Africa and Asia and impacts air quality in North America. Asian dust plumes deliver up to 64 million tonnes of dust over the NW of the USA, and African dust storms deliver over 50 million tonnes of dust over Florida each year. Several recent studies have demonstrated that human and plant pathogens from Asian [1] African [2] aerosols can be transported to N. America in naturally occurring dust storms. What is unknown is whether these 'presumptive pathogens' impact human, plant, or animal health in the USA. In order to initiate a long-term monitoring program of pathogens in Asian and African dust plumes, we have developed a dust collection system called DART (Dust at Altitude Recovery Technology) (figure). The DART dust sampler can be mounted on a F104 Starfighter jet (figure) and a T6 Texan propeller driven airplane (not shown), and was test flown over FL in Dec. 2013 on the F104 and on the T6 in the summer of 2014. The DART system utilizes a high-volume pump to pass air through 6 separate filtration units where both aerosols and microbial cells are captured. The filtration systems exhibit flow rates from 25-142 L/min depending on the pore size and brand of filters used. Flow rates are directly correlated to increased air speed, and are inversely correlated to increased altitude. Filtration units can be turned on and off individually as required for specific science flight objectives. The DART dust sampler has performed nominally up to 7600 m, 0.92 Mach, and 3.5 +G's. During initial test flights in Dec. 2013, 5 of 8 genera of fungi recovered from the lower atmosphere over FL contained plant pathogens including species in the genera: Acremonium, Aspergillus, Cladosporium, Curvularia, and Fusarium. Numbers of recovered fungi, but not bacteria, increased significantly when 5 or 10 µm filters were used in the DART system compared to filter pore sizes ≤ 1.2 µm. Future sampling programs for both Asian and African dust events will be

  4. Multiplatform analysis of the radiative effects and heating rates for an intense dust storm on 21 June 2007

    Science.gov (United States)

    Naeger, Aaron R.; Christopher, Sundar A.; Johnson, Ben T.

    2013-08-01

    Dust radiative effects and atmospheric heating rates are investigated for a Saharan dust storm on 21 June 2007 using a combination of multiple satellite data sets and ground and aircraft observations as input into a delta-four stream radiative transfer model (RTM). This combines the strengths of the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations and CloudSat satellites and in situ aircraft data to characterize the vertical structure of the dust layers (5 km in height with optical depths between 1.5 and 2.0) and underlying low-level water clouds. These observations were used, along with Aerosol Robotic Network retrievals of aerosol optical properties, as input to the RTM to assess the surface, atmosphere, and top of atmosphere (TOA) shortwave aerosol radiative effects (SWAREs). Our results show that the dust TOA SWARE per unit aerosol optical depth was -56 W m-2 in cloud-free conditions over ocean and +74 W m-2 where the dust overlay low-level clouds, and show heating rates greater than 10 K/d. Additional case studies also confirm the results of the 21 June case. This study shows the importance of identifying clouds beneath dust as they can have a significant impact on the radiative effects of dust, and hence assessments of the role of dust aerosol on the energy budget and climate.

  5. Study of Electrical Activity in Martian Dust Storms with the Deep Space Network antennas

    Science.gov (United States)

    Martinez, S.; Kuiper, T. B. H.; Majid, W. A.; Garcia-Miro, C.; Tamppari, L. K.; Renno, N. O.; Ruf, C.; Trinh, J. T.

    2012-09-01

    Evidence for non-thermal emission produced by electrostatic discharges in a deep Martian dust storm has been reported by Ruf et al. 2009 [1]. Such discharges had been detected with an innovative kurtosis detector installed in a 34m radio telescope of the Deep Space Network (DSN) in June of 2006. The kurtosis (the fourth central moment of the signal normalized by the square of the second central moment) is extremely sensitive to the presence of non-thermal radiation, but is insensitive to variations in the intensity of the thermal radiation and instrument gain. The non-thermal radiation was detected while a 35 Km deep Martian dust storm was within the field of view of the radio telescope and presented signatures of modulation by the Martian Schumann Resonance. Encouraged by this discovery, several attempts have been made within the DSN to confirm the detection using the R&D antenna (DSS-13) and other antennas in the Madrid and Goldstone complexes, but using a very limited receiver, in terms of recorded data rates, the Very Long Baseline Interferometry (VLBI) Science Receiver (VSR). We are planning to initiate an extensive monitoring of Mars emission in a noninterfering basis while our antennas are tracking various Mars probes, using the Wideband Very Long Baseline Interferometry (VLBI) Science Receiver (WVSR). The WVSR is a very flexible open-loop digital backend that is used for radio science and spacecraft navigation support in the DSN. This instrument allows us to sample a larger bandwidth than with previously used detectors. The processing to look for the kurtosis signature will be performed in software, limited only by the computer capacity. Additionally there are plans to develop an even more powerful custom-built detector based in CASPER technology and Graphic Processing Units for enhance computational power. This contribution will describe how we plan to select the target Mars tracking passes from the DSN schedule. An automated process will generate

  6. Aerosols optical and physical characteristics and direct radiative forcing during a "Shamal" dust storm, a case study

    Directory of Open Access Journals (Sweden)

    T. M. Saeed

    2013-09-01

    Full Text Available Dust aerosols are analyzed for their optical and physical properties during an episode of dust storm that hit Kuwait on 26 March 2003 when "Iraqi Freedom" military operation was in full swing. The intensity of the dust storm was such that it left a thick suspension of dust throughout the following day, 27 March, resulting in a considerable cooling effect at the surface on both days. Ground-based measurements of aerosol optical thickness reached 3.617 and 4.17 on 26–27 March respectively while Ångstrom coefficient, α870/440, dropped to −0.0234 and −0.0318. Particulate matter concentration of diameter 10 μm or less, PM10, peaked at 4800 μg m−3 during dust storm hours of 26 March. Moderate resolution imaging spectrometer (MODIS retrieved optical and physical characteristics that exhibited extreme values as well. The synoptic of the dust storm is presented and source regions are identified using total ozone mapping spectrometer (TOMS aerosol index retrieved images. The vertical profile of the dust layer was simulated using SKIRON atmospheric model. Instantaneous net direct radiative forcing is calculated at top of atmosphere (TOA and surface level. The thick dust layer of 26 March resulted in cooling the TOA by −60 Wm−2 and surface level by −175 Wm−2 for a surface albedo of 0.35. Slightly higher values were obtained for 27 March due to the increase in aerosol optical thickness. The large reduction in the radiative flux at the surface level had caused a drop in surface temperature by approximately 6 °C below its average value. Radiative heating/cooling rates in the shortwave and longwave bands were also examined. Shortwave heating rate reached a maximum value of 2 °K day−1 between 3 and 5 km, dropped to 1.5 °K day−1 at 6 km and diminished at 8 km. Longwave radiation initially heated the lower atmosphere by a maximum value of 0.2 °K day−1 at surface level, declined sharply at increasing altitude and diminished at 4 km

  7. A Hybrid Approach by Integrating Brain Storm Optimization Algorithm with Grey Neural Network for Stock Index Forecasting

    Directory of Open Access Journals (Sweden)

    Yanqiu Sun

    2014-01-01

    Full Text Available Stock index forecasting is an important tool for both the investors and the government organizations. However, due to the inherent large volatility, high noise, and nonlinearity of the stock index, stock index forecasting has been a challenging task for a long time. This paper aims to develop a novel hybrid stock index forecasting model named BSO-GNN based on the brain storm optimization (BSO approach and the grey neural network (GNN model by taking full advantage of the grey model in dealing with data with small samples and the neural network in handling nonlinear fitting problems. Moreover, the new developed BSO-GNN, which initializes the parameters in grey neural network with the BSO algorithm, has great capability in overcoming the deficiencies of the traditional GNN model with randomly initialized parameters through solving the local optimum and low forecasting accuracy problems. The performance of the proposed BSO-GNN model is evaluated under the normalization and nonnormalization preprocessing situations. Experimental results from the Shanghai Stock Exchange (SSE Composite Index, the Shenzhen Composite Index, and the HuShen 300 Index opening price forecasting show that the proposed BSO-GNN model is effective and robust in the stock index forecasting and superior to the individual GNN model.

  8. Short-Term Forecasting of Urban Storm Water Runoff in Real-Time using Extrapolated Radar Rainfall Data

    DEFF Research Database (Denmark)

    Thorndahl, Søren Liedtke; Rasmussen, Michael R.

    2013-01-01

    Model based short-term forecasting of urban storm water runoff can be applied in realtime control of drainage systems in order to optimize system capacity during rain and minimize combined sewer overflows, improve wastewater treatment or activate alarms if local flooding is impending. A novel...... online system, which forecasts flows and water levels in real-time with inputs from extrapolated radar rainfall data, has been developed. The fully distributed urban drainage model includes auto-calibration using online in-sewer measurements which is seen to improve forecast skills significantly....... The radar rainfall extrapolation (nowcast) limits the lead time of the system to two hours. In this paper, the model set-up is tested on a small urban catchment for a period of 1.5 years. The 50 largest events are presented....

  9. Transient teleconnection event at the onset of a planet-encircling dust storm on Mars

    Directory of Open Access Journals (Sweden)

    O. Martínez-Alvarado

    2009-09-01

    Full Text Available We use proper orthogonal decomposition (POD to study a transient teleconnection event at the onset of the 2001 planet-encircling dust storm on Mars, in terms of empirical orthogonal functions (EOFs. There are several differences between this and previous studies of atmospheric events using EOFs. First, instead of using a single variable such as surface pressure or geopotential height on a given pressure surface, we use a dataset describing the evolution in time of global and fully three-dimensional atmospheric fields such as horizontal velocity and temperature. These fields are produced by assimilating Thermal Emission Spectrometer observations from NASA's Mars Global Surveyor spacecraft into a Mars general circulation model. We use total atmospheric energy (TE as a physically meaningful quantity which weights the state variables. Second, instead of adopting the EOFs to define teleconnection patterns as planetary-scale correlations that explain a large portion of long time-scale variability, we use EOFs to understand transient processes due to localised heating perturbations that have implications for the atmospheric circulation over distant regions. The localised perturbation is given by anomalous heating due to the enhanced presence of dust around the northern edge of the Hellas Planitia basin on Mars. We show that the localised disturbance is seemingly restricted to a small number (a few tens of EOFs. These can be classified as low-order, transitional, or high-order EOFs according to the TE amount they explain throughout the event. Despite the global character of the EOFs, they show the capability of accounting for the localised effects of the perturbation via the presence of specific centres of action. We finally discuss possible applications for the study of terrestrial phenomena with similar characteristics.

  10. Hospital admissions in Iran for cardiovascular and respiratory diseases attributed to the Middle Eastern Dust storms.

    Science.gov (United States)

    Khaniabadi, Yuef Omidi; Fanelli, Roberto; De Marco, Alessandra; Daryanoosh, Seyed Mohammad; Kloog, Itai; Hopke, Philip K; Conti, Gea Oliveri; Ferrante, Margherita; Mohammadi, Mohammad Javad; Babaei, Ali Akbar; Basiri, Hassan; Goudarzi, Gholamreza

    2017-07-01

    The main objective of this study was to assess the possible effects of airborne particulate matter less than 10 μm in diameter (PM10) from the Middle Eastern Dust (MED) events on human health in Khorramabad (Iran) in terms of estimated hospital admissions (morbidity) for cardiovascular diseases (HACD) and for respiratory diseases (HARD) during the period of 2015 to 2016. The AirQ program developed by the World Health Organization (WHO) was used to estimate the potential health impacts to daily PM10 exposures. The numbers of excess cases for cardiovascular/respiratory morbidity were 20/51, 72/185, and 20/53 on normal, dusty, and MED event days, respectively. The highest number of hospital admissions was estimated for PM10 concentrations in the range of 40 to 49 μg/m(3), i.e, lower than the daily (50 μg/m(3)) limit value established by WHO. The results also showed that 4.7% (95% CI 3.2-6.7%) and 4.2% (95% CI 2.6-5.8%) of HARD and HACD, respectively, were attributed to PM10 concentrations above 10 μg/m(3). The study demonstrates a significant impact of air pollution on people, which is manifested primarily as respiratory and cardiovascular problems. To reduce these effects, several immediate actions should be taken by the local authorities to control the impacts of dust storms on residents' health, e.g., developing a green beltway along the Iran-Iraq border and management of water such as irrigation of dry areas that would be effective as mitigation strategies.

  11. PM10 concentration levels at an urban and background site in Cyprus: the impact of urban sources and dust storms.

    Science.gov (United States)

    Achilleos, Souzana; Evans, John S; Yiallouros, Panayiotis K; Kleanthous, Savvas; Schwartz, Joel; Koutrakis, Petros

    2014-12-01

    Air quality in Cyprus is influenced by both local and transported pollution, including desert dust storms. We examined PM10 concentration data collected in Nicosia (urban representative) from April 1, 1993, through December 11, 2008, and in Ayia Marina (rural background representative) from January 1, 1999, through December 31, 2008. Measurements were conducted using a Tapered Element Oscillating Micro-balance (TEOM). PM10 concentrations, meteorological records, and satellite data were used to identify dust storm days. We investigated long-term trends using a Generalized Additive Model (GAM) after controlling for day of week, month, temperature, wind speed, and relative humidity. In Nicosia, annual PM10 concentrations ranged from 50.4 to 63.8 μg/m3 and exceeded the EU annual standard limit enacted in 2005 of 40 μg/m3 every year A large, statistically significant impact of urban sources (defined as the difference between urban and background levels) was seen in Nicosia over the period 2000-2008, and was highest during traffic hours, weekdays, cold months, and low wind conditions. Our estimate of the mean (standard error) contribution of urban sources to the daily ambient PM10 was 24.0 (0.4) μg/m3. The study of yearly trends showed that PM10 levels in Nicosia decreased from 59.4 μg/m3 in 1993 to 49.0 μg/m3 in 2008, probably in part as a result of traffic emission control policies in Cyprus. In Ayia Marina, annual concentrations ranged from 27.3 to 35.6 μg/m3, and no obvious time trends were observed. The levels measured at the Cyprus background site are comparable to background concentrations reported in other Eastern Mediterranean countries. Average daily PM10 concentrations during desert dust storms were around 100 μg/m3 since 2000 and much higher in earlier years. Despite the large impact ofdust storms and their increasing frequency over time, dust storms were responsible for a small fraction of the exceedances of the daily PM10 limit. Implications: This

  12. Extreme dust storm over the eastern Mediterranean in September 2015: satellite, lidar, and surface observations in the Cyprus region

    Science.gov (United States)

    Mamouri, Rodanthi-Elisavet; Ansmann, Albert; Nisantzi, Argyro; Solomos, Stavros; Kallos, George; Hadjimitsis, Diofantos G.

    2016-11-01

    A record-breaking dust storm originating from desert regions in northern Syria and Iraq occurred over the eastern Mediterranean in September 2015. In this contribution of a series of two articles (part 1, observations; part 2, atmospheric modeling), we provide a comprehensive overview of the aerosol conditions during this extreme dust outbreak in the Cyprus region. These observations are based on satellite observations (MODIS, moderate resolution imaging spectroradiometer) of aerosol optical thickness (AOT) and Ångström exponent, surface particle mass (PM10) concentrations measured at four sites in Cyprus, visibility observations at three airports in southern Cyprus and corresponding conversion products (particle extinction coefficient, dust mass concentrations), EARLINET (European Aerosol Research Lidar Network) lidar observations of dust vertical layering over Limassol, particle optical properties (backscatter, extinction, lidar ratio, linear depolarization ratio), and derived profiles of dust mass concentrations. Maximum 550 nm AOT exceeded values of 5.0, according to MODIS, and the mass loads were correspondingly > 10 g m-2 over Larnaca and Limassol during the passage of an extremely dense dust front on 8 September 2015. Hourly mean PM10 values were close to 8000 µg m-3 and the observed meteorological optical range (visibility) was reduced to 300-750 m at Larnaca and Limassol. The visibility observations suggest peak values of the near-surface total suspended particle (TSP) extinction coefficients of 6000 Mm-1 and thus TSP mass concentrations of 10 000 µg m-3. The Raman polarization lidar observations mainly indicated a double layer structure of the dust plumes (reaching to about 4 km height), pointing to at least two different dust source regions. Dust particle extinction coefficients (532 nm) already exceeded 1000 Mm-1 and the mass concentrations reached 2000 µg m-3 in the elevated dust layers on 7 September, more than 12 h before the peak dust front on

  13. 塔克拉玛干沙漠沙尘演变及气候因素分析%Dust storms evolution in Taklimakan Desert and its correlation with climatic parameters

    Institute of Scientific and Technical Information of China (English)

    肖风劲; 周才平; 廖要明

    2008-01-01

    Based on the sand dust storms data and climatic data in 12 meteorological stationsa round sand dust storm originating areas of the Taklimakan Desert, we analyzed the trends of the number of dust storm days from 1960 to 2005 as well as their correlations with temperature, precipitation, wind speed and the number of days with mean wind speed 5 m/s. The results show that the frequency of dust storm events in the Taklimakan region decreased with the elapse of time. Except Ruoqiang and Minfeng, in the other 10 meteorological stations, the frequency of dust storm events reduces, and in 4 meteorological stations of Kuqa, Korla,Kalpin and Hotan, the frequency of dust storm events distinctly decreases. The temperature has an increasing trend, while the average wind speed and the number of days with mean wind speed 5 m/s have decreasing trends. The correlation analysis between the number of days of dust storms and climatic parameters demonstrates that wind speed and the number of days with mean wind speed 5 m/s have strong positive correlation with the number of days of dust storms, with the correlations coefficients being 0.743 and 0.720 (p<0.01),respectively, which indicates that strong wind is the direct factor resulting in sand dust storms.Whereas precipitation has significant negative correlation with the number of days of dust storms (p<0.01), and the prior annual precipitation has also negative correlation, which indicates that the prior precipitation restrains the occurrence of sand dust storms, but this restraining action is weaker than the same year's precipitation. Temperature has negative correlation with the number of dust storm days, with a correlations coefficient of -0.433 (p<0.01),which means that temperature change also has impacts on the occurrence of dust storm events in the Taklimakan region.

  14. Integration of RGB "Dust" Imagery to Operations at the Albuqueque Forecast Office

    Science.gov (United States)

    Fuell, Kevin; Guyer, Brian

    2014-01-01

    The NASA/Short-term Prediction, Research, and Transition (SPoRT) Program has been providing unique Red-Green-Blue (RGB) composite imagery to its operational partners since 2005. In the early years of activity these RGB products were related to a True Color RGB, showing what one's own eyes would see if looking down at earth from space, as well as a Snow-Cloud RGB (i.e. False Color), separating clouds from snow on the ground. More recently SPoRT has used the EUMETSAT Best Practices standards for RGB composites to transition a wide array of imagery for multiple uses. A "Dust" RGB product has had particular use at the Albuquerque, New Mexico WFO. Several cases have occurred where users were able to isolate dust plume locations for mesoscale and microscale events during day and night time conditions. In addition the "Dust" RGB can be used for more than just detection of dust as it is sensitive to the changes in density due to atmospheric moisture content. Hence low-level dry boundaries can often be discriminated. This type of imagery is a large change from the single channel imagery typically used by operational forecast staff and hence, can be a challenge to interpret. This presentation aims to discuss the integration of such new imagery into operational use as well as the benefits assessed by the Albuquerque WFO over several documented events.

  15. Integration of RGB "Dust" Imagery to Operations at the Albuquerque Forecast Office

    Science.gov (United States)

    Fuell, Kevin; Guyer, Brian

    2014-01-01

    The NASA/Short-term Prediction, Research, and Transition (SPoRT) Program has been providing unique Red-Green-Blue (RGB) composite imagery to its operational partners since 2005. In the early years of activity these RGB products were related to a True Color RGB, showing what one's own eyes would see if looking down at earth from space, as well as a Snow-Cloud RGB (i.e. False Color), separating clouds from snow on the ground. More recently SPoRT has used the EUMETSAT Best Practices standards for RGB composites to transition a wide array of imagery for multiple uses. A "Dust" RGB product has had particular use at the Albuquerque, New Mexico WFO. Several cases have occurred where users were able to isolate dust plume locations for mesoscale and microscale events during day and night time conditions. In addition the "Dust" RGB can be used for more than just detection of dust as it is sensitive to the changes in density due to atmospheric moisture content. Hence low-level dry boundaries can often be discriminated. This type of imagery is a large change from the single channel imagery typically used by operational forecast staff and hence, can be a challenge to interpret. This presentation aims to discuss the integration of such new imagery into operational use as well as the benefits assessed by the Albuquerque WFO over several documented events.

  16. Dust storm in Asia continent and its bio-environmental effects in the North Pacific: A case study of the strongest dust event in April, 2001 in central Asia

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Testing the effects of iron fertilization in booming metabolism of microbes in North Pacific Ocean has become an important hot topic in current global climate change study. The first supportive evidence with natural iron inputs to ocean was obtained by Bishop and his colleagues at the PAPA region in North Pacific Ocean. They found a rapid increase of marine phytoplankton over North Pacific Ocean after a strong dust storm in April 2001. We demonstrate that the dust deposition flux during this dust storm period decreases exponentially with increasing distance from the dust source regions along the dust transport pathway, through integration of synoptic dynamics, changes of TOMS-AI (aerosol index) and surface PM10 values along the dust pathway and changes of particulate organic carbon and chlorophyll in surface oceans. This strong dust storm may result in deposition of about 3.1-5.8 μg/m3 eolian iron into the PAPA region in North Pacific Ocean, thus causing a rapid increase of marine phytoplankton productivity observed by Bishop and his colleagues. This work supplies more direct and detailed evidence, from continental dust process, to support the iron hypothesis with natural iron inputs to the surface oceans through dust storms.

  17. Wind-Enhanced Interaction of Radiation and Dust (WEIRD) and the Growth and Maintenance of Local Dust Storms on Mars

    CERN Document Server

    Rafkin, Scot C Randell

    2011-01-01

    A radiative-dynamic positive feedback mechanism (Wind Enhanced Interaction of Radiation and Dust: WEIRD) for localized Mars dust disturbances was previously found to operate in highly idealized numerical experiments. Numerical simulations are used to test for the presence and quantitative effect of the radiative-dynamic WEIRD feedback mechanism under more realistic conditions. Comparisons between cases where lifted dust is radiatively active and radiatively passive elucidate the importance of the dust radiative forcing on the thermodynamic and kinematic structure of the atmosphere. The WEIRD feedback mechanism does operate under realistic conditions, although it can be masked and diminished by a variety of other forcing mechanisms. Globally increased dust loading is found to accelerate the local winds while simultaneously diminishing the impact of local physiographical forcing. Local enhancements of dust produce a thermal and dynamical response that resembles many of the essential features seen in the idealiz...

  18. Remote sensing and modelling analysis of the extreme dust storm hitting the Middle East and eastern Mediterranean in September 2015

    Science.gov (United States)

    Solomos, Stavros; Ansmann, Albert; Mamouri, Rodanthi-Elisavet; Binietoglou, Ioannis; Patlakas, Platon; Marinou, Eleni; Amiridis, Vassilis

    2017-03-01

    The extreme dust storm that affected the Middle East and the eastern Mediterranean in September 2015 resulted in record-breaking dust loads over Cyprus with aerosol optical depth exceeding 5.0 at 550 nm. We analyse this event using profiles from the European Aerosol Research Lidar Network (EARLINET) and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), geostationary observations from the Meteosat Second Generation (MSG) Spinning Enhanced Visible and Infrared Imager (SEVIRI), and high-resolution simulations from the Regional Atmospheric Modeling System (RAMS). The analysis of modelling and remote sensing data reveals the main mechanisms that resulted in the generation and persistence of the dust cloud over the Middle East and Cyprus. A combination of meteorological and surface processes is found, including (a) the development of a thermal low in the area of Syria that results in unstable atmospheric conditions and dust mobilization in this area, (b) the convective activity over northern Iraq that triggers the formation of westward-moving haboobs that merge with the previously elevated dust layer, and (c) the changes in land use due to war in the areas of northern Iraq and Syria that enhance dust erodibility.

  19. Chemical composition of PM10 and its in vitro toxicological impacts on lung cells during the Middle Eastern Dust (MED) storms in Ahvaz, Iran.

    Science.gov (United States)

    Naimabadi, Abolfazl; Ghadiri, Ata; Idani, Esmaeil; Babaei, Ali Akbar; Alavi, Nadali; Shirmardi, Mohammad; Khodadadi, Ali; Marzouni, Mohammad Bagherian; Ankali, Kambiz Ahmadi; Rouhizadeh, Ahmad; Goudarzi, Gholamreza

    2016-04-01

    Reports on the effects of PM10 from dust storm on lung cells are limited. The main purpose of this study was to investigate the chemical composition and in vitro toxicological impacts of PM10 suspensions, its water-soluble fraction, and the solvent-extractable organics extracted from Middle Eastern Dust storms on the human lung epithelial cell (A549). Samples of dust storms and normal days (PM10 Iran. The chemical composition and cytotoxicity were analyzed by ICP- OES and Lactase Dehydrogenase (LDH) reduction assay, respectively. The results showed that PM10 suspensions, their water-soluble fraction and solvent-extractable organics from both dust storm and normal days caused a decrease in the cell viability and an increase in LDH in supernatant in a dose-response manner. Although samples of normal days showed higher cytotoxicity than those of dust storm at the highest treated dosage, T Test showed no significant difference in cytotoxicity between normal days and dust event days (P value > 0.05). These results led to the conclusions that dust storm PM10 as well as normal day PM10 could lead to cytotoxicity, and the organic compounds (PAHs) and the insoluble particle-core might be the main contributors to cytotoxicity. Our results showed that cytotoxicity and the risk of PM10 to human lung may be more severe during dust storm than normal days due to inhalation of a higher mass concentration of airborne particles. Further research on PM dangerous fractions and the most responsible components to make cytotoxicity in exposed cells is recommended.

  20. Ambient particulate matter and carbon monoxide at an urban site of India: Influence of anthropogenic emissions and dust storms.

    Science.gov (United States)

    Yadav, Ravi; Sahu, L K; Beig, G; Tripathi, Nidhi; Jaaffrey, S N A

    2017-06-01

    Continuous measurements of PM2.5, PM10 and CO were conducted at an urban site of Udaipur in India from April 2011 to March 2012. The annual mean concentrations of PM2.5, PM10 and CO were 42 ± 17 μg m(-3), 114 ± 31 μg m(-3) and 343 ± 136 ppbv, respectively. Concentrations of both particulate and CO showed high values during winter/pre-monsoon (dry) period and lowest in the monsoon season (wet). Local anthropogenic emission and long-range transport from open biomass burning sources along with favourable synoptic meteorology led to elevated levels of pollutants in the dry season. However, higher values of PM10/PM2.5 ratio during pre-monsoon season were caused by the episodes of dust storm. In the monsoon season, flow of cleaner air, rainfall and negligible emissions from biomass burning resulted in the lowest levels of pollutants. The concentrations of PM2.5, PM10 and CO showed highest values during morning and evening rush hours, while lowest in the afternoon hours. In winter season, reductions of PM2.5, CO and PM10 during weekends were highest of 15%, 13% and 9%, respectively. In each season, the highest PM2.5/PM10 ratio coincided with the highest concentrations of pollutants (CO and NOX) indicating predominant emissions from anthropogenic sources. Exceptionally high concentrations of PM10 during the episode of dust storm were due to transport from the Arabian Peninsula and Thar Desert. Up to ∼32% enhancements of PM10 were observed during strong dust storms. Relatively low levels of O3 and NOx during the storm periods indicate the role of heterogeneous removal. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Elemental and carbonaceous characterization of TSP and PM10 during Middle Eastern dust (MED) storms in Ahvaz, Southwestern Iran.

    Science.gov (United States)

    Shahsavani, Abbas; Yarahmadi, Maryam; Hadei, Mostafa; Sowlat, Mohammad Hossein; Naddafi, Kazem

    2017-08-21

    Middle Eastern dust (MED) storms carry large amounts of dust particles to the Southern and Western cities of Iran. This study aimed to characterize the elemental and carbonaceous composition of total suspended particles (TSP) and PM10 in Ahvaz, Iran. TSP and PM10 samples were collected using two separate high-volume air samplers. The sampling program was performed according to EPA guidelines and resulted in 72 samples. Twenty-eight elements and two carbonaceous components in TSP and PM10 were measured. Over the entire study period, the mean concentration (SD) of TSP and PM10 was 1548.72 μg/m(3) (1965.11 μg/m(3)) and 1152.35 μg/m(3) (1510.34 μg/m(3)), respectively. The order of concentrations of major species were Si > Al > Ca > OC > Na > B > Zn > Mn > K > Mg and Si > Ca > Al > Na > OC > B > K > Mn > Cu > Mg for TSP and PM10, respectively. Almost all elements (except for Cd, Cr, and Cu) and carbonaceous components (except for organic carbon) had dust days/non-dust days (DD/NDD) ratios higher than 1, implying that all components are somehow affected by dust storms. Crustal elements constituted the major portion of particles for both TSP and PM10 in both DDs and NDDs. The enrichment factor of elements such as Ca, Fe, K, Mg, Na, and Ti was near unity. Species such as Al, Ca, Fe, K, Na, Si, and EC had high correlation coefficients in both TSP and PM10 (except for EC). In conclusion, Ahvaz is exposed to high concentrations of TSP and PM10 during the MED period. Immediate actions must be planned to decrease the high concentrations of particulate matter in Ahvaz's ambient air.

