WorldWideScience

Sample records for hurricane wind retrievals

  1. Hurricane Imaging Radiometer (HIRAD) Wind Speed Retrieval Assessment with Dropsondes

    Science.gov (United States)

    Cecil, Daniel J.; Biswas, Sayak K.

    2017-01-01

    Map surface wind speed over wide swath (approximately 50-60 km, for aircraft greater than FL600) in hurricanes. Provide research data for understanding hurricane structure, and intensity change. Enable improved forecasts, warnings, and decision support.

  2. Hurricane Imaging Radiometer Wind Speed and Rain Rate Retrievals during the 2010 GRIP Flight Experiment

    Science.gov (United States)

    Sahawneh, Saleem; Farrar, Spencer; Johnson, James; Jones, W. Linwood; Roberts, Jason; Biswas, Sayak; Cecil, Daniel

    2014-01-01

    Microwave remote sensing observations of hurricanes, from NOAA and USAF hurricane surveillance aircraft, provide vital data for hurricane research and operations, for forecasting the intensity and track of tropical storms. The current operational standard for hurricane wind speed and rain rate measurements is the Stepped Frequency Microwave Radiometer (SFMR), which is a nadir viewing passive microwave airborne remote sensor. The Hurricane Imaging Radiometer, HIRAD, will extend the nadir viewing SFMR capability to provide wide swath images of wind speed and rain rate, while flying on a high altitude aircraft. HIRAD was first flown in the Genesis and Rapid Intensification Processes, GRIP, NASA hurricane field experiment in 2010. This paper reports on geophysical retrieval results and provides hurricane images from GRIP flights. An overview of the HIRAD instrument and the radiative transfer theory based, wind speed/rain rate retrieval algorithm is included. Results are presented for hurricane wind speed and rain rate for Earl and Karl, with comparison to collocated SFMR retrievals and WP3D Fuselage Radar images for validation purposes.

  3. Wind Retrieval Algorithms for the IWRAP and HIWRAP Airborne Doppler Radars with Applications to Hurricanes

    Science.gov (United States)

    Guimond, Stephen Richard; Tian, Lin; Heymsfield, Gerald M.; Frasier, Stephen J.

    2013-01-01

    Algorithms for the retrieval of atmospheric winds in precipitating systems from downward-pointing, conically-scanning airborne Doppler radars are presented. The focus in the paper is on two radars: the Imaging Wind and Rain Airborne Profiler(IWRAP) and the High-altitude IWRAP (HIWRAP). The IWRAP is a dual-frequency (Cand Ku band), multi-beam (incidence angles of 30 50) system that flies on the NOAAWP-3D aircraft at altitudes of 2-4 km. The HIWRAP is a dual-frequency (Ku and Kaband), dual-beam (incidence angles of 30 and 40) system that flies on the NASA Global Hawk aircraft at altitudes of 18-20 km. Retrievals of the three Cartesian wind components over the entire radar sampling volume are described, which can be determined using either a traditional least squares or variational solution procedure. The random errors in the retrievals are evaluated using both an error propagation analysis and a numerical simulation of a hurricane. These analyses show that the vertical and along-track wind errors have strong across-track dependence with values of 0.25 m s-1 at nadir to 2.0 m s-1 and 1.0 m s-1 at the swath edges, respectively. The across-track wind errors also have across-track structure and are on average, 3.0 3.5 m s-1 or 10 of the hurricane wind speed. For typical rotated figure four flight patterns through hurricanes, the zonal and meridional wind speed errors are 2 3 m s-1.Examples of measured data retrievals from IWRAP during an eyewall replacement cycle in Hurricane Isabel (2003) and from HIWRAP during the development of Tropical Storm Matthew (2010) are shown.

  4. Retrieval of sea surface winds under hurricane conditions from GNSS-R observations

    Institute of Scientific and Technical Information of China (English)

    JING Cheng; YANG Xiaofeng; MA Wentao; YU Yang; DONG Di; LI Ziwei; XU Cong

    2016-01-01

    Reflected signals from global navigation satellite systems (GNSSs) have been widely acknowledged as an important remote sensing tool for retrieving sea surface wind speeds. The power of GNSS reflectometry (GNSS-R) signals can be mapped in delay chips and Doppler frequency space to generate delay Doppler power maps (DDMs), whose characteristics are related to sea surface roughness and can be used to retrieve wind speeds. However, the bistatic radar cross section (BRCS), which is strongly related to the sea surface roughness, is extensively used in radar. Therefore, a bistatic radar cross section (BRCS) map with a modified BRCS equation in a GNSS-R application is introduced. On the BRCS map, three observables are proposed to represent the sea surface roughness to establish a relationship with the sea surface wind speed. Airborne Hurricane Dennis (2005) GNSS-R data are then used. More than 16 000 BRCS maps are generated to establish GMFs of the three observables. Finally, the proposed model and classic one-dimensional delay waveform (DW) matching methods are compared, and the proposed model demonstrates a better performance for the high wind speed retrievals.

  5. Retrieving hurricane wind speeds using cross-polarization C-band measurements

    NARCIS (Netherlands)

    Van Zadelhoff, G.J.; Stoffelen, A.; Vachon, P.W.; Wolfe, J.; Horstmann, J.; Belmonte Rivas, M.

    2014-01-01

    Hurricane-force wind speeds can have a large societal impact and in this paper microwave C-band cross-polarized (VH) signals are investigated to assess if they can be used to derive extreme wind-speed conditions. European satellite scatterometers have excellent hurricane penetration capability at C-

  6. Retrieving hurricane wind speeds using cross-polarization C-band measurements

    NARCIS (Netherlands)

    Van Zadelhoff, G.J.; Stoffelen, A.; Vachon, P.W.; Wolfe, J.; Horstmann, J.; Belmonte Rivas, M.

    2014-01-01

    Hurricane-force wind speeds can have a large societal impact and in this paper microwave C-band cross-polarized (VH) signals are investigated to assess if they can be used to derive extreme wind-speed conditions. European satellite scatterometers have excellent hurricane penetration capability at C-

  7. Retrieving hurricane wind speeds using cross-polarization C-band measurements

    NARCIS (Netherlands)

    Van Zadelhoff, G.J.; Stoffelen, A.; Vachon, P.W.; Wolfe, J.; Horstmann, J.; Belmonte Rivas, M.

    2014-01-01

    Hurricane-force wind speeds can have a large societal impact and in this paper microwave C-band cross-polarized (VH) signals are investigated to assess if they can be used to derive extreme wind-speed conditions. European satellite scatterometers have excellent hurricane penetration capability at

  8. Hurricane Wind Speed Estimation Using WindSat 6 and 10 GHz Brightness Temperatures

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    2016-08-01

    Full Text Available The realistic and accurate estimation of hurricane intensity is highly desired in many scientific and operational applications. With the advance of passive microwave polarimetry, an alternative opportunity for retrieving wind speed in hurricanes has become available. A wind speed retrieval algorithm for wind speeds above 20 m/s in hurricanes has been developed by using the 6.8 and 10.7 GHz vertically and horizontally polarized brightness temperatures of WindSat. The WindSat measurements for 15 category 4 and category 5 hurricanes from 2003 to 2010 and the corresponding H*wind analysis data are used to develop and validate the retrieval model. In addition, the retrieved wind speeds are also compared to the Remote Sensing Systems (RSS global all-weather product and stepped-frequency microwave radiometer (SFMR measurements. The statistical results show that the mean bias and the overall root-mean-square (RMS difference of the retrieved wind speeds with respect to the H*wind analysis data are 0.04 and 2.75 m/s, respectively, which provides an encouraging result for retrieving hurricane wind speeds over the ocean surface. The retrieved wind speeds show good agreement with the SFMR measurements. Two case studies demonstrate that the mean bias and RMS difference are 0.79 m/s and 1.79 m/s for hurricane Rita-1 and 0.63 m/s and 2.38 m/s for hurricane Rita-2, respectively. In general, the wind speed retrieval accuracy of the new model in hurricanes ranges from 2.0 m/s in light rain to 3.9 m/s in heavy rain.

  9. Hurricane Katrina Wind Investigation Report

    Energy Technology Data Exchange (ETDEWEB)

    Desjarlais, A. O.

    2007-08-15

    This investigation of roof damage caused by Hurricane Katrina is a joint effort of the Roofing Industry Committee on Weather Issues, Inc. (RICOWI) and the Oak Ridge National Laboratory/U.S. Department of Energy (ORNL/DOE). The Wind Investigation Program (WIP) was initiated in 1996. Hurricane damage that met the criteria of a major windstorm event did not materialize until Hurricanes Charley and Ivan occurred in August 2004. Hurricane Katrina presented a third opportunity for a wind damage investigation in August 29, 2005. The major objectives of the WIP are as follows: (1) to investigate the field performance of roofing assemblies after major wind events; (2) to factually describe roofing assembly performance and modes of failure; and (3) to formally report results of the investigations and damage modes for substantial wind speeds The goal of the WIP is to perform unbiased, detailed investigations by credible personnel from the roofing industry, the insurance industry, and academia. Data from these investigations will, it is hoped, lead to overall improvement in roofing products, systems, roofing application, and durability and a reduction in losses, which may lead to lower overall costs to the public. This report documents the results of an extensive and well-planned investigative effort. The following program changes were implemented as a result of the lessons learned during the Hurricane Charley and Ivan investigations: (1) A logistics team was deployed to damage areas immediately following landfall; (2) Aerial surveillance--imperative to target wind damage areas--was conducted; (3) Investigation teams were in place within 8 days; (4) Teams collected more detailed data; and (5) Teams took improved photographs and completed more detailed photo logs. Participating associations reviewed the results and lessons learned from the previous investigations and many have taken the following actions: (1) Moved forward with recommendations for new installation procedures

  10. Hurricane Katrina Wind Investigation Report

    Energy Technology Data Exchange (ETDEWEB)

    Desjarlais, A. O.

    2007-08-15

    This investigation of roof damage caused by Hurricane Katrina is a joint effort of the Roofing Industry Committee on Weather Issues, Inc. (RICOWI) and the Oak Ridge National Laboratory/U.S. Department of Energy (ORNL/DOE). The Wind Investigation Program (WIP) was initiated in 1996. Hurricane damage that met the criteria of a major windstorm event did not materialize until Hurricanes Charley and Ivan occurred in August 2004. Hurricane Katrina presented a third opportunity for a wind damage investigation in August 29, 2005. The major objectives of the WIP are as follows: (1) to investigate the field performance of roofing assemblies after major wind events; (2) to factually describe roofing assembly performance and modes of failure; and (3) to formally report results of the investigations and damage modes for substantial wind speeds The goal of the WIP is to perform unbiased, detailed investigations by credible personnel from the roofing industry, the insurance industry, and academia. Data from these investigations will, it is hoped, lead to overall improvement in roofing products, systems, roofing application, and durability and a reduction in losses, which may lead to lower overall costs to the public. This report documents the results of an extensive and well-planned investigative effort. The following program changes were implemented as a result of the lessons learned during the Hurricane Charley and Ivan investigations: (1) A logistics team was deployed to damage areas immediately following landfall; (2) Aerial surveillance--imperative to target wind damage areas--was conducted; (3) Investigation teams were in place within 8 days; (4) Teams collected more detailed data; and (5) Teams took improved photographs and completed more detailed photo logs. Participating associations reviewed the results and lessons learned from the previous investigations and many have taken the following actions: (1) Moved forward with recommendations for new installation procedures

  11. Ocean Surface Wind Speed of Hurricane Helene Observed by SAR

    DEFF Research Database (Denmark)

    Xu, Qing; Cheng, Yongcun; Li, Xiaofeng

    2011-01-01

    The hurricanes can be detected by many remote sensors, but synthetic aperture radar (SAR) can yield high-resolution (sub-kilometer) and low-level wind information that cannot be seen below the cloud by other sensors. In this paper, an assessment of SAR capability of monitoring high-resolution hur......The hurricanes can be detected by many remote sensors, but synthetic aperture radar (SAR) can yield high-resolution (sub-kilometer) and low-level wind information that cannot be seen below the cloud by other sensors. In this paper, an assessment of SAR capability of monitoring high......-resolution hurricane was conducted. A case study was carried out to retrieve ocean surface wind field from C-band RADARSAT-1 SAR image which captured the structure of hurricane Helene over the Atlantic Ocean on 20 September, 2006. With wind direction from the outputs of U.S. Navy Operational Global Atmospheric...... CIWRAP models have been tested to extract wind speed from SAR data. The SAR retrieved ocean surface winds were compared to the aircraft wind speed observations from stepped frequency microwave radiometer (SFMR). The results show the capability of hurricane wind monitoring by SAR....

  12. Remote Sensing of Sea Surface Wind of Hurricane Michael by GPS Reflected Signals

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this paper, the propagating geometry and the waveform of the GPS reflected signals are expatiated in detail. Furthermore, the principle and the method of retrieving sea surface wind are presented. In order to test the feasibility of retrieval, the experiment data obtained by NASA in Hurricane Michael are used. The result shows that the retrieval accuracy of wind speed is about 2 m/s.

  13. Wind and waves in extreme hurricanes

    NARCIS (Netherlands)

    Holthuijsen, L.H.; Powell, M.D.; Pietrzak, J.D.

    2012-01-01

    Waves breaking at the ocean surface are important to the dynamical, chemical and biological processes at the air-sea interface. The traditional view is that the white capping and aero-dynamical surface roughness increase with wind speed up to a limiting value. This view is fundamental to hurricane

  14. Wind and waves in extreme hurricanes

    NARCIS (Netherlands)

    Holthuijsen, L.H.; Powell, M.D.; Pietrzak, J.D.

    2012-01-01

    Waves breaking at the ocean surface are important to the dynamical, chemical and biological processes at the air-sea interface. The traditional view is that the white capping and aero-dynamical surface roughness increase with wind speed up to a limiting value. This view is fundamental to hurricane f

  15. Wind and waves in extreme hurricanes

    NARCIS (Netherlands)

    Holthuijsen, L.H.; Powell, M.D.; Pietrzak, J.D.

    2012-01-01

    Waves breaking at the ocean surface are important to the dynamical, chemical and biological processes at the air-sea interface. The traditional view is that the white capping and aero-dynamical surface roughness increase with wind speed up to a limiting value. This view is fundamental to hurricane f

  16. Elements of extreme wind modeling for hurricanes

    DEFF Research Database (Denmark)

    Larsen, Søren Ejling; Ejsing Jørgensen, Hans; Kelly, Mark C.;

    The report summarizes characteristics of the winds associated with Tropical Cyclones (Hurricanes, Typhoons). It has been conducted by the authors across several years, from 2012-2015, to identify the processes and aspects that one should consider when building at useful computer support system...

  17. Wind Retrieval using Marine Radars

    Science.gov (United States)

    2011-09-30

    Interaction (HiRes) DRI the NATO Undersea Research Center ( NURC ) wants to develop and validate methodologies to retrieve wind field parameters from X-band...marine radar. The main parameters NURC will focus on are the mean surface wind vector as well as the wind gusts in vicinity of the measurement platform

  18. A Non-MLE Approach for Satellite Scatterometer Wind Vector Retrievals in Tropical Cyclones

    Directory of Open Access Journals (Sweden)

    Suleiman Alsweiss

    2014-05-01

    Full Text Available Satellite microwave scatterometers are the principal source of global synoptic-scale ocean vector wind (OVW measurements for a number of scientific and operational oceanic wind applications. However, for extreme wind events such as tropical cyclones, their performance is significantly degraded. This paper presents a novel OVW retrieval algorithm for tropical cyclones which improves the accuracy of scatterometer based ocean surface winds when compared to low-flying aircraft with in-situ and remotely sensed observations. Unlike the traditional maximum likelihood estimation (MLE wind vector retrieval technique, this new approach sequentially estimates scalar wind directions and wind speeds. A detailed description of the algorithm is provided along with results for ten QuikSCAT hurricane overpasses (from 2003–2008 to evaluate the performance of the new algorithm. Results are compared with independent surface wind analyses from the National Oceanic and Atmospheric Administration (NOAA Hurricane Research Division’s H*Wind surface analyses and with the corresponding SeaWinds Project’s L2B-12.5 km OVW products. They demonstrate that the proposed algorithm extends the SeaWinds capability to retrieve wind speeds beyond the current range of approximately 35 m/s (minimal hurricane category-1 with improved wind direction accuracy, making this new approach a potential candidate for current and future conically scanning scatterometer wind retrieval algorithms.

  19. Quantifying the hurricane catastrophe risk to offshore wind power.

    Science.gov (United States)

    Rose, Stephen; Jaramillo, Paulina; Small, Mitchell J; Apt, Jay

    2013-12-01

    The U.S. Department of Energy has estimated that over 50 GW of offshore wind power will be required for the United States to generate 20% of its electricity from wind. Developers are actively planning offshore wind farms along the U.S. Atlantic and Gulf coasts and several leases have been signed for offshore sites. These planned projects are in areas that are sometimes struck by hurricanes. We present a method to estimate the catastrophe risk to offshore wind power using simulated hurricanes. Using this method, we estimate the fraction of offshore wind power simultaneously offline and the cumulative damage in a region. In Texas, the most vulnerable region we studied, 10% of offshore wind power could be offline simultaneously because of hurricane damage with a 100-year return period and 6% could be destroyed in any 10-year period. We also estimate the risks to single wind farms in four representative locations; we find the risks are significant but lower than those estimated in previously published results. Much of the hurricane risk to offshore wind turbines can be mitigated by designing turbines for higher maximum wind speeds, ensuring that turbine nacelles can turn quickly to track the wind direction even when grid power is lost, and building in areas with lower risk.

  20. Hurricane Katrina winds damaged longleaf pine less than loblolly pine

    Science.gov (United States)

    Kurt H. Johnsen; John R. Butnor; John S. Kush; Ronald C. Schmidtling; C. Dana. Nelson

    2009-01-01

    Some evidence suggests that longleaf pine might be more tolerant of high winds than either slash pine (Pinus elliotii Englem.) or loblolly pine (Pinus taeda L.). We studied wind damage to these three pine species in a common garden experiment in southeast Mississippi following Hurricane Katrina,...

  1. Divine Wind - The History and Science of Hurricanes

    Science.gov (United States)

    Emanuel, Kerry

    2005-09-01

    Imagine standing at the center of a Roman coliseum that is 20 miles across, with walls that soar 10 miles into the sky, towering walls with cascades of ice crystals falling along its brilliantly white surface. That's what it's like to stand in the eye of a hurricane. In Divine Wind , Kerry Emanuel, one of the world's leading authorities on hurricanes, gives us an engaging account of these awe-inspiring meteorological events, revealing how hurricanes and typhoons have literally altered human history, thwarting military incursions and changing the course of explorations. Offering an account of the physics of the tropical atmosphere, the author explains how such benign climates give rise to the most powerful storms in the world and tells what modern science has learned about them. Interwoven with this scientific account are descriptions of some of the most important hurricanes in history and relevant works of art and literature. For instance, he describes the 17th-century hurricane that likely inspired Shakespeare's The Tempest and that led to the British colonization of Bermuda. We also read about the Galveston Hurricane of 1900, by far the worst natural calamity in U.S. history, with a death toll between 8,000 and 12,000 that exceeded the San Francisco earthquake, the Johnstown Flood, and the Okeechobee Hurricane combined. Boasting more than one hundred color illustrations, from ultra-modern Doppler imagery to classic paintings by Winslow Homer, Divine Wind captures the profound effects that hurricanes have had on humanity. Its fascinating blend of history, science, and art will appeal to weather junkies, science buffs, and everyone who read Isaac's Storm .

  2. Gone with the Wind? Integrity and Hurricane Katrina

    Science.gov (United States)

    Lucas, Frances; Katz, Brit

    2011-01-01

    Hurricane Katrina slammed into 80 miles of Mississippi shoreline on August 29, 2005. It was the nation's worst natural disaster, a perfect storm. One hundred sixty miles-per-hour winds sent 55-foot-tall waves and a 30-foot wall of water across the shore and miles inland. It displaced 400,000 residents along the coast of the Mississippi, and…

  3. Quantifying the hurricane risk to offshore wind turbines.

    Science.gov (United States)

    Rose, Stephen; Jaramillo, Paulina; Small, Mitchell J; Grossmann, Iris; Apt, Jay

    2012-02-28

    The U.S. Department of Energy has estimated that if the United States is to generate 20% of its electricity from wind, over 50 GW will be required from shallow offshore turbines. Hurricanes are a potential risk to these turbines. Turbine tower buckling has been observed in typhoons, but no offshore wind turbines have yet been built in the United States. We present a probabilistic model to estimate the number of turbines that would be destroyed by hurricanes in an offshore wind farm. We apply this model to estimate the risk to offshore wind farms in four representative locations in the Atlantic and Gulf Coastal waters of the United States. In the most vulnerable areas now being actively considered by developers, nearly half the turbines in a farm are likely to be destroyed in a 20-y period. Reasonable mitigation measures--increasing the design reference wind load, ensuring that the nacelle can be turned into rapidly changing winds, and building most wind plants in the areas with lower risk--can greatly enhance the probability that offshore wind can help to meet the United States' electricity needs.

  4. Estimated Drag Coefficients and Wind Structure of Hurricane Frances

    Science.gov (United States)

    Zedler, S. E.; Niiler, P. P.; Stammer, D.; Terrill, E.

    2006-12-01

    As part of the Coupled Boundary Layers Air Sea Transfer (CBLAST) experiment, an array of drifters and floats was deployed from an aircraft just ahead of Hurricane Frances during it's passage to the northwest side of the Caribbean Island chain in August, 2004. The ocean and surface air conditions prior to, during, and after Hurricane Frances were documented by multiple sensors. Two independent estimates of the surface wind field suggest different storm structures. NOAA H*WINDS, an objectively analyzed product using a combination of data collected at the reconnaissance flight level, GPS profilers (dropwindsondes), satellites, and other data, suggest a 40km radius of maximum wind. A product based on the radial momentum equation balance using \\ital{in-situ} surface pressure data and wind direction measurements from the CBLAST drifter array suggests that the radius of maximum winds was 15km. We used a regional version of the MITGCM model with closed boundaries and realistic temperature and salinity fields which was forced with these wind field products to determine which wind field leads to circulation and SST structures that are most consistent with observed sea surface temperature fields and float profile data. Best estimates of the surface wind structure are then used to estimate the appropriate drag coefficient corresponding to the maximum velocity. Our results are compared with those obtained previously.

  5. Predicting hurricane wind damage by claim payout based on Hurricane Ike in Texas

    Directory of Open Access Journals (Sweden)

    Ji-Myong Kim

    2016-09-01

    Full Text Available The increasing occurrence of natural disasters and their related damage have led to a growing demand for models that predict financial loss. Although considerable research on the financial losses related to natural disasters has found significant predictors, there has been a lack of comprehensive study that addresses the relationship among vulnerabilities, natural disasters, and the economic losses of individual buildings. This study identifies the vulnerability indicators for hurricanes to establish a metric to predict the related financial loss. We classify hurricane-prone areas by highlighting the spatial distribution of losses and vulnerabilities. This study used a Geographical Information System (GIS to combine and produce spatial data and a multiple regression method to establish a wind damage prediction model. As the dependent variable, we used the value of the Texas Windstorm Insurance Association (TWIA claim payout divided by the appraised values of the buildings to predict real economic loss. As independent variables, we selected a hurricane indicator and built environment vulnerability indicators. The model we developed can be used by government agencies and insurance companies to predict hurricane wind damage.

  6. Simulating Turbulent Wind Fields for Offshore Turbines in Hurricane-Prone Regions (Poster)

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Y.; Damiani, R.; Musial, W.

    2014-04-01

    Extreme wind load cases are one of the most important external conditions in the design of offshore wind turbines in hurricane prone regions. Furthermore, in these areas, the increase in load with storm return-period is higher than in extra-tropical regions. However, current standards have limited information on the appropriate models to simulate wind loads from hurricanes. This study investigates turbulent wind models for load analysis of offshore wind turbines subjected to hurricane conditions. Suggested extreme wind models in IEC 61400-3 and API/ABS (a widely-used standard in oil and gas industry) are investigated. The present study further examines the wind turbine response subjected to Hurricane wind loads. Three-dimensional wind simulator, TurbSim, is modified to include the API wind model. Wind fields simulated using IEC and API wind models are used for an offshore wind turbine model established in FAST to calculate turbine loads and response.

  7. On the relationship between hurricane cost and the integrated wind profile

    Science.gov (United States)

    Wang, S.; Toumi, R.

    2016-11-01

    It is challenging to identify metrics that best capture hurricane destructive potential and costs. Although it has been found that the sea surface temperature and vertical wind shear can both make considerable changes to the hurricane destructive potential metrics, it is still unknown which plays a more important role. Here we present a new method to reconstruct the historical wind structure of hurricanes that allows us, for the first time, to calculate the correlation of damage with integrated power dissipation and integrated kinetic energy of all hurricanes at landfall since 1988. We find that those metrics, which include the horizontal wind structure, rather than just maximum intensity, are much better correlated with the hurricane cost. The vertical wind shear over the main development region of hurricanes plays a more dominant role than the sea surface temperature in controlling these metrics and therefore also ultimately the cost of hurricanes.

  8. Effect of Wind Direction on ENVISAT ASAR Wind Speed Retrieval

    DEFF Research Database (Denmark)

    Takeyama, Yuko; Ohsawa, Teruo; Kozai, Katsutoshi

    2010-01-01

    This paper presents an evaluation of effects of wind directions (NCEP, MANAL, QuickSCAT and WRF) on the sea surface wind speed retrieval from 75 ENVISAT ASAR images with four C-band Geophysical model functions, CMOD4, CMOD_IFR2, CMOD5 and CMOD5N at two target areas, Hiratsuka and Shirahama...

  9. A high wind geophysical model fuction for QuikSCAT wind retrievals and application to Typhoon IOKE

    Institute of Scientific and Technical Information of China (English)

    ZOU Juhong; ZENG Tao; CUI Songxue

    2015-01-01

    The geophysical model function (GMF) describes the relationship between a backscattering and a sea surface wind, and enables a wind vector retrieval from backscattering measurements. It is clear that the GMF plays an important role in an ocean wind vector retrieval. The performance of the existing Ku-band model function QSCAT-1 is considered to be effective at low and moderate wind speed ranges. However, in the conditions of higher wind speeds, the existing algorithms diverge alarmingly. owing to the lack ofin situ data required for developing the GMF for the high wind conditions, the QSCAT-1 appears to overestimate thes0, which results in underestimating the wind speeds. Several match-up QuikSCAT and special sensor microwave/imager (SSM/I) wind speed measurements of the typhoons occurring in the west Pacific Ocean are analyzed. The results show that the SSM/I wind exhibits better agreement with the “best track” analysis wind speed than the QuikSCAT wind retrieved using QSCAT-1. On the basis of this evaluation, a correction of the QSCAT-1 model function for wind speed above 16 m/s is proposed, which uses the collocated SSM/I and QuikSCAT measurements as a training set, and a neural network approach as a multiple nonlinear regression technologytechnology.In order to validate the revised GMF for high winds, the modified GMF was applied to the QuikSCAT observations of Hurricane IOKE. The wind estimated by the QuikSCAT for Typhoon IOKE in 2006 was improved with the maximum wind speed reaching 55 m/s. An error analysis was performed using the wind fields from the Holland model as the surface truth. The results show an improved agreement with the Holland model wind when compared with the wind estimated using the QSCAT-1. However, large bias still existed, indicating that the effects of rain must be considered for further improvement.

  10. The Coplane Analysis Technique for Three-Dimensional Wind Retrieval Using the HIWRAP Airborne Doppler Radar

    Science.gov (United States)

    Didlake, Anthony C., Jr.; Heymsfield, Gerald M.; Tian, Lin; Guimond, Stephen R.

    2015-01-01

    The coplane analysis technique for mapping the three-dimensional wind field of precipitating systems is applied to the NASA High Altitude Wind and Rain Airborne Profiler (HIWRAP). HIWRAP is a dual-frequency Doppler radar system with two downward pointing and conically scanning beams. The coplane technique interpolates radar measurements to a natural coordinate frame, directly solves for two wind components, and integrates the mass continuity equation to retrieve the unobserved third wind component. This technique is tested using a model simulation of a hurricane and compared to a global optimization retrieval. The coplane method produced lower errors for the cross-track and vertical wind components, while the global optimization method produced lower errors for the along-track wind component. Cross-track and vertical wind errors were dependent upon the accuracy of the estimated boundary condition winds near the surface and at nadir, which were derived by making certain assumptions about the vertical velocity field. The coplane technique was then applied successfully to HIWRAP observations of Hurricane Ingrid (2013). Unlike the global optimization method, the coplane analysis allows for a transparent connection between the radar observations and specific analysis results. With this ability, small-scale features can be analyzed more adequately and erroneous radar measurements can be identified more easily.

  11. Applications of SMAP data to retrieval of ocean surface wind and salinity

    Science.gov (United States)

    Yueh, Simon; Fore, Alexander; Tang, Wenqing; Hayashi, Akiko; Stiles, Bryan; Zhang, Fuqing; Weng, Yonghui; Real, Nicolas

    2016-10-01

    We have examined the L-band radiometer and radar data from NASA's Soil Moisture Active Passive (SMAP) mission for ocean research and applications. We find that the SMAP data are in excellent agreement with the geophysical model function (GMF) derived from the Aquarius data up to a wind speed of 20 ms-1. For severe wind conditions, the higher resolution data from SMAP allowed us to assess the sensitivity of L-band radiometer signals to hurricane force winds. We applied the L-band GMF to the retrieval of ocean surface wind and SSS from the SMAP data. Comparison with the European Center for Medium-Range Weather Forecasting, WindSat and RapidSCAT wind speeds suggests that SMAP's radiometer wind speed reaches an excellent accuracy of about 1.1-1.7 ms-1 below a wind speed of 20 ms-1. We have also found that the maximum wind speed derived from the SMAP radiometer data can reach 140 knots for severe storms and are generally in good agreement with the hurricane track analysis and operational aircraft Stepped Frequency Microwave Radiometer wind speeds. The spatial patterns of the SMAP SSS agree well with climatological distributions, but exhibit several unique spatial and temporal features.

  12. Improvement of risk estimate on wind turbine tower buckled by hurricane

    CERN Document Server

    Li, Jingwei

    2013-01-01

    Wind is one of the important reasonable resources. However, wind turbine towers are sure to be threatened by hurricanes. In this paper, method to estimate the number of wind turbine towers that would be buckled by hurricanes is discussed. Monte Carlo simulations show that our method is much better than the previous one. Since in our method, the probability density function of the buckling probability of a single turbine tower in a single hurricane is obtained accurately but not from one approximated expression. The result in this paper may be useful to the design and maintenance of wind farms.

  13. Gusts and shear within hurricane eyewalls can exceed offshore wind turbine design standards

    Science.gov (United States)

    Worsnop, Rochelle P.; Lundquist, Julie K.; Bryan, George H.; Damiani, Rick; Musial, Walt

    2017-06-01

    Offshore wind energy development is underway in the U.S., with proposed sites located in hurricane-prone regions. Turbine design criteria outlined by the International Electrotechnical Commission do not encompass the extreme wind speeds and directional shifts of hurricanes stronger than category 2. We examine a hurricane's turbulent eyewall using large-eddy simulations with Cloud Model 1. Gusts and mean wind speeds near the eyewall of a category 5 hurricane exceed the current Class I turbine design threshold of 50 m s-1 mean wind and 70 m s-1 gusts. Largest gust factors occur at the eye-eyewall interface. Further, shifts in wind direction suggest that turbines must rotate or yaw faster than current practice. Although current design standards omit mention of wind direction change across the rotor layer, large values (15-50°) suggest that veer should be considered.

  14. Baseline Design of a Hurricane-Resilient Wind Turbine (Poster)

    Energy Technology Data Exchange (ETDEWEB)

    Damiani, R.; Robertson, A.; Schreck, S.; Maples, B.; Anderson, M.; Finucane, Z.; Raina, A.

    2014-10-01

    Under U.S. Department of Energy-sponsored research FOA 415, the National Renewable Energy Laboratory led a team of research groups to produce a complete design of a large wind turbine system to be deployable in the western Gulf of Mexico region. As such, the turbine and its support structure would be subjected to hurricane-loading conditions. Among the goals of this research was the exploration of advanced and innovative configurations that would help decrease the levelized cost of energy (LCOE) of the design, and the expansion of the basic IEC design load cases (DLCs) to include hurricane environmental conditions. The wind turbine chosen was a three-bladed, downwind, direct-drive, 10-MW rated machine. The rotor blade was optimized based on an IEC load suite analysis. The drivetrain and nacelle components were scaled up from a smaller sized turbine using industry best practices. The tubular steel tower was sized using ultimate load values derived from the rotor optimization analysis. The substructure is an innovative battered and raked jacket structure. The innovative turbine has also been modeled within an aero-servo-hydro-elastic tool, and future papers will discuss results of the dynamic response analysis for select DLCs. Although multiple design iterations could not be performed because of limited resources in this study, and are left to future research, the obtained data will offer a good indication of the expected LCOE for large offshore wind turbines to be deployed in subtropical U.S. waters, and the impact design innovations can have on this value.

  15. Gusts and Shear Within Hurricane Eyewalls Can Exceed Offshore Wind-Turbine Design Standards

    CERN Document Server

    Worsnop, Rochelle P; Bryan, George H; Damiani, Rick; Musial, Walt

    2016-01-01

    Offshore wind energy development is underway in the U.S., with proposed sites located in hurricane-prone regions. Turbine design criteria outlined by the International Electrotechnical Commission do not encompass the extreme wind speeds and directional shifts of hurricanes stronger than a Category 2. We examine the most turbulent portion of a hurricane (the eyewall) using large-eddy simulations with Cloud Model 1 (CM1). Gusts and mean wind speeds near the eyewall exceed the current design threshold of 50 m s-1 mean wind and 70 m s-1 gusts for Class I turbines. Gust factors are greatest at the eye-eyewall interface. Further, shifts in wind direction at wind turbine hub height suggest turbines must rotate into the wind faster than current practice. Although current design standards omit mention of wind direction change across the rotor layer, large values (15-50 deg) suggest that veer should be considered in design standards.

  16. Improved understanding of near-ground winds in hurricanes and tornadoes

    Science.gov (United States)

    Karstens, Christopher Daniel

    Hurricanes and tornadoes contain the most destructive and life threatening winds on the planet. Combined, they are responsible for approximately $11 billion in damage in the U.S. annually. To compose a set of effective mitigation techniques, a comprehensive understanding of hurricane and tornado winds is needed. However, our understanding of these winds in the lowest 30 meters AGL, particularly their interaction with complex terrain, is lacking. This thesis includes two studies that address this issue. In the first study, a representative wind profile extracted from WRF simulations of hurricanes is used to initialize CFD modeled flow interaction with built structures using Fluent. The magnitude of structurally-induced modifications to the wind profile is presented. In the second study, recent tornado pressure and wind measurements are compared to laboratory and numerical simulations of tornado-like vortices. In addition, a comparative range of minimum pressures from a wide variety of tornadoes with different size and intensities is presented.

  17. Dependency of U.S. Hurricane Economic Loss on Maximum Wind Speed and Storm Size

    CERN Document Server

    Zhai, Alice R

    2014-01-01

    Many empirical hurricane economic loss models consider only wind speed and neglect storm size. These models may be inadequate in accurately predicting the losses of super-sized storms, such as Hurricane Sandy in 2012. In this study, we examined the dependencies of normalized U.S. hurricane loss on both wind speed and storm size for 73 tropical cyclones that made landfall in the U.S. from 1988 to 2012. A multi-variate least squares regression is used to construct a hurricane loss model using both wind speed and size as predictors. Using maximum wind speed and size together captures more variance of losses than using wind speed or size alone. It is found that normalized hurricane loss (L) approximately follows a power law relation with maximum wind speed (Vmax) and size (R). Assuming L=10^c Vmax^a R^b, c being a scaling factor, the coefficients, a and b, generally range between 4-12 and 2-4, respectively. Both a and b tend to increase with stronger wind speed. For large losses, a weighted regression model, with...

  18. Experimental modeling of the effect of hurricane wind forces on driving behavior and vehicle performance.

    Science.gov (United States)

    Rodriguez, Jose M; Codjoe, Julius; Osman, Osama; Ishak, Sherif; Wolshon, Brian

    2015-01-01

    While traffic planning is important for developing a hurricane evacuation plan, vehicle performance on the roads during extreme weather conditions is critical to the success of the planning process. This novel study investigates the effect of gusty hurricane wind forces on the driving behavior and vehicle performance. The study explores how the parameters of a driving simulator could be modified to reproduce wind loadings experienced by three vehicle types (passenger car, ambulance, and bus) during gusty hurricane winds, through manipulation of appropriate software. Thirty participants were then tested on the modified driving simulator under five wind conditions (ranging from normal to hurricane category 4). The driving performance measures used were heading error and lateral displacement. The results showed that higher wind forces resulted in more varied and greater heading error and lateral displacement. The ambulance had the greatest heading errors and lateral displacements, which were attributed to its large lateral surface area and light weight. Two mathematical models were developed to estimate the heading error and lateral displacements for each of the vehicle types for a given change in lateral wind force. Through a questionnaire, participants felt the different characteristics while driving each vehicle type. The findings of this study demonstrate the valuable use of a driving simulator to model the behavior of different vehicle types and to develop mathematical models to estimate and quantify driving behavior and vehicle performance under hurricane wind conditions.