  2. Potential impacts of northeastern Eurasian snow cover on generation of dust storms in northwestern China during spring

    Science.gov (United States)

    Lee, Yun Gon; Ho, Chang-Hoi; Kim, Jhoon; Kim, Jinwon

    2013-08-01

    The effects of the northeastern Eurasian snow cover on the frequency of spring dust storms in northwestern China have been examined for the period 1979-2007. Averaged over all 43 stations in northwestern China, a statistically significant relationship has been found between dust-storm frequency (DSF) and Eurasian snow-water equivalent (SWE) during spring: mean DSF of 7.4 and 3.3 days for years of high- and low SWE, respectively. Further analyses reveal that positive SWE anomalies enhance the meridional gradients of the lower tropospheric temperatures and geopotential heights, thereby strengthening westerly jets and zonal wind shear over northwestern China and western Inner Mongolia of China, the regions of major dust sources. The anomalous atmospheric circulation corresponding to the Eurasian SWE anomalies either reinforces or weakens atmospheric baroclinicity and cyclogenesis, according to the sign of the anomaly, to affect the spring DSF. This study suggests that Eurasian SWE anomalies can be an influential factor of spring DSF in northwestern China and western Inner Mongolia of China.

  3. The influence of different underlying surface on sand-dust storm in northern China%华北地区不同下垫面对沙尘暴的影响

    Institute of Scientific and Technical Information of China (English)

    宋阳; 全占军; 刘连友

    2005-01-01

    In this paper, a quantitative research on the relationship between different underlying surface and sand-dust storm has been made by using 40 years meteorological data of five different types of underlying surface in northern China, which include farmland, grassland, sandland, gobi and salt crust.These metrological data comprise sand-dust storm days and strong wind days. By analyzing, we can find that there are certain correlations between the days of sand-dust storm and strong wind for different underlying surface, which has great influence on sand-dust storm. But there are pronounced differences in different types of underlying surface. The sand-dust storm days of grassland, gobi and salt crust, with smaller interannual variation are obviously less than strong wind days. On the other hand, the sand-dust storm days of farmland and sandland increase evidently, even in many years, are much more than strong wind days. The differences are mainly induced by the influencing mechanism of different underlying surface on sand-dust storm. Grassland, gobi and salt crust with stable underlying surface are not prone to sand-dust storm under strong wind condition. Whereas, the underlying surface of farmland and sandland is unstable, that is easy to induce sand-dust storm under strong wind condition.

  4. Asian Dust Storm Events of 2001 and Associated Pollution Observed in New England by the AIRMAP Monitoring Network

    Science.gov (United States)

    Debell, L. J.; Vozzella, M. E.; Talbot, R. W.; Dibb, J. E.

    2002-12-01

    The Atmospheric Investigation, Regional Modeling, Analysis and Prediction (AIRMAP) program is operating 4 monitoring sites in New Hampshire, located at Fort Constitution (FC)(43.07oN, 70.71oW, 5m elevation), Thompson Farm (TF) (43.11oN, 70.95oW, 21m elevation), Castle Springs (CS) (43.75oN,71.35oW, 406m elevation) and Mount Washington (MW)(44.267oN, 71.30oW, 1909m elevation). Three chemically distinct, statistically extreme, regional scale dust aerosol events were observed at all four AIRMAP monitoring stations in NH between 4/18/01 and 5/13/01 (UTC). All three events, at all four sites, had days where the 24 hr bulk aerosol samples had Ca2+ concentrations that exceeded at least the 95th percentile of the site-specific, multi-year datasets. NO3- and SO42- were also enhanced above typical levels, ranging from above the 75th to above the 99th percentile. During all three events, mixing ratios of the gas phase pollutants O3 and CO were compared to mixing ratios on either side of the events. During event 1,enhancements above background levels were approximately 130 ppbv for CO and 30 ppbv for O3, very similar to the CO values in apparent Asian dust plumes sampled over Colorado at 6-7 km by aircraft measurements (http://www.cmdl.noaa.gov/info/asiandust.html); enhancements during events 2 and 3 were similar to event 1. The maximum elemental carbon value ever observed at TF, 0.97 μg/m3, occurred during the peak day of event 1. Elemental carbon was not substantially elevated during event 2 and no data were collected during event 3. Elemental ratios, determined by PIXE, on filters from events 1 and 3 were compared pairwise to each other and to published samples attributed to Asian dust storms. The AIRMAP samples collected on the same date at different sites showed good statistical agreement whereas samples collected at the same site on different dates show only moderate correlation. Of 17 published samples of Asian dust storm aerosol, collected well outside of the major

  5. New Asia Dust Storm Detection Method Based on the Thermal Infrared Spectral Signature

    Directory of Open Access Journals (Sweden)

    Hui Xu

    2014-12-01

    Full Text Available As hyperspectral instruments can provide the detailed spectral information, a new spectral similarity method for detecting and differentiating dust from non-dust scenes using the Atmospheric Infrared Sounder (AIRS observations has been developed. The detection is based on a pre-defined Dust Spectral Similarity Index (DSSI, which was calculated from the accumulated brightness temperature differences between selected 16 AIRS observation channels, in the thermal infrared region of 800–1250 cm−1. It has been demonstrated that DSSI can effectively separate the dust from non-dust by elevating dust signals. For underlying surface covered with dust, the DSSI tends to show values close to 1.0. However, the values of DSSI for clear sky surfaces or clouds (ice and water are basically lower than those of dust, as their spectrums have significant differences with dust. To evaluate this new simple DSSI dust detection algorithm, several Asia dust events observed in northern China were analyzed, and the results agree favorably with those from the Moderate resolution Imaging Spectro radiometer (MODIS and Cloud Aerosol LiDAR with Orthogonal Polarization (CALIOP observations.

  6. Short-term effect of dust storms on the risk of mortality due to respiratory, cardiovascular and all-causes in Kuwait

    Science.gov (United States)

    Al-Taiar, Abdullah; Thalib, Lukman

    2014-01-01

    This study aimed to investigate the impact of dust storms on short-term mortality in Kuwait. We analyzed respiratory and cardiovascular mortality as well as all-cause mortality in relation to dust storm events over a 5-year study period, using data obtained through a population-based retrospective ecological time series study. Dust storm days were identified when the national daily average of PM10 exceeded 200 μg/m3. Generalized additive models with Poisson link were used to estimate the relative risk (RR) of age-stratified daily mortality associated with dust events, after adjusting for potential confounders including weather variables and long-term trends. There was no significant association between dust storm events and same-day respiratory mortality (RR = 0.96; 95 %CI 0.88-1.04), cardiovascular mortality (RR = 0.98; 95 %CI 0.96-1.012) or all-cause mortality (RR = 0.99; 95 %CI 0.97-1.00). Overall our findings suggest that local dust, that most likely originates from crustal materials, has little impact on short-term respiratory, cardiovascular or all-cause mortality.

  7. Synergistic Use of Remote Sensing and Modeling for Tracing Dust Storms in the Mediterranean

    Directory of Open Access Journals (Sweden)

    D. G. Kaskaoutis

    2012-01-01

    Full Text Available This study focuses on the detection of the dust source region and monitoring of the transport of the dust plume from its primary outflow to final deposition. The application area is the Sahara desert and the eastern Mediterranean, where two dust events occurred during the period 4–6 February 2009, an unusual event for a winter period. The Aqua-MODIS and OMI observations clearly define the spatial distribution of the dust plumes, while the CALIPSO observations of total attenuated backscatter (TAB at 532 nm, depolarization ratio (DR, and attenuated color ratio (1064/532 nm on 5 February 2009 provide a clear view and vertical structure of the dust-laden layer. The dust source region is defined to be near the Chad-Niger-Libyan borders, using satellite observations and model (DREAM output. This dust plume is vertically extended up to 2.5 km and is observed as a mass plume of dust from surface level to that altitude, where the vertical variation of TAB (0.002 to 0.2 and DR (0.2–0.5 implies dust-laden layer with non-spherical particles. CALIPSO profiles show that after the dust plume reached at its highest level, the dust particles start to be deposited over the Mediterranean and the initial dust plume was strongly attenuated, while features of dust were limited below about 1–1.5 km for latitudes northern of ~36° (Greek territory.

  8. Towards a system for sea state forecasts in the Bulgarian Black Sea coastal zone: the case of the storm of 07-08 february 2012

    OpenAIRE

    Galabov, Vasko; Kortcheva, Anna; Dimitrova, Marieta

    2012-01-01

    The paper describes the existing operational sea state forecast system of NIMH- BAS for sea state in the Black Sea and our current progress on the implementation of an additional component for the forecasts of wind waves in the Bulgarian coastal zone. Wind Waves and especially the extreme ones, occurring during severe storms are a major hazard for the coastal zone, causing significant damages to the infrastructure, threat for the human lives and also causing significant damages to the protect...

  9. Adverse effects of inhaled sand dust particles on the respiratory organs of sheep and goats exposed to severe sand storms in Mongolia.

    Science.gov (United States)

    Kobayashi, Yoshimi; Shimada, Akinori; Nemoto, Mai; Morita, Takehito; Adilbish, Altanchimeg; Bayasgalan, Mungun-Ochir

    2014-01-01

    Sand storms in Mongolia have increased in frequency and scale, resulting in increased exposure of the inhabitants of Asian countries, including Japan and Korea, to Asian sand dust (ASD), which results in adverse effects on the respiratory system. However, there is no information on the health risks of severe sand storms in domestic animals in Mongolia. The aim of the study was to investigate the effects of sand dust particles on the respiratory organs, including the lungs and tracheobronchial lymph nodes, of sheep and goats exposed to severe sand storms in Mongolia. Seven adult sheep and 4 adult goats that had been exposed to sand storms and 3 sheep with no history of exposure were included in this study. Lung tissues and tracheobronchial lymph nodes were subjected to histopathological and immunohistochemical examination. The mineralogical contents of the lungs and lymph nodes were determined using inductively coupled plasma atomic emission spectroscopy. Fibrosis and granulomatous lesions comprising macrophages containing fine sand dust particles were observed exclusively in the lungs of sheep and goats exposed to sand storms. The activity of macrophages was also demonstrated by the presence of IL-6, TNF, and lysozyme. In addition, silicon, which is the major element of ASD (kosa aerosol), was detected exclusively in the lung tissues of the exposed animals. Our findings suggest that exposure to sand dust particles may affect the respiratory systems of domestic animals during their relatively short life span.

  10. L-band microwave remote sensing and land data assimilation improve the representation of pre-storm soil moisture conditions for hydrologic forecasting

    Science.gov (United States)

    Recent advances in remote sensing and land data assimilation purport to improve the quality of antecedent soil moisture information available for operational hydrologic forecasting. We objectively validate this claim by calculating the strength of the relationship between storm-scale runoff ratio (i...

  11. Probabilistic forecasting of the disturbance storm time index: An autoregressive Gaussian process approach

    NARCIS (Netherlands)

    M.H. Chandorkar (Mandar); E. Camporeale (Enrico); S.P. Wing (Simon)

    2017-01-01

    textabstractWe present a methodology for generating probabilistic predictions for the Disturbance Storm Time(Dst) geomagnetic activity index. We focus on the One Step Ahead prediction task and use the OMNI hourly resolution data to build our models. Our proposed methodology is based on the technique

  12. 我国北方沙尘天气的气候成因分析%Climatic controls of dust storm events in northern China

    Institute of Scientific and Technical Information of China (English)

    吴占华; 任国玉; 徐卫丽; 刘瑞兰

    2011-01-01

    本研究的范围在30°N以北地区,站点340个.通过采用区域平均及相关分析的方法,将中国北方沙尘(扬沙+沙尘暴)事件的年、季特征及其关系较为密切的地面气象要素包括降水、温度、风(风速、大风日数、风速≥5 m/s的日数)、湿度、蒸发量作了详细、综合的相关、对比分析.结果表明:春季多降水对沙尘天气的发生可以起到明显的抑制作用;前冬至次年春季的气温突变容易诱发沙尘天气的发生;在温度偏高、湿度较大、风力偏弱、蒸发量不大的年份,少沙尘天气;风要素是影响沙尘天气最为直接相关的因子.%The sand-dust weather is a typical disastrous weather, which can be divided into three categories;sandstorm , blowing sand and floating dust. Sand and dust weather usually occurs in the semi - arid, arid and desert area. The formation of dust storms to be three basic conditions; First, high winds. The other is the ground bare sand material. Three are unstable air. Days with sand dust are attributed to the background of large - scale circulations. In addition to this,it is related to climatic factors. In northern China is the worlds four major storms District (Central Asia, North America, Africa and Australia) ,sandstorm zone in Central Asia as part of modem dust storms, which are one of high incidence areas. In this paper, the author analyzed climatological variation of dust storms from 340 observation stations selected in Northern China from 1961 to 2003. By using correlation analysis and regional mean method,, the relationship between the variability features on seasonal and inter - annual scales of tendency of days with dust storms and the influencial factors such as precipition, air temperature, wind, relative humidity, evaporation and so on is analyzed and discussed in detail. The results are observed,that in spring the declining of days with dust storms is obviously related to increasing precipition, dust storm

  13. A quantitative comparison of precipitation forecasts between the storm-scale numerical weather prediction model and auto-nowcast system in Jiangsu, China

    Science.gov (United States)

    Wang, Gaili; Yang, Ji; Wang, Dan; Liu, Liping

    2016-11-01

    Extrapolation techniques and storm-scale Numerical Weather Prediction (NWP) models are two primary approaches for short-term precipitation forecasts. The primary objective of this study is to verify precipitation forecasts and compare the performances of two nowcasting schemes: a Beijing Auto-Nowcast system (BJ-ANC) based on extrapolation techniques and a storm-scale NWP model called the Advanced Regional Prediction System (ARPS). The verification and comparison takes into account six heavy precipitation events that occurred in the summer of 2014 and 2015 in Jiangsu, China. The forecast performances of the two schemes were evaluated for the next 6 h at 1-h intervals using gridpoint-based measures of critical success index, bias, index of agreement, root mean square error, and using an object-based verification method called Structure-Amplitude-Location (SAL) score. Regarding gridpoint-based measures, BJ-ANC outperforms ARPS at first, but then the forecast accuracy decreases rapidly with lead time and performs worse than ARPS after 4-5 h of the initial forecast. Regarding the object-based verification method, most forecasts produced by BJ-ANC focus on the center of the diagram at the 1-h lead time and indicate high-quality forecasts. As the lead time increases, BJ-ANC overestimates precipitation amount and produces widespread precipitation, especially at a 6-h lead time. The ARPS model overestimates precipitation at all lead times, particularly at first.

  14. Multi-spacecraft testing of time-dependent interplanetary MHD models for operational forecasting of geomagnetic storms

    Science.gov (United States)

    Dryer, M.; Smith, Z. K.

    1989-01-01

    An MHD 2-1/2D, time-dependent model is used, together with observations of six solar flares during February 3-7, 1986, to demonstrate global, large-scale, compound disturbances in the solar wind over a wide range of heliolongitudes. This scenario is one that is likely to occur many times during the cruise, possibly even encounter, phases of the Multi-Comet Mission. It is suggested that a model such as this one should be tested with multi-spacecraft data (such as the MCM and earth-based probes) with several goals in view: (1) utility of the model for operational real-time forecasting of geomagnetic storms, and (2) scientific interpretation of certain forms of cometary activities and their possible association with solar-generated activity.

  15. Cosmic Ray Monitoring and Space Dangerous Phenomena, 1. Search of Features In Cosmic Rays What Can Be Used For Forecasting of Major Geomagnetic Storms

    Science.gov (United States)

    Dorman, L. I.; Pustil'Nik, L. A.; Sternlieb, A.; Zukerman, I. G.

    According to NOAA Space Weather Scales, geomagnetic storms of scales G5 (3- hour index of geomagnetic activity Kp=9), G4 (Kp=8) and G3 (Kp=7) are dangerous for people technology and health (influence on power systems, on spacecraft oper- ations, on HF radio-communications and others). To prevent these serious damages will be very important to forecast dangerous geomagnetic storms. In many papers it was shown that in principle for this forecasting can be used data on CR intensity and CR anisotropy changing before SC of major geomagnetic storms accompanied by sufficient Forbush-decreases (e.g., Dorman et al., 1995, 1999). In this paper we con- sider over 100 major geomagnetic storms and for each case we analyze hourly data of many NM for 8 days with SC in the 4-st day of 8-days period (that before SC we have at least 3 full days). We determine what part of major geomagnetic storms is accompanied CR intensity and CR anisotropy changing before SC, and what part of major geomagnetic storms does not show any features what can be used for forecast- ing. We estimate also how these parts depend from the index of geomagnetic activ- ity Kp. REFERENCES: Dorman L.I., et al. "Cosmic-ray forecasting features for big Forbush-decreases". Nuclear Physics B, Vol. 49A, pp. 136-144. (1995). L.I.Dorman, et al, "Cosmic ray Forbush-decrease as indicators of space dangerous phenomenon and possible use of cosmic ray data for their prediction", Proc. of 26-th Intern. Cos- mic Ray Conference, Salt Lake City, Vol. 6, p. 476-479, (1999).

  16. Health risk assessment of exposure to the Middle-Eastern Dust storms in the Iranian megacity of Kermanshah.

    Science.gov (United States)

    Goudarzi, G; Daryanoosh, S M; Godini, H; Hopke, P K; Sicard, P; De Marco, A; Rad, H D; Harbizadeh, A; Jahedi, F; Mohammadi, M J; Savari, J; Sadeghi, S; Kaabi, Z; Omidi Khaniabadi, Y

    2017-07-01

    This study assessed the effects of particulate matter (PM), equal or less than 10 μm in aerodynamic diameter (PM10), from the Middle-Eastern Dust events on public health in the megacity of Kermanshah (Iran). This study used epidemiological modeling and monitored ambient air quality data to estimate the potential PM10 impacts on public health. The AirQ2.2.3 model was used to calculate mortality and morbidity attributed to PM10 as representative of dust events. Using Visual Basic for Applications, the programming language of Excel software, hourly PM10 concentrations obtained from the local agency were processed to prepare input files for the AirQ2.2.3 model. Using baseline incidence, defined by the World Health Organization, the number of estimated excess cases for respiratory mortality, hospital admissions for chronic obstructive pulmonary disease, for respiratory diseases, and for cardiovascular diseases were 37, 39, 476, and 184 persons, respectively, from 21st March, 2014 to 20th March, 2015. Furthermore, 92% of mortality and morbidity cases occurred in days with PM10 concentrations lower than 150 μg/m(3). The highest percentage of person-days occurred for daily concentrations range of 100-109 μg/m(3), causing the maximum health end-points among the citizens of Kermanshah. Calculating the number of cumulative excess cases for mortality or morbidity attributed to PM10 provides a good tool for decision and policy-makers in the field of health care to compensate their shortcomings particularly at hospital and healthcare centers for combating dust storms. To diminish these effects, several immediate actions should be managed in the governmental scale to control dust such as spreading mulch and planting new species that are compatible to arid area. Copyright © 2017 The Royal Society for Public Health. All rights reserved.

  17. Simulation of Flash-Flood-Producing Storm Events in Saudi Arabia Using the Weather Research and Forecasting Model

    KAUST Repository

    Deng, Liping

    2015-05-01

    The challenges of monitoring and forecasting flash-flood-producing storm events in data-sparse and arid regions are explored using the Weather Research and Forecasting (WRF) Model (version 3.5) in conjunction with a range of available satellite, in situ, and reanalysis data. Here, we focus on characterizing the initial synoptic features and examining the impact of model parameterization and resolution on the reproduction of a number of flood-producing rainfall events that occurred over the western Saudi Arabian city of Jeddah. Analysis from the European Centre for Medium-Range Weather Forecasts (ECMWF) interim reanalysis (ERA-Interim) data suggests that mesoscale convective systems associated with strong moisture convergence ahead of a trough were the major initial features for the occurrence of these intense rain events. The WRF Model was able to simulate the heavy rainfall, with driving convective processes well characterized by a high-resolution cloud-resolving model. The use of higher (1 km vs 5 km) resolution along the Jeddah coastline favors the simulation of local convective systems and adds value to the simulation of heavy rainfall, especially for deep-convection-related extreme values. At the 5-km resolution, corresponding to an intermediate study domain, simulation without a cumulus scheme led to the formation of deeper convective systems and enhanced rainfall around Jeddah, illustrating the need for careful model scheme selection in this transition resolution. In analysis of multiple nested WRF simulations (25, 5, and 1 km), localized volume and intensity of heavy rainfall together with the duration of rainstorms within the Jeddah catchment area were captured reasonably well, although there was evidence of some displacements of rainstorm events.

  18. Emergency hospital visits in association with volcanic ash, dust storms and other sources of ambient particles: a time-series study in Reykjavík, Iceland.

    Science.gov (United States)

    Carlsen, Hanne Krage; Gislason, Thorarinn; Forsberg, Bertil; Meister, Kadri; Thorsteinsson, Throstur; Jóhannsson, Thorsteinn; Finnbjornsdottir, Ragnhildur; Oudin, Anna

    2015-04-13

    Volcanic ash contributed significantly to particulate matter (PM) in Iceland following the eruptions in Eyjafjallajökull 2010 and Grímsvötn 2011. This study aimed to investigate the association between different PM sources and emergency hospital visits for cardiorespiratory causes from 2007 to 2012. Indicators of PM10 sources; "volcanic ash", "dust storms", or "other sources" (traffic, fireworks, and re-suspension) on days when PM10 exceeded the daily air quality guideline value of 50 µg/m3 were entered into generalized additive models, adjusted for weather, time trend and co-pollutants. The average number of daily emergency hospital visits was 10.5. PM10 exceeded the air quality guideline value 115 out of 2191 days; 20 days due to volcanic ash, 14 due to dust storms (two days had both dust storm and ash contribution) and 83 due to other sources. High PM10 levels from volcanic ash tended to be significantly associated with the emergency hospital visits; estimates ranged from 4.8% (95% Confidence Interval (CI): 0.6, 9.2%) per day of exposure in unadjusted models to 7.3% (95% CI: -0.4, 15.5%) in adjusted models. Dust storms were not consistently associated with daily emergency hospital visits and other sources tended to show a negative association. We found some evidence indicating that volcanic ash particles were more harmful than particles from other sources, but the results were inconclusive and should be interpreted with caution.

  19. OBSERVATIONAL STUDIES ON SAND-DUST STORM IN HELAN MOUNTAINOUS AREA

    Institute of Scientific and Technical Information of China (English)

    牛生杰; 章澄昌; 孙继明; 樊曙先

    2001-01-01

    According to the observation of the number and mass concentration spectra of atmospheric aerosols, the total suspended particulates (TSP) and their size distribution, micrometeorology,and the solar spectroscopic radiation, even neutron activation treatment of sand dust samples in Helan Mountainous area, the formation law of floating dust, blowing sand and sandstorm weather and the characteristics of climatic variation in this area and the influence of the Helan Mountain are counted and analyzed. In addition, the spectrum characteristics, optical depth and chemical composition of sand aerosol particles are also analyzed and discussed.

  20. Numerical Modeling of Orbit-Spin Coupling Accelerations in a Mars General Circulation Model: Implications for Global Dust Storm Activity

    CERN Document Server

    Mischna, Michael A

    2016-01-01

    We employ the MarsWRF general circulation model (GCM) to test the predictions of a new physical hypothesis: a weak coupling of the orbital and rotational angular momenta of extended bodies is predicted to give rise to cycles of intensification and relaxation of circulatory flows within atmospheres. The dynamical core of the GCM has been modified to include the orbit-spin coupling accelerations due to solar system dynamics for the years 1920-2030. The modified GCM is first subjected to extensive testing and validation. We compare forced and unforced model outcomes for large-scale zonal and meridional flows, and for near-surface wind velocities and surface wind stresses. The predicted cycles of circulatory intensification and relaxation within the modified GCM are observed. Most remarkably, the modified GCM reproduces conditions favorable for the occurrence of perihelion-season global-scale dust storms on Mars in years in which such storms were observed. A strengthening of the meridional overturning (Hadley) ci...

  1. Study and case simulation of a regional dust model coupled with a nonhydrostatic dynamics model

    Institute of Scientific and Technical Information of China (English)

    CHENG Conglan; WANG Yingchun; LIU Weidong; ZHANG Xiaoling; XU Xiaofeng; XIE Pu

    2004-01-01

    A new regional dust model suitable for simulation and forecasting of dust storms over northern China was described. The dust model was developed by coupling the mesoscale dynamics model MM5 (the Fifth-Generation NCAR/Penn State Mesoscale Model) with a set of mass conservation equations for the particles. The model includes all the atmospheric physical processes of dust storms including occurrence, lifting, transport, and dry and wet deposition. It considers the parameterization of dry and wet deposition, the dust size distribution and microphysical processes in detail. The dust flux from the surface is parameterized based on the friction velocity, which is provided by the mesoscale nonhydrostatic dynamics model, which takes account of the vegetation coverage, land use, soil category, and soil moisture. This new dust model is used to simulate the dust storm that occurred on 19-21 March, 2002 in North China. The results show that there is high dust concentration and its movement is consistent with the surface weather record and satellite monitoring images of the observed dust storm. The simulated dust concentration coincides with the observation data of the particulate concentration of PM10 (dust particles smaller than 10 μm in diameter). The new numerical model also successfully simulates the formation and migration of the dust storm of 6-8 April, 2002 in North China.

  2. The hourly updated US High-Resolution Rapid Refresh (HRRR) storm-scale forecast model

    Science.gov (United States)

    Alexander, Curtis; Dowell, David; Benjamin, Stan; Weygandt, Stephen; Olson, Joseph; Kenyon, Jaymes; Grell, Georg; Smirnova, Tanya; Ladwig, Terra; Brown, John; James, Eric; Hu, Ming

    2016-04-01

    The 3-km convective-allowing High-Resolution Rapid Refresh (HRRR) is a US NOAA hourly updating weather forecast model that use a specially configured version of the Advanced Research WRF (ARW) model and assimilate many novel and most conventional observation types on an hourly basis using Gridpoint Statistical Interpolation (GSI). Included in this assimilation is a procedure for initializing ongoing precipitation systems from observed radar reflectivity data (and proxy reflectivity from lightning and satellite data), a cloud analysis to initialize stable layer clouds from METAR and satellite observations, and special techniques to enhance retention of surface observation information. The HRRR is run hourly out to 15 forecast hours over a domain covering the entire conterminous United States using initial and boundary conditions from the hourly-cycled 13km Rapid Refresh (RAP, using similar physics and data assimilation) covering North America and a significant part of the Northern Hemisphere. The HRRR is continually developed and refined at NOAA's Earth System Research Laboratory, and an initial version was implemented into the operational NOAA/NCEP production suite in September 2014. Ongoing experimental RAP and HRRR model development throughout 2014 and 2015 has culminated in a set of data assimilation and model enhancements that will be incorporated into the first simultaneous upgrade of both the operational RAP and HRRR that is scheduled for spring 2016 at NCEP. This presentation will discuss the operational RAP and HRRR changes contained in this upgrade. The RAP domain is being expanded to encompass the NAM domain and the forecast lengths of both the RAP and HRRR are being extended. RAP and HRRR assimilation enhancements have focused on (1) extending surface data assimilation to include mesonet observations and improved use of all surface observations through better background estimates of 2-m temperature and dewpoint including projection of 2-m temperature

  3. Towards a system for sea state forecasts in the Bulgarian Black Sea coastal zone: the case of the storm of 07-08 february 2012

    CERN Document Server

    Galabov, Vasko; Dimitrova, Marieta

    2012-01-01

    The paper describes the existing operational sea state forecast system of NIMH- BAS for sea state in the Black Sea and our current progress on the implementation of an additional component for the forecasts of wind waves in the Bulgarian coastal zone. Wind Waves and especially the extreme ones, occurring during severe storms are a major hazard for the coastal zone, causing significant damages to the infrastructure, threat for the human lives and also causing significant damages to the protected areas around the coast. The numerical model WAVEWATCH III is in use for wind waves forecasts for the entire Black Sea with horizontal resolution of 1/8 degree (roughly 14 kilometers), which is sufficient for the open Sea, but not enough for a detailed coastal forecast. For the purposes of the coastal forecasts and early warnings in case of severe storms we decided to implement SWAN (Simulating the Waves Near Shore)- development of TU- DELFT. In this paper we will describe the brief details about the coastal sea state f...

  4. Probabilistic Forecasting of Coastal Morphodynamic Storm Response at Fire Island, New York

    Science.gov (United States)

    Wilson, K.; Adams, P. N.; Hapke, C. J.; Lentz, E. E.; Brenner, O.