  19. Hurricane Imaging Radiometer

    Science.gov (United States)

    Cecil, Daniel J.; Biswas, Sayak K.; James, Mark W.; Roberts, J. Brent; Jones, W. Linwood; Johnson, James; Farrar, Spencer; Sahawneh, Saleem; Ruf, Christopher S.; Morris, Mary; hide

    2014-01-01

    The Hurricane Imaging Radiometer (HIRAD) is a synthetic thinned array passive microwave radiometer designed to allow retrieval of surface wind speed in hurricanes, up through category five intensity. The retrieval technology follows the Stepped Frequency Microwave Radiometer (SFMR), which measures surface wind speed in hurricanes along a narrow strip beneath the aircraft. HIRAD maps wind speeds in a swath below the aircraft, about 50-60 km wide when flown in the lower stratosphere. HIRAD has flown in the NASA Genesis and Rapid Intensification Processes (GRIP) experiment in 2010 on a WB-57 aircraft, and on a Global Hawk unmanned aircraft system (UAS) in 2012 and 2013 as part of NASA's Hurricane and Severe Storms Sentinel (HS3) program. The GRIP program included flights over Hurricanes Earl and Karl (2010). The 2012 HS3 deployment did not include any hurricane flights for the UAS carrying HIRAD. The 2013 HS3 flights included one flight over the predecessor to TS Gabrielle, and one flight over Hurricane Ingrid. This presentation will describe the HIRAD instrument, its results from the 2010 and 2013 flights, and potential future developments.

  20. 3-D Hurricane Wind Retrieval Algorithm with Airborne Doppler Radar Measurements%基于机载多普勒雷达数据的飓风内部三维风场反演算法

    Institute of Scientific and Technical Information of China (English)

    柯樱海; 张雪虎; 陈秀万; 杨吉龙; David J McLaughlin; Paul Chang; Peter Black; Frank Marks

    2005-01-01

    利用2002年NOAA海洋飓风实验中三维风雨微波成像仪(IWRAP,UMass Imaging Wind and Rain Airborne Profiler)数据,提出了两种自适应卡尔曼滤波算法进行飓风三维风矢量的反演.为验证不同自适应滤波算法的准确性,通过对实际风场以及相应的机载雷达观测数据进行仿真,得到一种最优自适应滤波;文中对滤波结果误差进行了初步分析,探讨了误差来源.根据仿真结果,利用最优自适应滤波对2002年10月2日飓风莉莉多普勒雷达测量数据进行处理,滤波得到的三维风场与本次实验中GPS下投式探空仪的三维风场同步测量数据,多波段微波辐射计的海面风场测量数据,以及飞机高度风场数据进行了比较.

  1. Wind vector retrieval using dual polarization imagery of ASAR

    Institute of Scientific and Technical Information of China (English)

    SONG Guiting; HOU Yijun; QI Peng

    2006-01-01

    A new algorithm for retrieving wind vector using dual polarization imagery of advanced synthetic aperture radar (ASAR) is developed and tested. Based on the combination of co-polarization and cross-polarization, this new algorithm effectively eliminates the 180° ambiguity which occurs when using single imagery of the ASAR to retrieve wind vector. This algorithm also solves the problem that the retrieval results will break down on very small spatial scales. The results retrieved from dual polarization imagery of ASAR show that the wind speed and direction are in agreement with the data from Quikscat and buoy measurements. The root mean square errors of wind direction and speed between the retrieved results and data from Quikscat are 2.21° and 0.53 m/s, respectively.Comparisons between the new method and the traditional method show that the new methods fit the buoy data and Quikscat data a little better than the traditional method in this image.

  2. Comparison of SAR Wind Speed Retrieval Algorithms for Evaluating Offshore Wind Energy Resources

    DEFF Research Database (Denmark)

    Kozai, K.; Ohsawa, T.; Takeyama, Y.

    2010-01-01

    Envisat/ASAR-derived offshore wind speeds and energy densities based on 4 different SAR wind speed retrieval algorithms (CMOD4, CMOD-IFR2, CMOD5, CMOD5.N) are compared with observed wind speeds and energy densities for evaluating offshore wind energy resources. CMOD4 ignores effects of atmospheric...

  3. Observations of C-Band Brightness Temperature and Ocean Surface Wind Speed and Rain Rate in Hurricanes Earl And Karl (2010)

    Science.gov (United States)

    Miller, Timothy; James, Mark; Roberts, Brent J.; Biswax, Sayak; Uhlhorn, Eric; Black, Peter; Linwood Jones, W.; Johnson, Jimmy; Farrar, Spencer; Sahawneh, Saleem

    2012-01-01

    Ocean surface emission is affected by: a) Sea surface temperature. b) Wind speed (foam fraction). c) Salinity After production of calibrated Tb fields, geophysical fields wind speed and rain rate (or column) are retrieved. HIRAD utilizes NASA Instrument Incubator Technology: a) Provides unique observations of sea surface wind, temp and rain b) Advances understanding & prediction of hurricane intensity c) Expands Stepped Frequency Microwave Radiometer capabilities d) Uses synthetic thinned array and RFI mitigation technology of Lightweight Rain Radiometer (NASA Instrument Incubator) Passive Microwave C-Band Radiometer with Freq: 4, 5, 6 & 6.6 GHz: a) Version 1: H-pol for ocean wind speed, b) Version 2: dual ]pol for ocean wind vectors. Performance Characteristics: a) Earth Incidence angle: 0deg - 60deg, b) Spatial Resolution: 2-5 km, c) Swath: approx.70 km for 20 km altitude. Observational Goals: WS 10 - >85 m/s RR 5 - > 100 mm/hr.

  4. PTC and Partner Products in the Creation of a Hurricane Wind Sensor

    Science.gov (United States)

    Randazzo, John; Voska, N. (Technical Monitor)

    2002-01-01

    This viewgraph presentation provides information on the development of a wind sensor for use during hurricanes. The objectives of this presentation are: (1) Educate the user unfamiliar with the modules as to what is available/lacking; (2) Share where some changes could be made; (3) Look at alternative approaches made possible by new releases/modules; (4) Use feedback to improve processes/approaches. The current pad wind sensors are cup-and-vane type anemometers.

  5. Coastal wind field retrieval from polarimetric synthetic aperture radar

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yi; JIANG Xingwei; SONG Qingtao; LIN Mingsen; XIE Xuetong

    2014-01-01

    Coastal winds are strongly influenced by topology and discontinuity between land and sea surfaces. Wind assessment from remote sensing in such a complex area remains a challenge. Space-borne scatterometer does not provide any information about the coastal wind field, as the coarse spatial resolution hampers the radar backscattering. Synthetic aperture radar (SAR) with a high spatial resolution and all-weather observa-tion abilities has become one of the most important tools for ocean wind retrieval, especially in the coastal area. Conventional methods of wind field retrieval from SAR, however, require wind direction as initial infor-mation, such as the wind direction from numerical weather prediction models (NWP), which may not match the time of SAR image acquiring. Fortunately, the polarimetric observations of SAR enable independent wind retrieval from SAR images alone. In order to accurately measure coastal wind fields, this paper propos-es a new method of using co-polarization backscattering coefficients from polarimetric SAR observations up to polarimetric correlation backscattering coefficients, which are acquired from the conjugate product of co-polarization backscatter and cross-polarization backscatter. Co-polarization backscattering coefficients and polarimetric correlation backscattering coefficients are obtained form Radarsat-2 single-look complex (SLC) data.The maximum likelihood estimation is used to gain the initial results followed by the coarse spa-tial filtering and fine spatial filtering. Wind direction accuracy of the final inversion results is 10.67 with a wind speed accuracy of 0.32 m/s. Unlike previous methods, the methods described in this article utilize the SAR data itself to obtain the wind vectors and do not need external wind directional information. High spatial resolution and high accuracy are the most important features of the method described herein since the use of full polarimetric observations contains more information about the

  6. Effectiveness of WRF wind direction for retrieving coastal sea surface wind from synthetic aperture radar

    DEFF Research Database (Denmark)

    Takeyama, Yuko; Ohsawa, Teruo; Kozai, Katsutoshi;

    2013-01-01

    Wind direction is required as input to the geophysical model function (GMF) for the retrieval of sea surface wind speed from a synthetic aperture radar (SAR) images. The present study verifies the effectiveness of using the wind direction obtained from the weather research and forecasting model...

  7. Influence of hurricane wind field in the structure of directional wave spectra

    Science.gov (United States)

    Esquivel-Trava, Bernardo; Ocampo-Torres, Francisco J.; Osuna, Pedro

    2015-04-01

    Extensive field measurements of wind waves in deep waters in the Gulf of Mexico and Caribbean Sea, have been analyzed to describe the spatial structure of directional wave spectra during hurricane conditions. Following Esquivel-Trava et al. (2015) this analysis was made for minor hurricanes (categories 1 and 2) and major hurricanes (categories 3, 4 and 5). In both cases the directionality of the energy wave spectrum is similar in all quadrants. Some differences are observed however, and they are associated with the presence and the shape of swell energy in each quadrant. Three numerical experiments using the spectral wave prediction model SWAN were carried out to gain insight into the mechanism that controls the directional and frequency distributions of hurricane wave energy. The aim of the experiments is to evaluate the effect of the translation speed of the hurricane and the presence of concentric eye walls, on both the wave growth process and the shape of the directional wave spectrum. The HRD wind field of Hurricane Dean on August 20 at 7:30 was propagated at two different velocities (5 and 10 m/s). An idealized concentric eye wall (a Gaussian function that evolve in time along a path in the form of an Archimedean spiral) was imposed to the wind field. The white-capping formulation of Westhuysen et al. (2007) was selected. The wave model represents fairly well the directionality of the energy and the shape of the directional spectra in the hurricane domain. The model results indicate that the forward movement of the storm influences the development of the waves, consistent with field observations. This work has been supported by CONACYT scholarship 164510 and projects RugDisMar (155793), CB-2011-01-168173 and the Department of Physical Oceanography of CICESE. References Esquivel-Trava, B., Ocampo-Torres, F. J., & Osuna, P. (2015). Spatial structure of directional wave spectra in hurricanes. Ocean Dynam., 65(1), 65-76. doi:10.1007/s10236-014-0791-9 Van der

  8. Empirical wind retrieval model based on SAR spectrum measurements

    Science.gov (United States)

    Panfilova, Maria; Karaev, Vladimir; Balandina, Galina; Kanevsky, Mikhail; Portabella, Marcos; Stoffelen, Ad

    The present paper considers polarimetric SAR wind vector applications. Remote-sensing measurements of the near-surface wind over the ocean are of great importance for the understanding of atmosphere-ocean interaction. In recent years investigations for wind vector retrieval using Synthetic Aperture Radar (SAR) data have been performed. In contrast with scatterometers, a SAR has a finer spatial resolution that makes it a more suitable microwave instrument to explore wind conditions in the marginal ice zones, coastal regions and lakes. The wind speed retrieval procedure from scatterometer data matches the measured radar backscattering signal with the geophysical model function (GMF). The GMF determines the radar cross section dependence on the wind speed and direction with respect to the azimuthal angle of the radar beam. Scatterometers provide information on wind speed and direction simultaneously due to the fact that each wind vector cell (WVC) is observed at several azimuth angles. However, SAR is not designed to be used as a high resolution scatterometer. In this case, each WVC is observed at only one single azimuth angle. That is why for wind vector determination additional information such as wind streak orientation over the sea surface is required. It is shown that the wind vector can be obtained using polarimetric SAR without additional information. The main idea is to analyze the spectrum of a homogeneous SAR image area instead of the backscattering normalized radar cross section. Preliminary numerical simulations revealed that SAR image spectral maxima positions depend on the wind vector. Thus the following method for wind speed retrieval is proposed. In the first stage of the algorithm, the SAR spectrum maxima are determined. This procedure is carried out to estimate the wind speed and direction with ambiguities separated by 180 degrees due to the SAR spectrum symmetry. The second stage of the algorithm allows us to select the correct wind direction

  9. Horizontal wind velocity retrieval using a Levenberg-Marquardt algorithm for an airborne wind lidar

    Science.gov (United States)

    Zhu, Jinshan; Li, Zhigang; Liu, Zhishen

    2016-04-01

    We established a model for an airborne wind lidar. Numerical optimization algorithms should be used to solve this nonlinear model. We designed a Levenberg-Marquardt (L-M) algorithm and tested it with the modeled data. The retrieved velocity and the true velocity agree very well, and the adjusted R2 is 0.99947. We have carried out an airborne coherent wind lidar experiment in January 2015, and we used the model and the L-M algorithm to process the wind lidar experiment data, and compared the retrieved results with the radiosonde wind profile. The consistency is very good, especially at an altitude above 1.8 km. We may speculate that when the atmosphere flows are not so dramatic, the lidar and the radiosonde measurements are strictly synchronous, it is possible to retrieve horizontal wind speeds and directions consistently with the radiosonde using our wind lidar model and the L-M algorithm.

  10. Surface Wind Vector and Rain Rate Observation Capability of Future Hurricane Imaging Radiometer (HIRAD)

    Science.gov (United States)

    Miller, Timothy; Atlas, Robert; Bailey, M. C.; Black, Peter; El-Nimri, Salem; Hood, Robbie; James, Mark; Johnson, James; Jones, Linwood; Ruf, Christopher; Uhlhorn, Eric

    2009-01-01

    The Hurricane Imaging Radiometer (HIRAD) is the next-generation Stepped Frequency Microwave Radiometer (SFMR), and it will offer the capability of simultaneous wide-swath observations of both extreme ocean surface wind vector and strong precipitation from either aircraft (including UAS) or satellite platforms. HIRAD will be a compact, lightweight, low-power instrument with no moving parts that will produce valid wind observations under hurricane conditions when existing microwave sensors (radiometers or scatterometers) are hindered by precipitation. The SFMR i s a proven aircraft remote sensing system for simultaneously observing extreme ocean surface wind speeds and rain rates, including those of major hurricane intensity. The proposed HIRAD instrument advances beyond the current nadir viewing SFMR to an equivalent wide-swath SFMR imager using passive microwave synthetic thinned aperture radiometer technology. The first version of the instrument will be a single polarization system for wind speed and rain rate, with a dual-polarization system to follow for wind vector capability. This sensor will operate over 4-7 GHz (C-band frequencies) where the required tropical cyclone remote sensing physics has been validated by both SFMR and WindSat radiometers. HIRAD incorporates a unique, technologically advanced array antenna and several other technologies successfully demonstrated by NASA s Instrument Incubator Program. A brassboard (laboratory) version of the instrument has been completed and successfully tested in a test chamber. Development of the aircraft instrument is underway, with flight testing planned for the fall of 2009. Preliminary Observing System Simulation Experiments (OSSEs) show that HIRAD will have a significant positive impact on surface wind analyses as either a new aircraft or satellite sensor. New off-nadir data collected in 2008 by SFMR that affirms the ability of this measurement technique to obtain wind speed data at non-zero incidence angle will

  11. Importance of air-sea interaction on wind waves, storm surge and hurricane simulations

    Science.gov (United States)

    Chen, Yingjian; Yu, Xiping

    2017-04-01

    It was reported from field observations that wind stress coefficient levels off and even decreases when the wind speed exceeds 30-40 m/s. We propose a wave boundary layer model (WBLM) based on the momentum and energy conservation equations. Taking into account the physical details of the air-sea interaction process as well as the energy dissipation due to the presence of sea spray, this model successfully predicts the decreasing tendency of wind stress coefficient. Then WBLM is embedded in the current-wave coupled model FVCOM-SWAVE to simulate surface waves and storm surge under the forcing of hurricane Katrina. Numerical results based on WBLM agree well with the observed data of NDBC buoys and tide gauges. Sensitivity analysis of different wind stress evaluation methods also shows that large anomalies of significant wave height and surge elevation are captured along the passage of hurricane core. The differences of the local wave height are up to 13 m, which is in accordance with the general knowledge that the ocean dynamic processes under storm conditions are very sensitive to the amount of momentum exchange at the air-sea interface. In the final part of the research, the reduced wind stress coefficient is tested in the numerical forecast of hurricane Katrina. A parabolic formula fitted to WBLM is employed in the atmosphere-ocean coupled model COAWST. Considering the joint effects of ocean cooling and reduced wind drag, the intensity metrics - the minimum sea level pressure and the maximum 10 m wind speed - are in good inconsistency with the best track result. Those methods, which predict the wind stress coefficient that increase or saturate in extreme wind condition, underestimate the hurricane intensity. As a whole, we unify the evaluation methods of wind stress in different numerical models and yield reasonable results. Although it is too early to conclude that WBLM is totally applicable or the drag coefficient does decrease for high wind speed, our current

  12. The Crucial Records Number to Retrieve Offshore Directional Wind Distribution

    Science.gov (United States)

    Zhu, X.; Li, Z.; Yang, X.

    2017-02-01

    The wind energy production estimates are very important to a wind power project. And, the remote sensing technique has been widely used to obtain the offshore wind speed and direction which could be used to calculate the wind energy of potential wind farm. However, the directional wind energy distributions are rarely studied, which also play important roles in analysis of wind farms’ potential power. In this article, the minimum number of records to obtain offshore directional wind distribution is stated by simulation experiment on In-situ dataset. The NDBC buoy dataset is randomly and multiply sampled to build new dataset under different numbers of observation records, which vary from 21 to 800. The resample under the same number of observation is repeated for 100 times to build dataset group. The directional wind distribution of new dataset is compared with the one of original buoy dataset, and errors made by dataset with fewer records are calculated. Besides, the 10th largest error in the sampled dataset group, which have the same number of observation records, is regarded as the error bound for those dataset. The change rule of the error bound is shown by fitted curves. Based on the fitted curves, minimum number of records is calculated. By this simulation experiment, the minimum number of records to represent wind direction frequency is 350, and 800 for annual direction distributions of wind energy density. To reduce the number of records needed in retrieval, some methods are discussed and tested.

  13. Hurricanes

    Science.gov (United States)

    ... spawn tornadoes and lead to flooding. The high winds and heavy rains can destroy buildings, roads and bridges, and knock down power lines and trees. In coastal areas, very high tides called storm ...

  14. Investigation and classification of spume droplets production mechanisms at hurricane winds

    Science.gov (United States)

    Troitskaya, Yuliya; Kandaurov, Alexander; Ermakova, Olga; Kozlov, Dmitry; Sergeev, Daniil; Zilitinkevich, Sergey

    2016-04-01

    Sea sprays are typical element of the marine atmospheric boundary layer of important environmental effect. There are still significant uncertainties in estimations of these effects due to insufficient knowledge on the sea spray generation function. The reason for that are difficulties of direct measurements and insufficient knowledge about the mechanisms of the spume droplet's formation. This study is concerned with the laboratory experiments for identification of mechanisms due to which a strong wind tears off water from the crest of the waves made at the high-speed wind-wave flume of IAP RAS. In order to obtain statistical data for the events on the surface, leading to the spray generation a high-speed video-filming was made using a horizontal and vertical shadow methods at rates of up to 10,000 fps in a wide range of wind speeds (20 - 35 m/s). Classification of phenomena responsible for generation of spume droplets was made. It was observed for the friction velocities from 0.8 to 1.5 m/s that the generation of the spume droplets is caused by 3 types of local phenomena: breaking of "projections" see e.g.[1], bursting of submerged bubbles [2,3] and bag breakup - it begins with increase of small-scale elevation of the surface, transforming to small "sails" then inflated to a water film bordered by a thicker rim and at last blows up, so the droplets are produced from rupture of the water film and fragmentation of the rim (the first report on the observation of a new mechanism of spume droplets', similar to bag-breakup regime was made in [4]). Statistical analysis of number of these phenomena at different winds showed that the "bag-breakup" is the major mechanism of spume droplets generation at strong and hurricane winds. Statistical distributions of observed "bags" geometrical parameters at different airflow velocities were retrieved from video-filming using specially developed software which allowed semi-automatic registering of image features. Acknowledgements

  15. Wind retrieval from synthetic aperture radar - an overview

    DEFF Research Database (Denmark)

    Dagestad, Knut-Frode; Horstmann, Jochen; Mouche, Alexis

    2013-01-01

    This paper represents a consensus on the state-of-the-art in wind retrieval using synthetic aperture radar (SAR), after the SEASAR 2012 workshop “Advances in SAR Oceanography” hosted by the European Space Agency (ESA) and the Norwegian Space Centre in Tromsø, Norway 18–22 June 2012. We document...

  16. Applicability of Synthetic Aperture Radar Wind Retrievals on Offshore Wind Resources Assessment in Hangzhou Bay, China

    DEFF Research Database (Denmark)

    Chang, Rui; Zhu, Rong; Badger, Merete

    2014-01-01

    In view of the high cost and sparse spatial resolution of offshore meteorological observations, ocean winds retrieved from satellites are valuable in offshore wind resource assessment as a supplement to in situ measurements. This study examines satellite synthetic aperture radar (SAR) images from...... ENVISAT advanced SAR (ASAR) for mapping wind resources with high spatial resolution. Around 181 collected pairs of wind data from SAR wind maps and from 13 meteorological stations in Hangzhou Bay are compared. The statistical results comparing in situ wind speed and SAR-based wind speed show a standard...... density functions are compared at one meteorological station. The SAR-based results appear not to estimate the mean wind speed, Weibull scale and shape parameters and wind power density from the full in situ data set so well due to the lower number of satellite samples. Distributions calculated from...

  17. An Improved Wind Speed Retrieval Algorithm For The CYGNSS Mission

    Science.gov (United States)

    Ruf, C. S.; Clarizia, M. P.

    2015-12-01

    The NASA spaceborne Cyclone Global Navigation Satellite System (CYGNSS) mission is a constellation of 8 microsatellites focused on tropical cyclone (TC) inner core process studies. CYGNSS will be launched in October 2016, and will use GPS-Reflectometry (GPS-R) to measure ocean surface wind speed in all precipitating conditions, and with sufficient frequency to resolve genesis and rapid intensification. Here we present a modified and improved version of the current baseline Level 2 (L2) wind speed retrieval algorithm designed for CYGNSS. An overview of the current approach is first presented, which makes use of two different observables computed from 1-second Level 1b (L1b) delay-Doppler Maps (DDMs) of radar cross section. The first observable, the Delay-Doppler Map Average (DDMA), is the averaged radar cross section over a delay-Doppler window around the DDM peak (i.e. the specular reflection point coordinate in delay and Doppler). The second, the Leading Edge Slope (LES), is the leading edge of the Integrated Delay Waveform (IDW), obtained by integrating the DDM along the Doppler dimension. The observables are calculated over a limited range of time delays and Doppler frequencies to comply with baseline spatial resolution requirements for the retrieved winds, which in the case of CYGNSS is 25 km. In the current approach, the relationship between the observable value and the surface winds is described by an empirical Geophysical Model Function (GMF) that is characterized by a very high slope in the high wind regime, for both DDMA and LES observables, causing large errors in the retrieval at high winds. A simple mathematical modification of these observables is proposed, which linearizes the relationship between ocean surface roughness and the observables. This significantly reduces the non-linearity present in the GMF that relate the observables to the wind speed, and reduces the root-mean square error between true and retrieved winds, particularly in the high wind

  18. Evaluation of the CPTEC/AGCM wind forecasts during the hurricane Catarina occurrence

    Directory of Open Access Journals (Sweden)

    A. F. Santos

    2008-05-01

    Full Text Available In March 2004 occurred the first hurricane registered at South Atlantic Ocean. The system named Catarina begun as an extratropical cyclone and remained quasi-stationary some days over the South Atlantic Ocean. The system displaced westward, acquiring characteristics of a hurricane and hit the Brazilian State of Santa Catarina (SC between the 27 and the 28 March, causing destruction and deaths. The objective of this paper is to evaluate the Center for Weather Prediction and Climate Studies, Atmospheric Global Circulation Model (CPTEC/AGCM forecast performance of some synoptic patterns associated with Catarina. The surface wind and reduced Sea Level Pressure (SLP were examined. Moreover, the implementation of 10-m wind forecast (V10m was evaluated. This variable was not available in the CPTEC/AGCM during the Catarina occurrence and in this study it was compared with the wind at first sigma-level of the AGCM. The CPTEC-Eta reanalyses were used to comparisons. According to reanalyses, more intense winds were observed in northeast, south and southwest edges of the cyclone. The system was not predicted by the CPTEC/AGCM forecasts longer than 24 h, then the analyses were carried out only for 24 h forecasts. In general, the first sigma-level wind forecasts underestimated the wind magnitude and the cyclone intensity. However, the Catarina formation and its displacement southeastward between the 20 and the 21 March were well represented by the model. The CPTEC/AGCM presents deficiencies to predict the system intensity, but in short-range forecasts it was possible to predict the system formation and its atypical trajectory. The wind results from the new implementation did not exhibit better performance compared with the wind at first sigma-level. These results will be better investigated in the future.

  19. Applicability of Synthetic Aperture Radar Wind Retrievals on Offshore Wind Resources Assessment in Hangzhou Bay, China

    Directory of Open Access Journals (Sweden)

    Rui Chang

    2014-05-01

    Full Text Available In view of the high cost and sparse spatial resolution of offshore meteorological observations, ocean winds retrieved from satellites are valuable in offshore wind resource assessment as a supplement to in situ measurements. This study examines satellite synthetic aperture radar (SAR images from ENVISAT advanced SAR (ASAR for mapping wind resources with high spatial resolution. Around 181 collected pairs of wind data from SAR wind maps and from 13 meteorological stations in Hangzhou Bay are compared. The statistical results comparing in situ wind speed and SAR-based wind speed show a standard deviation (SD of 1.99 m/s and correlation coefficient of R = 0.67. The model wind directions, which are used as input for the SAR wind speed retrieval, show a high correlation coefficient (R = 0.89 but a large standard deviation (SD = 42.3° compared to in situ observations. The Weibull probability density functions are compared at one meteorological station. The SAR-based results appear not to estimate the mean wind speed, Weibull scale and shape parameters and wind power density from the full in situ data set so well due to the lower number of satellite samples. Distributions calculated from the concurrent 81 SAR and in situ samples agree well.

  20. Impact of Spatial Resolution on Wind Field Derived Estimates of Air Pressure Depression in the Hurricane Eye

    Directory of Open Access Journals (Sweden)

    Linwood Jones

    2010-03-01

    Full Text Available Measurements of the near surface horizontal wind field in a hurricane with spatial resolution of order 1–10 km are possible using airborne microwave radiometer imagers. An assessment is made of the information content of the measured winds as a function of the spatial resolution of the imager. An existing algorithm is used which estimates the maximum surface air pressure depression in the hurricane eye from the maximum wind speed. High resolution numerical model wind fields from Hurricane Frances 2004 are convolved with various HIRAD antenna spatial filters to observe the impact of the antenna design on the central pressure depression in the eye that can be deduced from it.

  1. On the Use of Coupled Wind, Wave, and Current Fields in the Simulation of Loads on Bottom-Supported Offshore Wind Turbines during Hurricanes: March 2012 - September 2015

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eungsoo [Univ. of Texas, Austin, TX (United States); Manuel, Lance [Univ. of Texas, Austin, TX (United States); Curcic, Milan [Univ. of Miami, Coral Gables, FL (United States); Chen, Shuyi S. [Univ. of Miami, Coral Gables, FL (United States); Phillips, Caleb [National Renewable Energy Lab. (NREL), Golden, CO (United States); Veers, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-06-01

    In the United States, potential offshore wind plant sites have been identified along the Atlantic seaboard and in the Gulf of Mexico. It is imperative that we define external conditions associated with hurricanes and severe winter storms and consider load cases for which wind turbines may need to be designed. We selected two hurricanes, Ike (2008) and Sandy (2012), and investigated the effect these tropical storms would have on bottom-supported offshore wind turbines that were hypothetically in or close to their path as they made landfall. For realistic turbine loads assessment, it is important that the coupled influences of the changing wind, wave, and current fields are simulated throughout the evolution of the hurricanes. We employed a coupled model--specifically, the University of Miami Coupled Model (UMCM)--that integrates atmospheric, wave, and ocean components to produce needed wind, wave, and current data. The wind data are used to generate appropriate vertical wind profiles and full wind velocity fields including turbulence; the current field over the water column is obtained by interpolated discrete output current data; and short-crested irregular second-order waves are simulated using output directional wave spectra from the coupled model. We studied two monopile-supported offshore wind turbines sited in 20 meters of water in the Gulf of Mexico to estimate loads during Hurricane Ike, and a jacket space-frame platform-supported offshore wind turbine sited in 50 meters of water in the mid-Atlantic region to estimate loads during Hurricane Sandy. In this report we discuss in detail how the simulated hurricane wind, wave, and current output data are used in turbine loads studies. In addition, important characteristics of the external conditions are studied, including the relative importance of swell versus wind seas, aerodynamic versus hydrodynamic forces, current velocity effects, yaw control options for the turbine, hydrodynamic drag versus inertia forces

  2. Influence of hurricane wind field in the structure of directional wave spectra.

    Science.gov (United States)

    Esquivel-Trava, Bernardo; García-Nava, Hector; Osuna, Pedro; Ocampo-Torres, Francisco J.

    2017-04-01

    Three numerical experiments using the spectral wave prediction model SWAN were carried out to gain insight into the mechanism that controls the directional and frequency distributions of hurricane wave energy. One particular objective is to evaluate the effect of the translation speed of the hurricane and the presence of concentric eye walls, on both the wave growth process and the shape of the directional wave spectrum. The HRD wind field of Hurricane Dean on August 20 at 7:30 was propagated at two different velocities (5 and 10 m/s). An idealized concentric eye wall (a Gaussian function that evolve in time along a path in the form of an Archimedean spiral) was imposed to the wind field. The white-capping formulation of Westhuysen et al. (2007) was selected. The wave model represents fairly well the directionality of the energy and the shape of the directional spectra in the hurricane domain. The model results indicate that the forward movement of the storm influences the development of the waves, consistent with field observations. Additionally the same experiments were carried out using the Wave Watch III model with the source terms formulation proposed by Ardhuin et al., 2010, with the aim of making comparisons between the physical processes that represent each formulation, and the latest results will be addressed. References Ardhuin, F., Rogers, E., Babanin, A. V., Filipot, J.-F., Magne, R., Roland, A., van der Westhuysen, A., et al. (2010). Semiempirical Dissipation Source Functions for Ocean Waves. Part I: Definition, Calibration, and Validation. Journal of Physical Oceanography, 40(9), 1917-1941. doi:10.1175/2010JPO4324.1 Van der Westhuysen, A. J., Zijlema, M., & Battjes, J. A. (2007). Nonlinear saturation-based whitecapping dissipation in SWAN for deep and shallow water. Coast. Eng., 54(2), 151-170. doi:10.1016/j.coastaleng.2006.08.006

  3. Hurricane Imaging Radiometer (HIRAD) Observations of Brightness Temperatures and Ocean Surface Wind Speed and Rain Rate During NASA's GRIP and HS3 Campaigns

    Science.gov (United States)

    Miller, Timothy L.; James, M. W.; Roberts, J. B.; Jones, W. L.; Biswas, S.; Ruf, C. S.; Uhlhorn, E. W.; Atlas, R.; Black, P.; Albers, C.

    2012-01-01

    HIRAD flew on high-altitude aircraft over Earl and Karl during NASA s GRIP (Genesis and Rapid Intensification Processes) campaign in August - September of 2010, and plans to fly over Atlantic tropical cyclones in September of 2012 as part of the Hurricane and Severe Storm Sentinel (HS3) mission. HIRAD is a new C-band radiometer using a synthetic thinned array radiometer (STAR) technology to obtain spatial resolution of approximately 2 km, out to roughly 30 km each side of nadir. By obtaining measurements of emissions at 4, 5, 6, and 6.6 GHz, observations of ocean surface wind speed and rain rate can be retrieved. The physical retrieval technique has been used for many years by precursor instruments, including the Stepped Frequency Microwave Radiometer (SFMR), which has been flying on the NOAA and USAF hurricane reconnaissance aircraft for several years to obtain observations within a single footprint at nadir angle. Results from the flights during the GRIP and HS3 campaigns will be shown, including images of brightness temperatures, wind speed, and rain rate. Comparisons will be made with observations from other instruments on the campaigns, for which HIRAD observations are either directly comparable or are complementary. Features such as storm eye and eye-wall, location of storm wind and rain maxima, and indications of dynamical features such as the merging of a weaker outer wind/rain maximum with the main vortex may be seen in the data. Potential impacts on operational ocean surface wind analyses and on numerical weather forecasts will also be discussed.

  4. Wind vector retrieval algorithm from spaceborne lidar data

    Institute of Scientific and Technical Information of China (English)

    WANG Tianyu; PAN Delu; HE Xianqiang; WANG Difeng

    2014-01-01

    The principal purpose of this paper is to extract entire sea surface wind’s information from spaceborne lidar, and particularly to utilize a appropriate algorithm for removing the interference information due to white-caps and subsurface water. Wind speeds are obtained through empirical relationship with sea surface mean square slopes. Wind directions are derived from relationship between wind speeds and wind directions im-plied in CMOD5n geophysical models function (GMF). Whitecaps backscattering signals were distinguished with the help of lidar depolarization ratio measurements and rectified by whitecaps coverage equation. Subsurface water backscattering signals were corrected by means of inverse distance weighted (IDW ) from neighborhood non-singular data with optimal subsurface water backscattering calibration parameters. To verify the algorithm reliably, it selected NDBC’s TAO buoy-laying area as survey region in camparison with buoys’ wind field data and METOP satellite ASCAT of 25 km single orbit wind field data after temporal-spa-tial matching. Validation results showed that the retrieval algorithm works well in terms of root mean square error (RMSE) less than 2m/s and wind direction’s RMSE less than 21 degree.

  5. A Look Inside Hurricane Alma

    Science.gov (United States)

    2002-01-01

    Hurricane season in the eastern Pacific started off with a whimper late last month as Alma, a Category 2 hurricane, slowly made its way up the coast of Baja California, packing sustained winds of 110 miles per hour and gusts of 135 miles per hour. The above image of the hurricane was acquired on May 29, 2002, and displays the rainfall rates occurring within the storm. Click the image above to see an animated data visualization (3.8 MB) of the interior of Hurricane Alma. The images of the clouds seen at the beginning of the movie were retrieved from the National Oceanic and Atmospheric Association's (NOAA's) Geostationary Orbiting Environmental Satellite (GOES) network. As the movie continues, the clouds are peeled away to reveal an image of rainfall levels in the hurricane. The rainfall data were obtained by the Precipitation Radar aboard NASA's Tropical Rainfall Measuring Mission (TRMM) satellite. The Precipitation Radar bounces radio waves off of clouds to retrieve a reading of the number of large, rain-sized droplets within the clouds. Using these data, scientists can tell how much precipitation is occurring within and beneath a hurricane. In the movie, yellow denotes areas where 0.5 inches of rain is falling per hour, green denotes 1 inch per hour, and red denotes over 2 inches per hour. (Please note that high resolution still images of Hurricane Alma are available in the NASA Visible Earth in TIFF format.) Image and animation courtesy Lori Perkins, NASA Goddard Space Flight Center Scientific Visualization Studio

  6. Identifying Stratospheric Air Intrusions and Associated Hurricane-Force Wind Events over the North Pacific Ocean

    Science.gov (United States)

    Malloy, Kelsey; Folmer, Michael J.; Phillips, Joseph; Sienkiewicz, Joseph M.; Berndt, Emily

    2017-01-01

    Motivation: Ocean data is sparse: reliance on satellite imagery for marine forecasting; Ocean Prediction Center (OPC) –“mariner’s weather lifeline”. Responsible for: Pacific, Atlantic, Pacific Alaska surface analyses –24, 48, 96 hrs.; Wind & wave analyses –24, 48, 96 hrs.; Issue warnings, make decisions, Geostationary Operational Environmental Satellite –R Series (now GOES-16), Compared to the old GOES: 3 times spectral resolution, 4 times spatial resolution, 5 times faster coverage; Comparable to Japanese Meteorological Agency’s Himawari-8, used a lot throughout this research. Research Question: How can integrating satellite data imagery and derived products help forecasters improve prognosis of rapid cyclogenesis and hurricane-force wind events? Phase I –Identifying stratospheric air intrusions: Water Vapor –6.2, 6.9, 7.3 micron channels; Airmass RGB Product; AIRS, IASI, NUCAPS total column ozone and ozone anomaly; ASCAT (A/B) and AMSR-2 wind data.

  7. Hurricane Frances as Observed by NASA's Spaceborne Atmospheric Infrared Sounder (AIRS) and SeaWinds

    Science.gov (United States)

    2004-01-01

    This image shows Hurricane Frances as captured by instruments onboard two different satellites: the AIRS infrared instrument onboard Aqua, and the SeaWinds scatterometer onboard QuikSCAT. Both are JPL-managed instruments. AIRS data are used to create global three-dimensional maps of temperature, humidity and clouds, while scatterometers measure surface wind speed and direction over the ocean. The red vectors in the image show Frances' surface winds as measured by SeaWinds on QuikSCAT. The background colors show the temperature of clouds and surface as viewed in the infrared by AIRS, with cooler areas pushing to purple and warmer areas are pushing to red. The color scale on the right gives the temperatures in degrees Kelvin. (The top of the scale, 320 degrees Kelvin, corresponds to 117 degrees Fahrenheit, and the bottom, 180 degrees K is -135 degrees F.) The powerful circulation of this storm is evident from the combined data as well as the development of a clearly-defined central 'eye'. The infrared signal does not penetrate through clouds, so the light blue areas reveal the cold clouds tops associated with strong thunderstorms embedded within the storm. In cloud-free areas the infrared signal comes from Earth's surface, revealing warmer temperatures. The power of the SeaWinds scatterometer data set lies in its ability to generate global maps of wind speed and direction, giving us a snapshot of how the atmosphere is circulating. Weather prediction centers, including the Tropical Prediction Center - a branch of NOAA that monitors the creation of ocean-born storms, use scatterometer data to help it 'see' where these storms are brewing so that warnings can be issued and the storms, with often erratic motions, can be tracked. While the SeaWinds instrument isn't designed to gather hurricane data, having difficulty seeing the surface in heavy rain, it's data can be used in combination with other data sets to give us an insight into these storms. In this combination image

  8. Using Large-Eddy Simulations to Define Spectral and Coherence Characteristics of the Hurricane Boundary Layer for Wind-Energy Applications

    Science.gov (United States)

    Worsnop, Rochelle P.; Bryan, George H.; Lundquist, Julie K.; Zhang, Jun A.

    2017-06-01

    Offshore wind-energy development is planned for regions where hurricanes commonly occur, such as the USA Atlantic Coast. Even the most robust wind-turbine design (IEC Class I) may be unable to withstand a Category-2 hurricane (hub-height wind speeds >50 m s^{-1} ). Characteristics of the hurricane boundary layer that affect the structural integrity of turbines, especially in major hurricanes, are poorly understood, primarily due to a lack of adequate observations that span typical turbine heights (hurricane at high spatial (10 m) and temporal (0.1 s) resolution. By comparison with unique flight-level observations from a field project, we find that a relatively simple configuration of the Cloud Model I model accurately represents the properties of Hurricane Isabel (2003) in terms of mean wind speeds, wind-speed variances, and power spectra. Comparisons of power spectra and coherence curves derived from our hurricane simulations to those used in current turbine design standards suggest that adjustments to these standards may be needed to capture characteristics of turbulence seen within the simulated hurricane boundary layer. To enable improved design standards for wind turbines to withstand hurricanes, we suggest modifications to account for shifts in peak power to higher frequencies and greater spectral coherence at large separations.

  9. Satellite sar detection of hurricane helene (2006)

    DEFF Research Database (Denmark)

    Ju, Lian; Cheng, Yongcun; Xu, Qing

    2013-01-01

    In this paper, the wind structure of hurricane Helene (2006) over the Atlantic Ocean is investigated from a C-band RADARSAT-1 synthetic aperture radar (SAR) image acquired on 20 September 2006. First, the characteristics, e.g., the center, scale and area of the hurricane eye (HE) are determined....... There is a good agreement between the SAR-estimated HE center location and the best track data from the National Hurricane Center. The wind speeds at 10 m above the ocean surface are also retrieved from the SAR data using the geophysical model function (GMF), CMOD5, and compared with in situ wind speed...... observations from the stepped frequency microwave radiometer (SFMR) on NOAA P3 aircraft. All the results show the capability of hurricane monitoring by satellite SAR. Copyright © 2013 by the International Society of Offshore and Polar Engineers (ISOPE)....

  10. Modelling hurricane exposure and wind speed on a mesoclimate scale: a case study from Cusuco NP, Honduras.

    Directory of Open Access Journals (Sweden)

    Sven P Batke

    Full Text Available High energy weather events are often expected to play a substantial role in biotic community dynamics and large scale diversity patterns but their contribution is hard to prove. Currently, observations are limited to the documentation of accidental records after the passing of such events. A more comprehensive approach is synthesising weather events in a location over a long time period, ideally at a high spatial resolution and on a large geographic scale. We provide a detailed overview on how to generate hurricane exposure data at a meso-climate level for a specific region. As a case study we modelled landscape hurricane exposure in Cusuco National Park (CNP, Honduras with a resolution of 50 m×50 m patches. We calculated actual hurricane exposure vulnerability site scores (EVVS through the combination of a wind pressure model, an exposure model that can incorporate simple wind dynamics within a 3-dimensional landscape and the integration of historical hurricanes data. The EVSS was calculated as a weighted function of sites exposure, hurricane frequency and maximum wind velocity. Eleven hurricanes were found to have affected CNP between 1995 and 2010. The highest EVSS's were predicted to be on South and South-East facing sites of the park. Ground validation demonstrated that the South-solution (i.e. the South wind inflow direction explained most of the observed tree damage (90% of the observed tree damage in the field. Incorporating historical data to the model to calculate actual hurricane exposure values, instead of potential exposure values, increased the model fit by 50%.

  11. Modelling hurricane exposure and wind speed on a mesoclimate scale: a case study from Cusuco NP, Honduras.

    Science.gov (United States)

    Batke, Sven P; Jocque, Merlijn; Kelly, Daniel L

    2014-01-01

    High energy weather events are often expected to play a substantial role in biotic community dynamics and large scale diversity patterns but their contribution is hard to prove. Currently, observations are limited to the documentation of accidental records after the passing of such events. A more comprehensive approach is synthesising weather events in a location over a long time period, ideally at a high spatial resolution and on a large geographic scale. We provide a detailed overview on how to generate hurricane exposure data at a meso-climate level for a specific region. As a case study we modelled landscape hurricane exposure in Cusuco National Park (CNP), Honduras with a resolution of 50 m×50 m patches. We calculated actual hurricane exposure vulnerability site scores (EVVS) through the combination of a wind pressure model, an exposure model that can incorporate simple wind dynamics within a 3-dimensional landscape and the integration of historical hurricanes data. The EVSS was calculated as a weighted function of sites exposure, hurricane frequency and maximum wind velocity. Eleven hurricanes were found to have affected CNP between 1995 and 2010. The highest EVSS's were predicted to be on South and South-East facing sites of the park. Ground validation demonstrated that the South-solution (i.e. the South wind inflow direction) explained most of the observed tree damage (90% of the observed tree damage in the field). Incorporating historical data to the model to calculate actual hurricane exposure values, instead of potential exposure values, increased the model fit by 50%.

  12. Forest impact estimated with NOAA AVHRR and landsat TM data related to an empirical hurricane wind-field distribution

    Science.gov (United States)

    Ramsey, Elijah W.; Hodgson, M.E.; Sapkota, S.K.; Nelson, G.A.

    2001-01-01

    An empirical model was used to relate forest type and hurricane-impact distribution with wind speed and duration to explain the variation of hurricane damage among forest types along the Atchafalaya River basin of coastal Louisiana. Forest-type distribution was derived from Landsat Thematic Mapper image data, hurricane-impact distribution from a suite of transformed advanced very high resolution radiometer images, and wind speed and duration from a wind-field model. The empirical model explained 73%, 84%, and 87% of the impact variances for open, hardwood, and cypress-tupelo forests, respectively. These results showed that the estimated impact for each forest type was highly related to the duration and speed of extreme winds associated with Hurricane Andrew in 1992. The wind-field model projected that the highest wind speeds were in the southern basin, dominated by cypress-tupelo and open forests, while lower wind speeds were in the northern basin, dominated by hardwood forests. This evidence could explain why, on average, the impact to cypress-tupelos was more severe than to hardwoods, even though cypress-tupelos are less susceptible to wind damage. Further, examination of the relative importance of wind speed in explaining the impact severity to each forest type showed that the impact to hardwood forests was mainly related to tropical-depression to tropical-storm force wind speeds. Impacts to cypress-tupelo and open forests (a mixture of willows and cypress-tupelo) were broadly related to tropical-storm force wind speeds and by wind speeds near and somewhat in excess of hurricane force. Decoupling the importance of duration from speed in explaining the impact severity to the forests could not be fully realized. Most evidence, however, hinted that impact severity was positively related to higher durations at critical wind speeds. Wind-speed intervals, which were important in explaining the impact severity on hardwoods, showed that higher durations, but not the

  13. Vertical Profiles of the 3-D Wind Velocity Retrieved from Multiple Wind Lidars Performing Triple Range-Height-Indicator Scans

    Energy Technology Data Exchange (ETDEWEB)

    Debnath, Mithu; Iungo, G. Valerio; Ashton, Ryan; Brewer, W. Alan; Choukulkar, Aditya; Delgado, Ruben; Lundquist, Julie K.; Shaw, William J.; Wilczak, James M.; Wolfe, Daniel

    2017-02-06

    Vertical profiles of 3-D wind velocity are retrieved from triple range-height-indicator (RHI) scans performed with multiple simultaneous scanning Doppler wind lidars. This test is part of the eXperimental Planetary boundary layer Instrumentation Assessment (XPIA) campaign carried out at the Boulder Atmospheric Observatory. The three wind velocity components are retrieved and then compared with the data acquired through various profiling wind lidars and high-frequency wind data obtained from sonic anemometers installed on a 300 m meteorological tower. The results show that the magnitude of the horizontal wind velocity and the wind direction obtained from the triple RHI scans are generally retrieved with good accuracy. However, poor accuracy is obtained for the evaluation of the vertical velocity, which is mainly due to its typically smaller magnitude and to the error propagation connected with the data retrieval procedure and accuracy in the experimental setup.

  14. Applications of AMSR-E Measurements for Tropical Cyclone Predictions Part Ⅰ: Retrieval of Sea Surface Temperature and Wind Speed

    Institute of Scientific and Technical Information of China (English)

    Banghua YAN; Fuzhong WENG

    2008-01-01

    Existing satellite microwave algorithms for retrieving Sea Surface Temperature(Sst)and wind(SSW)are applicable primarily for non-raining cloudy conditions.With the launch of the Earth Observing System (EOS)Aqua satellite in 2002,the Advanced Microwave Scanning Radiometer(AMSR-E)onboard provides some unique measurements at lower frequencies which are sensitive to ocean surface parameters under ad-verse weather conditions.In this study,a new algorithm is developed to derive SST and SSW for hurricane predictions such as hurricane vortex analysis from the AMSR-E measurements at 6.925 and 10.65 GHz.In the algorithm,the effects of precipitation emission and scattering on the measurements are properly taken into account.The algorithm performances are evaluated with buoy measurements and aircraft dropsonde data.It is found that the root mean square (RMS) errors for SST and SSW are about 1.8K and 1.9m s(-1),respectively,when the results are compared with the buoy data over open oceans under precipitating clouds (e.g.,its liquid water path is larger than 0.5 mm),while they are 1.1 K for SST and 2.0 ms(-1)for SSW,respectively,when the retrievals are validated against the dropsonde measurements over warm oceans.These results indicate that our newly developed algorithm catl provide some critical surface information for trop-ical cycle predictions.Currently,this newly developed algorithm has been implemented into the hybrid variational scheme for the hurricane vortex analysis to provide predictions of SST and SSW fields.

  15. Retrieval of vertical wind profiles during monsoon from satellite observed winds over the Indian Ocean using complex EOF analysis

    Indian Academy of Sciences (India)

    C M Kishtawal; Sujit Basu; S Karthikeyan

    2001-03-01

    The aim of this paper is to study the feasibility of deriving vertical wind profiles from current satellite observations. With this aim, we carried out complex empirical orthogonal function (CEOF) analysis of a large number of radiosonde observations of wind profiles over the Indian Ocean during the monsoon months. It has been found that the first two CEOFs explain 67% of the total variance in wind fields. While the first principal component is well correlated with the winds at 850 mb ( = 0.80), the second one is highly correlated with winds at 200 mb ( = 0.89). This analysis formed the basis of a retrieval algorithm which ensures the retrieval of vertical profiles of winds using satellite tracked cloud motion vector winds. Under the assumption that accurate measurements of wind are available at the above mentioned levels, the r.m.s. error of retrieval of each component of wind is estimated to range between 2ms-1 and 6ms-1 at different levels, which is much less than the natural variance of winds at these levels. For a better visualization of retrieval, we have provided retrieved and true wind profiles side by side for four typical synoptic conditions during the monsoon season.

  16. Retrieval of ocean surface wind stress and drag coefficient from spaceborne SAR

    Institute of Scientific and Technical Information of China (English)

    杨劲松; 黄韦艮; 周长宝

    2001-01-01

    A model for retrieval of wind stress and drag coefficient on the sea surface with the data measured by spacebome synthetic aperture radar (SAR) has been developed based on the SAR imaging mechanisms of ocean surface capillary waves and short gravity waves. This model consists of radiometric calibration, wind speed retrieval and wind stress and drag coefficient calculation. A Radarsat SAR image has been used to calculate wind stress and drag coeffi cient. Good results have been achieved.

  17. Ocean's response to Hurricane Frances and its implications for drag coefficient parameterization at high wind speeds

    KAUST Repository

    Zedler, S. E.

    2009-04-25

    The drag coefficient parameterization of wind stress is investigated for tropical storm conditions using model sensitivity studies. The Massachusetts Institute of Technology (MIT) Ocean General Circulation Model was run in a regional setting with realistic stratification and forcing fields representing Hurricane Frances, which in early September 2004 passed east of the Caribbean Leeward Island chain. The model was forced with a NOAA-HWIND wind speed product after converting it to wind stress using four different drag coefficient parameterizations. Respective model results were tested against in situ measurements of temperature profiles and velocity, available from an array of 22 surface drifters and 12 subsurface floats. Changing the drag coefficient parameterization from one that saturated at a value of 2.3 × 10 -3 to a constant drag coefficient of 1.2 × 10-3 reduced the standard deviation difference between the simulated minus the measured sea surface temperature change from 0.8°C to 0.3°C. Additionally, the standard deviation in the difference between simulated minus measured high pass filtered 15-m current speed reduced from 15 cm/s to 5 cm/s. The maximum difference in sea surface temperature response when two different turbulent mixing parameterizations were implemented was 0.3°C, i.e., only 11% of the maximum change of sea surface temperature caused by the storm. Copyright 2009 by the American Geophysical Union.

  18. Ocean's response to Hurricane Frances and its implications for drag coefficient parameterization at high wind speeds

    Science.gov (United States)

    Zedler, S. E.; Niiler, P. P.; Stammer, D.; Terrill, E.; Morzel, J.

    2009-04-01

    The drag coefficient parameterization of wind stress is investigated for tropical storm conditions using model sensitivity studies. The Massachusetts Institute of Technology (MIT) Ocean General Circulation Model was run in a regional setting with realistic stratification and forcing fields representing Hurricane Frances, which in early September 2004 passed east of the Caribbean Leeward Island chain. The model was forced with a NOAA-HWIND wind speed product after converting it to wind stress using four different drag coefficient parameterizations. Respective model results were tested against in situ measurements of temperature profiles and velocity, available from an array of 22 surface drifters and 12 subsurface floats. Changing the drag coefficient parameterization from one that saturated at a value of 2.3 × 10-3 to a constant drag coefficient of 1.2 × 10-3 reduced the standard deviation difference between the simulated minus the measured sea surface temperature change from 0.8°C to 0.3°C. Additionally, the standard deviation in the difference between simulated minus measured high pass filtered 15-m current speed reduced from 15 cm/s to 5 cm/s. The maximum difference in sea surface temperature response when two different turbulent mixing parameterizations were implemented was 0.3°C, i.e., only 11% of the maximum change of sea surface temperature caused by the storm.

  19. Retrieval algorithm of sea surface wind vectors for WindSat based on a simple forward model

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yili

    2013-01-01

    WindSat/Coriolis is the first satellite-borne polarimetric microwave radiometer,which aims to improve the potential of polarimetric microwave radiometry for measuring sea surface wind vectors from space.In this paper,a wind vector retrieval algorithm based on a novel and simple forward model was developed for WindSat.The retrieval algorithm of sea surface wind speed was developed using multiple linear regression based on the simulation dataset of the novel forward model.Sea surface wind directions that minimize the difference between simulated and measured values of the third and fourth Stokes parameters were found using maximum likelihood estimation,by which a group of ambiguous wind directions was obtained.A median filter was then used to remove ambiguity of wind direction.Evaluated with sea surface wind speed and direction data from the U.S.National Data Buoy Center (NDBC),root mean square errors are 1.2 m/s and 30° for retrieved wind speed and wind direction,respectively.The evaluation results suggest that the simple forward model and the retrieval algorithm are practicable for near-real time applications,without reducing accuracy.

  20. The main forest inventory characteristics of the stands damaged by hurricane winds in the southern taiga subzone (Kostroma Oblast

    Directory of Open Access Journals (Sweden)

    I. N. Petukhov

    2016-08-01

    Full Text Available In June and July 2010 in Yaroslavl, Vologda and Kostroma regions, as a result of exposure to hurricane winds, recorded several violations of extensive forest cover in the form of windfalls and windbreaks (Krylov et al., 2012; Petukhov, Nemchinova, 2014. Retrospective analysis on the basis of remote sensing data for the period 1984–2011’s was conducted. It showed, that among the 21st dedicated mass windfall within the Kostroma region and border areas, windfall July 2010 is unique in the magnitude of the total area of disturbed forest cover. According to our estimates, derived from the analysis of remote sensing (RS, its area was more than 60 thousand Ha, which is four times the average annual area of clear felling, in particular, in the Kostroma region (Petukhov, Nemchinova, 2014. In addition to determining the areas of windfall violations of forest cover, based on forest inventory data and remote sensing data analyzed taxation characteristics of forest stands affected by the impact of the seven gale-force winds within the territory of the Kostroma region. The analysis revealed the following trends in hurricane-force winds damaged trees: for parameters such as completeness, forest type and site class is observed relatively uniform stands hurricane wind damage; I.e., we have not found an association between the degree (probability of forest stands damaged data and taxation values data. An exception is the age, height, and in some cases, the predominant species plantations. Plantations dominated by spruce in the stand proved to be somewhat less, but with a predominance of pine – more resistant to hurricane winds, compared to other tree species. Selectivity is also observed for breach of stands older than 40 years and a height of over 16 meters, which is possibly related to the morphological and physiological features of the trees of a given age and height.

  1. Estimation of the CO2 fluxes between the ocean and atmosphere for the hurricane wind forces using remote sensing data.

    Science.gov (United States)

    Sergeev, Daniil; Soustova, Irina; Balandina, Galina

    2017-04-01

    CO2 transfer between the hydrosphere and atmosphere in the boundary layer is an important part of the global cycle of the main greenhouse gas. Gas flux is determined by the difference of the partial pressures of the gas between the atmosphere and hydrosphere, near the border, as well as to a large extent processes involving turbulent boundary layer. The last is usually characterized by power dependence on the equivalent wind speed (10-m height). Hurricane-force winds lead to intensive wave breaking, with formation of spray in the air, and bubbles in the water. Such multiphase turbulent processes at the interface strongly intensify gas transfer. Currently, data characterizing the dependence of the gas exchange of the wind speed for the hurricane conditions demonstrate a strong variation. On the other hand there is an obvious problem of obtaining reliable data on the wind speed. Widely used reanalysis data typically underestimate wind speed, due to the low spatial and temporal resolution One of the most promising ways to measure near water wind speed is the use of the data of remote sensing. The present study used technique to obtain near water wind speed based on the processing of remote sensing of the ocean surface data obtained with C-band scattermeter of RADARSAT using geophysical model function, developed in a laboratory conditions for a wide range of wind speeds, including hurricanes (see [1]). This function binds wind speed with effective radar cross-section in cross-polarized mode. We used two different parameterizations of gas transfer velocity of the wind speed. Widely used in [2], and obtained by processing results of recent experiment in modeling winds up to hurricane on wind-wave facility [3]. The new method of calculating was tested by the example of hurricane Earl image (09.2010). Estimates showed 13-18 times excess CO2 fluxes rates in comparison with monitoring data NOAA (see. [4]). 1. Troitskaya Yu., Abramov V., Ermoshkin A., Zuikova E., Kazakov V

  2. A Method for Sea Surface Wind Field Retrieval from SAR Image Mode Data

    Institute of Scientific and Technical Information of China (English)

    SHAO Weizeng; SUN Jian; GUAN Changlong; SUN Zhanfeng

    2014-01-01

    To retrieve wind field from SAR images, the development for surface wind field retrieval from SAR images based on the improvement of new inversion model is present. Geophysical Model Functions (GMFs) have been widely applied for wind field retrieval from SAR images. Among them CMOD4 has a good performance under low and moderate wind conditions. Although CMOD5 is developed recently with a more fundamental basis, it has ambiguity of wind speed and a shape gradient of normalized radar cross section under low wind speed condition. This study proposes a method of wind field retrieval from SAR image by com-bining CMOD5 and CMOD4 Five VV-polarisation RADARSAT2 SAR images are implemented for validation and the retrieval re-sults by a combination method (CMOD5 and CMOD4) together with CMOD4 GMF are compared with QuikSCAT wind data. The root-mean-square error (RMSE) of wind speed is 0.75 m s-1 with correlation coefficient 0.84 using the combination method and the RMSE of wind speed is 1.01 m s-1 with correlation coefficient 0.72 using CMOD4 GMF alone for those cases. The proposed method can be applied to SAR image for avoiding the internal defect in CMOD5 under low wind speed condition.

  3. Data and numerical analysis of astronomic tides, wind-waves, and hurricane storm surge along the northern Gulf of Mexico

    Science.gov (United States)

    Bilskie, M. V.; Hagen, S. C.; Medeiros, S. C.; Cox, A. T.; Salisbury, M.; Coggin, D.

    2016-05-01

    The northern Gulf of Mexico (NGOM) is a unique geophysical setting for complex tropical storm-induced hydrodynamic processes that occur across a variety of spatial and temporal scales. Each hurricane includes its own distinctive characteristics and can cause unique and devastating storm surge when it strikes within the intricate geometric setting of the NGOM. While a number of studies have explored hurricane storm surge in the NGOM, few have attempted to describe storm surge and coastal inundation using observed data in conjunction with a single large-domain high-resolution numerical model. To better understand the oceanic and nearshore response to these tropical cyclones, we provide a detailed assessment, based on field measurements and numerical simulation, of the evolution of wind waves, water levels, and currents for Hurricanes Ivan (2004), Dennis (2005), Katrina (2005), and Isaac (2012), with focus on Mississippi, Alabama, and the Florida Panhandle coasts. The developed NGOM3 computational model describes the hydraulic connectivity among the various inlet and bay systems, Gulf Intracoastal Waterway, coastal rivers and adjacent marsh, and built infrastructure along the coastal floodplain. The outcome is a better understanding of the storm surge generating mechanisms and interactions among hurricane characteristics and the NGOM's geophysical configuration. The numerical analysis and observed data explain the ˜2 m/s hurricane-induced geostrophic currents across the continental shelf, a 6 m/s outflow current during Ivan, the hurricane-induced coastal Kelvin wave along the shelf, and for the first time a wealth of measured data and a detailed numerical simulation was performed and was presented for Isaac.

  4. Neural network wind retrieval from ERS -1/2 scatterometer data

    Institute of Scientific and Technical Information of China (English)

    LIN Mingsen; SONG Xingai; JIANG Xingwei

    2006-01-01

    A neural network methodology is presented to retrieve wind vectors from ERS - 1/2 scatterometer data. The wind directional ambiguities are eliminated by a circular median filter algorithm. All data come from ERS - 1/2 scatterometer data collocated pairs with CMCD4 vector. Comparing the results with CMCD4 and ECMWF wind vector,they agree well, which indicates that it is possible to extract wind vector from the ERS-1/2 scatterometer with the neural network method.

  5. An Integrating VAP Method for Single-Doppler Radar Wind Retrieval

    Institute of Scientific and Technical Information of China (English)

    LIANG Xudong; WANG Bin

    2009-01-01

    Some traditional methods, such as the velocity-azimuth display (VAD) and the velocity-azimuth pro-cessing (VAP), have been widely used to retrieve the 3-D wind field from single-Doppler radar data because of their relative conceptual and practical simplicity. The advantage of VAD is that it is not affected by small-scale perturbations of the radial wind along the azimuth, to which the VAP method is very sensitive. Nevertheless, the spatial resolution of the VAD method is very poor compared to the VAP method. We show, in this study, that these two retrieval methods are actually related with each other and they are two special applications of a retrieval function based on the azimuthal uniform-wind assumption for a given azimuthal interval [θ1,θ2]. When using this retrieval function to retrieve wind fields, the azimuthal interval used in retrieval can be adjusted according to the requirement of smoothness or resolution. The larger (smaller) the azimuthal interval is, the coarser (finer) the horizontal resolution of retrieved wind field is, and the more insensitive (sensitive) the retrieval method is to small-scale perturbations. Because the full information within the azimuthal interval [θ1,θ2], instead of the information at two terminal points only, i.e., azimuths θ1 and θ2, is used to retrieve the wind fields, this method is referred to as the integrating VAP (IVAP) method, wherein the horizontal wind field is retrieved by using the Doppler velocity over the part of circumference, delimited by the given azimuthal interval times the scan radius. By contrast, the VAP method uses only the velocities at two terminal points of the given azimuthal interval. Therefore, the IVAP method has a filtering function, and the filtering rate can be controlled by adjusting the azimuthal interval. The filter such as that used in the pre-processing of the VAP method is no longer necessary for the IVAP method. When the retrieval azimuthal interval is as large as a whole

  6. Impact of the Assimilation of Hyperspectral Infrared Retrieved Profiles on Advanced Weather and Research Model Simulations of a Non-Convective Wind Event

    Science.gov (United States)

    Berndt, E. B.; Zavodsky, B. T.; Folmer, M. J.; Jedlovec, G. J.

    2014-01-01

    Non-convective wind events commonly occur with passing extratropical cyclones and have significant societal and economic impacts. Since non-convective winds often occur in the absence of specific phenomena such as a thunderstorm, tornado, or hurricane, the public are less likely to heed high wind warnings and continue daily activities. Thus non-convective wind events result in as many fatalities as straight line thunderstorm winds. One physical explanation for non-convective winds includes tropopause folds. Improved model representation of stratospheric air and associated non-convective wind events could improve non-convective wind forecasts and associated warnings. In recent years, satellite data assimilation has improved skill in forecasting extratropical cyclones; however errors still remain in forecasting the position and strength of extratropical cyclones as well as the tropopause folding process. The goal of this study is to determine the impact of assimilating satellite temperature and moisture retrieved profiles from hyperspectral infrared (IR) sounders (i.e. Atmospheric Infrared Sounder (AIRS), Cross-track Infrared and Microwave Sounding Suite (CrIMSS), and Infrared Atmospheric Sounding Interferometer (IASI)) on the model representation of the tropopause fold and an associated high wind event that impacted the Northeast United States on 09 February 2013. Model simulations using the Advanced Research Weather Research and Forecasting Model (ARW) were conducted on a 12-km grid with cycled data assimilation mimicking the operational North American Model (NAM). The results from the satellite assimilation run are compared to a control experiment (without hyperspectral IR retrievals), 32-km North American Regional Reanalysis (NARR) interpolated to a 12-km grid, and 13-km Rapid Refresh analyses.

  7. Two-Look Polarimetric (2LP) Microwave Radiometers for Ocean Vector Wind Retrieval

    Science.gov (United States)

    Wentz, F. J.; Hilburn, K. A.; Meissner, T.; Brown, S. E.

    2014-12-01

    This talk discusses the future utilization of two-look polarimetric (2LP) microwave radiometers for measuring the ocean surface wind vector. Potentially, these 2LP satellite radiometers offer two advantages over conventional scatterometers: unambiguous wind vector retrievals and low-cost. One concept for a 2LP radiometer is being developed by JPL and is called the Compact Ocean Wind Vector Radiometer (COWVR). A space demonstration of COWVR is planned for 2016 timeframe. To explore the potential of 2LP radiometers, we use the 11 years of WindSat observations as a testbed. We only use that portion of the WindSat swath that has both fore and aft observations. WindSat provides fully polarimetric observations (all four Stokes parameters) at 11, 19, and 37 GHz. This represents 12 independent channels for each of the two azimuth directions. A wind vector retrieval algorithm is developed to fully utilize this wide assortment of information. Since this analysis is based on actual observations, it provides a realistic picture of what to expect from future 2LP radiometers. To our knowledge, this is the first time that the combination of WindSat's fore and aft observations has been fully utilized for wind vector retrievals. In our talk we compare the 2LP wind vector retrieval performance with that of single-look polarimetric radiometers (i.e., WindSat standard product) and scatterometers. We provide basic statistics from a triple collocation between winds from WindSat, QuikScat, and NDBC/PMEL ocean moored buoys. The statistics include the standard deviation of the first ranked ambiguity direction, skill rate, and number of ambiguities. All available data from the common period of operation between WindSat and QuikScat (2003-2009) are used. We characterize the wind direction accuracy as a function of wind speed, and show how 2LP retrievals are able to extend the wind vector accuracy to lower wind speeds than previously considered possible for radiometers.

  8. Retrieval of Wind Speed Using an L-band Synthetic Aperture Radar

    DEFF Research Database (Denmark)

    Monaldo, Frank M.; Thompson, Donald R.; Badger, Merete

    2007-01-01

    Retrieval of wind speed using L-band synthetic aperture radar (SAR) is both an old and new endeavor. Although the Seasat L-band SAR in 1978 was not well calibrated, early results indicated a strong relationship between observed SAR image intensity and wind speed. The JERS-1 L-band SAR had limited...... usefulness over the ocean. Most recent wind retrievals from spaceborne SARs have been at C-band for ERS-1/2, Radarsat, and Envisat. With the launch of the sophisticated multi- polarization Phased Array L-band Synthetic Aperture Radar (PALSAR) on the Advanced Land Observing Satellite (ALOS), we renew...

  9. Geologic effects of hurricanes

    Science.gov (United States)

    Coch, Nicholas K.

    1994-08-01

    Hurricanes are intense low pressure systems of tropical origin. Hurricane damage results from storm surge, wind, and inland flooding from heavy rainfall. Field observations and remote sensing of recent major hurricanes such as Hugo (1989), Andrew (1992) and Iniki (1992) are providing new insights into the mechanisms producing damage in these major storms. Velocities associated with hurricanes include the counterclockwise vortex winds flowing around the eye and the much slower regional winds that steer hurricane and move it forward. Vectorial addition of theseof these two winds on the higher effective wind speed than on the left side. Coast-parallel hurricane tracks keep the weaker left side of the storm against the coast, whereas coast-normal tracks produce a wide swath of destruction as the more powerful right side of the storm cuts a swath of destruction hundreds of kilometers inland. Storm surge is a function of the wind speed, central pressure, shelf slope, shoreline configuration, and anthropogenic alterations to the shoreline. Maximum surge heights are not under the eye of the hurricane, where the pressure is lowest, but on the right side of the eye at the radius of maximum winds, where the winds are strongest. Flood surge occurs as the hurricane approaches land and drives coastal waters, and superimposed waves, across the shore. Ebb surge occurs when impounded surface water flows seaward as the storm moves inland. Flood and ebb surge damage have been greatly increased in recent hurricanes as a result of anthropogenic changes along the shoreline. Hurricane wind damage occurs on three scales — megascale, mesoscale and microscale. Local wind damage is a function of wind speed, exposure and structural resistance to velocity pressure, wind drag and flying debris. Localized extreme damage is caused by gusts that can locally exceed sustained winds by a factor of two in areas where there is strong convective activity. Geologic changes occuring in hurricanes

  10. A comparative analysis of two wind velocity retrieval techniques by using a single Doppler radar

    Directory of Open Access Journals (Sweden)

    H.-C. Lim

    2009-05-01

    Full Text Available This study compares the theoretical basis of the two wind velocity retrieval methods, Velocity Azimuth Display (VAD and Velocity Area Display (VARD by using data obtained by a single Doppler radar. Two pre-assumed shapes of the wind velocity distribution with altitude are considered, uniform and parabolic. The former presents an approximation of the non-sheared or low-sheared wind flow in the upper troposphere, while the latter is a simplified representation of the Atmospheric Boundary Layer (ABL in lower troposphere or high-sheared wind flow at the edges of the tropospheric jet streams. Both techniques for the wind velocity retrieval considered in this study are reformulated in order to get more precise information on the wind velocity components. An algorithm is proposed to decrease the uncertainty in retrieving by evaluating the coefficients of the polynomial equation and applying a transfer function with respect to the angle formed between the wind flow direction and direction of radar beam. It is concluded that, provided the formulated transformation functions are used, the application of the VAD and VARD techniques to the single-Doppler data may be an invaluable tool for solving various climate and wind engineering problems.

  11. Comparison of Geophysical Model Functions for SAR Wind Speed Retrieval in Japanese Coastal Waters

    Directory of Open Access Journals (Sweden)

    Merete Badger

    2013-04-01

    Full Text Available This work discusses the accuracies of geophysical model functions (GMFs for retrieval of sea surface wind speed from satellite-borne Synthetic Aperture Radar (SAR images in Japanese coastal waters characterized by short fetches and variable atmospheric stability conditions. In situ observations from two validation sites, Hiratsuka and Shirahama, are used for comparison of the retrieved sea surface wind speeds using CMOD (C-band model4, CMOD_IFR2, CMOD5 and CMOD5.N. Of all the geophysical model functions (GMFs, the latest C-band GMF, CMOD5.N, has the smallest bias and root mean square error at both sites. All of the GMFs exhibit a negative bias in the retrieved wind speed. In order to understand the reason for this bias, all SAR-retrieved wind speeds are separated into two categories: onshore wind (blowing from sea to land and offshore wind (blowing from land to sea. Only offshore winds were found to exhibit the large negative bias, and short fetches from the coastline may be a possible reason for this. Moreover, it is clarified that in both the unstable and stable conditions, CMOD5.N has atmospheric stability effectiveness, and can keep the same accuracy with CMOD5 in the neutral condition. In short, at the moment, CMOD5.N is thought to be the most promising GMF for the SAR wind speed retrieval with the atmospheric stability correction in Japanese coastal waters, although there is ample room for future improvement for the effect from short fetch.

  12. Study on the Variational Assimilation Technique for the Retrieval of Wind Fields from Doppler Radar Data

    Institute of Scientific and Technical Information of China (English)

    WAN Qilin; XUE Jishan; ZHUANG Shiyu

    2006-01-01

    This paper introduces a variational assimilation technique for the retrieval of wind fields from Doppler radar data. The assimilated information included both the radial velocity (RV) and the movement of radar echo. In this assimilation technique, the key is transforming the movement of radar echo to a new radar measuring variable- "apparent velocity" (AV). Thus, the information of wind is added, and the indeterminacy of recovering two-dimensional wind only by AV was overcome effectively by combining RV with AV. By means of CMA GRAPES-3Dvar and CINRAD data, some experiments were performed. The results show that the method of retrieval of wind fields is useful in obtaining the construction of the weather system.

  13. Earth, wind, and fire: Wildfire risk perceptions in a hurricane-prone environment

    Science.gov (United States)

    Soren M. Newman; Matthew S. Carroll; Pamela J. Jakes; Daniel R. Williams; Lorie L. Higgins

    2014-01-01

    Wildfire is one of several potential disturbances that could have extraordinary impacts on individuals and communities in fire-prone areas. In this article we describe disturbance risk perceptions from interviews with residents in three Florida communities that face significant wildfire and hurricane risk. Although they live in areas characterized by emergency managers...

  14. Surviving Hurricane Katrina: Winds of Change Transform a New Orleans Addiction Treatment Agency

    Science.gov (United States)

    Toriello, Paul J.; Pedersen-Wasson, Else; Crisham, Erin M.; Ellis, Robert; Morse, Patricia; Morse, Edward V.

    2007-01-01

    Hurricane Katrina's impact on the operations of the largest residential, addiction treatment organization in New Orleans is described. Pre- and post-Katrina experiences are discussed and augmented with organizational performance data. Suggestions for future research are provided. (Contains 4 figures.)

  15. Preliminary Assessment of Wind and Wave Retrieval from Chinese Gaofen-3 SAR Imagery.

    Science.gov (United States)

    Shao, Weizeng; Sheng, Yexin; Sun, Jian

    2017-07-25

    The Chinese Gaofen-3 (GF-3) synthetic aperture radar (SAR) launched by the China Academy of Space Technology (CAST) has operated at C-band since September 2016. To date, we have collected 16/42 images in vertical-vertical (VV)/horizontal-horizontal (HH) polarization, covering the National Data Buoy Center (NDBC) buoy measurements of the National Oceanic and Atmospheric Administration (NOAA) around U.S. western coastal waters. Wind speeds from NDBC in situ buoys are up to 15 m/s and buoy-measured significant wave height (SWH) has ranged from 0.5 m to 3 m. In this study, winds were retrieved using the geophysical model function (GMF) together with the polarization ratio (PR) model and waves were retrieved using a new empirical algorithm based on SAR cutoff wavelength in satellite flight direction, herein called CSAR_WAVE. Validation against buoy measurements shows a 1.4/1.9 m/s root mean square error (RMSE) of wind speed and a 24/23% scatter index (SI) of SWH for VV/HH polarization. In addition, wind and wave retrieval results from 166 GF-3 images were compared with the European Centre for Medium-Range Weather Forecasts (ECMWF) re-analysis winds, as well as the SWH from the WaveWatch-III model, respectively. Comparisons show a 2.0 m/s RMSE for wind speed with a 36% SI of SWH for VV-polarization and a 2.2 m/s RMSE for wind speed with a 37% SI of SWH for HH-polarization. Our work gives a preliminary assessment of the wind and wave retrieval results from GF-3 SAR images for the first time and will provide guidance for marine applications of GF-3 SAR.

  16. Using Surface Pressure To Improve Tropical Cyclone /Surface Wind Retrievals From SAR

    Science.gov (United States)

    2012-03-19

    Jochen Horstmann of NATO Undersea Research Centre ( NURC ). GD and NURC have developed separate methods for estimating wind directions. The GD and NURC ...Working version of SLP retrieval code, including necessary PBL model developments, that is compatible with GD, NURC and WiSAR file formats (as well as for...installed at NURC and we have been experimenting with Horstmann to determine if it can (or should) be included as an integrated part of the NURC SAR wind

  17. Analysis of Hurricane Irene’s Wind Field Using the Advanced Research Weather Research and Forecast (WRF-ARW Model

    Directory of Open Access Journals (Sweden)

    Alfred M. Klausmann

    2014-01-01

    Full Text Available Hurricane Irene caused widespread and significant impacts along the U.S. east coast during 27–29 August 2011. During this period, the storm moved across eastern North Carolina and then tracked northward crossing into Long Island and western New England. Impacts included severe flooding from the mid-Atlantic states into eastern New York and western New England, widespread wind damage and power outages across a large portion of southern and central New England, and a major storm surge along portions of the Long Island coast. The objective of this study was to conduct retrospective simulations using the Advanced Research Weather Research and Forecast (WRF-ARW model in an effort to reconstruct the storm’s surface wind field during the period of 27–29 August 2011. The goal was to evaluate how to use the WRF modeling system as a tool for reconstructing the surface wind field from historical storm events to support storm surge studies. The results suggest that, with even modest data assimilation applied to these simulations, the model was able to resolve the detailed structure of the storm, the storm track, and the spatial surface wind field pattern very well. The WRF model shows real potential for being used as a tool to analyze historical storm events to support storm surge studies.