    2013-12-01

    Site-specific probabilistic models of shoreline change are useful because they are derived from direct observations so that local factors, which greatly influence coastal response, are inherently considered by the model. Fire Island, a 50-km barrier island off Long Island, New York, is periodically subject to large storms, whose waves and storm surge dramatically alter beach morphology. Nor'Ida, which impacted the Fire Island coast in 2009, was one of the larger storms to occur in the early 2000s. In this study, we improve upon a Bayesian Network (BN) model informed with historical data to predict shoreline change from Nor'Ida. We present two BN models, referred to as 'original' model (BNo) and 'revised' model (BNr), designed to predict the most probable magnitude of net shoreline movement (NSM), as measured at 934 cross-shore transects, spanning 46 km. Both are informed with observational data (wave impact hours, shoreline and dune toe change rates, pre-storm beach width, and measured NSM) organized within five nodes, but the revised model contains a sixth node to represent the distribution of material added during an April 2009 nourishment project. We evaluate model success by examining the percentage of transects on which the model chooses the correct (observed) bin value of NSM. Comparisons of observed to model-predicted NSM show BNr has slightly higher predictive success over the total study area and significantly higher success at nourished locations. The BNo, which neglects anthropogenic modification history, correctly predicted the most probable NSM in 66.6% of transects, with ambiguous prediction at 12.7% of the locations. BNr, which incorporates anthropogenic modification history, resulted in 69.4% predictive accuracy and 13.9% ambiguity. However, across nourished transects, BNr reported 72.9% predictive success, while BNo reported 61.5% success. Further, at nourished transects, BNr reported higher ambiguity of 23.5% compared to 9.9% in BNo. These results

  5. Atmospheric Motion Vectors from INSAT-3D: Initial quality assessment and its impact on track forecast of cyclonic storm NANAUK

    Science.gov (United States)

    Deb, S. K.; Kishtawal, C. M.; Kumar, Prashant; Kiran Kumar, A. S.; Pal, P. K.; Kaushik, Nitesh; Sangar, Ghansham

    2016-03-01

    The advanced Indian meteorological geostationary satellite INSAT-3D was launched on 26 July 2013 with an improved imager and an infrared sounder and is placed at 82°E over the Indian Ocean region. With the advancement in retrieval techniques of different atmospheric parameters and with improved imager data have enhanced the scope for better understanding of the different tropical atmospheric processes over this region. The retrieval techniques and accuracy of one such parameter, Atmospheric Motion Vectors (AMV) has improved significantly with the availability of improved spatial resolution data along with more options of spectral channels in the INSAT-3D imager. The present work is mainly focused on providing brief descriptions of INSAT-3D data and AMV derivation processes using these data. It also discussed the initial quality assessment of INSAT-3D AMVs for a period of six months starting from 01 February 2014 to 31 July 2014 with other independent observations: i) Meteosat-7 AMVs available over this region, ii) in-situ radiosonde wind measurements, iii) cloud tracked winds from Multi-angle Imaging Spectro-Radiometer (MISR) and iv) numerical model analysis. It is observed from this study that the qualities of newly derived INSAT-3D AMVs are comparable with existing two versions of Meteosat-7 AMVs over this region. To demonstrate its initial application, INSAT-3D AMVs are assimilated in the Weather Research and Forecasting (WRF) model and it is found that the assimilation of newly derived AMVs has helped in reduction of track forecast errors of the recent cyclonic storm NANAUK over the Arabian Sea. Though, the present study is limited to its application to one case study, however, it will provide some guidance to the operational agencies for implementation of this new AMV dataset for future applications in the Numerical Weather Prediction (NWP) over the south Asia region.

  6. On the influence of space storms on the frequency of infarct-myocardial, brain strokes, and hard car accidents; possible using of CR for their forecasting

    Science.gov (United States)

    Dorman, L. I.; Iucci, N.; Ptitsyna, N. G.; Villoresi, G.

    We consider the influence of space storms as strong interplanetary shock waves causing great cosmic ray Forbush-decreases and big geomagnetic storms on the people health at the ground level We used data of more than 7 millions ambulance cases in Moscow and St Petersburg included information on daily numbers of the hard traffic accidents infarctions and brain strokes We found that during space storms the average daily numbers of hard traffic accidents with using ambulances as well as infarctions and brain strokes confirmed by medical personal increase by 17 4 pm 3 1 10 5 pm 1 2 and 7 0 pm 1 7 respectively We show that the forecasting of these dangerous apace phenomena can be done partly by using cosmic ray data on pre-increase and pre-decrease effects as well as on the change of 3-D cosmic ray anisotropy

  7. Epifluorescent direct counts of bacteria and viruses from topsoil of various desert dust storm regions

    Science.gov (United States)

    Gonzalez-Martin, Cristina; Teigell-Perez, Nuria; Lyles, Mark; Valladares, Basilio; Griffin, Dale W.

    2013-01-01

    Topsoil from arid regions is the main source of dust clouds that move through the earth's atmosphere, and microbial communities within these soils can survive long-range dispersion. Microbial abundance and chemical composition were analyzed in topsoil from various desert regions. Statistical analyses showed that microbial direct counts were strongly positively correlated with calcium concentrations and negatively correlated with silicon concentrations. While variance between deserts was expected, it was interesting to note differences between sample sites within a given desert region, illustrating the 'patchy' nature of microbial communities in desert environments.

  8. El Niño-Southern Oscillation influence on the dust storm activity in Australia: Can the past provide a key to the future?

    Science.gov (United States)

    Pudmenzky, C.; Stone, R.; Allan, R.; Butler, H.

    2011-12-01

    Wind erosion is an internationally recognised land degradation problem and affects approximately 28% of the global land area. The Australian continent is the largest dust source in the Southern Hemisphere with an emission rate of around 100 Tg yr-1 or approximate 5% of the global total. The climate (especially eastern Australian climate) is greatly influenced by the El Niño-Southern Oscillation (ENSO) which is the strongest natural fluctuation of climate on interannual time-scales and also affects climate conditions globally. ENSO is the core driver of extreme weather events such as drought, flooding, bushfires, dust storms and tropical cyclones and up to 50% of annual rainfall variability in northern and eastern Australia is linked to ENSO. These drier conditions will reduce vegetation cover and result in an increased dust storm activity in the future in central eastern Australia during dry El Niño phases of the Southern Oscillation. The Lake Eyre Basin, Channel Country and the Mallee region are the main dust source areas and severe dust storms have the potential to transport millions of tonnes of fertile topsoil from inland Australia to places as far as New Zealand, New Caledonia and Antarctic. The research project will investigate the influence of the ENSO on dust storm activity in Australia. This will be achieved through major reanalysis of past climate conditions for the past 150 years or more using the global 'Atmospheric Circulation Reconstruction over the Earth' (ACRE) project outputs which will reconstruct both upper-air dynamics, surface conditions and then all major dust storm events of the past. Australia has one of the most variable rainfall climates in the world and observational and modelling results suggest that more frequent or stronger ENSO events are possible in the future. Drought in Australia is probably the most economically costly climate event and has environmental and social impacts by reducing agricultural output and having social

  9. The eSurge-Venice project: altimeter and scatterometer satellite data to improve the storm surge forecasting in the city of Venice

    Science.gov (United States)

    Zecchetto, Stefano; De Biasio, Francesco; Umgiesser, Georg; Bajo, Marco; Vignudelli, Stefano; Papa, Alvise; Donlon, Craig; Bellafiore, Debora

    2013-04-01

    On the framework of the Data User Element (DUE) program, the European Space Agency is funding a project to use altimeter Total Water Level Envelope (TWLE) and scatterometer wind data to improve the storm surge forecasting in the Adriatic Sea and in the city of Venice. The project will: a) Select a number of Storm Surge Events occurred in the Venice lagoon in the period 1999-present day b) Provide the available satellite Earth Observation (EO) data related to the Storm Surge Events, mainly satellite winds and altimeter data, as well as all the available in-situ data and model forecasts c) Provide a demonstration Near Real Time service of EO data products and services in support of operational and experimental forecasting and warning services d) Run a number of re-analysis cases, both for historical and contemporary storm surge events, to demonstrate the usefulness of EO data The re-analysis experiments, based on hindcasts performed by the finite element 2-D oceanographic model SHYFEM (https://sites.google.com/site/shyfem/), will 1. use different forcing wind fields (calibrated and not calibrated with satellite wind data) 2. use Storm Surge Model initial conditions determined from altimeter TWLE data. The experience gained working with scatterometer and Numerical Weather Prediction (NWP) winds in the Adriatic Sea tells us that the bias NWP-Scatt wind is negative and spatially and temporally not uniform. In particular, a well established point is that the bias is higher close to coasts then offshore. Therefore, NWP wind speed calibration will be carried out on each single grid point in the Adriatic Sea domain over the period of a Storm Surge Event, taking into account of existing published methods. Point #2 considers two different methodologies to be used in re-analysis tests. One is based on the use of the TWLE values from altimeter data in the Storm Surge Model (SSM), applying data assimilation methodologies and trying to optimize the initial conditions of the

  10. Observed particle sizes and fluxes of Aeolian sediment in the near surface layer during sand-dust storms in the Taklamakan Desert

    Science.gov (United States)

    Huo, Wen; He, Qing; Yang, Fan; Yang, Xinghua; Yang, Qing; Zhang, Fuyin; Mamtimin, Ali; Liu, Xinchun; Wang, Mingzhong; Zhao, Yong; Zhi, Xiefei

    2016-08-01

    Monitoring, modeling and predicting the formation and movement of dust storms across the global deserts has drawn great attention in recent decades. Nevertheless, the scarcity of real-time observations of the wind-driven emission, transport and deposition of dusts has severely impeded progress in this area. In this study, we report an observational analysis of sand-dust storm samples collected at seven vertical levels from an 80-m-high flux tower located in the hinterland of the great Taklamakan Desert for ten sand-dust storm events that occurred during 2008-2010. We analyzed the vertical distribution of sandstorm particle grain sizes and horizontal sand-dust sediment fluxes from the near surface up to 80 m high in this extremely harsh but highly representative environment. The results showed that the average sandstorm grain size was in the range of 70 to 85 μm. With the natural presence of sand dunes and valleys, the horizontal dust flux appeared to increase with height within the lower surface layer, but was almost invariant above 32 m. The average flux values varied within the range of 8 to 14 kg m-2 and the vertical distribution was dominated by the wind speed in the boundary layer. The dominant dust particle size was PM100 and below, which on average accounted for 60-80 % of the samples collected, with 0.9-2.5 % for PM0-2.5, 3.5-7.0 % for PM0-10, 5.0-14.0 % for PM0-20 and 20.0-40.0 % for PM0-50. The observations suggested that on average the sand-dust vertical flux potential is about 0.29 kg m-2 from the top of the 80 m tower to the upper planetary boundary layer and free atmosphere through the transport of particles smaller than PM20. Some of our results differed from previous measurements from other desert surfaces and laboratory wind-dust experiments, and therefore provide valuable observations to support further improvement of modeling of sandstorms across different natural environmental conditions.

  11. Lichen elemental composition distinguishes anthropogenic emissions from dust storm inputs and differs among species: Evidence from Xilinhot, Inner Mongolia, China

    Science.gov (United States)

    Liu, Hua-Jie; Fang, Shi-Bo; Liu, Si-Wa; Zhao, Liang-Cheng; Guo, Xiu-Ping; Jiang, Yun-Jun; Hu, Jian-Sen; Liu, Xiao-Di; Xia, Yu; Wang, Yi-Dan; Wu, Qing-Feng

    2016-10-01

    To test the applicability of lichens in the biomonitoring of atmospheric elemental deposition in a typical steppe zone of Inner Mongolia, China, six foliose lichens (Physcia aipolia, PA; P. tribacia, PT; Xanthoria elegans, XE; X. mandschurica, XM; Xanthoparmelia camtschadalis, XPC; and Xp. tinctina, XPT) were sampled from the Xilin River Basin, Xilinhot, Inner Mongolia, China. Twenty-five elements (Al, Ba, Cd, Ce, Cr, Cs, Cu, Fe, K, La, Mn, Mo, Na, Ni, P, Pb, Sb, Sc, Sm, Tb, Th, Ti, Tl, V and Zn) in the lichens were analysed using inductively coupled plasma mass spectrometry (ICP-MS). The results show that Cd, Pb and Zn were mainly atmospheric in origin, whereas the other elements were predominantly of crustal origin. Compared with other studies, our data were higher in crustal element concentrations and lower in atmospheric element concentrations, matching with the frequent, severe dust storms and road traffic in the area. The elemental concentrations in lichens are both species- and element-specific, highlighting the importance of species selection for biomonitoring air pollution using lichens. We recommend PT, XE, XM and XPT for monitoring atmospheric deposition of crustal elements; XPC and XPT for Cd and Pb; PA for Cd and Zn; and PT for Cd.

  12. Lichen elemental composition distinguishes anthropogenic emissions from dust storm inputs and differs among species: Evidence from Xilinhot, Inner Mongolia, China

    Science.gov (United States)

    Liu, Hua-Jie; Fang, Shi-Bo; Liu, Si-Wa; Zhao, Liang-Cheng; Guo, Xiu-Ping; Jiang, Yun-Jun; Hu, Jian-Sen; Liu, Xiao-Di; Xia, Yu; Wang, Yi-Dan; Wu, Qing-Feng

    2016-01-01

    To test the applicability of lichens in the biomonitoring of atmospheric elemental deposition in a typical steppe zone of Inner Mongolia, China, six foliose lichens (Physcia aipolia, PA; P. tribacia, PT; Xanthoria elegans, XE; X. mandschurica, XM; Xanthoparmelia camtschadalis, XPC; and Xp. tinctina, XPT) were sampled from the Xilin River Basin, Xilinhot, Inner Mongolia, China. Twenty-five elements (Al, Ba, Cd, Ce, Cr, Cs, Cu, Fe, K, La, Mn, Mo, Na, Ni, P, Pb, Sb, Sc, Sm, Tb, Th, Ti, Tl, V and Zn) in the lichens were analysed using inductively coupled plasma mass spectrometry (ICP-MS). The results show that Cd, Pb and Zn were mainly atmospheric in origin, whereas the other elements were predominantly of crustal origin. Compared with other studies, our data were higher in crustal element concentrations and lower in atmospheric element concentrations, matching with the frequent, severe dust storms and road traffic in the area. The elemental concentrations in lichens are both species- and element-specific, highlighting the importance of species selection for biomonitoring air pollution using lichens. We recommend PT, XE, XM and XPT for monitoring atmospheric deposition of crustal elements; XPC and XPT for Cd and Pb; PA for Cd and Zn; and PT for Cd. PMID:27698382

  13. The impact of the winter North Atlantic Oscillation on the frequency of spring dust storms over Tarim Basin in northwest China in the past half-century

    Science.gov (United States)

    Zhao, Yong; Huang, Anning; Zhu, Xinsheng; Zhou, Yang; Huang, Ying

    2013-06-01

    The relationship between the frequency of spring dust storms over Tarim Basin in northwest China and the winter North Atlantic Oscillation (NAO) is investigated by using the observed dust storm frequency (DSF) and the 10 m wind velocity at 36 stations in Tarim Basin and the National Centers for Environment Prediction/National Center for Atmospheric Research reanalysis data for the period 1961-2007. The spring DSF (winter NAO) index shows a clear decreasing (increasing) linear trend over 1961-2007. The winter NAO correlates well with the subsequent spring DSF over Tarim Basin on both interannual and interdecadal time scales and its interannual to interdecadal variation plays an important role in the spring DSF. Two possible physical mechanisms are identified. One is related to the large scale anomalous circulations in spring in the middle to high troposphere modulated by the winter NAO, providing the background of dynamical conditions for the dust storm occurrences. The other is related to the shifts in the local horizontal sea level pressure (SLP) gradients and 10 m wind speed, corresponding to changes in the large scale circulations in spring. The decrease in the local 10 m wind speed due to the reduced horizontal SLP gradients over Tarim Basin during the strong winter NAO years contributes to the decline of the DSF in the subsequent spring.

  14. Storm Identification, Tracking and Forecasting Using High-Resolution Images of Short-Range X-Band Radar

    Directory of Open Access Journals (Sweden)

    Sajid Shah

    2015-05-01

    Full Text Available Rain nowcasting is an essential part of weather monitoring. It plays a vital role in human life, ranging from advanced warning systems to scheduling open air events and tourism. A nowcasting system can be divided into three fundamental steps, i.e., storm identification, tracking and nowcasting. The main contribution of this work is to propose procedures for each step of the rain nowcasting tool and to objectively evaluate the performances of every step, focusing on two-dimension data collected from short-range X-band radars installed in different parts of Italy. This work presents the solution of previously unsolved problems in storm identification: first, the selection of suitable thresholds for storm identification; second, the isolation of false merger (loosely-connected storms; and third, the identification of a high reflectivity sub-storm within a large storm. The storm tracking step of the existing tools, such as TITANand SCIT, use only up to two storm attributes, i.e., center of mass and area. It is possible to use more attributes for tracking. Furthermore, the contribution of each attribute in storm tracking is yet to be investigated. This paper presents a novel procedure called SALdEdA (structure, amplitude, location, eccentricity difference and areal difference for storm tracking. This work also presents the contribution of each component of SALdEdA in storm tracking. The second order exponential smoothing strategy is used for storm nowcasting, where the growth and decay of each variable of interest is considered to be linear. We evaluated the major steps of our method. The adopted techniques for automatic threshold calculation are assessed with a 97% goodness. False merger and sub-storms within a cluster of storms are successfully handled. Furthermore, the storm tracking procedure produced good results with an accuracy of 99.34% for convective events and 100% for stratiform events.

  15. Artificial Neural Network forecasting of storm surge water levels at major estuarine ports to supplement national tide-surge models and improve port resilience planning

    Science.gov (United States)

    French, Jon; Mawdsley, Robert; Fujiyama, Taku; Achuthan, Kamal

    2017-04-01

    Effective prediction of tidal storm surge is of considerable importance for operators of major ports, since much of their infrastructure is necessarily located close to sea level. Storm surge inundation can damage critical elements of this infrastructure and significantly disrupt port operations and downstream supply chains. The risk of surge inundation is typically approached using extreme value analysis, while short-term forecasting generally relies on coastal shelf-scale tide and surge models. However, extreme value analysis does not provide information on the duration of a surge event and can be sensitive to the assumptions made and the historic data available. Also, whilst regional tide and surge models perform well along open coasts, their fairly coarse spatial resolution means that they do not always provide accurate predictions for estuarine ports. As part of a NERC Environmental Risks to Infrastructure Innovation Programme project, we have developed a tool that is specifically designed to forecast the North Sea storm surges on major ports along the east coast of the UK. Of particular interest is the Port of Immingham, Humber estuary, which handles the largest volume of bulk cargo in the UK including major flows of coal and biomass for power generation. A tidal surge in December 2013, with an estimated return period of 760 years, partly flooded the port, damaged infrastructure and disrupted operations for several weeks. This and other recent surge events highlight the need for additional tools to supplement the national UK Storm Tide Warning Service. Port operators are also keen to have access to less computationally expensive forecasting tools for scenario planning and to improve their resilience to actual events. In this paper, we demonstrate the potential of machine learning methods based on Artificial Neural Networks (ANNs) to generate accurate short-term forecasts of extreme water levels at estuarine North Sea ports such as Immingham. An ANN is

  16. High-throughput sequencing analysis of the bacteria in the dust storm which passed over Canberra, Australia on 22-23 September 2009

    Science.gov (United States)

    Munday, Chris; De Deckker, Patrick; Tapper, Nigel; Allison, Gwen

    2014-05-01

    Following a prolonged drought in Australia in the first decade of the 21st century, several dust storms affected the heavily populated East coast of Australia. The largest such storm occurred on 22-23 September 2009 and had a front of an estimated 3000km. A 24hr average PM10 concentration of over 2,000μg/m3 was recorded in several locations and an hourly peak of over 15,000μg/m3 was recorded (Leys et al. 2011). Over two time periods duplicate aerosol samples were collected on 47mm diameter cellulose nitrate membranes at a location removed from anthropogenic influences. One set of samples was collected in the afternoon the dust event started and another was collected overnight. Additionally, overnight rainfall was collected in a sterile bottle.DNA was directly extracted one membrane from each time point for molecular cloning and high throughput sequencing, while the other was cultivated on Tryptic Soy Agar (TSA). High throughput sequencing was performed using the 454 Titanium platform. From the three samples, 19,945 curated sequences were obtained representing 942 OTUS, with the three samples approximately equal in number. Unclassified Rhizobiales and Stenotrophomonas were the most abundant groups which could be attributed names. A total of 942 OTUs were identified (cutoff = 0.03), and despite the temporal relation of the samples, only eleven were found in all three samples, indicating that the dust storm evolved in composition as it passed over the region. Approximately 800 and 500 CFU/m3 were found in the two cultivated samples, tenfold more than was collected from previous dust events (Lim et al, 2011). Identification of cultivars revealed a dominance of the gram positive Firmicutes phylum, while the clone library showed a more even distribution of taxa, with Actinobacteria the most common and Firmicutes comprising less than 10% of sequences. Collectively, the analyses indicate that the concentration of cultivable organisms during the dust storm dramatically

  17. Forecasting Winter Storms in the Sierra: A Social Science Perspective in Keeping the Public Safe without Negatively Impacting the Local Tourism Industry

    Science.gov (United States)

    Milne, R.; Wallmann, J.; Myrick, D. T.

    2010-12-01

    The National Weather Service Office in Reno is responsible for issuing Blizzard Warnings, Winter Storm Warnings, and Winter Weather Advisories for the Sierra, including the Lake Tahoe Basin and heavily traveled routes such as Interstate 80, Highway 395 and Highway 50. These forecast products prepare motorists for harsh travel conditions as well as those venturing into the backcountry, which are essential to the NWS mission of saving lives and property. During the winter season, millions of people from around the world visit the numerous world class ski resorts in the Sierra and the Lake Tahoe Basin, which is vital to the local economy. This situation creates a challenging decision for the forecasters to provide appropriate wording in winter statements to keep the public safe, without significantly impacting the local tourism-based economy. Numerous text and graphical products, including online weather briefings, are utilized by NWS Reno to highlight hazards in ensuring the public, businesses, and other government agencies are prepared for winter storms and take appropriate safety measures. The effectiveness of these product types will be explored, with past snowstorms used as examples to show how forecasters determine which type of text or graphical product is most appropriate to convey the hazardous weather threats.

  18. Chemical characteristics of PM2.5 during dust storms and air pollution events in Chengdu, China

    Institute of Scientific and Technical Information of China (English)

    Qiyuan Wang; Junji cao; Zhenxing Shen; Jun Tao; Shun Xiao; Lei Luo; Qingyang He

    2013-01-01

    Daily fine particulate (PM2.5) samples were collected in Chengdu from April 2009 to February 2010 to investigate their chemical profiles during dust storms (DSs) and several types of pollution events,including haze (HDs),biomass burning (BBs),and fireworks displays (FDs).The highest PM2.s mass concentrations were found during DSs (283.3 μg/m3),followed by FDs (212.7 μg/m3),HDs (187.3 μg/m3),and BBs (130.1 μg/m3).The concentrations of most elements were elevated during DSs and pollution events,except for BBs.Secondary inorganic ions (NO3-,SO42-and NH4+) were enriched during HDs,while PM2.5 from BBs showed high K+ but low SO42-.FDs caused increases in K+ and enrichment in SO42.Ca2+ was abundant in DS samples.Ion-balance calculations indicated that PM2.5 from HDs and FDs was more acidic than on normal days,but DS and BB particles were alkaline.The highest organic carbon (OC) concentration was 26.1 μg/m3 during FDs,followed by BBs (23.6 lμg/m3),HDs (19.6 μg/m3),and DSs (18.8 iμg/m3).In contrast,elemental carbon (EC) concentration was more abundant during HDs (10.6 μg/m3) and FDs (9.5 μg/m3) than during BBs (6.2 μg/m3) and DSs (6.0 μg/m3).The highest OC/EC ratios were obtained during BBs,with the lowest during HDs.SO42-/K+ and TCA/SO42 ratios proved to be effective indicators for differentiating pollution events.Mass balance showed that organic matter,SO42-,and NO3-were the dominant chemical components during pollution events,while soil dust was dominant during DSs.

  19. The Effects of PM2.5 from Asian Dust Storms on Emergency Room Visits for Cardiovascular and Respiratory Diseases.

    Science.gov (United States)

    Liu, Ssu-Ting; Liao, Chu-Yung; Kuo, Cheng-Yu; Kuo, Hsien-Wen

    2017-04-16

    A case-crossover study examined how PM2.5 from Asian Dust Storms (ADS) affects the number of emergency room (ER) admissions for cardiovascular diseases (CVDs) and respiratory diseases (RDs). Our data indicated that PM2.5 concentration from ADS was highly correlated with ER visits for CVDs and RDs. The odds ratios (OR) increased by 2.92 (95% CI: 1.22-5.08) and 1.86 (95% CI: 1.30-2.91) per 10 µg/m³ increase in PM2.5 levels, for CVDs and RDs, respectively. A 10 µg/m³ increase in PM2.5 from ADSs was significantly associated with an increase in ER visits for CVDs among those 65 years of age and older (an increase of 2.77 in OR) and for females (an increase of 3.09 in OR). In contrast, PM2.5 levels had a significant impact on RD ER visits among those under 65 years of age (OR = 1.77). The risk of ER visits for CVDs increased on the day when the ADS occurred in Taiwan and the day after (lag 0 and lag 1); the corresponding risk increase for RDs only increased on the fifth day after the ADS (lag 5). In Taiwan's late winter and spring, the severity of ER visits for CVDs and RDs increases. Environmental protection agencies should employ an early warning system for ADS to reduce high-risk groups' exposure to PM2.5.

  20. Assessment of storm forecast

    DEFF Research Database (Denmark)

    Cutululis, Nicolaos Antonio; Hahmann, Andrea N.; Huus Bjerge, Martin

    When wind speed exceeds a certain value, wind turbines shut-down in order to protect their structure. This leads to sudden wind plants shut down and to new challenges concerning the secure operation of the pan-European electric system with future large scale offshore wind power. This task aims at...

  1. The Circulation Characteristics Of Dust Pollution In Analysis And Forecast In Hohhot Area%呼和浩特地区沙尘污染的环流特征分析与预报

    Institute of Scientific and Technical Information of China (English)

    李浩

    2013-01-01

    days less.When spring Pacific SST is the typical state of El nino (La Nina), in the same period of sand dust days more (less), and vice versa.Through the circulation background of typical numerical sim-ulation and diagnosis analysis , find out the way of dust weather forecast:In dust storms occur in the instability of the atmosphere, the associ -ated with the energy accumulation and release, with the strong development of Mongolia cyclone and ground cold front ,the mesoscale shear line triggered the dust .MODIS satellite also has certain prediction for dust monitoring.

  2. The Effect of Dust Storm on the Microbial Quality of Ambient Air in Sanandaj: A City Located in the West of Iran

    OpenAIRE

    2015-01-01

    Background and Aims: The presence of pathogenic microorganisms in the dust storm can cause diseases such as Asthma, Pneumonia, and respiratory infections. The aim of this study was to determine the relationship between air-borne particles with airborne microorganisms in normal and dusty days in Sanandaj, a city located in the west of Iran. Materials and Methods: Air sampling was conducted during the normal and dusty days through Andersen single-stage impactor (28.3 L/min) for 2.5 min. Air par...

  3. Forecasting, Forecasting

    Science.gov (United States)

    Michael A. Fosberg

    1987-01-01

    Future improvements in the meteorological forecasts used in fire management will come from improvements in three areas: observational systems, forecast techniques, and postprocessing of forecasts and better integration of this information into the fire management process.

  4. Effect of wind speed and relative humidity on atmospheric dust concentrations in semi-arid climates.

    Science.gov (United States)

    Csavina, Janae; Field, Jason; Félix, Omar; Corral-Avitia, Alba Y; Sáez, A Eduardo; Betterton, Eric A

    2014-07-15

    Atmospheric particulate have deleterious impacts on human health. Predicting dust and aerosol emission and transport would be helpful to reduce harmful impacts but, despite numerous studies, prediction of dust events and contaminant transport in dust remains challenging. In this work, we show that relative humidity and wind speed are both determinants in atmospheric dust concentration. Observations of atmospheric dust concentrations in Green Valley, AZ, USA, and Juárez, Chihuahua, México, show that PM10 concentrations are not directly correlated with wind speed or relative humidity separately. However, selecting the data for high wind speeds (>4m/s at 10 m elevation), a definite trend is observed between dust concentration and relative humidity: dust concentration increases with relative humidity, reaching a maximum around 25% and it subsequently decreases with relative humidity. Models for dust storm forecasting may be improved by utilizing atmospheric humidity and wind speed as main drivers for dust generation and transport.

  5. Effect of Wind Speed and Relative Humidity on Atmospheric Dust Concentrations in Semi-Arid Climates

    Science.gov (United States)

    Csavina, Janae; Field, Jason; Félix, Omar; Corral-Avitia, Alba Y.; Sáez, A. Eduardo; Betterton, Eric A.

    2014-01-01

    Atmospheric particulate have deleterious impacts on human health. Predicting dust and aerosol emission and transport would be helpful to reduce harmful impacts but, despite numerous studies, prediction of dust events and contaminant transport in dust remains challenging. In this work, we show that relative humidity and wind speed are both determinants in atmospheric dust concentration. Observations of atmospheric dust concentrations in Green Valley, AZ, USA, and Juárez, Chihuahua, México, show that PM10 concentrations are not directly correlated with wind speed or relative humidity separately. However, selecting the data for high wind speeds (> 4 m/s at 10 m elevation), a definite trend is observed between dust concentration and relative humidity: dust concentration increases with relative humidity, reaching a maximum around 25% and it subsequently decreases with relative humidity. Models for dust storm forecasting may be improved by utilizing atmospheric humidity and wind speed as main drivers for dust generation and transport. PMID:24769193

  6. Experimental effects of sand-dust storm on tolerance index, percentage phototoxicity and chlorophyll a fluorescence of Vigna radiata L.