  18. Evaluation of ENVISAT ASAR data for sea surface wind retrieval in Hong Kong coastal waters of China

    Institute of Scientific and Technical Information of China (English)

    XU Qing; LIN Hui; ZHENG Quanan; XIU Peng; CHENG Yongcun; LIU Yuguang

    2008-01-01

    The C-band wind speed retrieval models,CMOD4,CMOD-IFR2,and CMODS were applied to retrieval of sea surface wind speeds from ENVISAT(European environmental satellite)ASAR(advanced synthetic aperture radar)data in the coastal waters near Hang Kong during a period from October 2005 to July 2007.The retrieved wind speeds are evaluated by comparing with buoy measurements and the QuikSCAT(quick scatterometer)wind products.The results show that the CMOD4 model gives the best performance at wind speeds lower than 15 m/s.The correlation coefficients with buoy and QuikSCAT winds are 0.781 and 0.896,respectively.The root mean square errors are the same 1.74m/s.Namely,the CMOD4 model is the best one for sea surface wind speed retrieval from ASAR data in the COastal waters near Hong Kong.

  19. Calibration of GNSS-R surface wind retrievals using the ERA analysis

    Science.gov (United States)

    Danielson, Rick; Johannessen, Johnny; Cardellach, Estel; Fabra, Fran; Catarino, Nuno

    2017-04-01

    The Space GNSS Receiver Remote Sensing Instrument (SGR-ReSI) of the TechDemoSat-1 (TDS-1) satellite collected and processed about half a million fast delivery wind speed retrievals. Exploring ways to validate these data provides an opportunity, not just to quantify, but also potentially to reduce wind speed retrieval errors (in an ordinary least squares sense) and thereby improve the correspondence between the data to be calibrated and an unknown target wind analysis. The ERA Interim analysis is employed as a calibrated reference for the TDS-1 wind speed retrievals. Simultaneous assessment of error in these two collocated data leads to a global (i.e., for all collocations) and local (i.e., as a function of wind speed) determinations of statistical properties characterizing bias (both additive and multiplicative), RMS error, and correlation with an unknown target analysis. The approach taken is widely referred to as the triple collocation method (Stoffelen 1998, McColl et al. 2014), where a simplifying assumption is that three wind estimates can be obtained from these two datasets (TDS-1 and ERA).

  20. Air Density And Wind Retrieval Using GOCE Data

    Science.gov (United States)

    Doornbos, E.; Bruinsma, S.; Fritsche, B.; Visser, P.; Van Den IJssel, J.; Encarnacao, J. Teixeira; Kern, M.

    2013-12-01

    In the GOCE+ Theme 3 project, ion thruster activation data from GOCE telemetry has been combined with the accelerometer and star camera data products, to derive a new set of data products on thermosphere neutral density and wind speed. These products can be seen as an ex- tension of the successful accelerometer-derived thermosphere density data sets from CHAMP and GRACE. It is the first time that such data, spanning multiple years, is available at a fixed and very low altitude and at a near constant orientation of the orbit plane with respect to the Sun. The data processing is based on an analysis of the aerodynamic accelerations acting on the satellite, and makes use of data from all instruments onboard the satellite. The following steps are involved: 1) estimation of the bias in the gradiometer common-mode accelerations using GPS tracking data, 2) conversion of ion thruster activation data to accelerations, 3) modelling of radiation pressure accelerations based on orbit and attitude information, 4) removal of radiation pressure and ion thruster accelerations from the common-mode acceleration data, to arrive at the observed aerodynamic accelerations, 5) iterative adjustment of wind direction and density inputs of an aerodynamic model of the satellite, until the modelled aerodynamic accelerations match the observations. The resulting density and wind observations are made available in the form of time series and grids. These data can be applied in investigations of solar-terrestrial physics, as well as for the improvement and validation of models used in space operations.

  1. Comparison of Geophysical Model Functions for SAR Wind Speed Retrieval in Japanese Coastal Waters

    DEFF Research Database (Denmark)

    Takeyama, Yuko; Ohsawa, Teruo; Kozai, Katsutoshi

    2013-01-01

    from two validation sites, Hiratsuka and Shirahama, are used for comparison of the retrieved sea surface wind speeds using CMOD (C-band model)4, CMOD_IFR2, CMOD5 and CMOD5.N. Of all the geophysical model functions (GMFs), the latest C-band GMF, CMOD5.N, has the smallest bias and root mean square error...

  2. Study of wind retrieval from space-borne infrared coherent lidar in cloudy atmosphere.

    Science.gov (United States)

    Baron, Philippe; Ishii, Shoken; Mizutani, Kohei; Okamoto, Kozo; Ochiai, Satoshi

    2015-04-01

    Future spaceborne tropospheric wind missions using infrared coherent lidar are currently being studied in Japan and in the United States [1,2]. The line-of-sight wind velocity is retrieved from the Doppler shift frequency of the signal returned by aerosol particles. However a large percentage (70-80%) of the measured single-shot intensity profiles are expected to be contaminated by clouds [3]. A large number of cloud contaminated profiles (>40%) will be characterized by a cloud-top signal intensity stronger than the aerosol signal by a factor of one order of magnitude, and by a strong attenuation of the signal backscattered from below the clouds. Profiles including more than one cloud layer are also expected. This work is a simulation study dealing with the impacts of clouds on wind retrieval. We focus on the three following points: 1) definition of an algorithm for optimizing the wind retrieval from the cloud-top signal, 2) assessment of the clouds impact on the measurement performance and, 3) definition of a method for averaging the measurements before the retrieval. The retrieval simulations are conducted considering the instrumental characteristics selected for the Japanese study: wavelength at 2 µm, PRF of 30 Hz, pulse power of 0.125 mJ and platform altitude between 200-400 km. Liquid and ice clouds are considered. The analysis uses data from atmospheric models and statistics of cloud effects derived from CALIPSO measurements such as in [3]. A special focus is put on the average method of the measurements before retrieval. Good retrievals in the mid-upper troposphere implie the average of measured single-range power spectra over large horizontal (100 km) and vertical (1 km) ranges. Large differences of signal intensities due to the presence of clouds and the clouds non-uniform distribution have to be taken into account when averaging the data to optimize the measurement performances. References: [1] S. Ishii, T. Iwasaki, M. Sato, R. Oki, K. Okamoto, T

  3. A level 2 wind speed retrieval algorithm for the CYGNSS mission

    Science.gov (United States)

    Clarizia, Maria Paola; Ruf, Christopher; O'Brien, Andrew; Gleason, Scott

    2014-05-01

    The NASA EV-2 Cyclone Global Navigation Satellite System (CYGNSS) is a spaceborne mission focused on tropical cyclone (TC) inner core process studies. CYGNSS consists of a constellation of 8 microsatellites, which will measure ocean surface wind speed in all precipitating conditions, including those experienced in the TC eyewall, and with sufficient frequency to resolve genesis and rapid intensification. It does so through the use of an innovative remote sensing technique, known as Global Navigation Satellite System-Reflectometry, or GNSS-R. GNSS-R uses signals of opportunity from navigation constellations (e.g. GPS, GLONASS, Galileo), scattered by the surface of the ocean, to retrieve the surface wind speed. The dense space-time sampling capabilities, the ability of L-band signals to penetrate well through rain, and the possibility of simple, low-cost/low-power GNSS receivers, make GNSS-R ideal for the CYGNSS goals. Here we present an overview of a Level 2 (L2) wind speed retrieval algorithm, which would be particularly suitable for CYGNSS, and could be used to estimate winds from GNSS-R in general. The approach makes use of two different observables computed from 1-second Level 2a (L2a) delay-Doppler Maps (DDMs) of radar cross section. The first observable is called Delay-Doppler Map Average (DDMA), and it's the averaged radar cross section over a delay-Doppler window around the DDM peak (i.e. the specular reflection point coordinate in delay and Doppler). The second is called the Leading Edge Slope (LES), and it's the leading edge of the Integrated Delay Waveform (IDW), obtained by integrating the DDM along the Doppler dimension. The observables are calculated over a limited range of delays and Doppler frequencies, to comply with baseline spatial resolution requirements for the retrieved winds, which in the case of CYGNSS is 25 km x 25 km. If the observable from the 1-second DDM corresponds to a resolution higher than the specified one, time-averaging between

  4. Stereoscopic Height and Wind Retrievals for Aerosol Plumes with the MISR INteractive eXplorer (MINX

    Directory of Open Access Journals (Sweden)

    David L. Nelson

    2013-09-01

    Full Text Available The Multi-angle Imaging SpectroRadiometer (MISR instrument aboard the Terra satellite acquires imagery at 275-m resolution at nine angles ranging from 0° (nadir to 70° off-nadir. This multi-angle capability facilitates the stereoscopic retrieval of heights and motion vectors for clouds and aerosol plumes. MISR’s operational stereo product uses this capability to retrieve cloud heights and winds for every satellite orbit, yielding global coverage every nine days. The MISR INteractive eXplorer (MINX visualization and analysis tool complements the operational stereo product by providing users the ability to retrieve heights and winds locally for detailed studies of smoke, dust and volcanic ash plumes, as well as clouds, at higher spatial resolution and with greater precision than is possible with the operational product or with other space-based, passive, remote sensing instruments. This ability to investigate plume geometry and dynamics is becoming increasingly important as climate and air quality studies require greater knowledge about the injection of aerosols and the location of clouds within the atmosphere. MINX incorporates features that allow users to customize their stereo retrievals for optimum results under varying aerosol and underlying surface conditions. This paper discusses the stereo retrieval algorithms and retrieval options in MINX, and provides appropriate examples to explain how the program can be used to achieve the best results.

  5. Stereoscopic Height and Wind Retrievals for Aerosol Plumes with the MISR INteractive eXplorer (MINX)

    Science.gov (United States)

    Nelson, D.L.; Garay, M.J.; Kahn, Ralph A.; Dunst, Ben A.

    2013-01-01

    The Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard the Terra satellite acquires imagery at 275-m resolution at nine angles ranging from 0deg (nadir) to 70deg off-nadir. This multi-angle capability facilitates the stereoscopic retrieval of heights and motion vectors for clouds and aerosol plumes. MISR's operational stereo product uses this capability to retrieve cloud heights and winds for every satellite orbit, yielding global coverage every nine days. The MISR INteractive eXplorer (MINX) visualization and analysis tool complements the operational stereo product by providing users the ability to retrieve heights and winds locally for detailed studies of smoke, dust and volcanic ash plumes, as well as clouds, at higher spatial resolution and with greater precision than is possible with the operational product or with other space-based, passive, remote sensing instruments. This ability to investigate plume geometry and dynamics is becoming increasingly important as climate and air quality studies require greater knowledge about the injection of aerosols and the location of clouds within the atmosphere. MINX incorporates features that allow users to customize their stereo retrievals for optimum results under varying aerosol and underlying surface conditions. This paper discusses the stereo retrieval algorithms and retrieval options in MINX, and provides appropriate examples to explain how the program can be used to achieve the best results.

  6. Hurricane Safety

    Science.gov (United States)

    ... English Hurricane Safety Checklist - Arabic Hurricane Safety Checklist - Chinese Hurricane Safety Checklist - French Hurricane Safety Checklist - Haitian ... Cross serves in the US, its territories and military installations around the world. Please try again. Your ...

  7. Offshore Wind Mapping Mediterranean area using SAR. A case study of retrieval around peninsular regions.

    Science.gov (United States)

    Calaudi, Rosamaria; Arena, Felice; Badger, Merete; Sempreviva, Anna Maria

    2013-04-01

    Satellite observations like Scatterometers e.g. QuickScat, and Synthetic Aperture Radars (SAR) of the ocean surface provide information about the spatial wind variability over large areas. This is very valuable, for mapping offshore wind resources for offshore wind farm installation, where the most suitable locations within a given region must be identified using at least 5 year wind data over the whole domain. This is a special issue in the Mediterranean, where spatial information is not readily available because buoys or masts are sparse, with long periods of missing data, and measurements represent only one point. Here, we focus on the SAR images that have the advantage of high spatial resolution (down to 100m) allowing to derive information close to the coast but with the disadvantage of low time resolution causing lack of information on regimes with low time scale. We retrieved SAR (ENVISAT ASAR scenes acquired in Wide Swath Mode-WSM-) wind speed in the Mediterranean from March 2002 to April 2012 using the Johns Hopkins University, Applied Physics Laboratory (JHU/APL) software APL/NOAA SAR Wind Retrieval System (ANSWRS version 2.0) (Monaldo 2000; Monaldo et al. 2006). The ANSWRS software produces per default wind speed fields initialized using wind directions determined by the Navy Operational Global Atmospheric Prediction System (NOGAPS) models interpolated in time and space to match the satellite data. NOGAPS data are available at 6-hour intervals mapped to a 1° latitude/longitude grid. Here, we present a case study in Calabria, a long, narrow and mountainous peninsula in South Italy that causes a significant wind conditions variability from one coast to the other. We considered a 10m mast, measuring hourly wind speed and direction located at the coastline at the harbor of the town Crotone, belonging to the marine network of sensors of ISPRA (Institute for Environmental Protection and Research). Three points of the SAR images were chosen at offshore

  8. Hurricane Science

    Science.gov (United States)

    Emanuel, Kerry

    2012-10-01

    Hurricanes provide beautiful examples of many of the key physical processes important in geophysical systems. They are rare natural examples of nearly perfect Carnot heat engines with an interesting wrinkle: They recycle much of their waste heat into the front end of the engine, thereby achieving greater wind speeds than would otherwise be possible. They are driven by surface enthalpy fluxes made possible by the thermodynamic disequilibrium between the earth's surface and atmosphere, a characteristic of radiative equilibrium in the presence of greenhouse gases. Their evolution, structure, and intensity all depend on turbulence near the ocean surface and in the outflow layer of the storm, high up in the atmosphere. In the course of this banquet, I will briefly describe these and other interesting aspects of hurricane physics, and also describe the role these storms have played in human history.

  9. Assessment and Analysis of QuikSCAT Vector Wind Products for the Gulf of Mexico: A Long-Term and Hurricane Analysis

    Directory of Open Access Journals (Sweden)

    Eurico D’Sa

    2008-03-01

    Full Text Available The northern Gulf of Mexico is a region that has been frequently impacted in recent years by natural disasters such as hurricanes. The use of remote sensing data such as winds from NASA’s QuikSCAT satellite sensor would be useful for emergency preparedness during such events. In this study, the performance of QuikSCAT products, including JPL’s latest Level 2B (L2B 12.5 km swath winds, were evaluated with respect to buoy-measured winds in the Gulf of Mexico for the period January 2005 to February 2007. Regression analyses indicated better accuracy of QuikSCAT’s L2B DIRTH, 12.5 km than the Level 3 (L3, 25 km wind product. QuikSCAT wind data were compared directly with buoy data keeping a maximum time interval of 20 min and spatial interval of 0.1° (≈10 km. R2 values for moderate wind speeds were 0.88 and 0.93 for L2B, and 0.75 and 0.89 for L3 for speed and direction, respectively. QuikSCAT wind comparisons for buoys located offshore were better than those located near the coast. Hurricanes that took place during 2002-06 were studied individually to obtain regressions of QuikSCAT versus buoys for those events. Results show QuikSCAT’s L2B DIRTH wind product compared well with buoys during hurricanes up to the limit of buoy measurements. Comparisons with the National Hurricane Center (NHC best track analyses indicated QuikSCAT winds to be lower than those obtained by NHC, possibly due to rain contamination, while buoy measurements appeared to be constrained at high wind speeds. This study has confirmed good agreement of the new QuikSCAT L2B product with buoy measurements and further suggests its potential use during extreme weather conditions in the Gulf of Mexico.

  10. Application of the Tikhonov regularization method to wind retrieval from scatterometer data I.Sensitivity analysis and simulation experiments

    Institute of Scientific and Technical Information of China (English)

    Zhong Jian; Huang Si-Xun; Du Hua-Dong; Zhang Liang

    2011-01-01

    Scatterometer is an instrument which provides all-day and large-scale wind field information, and its application especially to wind retrieval always attracts meteorologists. Certain reasons cause large direction error, so it is important to find where the error mainly comes. Does it mainly result from the background field, the normalized radar cross-section (NRCS) or the method of wind retrieval? It is valuable to research. First, depending on SDP2.0, the simulated 'true' NRCS is calculated from the simulated 'true' wind through the geophysical model function NSCAT2. The simulated background field is configured by adding a noise to the simulated 'true' wind with the non-divergence constraint. Also, the simulated 'measured' NRCS is formed by adding a noise to the simulated 'true' NRCS. Then, the sensitivity experiments are taken, and the new method of regularization is used to improve the ambiguity removal with simulation experiments. The results show that the accuracy of wind retrieval is more sensitive to the noise in the background than in the measured NRCS; compared with the two-dimensional variational (2DVAR) ambiguity removal method, the accuracy of wind retrieval can be improved with the new method of Tikhonov regularization through choosing an appropriate regularization parameter, especially for the case of large error in the background. The work will provide important information and a new method for the wind, retrieval with real data.

  11. Retrieval of Sea Surface Salinity and Wind from The NASA Soil Moisture Active Passive Mission Data

    Science.gov (United States)

    Yueh, S. H.; Fore, A.; Tang, W.; Hayashi, A.

    2015-12-01

    NASA's Soil Moisture Active Passive (SMAP) mission, the first Earth Science Decadal Survey mission, was launched January 31, 2015 to provide high-resolution, frequent-revisit global mapping of soil moisture. SMAP has two instruments, a polarimetric radiometer and a multi-polarization synthetic aperture radar. Both instruments operate at L-band frequencies (~ 1GHz) and share a single 6-m rotating mesh antenna, producing a fixed incidence angle conical scan at 40⁰ across a 1000-km swath and a 2-3 day global revisit. The SMAP SSS and ocean surface wind retrieval algorithm developed at the Jet Propulsion Laboratory leverages the QuikSCAT and Aquarius algorithms to account for the two-look geometry (fore and aft looks from the conical scan) and dual-polarization observations for simultaneous retrieval of SSS and wind speed. The retrieval algorithm has been applied to more than three months of SMAP radiometer data. Comparison with the European Center for Medium-Range Weather Forecasting (ECMWF) wind speed suggests that the SMAP wind speed reaches an accuracy of about 0.7 ms-1. The preliminary assessment of the SMAP SSS products gridded at 50 km spatial resolution and weekly intervals is promising. The spatial patterns of the SSS agree well with climatological distributions, but exhibit several unique spatial and temporal features. The temporal evolutions of freshwater plumes from several major rivers, such as the Amazon, Niger, Congo, Ganges, and Mississippi, are all consistent with the timing of rainy and dry seasons, indicated in the SMAP's soil moisture products. Rigorous accuracy assessment will be performed by comparison with in situ SSS data from buoys and ARGO floats. The SMAP evaluation products will be released to the public prior to November 2015.

  12. Retrieval of aerosol backscatter and extinction from airborne coherent Doppler wind lidar measurements

    Directory of Open Access Journals (Sweden)

    F. Chouza

    2015-02-01

    Full Text Available A novel method for calibration and quantitative aerosol optical properties retrieval from Doppler wind lidars (DWL is presented in this work. Due to the strong wavelength dependence of the atmospheric molecular backscatter and the low sensitivity of the coherent detection to spectrally broad signals, calibration methods for aerosol lidars cannot be applied to a coherent DWLs usually operating at wavelengths between 1.5–2 μm. Instead, concurrent measurements of an airborne DWL at 2 μm and the POLIS ground-based aerosol lidar at 532 nm are used in this work, in combination with sun photometer measurements, for the calibration and retrieval of aerosol backscatter and extinction profiles. The proposed method was applied to measurements from the SALTRACE experiment in June–July 2013, which aimed at quantifying the aerosol transport and change in aerosol properties from the Sahara desert to the Caribbean. The retrieved backscatter and extinction coefficient profiles from the airborne DWL are within 20% of POLIS aerosol lidar and CALIPSO satellite measurements. Thus the proposed method extends the capabilities of coherent DWL to measure profiles of the horizontal and vertical wind towards aerosol backscatter and extinction profiles, which is of high benefit for aerosol transport studies.

  13. Development of NEXRAD Wind Retrievals as Input to Atmospheric Dispersion Models

    Energy Technology Data Exchange (ETDEWEB)

    Fast, Jerome D.; Newsom, Rob K.; Allwine, K Jerry; Xu, Qin; Zhang, Pengfei; Copeland, Jeffrey H.; Sun, Jenny

    2007-03-06

    The objective of this study is to determine the feasibility that routinely collected data from the Doppler radars can appropriately be used in Atmospheric Dispersion Models (ADMs) for emergency response. We have evaluated the computational efficiency and accuracy of two variational mathematical techniques that derive the u- and v-components of the wind from radial velocities obtained from Doppler radars. A review of the scientific literature indicated that the techniques employ significantly different approaches in applying the variational techniques: 2-D Variational (2DVar), developed by NOAA¹s (National Oceanic and Atmospheric Administration's) National Severe Storms Laboratory (NSSL) and Variational Doppler Radar Analysis System (VDRAS), developed by the National Center for Atmospheric Research (NCAR). We designed a series of numerical experiments in which both models employed the same horizontal domain and resolution encompassing Oklahoma City for a two-week period during the summer of 2003 so that the computed wind retrievals could be fairly compared. Both models ran faster than real-time on a typical single dual-processor computer, indicating that they could be used to generate wind retrievals in near real-time. 2DVar executed ~2.5 times faster than VDRAS because of its simpler approach.

  14. Validation Study of Wave Breaking Influence in a Coupled Wave Model for Hurricane Wind Conditions

    Science.gov (United States)

    2008-08-27

    ACRONYM(S) Grant Management Organisation, The University of New South Wales, Sydney 2052, GMO Australia 11. SPONSOR/MONITOR’S REPORT NUMBER(S) None 12...4.6 Benefit analysis summary 4.6.1 Technical output 4.6.2 Strategic implications Acknowledgements 29 REFERENCES 30 APPENDIX: Details of the wind input...only does this provide a tighter constraint on the form of the spectral dissipation rate source term, but it has the additional benefit of reducing the

  15. Analyzing Hurricane Sandy

    Science.gov (United States)

    Convertino, Angelyn; Meyer, Stephan; Edwards, Becca

    2015-03-01

    Post-tropical Storm Sandy underwent extratropical transition shortly before making landfall in southern New Jersey October 29 2012. Data from this system was compared with data from Hurricane Ike (2008) which represents a classic hurricane with a clear eye wall and symmetry after landfall. Storm Sandy collided with a low pressure system coming in from the north as the hurricane made landfall on the US East coast. This contributed to Storm Sandy acting as a non-typical hurricane when it made landfall. Time histories of wind speed and wind direction were generated from data provided by Texas Tech's StickNet probes for both storms. The NOAA Weather and Climate program were used to generate radar loops of reflectivity during the landfall for both storms; these loops were compared with time histories for both Ike and Sandy to identify a relationship between time series data and storm-scale features identified on radar.

  16. Unified Program for the Specification of Hurricane Boundary Layer Winds Over Surfaces of Specified Roughness.

    Science.gov (United States)

    1992-09-01

    commercial products. rFnn APWn.,W REPORT DOCUMENTATION PAGE oJ_ NO_ o____ PUNK GOPo m=for ta.meuarnca €4 rwmton It "s to "Wuqe I a"oW a•. ama, Wmusma e tune...the mesh size and K is a non-dimensional constant (K = .4 is assumed). The drag coefficient was assumed to increase linearly with wind speed CD a (0.5...system; if the mesh size of the innermost nest is say 5 kln, the second through fifth mesh sizes are 10 , 20 , 40 , and 80 km respectively, and the

  17. Air and water trade winds, hurricanes, gulf stream, tsunamis and other striking phenomena

    CERN Document Server

    Moreau, René

    2017-01-01

    Air and water are so familiar that we all think we know them. Yet how difficult it remains to predict their behavior, with so many questions butting against the limits of our knowledge. How are cyclones, tornadoes, thunderstorms, tsunamis or floods generated — sometimes causing devastation and death? What will the weather be tomorrow, next week, next summer? This book brings some answers to these questions with a strategy of describing before explaining. Starting by considering air and water in equilibrium (i.e., at rest), it progresses to discuss dynamic phenomena first focusing on large scale structures, such as El Niño or trade winds, then on ever smaller structures, such as low-pressure zones in the atmosphere, clouds, rain, as well as tides and waves. It finishes by describing man-mad e constructions (dams, ports, power plants, etc.) that serve to domesticate our water resources and put them to work for us.  Including over one hundred illustrations and very few equations, most of the�...

  18. Generic Hurricane Extreme Seas State

    DEFF Research Database (Denmark)

    Wehmeyer, Christof; Skourup, Jesper; Frigaard, Peter

    2012-01-01

    Extreme sea states, which the IEC 61400-3 (2008) standard requires for the ultimate limit state (ULS) analysis of offshore wind turbines are derived to establish the design basis for the conceptual layout of deep water floating offshore wind turbine foundations in hurricane affected areas...... data is required for a type specific conceptual design. ULS conditions for different return periods are developed, which can subsequently be applied in siteindependent analysis and conceptual design. Recordings provided by National Oceanic and Atmospheric Administration (NOAA), of hurricanes along...... for hurricane generates seas by Young (1998, 2003, and 2006), requiring maximum wind speeds, forward velocity and radius to maximum wind speed. An averaged radius to maximum sustained wind speeds, according to Hsu et al. (1998) and averaged forward speed of cyclonic storms are applied in the initial state...

  19. The VolturnUS 1:8 Floating Wind Turbine: Design, Construction, Deployment, Testing, Retrieval, and Inspection of the First Grid-Connected Offshore Wind Turbine in US

    Energy Technology Data Exchange (ETDEWEB)

    Dagher, Habib [Univ. of Maine, Orono, ME (United States); Viselli, Anthony [Univ. of Maine, Orono, ME (United States); Goupee, Andrew [Univ. of Maine, Orono, ME (United States); Kimball, Richard [Maine Maritime Academy, Castine, ME (United States); Allen, Christopher [Univ. of Maine, Orono, ME (United States)

    2017-08-15

    Volume II of the Final Report for the DeepCwind Consortium National Research Program funded by US Department of Energy Award Number: DE-EE0003278.001 summarizes the design, construction, deployment, testing, numerical model validation, retrieval, and post-deployment inspection of the VolturnUS 1:8-scale floating wind turbine prototype deployed off Castine, Maine on June 2nd, 2013. The 1:8 scale VolturnUS design served as a de-risking exercise for a commercial multi-MW VolturnUS design. The American Bureau of Shipping Guide for Building and Classing Floating Offshore Wind Turbine Installations was used to design the prototype. The same analysis methods, design methods, construction techniques, deployment methods, mooring, and anchoring planned for full-scale were used. A commercial 20kW grid-connected turbine was used and was the first offshore wind turbine in the US.

  20. Hurricane intensification along United States coast suppressed during active hurricane periods.

    Science.gov (United States)

    Kossin, James P

    2017-01-19

    The North Atlantic ocean/atmosphere environment exhibits pronounced interdecadal variability that is known to strongly modulate Atlantic hurricane activity. Variability in sea surface temperature (SST) is correlated with hurricane variability through its relationship with the genesis and thermodynamic potential intensity of hurricanes. Another key factor that governs the genesis and intensity of hurricanes is ambient environmental vertical wind shear (VWS). Warmer SSTs generally correlate with more frequent genesis and greater potential intensity, while VWS inhibits genesis and prevents any hurricanes that do form from reaching their potential intensity. When averaged over the main hurricane-development region in the Atlantic, SST and VWS co-vary inversely, so that the two factors act in concert to either enhance or inhibit basin-wide hurricane activity. Here I show, however, that conditions conducive to greater basin-wide Atlantic hurricane activity occur together with conditions for more probable weakening of hurricanes near the United States coast. Thus, the VWS and SST form a protective barrier along the United States coast during periods of heightened basin-wide hurricane activity. Conversely, during the most-recent period of basin-wide quiescence, hurricanes (and particularly major hurricanes) near the United States coast, although substantially less frequent, exhibited much greater variability in their rate of intensification, and were much more likely to intensify rapidly. Such heightened variability poses greater challenges to operational forecasting and, consequently, greater coastal risk during hurricane events.

  1. Hurricane intensification along United States coast suppressed during active hurricane periods

    Science.gov (United States)

    Kossin, James P.

    2017-01-01

    The North Atlantic ocean/atmosphere environment exhibits pronounced interdecadal variability that is known to strongly modulate Atlantic hurricane activity. Variability in sea surface temperature (SST) is correlated with hurricane variability through its relationship with the genesis and thermodynamic potential intensity of hurricanes. Another key factor that governs the genesis and intensity of hurricanes is ambient environmental vertical wind shear (VWS). Warmer SSTs generally correlate with more frequent genesis and greater potential intensity, while VWS inhibits genesis and prevents any hurricanes that do form from reaching their potential intensity. When averaged over the main hurricane-development region in the Atlantic, SST and VWS co-vary inversely, so that the two factors act in concert to either enhance or inhibit basin-wide hurricane activity. Here I show, however, that conditions conducive to greater basin-wide Atlantic hurricane activity occur together with conditions for more probable weakening of hurricanes near the United States coast. Thus, the VWS and SST form a protective barrier along the United States coast during periods of heightened basin-wide hurricane activity. Conversely, during the most-recent period of basin-wide quiescence, hurricanes (and particularly major hurricanes) near the United States coast, although substantially less frequent, exhibited much greater variability in their rate of intensification, and were much more likely to intensify rapidly. Such heightened variability poses greater challenges to operational forecasting and, consequently, greater coastal risk during hurricane events.

  2. Using Surface Pressure to Improve Tropical Cyclone Surface Wind Retrievals from Synthetic Aperture Radar Imagery

    Science.gov (United States)

    2012-09-30

    Jochen Horstmann of NATO Undersea Research Centre ( NURC ). GD and NURC have developed separate methods for estimating wind directions. In addition, NURC ...has been developing “cross-pol” GMFs, which have a lot of promise in the high wind regime. The GD and NURC wind directions are merged into a single

  3. Influence of the tilting reflection mirror on the temperature and wind velocity retrieved by a polarizing atmospheric Michelson interferometer.

    Science.gov (United States)

    Zhang, Chunmin; Li, Ying

    2012-09-20

    The principles of a polarizing atmospheric Michelson interferometer are outlined. The tilt of its reflection mirror results in deflection of the reflected beam and affects the intensities of the observed inteferogram. This effect is systematically analyzed. Both rectangular and circular apertures are considered. The theoretical expression of the modulation depth and phase of the interferogram are derived. These parameters vary with the inclination angle of the mirror and the distance between the deflection center and the optical axis and significantly influence the retrieved temperature and wind speed. If the wind and temperature errors are required to be less than 3 m/s and 5 K, the deflection angle must be less than 0.5°. The errors are also dependent on the shape of aperture. If the reflection mirror is deflected in one direction, the temperature error is smaller for a circular aperture (1.3 K) than for a rectangular one (2.6 K), but the wind velocity errors are almost the same (less than 3 m/s). If the deflection center and incident light beam are coincident, the temperature errors are 3 × 10(-4) K and 0.45 K for circular and rectangular apertures, respectively. The wind velocity errors are 1.2 × 10(-3) m/s and 0.06 m/s. Both are small. The result would be helpful for theoretical research and development of the static polarization wind imaging interferometer.

  4. Satellite sar detection of hurricane helene (2006)

    DEFF Research Database (Denmark)

    Ju, Lian; Cheng, Yongcun; Xu, Qing;

    2013-01-01

    In this paper, the wind structure of hurricane Helene (2006) over the Atlantic Ocean is investigated from a C-band RADARSAT-1 synthetic aperture radar (SAR) image acquired on 20 September 2006. First, the characteristics, e.g., the center, scale and area of the hurricane eye (HE) are determined...

  5. Extreme Velocity Wind Sensor

    Science.gov (United States)

    Perotti, Jose; Voska, Ned (Technical Monitor)

    2002-01-01

    This presentation provides an overview of the development of new hurricane wind sensor (Extreme Velocity Wind Sensor) for the Kennedy Space Center (KSC) which is designed to withstand winds of up to three hundred miles an hour. The proposed Extreme Velocity Wind Sensor contains no moveable components that would be exposed to extreme wind conditions. Topics covered include: need for new hurricane wind sensor, conceptual design, software applications, computational fluid dynamic simulations of design concept, preliminary performance tests, and project status.

  6. Hurricane Season

    Institute of Scientific and Technical Information of China (English)

    JENNIFER; JETT

    2008-01-01

    Three years after Katrina,the United States isdetermined not to repeatits mistakes This year has seen an unusually activeand deadly hurricane season, asstorms line up in the Atlantic Oceanto pummel the Caribbean and UnitedStates coastline.

  7. Hurricane Matthew Takes Aim At Florida

    Science.gov (United States)

    ... plan for adequate supplies in case you lose power and water for several days and you are not able to leave due to flooding or blocked roads. Hurricane winds can cause trees and branches to fall, so trim or remove ...

  8. Hurricane Force Winds in Explosive Maritime Extratropical Cyclones: A Modeling and Observational Study of Their Evolution and Dynamics

    Science.gov (United States)

    Albright, Benjamin Scott

    Extratropical cyclones can be as powerful as tropical cyclones with winds reaching 33 m s-1 or even stronger. They can also be very large in scale, and impact life and property on the oceans as well as over the land if the storms make a landfall. Two conceptual models exist that attempt to explain how the extreme winds in the bent-back frontal zone of these cyclones occur. The first is a jet associated with the cold conveyor belt and the second is through a phenomenon known as a sting jet. Some of the objectives this thesis will address are: (1) The role of gradient wind is during the life-cycle of the cyclone, (2) how model results compare to actual observations, and (3) if the sting jet or cold conveyor belt jet are the only causes for high winds within the bent-back frontal zone, among others. This thesis will examine two case studies of extreme, extratropical cyclones that occurred over the North Atlantic Ocean. Extensive observations including dropsondes, Stepped Frequency Microwave Radiometer (SFMR) measurements from a NOAA WP-3D aircraft and satellite scatterometer measurements are used to compare with modeled results of the two case studies. The Weather Research and Forecasting (WRF) Model Version 3.4.1 and the NOAA Environmental Modeling System (NEMS) NMM-B Launcher are used to model the two case studies and for high resolution and sensitivity testing. Trajectories calculated by the Read/Interpolate/Plot program and cross sections are additional tools used in the study. Some of the major conclusions included identifying sting jets in each storm but they were found not to be the major cause of the highest winds within the bent-back frontal zone. A secondary stream of air that accelerates from the west of the rapidly intensifying cyclone into a low-level jet located within a larger pressure gradient force and thermal gradient was found to be the major source of the high winds. It is suggested that the findings and conclusions based on the results of this

  9. 4-D-VAR assimilation of disdrometer data and radar spectral reflectivities for raindrop size distribution and vertical wind retrievals

    Science.gov (United States)

    Mercier, François; Chazottes, Aymeric; Barthès, Laurent; Mallet, Cécile

    2016-07-01

    This paper presents a novel framework for retrieving the vertical raindrop size distribution (DSD) and vertical wind profiles during light rain events. This is also intended as a tool to better characterize rainfall microphysical processes. It consists in coupling K band Doppler spectra and ground disdrometer measurements (raindrop fluxes) in a 2-D numerical model propagating the DSD from the clouds to the ground level. The coupling is done via a 4-D-VAR data assimilation algorithm. As a first step, in this paper, the dynamical model and the geometry of the problem are quite simple. They do not allow the complexity implied by all rain microphysical processes to be encompassed (evaporation, coalescence breakup and horizontal air motion are not taken into account). In the end, the model is limited to the fall of droplets under gravity, modulated by the effects of vertical winds. The framework is thus illustrated with light, stratiform rain events. We firstly use simulated data sets (data assimilation twin experiment) to show that the algorithm is able to retrieve the DSD profiles and vertical winds. It also demonstrates the ability of the algorithm to deal with the atmospheric turbulence (broadening of the Doppler spectra) and the instrumental noise. The method is then applied to a real case study which was conducted in the southwest of France during the autumn 2013. The data set collected during a long, quiet event (6 h duration, rain rate between 2 and 7 mm h-1) comes from an optical disdrometer and a 24 GHz vertically pointing Doppler radar. We show that the algorithm is able to reproduce the observations and retrieve realistic DSD and vertical wind profiles, when compared to what could be expected for such a rain event. A goal for this study is to apply it to extended data sets for a validation with independent data, which could not be done with our limited 2013 data. Other data sets would also help to parameterize more processes needed in the model (evaporation

  10. Gulf of Mexico hurricane wave simulations using SWAN: Bulk formula-based drag coefficient sensitivity for Hurricane Ike

    NARCIS (Netherlands)

    Huang, Y.; Weisberg, R.H.; Zheng, L.; Zijlema, M.

    2013-01-01

    The effects of wind input parameterizations on wave estimations under hurricane conditions are examined using the unstructured grid, third-generation wave model, Simulating WAves Nearshore (SWAN). Experiments using Hurricane Ike wind forcing, which impacted the Gulf of Mexico in 2008, illustrate tha

  11. Gulf of Mexico hurricane wave simulations using SWAN: Bulk formula-based drag coefficient sensitivity for Hurricane Ike

    NARCIS (Netherlands)

    Huang, Y.; Weisberg, R.H.; Zheng, L.; Zijlema, M.

    2013-01-01

    The effects of wind input parameterizations on wave estimations under hurricane conditions are examined using the unstructured grid, third-generation wave model, Simulating WAves Nearshore (SWAN). Experiments using Hurricane Ike wind forcing, which impacted the Gulf of Mexico in 2008, illustrate tha

  12. Gulf of Mexico hurricane wave simulations using SWAN: Bulk formula-based drag coefficient sensitivity for Hurricane Ike

    NARCIS (Netherlands)

    Huang, Y.; Weisberg, R.H.; Zheng, L.; Zijlema, M.