    Directory of Open Access Journals (Sweden)

    M. Alavi

    2015-03-01

    Full Text Available In arid and semi-arid parts of the world excessive mineral aerosol carried by air parcels is a common climatic incident with well-known environmental side effects. In this way, we studied the role of sand-dust accumulation on various aspects of productivity of Vigna radiata L. including dry mass (DM, chlorophyll (Chl a, b, Chlorophyll a fluorescence (effective quantum yield of PSII photochemistry (ФPSII, maximal quantum yield of PSII photochemistry (Fv/Fm and electron transport rate (ETR. V. radiata was exposed to a gradient of dust concentrations in a dust chamber (0.5 (T1, 1(T2 and 1.5 g/m3 (T3 simulated by a dust generator for a period of 60 days. Results of this experiment indicate that DM and Chl content of shoot are negatively correlated with the intensity of the dust exposure. Exposure of V. radiata to dust compared with the control was caused 5% (T1, 14% (T2 and 27% (T3 reduction in leaf DM (p≤0.05, ANOVA. Also, exposure to the dust induced a significant (p≤0.05 reduction in the Total Chl content in (T3 25%. Also, we showed that ФPSII, ETR and Fv/Fm were affected by increasing of the dust concentrations. Exposure to the dust resulted in a significant reduction in ETR of 15%, 22%, and 43%.

  7. Wind modeling of Chihuahuan Desert dust outbreaks

    Science.gov (United States)

    Rivera Rivera, Nancy I.; Gill, Thomas E.; Gebhart, Kristi A.; Hand, Jennifer L.; Bleiweiss, Max P.; Fitzgerald, Rosa M.

    The Chihuahuan Desert region of North America is a significant source of mineral aerosols in the Western Hemisphere, and Chihuahuan Desert dust storms frequently impact the Paso del Norte (El Paso, USA/Ciudad Juarez, Mexico) metropolitan area. A statistical analysis of HYSPLIT back trajectory residence times evaluated airflow into El Paso on all days and on days with synoptic (non-convective) dust events in 2001-2005. The incremental probability—a measure of the areas most likely to have been traversed by air masses arriving at El Paso during dusty days—was only strongly positively associated with the region west-southwest of the city, a zone of known dust source areas. Focused case studies were made of major dust events on 15 April and 15 December 2003. Trajectories approached the surface and MM5 (NCAR/Penn State Mesoscale Model) wind speeds increased at locations consistent with dust sources observed in satellite imagery on those dates. Back trajectory and model analyses suggested that surface cyclones adjacent to the Chihuahuan Desert were associated with the extreme dust events, consistent with previous studies of dust storms in the Southern High Plains to the northeast. The recognition of these meteorological patterns serves as a forecast aid for prediction of dust events likely to impact the Paso del Norte.

  8. Chemical characteristics of PM2.5-0.3 and PM0.3 and consequence of a dust storm episode at an urban site in Lebanon

    Science.gov (United States)

    Borgie, Mireille; Ledoux, Frédéric; Dagher, Zeina; Verdin, Anthony; Cazier, Fabrice; Courcot, Lucie; Shirali, Pirouz; Greige-Gerges, Hélène; Courcot, Dominique

    2016-11-01

    Located on the eastern side of the Mediterranean Basin at the intersection of air masses circulating between three continents, the agglomeration of Beirut, capital of Lebanon is an important investigating area for air pollution and more studies are needed to elucidate the composition of the smallest particles classified as carcinogenic to humans. PM2.5-0.3 and PM0.3 samples were collected during the spring-summer period in an urban background site of Beirut, after a dust storm episode occurred, and their chemical composition was determined. Our findings showed that components formed by gas to particle conversion (SO42 - and NH4+) and related to combustion processes are mainly found in the PM0.3 fraction. Typical crustal (Ca2+, Fe, Ti, Mg2+), sea-salt (Na+, Cl-, Mg2+, Sr) species, and NO3- are mainly associated with the PM2.5-0.3 fraction. We have also evidenced that the dust episode which occurred in Lebanon in May 2011 originated from the Iraqian and Syrian deserts, which are the least studied, and had a direct influence on the composition of PM2.5-0.3 during the beginning of the first sampling period, and then an indirect and persistent influence by the re-suspension of deposited dust particles. Moreover, PAHs concentrations were much higher in PM0.3 than in PM2.5-0.3 and their composition appeared influenced by diesel (buses, trucks and generator sets) and gasoline (private cars) emissions.

  9. Maximum wind radius estimated by the 50 kt radius: improvement of storm surge forecasting over the western North Pacific

    Science.gov (United States)

    Takagi, Hiroshi; Wu, Wenjie

    2016-03-01

    Even though the maximum wind radius (Rmax) is an important parameter in determining the intensity and size of tropical cyclones, it has been overlooked in previous storm surge studies. This study reviews the existing estimation methods for Rmax based on central pressure or maximum wind speed. These over- or underestimate Rmax because of substantial variations in the data, although an average radius can be estimated with moderate accuracy. As an alternative, we propose an Rmax estimation method based on the radius of the 50 kt wind (R50). Data obtained by a meteorological station network in the Japanese archipelago during the passage of strong typhoons, together with the JMA typhoon best track data for 1990-2013, enabled us to derive the following simple equation, Rmax = 0.23 R50. Application to a recent strong typhoon, the 2015 Typhoon Goni, confirms that the equation provides a good estimation of Rmax, particularly when the central pressure became considerably low. Although this new method substantially improves the estimation of Rmax compared to the existing models, estimation errors are unavoidable because of fundamental uncertainties regarding the typhoon's structure or insufficient number of available typhoon data. In fact, a numerical simulation for the 2013 Typhoon Haiyan as well as 2015 Typhoon Goni demonstrates a substantial difference in the storm surge height for different Rmax. Therefore, the variability of Rmax should be taken into account in storm surge simulations (e.g., Rmax = 0.15 R50-0.35 R50), independently of the model used, to minimize the risk of over- or underestimating storm surges. The proposed method is expected to increase the predictability of major storm surges and to contribute to disaster risk management, particularly in the western North Pacific, including countries such as Japan, China, Taiwan, the Philippines, and Vietnam.

  10. Speciation of the elements and compositions on the surfaces of dust storm particles: The evidence for the coupling of iron with sulfur in aerosol during the long-range transport

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xingying; ZHUANG Guoshun; CHEN Jianmin; XUE Huaxin

    2005-01-01

    The speciation of the elements on the surface of the particles collected during dust storm and non-dust storm in Beijing and Inner Mongolia was studied by XPS. The major species of iron on the surface were oxides, sulfate, silicate, FeOOH and minor part sorbed on SiO2/Al2O3. Sulfate is the dominant species of sulfur on the surface. SiO2 and Al2O3 are the main components of Si and Al on the surface respectively. One of the most important findings was that the Fe(II) (FeS and FeSO4) produced could account for up to 44.3% and 45.6% of the total Fe on the surface in the aerosol sample collected at that night and next day of the "peak" time of the dust storm occurring on March 20, 2002, while Fe2(SO4)3, one of the Fe(III) species on the surface decreased from 67.1% to 49.5% and 48.0% respectively. Both S and Fe enriched on the surface of aerosol particles. Fe(II) accounted for 1.3%-5.3% of total Fe in bulk aerosol samples during dust storm. These results provided strong evidence to support the hypothesis of the coupling between iron and sulfur in aerosols during the long-range transport, which would have important impact on the global biogeochemical cycle.

  11. Storm surge variational assimilation model

    Directory of Open Access Journals (Sweden)

    Shi-li HUANG

    2010-06-01

    Full Text Available To eliminate errors caused by uncertainty of parameters and further improve capability of storm surge forecasting, the variational data assimilation method is applied to the storm surge model based on unstructured grid with high spatial resolution. The method can effectively improve the forecasting accuracy of storm surge induced by typhoon through controlling wind drag force coefficient parameter. The model is first theoretically validated with synthetic data. Then, the real storm surge process induced by the TC 0515 typhoon is forecasted by the variational data assimilation model, and results show the feasibility of practical application.

  12. Thyroid storm

    Science.gov (United States)

    Thyrotoxic storm; Hyperthyroid storm; Accelerated hyperthyroidism; Thyroid crisis; Thyrotoxicosis - thyroid storm ... Thyroid storm occurs due to a major stress such as trauma, heart attack , or infection. In rare ...

  13. The DREAMS experiment flown on the ExoMars 2016 mission for the study of Martian environment during the dust storm season

    Science.gov (United States)

    Bettanini, C.; Esposito, R.; Debei, S.; Molfese, C.; Colombatti, G.; Aboudan, A.; Brucato, J. R.; Cortecchia, F.; Di Achille, G.; Guizzo, G. P.; Friso, E.; Ferri, F.; Marty, L.; Mennella, V.; Molinaro, R.; Schipani, P.; Silvestro, S.; Mugnuolo, R.; Pirrotta, S.; Marchetti, E.; Harri, A.-M.; Montmessin, F.; Wilson, C.; Arruego Rodriguez, I.; Abbaki, S.; Apestigue, V.; Bellucci, G.; Berthelier, J. J.; Calcutt, S. B.; Forget, F.; Genzer, M.; Gilbert, P.; Haukka, H.; Jimenez, J. J.; Jimenez, S.; Josset, J. L.; Karatekin, O.; Landis, G.; Lorenz, R.; Martinez, J.; Möhlmann, D.; Moirin, D.; Palomba, E.; Pateli, M.; Pommereau, J.-P.; Popa, C. I.; Rafkin, S.; Rannou, P.; Renno, N. O.; Schmidt, W.; Simoes, F.; Spiga, A.; Valero, F.; Vazquez, L.; Vivat, F.; Witasse, O.

    2017-08-01

    The DREAMS (Dust characterization, Risk assessment and Environment Analyser on the Martian Surface) experiment on Schiaparelli lander of ExoMars 2016 mission was an autonomous meteorological station designed to completely characterize the Martian atmosphere on surface, acquiring data not only on temperature, pressure, humidity, wind speed and direction, but also on solar irradiance, dust opacity and atmospheric electrification, to measure for the first time key parameters linked to hazard conditions for future manned explorations. Although with very limited mass and energy resources, DREAMS would be able to operate autonomously for at least two Martian days (sols) after landing in a very harsh environment as it was supposed to land on Mars during the dust storm season (October 2016 in Meridiani Planum) relying on its own power supply. ExoMars mission was successfully launched on 14th March 2016 and Schiaparelli entered the Mars atmosphere on October 20th beginning its 'six minutes of terror' journey to the surface. Unfortunately, some unexpected behavior during the parachuted descent caused an unrecoverable critical condition in navigation system of the lander driving to a destructive crash on the surface. The adverse sequence of events at 4 km altitude triggered the transition of the lander in surface operative mode, commanding switch on the DREAMS instrument, which was therefore able to correctly power on and send back housekeeping data. This proved the nominal performance of all DREAMS hardware before touchdown demonstrating the highest TRL of the unit for future missions. This paper describes this experiment in terms of scientific goals, design, performances, testing and operational capabilities with an overview of in flight performances and available mission data.

  14. The Impact of Aerosols Generated from Biomass Burning, Dust Storms, and Volcanoes Upon the Earth's Radiative Energy Budget

    Science.gov (United States)

    Christopher, Sundar A.

    1997-01-01

    A new technique for detecting aerosols from biomass burning and dust is developed. The radiative forcing of aerosols is estimated over four major ecosystems in South America. A new smoke and fire detection scheme is developed for biomass burning aerosols over South America. Surface shortware irradiance calculations are developed in the presence of biomass burning aerosols during the SCAR-B experiment. This new approach utilizes ground based, aircraft, and satellite measurements.

  15. Evolution of Martian polar landscapes - Interplay of long-term variations in perennial ice cover and dust storm intensity

    Science.gov (United States)

    Cutts, J. A.; Blasius, K. R.; Roberts, W. J.

    1979-01-01

    The discovery of a new type of Martian polar terrain, called undulating plain, is reported and the evolution of the plains and other areas of the Martian polar region is discussed in terms of the trapping of dust by the perennial ice cover. High-resolution Viking Orbiter 2 observations of the north polar terrain reveal perennially ice-covered surfaces with low relief, wavelike, regularly spaced, parallel ridges and troughs (undulating plains) occupying areas of the polar terrain previously thought to be flat, and associated with troughs of considerable local relief which exhibit at least partial annual melting. It is proposed that the wavelike topography of the undulating plains originates from long-term periodic variations in cyclical dust precipitation at the margin of a growing or receding perennial polar cap in response to changes in insolation. The troughs are proposed to originate from areas of steep slope in the undulating terrain which have lost their perennial ice cover and have become incapable of trapping dust. The polar landscape thus appears to record the migrations, expansions and contractions of the Martian polar cap.

  16. Model simulation of storm surge potential for Andaman islands

    Digital Repository Service at National Institute of Oceanography (India)

    Kumar, V.S.; RameshBabu, V.; Babu, M.T.; Dhinakaran, G.; Rajamanickam, G.V.

    ) for storm surge forecasting at the eastern coast of India. Flather (1994) has applied another analytical model of Holland (1980) for wind and pressure fields in the case of surge simulation, forced by April 1991 Bangladesh storm. The basic atmospheric... parameters remain the same in all the parameterization schemes of storm wind field. Storm Surge Model Storm surge operational models are in use for a long time for forecasting and warning of storm surge disasters bordering the coasts in the parts of northern...

  17. Geoeffectiveness (D (sub st) and K (sub p)) of Interplanetary Coronal Mass Ejections During 1995-2009 and Implications for Storm Forecasting

    Science.gov (United States)

    Richardson, I. G.; Cane, H. V.

    2011-01-01

    We summarize the geoeffectiveness (based on the Dst and Kp indices) of the more than 300 interplanetary coronal mass ejections (ICMEs) that passed the Earth during 1996-2009, encompassing solar cycle 23. We subsequently estimate the probability that an ICME will generate geomagnetic activity that exceeds certain thresholds of Dst or Kp, including the NOAA "G" storm scale, based on maximum values of the southward magnetic field component (Bs), the solar wind speed (V), and the y component (Ey) of the solar wind convective electric field E = -V x B, in the ICME or sheath ahead of the ICME. Consistent with previous studies, the geoeffectiveness of an ICME is correlated with Bs or Ey approx.= VBs in the ICME or sheath, indicating that observations from a solar wind monitor upstream of the Earth are likely to provide the most reliable forecasts of the activity associated with an approaching ICME. There is also a general increase in geoeffectiveness with ICME speed, though the overall event-to-event correlation is weaker than for Bs and Ey. Nevertheless, using these results, we suggest that the speed of an ICME approaching the Earth inferred, for example, from routine remote sensing by coronagraphs on spacecraft well separated from the Earth or by all-sky imagers, could be used to estimate the likely geoeffectiveness of the ICME (our "comprehensive" ICME database provides a proxy for ICMEs identified in this way) with a longer lead time than may be possible using an upstream monitor

  18. Conducting and Evaluating Stakeholder Workshops to Facilitate Updates to a Storm Surge Forecasting Model for Coastal Louisiana

    Science.gov (United States)

    DeLorme, D.; Lea, K.; Hagen, S. C.

    2016-12-01

    As coastal Louisiana evolves morphologically, ecologically, and from engineering advancements, there is a crucial need to continually adjust real-time forecasting and coastal restoration planning models. This presentation discusses planning, conducting, and evaluating stakeholder workshops to support such an endeavor. The workshops are part of an ongoing Louisiana Sea Grant-sponsored project. The project involves updating an ADCIRC (Advanced Circulation) mesh representation of topography including levees and other flood control structures by applying previously-collected elevation data and new data acquired during the project. The workshops are designed to educate, solicit input, and ensure incorporation of topographic features into the framework is accomplished in the best interest of stakeholders. During this project's first year, three one-day workshops directed to levee managers and other local officials were convened at agricultural extension facilities in Hammond, Houma, and Lake Charles, Louisiana. The objectives were to provide a forum for participants to learn about the ADCIRC framework, understand the importance of accurate elevations for a robust surge model, discuss and identify additional data sources, and become familiar with the CERA (Coastal Emergency Risks Assessment) visualization tool. The workshop structure consisted of several scientific presentations with questions/answer time (ADCIRC simulation inputs and outputs; ADCIRC framework elevation component; description and examples of topographic features such as levees, roadways, railroads, etc. currently utilized in the mesh; ADCIRC model validation demonstration through historic event simulations; CERA demonstration), a breakout activity for participant groups to identify and discuss raised features not currently in the mesh and document them on provided worksheets, and a closing session for debriefing and discussion of future model improvements. Evaluation involved developing, and analyzing a

  19. Radar observations of a tornado-spawning storm complex in Southeast Brazil and Meso-Eta forecasts of this extreme event

    Science.gov (United States)

    Held, Gerhard; Gomes, Jorge Luis; Gomes, Ana Maria

    2014-05-01

    During the early afternoon of 22 September 2013, severe storms, accompanied by large hail, damaging winds, heavy precipitation and intense lightning activity, devastated a region in the southeast State of São Paulo. Several extremely intense storm cells moved at up to 80 km/h east-southeastwards, ahead of a strong cold front approaching through Paraná, which created extremely unstable conditions that led to deep convection and overshooting towers up to 18 km. At least one of theses cells spawned a tornado when it reached the town of Taquarituba. The tornado traversed the town from south-southwest to north-northeast and was responsible for 63 people injured and two fatalities. Based on the damage reported, it was at least an F3 according to the Fujita scale. The objective of the present study is to characterize this severe thunderstorm event, using different types of data, and to evaluate the forecasts provided by the Meso-Eta model centered over Bauru. The pre-frontal and frontal convective cells were tracked throughout their life-time by IPMet's Doppler radars, which cover the western and central regions of the State São Paulo, as well as northern Paraná State. Radar volume scans, generated every 7,5 min, were processed with the TITAN (Thunderstorm Identification, Tracking, Analysis and Nowcasting) Software, yielding the following preliminary results: as the storm complex traversed the Paranapanema River, which forms the border between the two states, the cells intensified drastically and shortly before reaching the town of Taquarituba, that particular cell displayed extremely strong radial shear just above the cloud base (about -20 to +35 m/s), which led to the formation of a deep meso-cyclone, from which the tornado spawned and touched down at around 14:30 LT (LT=UT-3h). Cell properties calculated by TITAN showed a drastic increase of VIL (Vertically Integrated Liquid water content) from 13:52 LT (7,9 kg/m2) to a maximum of 61,8 kg/m2 at 14:15 LT. From 14

  20. Difference in Pro-Inflammatory Cytokine Responses Induced in THP1 Cells by Particulate Matter Collected on Days with and without ASIAN Dust Storms

    Directory of Open Access Journals (Sweden)

    Masanari Watanabe

    2015-07-01

    Full Text Available The associations between particulate matter from Asian dust storms (ADS and health disorders differ among studies, and the underlying mechanisms remain unclear. In this study, ADS and non-ADS particles were tested for their potential to induce pro-inflammatory cytokines associated with adverse respiratory effects. Particulate matter was collected in Japan during four periods in 2013 (2 × ADS periods; 2 × non-ADS. THP1 cells were exposed to this particulate matter, and the levels of various interleukins (ILs, and tumor necrosis factor (TNF-α were measured. Levels of IL-2 increased significantly following exposure to all particulate matter samples (compared to levels in a solvent control. Increased levels of IL-10 and TNF-α were also observed following exposure to particles collected during three (one ADS and two non-ADS and two (one ADS and one non-ADS collection periods, respectively. Thus, the effects of particulate matter on cytokine responses differed according to collection period, and the effects of ADS particles differed for each ADS event. Additionally, the levels of pro-inflammatory cytokines induced by ADS particles were not always higher than those induced by non-ADS particles.

  1. DREAMS: a payload on-board the ExoMars EDM Schiaparelli for the characterization of Martian environment during the statistical dust storm season

    Science.gov (United States)

    Molfese, Cesare; Esposito, Francesca; Debei, Stefano; Bettanini, Carlo; Arruego Rodríguez, Ignacio; Colombatti, Giacomo; Harri, Ari-Matty.; Montmessin, Franck; Wilson, Colin; Aboudan, Alessio; Mugnuolo, Raffaele; Pirrotta, Simone; Marchetti, Ernesto; Witasse, Olivier

    2015-04-01

    , the dust opacity, and the atmospheric electric properties close to the surface of Mars. It will fly in January 2016 on-board the Schiaparelli Entry, Descent and landing Demonstrator Module (EDM) of the ExoMars space mission. It is foreseen to land on Mars in late October 2016 during the statistical dust storm season. Therefore, DREAMS might have the unique chance to make scientific measurements to characterize the Martian environment in a dusty scenario also performing the first ever measurements of atmospheric electric field on Mars. The relationship between the process of dust entrainment in the atmosphere during dust events and the enhancement of atmospheric electric field has been widely studied in an intense field test campaign in the Sahara desert. In order to better characterize this physical process, we performed atmospheric and environmental measurements comparable to those that DREAMS will acquire on Mars. Preliminary results will be discussed. DREAMS is in a high development state. A first model has been delivered to ESA and has been integrated in the EDM Flight Model. Integration tests are on-going. The DREAMS Flight Model will be delivered at the end of March this year.

  2. A 10,000 year record of dune activity, dust storms, and severe drought in the central Great Plains

    Science.gov (United States)

    Miao, Xiaodong; Mason, Joseph A.; Swinehart, James B.; Loope, David B.; Hanson, Paul R.; Goble, Ronald J.; Liu, Xiaodong

    2007-02-01

    Dune fields and loess deposits of the Great Plains of North America contain stratigraphic records of eolian activity that can be used to extend the short observational record of drought. We present a 10,000 yr reconstruction of dune activity and dust production in the central Great Plains region, based on 95 optically stimulated luminescence ages. The integration of data from both eolian sand and loess is an important new aspect of this record. Clusters of ages define episodes of extensive eolian activity, which we interpret as a response to frequent severe drought, at 1.0 0.7 ka and 2.3 4.5 ka (with peaks centered on 2.5 and 3.8 ka); sustained eolian activity occurred from 9.6 to 6.5 ka. Parts of this record may be consistent with hypotheses linking Holocene drought to sea surface temperature anomalies in the Pacific or Atlantic oceans, or to the El Niño-Southern Oscillation phenomenon, but the record as a whole is difficult to reconcile with any of these hypotheses.

  3. Machine learning methods for detection of dust from Meteosat imagery

    Science.gov (United States)

    Kolios, Stavros; Hatzianastassiou, Nikos

    2017-04-01

    Dust and sand storms can create potentially hazardous air quality conditions and adversely affect climate on a regional and world-wide scale, by modifying the shortwave and longwave radiation budgets, and human health. The indirect effects of dust are also significant because they modify cloud and precipitation properties and influence the general circulation of the atmosphere. In addition, consideration of dust has been shown to improve the weather forecast ability of models. For these reasons, there is an increasing and strong interest for real-time dust detection and monitoring as well as for dust load estimation from satellite observations, which offer the best solution to the problem. Indeed, remote sensing has been shown to be a valuable tool for detecting, mapping and forecasting dust events. Furthermore, dust satellite remote sensing is also useful in providing long-term and global observations of dust. Nevertheless, the majority of the approaches for dust detection and monitoring are still based on simple thresholding of the multispectral satellite imagery. This study is an effort to investigate the efficiency of machine learning techniques in order to accurately classify different cloud features in Meteosat imagery and detect dust in different atmospheric layers over the greater Mediterranean basin. More specifically, different Support Vector Machines (SVM) and Artificial Neural Network (ANN) schemes are tested to conclude on the most appropriate parameterization of the examined classification schemes. The training samples are collected after spatiotemporal correlation of AERONET station measurements with Meteosat images. Τhe efficiency of the examined algorithms is also tested using AERONET station data in selected cases. This study is first step toward the development of an integrated methodology for an accurate detection, monitoring and estimation of dust using exclusively satellite imagery.

  4. Sensitivity of WRF-chem predictions to dust source function specification in West Asia

    Science.gov (United States)

    Nabavi, Seyed Omid; Haimberger, Leopold; Samimi, Cyrus

    2017-02-01

    Dust storms tend to form in sparsely populated areas covered by only few observations. Dust source maps, known as source functions, are used in dust models to allocate a certain potential of dust release to each place. Recent research showed that the well known Ginoux source function (GSF), currently used in Weather Research and Forecasting Model coupled with Chemistry (WRF-chem), exhibits large errors over some regions in West Asia, particularly near the IRAQ/Syrian border. This study aims to improve the specification of this critical part of dust forecasts. A new source function based on multi-year analysis of satellite observations, called West Asia source function (WASF), is therefore proposed to raise the quality of WRF-chem predictions in the region. WASF has been implemented in three dust schemes of WRF-chem. Remotely sensed and ground-based observations have been used to verify the horizontal and vertical extent and location of simulated dust clouds. Results indicate that WRF-chem performance is significantly improved in many areas after the implementation of WASF. The modified runs (long term simulations over the summers 2008-2012, using nudging) have yielded an average increase of Spearman correlation between observed and forecast aerosol optical thickness by 12-16 percent points compared to control runs with standard source functions. They even outperform MACC and DREAM dust simulations over many dust source regions. However, the quality of the forecasts decreased with distance from sources, probably due to deficiencies in the transport and deposition characteristics of the forecast model in these areas.

  5. Delivery of Forecasted Atmospheric Ozone and Dust for the New Mexico Environmental Public Health Tracking System - An Open Source Geospatial Solution

    Science.gov (United States)

    Hudspeth, W. B.; Sanchez-Silva, R.; Cavner, J. A.

    2010-12-01

    New Mexico's Environmental Public Health Tracking System (EPHTS), funded by the Centers for Disease Control (CDC) Environmental Public Health Tracking Network (EPHTN), aims to improve health awareness and services by linking health effects data with levels and frequency of environmental exposure. As a public health decision-support system, EPHTS systems include: state-of-the-art statistical analysis tools; geospatial visualization tools; data discovery, extraction, and delivery tools; and environmental/public health linkage information. As part of its mandate, EPHTS issues public health advisories and forecasts of environmental conditions that have consequences for human health. Through a NASA-funded partnership between the University of New Mexico and the University of Arizona, NASA Earth Science results are fused into two existing models (the Dust Regional Atmospheric Model (DREAM) and the Community Multiscale Air Quality (CMAQ) model) in order to improve forecasts of atmospheric dust, ozone, and aerosols. The results and products derived from the outputs of these models are made available to an Open Source mapping component of the New Mexico EPHTS. In particular, these products are integrated into a Django content management system using GeoDjango, GeoAlchemy, and other OGC-compliant geospatial libraries written in the Python and C++ programming languages. Capabilities of the resultant mapping system include indicator-based thematic mapping, data delivery, and analytical capabilities. DREAM and CMAQ outputs can be inspected, via REST calls, through temporal and spatial subsetting of the atmospheric concentration data across analytical units employed by the public health community. This paper describes details of the architecture and integration of NASA Earth Science into the EPHTS decision-support system.

  6. Confidence in Coastal Forecasts

    NARCIS (Netherlands)

    Baart, F.

    2013-01-01

    This thesis answers the question "How can we show and improve our confidence in coastal forecasts?", by providing four examples of common coastal forecasts. The first example shows how to improve the estimate of the one in ten thousand year storm-surge level. The three dimensional reconstruction,

  7. Observation of atmospheric aerosols at Mt. Hua and Mt. Tai in central and east China during spring 2009 - Part 2: Impact of dust storm on organic aerosol composition and size distribution

    Science.gov (United States)

    Wang, G. H.; Li, J. J.; Cheng, C. L.; Zhou, B. H.; Xie, M. J.; Hu, S. Y.; Meng, J. J.; Sun, T.; Ren, Y. Q.; Cao, J. J.; Liu, S. X.; Zhang, T.; Zhao, Z. Z.

    2012-05-01

    PM10 and size-resolved particles (9-stage) were simultaneously collected at Mt. Hua and Mt. Tai in central and east China during the spring of 2009 including a massive dust storm occurring on 24 April (named as DS II), and determined for organic compounds to investigate the impact of dust storm on organic aerosols. High molecular weight (HMW) n-alkanes, fatty acids, and fatty alcohols and trehalose sharply increased and almost entirely stayed in coarse particles when dust storm was present, suggesting that high level of organic aerosols in the mountain atmospheres during the event largely originated from Gobi desert plants. However, most anthropogenic aerosols (e.g. PAHs, and aromatic and dicarboxylic acids) during the event significantly decreased due to a dilution effect, indicating that anthropogenic aerosols in the mountain atmospheres during the nonevent period largely originated from local/regional sources rather than from long-range transport. Trehalose, a metabolism product enriched in biota in dry conditions, was 62 ± 78 and 421 ± 181 ng m-3 at Mt. Hua and Mt. Tai during DS II, 10-30 times higher than that in the nonevent time, indicating that trehalose may be a tracer for dust emissions from Gobi desert regions. Molecular compositions of organic aerosols in the mountain samples demonstrate that domestic coal burning is still the major source of PAHs in China. n-Alkanes and fatty acids showed a bimodal size distribution during the nonevent with a major peak in fine mode (2.1 μm). The coarse mode significantly increased and even dominated over the whole size range when dust was present. Glucose and trehalose were also dominant in the coarse mode especially in the DS II time. PAHs and levoglucosan concentrated in fine particles with no significant changes in size distribution when dust storm occurred. However, phthalic and succinic acids showed bimodal size distribution pattern with an increase in coarse mode during the event, because both are formed via

  8. Exploring Dust Impacts on Tropical Systems from the NASA HS-3 Field Campaign

    Science.gov (United States)

    Nowottnick, Ed; Colarco, Pete; da Silva, Arlindo; Barahona, Donifan; Hlavka, Dennis

    2015-01-01

    One of the overall scientific goals of the NASA Hurricane and Severe Storm Sentinel (HS-3) field campaign is to better understand the role of the Saharan Air Layer (SAL) in tropical storm development. During the 2012 HS-3 deployment, the Cloud Physics Lidar (CPL) observed dust within SAL air in close proximity to a developing Nadine (September 11, 2012). Throughout the mission, the NASA GEOS-5 modeling system supported HS-3 by providing 0.25 degrees resolution 5-day global forecasts of aerosols, which were used to support mission planning. The aerosol module was radiatively interactive within the GEOS-5 model, but aerosols were not directly coupled to cloud and precipitation processes. In this study we revisit the aerosol forecasts with an updated version of the GEOS-5 model. For the duration of Hurricane Nadine, we run multiday climate simulations leading up to each respective Global Hawk flight with and without aerosol direct interaction. For each set of simulations, we compare simulated dust mass fluxes to identify differences in SAL entrainment related to the interaction between dust aerosols and the atmosphere. We find that the direct effects of dust induce a low level anticyclonic circulation that temporarily shields Nadine from the intrusion of dry air, leading to a more intense storm.

  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. Aerosol Radiative Forcing and Weather Forecasts in the ECMWF Model

    Science.gov (United States)

    Bozzo, A.; Benedetti, A.; Rodwell, M. J.; Bechtold, P.; Remy, S.

    2015-12-01

    Aerosols play an important role in the energy balance of the Earth system via direct scattering and absorpiton of short-wave and long-wave radiation and indirect interaction with clouds. Diabatic heating or cooling by aerosols can also modify the vertical stability of the atmosphere and influence weather pattern with potential impact on the skill of global weather prediction models. The Copernicus Atmosphere Monitoring Service (CAMS) provides operational daily analysis and forecast of aerosol optical depth (AOD) for five aerosol species using a prognostic model which is part of the Integrated Forecasting System of the European Centre for Medium-Range Weather Forecasts (ECMWF-IFS). The aerosol component was developed during the research project Monitoring Atmospheric Composition and Climate (MACC). Aerosols can have a large impact on the weather forecasts in case of large aerosol concentrations as found during dust storms or strong pollution events. However, due to its computational burden, prognostic aerosols are not yet feasible in the ECMWF operational weather forecasts, and monthly-mean climatological fields are used instead. We revised the aerosol climatology used in the operational ECMWF IFS with one derived from the MACC reanalysis. We analyse the impact of changes in the aerosol radiative effect on the mean model climate and in medium-range weather forecasts, also in comparison with prognostic aerosol fields. The new climatology differs from the previous one by Tegen et al 1997, both in the spatial distribution of the total AOD and the optical properties of each aerosol species. The radiative impact of these changes affects the model mean bias at various spatial and temporal scales. On one hand we report small impacts on measures of large-scale forecast skill but on the other hand details of the regional distribution of aerosol concentration have a large local impact. This is the case for the northern Indian Ocean where the radiative impact of the mineral

  11. The Storm in The Storm

    Institute of Scientific and Technical Information of China (English)

    王颖

    2015-01-01

    The Storm tells a story about sexual issues that two former lovers met in a stormy day and spent a short period of happy time together. In this story, the storm plays an important part,which is just like the thread that joins the plots together, both in natural storm and in feeling storm. It is the driving force behind the story and the affair. As the storm begins climaxes and ends so do the affair and the story. From the appearance, the storm has no harm. Actually, the storm in feeling is bad for the marriage, even in current times, so the story make people speculate the loyalty to the marriage.

  12. Evaluation of atmospheric dust prediction models using ground-based observations

    Science.gov (United States)

    Terradellas, Enric; María Baldasano, José; Cuevas, Emilio; Basart, Sara; Huneeus, Nicolás; Camino, Carlos; Dundar, Cinhan; Benincasa, Francesco

    2013-04-01

    An important step in numerical prediction of mineral dust is the model evaluation aimed to assess its performance to forecast the atmospheric dust content and to lead to new directions in model development and improvement. The first problem to address the evaluation is the scarcity of ground-based routine observations intended for dust monitoring. An alternative option would be the use of satellite products. They have the advantage of a large spatial coverage and a regular availability. However, they do have numerous drawbacks that make the quantitative retrievals of aerosol-related variables difficult and imprecise. This work presents the use of different ground-based observing systems for the evaluation of dust models in the Regional Center for Northern Africa, Middle East and Europe of the World Meteorological Organization (WMO) Sand and Dust Storm Warning Advisory and Assessment System (SDS-WAS). The dust optical depth at 550 nm forecast by different models is regularly compared with the AERONET measurements of Aerosol Optical Depth (AOD) for 40 selected stations. Photometric measurements are a powerful tool for remote sensing of the atmosphere allowing retrieval of aerosol properties, such as AOD. This variable integrates the contribution of different aerosol types, but may be complemented with spectral information that enables hypotheses about the nature of the particles. Comparison is restricted to cases with low Ångström exponent values in order to ensure that coarse mineral dust is the dominant aerosol type. Additionally to column dust load, it is important to evaluate dust surface concentration and dust vertical profiles. Air quality monitoring stations are the main source of data for the evaluation of surface concentration. However they are concentrated in populated and industrialized areas around the Mediterranean. In the present contribution, results of different models are compared with observations of PM10 from the Turkish air quality network for

  13. Effects of Storm Dust on Gas Exchange in Crop Leaves%沙尘暴粉尘对不同作物气体交换特征的影响

    Institute of Scientific and Technical Information of China (English)

    赵华军; 王立; 赵明; 杨自辉; 王强强

    2011-01-01

    The sand storm dust adheres to the crops’ leaves, has obvious negative influences to crops’ Pn,Tr,Gs and respiration, and even causes the crop output to drop finally.The paper presented gas exchanges on three traditional crops in Minqin.It mainly solved the dust capacity of leaves influence on respiration rate of different crops as well as the different period of duration, the different position of leaves to respiration influence.The results showed that(1)The rate of net photosynthetic rate(Pn),transpiration rate(Tr), stomatal conductance(Gs) of cotton were higher than other two species, indicating smaller loss rate of gas exchange parameters but higher adaptability to storm dust environment for wheat and corn; (2)Correlation analysis showed a remarkable negative correlation between rate of respiration rate and amount of dust detained;(3)The respiration rate with dust born leaves and clean leaves under different period and heights were extremely significant(P<0.01).%沙尘暴粉尘附着于作物叶片,对作物的光合作用、蒸腾作用、气孔导度及呼吸作用有明显的负面影响,并最终导致作物产量下降.通过对小麦、玉米和棉花3种民勤传统农作物的光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)和呼吸速率(R)的测定,主要研究不同滞尘量对不同作物呼吸强度的影响,同时探讨了沙尘暴粉尘对同一作物不同生育期、不同叶位叶片呼吸强度的影响.结果表明,(1)棉花的Pn、Tr、Gs与小麦、玉米的相比,下降幅度较大,即小麦和玉米对粉尘污染生境的适应能力较强,棉花较差;(2)3种作物叶片的呼吸强度都随叶片滞尘量的增加而降低,呈明显负相关关系;(3)在不同生育期,作物呼吸强度差异达极显著(P<0.01);不同叶位叶片的呼吸强度也存在显著性差异.

  14. Joint Typhoon Warning Center (JTWC) Storm Wallets

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Joint Typhoon Warning Center (JTWC) is responsible for typhoon forecasts and warnings for the Western Pacific and Indian Ocean basins. After each storm, the JTWC...

  15. 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.

  16. Forecasting the space weather impact

    DEFF Research Database (Denmark)

    Crosby, N. B.; Veronig, A.; Robbrecht, E.

    2012-01-01

    The FP7 COronal Mass Ejections and Solar Energetic Particles (COMESEP) project is developing tools for forecasting geomagnetic storms and solar energetic particle (SEP) radiation storms. By analysis of historical data, complemented by the extensive data coverage of solar cycle 23, the key ingredi...

  17. A framework for high-resolution global forecasts of the impacts of climatic and land use changes on Earth surface processes

    Science.gov (United States)

    Pelletier, J. D.; Russell, J. L.; McGuire, L.

    2016-12-01

    The Earth System Modeling (ESM) community has been very effective at forecasting primary climatic and land-use change forcing variables, but "downstream" scientific communities (principally hydrologists, ecologists, and geomorphologists) have arguably been less effective at translating available ESM-derived forecasts into assessments of the changes that are likely to occur in the rates of Earth surface processes and the probabilities of Earth surface hazards including floods, debris flows, soil erosion, and dust storms. In this talk I propose a framework for forecasting changes in surface process rates and natural hazard probabilities. This framework uses global, gridded reanalysis data (1980-present) for primary climatic and land use change forcing variables (e.g., precipitation, soil moisture, land cover, and wind speed) to calibrate and validate geomorphic models that are applied globally within a High Performance Computing (HPC) environment. Ensemble ESM forecasts (from the present to 2100) of primary climatic and land use change forcing variables are then used to forecast changes in the rates of geomorphic processes and hazard probabilities. We demonstrate this framework using wind erosion and dust storms as examples. However, the framework is general and is designed for application to a wide variety of geomorphic processes and hazards. We address the challenges with this approach, such as downscaling reanalysis and ESM model output to the scales necessary to resolve the spatial and temporal variations in the driving and resisting forces necessary for accurate forecasts. We also address the variability among forecasts obtained using different ESM model forecasts. The results highlight the nonlinear, threshold nature of many geomorphic processes and hazards and the resulting sensitivity of forecasts to differences in ESM forecasts of the primary climatic and land use change variables.

  18. Dust, Climate, and Human Health

    Science.gov (United States)

    Maynard, N. G.

    2003-12-01

    Air pollution from both natural and anthropogenic causes is considered to be one of the most serious world-wide environment-related health problems, and is expected to become worse with changes in the global climate. Dust storms from the atmospheric transport of desert soil dust that has been lifted and carried by the winds - often over significant distances - have become an increasingly important emerging air quality issue for many populations. Recent studies have shown that the dust storms can cause significant health impacts from the dust itself as well as the accompanying pollutants, pesticides, metals, salt, plant debris, and other inorganic and organic materials, including viable microorganisms (bacteria, viruses and fungi). For example, thousands of tons of Asian desert sediments, some containing pesticides and herbicides from farming regions, are commonly transported into the Arctic during dust storm events. These chemicals have been identified in animal and human tissues among Arctic indigenous populations. Millions of tons of airborne desert dust are being tracked by satellite imagery, which clearly shows the magnitude as well as the temporal and spatial variability of dust storms across the "dust belt" regions of North Africa, the Middle East, and China. This paper summarizes the most recent findings on the effects of airborne desert dust on human health as well as potential climate influences on dust and health

  19. Assimilating MODIS Aerosol Optical Depth Observations to Assess the Impact of Saharan Mineral Dust on the Genesis and Evolution of Hurricane Ernesto (2006)

    Science.gov (United States)

    Earl, K. S.; Chen, S. H.; Liu, Z.; Lin, H. C.

    2016-12-01

    Mineral dust can impact the atmosphere in two primary ways: (1) by directly absorbing, scattering, and emitting short and longwave radiation (radiative effects), and (2) by acting as cloud condensation or ice nuclei, indirectly affecting cloud optical and physical properties as well as precipitation processes (microphysical effects). During boreal summer, mineral dust plumes from North Africa are advected well into the tropical North Atlantic and can regularly be found in close proximity to tropical cyclones (TCs) or their seed disturbances, particularly in the Atlantic Main Development Region, potentially affecting their development and evolution. Many studies indicate that dust radiative effects within African dust plumes alter vertical and horizontal temperature gradients in such a way that may increase mid-level wind shear and static stability in the tropical Atlantic, possibly altering TC development and/or track. The effects of dust microphysics on TCs, on the other hand, are less certain but an increasing body of research suggests that they depend on TC strength, environmental conditions, and how close dust aerosols are to the storm center. Hurricane Ernesto (2006), whose precursor African Easterly Wave disturbance traveled across the Atlantic in close association with a large, persistent dust plume, is one such storm whose development may have been greatly influenced by dust physical processes. The storm developed only after the eventual dissipation of the plume in the eastern Caribbean. In this study, we examine the impact of mineral dust on the genesis and evolution of Hurricane Ernesto with a series of numerical experiments using a modified, dust-capable version of the WRF model and analyses created by assimilating meteorological and MODIS AOD observations within the GSI 3DVAR software framework. The impacts of MODIS AOD assimilation on the simulated dust distribution and forecasts of Ernesto's development are highlighted.

  20. Impact of dust aerosols on Hurricane Helene's early development through the deliquescent heterogeneous freezing mode

    Directory of Open Access Journals (Sweden)

    H. Zhang

    2011-05-01

    Full Text Available An ice nucleation parameterization accounting for the deliquescent heterogeneous freezing (DHF mode was implemented into the Weather Research Forecast (WRF model. The DHF mode refers to the freezing process for internally mixed aerosols with soluble and insoluble species that can serve as both cloud condensation nuclei (CCN and ice nuclei (IN, such as dust. A modified version of WRF was used to examine the effect of Saharan dust on the early development of Hurricane Helene (2006 via acting as CCN and IN. The WRF simulations showed the tendency of DHF mode to promote ice formation at lower altitudes in strong updraft cores, increase the local latent heat release, and produce more low clouds and less high clouds. The inclusion of dust acting as CCN and IN through the DHF mode modified the storm intensity, track, hydrometeor distribution, cloud top temperature (hence the storm radiative energy budget, and precipitation and latent heat distribution. However, changes in storm intensity, latent heating rate, and total precipitation exhibit nonlinear dependence on the dust concentration. Improvement in the representation of atmospheric aerosols and cloud microphysics has the potential to contribute to better prediction of tropical cyclone development.

  1. Is It Going to Rain Today? Understanding the Weather Forecast.

    Science.gov (United States)

    Allsopp, Jim; And Others

    1996-01-01

    Presents a resource for science teachers to develop a better understanding of weather forecasts, including outlooks, watches, warnings, advisories, severe local storms, winter storms, floods, hurricanes, nonprecipitation hazards, precipitation probabilities, sky condition, and UV index. (MKR)

  2. Dust Propagation and Radiation In the Presence of a Low-level Jet in Central China on March 17, 2010

    Science.gov (United States)

    McDowell, B. K.; Chen, S. H.

    2014-12-01

    Suspended dust in the air can directly change the energy budget in the atmosphere and at the surface through scattering and absorption of radiation. Thus, dust can potentially modify the development of weather systems. To explore the dust-radiation effects on weather systems, a dust model was developed based on the Weather Research and Forecasting (WRF) model. The calculations of dust processes in the WRF dust model include emission, advection, boundary layer mixing, cumulus mixing, dust-radiation interaction, wet scavenging, and sedimentation. Due to a high vertical spatial resolution near the surface a time splitting method was applied to the calculation of dust sedimentation to relax the numerical time step. The "Hexi Corridor" is the historical name given to a string of oases along the northern slope of the Tibetan Plateau that formed a relatively easy transportation route between eastern China and central Asia. As trade developed over the centuries, this route became known as the Silk Road. This corridor also marks the transition from the relatively flat Gobi desert area in northern China to the elevated mountains of the Tibetan Plateau. These mountains present a southern barrier to the paths of dust storms that develop during spring outbreaks of the Mongolian Cyclone. In March of 2010, a series of dust storms developed in the Gobi Desert north of the Hexi Corridor that transported massive amounts of dust eastward to central and northeastern China, Korea and Japan. On March 17 during this event, a low-level jet developed along the northern perimeter of the Plateau, in alignment with upper level winds and the Hexi Corridor. Over the course of the day, a well-defined short-duration dust plume was emitted in the southern Gobi desert area and was transported over 1300 km in a southeast direction, over the Loess Plateau and into the Gansu Province. In this study, the interactions of synoptic conditions with regional topography that led to the development of the low

  3. CFORS - Regional Chemical and Weather Forecast System in Support of Field Experiments

    Science.gov (United States)

    Yienger, J. J.; Uno, I.; Guttikunda, S. K.; Carmichael, G. R.; Tang, Y.; Thongboonchoo, N.; Woo, J.; Dorwart, J.; Streets, D.

    2001-12-01

    In this paper we will present the development, evaluation, and use of improved modeling techniques and methodologies for the integration of meteorological forecasts with air pollution forecasts in support of field operations during the TRACE-P and Ace-Asia experiments in East Asia. During the campaign period we provided a variety of forecast products using our regional modeling system built upon the dynamic meteorological model RAMS and the 3-D regional chemical transport models STEM-III. These models were run in both on-line and off-line modes, and the results integrated into an interactive web-based data mining and analysis framework. This resulting Chemical Weather Forecasting System CFORS, was run operationally for the period February through May 2001, and provided 72-hr forecasts of a variety of aerosol, chemical and air mass and emission marker quantities. These included aerosol mass distribution and optical depth by major component (e.g., dust, sea salt, black carbon, organic carbon, and sulfate), photochemical quantities including ozone and OH/HO2, and air mass & emissions markers including lightning, volcanic, mega-cities, and biomass burning. These model products were presented along with meteorological forecasts and satellite products, and used to help determine the flight plans, the positioning of the ship, and to alert surface stations of upcoming events (such as dust storms). The use of CFORS forecasts (along with other model results) models were shown to provide important new information and level of detail into mission planning. For example many of the mission objectives required designing flight paths that sampled across gradients of optical depth, or flew above, below and through vertical layers of aerosol, intercepted biomass emission plumes, or sampled dust storms. CFORS, forecasts of dust outbreaks and plume locations, etc., proved to be very useful in designing missions that meet these objective. In this paper we will present an overview of

  4. Aeolian sediments deposited in Lake Hamoun; the proxy of frequency and severity of dust storms in Sistan since the late glacial

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Hamzeh

    2017-03-01

    Our results suggest that the late Holocene in the Sistan Basin (facies C3 was characterized by frequent changes in MLW and SH activity. Palaeoclimatic records show since the mid Holocene to the present time, the climate of Sistan and its catchment area more or less oscillated around a steady state comparable with modern situations (Hamzeh et al. 2016. During this time, the hydroclimatic regime and Aeolian activity of the Sistan Basin and NW Himalaya have been mostly governed by MLW-associated precipitation. Periods of prolonged droughts are indicated in proxy records of NW Iran such Lake Neor (Sharifi et al. 2015, presumably consistent with high MS values in our record. It is possible that weakening of ISM, along with distal influences of the MLW during the late Holocene exposed the Lake Hamoun basin to frequent droughts. Frequent lake level fluctuations show unstable climate of the Sistan Basin during mid to late Holocene with frequent wind storms.

  5. Operational Dust Prediction

    Science.gov (United States)

    Benedetti, Angela; Baldasano, Jose M.; Basart, Sara; Benincasa, Francesco; Boucher, Olivier; Brooks, Malcolm E.; Chen, Jen-Ping; Colarco, Peter R.; Gong, Sunlin; Huneeus, Nicolas; Jones, Luke; Lu, Sarah; Menut, Laurent; Morcrette, Jean-Jacques; Mulcahy, Jane; Nickovic, Slobodan; Garcia-Pando, Carlos P.; Reid, Jeffrey S.; Sekiyama, Thomas T.; Tanaka, Taichu Y.; Terradellas, Enric; Westphal, Douglas L.; Zhang, Xiao-Ye; Zhou, Chun-Hong

    2014-01-01

    Over the last few years, numerical prediction of dust aerosol concentration has become prominent at several research and operational weather centres due to growing interest from diverse stakeholders, such as solar energy plant managers, health professionals, aviation and military authorities and policymakers. Dust prediction in numerical weather prediction-type models faces a number of challenges owing to the complexity of the system. At the centre of the problem is the vast range of scales required to fully account for all of the physical processes related to dust. Another limiting factor is the paucity of suitable dust observations available for model, evaluation and assimilation. This chapter discusses in detail numerical prediction of dust with examples from systems that are currently providing dust forecasts in near real-time or are part of international efforts to establish daily provision of dust forecasts based on multi-model ensembles. The various models are introduced and described along with an overview on the importance of dust prediction activities and a historical perspective. Assimilation and evaluation aspects in dust prediction are also discussed.

  6. Observing storm surges from satellite altimetry

    Science.gov (United States)

    Han, Guoqi

    2016-07-01

    Storm surges can cause catastrophic damage to properties and loss of life in coastal communities. Thus it is important to enhance our capabilities of observing and forecasting storm surges for mitigating damage and loss. In this presentation we show examples of observing storm surges around the world using nadir satellite altimetry, during Hurricane Sandy, Igor, and Isaac, as well as other cyclone events. The satellite observations are evaluated against tide-gauge observations and discussed for dynamic mechanisms. We also show the potential of a new wide-swath altimetry mission, the Surface Water and Ocean Topography (SWOT), for observing storm surges.

  7. Elemental tracers for Chinese source dust

    Institute of Scientific and Technical Information of China (English)

    张小曳; 张光宇; 朱光华; 张德二; 安芷生; 陈拓; 黄湘萍

    1996-01-01

    The mass-particle size distributions of 10 dust-carrying elements in aerosol particles were determined tor 12 sites in desert regions of northern China. The desert dust is proved to he of origin of eolian loess deposited on the Loess Plateau. Their transport to the loess was mainly attributable to the non-dust storm processes under the interglacial climate condition. The impact ot" dust storm on the accumulation of the loess increased in the glacial stage. On the basis of the signatures of 4 dust elements (Al. Fe, Mg and Sc). Chinese dust is believed to have 3 major desert sources (northwestern deserts, northern high dust deserts and northern low dust deserts). With a chemical element balance model, an elemental tracer system is established to proportion the export of China-source dust.

  8. Investigations of Desert Dust and Smoke in the North Atlantic in Support of the TOMS Instrument

    Science.gov (United States)

    Toon, Owen B.

    2005-01-01

    During the initial period of the work we concentrated on Saharan dust storms and published a sequence of papers (Colarco et a1 2002,2003a,b, Toon, 2004). The U.S. Air Force liked the dust model so well that they appropriated it for operational dust storm forecasting (Barnum et al., 2004). The Air Force has used it for about 5 yrs in the Middle East where dust storms cause significant operational problems. The student working on this project, Peter Colarco, has graduated and is now a civil servant at Goddard where he continues to interact with the TOMS team. This work helped constrain the optical properties of dust at TOMS wavelengths, which is useful for climate simulations and for TOMS retrievals of dust properties such as optical depth. We also used TOMS data to constrain the sources of dust in Africa and the Middle East, to determine the actual paths taken by Saharan dust storms, to learn more about the mechanics of variations in the optical depths, and to learn more about the mechanisms controlling the altitudes of the dust. During the last two years we have been working on smoke from fires. Black carbon aerosols are one of the leading factors in radiative forcing. The US Climate Change Science Program calls this area out for specific study. It has been suggested by Jim Hansen, and Mark Jacobsen among others, that by controlling emissions of black carbon we might reduce greenhouse radiative forcing in a relatively painless manner. However, we need a greatly improved understanding of the amount of black carbon in the atmosphere, where it is located, where it comes from, how it is mixed with other particles, what its actual optical properties are, and how it evolves. In order to learn about these issues we are using a numerical model of smoke. We have applied this model to the SAFARI field program data, and used the TOMS satellite observations in that period (Sept. 2000). Our goal is to constrain source function estimates for black carbon, and smoke optical

  9. Impact of improved soil climatology and intialization on WRF-chem dust simulations over West Asia

    Science.gov (United States)

    Omid Nabavi, Seyed; Haimberger, Leopold; Samimi, Cyrus

    2016-04-01

    Meteorological forecast models such as WRF-chem are designed to forecast not only standard atmospheric parameters but also aerosol, particularly mineral dust concentrations. It has therefore become an important tool for the prediction of dust storms in West Asia where dust storms have the considerable impact on living conditions. However, verification of forecasts against satellite data indicates only moderate skill in prediction of such events. Earlier studies have already indicated that the erosion factor, land use classification, soil moisture, and temperature initializations play a critical role in the accuracy of WRF-chem dust simulations. In the standard setting the erosion factor and land use classification are based on topographic variations and post-processed images of the advanced very high-resolution radiometer (AVHRR) during the period April 1992-March 1993. Furthermore, WRF-chem is normally initialized by the soil moisture and temperature of Final Analysis (FNL) model on 1.0x1.0 degree grids. In this study, we have changed boundary initial conditions so that they better represent current changing environmental conditions. To do so, land use (only bare soil class) and the erosion factor were both modified using information from MODIS deep blue AOD (Aerosol Optical Depth). In this method, bare soils are where the relative frequency of dust occurrence (deep blue AOD > 0.5) is more than one-third of a given month. Subsequently, the erosion factor, limited within the bare soil class, is determined by the monthly frequency of dust occurrence ranging from 0.3 to 1. It is worth to mention, that 50 percent of calculated erosion factor is afterward assigned to sand class while silt and clay classes each gain 25 percent of it. Soil moisture and temperature from the Global Land Data Assimilation System (GLDAS) were utilized to provide these initializations in higher resolution of 0.25 degree than in the standard setting. Modified and control simulations were

  10. Dust transport into Martian polar latitudes

    Science.gov (United States)

    Murphy, J. R.; Pollack, J. B.

    1992-01-01

    The presence of suspended dust in the Martian atmosphere, and its return to the planet's surface, is implicated in the formation of the polar layered terrain and the dichotomy in perennial CO2 polar cap retention in the two hemispheres. A three dimensional model was used to study Martian global dust storms. The model accounts for the interactive feedbacks between the atmospheric thermal and dynamical states and an evolving radiatively active suspended dust load. Results from dust storm experiments, as well as from simulations in which there is interest in identifying the conditions under which surface dust lifting occurs at various locations and times, indicate that dust transport due to atmospheric eddy motions is likely to be important in the arrival of suspended dust at polar latitudes. The layered terrain in both polar regions of Mars is interpreted as the reality of cyclical episodes of volatile (CO2, H2O) and dust deposition.

  11. Study on Hail Weather Analysis and Forecast in Guilin

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The hail weather and forecast storm in Guilin were studied. [Method] In allusion to the occurrence of hailstorm in Guilin and considering the observation data of a new generation of Doppler weather radar in Guilin, the weather situation and radar echo characteristics in Guilin was summarized so as to explore the short time forecast method. [Result] There were one or two icy storms every year in Guilin. The occurrence of icy storm was distinctly influenced by terrain. A new generation of Doppler ...

  12. The Relationship between Decadal Variation of Sand-Dust Storm in North China and Decadal Variability of North Atlantic Air-Sea System%我国北方沙尘暴年代际变化与北大西洋海气系统年代际变率的联系

    Institute of Scientific and Technical Information of China (English)

    李耀辉; 孙国武; 张良; 段海霞

    2011-01-01

    In this paper, the characteristics between the decadal variation of sand-storm in north China and decadal variability of thermohaline circulation (THC) in recent 50 years are analyzed. It is found that there are some relationships between the sand-dust storm and THC. Further analyses indicate the primary process of this following relationship: THC influences on NAO, NAO on Siberia high, Siberia high on cold air activities, and then, on the sand-dust storm. The results show that when THC is strong (weak) , NAO is weak ( strong) , Siberia and north winds in surface are strong (weak), sand-dust storms are more (less). Moreover, a remarkable variation from the end of the 1970' s to the beginning of 1980' s is also found that THC, Siberia high and north wind changed from strong to weak, NAO from weak to strong and sand-dust storm in north China obviously decreased.%分析了近50年我国北方沙尘暴的年代际变化和热盐环流(THC)的年代际变率的演变特征,发现沙尘暴与THC存在一定的联系.这种相互联系的演变过程大致是:THC与北大西洋涛动(NAO)有联系,NAO与西伯利亚冷高压有联系,而西伯利亚高压又影响北半球冷空气活动,最终影响我国北方沙尘暴的发生.结果表明,THC强(弱)→NAO弱(强)→西伯利亚高压强(弱)→地面偏北风强(弱)→沙尘暴偏多(少).而且,在20世纪70年代末到80年代初,均存在一个明显的转折变化,即THC、西伯利亚高压和地面北风从强到弱,NAO从弱到强,沙尘暴则出现由偏多到偏少的变化趋势.

  13. How much North African dust emission is associated with breakdowns of nocturnal low-level jets?

    Science.gov (United States)

    Fiedler, S.; Schepanski, K.; Heinold, B.; Knippertz, P.; Tegen, I.

    2013-12-01

    Mineral dust aerosol has important impacts on atmospheric radiation transfer, optical properties and precipitability of clouds, as well as human health and eco-systems. Time, location and amount of dust emission are key factors for simulating the atmospheric life cycle of dust and its effects accurately. Dust emission is a non-linear function of surface properties, and the momentum transfer from the atmosphere to the Earth's surface. A phenomenon capable of mobilizing dust is the Nocturnal Low-Level Jet (NLLJ), a wind speed maximum at night caused by air accelerating due to reduced dynamical friction in the nocturnal boundary layer. Momentum from the NLLJ is transferred downwards by turbulence, predominantly during the following morning when surface heating erodes the nocturnal temperature inversion. While this breakdown of NLLJs has been suggested to be a main driver for dust storms in North Africa, a quantitative investigation based on analysis data is lacking. As part of the European Research Council funded 'Desert Storms' project, this work presents the first statistical analysis of the importance of NLLJs for the mineral dust amount emitted in North Africa. A new automated detection algorithm for NLLJs has been developed for analyzing the spatio-temporal characteristics and associated mineral dust emission amounts. The algorithm is applied to the European Centre for Medium-Range Weather Forecasts ERA-Interim re-analysis for 1979-2010. Near-surface wind speed and soil moisture from ERA-interim drive an off-line dust model for calculating associated dust emission fluxes. Annually and spatially averaged, NLLJs form in 29 % of the nights in North Africa. The areal distribution of NLLJs highlights their frequent occurrence along the margins of the Saharan heat-low in summer, and in regions affected by mountain channeling like the Bodélé Depression, Chad, predominantly in winter. In these seasonally varying hotspots NLLJs are identified in 40-80 % of the nights

  14. Investigating Massive Dust Events Using a Coupled Weather-Chemistry Model

    Science.gov (United States)

    Raman, A.; Arellano, A. F.