    2013-01-01

    The effects of wind input parameterizations on wave estimations under hurricane conditions are examined using the unstructured grid, third-generation wave model, Simulating WAves Nearshore (SWAN). Experiments using Hurricane Ike wind forcing, which impacted the Gulf of Mexico in 2008, illustrate

  13. Female hurricanes are deadlier than male hurricanes.

    Science.gov (United States)

    Jung, Kiju; Shavitt, Sharon; Viswanathan, Madhu; Hilbe, Joseph M

    2014-06-17

    Do people judge hurricane risks in the context of gender-based expectations? We use more than six decades of death rates from US hurricanes to show that feminine-named hurricanes cause significantly more deaths than do masculine-named hurricanes. Laboratory experiments indicate that this is because hurricane names lead to gender-based expectations about severity and this, in turn, guides respondents' preparedness to take protective action. This finding indicates an unfortunate and unintended consequence of the gendered naming of hurricanes, with important implications for policymakers, media practitioners, and the general public concerning hurricane communication and preparedness.

  14. WIND DAMAGE ON TREES FOLLOWING HURRICANE SANDY AND IMPLICATIONS FOR CITY LANDSCAPING: GLEN RIDGE – MONTCLAIR TOWNS, NEW JERSEY

    Directory of Open Access Journals (Sweden)

    FAITH JUSTUS

    2013-05-01

    Full Text Available Glen Ridge is a small municipality in the Northern New Jersey with a significant number of huge trees lining majority of its streets. The trees have been subject to a wide range of natural and artificial stresses, one being the strong wind associated with superstorm Sandy. On 29th October 2012, a windstorm of extreme intensity struck the Tristate region and brought havoc to the tree population including those in Glen Ridge. A survey was conducted immediately after the storm to collect quantitative information on fallen tree population. The study aimed at understanding the spatial extent of wind damage on trees with reference to location, trunk diameter and soil characteristics. A total of 51 fallen trees with a mean trunk diameter of 100.4 centimetres along streets in study area were surveyed. High damage was noted on trees in Glen Ridge (29 trees while streets transitioning to Montclair had 22 fallen trees. Majority of the surveyed trees were found on USBOO soils (49%, which are characterised as disturbed urban soils with Boonton substratum-Boonton complexes. BowrB soils had 27.5%, Boob 13.7%, BowrC 7.8% and USDUNB 2.0% of fallen trees. A need for city wide tree inventorying and species mapping is identified as a management implication to further enhance the historical value of the city. Other measures are discussed with a view of engaging appropriate local management partnerships and coordination frameworks to play a role in protecting the remaining large trees.

  15. Simulation of hurricane response to suppression of warm rain by sub-micron aerosols

    National Research Council Canada - National Science Library

    Rosenfeld, D; Khain, A; Lynn, B; Woodley, W. L

    2007-01-01

    ...). The possible impact of seeding of clouds with submicron cloud condensation nuclei (CCN) on hurricane structure and intensity as measured by nearly halving of the area covered by hurricane force winds was simulated by "turning...

  16. Hurricane Charley Exposure and Hazard of Preterm Delivery, Florida 2004.

    Science.gov (United States)

    Grabich, Shannon C; Robinson, Whitney R; Engel, Stephanie M; Konrad, Charles E; Richardson, David B; Horney, Jennifer A

    2016-12-01

    Objective Hurricanes are powerful tropical storm systems with high winds which influence many health effects. Few studies have examined whether hurricane exposure is associated with preterm delivery. We aimed to estimate associations between maternal hurricane exposure and hazard of preterm delivery. Methods We used data on 342,942 singleton births from Florida Vital Statistics Records 2004-2005 to capture pregnancies at risk of delivery during the 2004 hurricane season. Maternal exposure to Hurricane Charley was assigned based on maximum wind speed in maternal county of residence. We estimated hazards of overall preterm delivery (<37 gestational weeks) and extremely preterm delivery (<32 gestational weeks) in Cox regression models, adjusting for maternal/pregnancy characteristics. To evaluate heterogeneity among racial/ethnic subgroups, we performed analyses stratified by race/ethnicity. Additional models investigated whether exposure to multiples hurricanes increased hazard relative to exposure to one hurricane. Results Exposure to wind speeds ≥39 mph from Hurricane Charley was associated with a 9 % (95 % CI 3, 16 %) increase in hazard of extremely preterm delivery, while exposure to wind speed ≥74 mph was associated with a 21 % (95 % CI 6, 38 %) increase. Associations appeared greater for Hispanic mothers compared to non-Hispanic white mothers. Hurricane exposure did not appear to be associated with hazard of overall preterm delivery. Exposure to multiple hurricanes did not appear more harmful than exposure to a single hurricane. Conclusions Hurricane exposure may increase hazard of extremely preterm delivery. As US coastal populations and hurricane severity increase, the associations between hurricane and preterm delivery should be further studied.

  17. Retrieving wind statistics from average spectrum of continuous-wave lidar

    DEFF Research Database (Denmark)

    Branlard, Emmanuel; Pedersen, Anders Tegtmeier; Mann, Jakob

    2013-01-01

    -order atmospheric turbulence statistics. An atmospheric field campaign and a wind tunnel experiment are carried out to show that the use of an average Doppler spectrum instead of a time series of velocities determined from individual Doppler spectra significantly reduces the differences with the standard deviation...... measured using ordinary anemometers, such as ultra-sonic anemometers or hotwires. The proposed method essentially removes the spatial averaging effect intrinsic to the cw lidar systems....

  18. Comparisons of Wind Speed Retrievals from an Airborne Microwave Radiometer (AMPR) with Satellite-Based Observations During the OLYMPEX/RADEX Field Campaign

    Science.gov (United States)

    Lang, Timothy J.; Biswas, Sayak

    2017-01-01

    AMPR is an airborne instrument that flew aboard the NASA ER-2 during the OLYMPEX/RADEX field campaign in late 2015. This poster's goal is to explore how well the instrument can retrieve near-surface wind speed over the ocean.

  19. Hurricane Resource Reel

    Data.gov (United States)

    National Aeronautics and Space Administration — This Reel Includes the Following Sections TRT 50:10 Hurricane Overviews 1:02; Hurricane Arthur 15:07; Cyclone Pam 19:48; Typhoon Hagupit 21:27; Hurricane Bertha...

  20. Hurricane Evacuation Routes

    Data.gov (United States)

    Department of Homeland Security — Hurricane Evacuation Routes in the United States A hurricane evacuation route is a designated route used to direct traffic inland in case of a hurricane threat. This...

  1. Retrieval of convective boundary layer wind field statistics from radar profiler measurements in conjunction with large eddy simulation

    Directory of Open Access Journals (Sweden)

    Danny Scipión

    2009-05-01

    Full Text Available The daytime convective boundary layer (CBL is characterized by strong turbulence that is primarily forced by buoyancy transport from the heated underlying surface. The present study focuses on an example of flow structure of the CBL as observed in the U.S. Great Plains on June 8, 2007. The considered CBL flow has been reproduced using a numerical large eddy simulation (LES, sampled with an LES-based virtual boundary layer radar (BLR, and probed with an actual operational radar profiler. The LES-generated CBL flow data are then ingested by the virtual BLR and treated as a proxy for prevailing atmospheric conditions. The mean flow and turbulence parameters retrieved via each technique (actual radar profiler, virtual BLR, and LES have been cross-analyzed and reasonable agreement was found between the CBL wind parameters obtained from the LES and those measured by the actual radar. Averaged vertical velocity variance estimates from the virtual and actual BLRs were compared with estimates calculated from the LES for different periods of time. There is good agreement in the estimates from all three sources. Also, values of the vertical velocity skewness retrieved by all three techniques have been inter-compared as a function of height for different stages of the CBL evolution, showing fair agreement with each other. All three retrievals contain positively skewed vertical velocity structure throughout the main portion of the CBL. Radar estimates of the turbulence kinetic energy (eddy dissipation rate (ε have been obtained based on the Doppler spectral width of the returned signal for the vertical radar beam. The radar estimates were averaged over time in the same fashion as the LES output data. The agreement between estimates was generally good, especially within the mixing layer. Discrepancies observed above the inversion layer may be explained by a weak turbulence signal in particular flow configurations. The virtual BLR produces voltage

  2. Numerical Research on Effects Upon Precipitation Forecast of Doppler-Radar Estimated Precipitation and Retrieved Wind Field Under Different Model Initial Schemes

    Institute of Scientific and Technical Information of China (English)

    WANG Yehong; ZHAO Yuchun; CUI Chunguang

    2007-01-01

    On the basis of the joint estimated 1-h precipitation from Changde, Jingzhou, and Yichang Doppler radars as well as Wuhan digital radar, and the retrieved wind fields from Yichang and Jingzhou Doppler radars, a series of numerical experiments with an advanced regional η-coordinate model (AREM) under different model initial schemes, i.e., Grapes-3DVAR, Barnes objective analysis, and Barnes-3DVAR, are carried out for a torrential rain process occurring along the Yangtze River in the 24-h period from 2000 BT 22 July 2002 to investigate the effects of the Doppler-radar estimated rainfall and retrieved winds on the rainfall forecast. The main results are as follows: (1) The simulations are obviously different under three initial schemes with the same data source (the radiosounding and T213L31 analysis). On the whole,Barnes-3DVAR, which combines the advantages of the Barnes objective analysis and the Grapes-3DVAR method, gives the best simulations: well-simulated rain band and clear mesoscale structures, as well as their location and intensity close to observations. (2) Both Barnes-3DVAR and Grapes-3DVAR schemes are able to assimilate the Doppler-radar estimated rainfall and retrieved winds, but differences in simulation results are very large, with Barnes-3DVAR's simulation much better than Grapes-3DVAR's. (3) Under Grapes3DVAR scheme, the simulation of 24-h rainfall is improved obviously when assimilating the Doppler-radar estimated precipitation into the model in compared with the control experiment; but it becomes a little worse when assimilating the Doppler-radar retrieved winds into the model, and it becomes worse obviously when assimilating the Doppler-radar estimated precipitation as well as retrieved winds into the model. However,the simulation is different under Barnes-3DVAR scheme. The simulation is improved to a certain degree no matter assimilating the estimated precipitation or retrieved winds, or both of them. The result is the best when assimilating both

  3. Stratospheric temperature measurement with scanning Fabry-Perot interferometer for wind retrieval from mobile Rayleigh Doppler lidar.

    Science.gov (United States)

    Xia, Haiyun; Dou, Xiankang; Shangguan, Mingjia; Zhao, Ruocan; Sun, Dongsong; Wang, Chong; Qiu, Jiawei; Shu, Zhifeng; Xue, Xianghui; Han, Yuli; Han, Yan

    2014-09-08

    Temperature detection remains challenging in the low stratosphere, where the Rayleigh integration lidar is perturbed by aerosol contamination and ozone absorption while the rotational Raman lidar is suffered from its low scattering cross section. To correct the impacts of temperature on the Rayleigh Doppler lidar, a high spectral resolution lidar (HSRL) based on cavity scanning Fabry-Perot Interferometer (FPI) is developed. By considering the effect of the laser spectral width, Doppler broadening of the molecular backscatter, divergence of the light beam and mirror defects of the FPI, a well-behaved transmission function is proved to show the principle of HSRL in detail. Analysis of the statistical error of the HSRL is carried out in the data processing. A temperature lidar using both HSRL and Rayleigh integration techniques is incorporated into the Rayleigh Doppler wind lidar. Simultaneous wind and temperature detection is carried out based on the combined system at Delhi (37.371°N, 97.374°E; 2850 m above the sea level) in Qinghai province, China. Lower Stratosphere temperature has been measured using HSRL between 18 and 50 km with temporal resolution of 2000 seconds. The statistical error of the derived temperatures is between 0.2 and 9.2 K. The temperature profile retrieved from the HSRL and wind profile from the Rayleigh Doppler lidar show good agreement with the radiosonde data. Specifically, the max temperature deviation between the HSRL and radiosonde is 4.7 K from 18 km to 36 km, and it is 2.7 K between the HSRL and Rayleigh integration lidar from 27 km to 34 km.

  4. Design Considerations for a Dual-Frequency Radar for Sea Spray Measurement in Hurricanes

    Science.gov (United States)

    Esteban-Fernandez, Daniel; Durden, Stephen L.; Chaubell, Julian; Cooper, Kenneth B.

    2010-01-01

    Over the last few years, researchers have determined that sea spray from breaking waves can have a large effect on the magnitude and distribution of the air-sea energy flux at hurricane-force wind speeds. Characterizing the fluxes requires estimates of the height-dependent droplet size distribution (DSD). Currently, the few available measurements have been acquired with spectrometer probes, which can provide only flight-level measurements. As such, in-situ measurement of near-surface droplet fluxes in hurricanes with these instruments is, at best, extremely challenging, if at all possible. This paper describes an airborne dual-wavelength radar profiler concept to retrieve the DSD of sea spray.

  5. Retrieving wind statistics from average spectrum of continuous-wave lidar

    Directory of Open Access Journals (Sweden)

    E. Branlard

    2013-07-01

    Full Text Available The aim of this study is to experimentally demonstrate that the time-average Doppler spectrum of a continuous-wave (cw lidar is proportional to the probability density function of the line-of-sight velocities. This would open the possibility of using cw lidars for the determination of the second-order atmospheric turbulence statistics. An atmospheric field campaign and a wind tunnel experiment are carried out to show that the use of an average Doppler spectrum instead of a time series of velocities determined from individual Doppler spectra significantly reduces the differences with the standard deviation measured using ordinary anemometers, such as ultra-sonic anemometers or hotwires. The proposed method essentially removes the spatial averaging effect intrinsic to the cw lidar systems.

  6. Drag Coefficient and Foam in Hurricane Conditions.

    Science.gov (United States)

    Golbraikh, E.; Shtemler, Y.

    2016-12-01

    he present study is motivated by recent findings of saturation and even decrease in the drag coefficient (capping) in hurricane conditions, which is accompanied by the production of a foam layer on the ocean surface. As it is difficult to expect at present a comprehensive numerical modeling of the drag coefficient saturation that is followed by wave breaking and foam production, there is no complete confidence and understanding of the saturation phenomenon. Our semi-empirical model is proposed for the estimation of the foam impact on the variation of the effective drag coefficient, Cd , with the reference wind speed U10 in stormy and hurricane conditions. The proposed model treats the efficient air-sea aerodynamic roughness length as a sum of two weighted aerodynamic roughness lengths for the foam-free and foam-covered conditions. On the available optical and radiometric measurements of the fractional foam coverage,αf, combined with direct wind speed measurements in hurricane conditions, which provide the minimum of the effective drag coefficient, Cd for the sea covered with foam. The present model yields Cd10 versus U10 in fair agreement with that evaluated from both open-ocean and laboratory measurements of the vertical variation of mean wind speed in the range of U10 from low to hurricane speeds. The present approach opens opportunities for drag coefficient modeling in hurricane conditions and hurricane intensity estimation by the foam-coverage value using optical and radiometric measurements.

  7. WISE 2000 campaign: sea surface salinity and wind retrievals from L-band radiometry

    Science.gov (United States)

    Camps, Adriano; Corbella, Ignasi; Font, Jordi; Etchetto, Jacqueline; Duffo, Nuria; Vall-llossera, Merce; Bara, Javier; Torres, Francisco; Wursteisen, Patrick; Martin-Neira, Manuel

    2000-12-01

    Sea surface salinity (SSS) has been recognized as a key parameter in climatological studies. SSS can be measured by passive microwave remote sensing at L band, where the sensitivity of the brightness temperatures shows a maximum and the atmosphere is almost transparent. To provide global coverage of this basic parameter with a 3-day revisit time, the SMOS mission was recently selected by ESA within the frame of the Earth Explorer Opportunity Missions. The SMOS mission will carry the MIRAS instrument, the first 2D L-band aperture synthesis interferometric radiometer. To address new challenges that this mission presents, such as incidence angle variation with pixel, polarization mixing, effect of wind and foam and others, a measurement campaign has been sponsored by ESA under the name of WISE 2000 and it is scheduled for October-November 2000. Two L-band radiometers, a video, a IR and a stereo-camera and four oceanographic and meteorological buoys will be installed in the oil platform 'Casablanca' located at 40 Km off the coast of Tarragona, where the sea conditions are representative of the Mediterranean open sea with periodic influence of the Ebro river fresh water plume.

  8. Santa Ana Winds Over Los Angeles

    Science.gov (United States)

    2003-01-01

    High-resolution ocean surface wind data from NASA's Quick Scatterometer (QuikScat) illustrate the strength of Santa Ana winds that pounded Southern California this week, causing damage and spreading brush fires. The colored arrows represent various ranges of wind speed, which were still well in excess of 30 knots (34 miles per hour), even after reaching the ocean and weakening. Santa Ana winds are offshore and down-slope winds unique to Southern California that are usually channeled through mountain gaps. These Santa Ana winds extend more than 500 kilometers (310 miles) offshore before changing direction to flow along the shore.The wind speeds and directions are retrieved from range-compressed backscatter data measured by QuikScat that has much higher spatial resolution than QuikScat's standard data products. Useful applications of high-resolution science-quality wind products derived from range-compressed backscatter have been demonstrated in two scientific papers: one on Hurricane Floyd and the other on Catalina Eddies. This is the first demonstration on near-real-time retrieval applications.

  9. Sea Surface Salinity and Wind Retrieval Algorithm Using Combined Passive-Active L-Band Microwave Data

    Science.gov (United States)

    Yueh, Simon H.; Chaubell, Mario J.

    2011-01-01

    Aquarius is a combined passive/active L-band microwave instrument developed to map the salinity field at the surface of the ocean from space. The data will support studies of the coupling between ocean circulation, the global water cycle, and climate. The primary science objective of this mission is to monitor the seasonal and interannual variation of the large scale features of the surface salinity field in the open ocean with a spatial resolution of 150 kilometers and a retrieval accuracy of 0.2 practical salinity units globally on a monthly basis. The measurement principle is based on the response of the L-band (1.413 gigahertz) sea surface brightness temperatures (T (sub B)) to sea surface salinity. To achieve the required 0.2 practical salinity units accuracy, the impact of sea surface roughness (e.g. wind-generated ripples and waves) along with several factors on the observed brightness temperature has to be corrected to better than a few tenths of a degree Kelvin. To the end, Aquarius includes a scatterometer to help correct for this surface roughness effect.

  10. Physical aspects of Hurricane Hugo in Puerto Rico

    Science.gov (United States)

    Scatena, F.N.; Larsen, Matthew C.

    1991-01-01

    On 18 September 1989 the western part ofHurricane Hugo crossed eastern Puerto Rico and the Luquillo Experimental Forest (LEF). Storm-facing slopes on the northeastern part of the island that were within 15 km of the eye and received greater than 200 mm of rain were most affected by the storm. In the LEF and nearby area, recurrence intervals associated with Hurricane Hugo were 50 yr for wind velocity, 10 to 31 yr for stream discharge, and 5 yr for rainfall intensity. To compare the magnitudes of the six hurricanes to pass over PuertoRico since 1899, 3 indices were developed using the standardized values of the product of: the maximum sustained wind speed at San Juan squared and storm duration; the square of the product of the maximum sustained wind velocity at San Juan and the ratio of the distance between the hurricane eye and San Juan to the distance between the eye and percentage of average annual rainfall delivered by the storm. Based on these indices, HurricaneHugo was of moderate intensity. However, because of the path of Hurricane Hugo, only one of these six storms (the 1932 storm) caused more damage to the LEF than Hurricane Hugo. Hurricanes of Hugo's magnitude are estimated to pass over the LEF once every 50-60 yr, on average. 

  11. 2005 Atlantic Hurricanes Poster

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 2005 Atlantic Hurricanes poster features high quality satellite images of 15 hurricanes which formed in the Atlantic Basin (includes Gulf of Mexico and Caribbean...

  12. Hurricane Gustav Poster

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hurricane Gustav poster. Multi-spectral image from NOAA-17 shows Hurricane Gustav having made landfall along the Louisiana coastline. Poster size is 36"x27"

  13. Hurricane Ike Poster

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hurricane Ike poster. Multi-spectral image from NOAA-15 shows Hurricane Ike in the Gulf of Mexico heading toward Galveston Island, Texas. Poster size is 36"x27".

  14. 2004 Landfalling Hurricanes Poster

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 2004 U.S. Landfalling Hurricanes poster is a special edition poster which contains two sets of images of Hurricanes Charley, Frances, Ivan, and Jeanne, created...

  15. A Coordinated USGS Science Response to Hurricane Sandy

    Science.gov (United States)

    Jones, S.; Buxton, H. T.; Andersen, M.; Dean, T.; Focazio, M. J.; Haines, J.; Hainly, R. A.

    2013-12-01

    In late October 2012, Hurricane Sandy came ashore during a spring high tide on the New Jersey coastline, delivering hurricane-force winds, storm tides exceeding 19 feet, driving rain, and plummeting temperatures. Hurricane Sandy resulted in 72 direct fatalities in the mid-Atlantic and northeastern United States, and widespread and substantial physical, environmental, ecological, social, and economic impacts estimated at near $50 billion. Before the landfall of Hurricane Sandy, the USGS provided forecasts of potential coastal change; collected oblique aerial photography of pre-storm coastal morphology; deployed storm-surge sensors, rapid-deployment streamgages, wave sensors, and barometric pressure sensors; conducted Light Detection and Ranging (lidar) aerial topographic surveys of coastal areas; and issued a landslide alert for landslide prone areas. During the storm, Tidal Telemetry Networks provided real-time water-level information along the coast. Long-term networks and rapid-deployment real-time streamgages and water-quality monitors tracked river levels and changes in water quality. Immediately after the storm, the USGS serviced real-time instrumentation, retrieved data from over 140 storm-surge sensors, and collected other essential environmental data, including more than 830 high-water marks mapping the extent and elevation of the storm surge. Post-storm lidar surveys documented storm impacts to coastal barriers informing response and recovery and providing a new baseline to assess vulnerability of the reconfigured coast. The USGS Hazard Data Distribution System served storm-related information from many agencies on the Internet on a daily basis. Immediately following Hurricane Sandy the USGS developed a science plan, 'Meeting the Science Needs of the Nation in the Wake of Hurricane Sandy-A U.S. Geological Survey Science Plan for Support of Restoration and Recovery'. The plan will ensure continuing coordination of internal USGS activities as well as

  16. Hurricane Sandy and earthquakes

    OpenAIRE

    MAVASHEV BORIS; MAVASHEV IGOR

    2013-01-01

    Submit for consideration the connection between formation of a hurricane Sandy and earthquakes. As a rule, weather anomalies precede and accompany earthquakes. The hurricane Sandy emerged 2 days prior to strong earthquakes that occurred in the area. And the trajectory of the hurricane Sandy matched the epicenter of the earthquakes. Possibility of early prediction of natural disasters will minimize the moral and material damage.

  17. Rapid mapping of hurricane damage to forests

    Science.gov (United States)

    Erik M. Nielsen

    2009-01-01

    The prospects for producing rapid, accurate delineations of the spatial extent of forest wind damage were evaluated using Hurricane Katrina as a test case. A damage map covering the full spatial extent of Katrina?s impact was produced from Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery using higher resolution training data. Forest damage...

  18. The Hurricane Imaging Radiometer: Present and Future

    Science.gov (United States)

    Miller, Timothy L.; James, M. W.; Roberts, J. B.; Biswas, S. K.; Cecil, D.; Jones, W. L.; Johnson, J.; Farrar, S.; Sahawneh, S.; Ruf, C. S.; Morris, M.; Uhlhorn, E. W.; Black, P. G.

    2013-01-01

    The Hurricane Imaging Radiometer (HIRAD) is an airborne passive microwave radiometer designed to provide high resolution, wide swath imagery of surface wind speed in tropical cyclones from a low profile planar antenna with no mechanical scanning. Wind speed and rain rate images from HIRAD's first field campaign (GRIP, 2010) are presented here followed, by a discussion on the performance of the newly installed thermal control system during the 2012 HS3 campaign. The paper ends with a discussion on the next generation dual polarization HIRAD antenna (already designed) for a future system capable of measuring wind direction as well as wind speed.

  19. Global Tropical Cyclone Winds from the QuikSCAT and OceanSAT-2 Scatterometers

    Science.gov (United States)

    Stiles, B. W.; Danielson, R. E.; Poulsen, W. L.; Fore, A.; Brennan, M. J.; Shen, T. J.; Hristova-Veleva, S. M.

    2012-12-01

    We have produced a comprehensive set of tropical cyclone storm wind retrieval scenes for all ten years of QuikSCAT data and one year of OceanSAT-2 data. The wind speeds were corrected for rain and optimized to avoid saturation at high winds using an artificial neural network method similar to that in [1] and [2]. The QuikSCAT wind imagery and the quantitative speed, direction, and backscatter data can be obtained at http://tropicalcyclone.jpl.nasa.gov. The QuikSCAT wind speeds have been validated against best track intensity (i.e., maximum wind speeds), H*WIND tropical cyclone wind model analysis fields, and wind speeds from aircraft overflights (GPS drop wind sondes and step frequency microwave radiometer (SFMR) wind measurements). Storms from all basins are included for a total of 21600 scenes over the ten years of nominal QuikSCAT operations. Of these, 11435 scenes include the best track center of the cyclone in the retrieved wind field. Among these, 3295 were of tropical storms and 788, 367, 330, 289, and 55 were of category 1, 2, 3, 4 and 5 hurricanes, respectively, on the Saffir-Simpson Hurricane Wind Scale. In addition to the QuikSCAT hurricane winds, we have also processed one year of wind fields from the Indian Space Research organization (ISRO) OceanSAT-2 satellite. OceanSAT-2 employs a scanning pencil beam Ku-band scatterometer with a design similar to QuikSCAT. JPL and NOAA have been working extensively with ISRO to aid in cross calibration between OceanSAT-2 and QuikSCAT. Toward this end the QuikSCAT instrument has been repointed in order to acquire data at the OceanSAT-2 incidence angles, and several meetings in India between the teams have taken place. The neural network that was trained on QuikSCAT data was used to retrieve OceanSAT-2 winds. The backscatter inputs to the network were transformed to match the histograms of the corresponding values in the QuikSCAT data set. We examine the scatterometer winds to investigate the relationship between

  20. Condensation-induced kinematics and dynamics of cyclones, hurricanes and tornadoes

    Science.gov (United States)

    Makarieva, A. M.; Gorshkov, V. G.

    2009-11-01

    A universal equation is obtained for air pressure and wind velocity in cyclones, hurricanes and tornadoes as dependent on the distance from the center of the considered wind pattern driven by water vapor condensation. The obtained theoretical estimates of the horizontal profiles of air pressure and wind velocity, eye and wind wall radius in hurricanes and tornadoes and maximum values of the radial, tangential and vertical velocity components are in good agreement with empirical evidence.

  1. TRMM-retrieved Cloud Structure and Evolution of MCSs over the Northern South China Sea and Impacts of CAPE and Vertical Wind Shear

    Institute of Scientific and Technical Information of China (English)

    LI Xiangshu; GUO Xueliang; FU Danhong

    2013-01-01

    Cloud structure and evolution of Mesoscale Convective Systems (MCSs) retrieved from the Tropical Rainfall Measuring Mission Microwave Imager (TRMM TMI) and Precipitation Radar (PR) were investigated and compared with some pioneer studies based on soundings and models over the northern South China Sea (SCS).The impacts of Convective Available Potential Energy (CAPE) and environmental vertical wind shear on MCSs were also explored.The main features of MCSs over the SCS were captured well by both TRMM PR and TMI.However,the PR-retrieved surface rainfall in May was less than that in June,and the reverse for TMI.TRMM-retrieved rainfall amounts were generally consistent with those estimated from sounding and models.However,rainfall amounts from sounding-based and PR-based estimates were relatively higher than those retrieved from TRMM-TMI data.The Weather Research and Forecasting (WRF) modeling simulation underestimated the maximum rain rate by 22% compared to that derived from TRMM-PR,and underestimated mean rainfall by 10.4% compared to the TRMM-TMI estimate,and by 12.5% compared to the sounding-based estimate.The warm microphysical processes modeled from both the WRF and the Goddard Cumulus Ensemble (GCE) models were quite close to those based on TMI,but the ice water contents in the models were relatively less compared to that derived from TMI.The CAPE and wind shear induced by the monsoon circulation were found to play critical roles in maintaining and developing the intense convective clouds over SCS.The latent heating rate increased more than twofold during the monsoon period and provided favorable conditions for the upward transportation of energy from the ocean,giving rise to the possibility of inducing large-scale interactions.

  2. Using the QBO to predict the number of hurricanes hitting the U.S

    CERN Document Server

    Coughlin, Katie

    2007-01-01

    A simple study of the relationship between the QBO and the number of hurricanes in the Atlantic, both in the Basin and hitting the U.S. coastline, demonstrates that the QBO is not a particularly useful index to help predict hurricane numbers on five-year time scales. It is shown that there is very little difference between the number of hurricanes following easterly winds in the equatorial stratosphere and the number that follow westerly winds. Given this it is reasonable one would make better predictions just using the mean number of hurricanes in lieu of using the QBO and this is also simply demonstrated here.

  3. Two Empirical Models for Land-falling Hurricane Gust Factors

    Science.gov (United States)

    Merceret, Franics J.

    2008-01-01

    Gaussian and lognormal models for gust factors as a function of height and mean windspeed in land-falling hurricanes are presented. The models were empirically derived using data from 2004 hurricanes Frances and Jeanne and independently verified using data from 2005 hurricane Wilma. The data were collected from three wind towers at Kennedy Space Center and Cape Canaveral Air Force Station with instrumentation at multiple levels from 12 to 500 feet above ground level. An additional 200-foot tower was available for the verification. Mean wind speeds from 15 to 60 knots were included in the data. The models provide formulas for the mean and standard deviation of the gust factor given the mean windspeed and height above ground. These statistics may then be used to assess the probability of exceeding a specified peak wind threshold of operational significance given a specified mean wind speed.

  4. Spatial structure of directional wave spectra in hurricanes

    Science.gov (United States)

    Esquivel-Trava, Bernardo; Ocampo-Torres, Francisco J.; Osuna, Pedro

    2015-01-01

    The spatial structure of the wave field during hurricane conditions is studied using the National Data Buoy Center directional wave buoy data set from the Caribbean Sea and the Gulf of Mexico. The buoy information, comprising the directional wave spectra during the passage of several hurricanes, was referenced to the center of the hurricane using the path of the hurricane, the propagation velocity, and the radius of the maximum winds. The directional wave spectra were partitioned into their main components to quantify the energy corresponding to the observed wave systems and to distinguish between wind-sea and swell. The findings are consistent with those found using remote sensing data (e.g., Scanning Radar Altimeter data). Based on the previous work, the highest waves are found in the right forward quadrant of the hurricane, where the spectral shape tends to become uni-modal, in the vicinity of the region of maximum winds. More complex spectral shapes are observed in distant regions at the front of and in the rear quadrants of the hurricane, where there is a tendency of the spectra to become bi- and tri-modal. The dominant waves generally propagate at significant angles to the wind direction, except in the regions next to the maximum winds of the right quadrants. Evidence of waves generated by concentric eyewalls associated with secondary maximum winds was also found. The frequency spectra display some of the characteristics of the JONSWAP spectrum adjusted by Young (J Geophys Res 111:8020, 2006); however, at the spectral peak, the similarity with the Pierson-Moskowitz spectrum is clear. These results establish the basis for the use in assessing the ability of numerical models to simulate the wave field in hurricanes.

  5. Ocean surface waves in Hurricane Ike (2008) and Superstorm Sandy (2012): Coupled model predictions and observations

    Science.gov (United States)

    Chen, Shuyi S.; Curcic, Milan

    2016-07-01

    Forecasting hurricane impacts of extreme winds and flooding requires accurate prediction of hurricane structure and storm-induced ocean surface waves days in advance. The waves are complex, especially near landfall when the hurricane winds and water depth varies significantly and the surface waves refract, shoal and dissipate. In this study, we examine the spatial structure, magnitude, and directional spectrum of hurricane-induced ocean waves using a high resolution, fully coupled atmosphere-wave-ocean model and observations. The coupled model predictions of ocean surface waves in Hurricane Ike (2008) over the Gulf of Mexico and Superstorm Sandy (2012) in the northeastern Atlantic and coastal region are evaluated with the NDBC buoy and satellite altimeter observations. Although there are characteristics that are general to ocean waves in both hurricanes as documented in previous studies, wave fields in Ike and Sandy possess unique properties due mostly to the distinct wind fields and coastal bathymetry in the two storms. Several processes are found to significantly modulate hurricane surface waves near landfall. First, the phase speed and group velocities decrease as the waves become shorter and steeper in shallow water, effectively increasing surface roughness and wind stress. Second, the bottom-induced refraction acts to turn the waves toward the coast, increasing the misalignment between the wind and waves. Third, as the hurricane translates over land, the left side of the storm center is characterized by offshore winds over very short fetch, which opposes incoming swell. Landfalling hurricanes produce broader wave spectra overall than that of the open ocean. The front-left quadrant is most complex, where the combination of windsea, swell propagating against the wind, increasing wind-wave stress, and interaction with the coastal topography requires a fully coupled model to meet these challenges in hurricane wave and surge prediction.

  6. Simulation of hurricane response to suppression of warm rain by sub-micron aerosols

    Directory of Open Access Journals (Sweden)

    D. Rosenfeld

    2007-07-01

    Full Text Available The feasibility of hurricane modification was investigated for hurricane Katrina using the Weather Research and Forecasting Model (WRF. The possible impact of seeding of clouds with submicron cloud condensation nuclei (CCN on hurricane structure and intensity as measured by nearly halving of the area covered by hurricane force winds was simulated by "turning–off" warm rain formation in the clouds at Katrina's periphery (where wind speeds were less than 22 m s−1. This simplification of the simulation of aerosol effects is aimed at evaluating the largest possible response. This resulted in the weakening of the hurricane surface winds compared to the "non-seeded" simulated storm during the first 24 h within the entire tropical cyclone (TC area compared to a control simulation without warm rain suppression. Later, the seeding-induced evaporative cooling at the TC periphery led to a shrinking of the eye and hence to some increase in the wind within the small central area of the TC. Yet, the overall strength of the hurricane, as defined by the area covered by hurricane force winds, decreased in response to the suppressed warm rain at the periphery, as measured by a 25% reduction in the radius of hurricane force winds. In a simulation with warm rain suppression throughout the hurricane, the radius of the hurricane force winds was reduced by more than 42%, and although the diameter of the eye shrunk even further the maximum winds weakened. This shows that the main mechanism by which suppressing warm rain weakens the TC is the low level evaporative cooling of the un-precipitated cloud drops and the added cooling due to melting of precipitation that falls from above.

  7. Retrieving mesospheric winds and gravity waves using high resolution radar measurements of polar mesospheric summer echoes with MAARSY

    Science.gov (United States)

    Stober, G.; Sommer, S.; Schult, C.; Chau, J. L.; Latteck, R.

    2013-12-01

    The Middle Atmosphere Alomar Radar System (MAARSY) located at the northern Norwegian island of Andøya (69.3 ° N, 16° E) observes polar mesosphere summer echoes (PMSE) on a regular basis. This backscatter turned out to be an ideal tracer of atmospheric dynamics and to investigate the wind field at the mesosphere/lower thermosphere (MLT) at high spatial and temporal scales. MAARSY is dedicated to explore the polar mesosphere at such high resolution and employs an active phased array antenna with the capability to steer the beam on a pulse-to-pulse basis, which permits to perform systematic scanning of PMSE and to investigate the horizontal structure of the backscatter. The radar also uses a 16 channel receiver system for interferometric applications e.g. mean angle of arrival analysis or coherent radar imaging. Here we present measurements using these features of MAARSY to study the wind field at the MLT applying sophisticated wind analysis algorithms such as velocity azimuth display or volume velocity processing to derive gravity wave parameters such as horizontal wave length, phase speed and propagation direction. Further, we compare the interferometrically corrected and uncorrected wind measurements to emphasize the importance to account for likely edge effects using PMSE as tracer of the dynamics. The observations indicate huge deviations from the nominal beam pointing direction at the upper and lower edges of the PMSE altering the wind analysis.

  8. Hurricane Data Analysis Tool

    Science.gov (United States)

    Liu, Zhong; Ostrenga, Dana; Leptoukh, Gregory

    2011-01-01

    In order to facilitate Earth science data access, the NASA Goddard Earth Sciences Data Information Services Center (GES DISC) has developed a web prototype, the Hurricane Data Analysis Tool (HDAT; URL: http://disc.gsfc.nasa.gov/HDAT), to allow users to conduct online visualization and analysis of several remote sensing and model datasets for educational activities and studies of tropical cyclones and other weather phenomena. With a web browser and few mouse clicks, users can have a full access to terabytes of data and generate 2-D or time-series plots and animation without downloading any software and data. HDAT includes data from the NASA Tropical Rainfall Measuring Mission (TRMM), the NASA Quick Scatterometer(QuikSCAT) and NECP Reanalysis, and the NCEP/CPC half-hourly, 4-km Global (60 N - 60 S) IR Dataset. The GES DISC archives TRMM data. The daily global rainfall product derived from the 3-hourly multi-satellite precipitation product (3B42 V6) is available in HDAT. The TRMM Microwave Imager (TMI) sea surface temperature from the Remote Sensing Systems is in HDAT as well. The NASA QuikSCAT ocean surface wind and the NCEP Reanalysis provide ocean surface and atmospheric conditions, respectively. The global merged IR product, also known as, the NCEP/CPC half-hourly, 4-km Global (60 N -60 S) IR Dataset, is one of TRMM ancillary datasets. They are globally-merged pixel-resolution IR brightness temperature data (equivalent blackbody temperatures), merged from all available geostationary satellites (GOES-8/10, METEOSAT-7/5 & GMS). The GES DISC has collected over 10 years of the data beginning from February of 2000. This high temporal resolution (every 30 minutes) dataset not only provides additional background information to TRMM and other satellite missions, but also allows observing a wide range of meteorological phenomena from space, such as, hurricanes, typhoons, tropical cyclones, mesoscale convection system, etc. Basic functions include selection of area of

  9. Recovering from Hurricane Katrina

    Science.gov (United States)

    Coleman, Nadine

    2006-01-01

    The Gulf Coast region suffered an unusually severe hurricane season in 2005: Hurricane Katrina (August 28-29, 2005) devastated much of southern Mississippi and Louisiana. Approximately 2,700 licensed early care and education facilities in those states and in Alabama were affected by Katrina, in addition to an unknown number of family child care…

  10. Multi-beam raindrop size distributions retrievals on the Doppler spectra: Influence of averaging and mean horizontal wind correction

    NARCIS (Netherlands)

    Unal, C.M.H.