    2012-12-01

    Prediction of local to regional scale dust events is challenging due to the complex nature of key processes driving emission, transport, and deposition of mineral dust. In particular, it is difficult to map precisely the sources of mineral dust across heterogeneous land surface properties and land-use changes. This is especially true for Arizona haboobs. These dust storm events are typically driven by thunderstorms and down-bursts over arid regions generating high atmospheric loading of dust in the order of hundreds to thousands of microgram per cubic meter. Modeling and prediction of these events are further complicated by the limitations in satellite-derived and in-situ measurements of dust and related geophysical variables. Here, we investigate the capability of a coupled weather-chemistry model in predicting Arizona haboobs. In particular, this research focuses on the simulation of July 5, 2011 Phoenix haboob using Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) and Goddard Chemistry Aerosol Radiation and Transport Model (GOCART) dust scheme. We evaluate the ability of WRF-Chem in simulating the haboob using satellite retrievals of aerosol extinction properties and mass concentrations from Moderate Resolution Imaging Spectroradiometer (MODIS), Cloud-Aerosol Lidar and Infrared Pathfinder Satellite (CALIPSO) and high resolution SEVIRI false color dust product, in conjunction with in-situ PM10 and PM2.5 measurements. The study uses a nested modeling domain covering Utah, California and Arizona at a horizontal resolution of 5.4 km (outer) and 1.8 km (inner). Boundary conditions for the model are obtained from NOAA Global Forecasting System six-hourly forecast. We present results illustrating the key features of the haboobs, such as the cold pools and surface wind speeds driving the horizontal and vertical structure of the dust, as well as the patterns of dust transport and deposition. Although the spatio-temporal patterns of the haboob

  15. 3-D Storm Automatic Identification Based on Mathematical Morphology

    Institute of Scientific and Technical Information of China (English)

    HAN Lei; ZHENG Yongguang; WANG Hongqing; LIN Yinjing

    2009-01-01

    The strom identification, tracking, and forecasting method is one of the important nowcasting techniques. Accurate storm identification is a prerequisite for successful storm tracking and forecasting. Storm identi-fication faces two difficulties: one is false merger and the other is failure to isolate adjacent storms within a cluster of storms. The TITAN (Thunderstorm Identification, Tracking, Analysis, and Nowcasting) algo-rithm is apt to identify adjacent storm cells as one storm because it uses a single refiectivity threshold. The SCIT (Storm Cell Identification and Tracking) algorithm uses seven reflectivity thresholds and therefore is capable of isolating adjacent storm cells, but it discards the results identified by the lower threshold, leading to the loss of the internal structure information of storms. Both TITAN and SCIT have the problem of failing to satisfactorily identify false merger. To overcome these shortcomings, this paper proposes a novel approach based on mathematical morphology. The approach first applies the single threshold identification followed by implementing an erosion process to mitigate the false merger problem. During multi-threshold identification stages, dilation operation is performed against the storm cells which are just obtained by the higher threshold identification, until the storm edges touch each other or touch the edges of the previous storms identified by the lower threshold. The results of experiment show that by combining the strengths of the dilation and erosion operations, this approach is able to mitigate the false merger problem as well as maintain the internal structure of sub-storms when isolating storms within a cluster of storms.

  16. Emission, transport, and radiative effects of mineral dust from the Taklimakan and Gobi deserts: comparison of measurements and model results

    Science.gov (United States)

    Chen, Siyu; Huang, Jianping; Kang, Litai; Wang, Hao; Ma, Xiaojun; He, Yongli; Yuan, Tiangang; Yang, Ben; Huang, Zhongwei; Zhang, Guolong

    2017-02-01

    The Weather Research and Forecasting Model with chemistry (WRF-Chem model) was used to investigate a typical dust storm event that occurred from 18 to 23 March 2010 and swept across almost all of China, Japan, and Korea. The spatial and temporal variations in dust aerosols and the meteorological conditions over East Asia were well reproduced by the WRF-Chem model. The simulation results were used to further investigate the details of processes related to dust emission, long-range transport, and radiative effects of dust aerosols over the Taklimakan Desert (TD) and Gobi Desert (GD). The results indicated that weather conditions, topography, and surface types in dust source regions may influence dust emission, uplift height, and transport at the regional scale. The GD was located in the warm zone in advance of the cold front in this case. Rapidly warming surface temperatures and cold air advection at high levels caused strong instability in the atmosphere, which strengthened the downward momentum transported from the middle and low troposphere and caused strong surface winds. Moreover, the GD is located in a relatively flat, high-altitude region influenced by the confluence of the northern and southern westerly jets. Therefore, the GD dust particles were easily lofted to 4 km and were the primary contributor to the dust concentration over East Asia. In the dust budget analysis, the dust emission flux over the TD was 27.2 ± 4.1 µg m-2 s-1, which was similar to that over the GD (29 ± 3.6 µg m-2 s-1). However, the transport contribution of the TD dust (up to 0.8 ton d-1) to the dust sink was much smaller than that of the GD dust (up to 3.7 ton d-1) because of the complex terrain and the prevailing wind in the TD. Notably, a small amount of the TD dust (PM2.5 dust concentration of approximately 8.7 µg m-3) was lofted to above 5 km and transported over greater distances under the influence of the westerly jets. Moreover, the direct radiative forcing induced by dust

  17. Dust Devil Days

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Released 6 July 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth. Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms. Dust devils, small cyclonic wind storms, are common in the American Southwest and on Mars. As the dust devil moves across the surface it picks up the loose dust, leaving behind a dark track to mark its passage. These dust devil tracks are in the Argyre Basin. Image information: VIS instrument. Latitude -46.6, Longitude 317.5 East (42.5 West). 19 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the

  18. Regional characteristics of dust events in China

    Institute of Scientific and Technical Information of China (English)

    WANGShigong; WANGJinyan; ZHOUZijiang; SHANGKezheng; YANGDebao; ZHAO

    2003-01-01

    The regional characteristics of dust events in China has been mainly studied by using the data of dust storm,wind-blown sand and floating dust from 338 observation stations through China from 1954 to 2000.The results of this study are as follows:(1)In China,there are two high frequent areas of dust events,one is located in the area of Minfeng and Hotan in the South xinjiang Basin,the other is situated in the area of Minqin and Jilantai in the Hexi Region.Furthermore,the spatial distributions of the various types of dust events are different.The dust storms mainly occur in the arid and semiarid areas covering the deserts and the areas undergoing desertification in northern China.Wind-blown sand and floating-dust not only occur in the areas where dust storms occur,but also extend to the neighboring areas.The range of wind-blown sand extends northeastward and southeastward,but floating-dust mainly extends southeastward to the low-latitude region such as the East China Plain and the area of the middloe and lower reaches of the Yangtze River.Compared with wind-blown sand,the floating-dust seldom occurs in the high latitude areas such as North xinjiang and Northeast China.(2)The affected areas of dust storms can be divided into seven sub-regions,that is,North Xinjiang Region,South Xinjiang Region,Hexi Region,Qaidam Basin Region,Hetao Region.Northeastem China Region and Qinghai-Xizang (Tibet) Region.The area of the most frequent occurrence of dust storms and floating-dust is in South Xinjiang Region,and of wind-blown sang in the Hexi Region.In general,the frequency of dust events in all the seven regions shows a decreasing thendency from 1954 to 2000,but there are certain differences between various dust events in different regions.The maximum interannual change and ariance of dust events during this time happened in South Xinjiang Region and Hexi Region.The udst events generally occur most frequently in April in most parts of China.The spring occurred days of dust events

  19. Direct Radiative Effect of Mineral Dust on the Development of African Easterly Wave in Late Summer, 2003-2007

    Science.gov (United States)

    Ma, Po-Lun; Zhang, Kai; Shi, Jainn Jong; Matsui, Toshihisa; Arking, Albert

    2012-01-01

    Episodic events of both Saharan dust outbreaks and African Easterly Waves (AEWs) are observed to move westward over the eastern tropical Atlantic Ocean. The relationship between the warm, dry, and dusty Saharan Air Layer (SAL) on the nearby storms has been the subject of considerable debate. In this study, the Weather Research and Forecasting (WRF) model is used to investigate the radiative effect of dust on the development of AEWs during August and September, the months of maximum tropical cyclone activity, in years 2003-2007. The simulations show that dust radiative forcing enhances the convective instability of the environment. As a result, most AEWs intensify in the presence of a dust layer. The Lorenz energy cycle analysis reveals that the dust radiative forcing enhances the condensational heating, which elevates the zonal and eddy available potential energy. In turn, available potential energy is effectively converted to eddy kinetic energy, in which local convective overturning plays the primary role. The magnitude of the intensification effect depends on the initial environmental conditions, including moisture, baroclinity, and the depth of the boundary layer. We conclude that dust radiative forcing, albeit small, serves as a catalyst to promote local convection that facilitates AEW development.

  20. Storm surge model based on variational data assimilation method

    Institute of Scientific and Technical Information of China (English)

    Shi-li HUANG; Jian XU; De-guan WANG; Dong-yan LU

    2010-01-01

    By combining computation and observation information,the variational data assimilation method has the ability to eliminate errors caused by the uncertainty of parameters in practical forecasting.It was applied to a storm surge model based on unstructured grids with high spatial resolution meant for improving the forecasting accuracy of the storm surge.By controlling the wind stress drag coefficient,the variation-based model was developed and validated through data assimilation tests in an actual storm surge induced by a typhoon.In the data assimilation tests,the model accurately identified the wind stress drag coefficient and obtained results close to the true state.Then,the actual storm surge induced by Typhoon 0515 was forecast by the developed model,and the results demonstrate its efficiency in practical application.

  1. Forecast Forecasts the Trend

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The latest release of "2009 China Luxury Forecast" shows that while the financial crisis is leading a general decline in demand for luxury brands in Europe,America and Japan,the global economic downturn has had limited impact on Chinese luxury consumption and that there is widespread confidence in the future among Chinese luxury consumers.

  2. Forecast Forecasts the Trend

    Institute of Scientific and Technical Information of China (English)

    Wang Ting

    2009-01-01

    @@ The latest release of "2009 China Luxury Forecast" shows that while the financial crisis is leading a general decline in demand for luxury brands in Europe,America and Japan,the global economic downturn has had limited impact on Chinese luxury consumption and that there is widespread confidence in the future among Chinese luxury consumers.

  3. 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...

  4. Validation of aerosols, reactive gases and greenhouse gases in the CAMS forecasts, analyses and reanalyses

    Science.gov (United States)

    Eskes, Henk; Basart, Sara; Blechschmidt, Anne; Chabrillat, Simon; Clark, Hannah; Cuevas, Emilio; Engelen, Richard; Kapsomenakis, John; Katragkou, Eleni; Mantzius Hansen, Kaj; Niemeijer, Sander; Ramonet, Michel; Schulz, Michael; Sudarchikova, Natalia; Wagner, Annette; Warneke, Thorsten

    2016-04-01

    The Atmosphere Monitoring Service of the European Copernicus Programme (CAMS) is an operational service providing analyses, reanalyses and daily forecasts of aerosols, reactive gases and greenhouse gases on a global scale, and air quality forecasts and reanalyses on a regional scale. CAMS is based on the systems developed during the European MACC I-II-III (Monitoring Atmospheric Composition and Climate) research projects. In CAMS data assimilation techniques are applied to combine in-situ and remote sensing observations with global and European-scale models of atmospheric reactive gases, aerosols and greenhouse gases. The global component is based on the Integrated Forecast System of the ECMWF, and the regional component on an ensemble of 7 European air quality models. CAMS is implemented by ECMWF, and the transition from MACC to CAMS is currently being implemented (2015-2016). CAMS has a dedicated validation activity, a partnership of 13 institutes co-ordinated by KNMI, to document the quality of the atmospheric composition products. In our contribution we discuss this validation activity, including the measurement data sets, validation requirements, the operational aspects, the upgrade procedure, the validation reports and scoring methods, and the model configurations and assimilation systems validated. Of special concern are the forecasts of high pollution concentration events (fires, dust storms, air pollution events, volcano ash and SO2). A few interesting validation results will be shown.

  5. Verification of Space Weather Forecasts using Terrestrial Weather Approaches

    Science.gov (United States)

    Henley, E.; Murray, S.; Pope, E.; Stephenson, D.; Sharpe, M.; Bingham, S.; Jackson, D.

    2015-12-01

    The Met Office Space Weather Operations Centre (MOSWOC) provides a range of 24/7 operational space weather forecasts, alerts, and warnings, which provide valuable information on space weather that can degrade electricity grids, radio communications, and satellite electronics. Forecasts issued include arrival times of coronal mass ejections (CMEs), and probabilistic forecasts for flares, geomagnetic storm indices, and energetic particle fluxes and fluences. These forecasts are produced twice daily using a combination of output from models such as Enlil, near-real-time observations, and forecaster experience. Verification of forecasts is crucial for users, researchers, and forecasters to understand the strengths and limitations of forecasters, and to assess forecaster added value. To this end, the Met Office (in collaboration with Exeter University) has been adapting verification techniques from terrestrial weather, and has been working closely with the International Space Environment Service (ISES) to standardise verification procedures. We will present the results of part of this work, analysing forecast and observed CME arrival times, assessing skill using 2x2 contingency tables. These MOSWOC forecasts can be objectively compared to those produced by the NASA Community Coordinated Modelling Center - a useful benchmark. This approach cannot be taken for the other forecasts, as they are probabilistic and categorical (e.g., geomagnetic storm forecasts give probabilities of exceeding levels from minor to extreme). We will present appropriate verification techniques being developed to address these forecasts, such as rank probability skill score, and comparing forecasts against climatology and persistence benchmarks. As part of this, we will outline the use of discrete time Markov chains to assess and improve the performance of our geomagnetic storm forecasts. We will also discuss work to adapt a terrestrial verification visualisation system to space weather, to help

  6. Desert dust hazards: A global review

    Science.gov (United States)

    Middleton, N. J.

    2017-02-01

    Dust storms originate in many of the world's drylands and frequently present hazards to human society, both within the drylands themselves but also outside drylands due to long-range transport of aeolian sediments. Major sources of desert dust include the Sahara, the Middle East, central and eastern Asia, and parts of Australia, but dust-raising occurs all across the global drylands and, on occasion, beyond. Dust storms occur throughout the year and they vary in frequency and intensity over a number of timescales. Long-range transport of desert dust typically takes place along seasonal transport paths. Desert dust hazards are here reviewed according to the three phases of the wind erosion system: where dust is entrained, during the transport phase, and on deposition. This paper presents a synthesis of these hazards. It draws on empirical examples in physical geography, medical geology and geomorphology to discuss case studies from all over the world and in various fields. These include accelerated soil erosion in agricultural zones - where dust storms represent a severe form of accelerated soil erosion - the health effects of air pollution caused by desert aerosols via their physical, chemical and biological properties, transport accidents caused by poor visibility during desert dust events, and impacts on electricity generation and distribution. Given the importance of desert dust as a hazard to human societies, it is surprising to note that there have been relatively few attempts to assess their impact in economic terms. Existing studies in this regard are also reviewed, but the wide range of impacts discussed in this paper indicates that desert dust storms deserve more attention in this respect.

  7. CyberStorm III

    NARCIS (Netherlands)

    Luiijf, H.A.M.; et al

    2010-01-01

    Projectteam Cyber Storm III - De Verenigde Staten organiseerden de afgelopen jaren een reeks grootschalige ICT-crisisoefeningen met de naam Cyber Storm. Cyber Storm III is de derde oefening in de reeks. Het scenario van Cyber Storm III staat in het teken van grootschalige ICT-verstoringen, waarbij n

  8. 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

  9. Forecasting Skill

    Science.gov (United States)

    1981-01-01

    indicated that forecasting experience has little relationship to forecasting performance. In the latter three studies, neophyte forecasters became... Europe . Within a few months after a new commander was assigned, this unit’s performance rose to first place in the theater and remained there

  10. Adaptive mesh refinement for storm surge

    KAUST Repository

    Mandli, Kyle T.

    2014-03-01

    An approach to utilizing adaptive mesh refinement algorithms for storm surge modeling is proposed. Currently numerical models exist that can resolve the details of coastal regions but are often too costly to be run in an ensemble forecasting framework without significant computing resources. The application of adaptive mesh refinement algorithms substantially lowers the computational cost of a storm surge model run while retaining much of the desired coastal resolution. The approach presented is implemented in the GeoClaw framework and compared to ADCIRC for Hurricane Ike along with observed tide gauge data and the computational cost of each model run. © 2014 Elsevier Ltd.

  11. Adaptive Mesh Refinement for Storm Surge

    CERN Document Server

    Mandli, Kyle T

    2014-01-01

    An approach to utilizing adaptive mesh refinement algorithms for storm surge modeling is proposed. Currently numerical models exist that can resolve the details of coastal regions but are often too costly to be run in an ensemble forecasting framework without significant computing resources. The application of adaptive mesh refinement algorithms substantially lowers the computational cost of a storm surge model run while retaining much of the desired coastal resolution. The approach presented is implemented in the \\geoclaw framework and compared to \\adcirc for Hurricane Ike along with observed tide gauge data and the computational cost of each model run.

  12. Forecasting Thermosphere Density: an Overview

    Science.gov (United States)

    Bruinsma, S.

    2015-12-01

    Our knowledge of the thermosphere has improved considerably since 2000 thanks to the availability of high-resolution accelerometer inferred densities. Consequently, precision and shortcomings of thermosphere models are better known. Thermosphere density forecast accuracy is limited by: 1) the accuracy of the thermosphere model 2) the solar and geomagnetic activity forecast 3) the quality of the data assimilation system. The precision of semi-empirical thermosphere models is 10-25%. Solar activity forecasts can be accurate up to 5 days. They become less accurate with time, but some proxies are more forecastable than others. Geomagnetic activity forecasting is more problematic, since in most cases storm events cannot be predicted on any time scale. The forecast accuracy is ultimately bounded by the thermosphere model precision and the (varying) degree to which mainly the solar proxy represents EUV heating of the atmosphere. Both errors can be corrected for by means of near real time (nrt) assimilation of satellite drag data, provided that the data is of high quality. At present, only the classified High Accuracy Satellite Drag Model of the Air Force has that capability operationally, even if other prototype nrt models have been developed. Data assimilation significantly improves density forecasts up to 72-hours out; there is no gain for longer periods due to the short memory of the thermosphere system. Only physical models, e.g. TIMEGCM and CTIPe, can in principle reproduce the dynamic changes in density for example during geomagnetic storms. However, accurate information on atmospheric heating is often missing, or not used. When it is, observed and modeled Traveling Atmospheric Disturbances are very similar. Nonmigrating tides and waves propagating from the lower atmosphere cause longitudinal density variations; sources of geophysical noise for semi-empirical models, they can be predicted qualitatively and sometimes quantitatively with physical models. This

  13. The formation of a large summertime Saharan dust plume: Convective and synoptic-scale analysis

    Science.gov (United States)

    Roberts, A. J.; Knippertz, P.

    2014-02-01

    Haboobs are dust storms produced by the spreading of evaporatively cooled air from thunderstorms over dusty surfaces and are a major dust uplift process in the Sahara. In this study observations, reanalysis, and a high-resolution simulation using the Weather Research and Forecasting model are used to analyze the multiscale dynamics which produced a long-lived (over 2 days) Saharan mesoscale convective system (MCS) and an unusually large haboob in June 2010. An upper level trough and wave on the subtropical jet 5 days prior to MCS initiation produce a precipitating tropical cloud plume associated with a disruption of the Saharan heat low and moistening of the central Sahara. The restrengthening Saharan heat low and a Mediterranean cold surge produce a convergent region over the Hoggar and Aïr Mountains, where small convective systems help further increase boundary layer moisture. Emerging from this region the MCS has intermittent triggering of new cells, but later favorable deep layer shear produces a mesoscale convective complex. The unusually large size of the resulting dust plume (over 1000 km long) is linked to the longevity and vigor of the MCS, an enhanced pressure gradient due to lee cyclogenesis near the Atlas Mountains, and shallow precipitating clouds along the northern edge of the cold pool. Dust uplift processes identified are (1) strong winds near the cold pool front, (2) enhanced nocturnal low-level jet within the aged cold pool, and (3) a bore formed by the cold pool front on the nocturnal boundary layer.

  14. A high resolution water level forecast for the German Bight

    Science.gov (United States)

    Niehüser, Sebastian; Dangendorf, Sönke; Arns, Arne; Jensen, Jürgen

    2016-04-01

    Many coastal regions worldwide are potentially endangered by storm surges which can cause disastrous damages and loss of life. Due to climate change induced sea level rise, an accumulation of such events is expected by the end of the 21th century. Therefore, advanced storm surge warnings are needed to be prepared when another storm surge hits the coast. In the shallow southeastern North Sea these storm surge warnings are nowadays routinely provided for selected tide gauge locations along a coastline through state-of-the-art forecast systems, which are based on a coupled system of empirical tidal predictions and numerical storm surge forecasts. Along the German North Sea coastline, the Federal Maritime and Hydrographic Agency in cooperation with the German Weather Service is responsible for the storm surge warnings. They provide accurate, high frequency and real-time water level forecasts for up to six days ahead at selected tide gauge sites via internet, telephone and broadcast. Since water levels along the German North Sea coastline are dominated by shallow water effects and a very complex bathymetric structure of the seabed, the pointwise forecast is not necessarily transferable to un-gauged areas between the tide gauges. Here we aim to close this existing gap and develop water level forecasts with a high spatial (continuously with a resolution of at least 1 kilometer) as well as a high temporal (at least 15-minute values) resolution along the entire German North Sea coastline. We introduce a new methodology for water level forecasts which combines empirical or statistical and numerical models. While the tidal forecast is performed by non-parametric interpolation techniques between un-gauged and gauged sites, storm surges are estimated on the basis of statistical/empirical storm surge formulas taken from a numerical model hindcast. The procedure will be implemented in the operational mode forced with numerical weather forecasts.

  15. Southern Dust Devils

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Released 9 July 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth. Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms. In our final dust devil image we are again looking at the southern hemisphere of Mars. These tracks occur mainly on the northeast side of the topographic ridges. Of course, there are many exceptions, which makes understanding the dynamics that initiate the actual dust devil cyclone difficult. Image information: VIS instrument. Latitude -47.6, Longitude 317.3 East (42.7 West). 19 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed

  16. Plentiful Dust Devils

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Released 8 July 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth. Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms. These dust devil tracks occur on the northern plains of Mars. The majority of the surface seen in the image has been affected by the passage of dust devils. Image information: VIS instrument. Latitude -54.6, Longitude 79.3 East (280.7 West). 19 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are

  17. Seasonal variations of dust record in the Muztagata ice cores

    Institute of Scientific and Technical Information of China (English)

    WU GuangJian; YAO TanDong; XU BaiQing; TIAN LiDe; LI Zhen; DUAN KeQin

    2008-01-01

    Based on the oxygen isotope ratio and microparticle record in ice cores recovered at Mt.Muztagata,Eastern Pamirs,the seasonal variations of atmospheric dust have been reconstructed for the past four decades.High dust concentrations and coarser particle grains have the similar trend with oxygen iso-tope value.Our statistical results indicate that 50%--60% high dust concentration samples occur dur-ing the season with high oxygen isotope values (summer),while low dust storm frequency during spring and winter.Back-trajectory analysis shows that the air mass hitting Muztagata predominately came from West Asia (such as Iran-Afghanistan Plateau) and Central Asia,which are the main dust source area for Muztagata.Dust storms in those source areas most frequently occur during summer (from May to August),while frequent dust storm events in northern China mainly occur during spring (March to May).Regions in the path of Asian dust transport,such as in Japan,the North Pacific,and Greenland,also show high dust concentrations during spring (from March to May).Our results indicate that dust storms have different seasonality in different regions within Asia.

  18. New dust opacity mapping from Viking Infrared Thermal Mapper data

    Science.gov (United States)

    Martin, Terry Z.; Richardson, Mark I.

    1993-01-01

    Global dust opacity mapping for Mars has been carried forward using the approach described by Martin (1986) for Viking IR Thermal Mapper data. New maps are presented for the period from the beginning of Viking observations, until Ls 210 deg in 1979 (1.36 Mars years). This range includes the second and more extensive planet-encircling dust storm observed by Viking, known as storm 1977b. Improvements in approach result in greater time resolution and smaller noise than in the earlier work. A strong local storm event filled the Hellas basin at Ls 170 deg, prior to the 1977a storm. Dust is retained in equatorial regions following the 1977b storm far longer than in mid-latitudes. Minor dust events appear to raise the opacity in northern high latitudes during northern spring. Additional mapping with high time resolution has been done for the periods of time near the major storm origins in order to search for clues to the mechanism of storm initiation. The first evidence of the start of the 1977b storm is pushed back to Ls 274.2 deg, preceding signs of the storm in images by about 15 hours.

  19. Coupling Mars' Dust and Water Cycles: Effects on Dust Lifting Vigor, Spatial Extent and Seasonality

    Science.gov (United States)

    Kahre, M. A.; Hollingsworth, J. L.; Haberle, R. M.; Montmessin, F.

    2012-01-01

    The dust cycle is an important component of Mars' current climate system. Airborne dust affects the radiative balance of the atmosphere, thus greatly influencing the thermal and dynamical state of the atmosphere. Dust raising events on Mars occur at spatial scales ranging from meters to planet-wide. Although the occurrence and season of large regional and global dust storms are highly variable from one year to the next, there are many features of the dust cycle that occur year after year. Generally, a low-level dust haze is maintained during northern spring and summer, while elevated levels of atmospheric dust occur during northern autumn and winter. During years without global-scale dust storms, two peaks in total dust loading were observed by MGS/TES: one peak occurred before northern winter solstice at Ls 200-240, and one peak occurred after northern winter solstice at L(sub s) 305-340. These maxima in dust loading are thought to be associated with transient eddy activity in the northern hemisphere, which has been observed to maximize pre- and post-solstice. Interactive dust cycle studies with Mars General Circulation Models (MGCMs) have included the lifting, transport, and sedimentation of radiatively active dust. Although the predicted global dust loadings from these simulations capture some aspects of the observed dust cycle, there are marked differences between the simulated and observed dust cycles. Most notably, the maximum dust loading is robustly predicted by models to occur near northern winter solstice and is due to dust lifting associated with down slope flows on the flanks of the Hellas basin. Thus far, models have had difficulty simulating the observed pre- and post- solstice peaks in dust loading. Interactive dust cycle studies typically have not included the formation of water ice clouds or their radiative effects. Water ice clouds can influence the dust cycle by scavenging dust from atmosphere and by interacting with solar and infrared radiation

  20. Long-Term Variations, Signatures, Sources of Asian Dust and Role of Climate Change Versus Desertification in Asian Dust Emission

    Institute of Scientific and Technical Information of China (English)

    X.Y. Zhang; S.L. Gong; T.L. Zhao; R. Arimoto; Y.Q. Wang; Z.J. Zhou

    2004-01-01

    @@ For long-term variations and elemental signatures of Asian dust aerosol, changes in mass, twenty elemental concentrations over the period 2001~2003 were assessed from five surface-based stations in western, northern, northeast deserts, the Loess Plateau and the coastal areas in China. Together with the back trajectory analyses and visibility observations, the elemental signatures of soil dust aerosol from different air-mass clusters were characterized for the dust storm (DS) and non-dust storm (N-DS)conditions, respectively.

  1. Demand forecasting

    OpenAIRE

    Gregor, Belčec

    2011-01-01

    Companies operate in an increasingly challenging environment that requires them to continuously improve all areas of the business process. Demand forecasting is one area in manufacturing companies where we can hope to gain great advantages. Improvements in forecasting can result in cost savings throughout the supply chain, improve the reliability of information and the quality of the service for our customers. In the company Danfoss Trata, d. o. o. we did not have a system for demand forecast...

  2. Forecasting the 12-14 March 1993 superstorm

    Energy Technology Data Exchange (ETDEWEB)

    Uccellini, L.W.; Kocin, P.J.; Schneider, R.S.; Stokols, P.M.; Dorr, R.A. [National Weather Service, Camp Springs, MD (United States)]|[National Weather Service, Bohemia, NY (United States)

    1995-02-01

    This paper describes the decision-making process used by the forecasters in the National Meteorological Center`s (NMC`s) Meterolological Operations Division and in Weather Forecast Offices of the National Weather Service to provide the successful forecasts of the superstorm of 12-14 March 1993. This review illustrates (1) the difficult decisions forecasters faced when using sometimes conflicting model guidance, (2) the forecasters` success in recognizing the mesoscale aspects of the storm as it began to develop and move along the Gulf and East Coasts of the United States, and (3) their ability to produce one of the most successful heavy snow and blizzard forecasts ever for a major winter storm that affected the eastern third of the United States. The successful aspects of the forecasts include the following. (1) Cyclogenesis was predicted up to 5 days prior to its onset. (2) The unusual intensity of the storm was predicted three days in advance, allowing forecasters, government officials, and the media ample time to prepare the public, marine, and aviation interests to take precautions for the protection of life and property. (3) The excessive amounts and areal distribution of snowfall were prediceted two days in advance of its onset. (4) An extensive number of blizzard watches and warnings were issued throughout the eastern United States with unprecedented lead times. (5) The coordination of forecasts within the National Weather Service and between the National Weather Service, private forecasters, and media meteorologists was perhaps the most extensive in recent history.

  3. 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...

  4. On The Usage Of Fire Smoke Emissions In An Air Quality Forecasting System To Reduce Particular Matter Forecasting Error

    Science.gov (United States)

    Huang, H. C.; Pan, L.; McQueen, J.; Lee, P.; ONeill, S. M.; Ruminski, M.; Shafran, P.; DiMego, G.; Huang, J.; Stajner, I.; Upadhayay, S.; Larkin, N. K.

    2016-12-01

    Wildfires contribute to air quality problems not only towards primary emissions of particular matters (PM) but also emitted ozone precursor gases that can lead to elevated ozone concentration. Wildfires are unpredictable and can be ignited by natural causes such as lightning or accidently by human negligent behavior such as live cigarette. Although wildfire impacts on the air quality can be studied by collecting fire information after events, it is extremely difficult to predict future occurrence and behavior of wildfires for real-time air quality forecasts. Because of the time constraints of operational air quality forecasting, assumption of future day's fire behavior often have to be made based on observed fire information in the past. The United States (U.S.) NOAA/NWS built the National Air Quality Forecast Capability (NAQFC) based on the U.S. EPA CMAQ to provide air quality forecast guidance (prediction) publicly. State and local forecasters use the forecast guidance to issue air quality alerts in their area. The NAQFC fine particulates (PM2.5) prediction includes emissions from anthropogenic and biogenic sources, as well as natural sources such as dust storms and fires. The fire emission input to the NAQFC is derived from the NOAA NESDIS HMS fire and smoke detection product and the emission module of the US Forest Service BlueSky Smoke Modeling Framework. This study focuses on the error estimation of NAQFC PM2.5 predictions resulting from fire emissions. The comparisons between the NAQFC modeled PM2.5 and the EPA AirNow surface observation show that present operational NAQFC fire emissions assumption can lead to a huge error in PM2.5 prediction as fire emissions are sometimes placed at wrong location and time. This PM2.5 prediction error can be propagated from the fire source in the Northwest U.S. to downstream areas as far as the Southeast U.S. From this study, a new procedure has been identified to minimize the aforementioned error. An additional 24 hours

  5. Assessment of dust activity and dust-plume pathways over Jazmurian Basin, southeast Iran

    Science.gov (United States)

    Rashki, A.; Arjmand, M.; Kaskaoutis, D. G.

    2017-02-01

    Jazmurian (or hamun-e Jaz Murian) is a dried lake located in a topographic-low basin in southeast Iran and a major source for high dust emissions under favorable weather conditions. This work examines for the first time the dust activity over the basin by classifying the dust events (DEs, visibility Iran, while no significant tendency is found during the period 1990-2013. Further, the DEs and DSEs exhibit a clear diurnal pattern with highest frequency between 15:30 and 18:30 LST due to thermal convection and transported dust plumes. The analysis reveals an average frequency of 12.7 dust-storm days per year, while the DSEs last for 5.1 h, on average, during the dust-storm days. The dust storms originating from Jazmurian affect mostly the northern coast of the Arabian Sea (Makran mountains), the Oman Sea, the southeastern Arabian Peninsula and the western Pakistan, while air masses from the arid/desert areas of central-eastern Iran and Arabia seem to further aggravate the dust-aerosol loading over Jazmurian.

  6. WMO SDS-WAS NAMEE Regional Center: Towards continuous evaluation of dust models in Northern Africa

    Science.gov (United States)

    Basart, Sara; García-Castillo, Gerardo; Cuevas, Emilio; Terradellas, Enric

    2016-04-01

    One of the most important activities of the Regional Center for Northern Africa, Middle East and Europe of the World Meteorological Organization's Sand and Dust Storm Warning Advisory and Assessment System (WMO SDS-WAS, http://sds-was.aemet.es) is the dust model intercomparison and forecast evaluation, which is deemed an indispensable service to the users and an invaluable tool to assess model skills. Currently, the Regional Center collects daily dust forecasts from models run by nine partners (BSC, ECMWF, NASA, NCEP, SEEVCCC, EMA, CNR-ISAC, NOA and UK Met Office). A multi-model ensemble has also been set up in an effort to provide added-value products to the users. The first problem to address the dust model evaluation is the scarcity of suitable routine observations near the Sahara, the world's largest source of mineral dust. The present contribution presents preliminary results of dust model evaluation using new observational datasets. The current routine evaluation of dust predictions is focused on total-column dust optical depth (DOD) and uses remote-sensing retrievals from sun-photometric (AERONET) and satellite (MODIS) measurements. However, most users of dust forecasts are interested in the concentration near the surface (in the air we breathe) rather than in the total column content. Therefore, evaluation of the predicted surface concentration is also necessary. In this context, the initiative of the African Monsoon Interdisciplinary Analysis (AMMA) International Program to establish permanent measuring stations in the Sahel is extremely important. Tapered Element Oscillating Microbalance (TEOM) monitors continuously record PM10 in M'Bour (Senegal); Cinzana (Mali) and Banizoumbou (Niger). This surface model evaluation is complemented with the PM10 observation from the Air Quality Control and Monitoring Network (AQCMN) of the Canary Islands (Spain). The region, located in the sub-tropical Eastern Atlantic (roughly 100 km west of the Moroccan coast), is

  7. A complex adaptive system approach to forecasting hurricane tracks

    OpenAIRE

    Lear, Matthew R.

    2005-01-01

    , for the life of the storm, perform the best in terms of the distance between forecast and best-track positions. A TAF forecast is developed using a linear combination of the highest weighted predictors. When applied to the 2004 Atlantic hurricane season, the TAF system with a requirement to contain a minimum of three predictors, consistently outperformed, although not statistically significant, the CONU forecast at 72 and 96 hours for a homogeneous data set. At 120 hours, the TAF system s...

  8. Numerical modeling of windblown dust in the Pacific Northwest with improved meteorology and dust emission models

    Science.gov (United States)

    Sundram, Irra; Claiborn, Candis; Strand, Tara; Lamb, Brian; Chandler, Dave; Saxton, Keith

    2004-12-01

    Soil erosion by wind is a serious consequence of dry land agriculture in eastern Washington, where the main adverse effects are loss of nutrient-rich soil, reduced visibility during dust storms and degradation of air quality. A multidisciplinary research effort to study windblown dust in central and eastern Washington was initiated under the Columbia Plateau PM10 (CP3) program, which involved measuring wind erosion and windblown dust emissions at sites throughout the region and developing a transport and dispersion model for the area. The modeling system includes the prognostic meteorological model, Mesoscale Metorological Model Version 5 (MM5), coupled with the CALMET/CALGRID Eularian modeling pair and a new dust emission module (EMIT-PM). Improvements to the modeling system included employing higher spatial resolutions for the meteorological models and improved parameterizations of emission factors in EMIT-PM. Meteorological fields, dust emissions and the resulting dust concentrations were simulated for six historical regional dust storms: 23 November 1990, 21 October 1991, 11 September 1993, 3 November 1993, 30 August 1996 and 23-25 September 1999. For all the simulated events, with the exception of the August 1996 event, ratios of observed to predicted concentrations were favorable, within a range of 0.5-6.0 without calibration of the dust emission model; PM10 emissions averaged 22 Gg per 24-hour event, representing approximately 1% of the daily dust flux on a global basis. These results showed that the model performed best for large, strong dust storms but did not simulate smaller storms as well.

  9. European Winter Storms in the ECMWF Ensemble Prediction System

    Science.gov (United States)

    Osinski, Robert; Lorenz, Philip; Kruschke, Tim; Leckebusch, Gregor C.; Ulbrich, Uwe

    2013-04-01

    As European winter storms can provoke very large damages, estimations of the probability of occurrence are of economical and sociological importance. The estimations of return periods for the strongest events underlie large uncertainties, which arise from the limited available data, available from historical meteorological records or reanalysis data. A gain of information can be obtained from ensemble forecasts. In this work the Ensemble Prediction System (EPS) from the European Center of Medium-Range Weather Forecast (ECMWF) is analyzed for its suitability to improve the estimates of return periods of very rare and severe events. The EPS dataset contains up to 51 ensemble members, starting twice a day and each integrated over 10 days. The storm systems are identified and characterized using a wind field tracking algorithm developed by Leckebusch et al. (2008). Exceedances of the local 98th percentile of 10m wind speed are used, and calculating the cube of these exceedances, accumulated spatially and temporally, an objective storm severity measure (SSI) is determined. Taking the distribution of values into account, the measure of storm severity relates to storm damages. Using ERA-Interim as a reference dataset, it is shown that the general distributions of storm properties in the EPS are realistic. The EPS representations of a single ERA-Interim storm show a wide range of variability in terms of size, duration and severity. Hence better estimations of return periods of winter storms are possible using the EPS, as well as studies of general aspects of storms, like the correlation between intensification and storm duration. Nevertheless for an estimation of return periods, it must be taken into account, that the simulated events in the EPS are not independent of each other.

  10. Innovation Forecasting

    Science.gov (United States)

    1997-11-01

    relating to “ injectors ”) to develop a map of the related technologies [33.] Another approach is to develop a “tree” showing a system branching into its...additional terms such as “trend,” “forecast,” “ delphi ,” “assessment,” and so forth may call up other forecasts and assessments relating to the topic...present and future engine technologies. A preliminary search (Step 1, Table 5) located prior forecasts, in particular, a Delphi study [36]. The Delphi

  11. Subtropical Storm Andrea

    Science.gov (United States)

    2007-01-01

    The circling clouds of an intense low-pressure system sat off the southeast coast of the United States on May 8, 2007, when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite captured this image. By the following morning, the storm developed enough to be classified as a subtropical storm, a storm that forms outside of the tropics, but has many of the characteristics--hurricane-force winds, driving rains, low pressure, and sometimes an eye--of a tropical storm. Although it arrived several weeks shy of the official start of the hurricane season (June 1), Subtropical Storm Andrea became the first named storm of the 2007 Atlantic hurricane season. The storm has the circular shape of a tropical cyclone in this image, but lacks the tight organization seen in more powerful storms. By May 9, the storm's winds reached 75 kilometers per hour (45 miles per hour), and the storm was not predicted to get any stronger, said the National Hurricane Center. Though Subtropical Storm Andrea was expected to remain offshore, its strong winds and high waves pummeled coastal states, prompting a tropical storm watch. The winds fueled wild fires (marked with red boxes) in Georgia and Florida. The wind-driven flames generated thick plumes of smoke that concentrated in a gray-brown mass over Tampa Bay, Florida. Unfortunately for Georgia and Florida, which are experiencing moderate to severe drought, Subtropical Storm Andrea was not predicted to bring significant rain to the region right away, according to reports on the Washington Post Website.

  12. Strategic Forecasting

    DEFF Research Database (Denmark)

    Duus, Henrik Johannsen

    2016-01-01

    Purpose: The purpose of this article is to present an overview of the area of strategic forecasting and its research directions and to put forward some ideas for improving management decisions. Design/methodology/approach: This article is conceptual but also informed by the author’s long contact...... and collaboration with various business firms. It starts by presenting an overview of the area and argues that the area is as much a way of thinking as a toolbox of theories and methodologies. It then spells out a number of research directions and ideas for management. Findings: Strategic forecasting is seen...... as a rebirth of long range planning, albeit with new methods and theories. Firms should make the building of strategic forecasting capability a priority. Research limitations/implications: The article subdivides strategic forecasting into three research avenues and suggests avenues for further research efforts...

  13. Exposure Forecaster

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Exposure Forecaster Database (ExpoCastDB) is EPA's database for aggregating chemical exposure information and can be used to help with chemical exposure...

  14. How well do analyses capture dust-generating winds in the Sahara and Sahel?

    Science.gov (United States)

    Roberts, Alexander; Marsham, John; Knippertz, Peter; Parker, Douglas

    2016-04-01

    Airborne mineral dust is important for weather, climate and earth-system prediction. Uncertainty in winds, as well as the land-surface, are known to be key to model uncertainties for dust uplift. Recent research has shown that during the summer wet season in the Sahel strong winds generated by the cold outflow from organized convective systems are an important dust storm mechanism (so called haboobs), while over the inner Sahara nocturnal low-level jets forming on the pressure gradient around the heat low dominate. Together the Sahel and Sahara are the world's largest dust source. Until now there has been a severe shortage of data for evaluating models for this region. Here, we bring together new observations from the remote Sahara, made during the Fennec project, with Sahelian data from the African Monsoon Multidisciplinary Analysis (AMMA), to provide an unprecedented evaluation of dust-generating winds in the European Centre for Medium-Range Weather Forecasts ERA-Interim (ERA-I) reanalysis. Differences between observations and ERA-I are explored with specific attention to monsoon and non-monsoon influenced regions. The main results are: (1) High speed winds in instantaneous ERA-I grid-box mean winds are lacking compared to time-averaged wind speed observations; (2) agreement between ERA-I and observations is lower during the monsoon season, even in parts of the Sahara not directly affected by the monsoon; and (3) both the seasonal and diurnal variability is under-represented in ERA-I. ERA-I fails to capture the summertime maximum for monsoon-affected stations and seasonally, correlations between daily-mean ERA-I and observed winds vary from 0.8 to 0.4, with lower correlations for 3-hourly data. These differences demonstrate that the model used in the production of the ERA-I reanalysis is unable to represent some important dust uplift processes, especially during the monsoon season when moist convection plays a key role, and that the product is not sufficiently

  15. Characterizing Extreme Ionospheric Storms

    Science.gov (United States)

    Sparks, L.; Komjathy, A.; Altshuler, E.

    2011-12-01

    Ionospheric storms consist of disturbances of the upper atmosphere that generate regions of enhanced electron density typically lasting several hours. Depending upon the storm magnitude, gradients in electron density can sometimes become large and highly localized. The existence of such localized, dense irregularities is a major source of positioning error for users of the Global Positioning System (GPS). Consequently, satellite-based augmentation systems have been implemented to improve the accuracy and to ensure the integrity of user position estimates derived from GPS measurements. Large-scale irregularities generally do not pose a serious threat to estimate integrity as they can be readily detected by such systems. Of greater concern, however, are highly localized irregularities that interfere with the propagation of a signal detected by a user measurement but are poorly sampled by the receivers in the system network. The most challenging conditions have been found to arise following disturbances of large magnitude that occur only rarely over the course of a solar cycle. These extremely disturbed conditions exhibit behavior distinct from moderately disturbed conditions and, hence, have been designated "extreme storms". In this paper we examine and compare the behavior of the extreme ionospheric storms of solar cycle 23 (or, more precisely, extreme storms occurring between January 1, 2000, and December 31, 2008), as represented in maps of vertical total electron content. To identify these storms, we present a robust means of quantifying the regional magnitude of an ionospheric storm. Ionospheric storms are observed frequently to occur in conjunction with magnetic storms, i.e., periods of geophysical activity as measured by magnetometers. While various geomagnetic indices, such as the disturbance storm time (Dst) and the planetary Kp index, have long been used to rank the magnitudes of distinct magnetic storms, no comparable, generally recognized index exists for

  16. Technical Note: High-resolution mineralogical database of dust-productive soils for atmospheric dust modeling

    Directory of Open Access Journals (Sweden)

    S. Nickovic

    2012-01-01

    Full Text Available Dust storms and associated mineral aerosol transport are driven primarily by meso- and synoptic-scale atmospheric processes. It is therefore essential that the dust aerosol process and background atmospheric conditions that drive dust emissions and atmospheric transport are represented with sufficiently well-resolved spatial and temporal features. The effects of airborne dust interactions with the environment determine the mineral composition of dust particles. The fractions of various minerals in aerosol are determined by the mineral composition of arid soils; therefore, a high-resolution specification of the mineral and physical properties of dust sources is needed.

    Several current dust atmospheric models simulate and predict the evolution of dust concentrations; however, in most cases, these models do not consider the fractions of minerals in the dust. The accumulated knowledge about the impacts of the mineral composition in dust on weather and climate processes emphasizes the importance of including minerals in modeling systems. Accordingly, in this study, we developed a global dataset consisting of the mineral composition of the current potentially dust-producing soils. In our study, we (a mapped mineral data to a high-resolution 30 s grid, (b included several mineral-carrying soil types in dust-productive regions that were not considered in previous studies, and (c included phosphorus.

  17. Characterization of aerosolized bacteria and fungi from desert dust events in Mali, West Africa

    Science.gov (United States)

    Kellogg, C.A.; Griffin, Dale W.; Garrison, V.H.; Peak, K.K.; Royall, N.; Smith, R.R.; Shinn, E.A.

    2004-01-01

    Millions of metric tons of African desert dust blow across the Atlantic Ocean each year, blanketing the Caribbean and southeastern United States. Previous work in the Caribbean has shown that atmospheric samples collected during dust events contain living microbes, including plant and opportunistic human pathogens. To better understand the potential downwind public health and ecosystem effects of the dust microbes, it is important to characterize the source population. We describe 19 genera of bacteria and 3 genera of fungi isolated from air samples collected in Mali, a known source region for dust storms, and over which large dust storms travel.

  18. Assessment of Modeling Capability for Reproducing Storm Impacts on TEC

    Science.gov (United States)

    Shim, J. S.; Kuznetsova, M. M.; Rastaetter, L.; Bilitza, D.; Codrescu, M.; Coster, A. J.; Emery, B. A.; Foerster, M.; Foster, B.; Fuller-Rowell, T. J.; Huba, J. D.; Goncharenko, L. P.; Mannucci, A. J.; Namgaladze, A. A.; Pi, X.; Prokhorov, B. E.; Ridley, A. J.; Scherliess, L.; Schunk, R. W.; Sojka, J. J.; Zhu, L.

    2014-12-01

    During geomagnetic storm, the energy transfer from solar wind to magnetosphere-ionosphere system adversely affects the communication and navigation systems. Quantifying storm impacts on TEC (Total Electron Content) and assessment of modeling capability of reproducing storm impacts on TEC are of importance to specifying and forecasting space weather. In order to quantify storm impacts on TEC, we considered several parameters: TEC changes compared to quiet time (the day before storm), TEC difference between 24-hour intervals, and maximum increase/decrease during the storm. We investigated the spatial and temporal variations of the parameters during the 2006 AGU storm event (14-15 Dec. 2006) using ground-based GPS TEC measurements in the selected 5 degree eight longitude sectors. The latitudinal variations were also studied in two longitude sectors among the eight sectors where data coverage is relatively better. We obtained modeled TEC from various ionosphere/thermosphere (IT) models. The parameters from the models were compared with each other and with the observed values. We quantified performance of the models in reproducing the TEC variations during the storm using skill scores. This study has been supported by the Community Coordinated Modeling Center (CCMC) at the Goddard Space Flight Center. Model outputs and observational data used for the study will be permanently posted at the CCMC website (http://ccmc.gsfc.nasa.gov) for the space science communities to use.

  19. Seasonal Contribution of Mineral Dust and Otlher Major Components to Particulate Matter at Two Remote Sites in Central Asia

    Science.gov (United States)

    Dust storms are significant contributors to ambient levels of particulate matter (PM) in many areas of the world. Central Asia, an area that is relatively understudied in this regard, is anticipated to be affected by dust storms due to its proximity to several major deserts that ...

  20. Power grid disturbances and polar cap index during geomagnetic storms

    Science.gov (United States)

    Stauning, Peter

    2013-06-01

    The strong geomagnetic storm in the evening of 30 October 2003 caused high-voltage power grid disturbances in Sweden that expanded to produce hour-long power line outage in Malmö located in the southern part of the country. This was not a unique situation. The geomagnetic storm on 13 March 1989 caused extensive disruptions of high-voltage power circuits especially in the Province of Quebec, Canada, but also to a lesser degree in Scandinavia. Similar events have occurred earlier, among others, during the great storms of 13-14 July 1982 and 8-9 February 1986. These high-voltage power grid disturbances were related to impulsive magnetic variations accompanying extraordinarily intense substorm events. The events were preceded by lengthy intervals of unusually high values of the Polar Cap (PC) index caused by enhanced transpolar ionospheric convection. The transpolar convection transports magnetic flux from the dayside to nightside which causes equatorward displacements of the region of auroral activity enabling the substorms to hit vital power grids. During the 30 October 2003 event the intense solar proton radiation disabled the ACE satellite observations widely used to provide forecast of magnetic storm events. Hence in this case the alarmingly high PC index could provide useful warning of the storm as a back-up of the missing ACE-based forecast. In further cases, monitoring the PC index level could provide supplementary storm warnings to the benefit of power grid operators.

  1. Forecasting metal prices: Do forecasters herd?

    DEFF Research Database (Denmark)

    Pierdzioch, C.; Rulke, J. C.; Stadtmann, G.

    2013-01-01

    We analyze more than 20,000 forecasts of nine metal prices at four different forecast horizons. We document that forecasts are heterogeneous and report that anti-herding appears to be a source of this heterogeneity. Forecaster anti-herding reflects strategic interactions among forecasters...

  2. Allergies, asthma, and dust

    Science.gov (United States)

    Reactive airway disease - dust; Bronchial asthma - dust; Triggers - dust ... Things that make allergies or asthma worse are called triggers. Dust is a common trigger. When your asthma or allergies become worse due to dust, you are ...

  3. ECMWF Extreme Forecast Index for water vapor transport: A forecast tool for atmospheric rivers and extreme precipitation

    Science.gov (United States)

    Lavers, David A.; Pappenberger, Florian; Richardson, David S.; Zsoter, Ervin

    2016-11-01

    In winter, heavy precipitation and floods along the west coasts of midlatitude continents are largely caused by intense water vapor transport (integrated vapor transport (IVT)) within the atmospheric river of extratropical cyclones. This study builds on previous findings that showed that forecasts of IVT have higher predictability than precipitation, by applying and evaluating the European Centre for Medium-Range Weather Forecasts Extreme Forecast Index (EFI) for IVT in ensemble forecasts during three winters across Europe. We show that the IVT EFI is more able (than the precipitation EFI) to capture extreme precipitation in forecast week 2 during forecasts initialized in a positive North Atlantic Oscillation (NAO) phase; conversely, the precipitation EFI is better during the negative NAO phase and at shorter leads. An IVT EFI example for storm Desmond in December 2015 highlights its potential to identify upcoming hydrometeorological extremes, which may prove useful to the user and forecasting communities.

  4. Long range transport of fine grained sediments on Mars: Atmospheric dust loading, as inferred from Viking Lander imaging data

    Science.gov (United States)

    Pollack, J. B.; Colburn, D. S.

    1984-01-01

    During the first Viking year, two global dust storms occurred and they contributed about 90% of the dust suspended in the Martian atmosphere on a global average, over the course of this year. The remainder was due to the cumulative effect of local dust storms. When globally distributed, the amount of suspended dust introduced into the atmosphere this Martian year was about 5x10(-3) g/sq cm. This mass loading was derived from the incremental optical depths measured over this year and estimates of the mean size of the dust particles (2.5 microns). During the second Martian year, global dust storms were far more muted than during the first year. No near perihelion dust storm occurred, and a somewhat weaker dust storm may have occurred near the start of the spring season in the Southern Hemisphere, at about the same time that the first global dust storm of the first year occurred. Thus, the dust loading derived for the first Martian year may be somewhat higher than the average over many Martian years, a conclusion that appears to be supported by preliminary studies of Martian years beyond the second Viking year on Mars.

  5. Statistical Study of False Alarms of Geomagnetic Storms

    DEFF Research Database (Denmark)

    Leer, Kristoffer; Vennerstrøm, Susanne; Veronig, A.

    Coronal Mass Ejections (CMEs) are known to cause geomagnetic storms on Earth. However, not all CMEs will trigger geomagnetic storms, even if they are heading towards the Earth. In this study, front side halo CMEs with speed larger than 500 km/s have been identified from the SOHO LASCO catalogue....... A subset of these halo CMEs did not cause a geomagnetic storm the following four days and have therefore been considered as false alarms. The properties of these events are investigated and discussed here. Their statistics are compared to the geo-effective CMEs. The ability to identify potential false...... alarms is considered as an important factor when forecasting geomagnetic storms. It would therefore be very helpful if there were a signature in the solar data that could indicate that a CME is a false alarm. The strength and position of associated flares have been considered as possible candidates...

  6. Statistical Study of False Alarms of Geomagnetic Storms

    DEFF Research Database (Denmark)

    Leer, Kristoffer; Vennerstrøm, Susanne; Veronig, A.;

    Coronal Mass Ejections (CMEs) are known to cause geomagnetic storms on Earth. However, not all CMEs will trigger geomagnetic storms, even if they are heading towards the Earth. In this study, front side halo CMEs with speed larger than 500 km/s have been identified from the SOHO LASCO catalogue....... A subset of these halo CMEs did not cause a geomagnetic storm the following four days and have therefore been considered as false alarms. The properties of these events are investigated and discussed here. Their statistics are compared to the geo-effective CMEs. The ability to identify potential false...... alarms is considered as an important factor when forecasting geomagnetic storms. It would therefore be very helpful if there were a signature in the solar data that could indicate that a CME is a false alarm. The strength and position of associated flares have been considered as possible candidates...

  7. Using NORAPS for forecasting heavy precipitation with topographic forcing

    Energy Technology Data Exchange (ETDEWEB)

    Kong, J.; Leach, M.J.

    1997-02-01

    Heavy precipitation events, associated with winter storm systems, frequently produce devastating flooding throughout the state of California. One of the most disastrous floods in recent years occurred in March of 1995. A storm moved through California from March 7 to 11, 1995 causing flooding in a total of 57 counties in California. the storm moved to the northwest coast of California on March 7 and started producing heavy rainfall on March 8 in northern California. Then the storm moved southward and continuously produced heavy rain as it moved through California. On March 9, a maximum of 177 mm precipitation fell in northern California and brought a maximum of 140 mm precipitation to that area on March 10. In addition to the heavy rain, heavy snow fell in the higher elevations, with snow depths exceeding 12 meters in some locations in the Sierra Nevada mountains, reported by late March. Although such storms have been a research subject for many years, some features of the California storms, such as slow movement, the mesoscale structure and orographic effects on the storm movement and structure are not well understood. Consequently, storms such as the March 1995 event, are often not well predicted. The purpose of this study is to try to improve our understanding of the underlying physical mechanisms that produce the mesoscale structure and storm movement throughout the state. A greater understanding of the physical interactions un these storms will ultimately lead to improved precipitation forecasts, including both the spatial and temporal distribution. Improved forecasts benefit society by reducing threat to life and property and to improved water resource management. We have chosen the Navy Operational Regional Atmospheric Prediction System (NORAPS) to simulate the storms and study the dynamics and physics of these storm systems.

  8. Climatic controls on the interannual to decadal variability in Saudi Arabian dust activity: Toward the development of a seasonal dust prediction model

    Science.gov (United States)

    Yu, Yan; Notaro, Michael; Liu, Zhengyu; Wang, Fuyao; Alkolibi, Fahad; Fadda, Eyad; Bakhrjy, Fawzieh

    2015-03-01

    The observed climatic controls on springtime and summertime Saudi Arabian dust activities during 1975-2012 are analyzed, leading to development of a seasonal dust prediction model. According to empirical orthogonal function analysis, dust storm frequency exhibits a dominantly homogeneous pattern across Saudi Arabia, with distinct interannual and decadal variability. The previously identified positive trend in remotely sensed aerosol optical depth since 2000 is shown to be a segment of the decadal oscillation in dust activity, according to long-duration station record. Regression and correlation analyses reveal that the interannual variability in Saudi Arabian dust storm frequency is regulated by springtime rainfall across the Arabian Peninsula and summertime Shamal wind intensity. The key drivers of Saudi Arabian dust storm variability are identified. Winter-to-spring La Niña enhances subsequent spring dust activity by decreasing rainfall across the country's primary dust source region, the Rub' al Khali Desert. A relatively cool tropical Indian Ocean favors frequent summer dust storms by producing an anomalously anticyclonic circulation over the central Arabian Peninsula, which enhances the Shamal wind. Decadal variability in Saudi Arabian dust storm frequency is associated with North African rainfall and Sahel vegetation, which regulate African dust emissions and transport to Saudi Arabia. Mediterranean sea surface temperatures (SSTs) also regulate decadal dust variability, likely through their influence on Sahel rainfall and Shamal intensity. Using antecedent-accumulated rainfall over the Arabian Peninsula and North Africa, and Mediterranean SSTs, as low-frequency predictors, and tropical eastern Pacific and tropical Indian Ocean SSTs as high-frequency predictors, Saudi Arabia's seasonal dust activity is well predicted.

  9. General forecasting correcting formula

    OpenAIRE

    Harin, Alexander

    2009-01-01

    A general forecasting correcting formula, as a framework for long-use and standardized forecasts, is created. The formula provides new forecasting resources and new possibilities for expansion of forecasting including economic forecasting into the areas of municipal needs, middle-size and small-size business and, even, to individual forecasting.

  10. General forecasting correcting formula

    OpenAIRE

    2009-01-01

    A general forecasting correcting formula, as a framework for long-use and standardized forecasts, is created. The formula provides new forecasting resources and new possibilities for expansion of forecasting including economic forecasting into the areas of municipal needs, middle-size and small-size business and, even, to individual forecasting.

  11. Information Forecasting.

    Science.gov (United States)

    Hanneman, Gerhard J.