    2012-01-01

    Acquiring the raindrop size distribution (DSD) from radar data is still a challenge. For profiling radar, this distribution can be estimated from the Doppler spectra. However the Doppler spectrum is not a direct measure of the DSD. The radial component of the wind shifts the Doppler spectrum related

  11. ON THE RETRIEVAL OF MESOSPHERIC WINDS ON MARS AND VENUS FROM GROUND-BASED OBSERVATIONS AT 10 μm

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Valverde, M. A. [Instituto de Astrofisica de Andalucia, IAA/CSIC, Granada (Spain); Montabone, L. [Space Science Institute, Boulder, CO (United States); Sornig, M.; Sonnabend, G., E-mail: valverde@iaa.es [University of Cologne, KOSMA, Köln (Germany)

    2016-01-10

    A detailed analysis is presented of ground-based observations of atmospheric emissions on Mars and Venus under non-local thermodynamic equilibrium (non-LTE) conditions at high spectral resolution. Our first goal is to comprehend the difficulties behind the derivation of wind speeds from ground-based observations. A second goal is to set a framework to permit comparisons with other observations and with atmospheric models. A forward model including non-LTE radiative transfer is used to evaluate the information content within the telescopic beam, and is later convolved with the beam function and a typical wind field to discern the major contributions to the measured radiance, including limb and nadir views. The emission mostly arises from the non-LTE limb around altitudes of 75 km on Mars and 110 km on Venus. We propose a parameterization of the limb emission using few geophysical parameters which can be extended to other hypothetical CO{sub 2} planetary atmospheres. The tropospheric or LTE component of the emission varies with the temperature and is important at low solar illumination but only for the emerging radiance, not for the wind determinations since these are derived from the Doppler shift at the non-LTE line cores. We evaluated the sources of uncertainty and found that the forward model errors amount to approximately 12% of the measured winds, which is normally smaller than the instrumental errors. We applied this study to revise a set of measurements extending for three Martian years and confirmed previous results suggesting winds that are too large simulated by current Martian circulation models at equatorial latitudes during solstice. We encourage new observational campaigns, particularly for the strong jet at mid–high latitudes on Mars, and propose general guidelines and recommendations for future observations.

  12. Infrasonic ray tracing applied to mesoscale atmospheric structures: refraction by hurricanes.

    Science.gov (United States)

    Bedard, Alfred J; Jones, R Michael

    2013-11-01

    A ray-tracing program is used to estimate the refraction of infrasound by the temperature structure of the atmosphere and by hurricanes represented by a Rankine-combined vortex wind plus a temperature perturbation. Refraction by the hurricane winds is significant, giving rise to regions of focusing, defocusing, and virtual sources. The refraction of infrasound by the temperature anomaly associated with a hurricane is small, probably no larger than that from uncertainties in the wind field. The results are pertinent to interpreting ocean wave generated infrasound in the vicinities of tropical cyclones.

  13. Hurricane Ike: Field Investigation Survey (Invited)

    Science.gov (United States)

    Ewing, L.

    2009-12-01

    Hurricane Ike made landfall at 2:10 a.m. on September 13, 2008, as a Category 2 hurricane. The eye of the hurricane crossed over the eastern end of Galveston Island and a large region of the Texas and Louisiana coast experienced extreme winds, waves and water levels, resulting in large impacts from overtopping, overwash, wind and wave forces and flooding. Major damage stretched from Freeport to the southwest and to Port Arthur to the northeast. The effects of the hurricane force winds were felt well inland in Texas and Louisiana and the storm continued to the interior of the US, causing more damage and loss of life. Through the support of the Coasts, Oceans, Ports and Rivers Institute (COPRI) of the American Society of Civil Engineers (ASCE) a team of 14 coastal scientists and engineers inspected the upper Texas coast in early October 2008. The COPRI team surveyed Hurricane Ike’s effects on coastal landforms, structures, marinas, shore protection systems, and other infrastructure. Damages ranges from very minor to complete destruction, depending upon location and elevation. Bolivar Peninsula, to the right of the hurricane path, experienced severe damage and three peninsula communities were completely destroyed. Significant flood and wave damage also was observed in Galveston Island and Brazoria County that were both on the left side of the hurricane path. Beach erosion and prominent overwash fans were observed throughout much of the field investigation area. The post-storm damage survey served to confirm expected performance under extreme conditions, as well as to evaluate recent development trends and conditions unique to each storm. Hurricane Ike confirmed many previously reported observations. One of the main conclusions from the inspection of buildings was that elevation was a key determinant for survival. Elevation is also a major factor in the stability and effectiveness of shore protection. The Galveston Seawall was high enough to provide protection from

  14. Development and Evaluation of New Algorithms for the Retrieval of Wind and Internal Wave Parameters from Shipborne Marine Radar Data

    Science.gov (United States)

    2012-12-01

    10 m above sea surface (U10), with friction velocity and drag coefficient computed according to Smith [111]. Note that neutral conditions and wind sea...buoy and tether signal, which show as bright points against a dark back- ground. Before the IW’s arrival, the ASIS buoy was acting like a weather vane ...Radio Sci., 15(3):605–615, 1980. 183 [93] S. Popinet, M. Smith , and C. Stevens. Experimental and numerical study of the turbulence characteristics of

  15. Hurricane! Coping With Disaster

    Science.gov (United States)

    Lifland, Jonathan

    A new AGU book, Hurricane! Coping With Disaster, analyzes the progress made in hurricane science and recounts how advances in the field have affected the public's and the scientific community's understanding of these storms. The book explores the evolution of hurricane study, from the catastrophic strike in Galveston, Texas in 1900—still the worst natural disaster in United States history—to today's satellite and aircraft observations that track a storm's progress and monitor its strength. In this issue, Eos talks with Robert Simpson, the books' senior editor.Simpson has studied severe storms for more than 60 years, including conducting one of the first research flights through a hurricane in 1945. He was the founding director of the (U.S.) National Hurricane Research Project and has served as director of the National Hurricane Center. In collaboration with Herbert Saffir, Simpson helped design and implement the Saffir/Simpson damage potential scale that is widely used to identify potential damage from hurricanes.

  16. Shelf sediment transport during hurricanes Katrina and Rita

    Science.gov (United States)

    Xu, Kehui; Mickey, Rangley C.; Chen, Qin; Harris, Courtney K.; Hetland, Robert D.; Hu, Kelin; Wang, Jiaze

    2016-05-01

    Hurricanes can greatly modify the sedimentary record, but our coastal scientific community has rather limited capability to predict hurricane-induced sediment deposition. A three-dimensional sediment transport model was developed in the Regional Ocean Modeling System (ROMS) to study seabed erosion and deposition on the Louisiana shelf in response to Hurricanes Katrina and Rita in the year 2005. Sensitivity tests were performed on both erosional and depositional processes for a wide range of erosional rates and settling velocities, and uncertainty analysis was done on critical shear stresses using the polynomial chaos approximation method. A total of 22 model runs were performed in sensitivity and uncertainty tests. Estimated maximum erosional depths were sensitive to the inputs, but horizontal erosional patterns seemed to be controlled mainly by hurricane tracks, wave-current combined shear stresses, seabed grain sizes, and shelf bathymetry. During the passage of two hurricanes, local resuspension and deposition dominated the sediment transport mechanisms. Hurricane Katrina followed a shelf-perpendicular track before making landfall and its energy dissipated rapidly within about 48 h along the eastern Louisiana coast. In contrast, Hurricane Rita followed a more shelf-oblique track and disturbed the seabed extensively during its 84-h passage from the Alabama-Mississippi border to the Louisiana-Texas border. Conditions to either side of Hurricane Rita's storm track differed substantially, with the region to the east having stronger winds, taller waves and thus deeper erosions. This study indicated that major hurricanes can disturb the shelf at centimeter to meter levels. Each of these two hurricanes suspended seabed sediment mass that far exceeded the annual sediment inputs from the Mississippi and Atchafalaya Rivers, but the net transport from shelves to estuaries is yet to be determined. Future studies should focus on the modeling of sediment exchange between

  17. 33 CFR 203.49 - Rehabilitation of Hurricane and Shore Protection Projects.

    Science.gov (United States)

    2010-07-01

    ... Shore Protection Projects. 203.49 Section 203.49 Navigation and Navigable Waters CORPS OF ENGINEERS... authorized hurricane or shore protection structure damaged or destroyed by wind, wave, or water action of an... of damage to a Hurricane/Shore Protection Project. “Prolongation or severity” means a Category 3...

  18. ENVIRONMENTAL CONDITIONS IN NORTHERN GULF OF MEXICO COASTAL WATERS FOLLOWING HURRICANE KATRINA

    Science.gov (United States)

    On the morning of August 29, 2005 Hurricane Katrina struck the coast of Louisiana, between New Orleans and Biloxi, Mississippi, as a strong category three hurricane on the Saffir-Simpson scale. The massive winds and flooding had the potential for a tremendous environmental impac...

  19. Cooperative Hurricane Network Obs

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Observations from the Cooperative Hurricane Reporting Network (CHURN), a special network of stations that provided observations when tropical cyclones approached the...

  20. Hurricane Katrina disaster diplomacy.

    Science.gov (United States)

    Kelman, Ilan

    2007-09-01

    Hurricane Katrina struck the United States at the end of August 2005. The consequent devastation appeared to be beyond the US government's ability to cope with and aid was offered by several states in varying degrees of conflict with the US. Hurricane Katrina therefore became a potential case study for 'disaster diplomacy', which examines how disaster-related activities do and do not yield diplomatic gains. A review of past disaster diplomacy work is provided. The literature's case studies are then categorised using a new typology: propinquity, aid relationship, level and purpose. Hurricane Katrina and its aftermath are then placed in the context of the US government's foreign policy, the international response to the disaster and the US government's reaction to these responses. The evidence presented is used to discuss the potential implications of Hurricane Katrina disaster diplomacy, indicating that factors other than disaster-related activities generally dominate diplomatic relations and foreign policy.

  1. Hurricane Matthew overwash extents

    Science.gov (United States)

    Doran, Kara; Long, Joseph W.; Birchler, Justin; Range, Ginger

    2017-01-01

    The National Assessment of Coastal Change Hazards project exists to understand and predict storm impacts to our nation's coastlines. This data defines the alongshore extent of overwash deposits attributed to coastal processes during Hurricane Matthew.

  2. Hurricane Katrina Water Sampling

    Science.gov (United States)

    Hurricane Katrina made landfall in August 2005, causing widespread devastation along the Gulf Coast of the United States. EPA emergency response personnel worked with FEMA and state and local agencies to respond to the emergencies throughout the Gulf.

  3. Hurricane Katrina Sediment Sampling

    Science.gov (United States)

    Hurricane Katrina made landfall in August 2005, causing widespread devastation along the Gulf Coast of the United States. EPA emergency response personnel worked with FEMA and state and local agencies to respond to the emergencies throughout the Gulf.

  4. Hurricane Katrina Soil Sampling

    Science.gov (United States)

    Hurricane Katrina made landfall in August 2005, causing widespread devastation along the Gulf Coast of the United States. EPA emergency response personnel worked with FEMA and state and local agencies to respond to the emergencies throughout the Gulf.

  5. Hurricane Katrina Water Sampling

    Data.gov (United States)

    U.S. Environmental Protection Agency — Hurricane Katrina made landfall in August 2005, causing widespread devastation along the Gulf Coast of the United States. EPA emergency response personnel worked...

  6. Hurricane Katrina Soil Sampling

    Data.gov (United States)

    U.S. Environmental Protection Agency — Hurricane Katrina made landfall in August 2005, causing widespread devastation along the Gulf Coast of the United States. EPA emergency response personnel worked...

  7. Hurricane Katrina Sediment Sampling

    Data.gov (United States)

    U.S. Environmental Protection Agency — Hurricane Katrina made landfall in August 2005, causing widespread devastation along the Gulf Coast of the United States. EPA emergency response personnel worked...

  8. Landslides triggered by Hurricane Mitch in Tegucigalpa, Honduras

    Science.gov (United States)

    Harp, Edwin L.; Castaneda, Mario; Held, Matthew D.

    2002-01-01

    The arrival of Hurricane Mitch in Honduras in the latter part of the 1998 hurricane season produced effects that were unprecedented in their widespread nature throughout Central America. After winds from the storm had blown down more than 70 percent of the conifer forest on the Bay Island of Guanaja, the hurricane turned inland and stalled over the mainland of Honduras for 3 days. The resulting deluge of rainfall produced devastating flooding and landslides that resulted in more than 9,000 fatalities and 3 million people displaced. Although the eye of Hurricane Mitch passed through the northern part of Honduras, the greatest rainfall totals and intensities occurred in the southern part of the country near Choluteca. For the three days October 29-31, 1998, total rainfall at Choluteca exceeded 900 mm. Not surprisingly, it was in this area that the highest landslide concentrations occurred.

  9. Continental United States Hurricane Strikes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Continental U.S. Hurricane Strikes Poster is our most popular poster which is updated annually. The poster includes all hurricanes that affected the U.S. since...

  10. Lagrangian mixing in an axisymmetric hurricane model

    Directory of Open Access Journals (Sweden)

    B. Rutherford

    2009-09-01

    Full Text Available This paper discusses the extension of established Lagrangian mixing measures to make them applicable to data extracted from a 2-D axisymmetric hurricane simulation. Because of the non-steady and unbounded characteristics of the simulation, the previous measures are extended to a moving frame approach to create time-dependent mixing rates that are dependent upon the initial time of particle integration, and are computed for nonlocal regions. The global measures of mixing derived from finite-time Lyapunov exponents, relative dispersion, and a measured mixing rate are applied to distinct regions representing different characteristic feautures within the model. It is shown that these time-dependent mixing rates exhibit correlations with maximal tangential winds during a quasi-steady state, establishing a connection between mixing and hurricane intensity.

  11. Using a Geographic Information System to Assess the Risk of Hurricane Hazards on the Maya Civilization

    Science.gov (United States)

    Weigel, A. M.; Griffin, R.; Sever, T.

    2014-12-01

    The extent of the Maya civilization spanned across portions of modern day Mexico, Belize, Guatemala, El Salvador and Honduras. Paleoclimatic studies suggest this region has been affected by strong hurricanes for the past six thousand years, reinforced by archeological evidence from Mayan records indicating they experienced strong storms. It is theorized hurricanes aided in the collapse of the Maya, damaging building structures, agriculture, and ceasing industry activities. Today, this region is known for its active tropical climatology, being hit by numerous strong storms including Hurricane Dean, Iris, Keith, and Mitch. This research uses a geographic information system (GIS) to model hurricane hazards, and assess the risk posed on the Maya civilization. GIS has the ability to handle various layer components making it optimal for combining parameters necessary for assessing the risk of experiencing hurricane related hazards. For this analysis, high winds, storm surge flooding, non-storm surge related flooding, and rainfall triggered landslides were selected as the primary hurricane hazards. Data sets used in this analysis include the National Climatic Data Center International Best Track Archive for Climate Stewardships (IBTrACS) hurricane tracks, Shuttle Radar Topography Mission Digital Elevation Model, WorldClim monthly accumulated precipitation, USGS HydroSHEDS river locations, Harmonized World Soil Database soil types, and known Maya site locations from the Electronic Atlas of Ancient Maya Sites. ArcGIS and ENVI software were utilized to process data and model hurricane hazards. To assess locations at risk of experiencing high winds, a model was created using ArcGIS Model Builder to map each storm's temporal wind profile, and adapted to simulate forward storm velocity, and storm frequency. Modeled results were then combined with physical land characteristics, meteorological, and hydrologic data to identify areas likely affected. Certain areas along the eastern

  12. Hurricane Katrina: A Teachable Moment

    Science.gov (United States)

    Bertrand, Peggy

    2009-01-01

    This article presents suggestions for integrating the phenomenon of hurricanes into the teaching of high school fluid mechanics. Students come to understand core science concepts in the context of their impact upon both the environment and human populations. Suggestions for using information about hurricanes, particularly Hurricane Katrina, in a…

  13. Hurricane Katrina: A Teachable Moment

    Science.gov (United States)

    Bertrand, Peggy

    2009-01-01

    This article presents suggestions for integrating the phenomenon of hurricanes into the teaching of high school fluid mechanics. Students come to understand core science concepts in the context of their impact upon both the environment and human populations. Suggestions for using information about hurricanes, particularly Hurricane Katrina, in a…

  14. Case study on visualizing hurricanes using illustration-inspired techniques.

    Science.gov (United States)

    Joshi, Alark; Caban, Jesus; Rheingans, Penny; Sparling, Lynn

    2009-01-01

    The devastating power of hurricanes was evident during the 2005 hurricane season, the most active season on record. This has prompted increased efforts by researchers to understand the physical processes that underlie the genesis, intensification, and tracks of hurricanes. This research aims at facilitating an improved understanding into the structure of hurricanes with the aid of visualization techniques. Our approach was developed by a mixed team of visualization and domain experts. To better understand these systems, and to explore their representation in NWP models, we use a variety of illustration-inspired techniques to visualize their structure and time evolution. Illustration-inspired techniques aid in the identification of the amount of vertical wind shear in a hurricane, which can help meteorologists predict dissipation. Illustration-style visualization, in combination with standard visualization techniques, helped explore the vortex rollup phenomena and the mesovortices contained within. We evaluated the effectiveness of our visualization with the help of six hurricane experts. The expert evaluation showed that the illustration-inspired techniques were preferred over existing tools. Visualization of the evolution of structural features is a prelude to a deeper visual analysis of the underlying dynamics.

  15. Wave and Wind Direction Effects on SFMR Brightness Temperatures

    Science.gov (United States)

    Holbach, Heather; Uhlhorn, Eric; Bourassa, Mark

    2015-04-01

    Surface winds in a tropical cyclone are essential for determining its strength. Currently the Stepped-Frequency Microwave Radiometer (SFMR) and Global Positioning System (GPS) dropwindsondes are the main instruments used for obtaining in situ surface wind measurements. The platforms for these instruments are the National Oceanographic and Atmospheric Administration (NOAA) P-3 and Air Force C-130J hurricane hunter aircraft. The SFMR measures sea surface microwave brightness temperatures at six frequencies ranging from 4.7 to 7.2 GHz. Surface wind speed estimates are obtained from these brightness temperatures by using a retrieval algorithm that employs a geophysical model function relating surface emissivity and wind speed. The SFMR is designed to obtain a single nadir track of surface wind speeds directly beneath the aircraft during level flight and not when turning because of the complexity of the wave field and foam distribution when the SFMR views the surface off-nadir or during aircraft rolls. However, the effects of the wave field on the measurements can be investigated using measurements obtained during the 2008 and 2014 Atlantic hurricane seasons. An SFMR module was flown in precipitation-free regions of the tropical cyclones to collect data at specified roll angles of 15°, 30°, 45°, and 60° in some cases. Excess brightness temperatures are then calculated with respect to zero wind speed values and independent of wind direction. An asymmetry is found in the resulting excess brightness temperatures. It is hypothesized that this asymmetry is caused by the direction of wave propagation and the angle at which the wave field is viewed by the SFMR. Wind direction may also play a role in the asymmetry. To analyze the asymmetry further measurement from WindSat will be used. Once the relationship is determined between surface wind speed, brightness temperature, and incidence angle a technique will be developed to obtain a surface wind speed when the aircraft is

  16. Gaussian and Lognormal Models of Hurricane Gust Factors

    Science.gov (United States)

    Merceret, Frank

    2009-01-01

    A document describes a tool that predicts the likelihood of land-falling tropical storms and hurricanes exceeding specified peak speeds, given the mean wind speed at various heights of up to 500 feet (150 meters) above ground level. Empirical models to calculate mean and standard deviation of the gust factor as a function of height and mean wind speed were developed in Excel based on data from previous hurricanes. Separate models were developed for Gaussian and offset lognormal distributions for the gust factor. Rather than forecasting a single, specific peak wind speed, this tool provides a probability of exceeding a specified value. This probability is provided as a function of height, allowing it to be applied at a height appropriate for tall structures. The user inputs the mean wind speed, height, and operational threshold. The tool produces the probability from each model that the given threshold will be exceeded. This application does have its limits. They were tested only in tropical storm conditions associated with the periphery of hurricanes. Winds of similar speed produced by non-tropical system may have different turbulence dynamics and stability, which may change those winds statistical characteristics. These models were developed along the Central Florida seacoast, and their results may not accurately extrapolate to inland areas, or even to coastal sites that are different from those used to build the models. Although this tool cannot be generalized for use in different environments, its methodology could be applied to those locations to develop a similar tool tuned to local conditions.

  17. Hurricane Risk Variability along the Gulf of Mexico Coastline

    Science.gov (United States)

    Trepanier, Jill C.; Ellis, Kelsey N.; Tucker, Clay S.

    2015-01-01

    Hurricane risk characteristics are examined across the U. S. Gulf of Mexico coastline using a hexagonal tessellation. Using an extreme value model, parameters are collected representing the rate or λ (frequency), the scale or σ (range), and the shape or ξ (intensity) of the extreme wind distribution. These latent parameters and the 30-year return level are visualized across the grid. The greatest 30-year return levels are located toward the center of the Gulf of Mexico, and for inland locations, along the borders of Louisiana, Mississippi, and Alabama. Using a geographically weighted regression model, the relationship of these parameters to sea surface temperature (SST) is found to assess sensitivity to change. It is shown that as SSTs increase near the coast, the frequency of hurricanes in these grids decrease significantly. This reinforces the importance of SST in areas of likely tropical cyclogenesis in determining the number of hurricanes near the coast, along with SSTs along the lifespan of the storm, rather than simply local SST. The range of hurricane wind speeds experienced near Florida is shown to increase with increasing SSTs (insignificant), suggesting that increased temperatures may allow hurricanes to maintain their strength as they pass over the Florida peninsula. The modifiable areal unit problem is assessed using multiple grid sizes. Moran’s I and the local statistic G are calculated to examine spatial autocorrelation in the parameters. This research opens up future questions regarding rapid intensification and decay close to the coast and the relationship to changing SSTs. PMID:25767885

  18. Hurricane risk variability along the Gulf of Mexico coastline.

    Directory of Open Access Journals (Sweden)

    Jill C Trepanier

    Full Text Available Hurricane risk characteristics are examined across the U. S. Gulf of Mexico coastline using a hexagonal tessellation. Using an extreme value model, parameters are collected representing the rate or λ (frequency, the scale or σ (range, and the shape or ξ (intensity of the extreme wind distribution. These latent parameters and the 30-year return level are visualized across the grid. The greatest 30-year return levels are located toward the center of the Gulf of Mexico, and for inland locations, along the borders of Louisiana, Mississippi, and Alabama. Using a geographically weighted regression model, the relationship of these parameters to sea surface temperature (SST is found to assess sensitivity to change. It is shown that as SSTs increase near the coast, the frequency of hurricanes in these grids decrease significantly. This reinforces the importance of SST in areas of likely tropical cyclogenesis in determining the number of hurricanes near the coast, along with SSTs along the lifespan of the storm, rather than simply local SST. The range of hurricane wind speeds experienced near Florida is shown to increase with increasing SSTs (insignificant, suggesting that increased temperatures may allow hurricanes to maintain their strength as they pass over the Florida peninsula. The modifiable areal unit problem is assessed using multiple grid sizes. Moran's I and the local statistic G are calculated to examine spatial autocorrelation in the parameters. This research opens up future questions regarding rapid intensification and decay close to the coast and the relationship to changing SSTs.

  19. Hurricane risk variability along the Gulf of Mexico coastline.

    Science.gov (United States)

    Trepanier, Jill C; Ellis, Kelsey N; Tucker, Clay S

    2015-01-01

    Hurricane risk characteristics are examined across the U. S. Gulf of Mexico coastline using a hexagonal tessellation. Using an extreme value model, parameters are collected representing the rate or λ (frequency), the scale or σ (range), and the shape or ξ (intensity) of the extreme wind distribution. These latent parameters and the 30-year return level are visualized across the grid. The greatest 30-year return levels are located toward the center of the Gulf of Mexico, and for inland locations, along the borders of Louisiana, Mississippi, and Alabama. Using a geographically weighted regression model, the relationship of these parameters to sea surface temperature (SST) is found to assess sensitivity to change. It is shown that as SSTs increase near the coast, the frequency of hurricanes in these grids decrease significantly. This reinforces the importance of SST in areas of likely tropical cyclogenesis in determining the number of hurricanes near the coast, along with SSTs along the lifespan of the storm, rather than simply local SST. The range of hurricane wind speeds experienced near Florida is shown to increase with increasing SSTs (insignificant), suggesting that increased temperatures may allow hurricanes to maintain their strength as they pass over the Florida peninsula. The modifiable areal unit problem is assessed using multiple grid sizes. Moran's I and the local statistic G are calculated to examine spatial autocorrelation in the parameters. This research opens up future questions regarding rapid intensification and decay close to the coast and the relationship to changing SSTs.

  20. Hurricane Isaac: A Longitudinal Analysis of Storm Characteristics and Power Outage Risk.

    Science.gov (United States)

    Tonn, Gina L; Guikema, Seth D; Ferreira, Celso M; Quiring, Steven M

    2016-10-01

    In August 2012, Hurricane Isaac, a Category 1 hurricane at landfall, caused extensive power outages in Louisiana. The storm brought high winds, storm surge, and flooding to Louisiana, and power outages were widespread and prolonged. Hourly power outage data for the state of Louisiana were collected during the storm and analyzed. This analysis included correlation of hourly power outage figures by zip code with storm conditions including wind, rainfall, and storm surge using a nonparametric ensemble data mining approach. Results were analyzed to understand how correlation of power outages with storm conditions differed geographically within the state. This analysis provided insight on how rainfall and storm surge, along with wind, contribute to power outages in hurricanes. By conducting a longitudinal study of outages at the zip code level, we were able to gain insight into the causal drivers of power outages during hurricanes. Our analysis showed that the statistical importance of storm characteristic covariates to power outages varies geographically. For Hurricane Isaac, wind speed, precipitation, and previous outages generally had high importance, whereas storm surge had lower importance, even in zip codes that experienced significant surge. The results of this analysis can inform the development of power outage forecasting models, which often focus strictly on wind-related covariates. Our study of Hurricane Isaac indicates that inclusion of other covariates, particularly precipitation, may improve model accuracy and robustness across a range of storm conditions and geography.

  1. New method of sea surface wind speed retrieval using genetic algorithms and neural network%基于遗传神经网络算法的海面风速反演新方法

    Institute of Scientific and Technical Information of China (English)

    石汉青; 张雷; 杜华栋; 龙智勇; 姜世泰

    2013-01-01

    There exist the complexity of sea surface and the limitation of theoretical model of electromagnet-ic scattering,and nonlinear phenomena in the retrieval of sea surface wind speed,which is based on syn-thetic aperture radar (SAR)images.With the method of genetic neural network and Fletcher-Reeves,this paper established a new model of retrieving wind speed based on operational data of CMOD4 model func-tion.The result shows that this model is available in retrieving ocean surface wind.When random error is less than 10%,this model has high denoising ability and the accuracy of the retrieved ocean surface wind speed is ideal.Comparing the results of different wind speed,shows that in the case of low or middle wind,the fitness of learning model and the accuracy of predicted tests have both ideal accuracy,and that in the case of strong wind,the inversion result of this model is comparatively poor.%针对海面运动的复杂性、海面电磁散射理论模型的局限性以及利用 SAR 图像反演海面风速存在的非线性现象,基于遗传神经网络的方法,以业务化的 CMOD4模式函数数据为基础,采用 Fletcher-Reeves 算法的变梯度反向传播算法,建立一种 SAR 风速反演的新模型。试验结果表明,利用遗传神经网络方法反演海面风速是可行的,当随机误差小于10%时,模型的抗噪能力较强,风速反演的精度较为理想。比较不同风速下的反演结果可以发现,在中、小风速的情况下,模型的抗噪能力较强,模型学习拟合和预测检验的精度相对较高;在大风速的情况下,模型的反演能力有待于进一步提高。

  2. Average velocity field of the air flow over the water surface in a laboratory modeling of storm and hurricane conditions in the ocean

    Science.gov (United States)

    Kandaurov, A. A.; Troitskaya, Yu. I.; Sergeev, D. A.; Vdovin, M. I.; Baidakov, G. A.

    2014-07-01

    Laboratory experiments on studying the structure of the turbulent air boundary layer over waves were carried out at the Wind-Wave Channel of the Institute of Applied Physics, Russian Academy of Sciences (IAP RAS), in conditions modeling the near-water boundary layer of the atmosphere under strong and hurricane winds and the equivalent wind velocities from 10 to 48 m/s at the standard height of 10 m. A modified technique of Particle Image Velocimetry (PIV) was used to obtain turbulent pulsation averaged velocity fields of the air flow over the water surface curved by a wave and average profiles of the wind velocity. The measurements showed that the logarithmic part of the velocity profile of the air flow in the channel was observed in the immediate vicinity from the water surface (at a distance of 30 mm) and could be detected only using remote methods (PIV). According to the measured velocity profiles, dependences of aerodynamic drag factors of the water surface on the wind velocity at a height of 10 m were retrieved; they were compared with results of contact measurements carried out earlier on the same setup. It is shown that they agree with an accuracy of up to 20%; at moderate and strong wind velocities the coincidence falls within the experimental accuracy.

  3. Shearing Wind Helicity and Thermal Wind Helicity

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Helicity is defined as H=V.ω, where V and ω are the velocity and vorticity vectors, respectively.Many works have pointed out that the larger the helicity is, the longer the life cycle of the weather system is. However, the direct relationship of the helicity to the evolution of the weather system is not quite clear. In this paper, the concept of helicity is generalized as shearing wind helicity (SWH). Dynamically,it is found that the average SWH is directly related to the increase of the average cyclonic rotation of the weather system. Physically, it is also pointed out that the SWH, as a matter of fact, is the sum of the torsion terms and the divergence term in the vorticity equation. Thermal wind helicity (TWH), as a derivative of SWH, is also discussed here because it links the temperature field and the vertical wind field. These two quantities may be effective for diagnosing a weather system. This paper applies these two quantities in cylindrical coordinates to study the development of Hurricane Andrew to validate their practical use. Through analyzing the hurricane, it is found that TWH can well describe the characteristics of the hurricane such as the strong convection and release of latent heat. SWH is not only a good quantity for diagnosing the weather system, but also an effective one for diagnosing the development of the hurricane.

  4. Quantifying Hurricane Wind Speed with Undersea Sound

    Science.gov (United States)

    2006-06-01

    656-666, 1997. [91] A. Papoulis and S. U. Pillai. Probability, random variables and stochastic pro- cesses, page 515. McGraw-Hill, New York, 1965. 163...92] A. Papoulis and S. U. Pillai. Probability, Random Variables and Stochastic Processes, pages 515, 2012-2014. McGraw-Hill, New York, 2002. [93] R. J

  5. The Ocean Boundary Layer beneath Hurricane Frances

    Science.gov (United States)

    Dasaro, E. A.; Sanford, T. B.; Terrill, E.; Price, J.

    2006-12-01

    The upper ocean beneath the peak winds of Hurricane Frances (57 m/s) was measured using several varieties of air-deployed floats as part of CBLAST. A multilayer structure was observed as the boundary layer deepened from 20m to 120m in about 12 hours. Bubbles generated by breaking waves create a 10m thick surface layer with a density anomaly, due to the bubbles, of about 1 kg/m3. This acts to lubricate the near surface layer. A turbulent boundary layer extends beneath this to about 40 m depth. This is characterized by large turbulent eddies spanning the boundary layer. A stratified boundary layer grows beneath this reaching 120m depth. This is characterized by a gradient Richardson number of 1/4, which is maintained by strong inertial currents generated by the hurricane, and smaller turbulent eddies driven by the shear instead of the wind and waves. There is little evidence of mixing beneath this layer. Heat budgets reveal the boundary layer to be nearly one dimensional through much of the deepening, with horizontal and vertical heat advection becoming important only after the storm had passed. Turbulent kinetic energy measurements support the idea of reduced surface drag at high wind speeds. The PWP model correctly predicts the degree of mixed layer deepening if the surface drag is reduced at high wind speed. Overall, the greatest uncertainty in understanding the ocean boundary layer at these extreme wind speeds is a characterization of the near- surface processes which govern the air-sea fluxes and surface wave properties.

  6. Simulation of hurricane response to suppression of warm rain by sub-micron aerosols

    Directory of Open Access Journals (Sweden)

    D. Rosenfeld

    2007-04-01

    Full Text Available The feasibility of hurricane modification was investigated for hurricane Katrina using the Weather Research and Forecasting Model (WRF. The possible impact of seeding of clouds with submicron cloud condensation nuclei (CCN on hurricane structure and intensity as measured by nearly halving of the area covered by hurricane force winds was simulated by "turning–off" warm rain formation in the clouds at Katrina's periphery (where wind speeds were less than 22 m s−1. This simplification of the simulation of aerosol effects is aimed at evaluating the largest possible response. This resulted in the weakening of the hurricane surface winds compared to the "non-seeded" simulated storm during the first 24 h within the entire tropical cyclone (TC area compared to a control simulation without warm rain suppression. Later, the seeding-induced evaporative cooling at the TC periphery led to a shrinking of the eye and hence to some increase in the wind within the small central area of the TC. Yet, the overall strength of the hurricane decreased in response to the suppressed warm rain at the periphery, as measured by a 25% reduction in the radius of hurricane force winds. In a simulation with warm rain suppression throughout the hurricane, the relative weakening compared to the control continued throughout the simulations and the eye shrunk even further. This shows that the main mechanism by which suppressing warm rain weakens the TC is the low level evaporative cooling of the un-precipitated cloud drops and the added cooling due to melting of precipitation that falls from above.

  7. Hurricane Rita Poster (September 22, 2005)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hurricane Rita poster. Multi-spectral image from NOAA-16 shows Hurricane Rita as a category-4 hurricane in the Gulf of Mexico on September 22, 2005. Poster size is...

  8. Hurricane Katrina Poster (August 28, 2005)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hurricane Katrina poster. Multi-spectral image from NOAA-18 shows a very large Hurricane Katrina as a category 5 hurricane in the Gulf of Mexico on August 28, 2005....

  9. An improved wind speed algorithm for“Jason-1”altimeter under tropical cyclone conditions

    Institute of Scientific and Technical Information of China (English)

    QIN Bangyong; ZHOU Xuan; ZHANG Honglei; YANG Xiaofeng; LU Rong; YU Yang; SHI Lijian

    2014-01-01

    Rain effect and lack of in situ validation data are two main causes of tropical cyclone wind retrieval errors. The National Oceanic and Atmospheric Administration’s Climate Prediction Center Morphing technique (CMORPH) rain rate is introduced to a match-up dataset and then put into a rain correction model to re-move rain effects on“Jason-1”normalized radar cross section (NRCS);Hurricane Research Division (HRD) wind speed, which integrates all available surface weather observations, is used to substitute in situ data for establishing this relationship with“Jason-1”NRCS. Then, an improved“Jason-1”wind retrieval algorithm under tropical cyclone conditions is proposed. Seven tropical cyclones from 2003 to 2010 are studied to validate the new algorithm. The experimental results indicate that the standard deviation of this algorithm at C-band and Ku-band is 1.99 and 2.75 m/s respectively, which is better than the existing algorithms. In addition, the C-band algorithm is more suitable for sea surface wind retrieval than Ku-band under tropical cyclone conditions.

  10. Persistent influence of tropical North Atlantic wintertime sea surface temperature on the subsequent Atlantic hurricane season

    Science.gov (United States)

    Wang, Xidong; Liu, Hailong; Foltz, Gregory R.

    2017-08-01

    This study explores the seasonally lagged impact of wintertime sea surface temperature (SST) in the Atlantic main development region (MDR) on the subsequent Atlantic hurricane season. It is found that wintertime SST anomalies in the MDR can persist into the summer, explaining 42% of the variance in the subsequent hurricane season's SST during 1951-2010. An anomalously warm wintertime in the MDR is usually followed by an anomalously active hurricane season. Analysis shows an important constraint on the seasonal evolution of the MDR SST by the water vapor feedback process, in addition to the well-known wind-evaporation-SST and cloud-SST feedback mechanisms over the tropical North Atlantic. The water vapor feedback influences the seasonal evolution of MDR SST by modulating seasonal variations of downward longwave radiation. This wintertime thermal control of hurricane activity has significant implications for seasonal predictions and long-term projections of hurricane activity over the North Atlantic.

  11. Diagnosing United States hurricane landfall risk: An alternative to count-based methodologies

    Science.gov (United States)

    Staehling, Erica M.; Truchelut, Ryan E.

    2016-08-01

    Assessing hurricane landfall risk is of immense public utility, yet extant methods of diagnosing annual tropical cyclone (TC) activity demonstrate no skill in diagnosing U.S. hurricane landfalls. Atlantic TC count itself has limited skill, explaining less than 20% of interannual variance in landfall incidence. Using extended landfall activity and reanalysis data sets, we employed empirical Poisson modeling to produce a landfall diagnostic index (LDI), incorporating spatially and temporally averaged upper level divergence, relative sea surface temperature, meridional wind, and zonal shear vorticity. LDI captures 31% of interannual variability of U.S. hurricane landfalls and offers physical insight into why indices that successfully capture TC activity fail to diagnose landfalls: there is inherent tension between conditions likely to steer hurricanes toward the U.S. and conditions favorable for TC development. Given this tension, attempting to diagnose, predict, or understand TC count is inadequate for quantifying societal impacts due to landfalling hurricanes.