    Information forecasting provides a means of anticipating future message needs of a society or predicting the necessary types of information that will allow smooth social functioning. Periods of unrest and uncertainty in societies contribute to "societal information overload," whereby an abundance of information channels can create communication…

  12. Ionospheric data assimilation with thermosphere-ionosphere-electrodynamics general circulation model and GPS-TEC during geomagnetic storm conditions

    Science.gov (United States)

    Chen, C. H.; Lin, C. H.; Matsuo, T.; Chen, W. H.; Lee, I. T.; Liu, J. Y.; Lin, J. T.; Hsu, C. T.

    2016-06-01

    The main purpose of this paper is to investigate the effects of rapid assimilation-forecast cycling on the performance of ionospheric data assimilation during geomagnetic storm conditions. An ensemble Kalman filter software developed by the National Center for Atmospheric Research (NCAR), called Data Assimilation Research Testbed, is applied to assimilate ground-based GPS total electron content (TEC) observations into a theoretical numerical model of the thermosphere and ionosphere (NCAR thermosphere-ionosphere-electrodynamics general circulation model) during the 26 September 2011 geomagnetic storm period. Effects of various assimilation-forecast cycle lengths: 60, 30, and 10 min on the ionospheric forecast are examined by using the global root-mean-squared observation-minus-forecast (OmF) TEC residuals. Substantial reduction in the global OmF for the 10 min assimilation-forecast cycling suggests that a rapid cycling ionospheric data assimilation system can greatly improve the quality of the model forecast during geomagnetic storm conditions. Furthermore, updating the thermospheric state variables in the coupled thermosphere-ionosphere forecast model in the assimilation step is an important factor in improving the trajectory of model forecasting. The shorter assimilation-forecast cycling (10 min in this paper) helps to restrain unrealistic model error growth during the forecast step due to the imbalance among model state variables resulting from an inadequate state update, which in turn leads to a greater forecast accuracy.

  13. Numerical Prediction of Dust. Chapter 10

    Science.gov (United States)

    Benedetti, Angela; Baldasano, J. M.; Basart, S.; Benincasa, F.; Boucher, O.; Brooks, M.; Chen, J. P.; Colarco, P. R.; Gong, S.; Huneeus, N.; Jones, L; Lu, S.; Menut, L.; Mulcahy, J.; Nickovic, S.; Morcrette, J.-J.; Perez, C.; Reid, J. S.; Sekiyama, T. T.; Tanaka, T.; Terradellas, E.; Westphal, D. L.; Zhang, X.-Y.; Zhou, C.-H.

    2013-01-01

    Covers the whole breadth of mineral dust research, from a scientific perspective Presents interdisciplinary work including results from field campaigns, satellite observations, laboratory studies, computer modelling and theoretical studies Explores the role of dust as a player and recorder of environmental change This volume presents state-of-the-art research about mineral dust, including results from field campaigns, satellite observations, laboratory studies, computer modelling and theoretical studies. Dust research is a new, dynamic and fast-growing area of science and due to its multiple roles in the Earth system, dust has become a fascinating topic for many scientific disciplines. Aspects of dust research covered in this book reach from timescales of minutes (as with dust devils, cloud processes, and radiation) to millennia (as with loess formation and oceanic sediments), making dust both a player and recorder of environmental change. The book is structured in four main parts that explore characteristics of dust, the global dust cycle, impacts of dust on the Earth system, and dust as a climate indicator. The chapters in these parts provide a comprehensive, detailed overview of this highly interdisciplinary subject. The contributions presented here cover dust from source to sink and describe all the processes dust particles undergo while travelling through the atmosphere. Chapters explore how dust is lifted and transported, how it affects radiation, clouds, regional circulations, precipitation and chemical processes in the atmosphere, and how it deteriorates air quality. The book explores how dust is removed from the atmosphere by gravitational settling, turbulence or precipitation, how iron contained in dust fertilizes terrestrial and marine ecosystems, and about the role that dust plays in human health. We learn how dust is observed, simulated using computer models and forecast. The book also details the role of dust deposits for climate reconstructions

  14. Hazards of geomagnetic storms

    Science.gov (United States)

    Herzog, D.C.

    1992-01-01

    Geomagnetic storms are large and sometimes rapid fluctuations in the Earth's magnetic field that are related to disturbances on the Sun's surface. Although it is not widely recognized, these transient magnetic disturbances can be a significant hazard to people and property. Many of us know that the intensity of the auroral lights increases during magnetic storms, but few people realize that these storms can also cause massive power outages, interrupt radio communications and satellite operations, increase corrosion in oil and gas pipelines, and lead to spuriously high rejection rates in the manufacture of sensitive electronic equipment. 

  15. Optimized Flood Forecasts Using a Statistical Enemble

    Science.gov (United States)

    Silver, Micha; Fredj, Erick

    2016-04-01

    The method presented here assembles an optimized flood forecast from a set of consecutive WRF-Hydro simulations by applying coefficients which we derive from straightforward statistical procedures. Several government and research institutions that produce climate data offer ensemble forecasts, which merge predictions from different models to gain a more accurate fit to observed data. Existing ensemble forecasts present climate and weather predictions only. In this research we propose a novel approach to constructing hydrological ensembles for flood forecasting. The ensemble flood forecast is created by combining predictions from the same model, but initiated at different times. An operative flood forecasting system, run by the Israeli Hydrological Service, produces flood forecasts twice daily with a 72 hour forecast period. By collating the output from consecutive simulation runs we have access to multiple overlapping forecasts. We then apply two statistical procedures to blend these consecutive forecasts, resulting in a very close fit to observed flood runoff. We first employ cross-correlation with a time lag to determine a time shift for each of the original, consecutive forecasts. This shift corrects for two possible sources of error: slow or fast moving weather fronts in the base climate data; and mis-calibrations of the WRF-Hydro model in determining the rate of flow of surface runoff and in channels. We apply this time shift to all consecutive forecasts, then run a linear regression with the observed runoff data as the dependent variable and all shifted forecasts as the predictor variables. The solution to the linear regression equation is a set of coefficients that corrects the amplitude errors in the forecasts. These resulting regression coefficients are then applied to the consecutive forecasts producing a statistical ensemble which, by design, closely matches the observed runoff. After performing this procedure over many storm events in the Negev region

  16. A stochastic method for convective storm identification,tracking and nowcasting

    Institute of Scientific and Technical Information of China (English)

    Lei Han; Shengxue Fu; Guang Yang; Hongqing Wang; Yongguang Zheng; Yingjing Lin

    2008-01-01

    The convective storm identification,tracking and nowcasting method is one of the important nowcasting methodologies against severe convective weather.In severe convective cases,such as storm shape or rapid velocity changes,existing methods are apt to provide unsatisfied storm identification,tracking and nowcasting results.To overcome these difficulties,this paper proposes a novel approach to identify,track and short-term forecast (nowcast) of convective storms.A mathematical morphology-based storm identification method is adopted which can identify storm cells accurately in a cluster of storms.As for the difficult tracking problem,sequential Monte Carlo (SMC) method is utilized to simplify the tracking process.It is not only inherently suitable for handling complicated splits and mergers,but also capable of handling the case of storm-missing detection.In order to provide more accurate forecast of a storm position,this method takes the advantages of the cross-correlation method.The qualitative and quantitative evaluations show the efficiency and robustness of the proposed approach.

  17. Improved estimates of the European winter wind storm climate and the risk of reinsurance loss

    Science.gov (United States)

    Della-Marta, P. M.; Liniger, M. A.; Appenzeller, C.; Bresch, D. N.; Koellner-Heck, P.; Muccione, V.

    2009-04-01

    Current estimates of the European wind storm climate and their associated losses are often hampered by either relatively short, coarse resolution or inhomogeneous datasets. This study estimates the European wind storm climate using dynamical seasonal-to-decadal (s2d) climate forecasts from the European Centre for Medium-Range Weather Forecasts (ECMWF). The current s2d models' have limited predictive skill of European storminess, making the ensemble forecasts ergodic samples on which to build pseudo climates of 310 to 396 years in length. Extended winter (ONDJFMA) wind storm climatologies are created using a scalar extreme wind index considering only data above a high threshold. The method identifes between 2331 and 2471 wind storms using s2d data and 380 wind storms in ERA-40. Classical extreme value analysis (EVA) techniques are used to determine the wind storm climatologies. We suggest that the ERA-40 climatology, by virtue of its length, limiting form, and the fitting method, overestimates the return period (RP) of wind storms with RPs between 10-300 years and underestimates the return period of wind storms with RPs greater than 300 years. A 50 year event in ERA-40 is approximately a 33 year event using s2d. The largest influence on ERA-40 RP uncertainties is the sampling variability associated with only 45 seasons of storms. The climatologies are linked to the Swiss Reinsurance Company (Swiss Re) European wind storm loss model. New estimates of the risk of loss are compared with those from historical and stochastically generated wind storm fields used by Swiss Re. The resulting loss-frequency relationship matches well with the two independently modelled estimates and clearly demonstrates the added value by using alternative data and methods, as proposed in this study, to estimate the RP of high RP losses.

  18. Saharan dust events measured at Camaguey, Cuba

    Science.gov (United States)

    Antuna, J.; Estevan, R.; Barja, B.

    2012-12-01

    Using AERONET level 2.0 dataset from Camagüey, Cuba, Saharan Dust events have been measured from 2009 to the present. The sunphotometer, operated by GOAC in cooperation with RIMA (Red Iberica de Medicion de Aerosoles) has been also contributing to AERONET. Five Saharan dust events AOD measured in July 2009 have been compared with Spatio-temporal coincident MODIS (both from Aqua and Terra instruments) measurements of AOD. Also the SKIRON model AOD forecasts for the same period over Camagüey were compared with local measurements. The daily average values of the sunphotometer measured AOD and modeled forecasted AOD show a better agreement than the rest of the combinations of AOD selection criteria tested, but still notable differences are present. The lack of background aerosols AOD in the forecast produces additional differences in the absence of Saharan dust. In the case of the long range transport of Saharan aerosols the forecasted AOD values are higher than the measured ones. The differences daily mean sunphotometer AOD and the daily mean areal MODIS (both Terra and Aqua) AOD are lower than the differences between the daily maximum sunphotometer AOD and the daily areal maximum MODIS (both from Terra and Aqua) AOD. The mean areal AOD MODIS values (both for Terra and Aqua) underestimates the high aerosols concentrations and overestimates the lower ones, measured by the sunphotometer. New research is underway, covering the 2009 and 2010 Saharan dust events. Preliminary results are shown.

  19. Potential Seasonal Predictability for Winter Storms over Europe

    Science.gov (United States)

    Wild, Simon; Befort, Daniel J.; Leckebusch, Gregor C.

    2017-04-01

    Reliable seasonal forecasts of strong extra-tropical cyclones and windstorms would have great social and economical benefits, as these events are the most costly natural hazards over Europe. In a previous study we have shown good agreement of spatial climatological distributions of extra-tropical cyclones and wind storms in state-of-the-art multi-member seasonal prediction systems with reanalysis. We also found significant seasonal prediction skill of extra-tropical cyclones and windstorms affecting numerous European countries. We continue this research by investigating the mechanisms and precursor conditions (primarily over the North Atlantic) on a seasonal time scale leading to enhanced extra-tropical cyclone activity and winter storm frequency over Europe. Our results regarding mechanisms show that an increased surface temperature gradient at the western edge of the North Atlantic can be related to enhanced winter storm frequency further downstream causing for example a greater number of storms over the British Isles, as observed in winter 2013-14.The so-called "Horseshoe Index", a SST tripole anomaly pattern over the North Atlantic in the summer months can also cause a higher number of winter storms over Europe in the subsequent winter. We will show results of AMIP-type sensitivity experiments using an AGCM (ECHAM5), supporting this hypothesis. Finally we will analyse whether existing seasonal forecast systems are able to capture these identified mechanisms and precursor conditions affecting the models' seasonal prediction skill.

  20. Storm Data Publication

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — 'Storm Data and Unusual Weather Phenomena' is a monthly publication containing a chronological listing, by state, of hurricanes, tornadoes, thunderstorms, hail,...

  1. Application of mesoscale model-generated sounding in Beijing local rain storm forecasting%中尺度模式探空资料在北京局地暴雨预报中的应用

    Institute of Scientific and Technical Information of China (English)

    张文龙; 范水勇; 陈敏

    2012-01-01

    结合北京局地暴雨特点,重点分析北京两次局地强暴雨过程的中尺度模式探空资料的特征与应用,同时简单讨论模式探空与降水量预报可能存在不协调的原因。结果表明:1)有利于北京局地暴雨发生的模式探空资料的主要特征是:对流层低层850 hPa以下水汽含量较充足,层结温度线与干绝热线近于平行,地面温度高(大于31℃);对流层中高层650 hPa以上相对冷干,对流层中低层800—600 hPa存在有利于深对流发生发展的饱和或准饱和层。2)模式探空资料可以正确反映强降水时间分布、降水性质及不同性质降水之间转换等,由于模式自身存在的协调性问题,在局地暴雨预报中有必要重视对模式探空资料的分析。3)上述结论是在两次暴雨过程分析的基础上得到的,今后仍需通过更多个例来进一步考察。%According to the features of the local rainstorm in Beijing,this paper mainly analyzed the features and application of mesoscale model-generated sounding of two cases of local rainstorm in Beijing,also a preliminary discussion of the factors which could result in the disagreement of implication between sounding and rainfall forecast was given.The results show the following:(1) the features of the mesoscale model-generated sounding implying the rainstorm are as follows.The troposphere in lower level contains sufficient moisture to support the deep convections.The stratification curve is parallel to the dry adiabat with ground temperature warmer than 31 ℃,and it is relatively dry and cold above 650 hPa.There is a saturation or quasi-saturation level between the 800-600 hPa in the middle and lower troposphere,which is beneficial for occurrence and development of deep convection.2) The model-generated soundings can provide a useful implication of the temporal distribution of rainstorm,the characteristics of the rain,and the transition from convectional rain to

  2. Dust Accumulation and Cleaning of the MER Spirit Solar Array

    Science.gov (United States)

    Herman, J. A.; Lemmon, M. T.; Johnson, J. R.; Cantor, B. A.; Stella, P. M.; Chin, K. B.; Wood, E. G.

    2012-12-01

    The solar array of the NASA Mars Exploration Rover (MER) Spirit was expected to accumulate so much dust after ninety Martian days (sols) that it could no longer provide enough energy to guarantee continued surface operations. Instead, due in part to low dust accumulation rates and numerous dust cleaning events, Spirit carried out surface operations for over 2200 sols (over three Mars years). During this time period, the rover experienced four Martian winters and several dust storms. Because the sources of solar energy loss are known, the solar array energy output offers a tool to quantitatively estimate the loading and aeolian removal of dust from the solar array each sol. We will discuss the accumulation of dust on the solar panels as a proxy for dust movement at Gusev Crater over the course of the entire mission.

  3. Dust Accumulation and Cleaning of the MER Opportunity Solar Array

    Science.gov (United States)

    Herman, J.

    2015-12-01

    The solar array of the NASA Mars Exploration Rover (MER) Opportunity was expected to accumulate a sufficient quantity of dust after ninety Martian days (sols) such that it could no longer provide enough energy to guarantee continued surface operations. Instead, due in part to low dust accumulation rates and numerous dust cleaning events, Opportunity continues to operate on the Martian surface for over 4000 sols (over six Mars years). During this time period, the rover experienced six Martian winters and several dust storms. Because the sources of solar energy loss are known, the solar array energy output offers a method to scientifically estimate the loading and aeolian removal of dust from the solar array each sol. We will discuss the accumulation of dust on the solar panels as a proxy for dust movement at Meridiani Planum over the course of the entire mission to date.

  4. The influence of the meteorological forcing data on the reconstructions of historical storms in the Black Sea

    OpenAIRE

    Galabov, Vasko; Kortcheva, Anna

    2013-01-01

    The present article is a study of the applicability of different sources of meteorological forcing for the coastal wave and storm surge models, which provide the operational marine forecasts for the coastal early warning systems (EWS) and are used for reconstructions of historical storms. The reconstruction of historical storms is one of the approaches to the natural coastal hazard vulnerability assessment. We evaluate the importance of the input meteorological information for the mentioned t...

  5. Numerical investigation of the coagulation mixing between dust and hygroscopic aerosol particles and its impacts

    National Research Council Canada - National Science Library

    Tsai, I‐Chun; Chen, Jen‐Ping; Lin, Yi‐Chiu; Chou, Charles Chung‐Kuang; Chen, Wei‐Nai

    2015-01-01

    A statistical‐numerical aerosol parameterization was incorporated into the Community Multiscale Air Quality modeling system to study the coagulation mixing process focusing on a dust storm event that occurred over East Asia...

  6. The case for a southeastern Australian Dust Bowl, 1895-1945

    Science.gov (United States)

    Cattle, Stephen R.

    2016-06-01

    Australia has an anecdotal history of severe wind erosion and dust storm activity, but there has been no lasting public perception of periods of extreme dust storm activity in this country, such as that developed in the USA following the Dust Bowl of the 1930s. Newspaper accounts of droughts and dust storms in southeastern (SE) Australia between 1895 and 1945 suggest that, at various times, the scale of these events was comparable to those experienced in the USA Dust Bowl. During this 50-year period, average annual rainfall values in this region were substantially below long-term averages, air temperatures were distinctly warmer, marginal lands were actively cropped and grazed, and rabbits were a burgeoning grazing pest. From the beginning of the Federation Drought of 1895-1902, dust storm activity increased markedly, with the downwind coastal cities of Sydney and Melbourne experiencing dust hazes, dust storms and falls of red rain relatively regularly. Between 1935 and 1945, Sydney and Melbourne received ten and nine long-distance dust events, respectively, with the years of 1938 and 1944/45 being the most intensely dusty. Entire topsoil horizons were blown away, sand drift was extreme, and crops and sheep flocks were destroyed. Although these periods of extreme dust storm activity were not as sustained as those experienced in the USA in the mid-1930s, there is a strong case to support the contention that SE Australia experienced its own extended, somewhat episodic version of a Dust Bowl, with a similar combination of causal factors and landscape effects.

  7. Dust Mite Allergy

    Science.gov (United States)

    Dust mite allergy Overview By Mayo Clinic Staff Dust mite allergy is an allergic reaction to tiny bugs that commonly live in house dust. Signs of dust mite allergy include those common to hay fever, such as ...

  8. A Numerical Simulation (Study) of a Strong West Coast December 2014 Winter Storm

    Science.gov (United States)

    Smelser, I.; Xu, L.; Amerault, C. M.; Baker, N. L.; Satterfield, E.; Chua, B.

    2016-12-01

    From December 10 through December 13, 2014, a powerful winter storm swept across the western US coastal states bringing widespread power outages, numerous downed trees and power lines, heavy rains, flooding and even a tornado in the Los Angeles basin. This windstorm was the strongest since October 2009, and was similar to classic wind storms such as the 1962 Columbus Day Storm (Read, 2015).The storm started developing over the Pacific Ocean north of Hawaii on Nov. 30, and formed an atmospheric river that eventually stretched from Hawaii to the west coast. The storm initially hit the Pacific Northwest on Dec. 9th and then split. The highest precipitation amounts started in British Colombia and moved south along the coast. By the Dec. 11th, the highest precipitation amounts were near San Francisco (CA). The peak wind gust (14.4 ms-1) for Monterey (CA) occurred at 1116Z on Dec. 11th while the heaviest 6-hr precipitation (42.9 mm) occurred between 18Z on Dec. 11th to 00Z on Dec. 12th. By Dec. 12th, the storm was centered over Southern California.This storm was poorly forecast by many operational NWP models even 2-3 days in advance (Mass, 2014). The NCEP Global Forecast System (GFS) showed considerably variability between successive model runs, and significant differences existed between Environment Canada, UK Met Office and ECMWF model forecasts. To study this extreme weather event, we used the Navy global (NAVGEM) and mesoscale (COAMPS®) NWP models, and compared the resulting forecasts to observations, satellite imagery and ECMWF (TIGGE) forecasts. NAVGEM, with Hybrid 4DVar, was run with a resolution of 31 km, and generated the boundary conditions for COAMPS® 4DVar and forecasts, that were run with triple-nested grids of 27, 9, and 3 km. The MesoWest data from the University of Utah were used for forecast verification, and to locate the times of highest precipitation and wind speed for different points along the coast. Both the online API and the python module were

  9. Applications of Electrified Dust and Dust Devil Electrodynamics to Martian Atmospheric Electricity

    Science.gov (United States)

    Harrison, R. G.; Barth, E.; Esposito, F.; Merrison, J.; Montmessin, F.; Aplin, K. L.; Borlina, C.; Berthelier, J. J.; Déprez, G.; Farrell, W. M.; Houghton, I. M. P.; Renno, N. O.; Nicoll, K. A.; Tripathi, S. N.; Zimmerman, M.

    2016-04-01

    Atmospheric transport and suspension of dust frequently brings electrification, which may be substantial. Electric fields of 10 kV m-1 to 100 kV m-1 have been observed at the surface beneath suspended dust in the terrestrial atmosphere, and some electrification has been observed to persist in dust at levels to 5 km, as well as in volcanic plumes. The interaction between individual particles which causes the electrification is incompletely understood, and multiple processes are thought to be acting. A variation in particle charge with particle size, and the effect of gravitational separation explains to, some extent, the charge structures observed in terrestrial dust storms. More extensive flow-based modelling demonstrates that bulk electric fields in excess of 10 kV m-1 can be obtained rapidly (in less than 10 s) from rotating dust systems (dust devils) and that terrestrial breakdown fields can be obtained. Modelled profiles of electrical conductivity in the Martian atmosphere suggest the possibility of dust electrification, and dust devils have been suggested as a mechanism of charge separation able to maintain current flow between one region of the atmosphere and another, through a global circuit. Fundamental new understanding of Martian atmospheric electricity will result from the ExoMars mission, which carries the DREAMS (Dust characterization, Risk Assessment, and Environment Analyser on the Martian Surface)—MicroARES (Atmospheric Radiation and Electricity Sensor) instrumentation to Mars in 2016 for the first in situ electrical measurements.

  10. Applications of Electrified Dust and Dust Devil Electrodynamics to Martian Atmospheric Electricity

    Science.gov (United States)

    Harrison, R. G.; Barth, E.; Esposito, F.; Merrison, J.; Montmessin, F.; Aplin, K. L.; Borlina, C.; Berthelier, J. J.; Déprez, G.; Farrell, W. M.; Houghton, I. M. P.; Renno, N. O.; Nicoll, K. A.; Tripathi, S. N.; Zimmerman, M.

    2016-11-01

    Atmospheric transport and suspension of dust frequently brings electrification, which may be substantial. Electric fields of 10 kV m-1 to 100 kV m-1 have been observed at the surface beneath suspended dust in the terrestrial atmosphere, and some electrification has been observed to persist in dust at levels to 5 km, as well as in volcanic plumes. The interaction between individual particles which causes the electrification is incompletely understood, and multiple processes are thought to be acting. A variation in particle charge with particle size, and the effect of gravitational separation explains to, some extent, the charge structures observed in terrestrial dust storms. More extensive flow-based modelling demonstrates that bulk electric fields in excess of 10 kV m-1 can be obtained rapidly (in less than 10 s) from rotating dust systems (dust devils) and that terrestrial breakdown fields can be obtained. Modelled profiles of electrical conductivity in the Martian atmosphere suggest the possibility of dust electrification, and dust devils have been suggested as a mechanism of charge separation able to maintain current flow between one region of the atmosphere and another, through a global circuit. Fundamental new understanding of Martian atmospheric electricity will result from the ExoMars mission, which carries the DREAMS (Dust characterization, Risk Assessment, and Environment Analyser on the Martian Surface)—MicroARES ( Atmospheric Radiation and Electricity Sensor) instrumentation to Mars in 2016 for the first in situ electrical measurements.

  11. Dust: Small-scale processes with global consequences

    Science.gov (United States)

    Okin, G.S.; Bullard, J.E.; Reynolds, R.L.; Ballantine, J.-A.C.; Schepanski, K.; Todd, M.C.; Belnap, J.; Baddock, M.C.; Gill, T.E.; Miller, M.E.

    2011-01-01

    Desert dust, both modern and ancient, is a critical component of the Earth system. Atmospheric dust has important effects on climate by changing the atmospheric radiation budget, while deposited dust influences biogeochemical cycles in the oceans and on land. Dust deposited on snow and ice decreases its albedo, allowing more light to be trapped at the surface, thus increasing the rate of melt and influencing energy budgets and river discharge. In the human realm, dust contributes to the transport of allergens and pathogens and when inhaled can cause or aggravate respiratory diseases. Dust storms also represent a significant hazard to road and air travel. Because it affects so many Earth processes, dust is studied from a variety of perspectives and at multiple scales, with various disciplines examining emissions for different purposes using disparate strategies. Thus, the range of objectives in studying dust, as well as experimental approaches and results, has not yet been systematically integrated. Key research questions surrounding the production and sources of dust could benefit from improved collaboration among different research communities. These questions involve the origins of dust, factors that influence dust production and emission, and methods through which dust can be monitored. ?? Author(s) 2011.

  12. Dust emission: small-scale processes with global consequences

    Science.gov (United States)

    Okin, Gregory S.; Bullard, Joanna E.; Reynolds, Richard L.; Ballantine, John-Andrew C.; Schepanski, Kerstin; Todd, Martin C.; Belnap, Jayne; Baddock, Matthew C.; Gill, Thomas E.; Miller, Mark E.

    2011-01-01

    Desert dust, both modern and ancient, is a critical component of the Earth system. Atmospheric dust has important effects on climate by changing the atmospheric radiation budget, while deposited dust influences biogeochemical cycles in the oceans and on land. Dust deposited on snow and ice decreases its albedo, allowing more light to be trapped at the surface, thus increasing the rate of melt and influencing energy budgets and river discharge. In the human realm, dust contributes to the transport of allergens and pathogens and when inhaled can cause or aggravate respiratory diseases. Dust storms also represent a significant hazard to road and air travel. Because it affects so many Earth processes, dust is studied from a variety of perspectives and at multiple scales, with various disciplines examining emissions for different purposes using disparate strategies. Thus, the range of objectives in studying dust, as well as experimental approaches and results, has not yet been systematically integrated. Key research questions surrounding the production and sources of dust could benefit from improved collaboration among different research communities. These questions involve the origins of dust, factors that influence dust production and emission, and methods through which dust can be monitored.

  13. Ionospheric forecasts for the European region for space weather applications

    Directory of Open Access Journals (Sweden)

    Tsagouri Ioanna

    2015-01-01

    Full Text Available This paper discusses recent advances in the implementation and validation of the Solar Wind driven autoregression model for Ionospheric short-term Forecast (SWIF that is running in the European Digital upper Atmosphere Server (DIAS to release ionospheric forecasting products for the European region. The upgraded implementation plan expands SWIF’s capabilities in the high latitude ionosphere while the extensive validation tests in the two solar cycles 23 and 24 allow the comprehensive analysis of the model’s performance in all terms. Focusing on disturbed conditions, the results demonstrate that SWIF’s alert detection algorithm forecasts the occurrence of ionospheric storm time disturbances with probability of detection up to 98% under intense geomagnetic storm conditions and up to 63% when storms of moderate intensity are also considered. The forecasts show relative improvement over climatology of about 30% in middle-to-low and high latitudes and 40% in middle-to-high latitudes. This indicates that SWIF is able to capture on average more than one third (35% of the storm-associated ionospheric disturbances. Regarding the accuracy, the averaged mean relative error during storm conditions usually ranges around 20% in middle-to-low and high latitudes and 24% in the middle-to-high latitudes. Our analysis shows clearly that SWIF alert criteria were designed to effectively anticipate the ionospheric storm time effects that occurred under specific interplanetary conditions, e.g., cloud Interplanetary Coronal Mass Ejections (ICMEs and/or associated sheaths. The results provide valuable input in advancing our ability in predicting the space weather effects in the ionosphere for future developments, and further work is proposed to enhance the model forecasting efficiency to support operational applications.

  14. Discharge Water Quality Models of Storm Runoff in a Catchment

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The relationships between the water qualities of nitrogen and phosphorous contents in the discharge water and the discharge of storm runoff of an experimental catchment including terraced paddy field are analyzed based on experiment results of the catchment. By summarizing the currently related research on water quality models, the water quality models of different components of storm runoff of the catchment are presented and verified with the experiment data of water quality analyses and the corresponding discharge of the storm runoffs during 3 storms. Through estimating the specific discharge of storm runoff, the specific load of different components of nitrogen and phosphorus in the discharge water of the catchment can be forecasted by the models. It is found that the mathematical methods of linear regression are very useful for analysis of the relationship between the concentrations of nitrogen and phosphorus and the water discharge of storm runoff. It is also found that the most content of the nitrogen (75%) in the discharge water is organic, while half of the content (49%) of phosphorus in the discharge water is inorganic.

  15. kwmc Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  16. kont Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  17. kcrg Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  18. kjac Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  19. krdu Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  20. kiwd Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  1. krbl Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  2. kssf Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  3. ksaw Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  4. kmot Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  5. kiso Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  6. kgck Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  7. kcvg Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  8. pafa Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  9. kcrq Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  10. ksun Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  11. kpia Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  12. krow Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  13. kbtv Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  14. kbke Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  15. kbpt Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  16. kact Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  17. kavl Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  18. kbur Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  19. krsw Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  20. klnd Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  1. kpuw Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  2. kbis Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  3. kcmx Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  4. kipt Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  5. kteb Terminal Aerodrome Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation. TAFs are...

  6. kely Terminal Aerodrome Forecast

    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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