  12. Numerical modeling of the effects of Hurricane Sandy and potential future hurricanes on spatial patterns of salt marsh morphology in Jamaica Bay, New York City

    Science.gov (United States)

    Wang, Hongqing; Chen, Qin; Hu, Kelin; Snedden, Gregg A.; Hartig, Ellen K.; Couvillion, Brady R.; Johnson, Cody L.; Orton, Philip M.

    2017-03-29

    The salt marshes of Jamaica Bay, managed by the New York City Department of Parks & Recreation and the Gateway National Recreation Area of the National Park Service, serve as a recreational outlet for New York City residents, mitigate flooding, and provide habitat for critical wildlife species. Hurricanes and extra-tropical storms have been recognized as one of the critical drivers of coastal wetland morphology due to their effects on hydrodynamics and sediment transport, deposition, and erosion processes. However, the magnitude and mechanisms of hurricane effects on sediment dynamics and associated coastal wetland morphology in the northeastern United States are poorly understood. In this study, the depth-averaged version of the Delft3D modeling suite, integrated with field measurements, was utilized to examine the effects of Hurricane Sandy and future potential hurricanes on salt marsh morphology in Jamaica Bay, New York City. Hurricane Sandy-induced wind, waves, storm surge, water circulation, sediment transport, deposition, and erosion were simulated by using the modeling system in which vegetation effects on flow resistance, surge reduction, wave attenuation, and sedimentation were also incorporated. Observed marsh elevation change and accretion from a rod surface elevation table and feldspar marker horizons and cesium-137- and lead-210-derived long-term accretion rates were used to calibrate and validate the wind-waves-surge-sediment transport-morphology coupled model.The model results (storm surge, waves, and marsh deposition and erosion) agreed well with field measurements. The validated modeling system was then used to detect salt marsh morphological change due to Hurricane Sandy across the entire Jamaica Bay over the short-term (for example, 4 days and 1 year) and long-term (for example, 5 and 10 years). Because Hurricanes Sandy (2012) and Irene (2011) were two large and destructive tropical cyclones which hit the northeast coast, the validated coupled

  13. Unique Meteorological Data During Hurricane Ike's Passage Over Houston

    Science.gov (United States)

    Schade, Gunnar; Rappenglück, Bernhard

    2009-06-01

    Hurricane Ike passed over the Houston, Tex., metropolitan area during the early morning of 13 September 2008. Although Ike had been rated only a category 2 on the Saffir-Simpson scale at landfall near Galveston, Tex., the storm's widespread damage to urban trees, many lacking proper trimming, knocked out the area's power distribution system; for some customers, power was only restored a month later. The hurricane's path after landfall (Figure 1a) went north through Galveston Bay and Baytown. The city of Houston—with its economically important ship channel—experienced the less severe western eye wall, the tight circulation with maximum wind speeds around the hurricane'ps center. The eye's passage was recorded between 3:00 and 4:30 A.M. Central Standard Time (CST; Figures 1a and 1c). It had maintained its unusually large diameter of 35-40 kilometers in its first hours after landfall.

  14. Genesis and maintenance of "Mediterranean hurricanes"

    Directory of Open Access Journals (Sweden)

    K. Emanuel

    2005-01-01

    Full Text Available Cyclonic storms that closely resemble tropical cyclones in satellite images occasionally form over the Mediterranean Sea. Synoptic and mesoscale analyses of such storms show small, warm-core structure and surface winds sometimes exceeding 25ms-1 over small areas. These analyses, together with numerical simulations, reveal that in their mature stages, such storms intensify and are maintained by a feedback between surface enthalpy fluxes and wind, and as such are isomorphic with tropical cyclones. In this paper, I demonstrate that a cold, upper low over the Mediterranean can produce strong cyclogenesis in an axisymmetric model, thereby showing that baroclinic instability is not necessary during the mature stages of Mediterranean hurricanes.

  15. Cold wake of Hurricane Frances

    Science.gov (United States)

    D'Asaro, Eric A.; Sanford, Thomas B.; Niiler, P. Peter; Terrill, Eric J.

    2007-08-01

    An array of instruments air-deployed ahead of Hurricane Frances measured the three-dimensional, time dependent response of the ocean to this strong (60 ms-1) storm. Sea surface temperature cooled by up to 2.2°C with the greatest cooling occurring in a 50-km-wide band centered 60-85 km to the right of the track. The cooling was almost entirely due to vertical mixing, not air-sea heat fluxes. Currents of up to 1.6 ms-1 and thermocline displacements of up to 50 m dispersed as near-inertial internal waves. The heat in excess of 26°C, decreased behind the storm due primarily to horizontal advection of heat away from the storm track, with a small contribution from mixing across the 26°C isotherm. SST cooling under the storm core (0.4°C) produced a 16% decrease in air-sea heat flux implying an approximately 5 ms-1 reduction in peak winds

  16. Deaths associated with Hurricane Sandy - October-November 2012.

    Science.gov (United States)

    2013-05-24

    On October 29, 2012, Hurricane Sandy hit the northeastern U.S. coastline. Sandy's tropical storm winds stretched over 900 miles (1,440 km), causing storm surges and destruction over a larger area than that affected by hurricanes with more intensity but narrower paths. Based on storm surge predictions, mandatory evacuations were ordered on October 28, including for New York City's Evacuation Zone A, the coastal zone at risk for flooding from any hurricane. By October 31, the region had 6-12 inches (15-30 cm) of precipitation, 7-8 million customers without power, approximately 20,000 persons in shelters, and news reports of numerous fatalities (Robert Neurath, CDC, personal communication, 2013). To characterize deaths related to Sandy, CDC analyzed data on 117 hurricane-related deaths captured by American Red Cross (Red Cross) mortality tracking during October 28-November 30, 2012. This report describes the results of that analysis, which found drowning was the most common cause of death related to Sandy, and 45% of drowning deaths occurred in flooded homes in Evacuation Zone A. Drowning is a leading cause of hurricane death but is preventable with advance warning systems and evacuation plans. Emergency plans should ensure that persons receive and comprehend evacuation messages and have the necessary resources to comply with them.

  17. Thermal Modeling and Analysis of the Hurricane Imaging Radiometer (HIRad)

    Science.gov (United States)

    Mauro, Stephanie

    2013-01-01

    The Hurricane Imaging Radiometer (HIRad) is a payload carried by an unmanned aerial vehicle (UAV) at altitudes up to 60,000 ft with the purpose of measuring ocean surface wind speeds and near ocean surface rain rates in hurricanes. The payload includes several components that must maintain steady temperatures throughout the flight. Minimizing the temperature drift of these components allows for accurate data collection and conclusions to be drawn concerning the behavior of hurricanes. HIRad has flown on several different UAVs over the past two years during the fall hurricane season. Based on the data from the 2011 flight, a Thermal Desktop model was created to simulate the payload and reproduce the temperatures. Using this model, recommendations were made to reduce the temperature drift through the use of heaters controlled by resistance temperature detector (RTD) sensors. The suggestions made were implemented for the 2012 hurricane season and further data was collected. The implementation of the heaters reduced the temperature drift for a portion of the flight, but after a period of time, the temperatures rose. With this new flight data, the thermal model was updated and correlated. Detailed analysis was conducted to determine a more effective way to reduce the temperature drift. The final recommendations made were to adjust the set temperatures of the heaters for 2013 flights and implement hardware changes for flights beyond 2013.

  18. Hurricane Loss Analysis Based on the Population-Weighted Index

    Directory of Open Access Journals (Sweden)

    Grzegorz Kakareko

    2017-08-01

    Full Text Available This paper discusses different measures for quantifying regional hurricane loss. The main measures used in the past are normalized percentage loss and dollar value loss. In this research, we show that these measures are useful but may not properly reflect the size of the population influenced by hurricanes. A new loss measure is proposed that reflects the hurricane impact on people occupying the structure. For demonstrating the differences among these metrics, regional loss analysis was conducted for Florida. The regional analysis was composed of three modules: the hazard module stochastically modeled the wind occurrence in the region; the vulnerability module utilized vulnerability functions developed in this research to calculate the loss; and the financial module quantified the hurricane loss. In the financial module, we calculated three loss metrics for certain region. The first metric is the average annual loss (AAL which represents the expected loss per year in percentage. The second is the average annual dollar loss which represents the expected dollar amount loss per year. The third is the average annual population-weighted loss (AAPL—a new measure proposed in this research. Compared with the AAL, the AAPL reflects the number of people influenced by the hurricane. The advantages of the AAPL are illustrated using three different analysis examples: (1 conventional regional loss analysis, (2 mitigation potential analysis, and (3 forecasted future loss analysis due to the change in population.

  19. Analysis of High Temporal and Spatial Observations of Hurricane Joaquin During TCI-15

    Science.gov (United States)

    Creasey, Robert; Elsberry, Russell L.; Velden, Chris; Cecil, Daniel J.; Bell, Michael; Hendricks, Eric A.

    2016-01-01

    Objectives: Provide an example of why analysis of high density soundings across Hurricane Joaquin also require highly accurate center positions; Describe technique for calculating 3-D zero-wind center positions from the highly accurate GPS positions of sequences of High-Density Sounding System (HDSS) soundings as they fall from 10 km to the ocean surface; Illustrate the vertical tilt of the vortex above 4-5 km during two center passes through Hurricane Joaquin on 4 October 2015.

  20. Hurricane Katrina as a "teachable moment"

    Science.gov (United States)

    Glantz, M. H.

    2008-04-01

    By American standards, New Orleans is a very old, very popular city in the southern part of the United States. It is located in Louisiana at the mouth of the Mississippi River, a river which drains about 40% of the Continental United States, making New Orleans a major port city. It is also located in an area of major oil reserves onshore, as well as offshore, in the Gulf of Mexico. Most people know New Orleans as a tourist hotspot; especially well-known is the Mardi Gras season at the beginning of Lent. People refer to the city as the "Big Easy". A recent biography of the city refers to it as the place where the emergence of modern tourism began. A multicultural city with a heavy French influence, it was part of the Louisiana Purchase from France in early 1803, when the United States bought it, doubling the size of the United States at that time. Today, in the year 2007, New Orleans is now known for the devastating impacts it withstood during the onslaught of Hurricane Katrina in late August 2005. Eighty percent of the city was submerged under flood waters. Almost two years have passed, and many individuals and government agencies are still coping with the hurricane's consequences. And insurance companies have been withdrawing their coverage for the region. The 2005 hurricane season set a record, in the sense that there were 28 named storms that calendar year. For the first time in hurricane forecast history, hurricane forecasters had to resort to the use of Greek letters to name tropical storms in the Atlantic and Gulf (Fig.~1). Hurricane Katrina was a Category 5 hurricane when it was in the middle of the Gulf of Mexico, after having passed across southern Florida. At landfall, Katrina's winds decreased in speed and it was relabeled as a Category 4. It devolved into a Category 3 hurricane as it passed inland when it did most of its damage. Large expanses of the city were inundated, many parts under water on the order of 20 feet or so. The Ninth Ward, heavily

  1. Hurricane Katrina as a "teachable moment"

    Directory of Open Access Journals (Sweden)

    M. H. Glantz

    2008-04-01

    Full Text Available By American standards, New Orleans is a very old, very popular city in the southern part of the United States. It is located in Louisiana at the mouth of the Mississippi River, a river which drains about 40% of the Continental United States, making New Orleans a major port city. It is also located in an area of major oil reserves onshore, as well as offshore, in the Gulf of Mexico. Most people know New Orleans as a tourist hotspot; especially well-known is the Mardi Gras season at the beginning of Lent. People refer to the city as the "Big Easy". A recent biography of the city refers to it as the place where the emergence of modern tourism began. A multicultural city with a heavy French influence, it was part of the Louisiana Purchase from France in early 1803, when the United States bought it, doubling the size of the United States at that time.

    Today, in the year 2007, New Orleans is now known for the devastating impacts it withstood during the onslaught of Hurricane Katrina in late August 2005. Eighty percent of the city was submerged under flood waters. Almost two years have passed, and many individuals and government agencies are still coping with the hurricane's consequences. And insurance companies have been withdrawing their coverage for the region.

    The 2005 hurricane season set a record, in the sense that there were 28 named storms that calendar year. For the first time in hurricane forecast history, hurricane forecasters had to resort to the use of Greek letters to name tropical storms in the Atlantic and Gulf (Fig.~1.

    Hurricane Katrina was a Category 5 hurricane when it was in the middle of the Gulf of Mexico, after having passed across southern Florida. At landfall, Katrina's winds decreased in speed and it was relabeled as a Category 4. It devolved into a Category 3 hurricane as it passed inland when it did most of its damage. Large expanses of the city were inundated, many parts under water on

  2. Examining Pacific and Atlantic Hurricane Stage Duration and Length Since 1980

    Science.gov (United States)

    Wachtel, C. J.; Godek, M. L.

    2015-12-01

    Examining Pacific and Atlantic Hurricane Stage Duration and Length Since 1980Cassidy Wachtel and Melissa L. GodekDepartment of Earth and Atmospheric Sciences, State University of New York College at Oneonta, New York 13820 Abstract:Each year hurricanes impact thousands of people and over time changes in hurricane characteristics, such as intensity and frequency, have been identified. This study aims to examine changes in hurricane stage duration and track length of West Atlantic and eastern North Pacific hurricanes between 1980 and 2013. Category 2 through 5 hurricanes are analyzed as they evolved through the full life cycle of a hurricane (tropical depression to tropical storm to category). The NOAA National Ocean Service hurricane reanalysis datasets are used to identify 286 storms which are statistically analyzed by category for 1) temporal changes in stage duration with time and 2) temporal changes in stage track lengths with time. NOAA Earth System Research Laboratory daily mean composites of variables such as vertical wind shear and sea surface temperatures are then examined to explain the temporal tendencies that may be related to climate change. Preliminary results indicate that category 2, 4 and 5 storms experienced an overall decrease in stage duration since 1980. For storms of these magnitudes, generally more rapid intensification to category has occurred over time. Contrarily, increased stage duration is detected for hurricanes that reached category 3 status, showing that these storms have strengthened more slowly with time. In all categories, a few unique cases occurred that exhibited stage durations greater than 1 standard deviation from the mean of the long term trend. These cases require further scrutiny for the environmental conditions that might explain the anomalous departures. Keywords: Hurricanes, West Atlantic Ocean, North Pacific Ocean, Storm Tracks, Tropical Storm, Tropical Depression, Hurricane Stage

  3. Assessment of Sea Surface Temperatures in the Caribbean Sea Associated with Hurricane Tracks Using GOES-East Infrared Measurement

    Science.gov (United States)

    Comeaux, J. C.; Walker, N. D.; Haag, A.; Pino, J. V.

    2016-02-01

    A minimum sea surface temperature (SST) of 26° C is considered a requirement for hurricane generation and maintenance. Although the Caribbean Sea lies within the Western Hemisphere Warm Pool, notable north-south gradients in SST during summer often exist due to wind-induced cool water upwelling along the northern coast of South America. Our hypothesis is that the spatial extent and magnitude of cooling due to this upwelling process has an impact on the location of individual hurricane tracks. We propose that hurricanes will track further north when upwelling is strong and regionally extensive. We will investigate spatial SST variability within and across hurricane seasons in relationship to hurricane tracks. We will also investigate SST along the hurricane tracks. SSTs will be quantified using GOES-East weekly and monthly composites at a spatial resolution of 4x4 km and using the 4 micron channel, which is least affected by atmospheric water vapor attenuation.A minimum sea surface temperature (SST) of 26° C is considered a requirement for hurricane generation and maintenance. Although the Caribbean Sea lies within the Western Hemisphere Warm Pool, notable north-south gradients in SST during summer often exist due to wind-induced cool water upwelling along the northern coast of South America. Our hypothesis is that the spatial extent and magnitude of cooling due to this upwelling process has an impact on the location of individual hurricane tracks. We propose that hurricanes will track further north when upwelling is strong and regionally extensive. We will investigate spatial SST variability within and across hurricane seasons in relationship to hurricane tracks. We will also investigate SST along the hurricane tracks. SSTs will be quantified using GOES-East weekly and monthly composites at a spatial resolution of 4x4 km and using the 4 micron channel, which is least affected by atmospheric water vapor attenuation.

  4. How Hurricanes Get Their Names

    Institute of Scientific and Technical Information of China (English)

    张梅荐

    2000-01-01

    The first people who gave names to hurricanes were those who knew them best the people of Puerto Rico. The small island of Puerto Rico is in the West Indies, off the coast of Florida. This is where all the hurricanes begin that strike the east coast of the United States.

  5. 76 FR 63541 - Design-Basis Hurricane and Hurricane Missiles for Nuclear Power Plants

    Science.gov (United States)

    2011-10-13

    ...-2010-0288] Design-Basis Hurricane and Hurricane Missiles for Nuclear Power Plants AGENCY: Nuclear... Hurricane Missiles for Nuclear Power Plants.'' This regulatory guide provides licensees and applicants with... hurricane and design-basis hurricane-generated missiles that a nuclear power plant should be designed...

  6. Controlling a hurricane by altering its internal climate

    Science.gov (United States)

    Mardhekar, D.

    2010-09-01

    Atmospheric hazards, like the fury of a hurricane, can be controlled by altering its internal climate. The hurricane controlling technique suggested is eco-friendly, compatible with hurricane size, has a sound scientific base and is practically possible. The key factor is a large scale dilution of the hurricane fuel, vapour, in the eye wall and spiral rain bands where condensation causing vapor volume reduction (a new concept which can be explained by Avogadro's law) and latent heat release drive the storm. This can be achieved by installing multiple storage tanks containing dry liquefied air on the onshore and offshore coastal regions and islands, preferably underground, in the usual path of a hurricane. Each storage tank is designed to hold and release dry liquefied air of around 100,000 tons. Satellite tracking of hurricanes can locate the eye wall and the spiral rain bands. The installed storage tanks coming under these areas will rapidly inject dry air in huge quantities thereby diluting the vapour content of the vapour-rich air in the eye wall and in the spiral rain bands. This will result in reduced natural input of vapour-rich air, reduced release of latent heat, reduced formation of the low pressure zone due to condensation and volume reduction of the vapor, expansion of the artificially introduced dry air as it goes up occupying a larger space with the diluted fuel, absorption of energy from the system by low temperature of the artificially introduced air. It will effect considerable condensation of the vapor near the sea surface thus further starving the hurricane of its fuel in its engine. Seeding materials, or microscopic dust as suggested by Dr. Daniel Rosenfeld in large quantities may also be introduced via the flow of the injected dry air in order to enhance the hurricane controlling ability. All the above factors are in favour of retarding the hurricane's wind speed and power. The sudden weakening of hurricane Lili was found to be partially caused

  7. EarthLabs - Investigating Hurricanes: Earth's Meteorological Monsters

    Science.gov (United States)

    McDaris, J. R.; Dahlman, L.; Barstow, D.

    2007-12-01

    Earth science is one of the most important tools that the global community needs to address the pressing environmental, social, and economic issues of our time. While, at times considered a second-rate science at the high school level, it is currently undergoing a major revolution in the depth of content and pedagogical vitality. As part of this revolution, labs in Earth science courses need to shift their focus from cookbook-like activities with known outcomes to open-ended investigations that challenge students to think, explore and apply their learning. We need to establish a new model for Earth science as a rigorous lab science in policy, perception, and reality. As a concerted response to this need, five states, a coalition of scientists and educators, and an experienced curriculum team are creating a national model for a lab-based high school Earth science course named EarthLabs. This lab course will comply with the National Science Education Standards as well as the states' curriculum frameworks. The content will focus on Earth system science and environmental literacy. The lab experiences will feature a combination of field work, classroom experiments, and computer access to data and visualizations, and demonstrate the rigor and depth of a true lab course. The effort is being funded by NOAA's Environmental Literacy program. One of the prototype units of the course is Investigating Hurricanes. Hurricanes are phenomena which have tremendous impact on humanity and the resources we use. They are also the result of complex interacting Earth systems, making them perfect objects for rigorous investigation of many concepts commonly covered in Earth science courses, such as meteorology, climate, and global wind circulation. Students are able to use the same data sets, analysis tools, and research techniques that scientists employ in their research, yielding truly authentic learning opportunities. This month-long integrated unit uses hurricanes as the story line by

  8. Hurricane Risk Variability along the Gulf of Mexico Coastline

    OpenAIRE

    Jill C Trepanier; Ellis, Kelsey N.; Clay S Tucker

    2015-01-01

    Hurricane risk characteristics are examined across the U. S. Gulf of Mexico coastline using a hexagonal tessellation. Using an extreme value model, parameters are collected representing the rate or λ (frequency), the scale or σ (range), and the shape or ξ (intensity) of the extreme wind distribution. These latent parameters and the 30-year return level are visualized across the grid. The greatest 30-year return levels are located toward the center of the Gulf of Mexico, and for inland locatio...

  9. Large contribution of sea surface warming to recent increase in Atlantic hurricane activity.

    Science.gov (United States)

    Saunders, Mark A; Lea, Adam S

    2008-01-31

    Atlantic hurricane activity has increased significantly since 1995 (refs 1-4), but the underlying causes of this increase remain uncertain. It is widely thought that rising Atlantic sea surface temperatures have had a role in this, but the magnitude of this contribution is not known. Here we quantify this contribution for storms that formed in the tropical North Atlantic, Caribbean Sea and Gulf of Mexico; these regions together account for most of the hurricanes that make landfall in the United States. We show that a statistical model based on two environmental variables--local sea surface temperature and an atmospheric wind field--can replicate a large proportion of the variance in tropical Atlantic hurricane frequency and activity between 1965 and 2005. We then remove the influence of the atmospheric wind field to assess the contribution of sea surface temperature. Our results indicate that the sensitivity of tropical Atlantic hurricane activity to August-September sea surface temperature over the period we consider is such that a 0.5 degrees C increase in sea surface temperature is associated with a approximately 40% increase in hurricane frequency and activity. The results also indicate that local sea surface warming was responsible for approximately 40% of the increase in hurricane activity relative to the 1950-2000 average between 1996 and 2005. Our analysis does not identify whether warming induced by greenhouse gases contributed to the increase in hurricane activity, but the ability of climate models to reproduce the observed relationship between hurricanes and sea surface temperature will serve as a useful means of assessing whether they are likely to provide reliable projections of future changes in Atlantic hurricane activity.

  10. The effects of hurricanes on birds, with special reference to Caribbean islands

    Science.gov (United States)

    Wiley, J.W.; Wunderle, J.M.

    1993-01-01

    Cyclonic storms, variously called typhoons, cyclones, or hurricanes (henceforth, hurricanes), are common in many parts of the world, where their frequent occurrence can have both direct and indirect effects on bird populations. Direct effects of hurricanes include mortality from exposure to hurricane winds, rains, and storm surges, and geographic displacement of individuals by storm winds. Indirect effects become apparent in the storm's aftermath and include loss of food supplies or foraging substrates; loss of nests and nest or roost sites; increased vulnerability to predation; microclimate changes; and increased conflict with humans. The short-term response of bird populations to hurricane damage, before changes in plant succession, includes shifts in diet, foraging sites or habitats, and reproductive changes. Bird populations may show long-term responses to changes in plant succession as second-growth vegetation increases in storm-damaged old-growth forests. The greatest stress of a hurricane to most upland terrestrial bird populations occurs after its passage rather than during its impact. The most important effect of a hurricane is the destruction of vegetation, which secondarily affects wildlife in the storm's aftermath. The most vulnerable terrestrial wildlife populations have a diet of nectar, fruit, or seeds; nest, roost, or forage on large old trees; require a closed forest canopy; have special microclimate requirements and/or live in a habitat in which vegetation has a slow recovery rate. Small populations with these traits are at greatest risk to hurricane-induced extinction, particularly if they exist in small isolated habitat fragments. Recovery of avian populations from hurricane effects is partially dependent on the extent and degree of vegetation damage as well as its rate of recovery. Also, the reproductive rate of the remnant local population and recruitment from undisturbed habitat patches influence the rate at which wildlife populations recover

  11. Multimedia Retrieval

    NARCIS (Netherlands)

    Blanken, H.M.; Vries, de A.P.; Blok, H.E.; Feng, L.

    2007-01-01

    Retrieval of multimedia data is different from retrieval of structured data. A key problem in multimedia databases is search, and the proposed solutions to the problem of multimedia information retrieval span a rather wide spectrum of topics outside the traditional database area, ranging from inform

  12. Assessing a 1500-year record of Atlantic hurricane activity from South Andros Island, the Bahamas, using modeled hurricane climatology

    Science.gov (United States)

    Wallace, E. J.; Donnelly, J. P.; Emanuel, K.; Wiman, C.; van Hengstum, P. J.; Sullivan, R.; Winkler, T. S.

    2016-12-01

    Tropical cyclones can cause substantial loss of life and economic resources in coastal areas. In the current changing climate, it is of critical importance for society to understand any links between hurricane activity and climactic conditions. Unfortunately, historical tropical cyclone records are too short and incomplete to constrain how climate controls cyclone activity or to accurately quantify the risk of such storms to local human populations. Hurricane-induced deposits preserved in sediment cores can offer records of past hurricane activity stretching over thousands of years. Here we present a 1500 year annually resolved record of the frequency of intense hurricane events in a blue hole (AM4) on South Andros Island on the Great Bahama Bank. This carbonate island in the western North Atlantic Ocean is positioned along the trackway of many storms originating in the Caribbean and Atlantic basins. The record is corroborated by cores collected from three other blue holes near AM4. Over the past 1500 years, there have been periods of elevated hurricane activity from 750 to 950 CE, 1150 to 1300 CE and 1550 to 1850 CE. The statistical significance of this sedimentary record is assessed utilizing a set of synthetic storms generated from a previously published statistical deterministic hurricane model. The model simulates climatological conditions from the NCEP/NCAR reanalysis dataset, and the CMIP5 MPI model for the 20th century calibration (1850-2005 CE), and the millennial simulation (850-1849 CE). The average reoccurrence rates of hurricanes passing within 100 km of AM4 under each simulation are 1.06, 0.62, and 0.61 storms per year respectively. Using each climatology, thousands of hurricane induced deposits for the site are generated based on a random draw of these storms, a wind speed threshold for deposit, and a temporal resolution given the sedimentation rate of approximately 1 cm/yr at the site. Overall, the results of this study offer information on changes

  13. Hazardous substances releases associated with Hurricanes Katrina and Rita in industrial settings, Louisiana and Texas.

    Science.gov (United States)

    Ruckart, Perri Zeitz; Orr, Maureen F; Lanier, Kenneth; Koehler, Allison

    2008-11-15

    The scientific literature concerning the public health response to the unprecedented hurricanes striking the Gulf Coast in August and September 2005 has focused mainly on assessing health-related needs and surveillance of injuries, infectious diseases, and other illnesses. However, the hurricanes also resulted in unintended hazardous substances releases in the affected states. Data from two states (Louisiana and Texas) participating in the Hazardous Substances Emergency Events Surveillance (HSEES) system were analyzed to describe the characteristics of hazardous substances releases in industrial settings associated with Hurricanes Katrina and Rita. HSEES is an active multi-state Web-based surveillance system maintained by the Agency for Toxic Substances and Disease Registry (ATSDR). In 2005, 166 hurricane-related hazardous substances events in industrial settings in Louisiana and Texas were reported. Most (72.3%) releases were due to emergency shut downs in preparation for the hurricanes and start-ups after the hurricanes. Emphasis is given to the contributing causal factors, hazardous substances released, and event scenarios. Recommendations are made to prevent or minimize acute releases of hazardous substances during future hurricanes, including installing backup power generation, securing equipment and piping to withstand high winds, establishing procedures to shutdown process operations safely, following established and up-to-date start-up procedures and checklists, and carefully performing pre-start-up safety reviews.

  14. Hurricane Katrina-induced forest damage in relation to ecological factors at landscape scale.

    Science.gov (United States)

    Wang, Fugui; Xu, Y Jun

    2009-09-01

    Forest stand stability to strong winds such as hurricanes has been found to be associated with a number of forest, soil and topography factors. In this study, through applying geographic information system (GIS) and logit regression, we assessed effects of forest characteristics and site conditions on pattern, severity and probability of Hurricane Katrina disturbance to forests in the Lower Pearl River Valley, USA. The factors included forest type, forest coverage, stand density, soil great group, elevation, slope, aspect, and stream buffer zone. Results showed that Hurricane Katrina damaged 60% of the total forested land in the region. The distribution and intensity of the hurricane disturbance varied across the landscape, with the bottomland hardwood forests on river floodplains most severely affected. All these factors had a variety of effects on vulnerability of the forests to the hurricane disturbance and thereby spatial patterns of the disturbance. Soil groups and stand factors including forest types, forest coverage and stand density contributed to 85% of accuracy in modeling the probability of the hurricane disturbance to forests in this region. Besides assessment of Katrina's damage, this study elucidates the great usefulness of remote sensing and GIS techniques combined with statistics modeling in assessment of large-scale risks of hurricane damage to coastal forests.

  15. Household Adjustments to Hurricane Katrina

    National Research Council Canada - National Science Library

    Meri Davlasheridze; Qin Fan

    2017-01-01

    This paper examines household adjustments to Hurricane Katrina by estimating the effects of Katrina-induced damages on changes in household demographics and income distributions in the Orleans Parish...

  16. Climate change: Unattributed hurricane damage

    Science.gov (United States)

    Hallegatte, Stéphane

    2015-11-01

    In the United States, hurricanes have been causing more and more economic damage. A reanalysis of the disaster database using a statistical method that accounts for improvements in resilience opens the possibility that climate change has played a role.

  17. The Conservation of Helicity in Hurricane Andrew (1992) and the Formation of the Spiral Rainband

    Institute of Scientific and Technical Information of China (English)

    徐亚梅; 伍荣生

    2003-01-01

    The characteristics of helicity in a hurricane are presented by calculating the MM5 model output in addition to theoretical analysis. It is found that helicity in a hurricane mainly depends on its horizontal component, whose magnitude is about 100 to 1000 times larger than its vertical component. It is also found that helicity is approximately conserved in the hurricane. Since the fluid has the intention to adjust the wind shear to satisfy the conservation of helicity, the horizontal vorticity is even larger than the vertical vorticity, and the three-dimensional vortices slant to the horizontal plane except in the inner eye. There are significant horizontal vortices and inhomogeneous helical flows in the hurricane. The formation of the spiral rainband is discussed by using the law of horizontal helical flows. It is closely related to the horizontal strong vortices and inhomogeneous helical flows.

  18. The Hurricane and Its Impact

    Science.gov (United States)

    Burpee, Robert W.

    Recent population increases in coastal regions of the tropics and subtropics have greatly enhanced man's vulnerability to tropical cyclones. Thus, this book on hurricanes by Robert H. Simpson and Herbert Riehl, two of the leading contributors to hurricane research during the last 35 years, comes along when people of differing backgrounds want to learn more about hurricanes. In the 20 years since Dunn and Miller published Atlantic Hurricanes, technical advances in weather satellites, computer modeling and data processing, and research aircraft have substantially increased the tropical meteorologist's understanding of hurricane structure and dynamics. During this same time, field experiments have led to detailed knowledge of the atmospheric environment within which tropical cyclones are initiated. The authors have attempted to describe many aspects of hurricanes for readers that range from students of meteorology to those concerned with planning for natural hazards in the coastal zone. Because Simpson and Riehl have addressed such a wide audience, many readers with a knowledge of atmospheric science will find that the book is overly descriptive, while readers without some background in physics will find it is too technical.

  19. Effect of hurricane paths on storm surge response at Tianjin, China

    Science.gov (United States)

    Feng, Xingru; Yin, Baoshu; Yang, Dezhou

    2012-06-01

    A hurricane induced storm surge simulation system was developed for Tianjin coast, which consists of a hurricane model and a storm surge model. The peak storm surge result of the simulation agreed well with that of the observation. Three observed paths (Rita, Mimie and WINNIE) and a hypothetical path (Rita2) were chosen as the selective hurricane paths according to their positions relative to Tianjin. The sensitivity of Tianjin storm surge to the four paths was investigated using the validated storm surge simulation system. Three groups of experiments were done. In group one, the models were forced by the wind field and air pressure; in group two and three the models were forced by the wind only and the air pressure only respectively. In the experiments, the hurricane moved with a fixed speed and an intensity of 50 year return period. The simulation results show that path of the type Rita2 is the easiest to cause storm surge disaster in Tianjin, and the effect of air pressure forcing is most evident for path of the type Rita in Tianjin storm surge process. The above conclusions were analyzed through the evolution of the wind fields and the air pressure distributions. Comparing the experiment results of Group one, two and three, it can be seen that the storm surge is mainly induced by the wind forcing and the nonlinear interaction between the effect of wind forcing and air pressure forcing on the storm surge tends to weaken the storm surge.

  20. 非线性VAD反演低层风廓线拟合阶数优化方法%Optimization of Nonlinear VAD Method in the Low-level Wind Retrieval

    Institute of Scientific and Technical Information of China (English)

    马秀梅; 李文兆; 赵坤; 唐晓文; 杨洪平

    2014-01-01

    The performance of nonlinear velocity azimuth display method in the vertical wind profile retrieval at low levels (below 2 km)is quantitatively examined by combing the theoretical analysis and cases observed by SoWMEX S-Pol radar and Yangjiang radar in Guangdong Province.Results show that the general structure and evolution of the low-level wind profile can be reasonably deduced by traditional nonlinear VAD method.The root mean square error can be used to evaluate orders of velocity azimuth display (VAD)fitting,but small error does not always mean the better performance especially with big continuous data absence,and a specific example is given.When setting the VAD fitting order to 3 instead of 2 ,coeffi-cients which represent the horizontal wind u and v are closer to the wind derived from radial velocity im-age.However,when the fitting order comes to 4,coefficients lost their physical meaning.The wind direc-tion differs a lot and the speed is much smaller than the value before.At the same time,the root mean square error decreases compared with the order of 3 .Besides,data used in nonlinear VAD fitting come from the whole volume,which decreases quite a lot and leads to nonlinear VAD fitting error when the vol-ume coverage pattern (VCP)only has some lower elevations (e.g.,two elevations).Therefore,the re-trieved wind could contain large error in certain situations,such as for a region with large continuous data absence or a volume scan with fewer elevations. After carefully evaluating the impact of the corresponding parameters on the nonlinear VAD retrievals by analyzing radar measurements,a modified nonlinear VAD method is proposed which takes account of the maximum fitting order in horizontal (VAD)and vertical adaptively according to the size of continuous data absence and the number of sweeps in a volume scan.VAD fitting is abandoned when the data absence is larger than 90°;the order is set to 3 when the data absence is between 60°and 90°;and the order is set

  1. Determining Key Model Parameters of Rapidly Intensifying Hurricane Guillermo(1997) using the Ensemble Kalman Filter

    CERN Document Server

    Godinez, Humberto C; Fierro, Alexandre O; Guimond, Stephen R; Kao, Jim

    2011-01-01

    In this work we present the assimilation of dual-Doppler radar observations for rapidly intensifying hurricane Guillermo (1997) using the Ensemble Kalman Filter (EnKF) to determine key model parameters. A unique aspect of Guillermo was that during the period of radar observations strong convective bursts, attributable to wind shear, formed primarily within the eastern semicircle of the eyewall. To reproduce this observed structure within a hurricane model, background wind shear of some magnitude must be specified; as well as turbulence and surface parameters appropriately specified so that the impact of the shear on the simulated hurricane vortex can be realized. To first illustrate the complex nonlinear interactions induced by changes in these parameters, an ensemble of 120 simulations have been conducted in which individual members were formulated by sampling the parameters within a certain range via a Latin hypercube approach. Next, data from the 120 simulations and two distinct derived fields of observati...

  2. Further Exploring the Potential for Assimilation of Unmanned Aircraft Observations to Benefit Hurricane Analyses and Forecasts

    Science.gov (United States)

    Sippel, Jason A.; Zhang, Fuqing; Weng, Yonghui; Braun, Scott A.; Cecil, Daniel J.

    2015-01-01

    This study explores the potential of assimilating data from multiple instruments onboard high-altitude, long-endurance unmanned aircraft to improve hurricane analyses and forecasts. A recent study found a significant positive impact on analyses and forecasts of Hurricane Karl when an ensemble Kalman filter was used to assimilate data from the High-altitude Imaging Wind and Rain Airborne Profiler (HIWRAP), a new Doppler radar onboard the NASA Global Hawk (GH) unmanned airborne system. The GH can also carry other useful instruments, including dropsondes and the Hurricane Imaging Radiometer (HIRAD), which is a new radiometer that estimates large swaths of wind speeds and rainfall at the ocean surface. The primary finding is that simultaneously assimilating data from HIWRAP and the other GH-compatible instruments results in further analysis and forecast improvement for Karl. The greatest improvement comes when HIWRAP, HIRAD, and dropsonde data are simultaneously assimilated.

  3. Effect of Hurricane Andrew on the Turkey Point Nuclear Generating Station from August 20--30, 1992. [Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hebdon, F.J. [Institute of Nuclear Power Operations, Atlanta, GA (United States)

    1993-03-01

    On August 24, 1992, Hurricane Andrew, a Category 4 hurricane, struck the Turkey Point Electrical Generating Station with sustained winds of 145 mph (233 km/h). This is the report of the team that the US Nuclear Regulatory Commission (NRC) and the Institute of Nuclear Power Operations (INPO) jointly sponsored (1) to review the damage that the hurricane caused the nuclear units and the utility`s actions to prepare for the storm and recover from it, and (2) to compile lessons that might benefit other nuclear reactor facilities.

  4. Hurricane Wilma Poster (October 24, 2005)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hurricane Wilma poster. Multi-spectral image from NOAA-18 shows Hurricane Wilma exiting Florida off the east Florida coast on October 24, 2005. Poster size is 34"x30".

  5. Hurricane Hugo Poster (September 21, 1989)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hurricane Hugo poster. Multi-spectral image from NOAA-11 captures Hurricane Hugo slamming into South Carolina coast on September 21, 1989. Poster size is 36"x36".

  6. Hurricane Sandy Poster (October 29, 2012)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hurricane Sandy poster. Multi-spectral image from Suomi-NPP shows Hurricane Sandy approaching the New Jersey Coast on October 29, 2012. Poster size is approximately...

  7. Hurricane Jeanne Poster (September 25, 2004)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hurricane Jeanne poster. Multi-spectral image from NOAA-16 shows Hurricane Jeanne near Grand Bahama Island on September 25, 2004. Poster size is 34"x30".

  8. Hurricane Charley Poster (August 13, 2004)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hurricane Charley poster. Multi-spectral image from NOAA-17 shows a small but powerful hurricane heading toward southern Florida on August 13, 2004. Poster dimension...

  9. Hurricane Isabel Poster (September 18, 2003)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hurricane Isabel poster. Multi-spectral image from NOAA-17 shows Hurricane Isabel making landfall on the North Carolina Outer Banks on September 18, 2003. Poster...

  10. Hurricane Frances Poster (September 5, 2004)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hurricane Frances poster. Multi-spectral image from NOAA-17 shows Hurricane Frances over central Florida on September 5, 2004. Poster dimension is approximately...

  11. Hurricane Ivan Poster (September 15, 2004)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hurricane Ivan poster. Multi-spectral image from NOAA-16 shows Hurricane Ivan in the Gulf of Mexico on September 15, 2004. Poster size is 34"x30".

  12. Effects of Hurricane Georges on habitat use by captive-reared Hispaniolan Parrots (Amazona ventralis) released in the Dominican Republic

    Science.gov (United States)

    White, T.H.; Collazo, J.A.; Vilella, F.J.; Guerrero, S.A.

    2005-01-01

    We radio-tagged and released 49 captive-reared Hispaniolan Parrots (Amazona ventralis) in Parque Nacional del Este (PNE), Dominican Republic, during 1997 and 1998. Our primary objective was to develop a restoration program centered on using aviary-reared birds to further the recovery of the critically endangered Puerto Rican Parrot (A. vittata). Hurricane Georges made landfall over the release area on 22 September 1998 with sustained winds of 224 km/h, providing us with a unique opportunity to quantify responses of parrots to such disturbances. Quantitative data on such responses by any avian species are scarce, particularly for Amazona species, many of which are in peril and occur in hurricane-prone areas throughout the Caribbean. Mean home ranges of 18 parrots monitored both before and after the hurricane increased (P = 0.08) from 864 ha (CI = 689-1039 ha) pre-hurricane to 1690 ha (CI = 1003-2377 ha) post-hurricane. The total area traversed by all parrots increased > 300%, from 4884 ha pre-hurricane to 15,490 ha post-hurricane. Before Hurricane Georges, parrot activity was concentrated in coastal scrub, tall broadleaf forest, and abandoned agriculture (conucos). After the hurricane, parrots concentrated their activities in areas of tall broadleaf forest and abandoned conucos. Topographic relief, primarily in the form of large sinkholes, resulted in "resource refugia" where parrots and other frugivores foraged after the hurricane. Habitat use and movement patterns exhibited by released birds highlight the importance of carefully considering effects of season, topography, and overall size of release areas when planning psittacine restorations in hurricane-prone areas. ?? The Neotropical Ornithological Society.

  13. Use of Windbreaks for Hurricane Protection of Critical Facilities

    Science.gov (United States)

    Hyater-Adams, Sinone; DeYoung, Russell J.

    2012-01-01

    The protection of NASA Langley Research Center from future hurricanes is important in order to allow the center to fulfill its mission. The impact of the center is not only great within NASA but the economy as well. The infrastructure of the Center is under potential risk in the future because of more intense hurricanes with higher speed winds and flooding. A potential method of protecting the Center s facilities is the placement of a windbreak barrier composed of indigenous trees. The New Town program that is now in progress creates a more condensed area of focus for protection. A potential design for an efficient tree windbreak barrier for Langley Research center is proposed.

  14. Retrieved Products from Simulated Hyperspectral Observations of a Hurricane

    Science.gov (United States)

    Susskind, Joel; Kouvaris, Louis; Iredell, Lena; Blaisdell, John

    2015-01-01

    Demonstrate via Observing System Simulation Experiments (OSSEs) the potential utility of flying high spatial resolution AIRS class IR sounders on future LEO and GEO missions.The study simulates and analyzes radiances for 3 sounders with AIRS spectral and radiometric properties on different orbits with different spatial resolutions: 1) Control run 13 kilometers AIRS spatial resolution at nadir on LEO in Aqua orbit; 2) 2 kilometer spatial resolution LEO sounder at nadir ARIES; 3) 5 kilometers spatial resolution sounder on a GEO orbit, radiances simulated every 72 minutes.

  15. Forecasting Hurricane by Satellite Image

    Science.gov (United States)

    Liu, M. Y.

    Earth is an endanger planet. Severe weather, especially hurricanes, results in great disaster all the world. World Meteorology Organization and United Nations Environment Program established intergovernment Panel on Climate Change (IPCC) to offer warnings about the present and future disasters of the Earth. It is the mission for scientists to design warning system to predict the severe weather system and to reduce the damage of the Earth. Hurricanes invade all the world every year and made millions damage to all the people. Scientists in weather service applied satellite images and synoptic data to forecast the information for the next hours for warning purposes. Regularly, hurricane hits on Taiwan island directly will pass through her domain and neighbor within 10 hours. In this study, we are going to demonstrate a tricky hurricane NARI invaded Taiwan on September 16, 2000. She wandered in the neighborhood of the island more than 72 hours and brought heavy rainfall over the island. Her track is so tricky that scientists can not forecast her path using the regular method. Fortunately, all scientists in the Central Weather Bureau paid their best effort to fight against the tricky hurricane. Applying the new developed technique to analysis the satellite images with synoptic data and radar echo, scientists forecasted the track, intensity and rainfall excellently. Thus the damage of the severe weather reduced significantly.

  16. Atlantic hurricane response to geoengineering

    Science.gov (United States)

    Moore, John; Grinsted, Aslak; Ji, Duoying; Yu, Xiaoyong; Guo, Xiaoran

    2015-04-01

    Devastating Atlantic hurricanes are relatively rare events. However their intensity and frequency in a warming world may rapidly increase - perhaps by a factor of 5 for a 2°C mean global warming. Geoengineering by sulphate aerosol injection preferentially cools the tropics relative to the polar regions, including the hurricane main development region in the Atlantic, suggesting that geoengineering may be an effective method of controlling hurricanes. We examine this hypothesis using 6 Earth System Model simulations of climate under the GeoMIP G3 and G4 schemes that use aerosols to reduce the radiative forcing under the RCP4.5 scenario. We find that although temperatures are ameliorated by geoengineering, the numbers of storm surge events as big as that caused the 2005 Katrina hurricane are only slightly reduced compared with no geoengineering. As higher levels of sulphate aerosol injection produce diminishing returns in terms of cooling, but cause undesirable effects in various regions, it seems that stratospheric aerosol geoengineering is not an effective method of controlling hurricane damage.

  17. Insights into Tornadoes and Hurricanes from High-Resolution Numerical Simulations

    Science.gov (United States)

    Bryan, G. H.; Cione, J.; Dahl, N.; Kalina, E.; Lundquist, J. K.; Nolan, D. S.; Rotunno, R.; Stern, D. P.; Worsnop, R.

    2016-12-01

    Comprehensive measurements of wind speed in tornadoes and hurricanes are rare because these phenomena are infrequent, turbulent, and (of course) very hazardous. However, detailed knowledge of the distribution of winds would be useful for a variety of applications such as structural engineering, societal awareness, and weather forecasting. To help fill in gaps in this knowledge, numerical model simulations can play a crucial role. The NCAR Yellowstone supercomputer has been used to conduct idealized simulations of tornadoes and hurricanes with grid spacing as small as 1 m. The simulations provide insight into the maximum wind speeds that may be possible in nature and provide guidance for interpreting present-day and future observational platforms. To this end, we have built code into a numerical model to produce "mock" observational datasets from hypothetical airplanes, dropsondes, and instrumented towers. Results are currently being used to help design offshore wind turbines, evaluate tornado intercept strategies, and develop flight paths for unmanned aerial systems.

  18. Year-ahead prediction of US landfalling hurricane numbers: intense hurricanes

    OpenAIRE

    Khare, Shree; Jewson, Stephen

    2005-01-01

    We continue with our program to derive simple practical methods that can be used to predict the number of US landfalling hurricanes a year in advance. We repeat an earlier study, but for a slightly different definition landfalling hurricanes, and for intense hurricanes only. We find that the averaging lengths needed for optimal predictions of numbers of intense hurricanes are longer than those needed for optimal predictions of numbers of hurricanes of all strengths.

  19. 7 CFR 701.50 - 2005 hurricanes.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false 2005 hurricanes. 701.50 Section 701.50 Agriculture... ADMINISTERED UNDER THIS PART § 701.50 2005 hurricanes. In addition benefits elsewhere allowed by this part, claims related to calendar year 2005 hurricane losses may be allowed to the extent provided for in §§ 701...

  20. Hurricane Katrina impacts on Mississippi forests

    Science.gov (United States)

    Sonja N. Oswalt; Christopher Oswalt; Jeffery Turner

    2008-01-01

    Hurricane Katrina triggered public interest and concern for forests in Mississippi that required rapid responses from the scientific community. A uniform systematic sample of 3,590 ground plots were established and measured in 687 days immediately after the impact of Hurricane Katrina on the Gulf Coast. The hurricane damaged an estimated 521 million trees with more...

  1. Hurricane Hazel: Canada's storm of the century

    National Research Council Canada - National Science Library

    Gifford, Jim

    2004-01-01

    ... For EleanorHurricane_Hazel_Interior.qxd 6/22/04 3:35 PM Page 3 HURRICANE HAZEL Canada's Storm of the Century Jim Gifford The dundurn Group Toronto * OxfordHurricane_Hazel_Interior.qxd 6/22/04 3:35...

  2. Hindcast and validation of Hurricane Ike waves, forerunner, and storm surge

    NARCIS (Netherlands)

    Hope, M.E.; Westerink, J.J.; Kennedy, A.B.; Kerr, P.C.; Dietrich, J.C.; Dawson, C.; Bender, C.J.; Smith, J.M.; Jensen, R.E.; Zijlema, M.; Holthuijsen, L.H.; Luettich, R.A.; Powell, M.D.; Cardone, V.J.; Cox, A.T.; Pourtaheri, H.; Roberts, H.J.; Atkinson, J.H.; Tanaka, S.; Westerink, H.J.; Westerink, L.G.

    2013-01-01

    Hurricane Ike (2008) made landfall near Galveston, Texas, as a moderate intensity storm. Its large wind field in conjunction with the Louisiana-Texas coastline's broad shelf and large scale concave geometry generated waves and surge that impacted over 1000 km of coastline. Ike's complex and varied w

  3. Hindcast and validation of Hurricane Ike waves, forerunner, and storm surge

    NARCIS (Netherlands)

    Hope, M.E.; Westerink, J.J.; Kennedy, A.B.; Kerr, P.C.; Dietrich, J.C.; Dawson, C.; Bender, C.J.; Smith, J.M.; Jensen, R.E.; Zijlema, M.; Holthuijsen, L.H.; Luettich, R.A.; Powell, M.D.; Cardone, V.J.; Cox, A.T.; Pourtaheri, H.; Roberts, H.J.; Atkinson, J.H.; Tanaka, S.; Westerink, H.J.; Westerink, L.G.

    2013-01-01

    Hurricane Ike (2008) made landfall near Galveston, Texas, as a moderate intensity storm. Its large wind field in conjunction with the Louisiana-Texas coastline's broad shelf and large scale concave geometry generated waves and surge that impacted over 1000 km of coastline. Ike's complex and varied w

  4. Hindcast and validation of Hurricane Ike waves, forerunner, and storm surge

    NARCIS (Netherlands)

    Hope, M.E.; Westerink, J.J.; Kennedy, A.B.; Kerr, P.C.; Dietrich, J.C.; Dawson, C.; Bender, C.J.; Smith, J.M.; Jensen, R.E.; Zijlema, M.; Holthuijsen, L.H.; Luettich, R.A.; Powell, M.D.; Cardone, V.J.; Cox, A.T.; Pourtaheri, H.; Roberts, H.J.; Atkinson, J.H.; Tanaka, S.; Westerink, H.J.; Westerink, L.G.

    2013-01-01

    Hurricane Ike (2008) made landfall near Galveston, Texas, as a moderate intensity storm. Its large wind field in conjunction with the Louisiana-Texas coastline's broad shelf and large scale concave geometry generated waves and surge that impacted over 1000 km of coastline. Ike's complex and varied

  5. A Universal Hurricane Frequency Function

    CERN Document Server

    Ehrlich, Robert

    2010-01-01

    Evidence is provided that the global distribution of tropical hurricanes is principally determined by a universal function H of a single variable z that in turn is expressible in terms of the local sea surface temperature and latitude. The data-driven model presented here carries stark implications for the large increased numbers of hurricanes which it predicts for a warmer world. Moreover, the rise in recent decades in the numbers of hurricanes in the Atlantic, but not the Pacific basin, is shown to have a simple explanation in terms of the specific form of H(z), which yields larger percentage increases when a fixed increase in sea surface temperature occurs at higher latitudes and lower temperatures.

  6. Delayed tree mortality in the Atchafalaya Basin of Southern Louisiana following Hurricane Andrew

    Science.gov (United States)

    Keeland, B.D.; Gorham, L.E.

    2009-01-01

    Hurricanes can damage trees in forested wetlands, and the potential for mortality related to these storms exists due to the effects of tree damage over time. In August 1992, Hurricane Andrew passed through the forested wetlands of southern Louisiana with winds in excess of 225 kph. Although more than 78 of the basal area was destroyed in some areas, most trees greater than 2.5 cm dbh were alive and resprouting prolifically the following year (98.8). Survival of most tree species was similarly high two years after the hurricane, but mortality rates of some species increased dramatically. For example, Populus heterophylla (swamp cottonwood) mortality increased from 7.8 to 59.2 (n 76) and Salix interior (sandbar willow) mortality increased from 4.5 to 57.1 (n 21). Stem sprouts on many up-rooted hardwood trees of other species were still alive in 1998, 6 years after the hurricane. Due to the understory tree species composition, regeneration, and high levels of resprouting, there was little change in species composition or perhaps a slight shift toward more shade and flood tolerant species six years following the hurricane event. Triadica sebifera (Chinese tallow) was found on some of the sites heavily disturbed by Hurricane Andrew, and may proliferate at the expense of native tree species. ?? 2009 The Society of Wetland Scientists.

  7. The dynamics of hurricane balls

    Science.gov (United States)

    Andersen, W. L.; Werner, Steven

    2015-09-01

    We examine the theory of the hurricane balls toy. This toy consists of two steel balls, welded together that are sent spinning on a horizontal surface somewhat like a top. Unlike a top, at high frequency the symmetry axis approaches a limiting inclination that is not perpendicular to the surface. We calculate (and experimentally verify) the limiting inclinations for three toy geometries. We find that at high frequencies, hurricane balls provide an easily realized and testable example of the Poinsot theory of freely rotating symmetrical bodies.

  8. Hurricane Season: Are You Ready?

    Centers for Disease Control (CDC) Podcasts

    2012-09-24

    Hurricanes are one of Mother Nature’s most powerful forces. Host Bret Atkins talks with CDC’s National Center for Environmental Health Director Dr. Chris Portier about the main threats of a hurricane and how you can prepare.  Created: 9/24/2012 by Office of Public Health Preparedness and Response (OPHPR), National Center for Environmental Health (NCEH), and the Agency for Toxic Substances and Disease Registry (ATSDR).   Date Released: 9/24/2012.

  9. A metastatistical approach to modelling extreme hurricane intensities

    Science.gov (United States)

    Hosseini, Seyed Reza; Marani, Marco; Scaioni, Marco

    2017-04-01

    Estimating the probability of occurrence of extreme hurricane intensities is significant in a vast number of fields and plays a crucial role in hurricane risk assessment. The method typically employed for these analyses applies traditional Extreme Value Theory (EVT) to fit the Generalize Extreme Value Distribution (GEVD) to hurricane maximum wind speed. In this framework, an asymptotic regime or a Poisson occurrence process are assumed to derive the GEVD, which is fitted using values over a high threshold or yearly maxima. However, the relative rarity of hurricanes implies that the number of events per year is not nearly sufficient for this asymptotic hypothesis to be valid, and the selection of a subset of the events drastically reduces the amount of information used. To overcome this limitation, we apply an alternative approach based on the Metastatistical Extreme Value Distribution (MEVD) to extreme hurricane intensity analyses. The derivation of the MEVD relaxes the limiting assumption of the traditional EVT, by taking into account the distribution of the entire range of recorded event magnitudes, rather than just the distributional tail. Taking advantage of this method, we can use the entire observational set, including hurricanes with relatively lower intensities, with clear statistical advantages. We comparatively assess the MEVD and the classical EVT quantile estimation uncertainties using the 130-year long Maximum Sustained Wind (MSW) speed time series for all hurricanes in the north Atlantic basin obtained from the National Hurricane Center (Atlantic HURDAT2). The parameters of the GEVD are estimated using a range of methods to ensure an optimal estimator is found. The MEVD is fitted assuming a Generalize Pareto Distribution (GPD) for the "ordinary" values of MSW over 5- to 10-year blocks using Probability Weighted Moments (PWM). The statistical tests are performed by dividing the dataset (of length L) into two distinct parts: S years for calibration and

  10. Impacts of cloud flare-ups on hurricane intensity resulting from departures from balance laws

    Directory of Open Access Journals (Sweden)

    T. N. Krishnamurti

    2012-05-01

    Full Text Available Cloud flare-ups along the inner eye wall of a hurricane lead to enhancement of cloud scale divergence, which in turn leads to a large local enhancement of the departure from balance laws and can lead to local supergradient winds. This scenario is tested using the results from a mesoscale microphysical model at horizontal resolution of 1.33 km for the simulation of hurricane Katrina. Rainwater mixing ratio tags growing cloud elements. The departure from balance laws includes terms such as the local, horizontal and vertical advections of divergence, divergence square and a term invoking the gradient of vertical velocity. It is noted that these terms collectively contribute to a substantial local enhancement of the departure from balance laws. Departures from balance laws are related to the radial gradient wind imbalances in a storm-centred coordinate. In this study, several examples, from the hurricane Katrina simulations, that display this scenario of rapid intensification are illustrated. Organisation of convection in the azimuthal direction seems important for the hurricane scale; cloud flare-ups away from such regions of azimuthal organisation fail to contribute to this scenario for the overall intensification of the hurricane.

  11. Dependence of Hurricane Intensity and Structures on Vertical Resolution and Time-Step Size

    Institute of Scientific and Technical Information of China (English)

    Da-Lin ZHANG; Xiaoxue WANG

    2003-01-01

    In view of the growing interests in the explicit modeling of clouds and precipitation, the effects of varyingvertical resolution and time-step sizes on the 72-h explicit simulation of Hurricane Andrew (1992) arestudied using the Pennsylvania State University/National Center for Atmospheric Research (PSU/NCAR)mesoscale model (i.e., MMS) with the finest grid size of 6 km. It is shown that changing vertical resolutionand time-step size has significant effects on hurricane intensity and inner-core cloud/precipitation, butlittle impact on the hurricane track. In general, increasing vertical resolution tends to produce a deeperstorm with lower central pressure and stronger three-dimensional winds, and more precipitation. Similareffects, but to a less extent, occur when the time-step size is reduced. It is found that increasing thelow-level vertical resolution is more efficient in intensifying a hurricane, whereas changing the upper-levelvertical resolution has little impact on the hurricane intensity. Moreover, the use of a thicker surface layertends to produce higher maximum surface winds. It is concluded that the use of higher vertical resolution,a thin surface layer, and smaller time-step sizes, along with higher horizontal resolution, is desirable tomodel more realistically the intensity and inner-core structures and evolution of tropical storms as well asthe other convectively driven weather systems.

  12. Data Fusion Between Microwave and Thermal Infrared Radiometer Data and Its Application to Skin Sea Surface Temperature, Wind Speed and Salinity Retrievals

    Directory of Open Access Journals (Sweden)

    Kohei Arai

    2013-03-01

    Full Text Available Method for data fusion between Microwave Scanning Radiometer: MSR and Thermal Infrared Radiometer: TIR derived skin sea surface temperature: SSST, wind speed: WS and salinity is proposed. SSST can be estimated with MSR and TIR radiometer data. Although the contribution ocean depth to MSR and TIR radiometer data are different each other, SSST estimation can be refined through comparisons between MSR and TIR derived SSST. Also WS and salinity can be estimated with MSR data under the condition of the refined SSST. Simulation study results support the idea of the proposed data fusion method.

  13. Estimation of Phytoplankton Responses to Hurricane Gonu over the Arabian Sea Based on Ocean Color Data

    Directory of Open Access Journals (Sweden)

    Hui Zhao

    2008-08-01

    Full Text Available In this study the authors investigated phytoplankton variations in the Arabian Sea associated with Hurricane Gonu using remote-sensing data of chlorophyll-a (Chl-a, sea surface temperature (SST and winds. Additional data sets used for the study included the hurricane and Conductivity-Temperature-Depth data. Hurricane Gonu, presenting extremely powerful wind intensity, originated over the central Arabian Sea (near 67.7ºE, 15.1ºN on June 2, 2007; it traveled along a northwestward direction and made landfall in Iran around June 7. Before Hurricane Gonu, Chl-a data indicated relatively low phytoplankton biomass (0.05-0.2 mg m-3, along with generally high SST (>28.5 ºC and weak wind (<10 m s-1 in the Arabian Sea. Shortly after Gonu’s passage, two phytoplankton blooms were observed northeast of Oman (Chl-a of 3.5 mg m-3 and in the eastern central Arabian Sea (Chl-a of 0.4 mg m-3, with up to 10-fold increase in surface Chl-a concentrations, respectively. The Chl-a in the two post-hurricane blooms were 46% and 42% larger than those in June of other years, respectively. The two blooms may be attributed to the storm-induced nutrient uptake, since hurricane can influence intensively both dynamical and biological processes through vertical mixing and Ekman Pumping.

  14. County-level hurricane exposure and birth rates: application of difference-in-differences analysis for confounding control.

    Science.gov (United States)

    Grabich, Shannon C; Robinson, Whitney R; Engel, Stephanie M; Konrad, Charles E; Richardson, David B; Horney, Jennifer A

    2015-01-01

    Epidemiological analyses of aggregated data are often used to evaluate theoretical health effects of natural disasters. Such analyses are susceptible to confounding by unmeasured differences between the exposed and unexposed populations. To demonstrate the difference-in-difference method our population included all recorded Florida live births that reached 20 weeks gestation and conceived after the first hurricane of 2004 or in 2003 (when no hurricanes made landfall). Hurricane exposure was categorized using ≥74 mile per hour hurricane wind speed as well as a 60 km spatial buffer based on weather data from the National Oceanic and Atmospheric Administration. The effect of exposure was quantified as live birth rate differences and 95 % confidence intervals [RD (95 % CI)]. To illustrate sensitivity of the results, the difference-in-differences estimates were compared to general linear models adjusted for census-level covariates. This analysis demonstrates difference-in-differences as a method to control for time-invariant confounders investigating hurricane exposure on live birth rates. Difference-in-differences analysis yielded consistently null associations across exposure metrics and hurricanes for the post hurricane rate difference between exposed and unexposed areas (e.g., Hurricane Ivan for 60 km spatial buffer [-0.02 births/1000 individuals (-0.51, 0.47)]. In contrast, general linear models suggested a positive association between hurricane exposure and birth rate [Hurricane Ivan for 60 km spatial buffer (2.80 births/1000 individuals (1.94, 3.67)] but not all models. Ecological studies of associations between environmental exposures and health are susceptible to confounding due to unmeasured population attributes. Here we demonstrate an accessible method of control for time-invariant confounders for future research.

  15. Using CloudSat and MODIS for exploring a hurricane intensity estimation technique

    Science.gov (United States)

    Alexander, R. J.

    2012-12-01

    Observing Tropical Cyclones (TC) using satellites is a common and successful endeavor. However, using satellites to accurately measure storm intensity is a more difficult and involved task. Our research aim to accurately measure hurricane intensity using only satellite obtained data. Modeling a hurricane as a balanced convectively neutral vortex, along with assumptions on the contributing factors to moist static energy, we explore techniques for estimating hurricane intensity. We used maximum sustained wind to characterize hurricane intensity. We calculated maximum sustained wind using the Wong and Emanuel expression for peak wind speed in a storm. CloudSat cloud profiling radar was used for obtaining cloud-top height and cloud composition information, and the MODIS instrument on-board Aqua was used to obtain cloud-top temperature. This technique requires eye or near eye overpass and simultaneous data collection and as a result have a limited sample size. We compare our results to the best track database and analyze the validity of our estimations.

  16. Landscape analysis and pattern of hurricane impact and circulation on mangrove forests of the everglades

    Science.gov (United States)

    Doyle, T.W.; Krauss, K.W.; Wells, C.J.

    2009-01-01

    The Everglades ecosystem contains the largest contiguous tract of mangrove forest outside the tropics that were also coincidentally intersected by a major Category 5 hurricane. Airborne videography was flown to capture the landscape pattern and process of forest damage in relation to storm trajectory and circulation. Two aerial video transects, representing different topographic positions, were used to quantify forest damage from video frame analysis in relation to prevailing wind force, treefall direction, and forest height. A hurricane simulation model was applied to reconstruct wind fields corresponding to the ground location of each video frame and to correlate observed treefall and destruction patterns with wind speed and direction. Mangrove forests within the storm's eyepath and in the right-side (forewind) quadrants suffered whole or partial blowdowns, while left-side (backwind) sites south of the eyewall zone incurred moderate canopy reduction and defoliation. Sites along the coastal transect sustained substantially more storm damage than sites along the inland transect which may be attributed to differences in stand exposure and/or stature. Observed treefall directions were shown to be non-random and associated with hurricane trajectory and simulated forewind azimuths. Wide-area sampling using airborne videography provided an efficient adjunct to limited ground observations and improved our spatial understanding of how hurricanes imprint landscape-scale patterns of disturbance. ?? 2009 The Society of Wetland Scientists.

  17. Hurricane Sandy washover deposits on Fire Island, New York

    Science.gov (United States)

    La Selle, SeanPaul M.; Lunghino, Brent D.; Jaffe, Bruce E.; Gelfenbaum, Guy; Costa, Pedro J.M.

    2017-02-16

    Washover deposits on Fire Island, New York, from Hurricane Sandy in 2012 were investigated a year after the storm to document the sedimentary characteristics of hurricane washover features. Sediment data collected in the field includes stratigraphic descriptions and photos from trenches, bulk sediment samples, U-channels, and gouge and push cores. Samples and push cores were further analyzed in the laboratory for grain size, density variations using x-ray computed tomography (CT), and surface microtexture using a scanning electron microscope (SEM). Elevation profiles of washover features were measured using Differential Global Positioning System (DGPS) with Real Time Kinematic processing. The DGPS elevations were compared to lidar (light detection and ranging) data from pre- and post-Sandy surveys to assess the degree to which washover deposit thicknesses changed within the year following deposition. Hurricane Sandy washover deposits as much as 1 meter thick were observed in trenches. Initial results show that the upper parts of the deposits have been reworked significantly in some places by wind, but there are still areas where the deposits are almost entirely intact. Where mostly intact, the washover deposits consist of massive or weakly laminated sand near the base, overlain by more strongly laminated sands.

  18. Meeting the Science Needs of the Nation in the Wake of Hurricane Sandy-- A U.S. Geological Survey Science Plan for Support of Restoration and Recovery

    Science.gov (United States)

    Buxton, Herbert T.; Andersen, Matthew E.; Focazio, Michael J.; Haines, John W.; Hainly, Robert A.; Hippe, Daniel J.; Sugarbaker, Larry J.

    2013-01-01

    n late October 2012, Hurricane Sandy came ashore during a spring high tide on the New Jersey coastline, delivering hurricane-force winds, storm tides exceeding 19 feet, driving rain, and plummeting temperatures. Hurricane Sandy resulted in 72 direct fatalities in the mid-Atlantic and northeastern United States, and widespread and substantial physical, environmental, ecological, social, and economic impacts estimated at near $50 billion. Before the landfall of Hurricane Sandy, the USGS provided forecasts of potential coastal change; collected oblique aerial photography of pre-storm coastal morphology; deployed storm-surge sensors, rapid-deployment streamgages, wave sensors, and barometric pressure sensors; conducted Light Detection And Ranging (lidar) aerial topographic surveys of coastal areas; and issued a landslide alert for landslide prone areas. During the storm, Tidal Telemetry Networks provided real-time water-level information along the coast. Long-term network and rapid-deployment real-time streamgages and water-quality monitors reported on river levels and changes in water quality. Immediately after the storm, the USGS serviced real-time instrumentation, retrieved data from over 140 storm-surge sensors, and collected other essential environmental data, including more than 830 high-water marks mapping the extent and elevation of the storm surge. Post-storm lidar surveys documented storm impacts to coastal barriers informing response and recovery and providing a new baseline to assess vulnerability of the reconfigured coast. The USGS Hazard Data Distribution System served storm related information from many agencies on the Internet on a daily basis. This science plan was developed immediately following Hurricane Sandy to coordinate continuing USGS activities with other agencies and to guide continued data collection and analysis to ensure support for recovery and restoration efforts. The data, information, and tools that are produced by implementing this

  19. Improving the wind and wave estimation of dual-frequency altimeter JASON1 in Typhoon Shanshan and considering the rain effects

    Institute of Scientific and Technical Information of China (English)

    YANG Le; LIN Mingsen; ZOU Juhong; LI Zhenghua; PAN Delu

    2008-01-01

    Altimetry data have been widely used in various fields of oceanography, including the extreme weather events such as tropical cyclones, typhoons, and hurricanes. The performance of JASONI in Typhoon Shanshan is assessed by examining the sensor geophysical data record and illustrates how the measured return waveform, significant wave height, and backscatter are all affected by various factors associated with the typhoon, with details by the rain are illustrated. The correction method to maintain accurate wave height and wind speed measurements in Typhoon Shanshan and the results are presented. Furthermore, the additional results of rain rate and typhoon eye diameter can be retrieved. Because of the lack of in-situ measurements of wind, wave, and rain rate at Typhoon Shanshan, results are compared with the forecasted typhoon data and a good agreement is found.

  20. Hurricane damage assessment for residential construction considering the non-stationarity in hurricane intensity and frequency

    Institute of Scientific and Technical Information of China (English)

    WANG Cao; LI Quanwang; PANG Long; ZOU Aming; ZHANG Long

    2016-01-01

    Natural hazards such as hurricanes may cause extensive economic losses and social disruption for civil structures and infrastructures in coastal areas, implying the importance of understanding the construction performance subjected to hurricanes and assessing the hurricane damages properly. The intensity and frequency of hurricanes have been reported to change with time due to the potential impact of climate change. In this paper, a probability-based model of hurricane damage assessment for coastal constructions is proposed taking into account the non-stationarity in hurricane intensity and frequency. The non-homogeneous Poisson process is employed to model the non-stationarity in hurricane occurrence while the non-stationarity in hurricane intensity is reflected by the time-variant statistical parameters (e.g., mean value and/or standard deviation), with which the mean value and variation of the cumulative hurricane damage are evaluated explicitly. The Miami-Dade County, Florida, USA, is chosen to illustrate the hurricane damage assessment method proposed in this paper. The role of non-stationarity in hurricane intensity and occurrence rate due to climate change in hurricane damage is investigated using some representative changing patterns of hurricane parameters.

  1. Hurricanes Karl and Tropical Storm Matthew Structure Observed by HIWRAP During GRIP

    Science.gov (United States)

    Heymsfield, G. M.; Guimond, S. R.; Tian, L.

    2012-12-01

    The dual-wavelength (Ku and Ka band) High-Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP) flew for the first time on the Global Hawk during the 2010 Genesis and Rapid Intensification Processes (GRIP). HIWRAP is conical scanning and Doppler, and winds and reflectivity can be mapped within the swath below the Global Hawk. Two interesting cases from the HIWRAP flights were the rapid intensification of Hurricane Karl and the intensification of Tropical Storm Matthew. This presentation will highlight the precipitation and wind structure of these storms during their intensification as derived from the HIWRAP observations. If time permits and if available, highlights from HIWRAP observations from the Hurricane Severe Storm Sentinel (HS3) field campaign in September 2012 will be presented.

  2. 77 FR 64564 - Implementation of Regulatory Guide 1.221 on Design-Basis Hurricane and Hurricane Missiles

    Science.gov (United States)

    2012-10-22

    ... COMMISSION Implementation of Regulatory Guide 1.221 on Design-Basis Hurricane and Hurricane Missiles AGENCY....221 on Design-Basis Hurricane and Hurricane Missiles.'' The purpose of this ISG is to supplement the guidance regarding the application of Regulatory Guide 1.221, ``Design-Basis Hurricane and...

  3. Extrapolating Satellite Winds to Turbine Operating Heights

    DEFF Research Database (Denmark)

    Badger, Merete; Pena Diaz, Alfredo; Hahmann, Andrea N.;

    2016-01-01

    Ocean wind retrievals from satellite sensors are typically performed for the standard level of 10 m. This restricts their full exploitation for wind energy planning, which requires wind information at much higher levels where wind turbines operate. A new method is presented for the vertical extra...

  4. Rapid Response Measurements of Hurricane Waves and Storm Surge

    Science.gov (United States)

    Gravois, U.

    2010-12-01

    Andrew (1992), Katrina (2005), and Ike (2008) are recent examples of extensive damage that resulted from direct hurricane landfall. Some of the worst damages from these hurricanes are caused by wind driven waves and storm surge flooding. The potential for more hurricane disasters like these continues to increase as a result of population growth and real estate development in low elevation coastal regions. Observational measurements of hurricane waves and storm surge play an important role in future mitigation efforts, yet permanent wave buoy moorings and tide stations are more sparse than desired. This research has developed a rapid response method using helicopters to install temporary wave and surge gauges ahead of hurricane landfall. These temporary installations, with target depths from 10-15 m and 1-7 km offshore depending on the local shelf slope, increase the density of measurement points where the worst conditions are expected. The method has progressed to an operational state and has successfully responded to storms Ernesto (2006), Noel (2007), Fay (2008), Gustav (2008), Hanna (2008) and Ike (2008). The temporary gauges are pressure data loggers that measure at 1 Hz continuously for 12 days and are post-processed to extract surge and wave information. For the six storms studied, 45 out of 49 sensors were recovered by boat led scuba diver search teams, with 43 providing useful data for an 88 percent success rate. As part of the 20 sensor Hurricane Gustav response, sensors were also deployed in lakes and bays inLouisiana, east of the Mississippi river delta. Gustav was the largest deployment to date. Generally efforts were scaled back for storms that were not anticipated to be highly destructive. For example, the cumulative total of sensors deployed for Ernesto, Noel, Fay and Hanna was only 20. Measurement locations for Gustav spanned over 800 km of exposed coastline from Louisiana to Florida with sensors in close proximity to landfall near Cocodrie

  5. Forecasting hurricane impact on coastal topography: Hurricane Ike

    Science.gov (United States)

    Plant, Nathaniel G.; Stockdon, Hilary F.; Sallenger,, Asbury H.; Turco, Michael J.; East, Jeffery W.; Taylor, Arthur A.; Shaffer, Wilson A.

    2010-01-01

    Extreme storms can have a profound impact on coastal topography and thus on ecosystems and human-built structures within coastal regions. For instance, landfalls of several recent major hurricanes have caused significant changes to the U.S. coastline, particularly along the Gulf of Mexico. Some of these hurricanes (e.g., Ivan in 2004, Katrina and Rita in 2005, and Gustav and Ike in 2008) led to shoreline position changes of about 100 meters. Sand dunes, which protect the coast from waves and surge, eroded, losing several meters of elevation in the course of a single storm. Observations during these events raise the question of how storm-related changes affect the future vulnerability of a coast.

  6. Physical attributes of hurricane surges and their role in surge warning

    Science.gov (United States)

    Irish, J. L.

    2012-12-01

    In the last decade, the US has experienced some of its largest surges and hurricane-related damages on record. Effective evacuation in advance of a hurricane strike requires accurate estimation of the hurricane surge hazard that effectively conveys risk not only to government decision makers but also to the general public. Two primary challenges exist with the current structure for surge warning. First, existing computational methods for developing accurate, quantitative surge forecasts, namely surge height and inundation estimation, are limited by time and computational resources. Second, due primarily to the popularity and wide use of the Saffir-Simpson wind scale to convey the complete hurricane hazard, the public's perception of surge hazard is inaccurate. Here, we use dimensionless scaling and hydrodynamics arguments to quantify the influence of hurricane variables and regional geographic characteristics on the surge response. It will be shown that hurricane surge primarily scales with the hurricane's central pressure, and size and with continental shelf width at the landfall location (Irish et al. 2009, Nat. Haz.; Song et al. in press, Nat. Haz.). Secondary influences include the hurricane's forward speed and path. The developed physical scaling is applied in two ways: (1) as a means for expanding the utility of computational simulations for real-time surge height forecasting and (2) as a means to convey relative surge hazard via a readily evaluated algebraic surge scale. In the first application, the use of this physical scaling to develop surge response functions (SRF) enables instantaneous algebraic calculation of maximum surge height at any location of interest for any hurricane meteorological condition, without loss of accuracy gained via high-resolution computational simulation. When coupled with joint probability statistics, the use of SRFs enables rapid development of continuous probability density functions for probabilistic surge forecasting (Irish

  7. Hurricane Footprints in Global Climate Models

    Directory of Open Access Journals (Sweden)

    Francisco J. Tapiador

    2008-11-01

    Full Text Available This paper addresses the identification of hurricanes in low-resolution global climate models (GCM. As hurricanes are not fully resolvable at the coarse resolution of the GCMs (typically 2.5 × 2.5 deg, indirect methods such as analyzing the environmental conditions favoring hurricane formation have to be sought. Nonetheless, the dynamical cores of the models have limitations in simulating hurricane formation, which is a far from fully understood process. Here, it is shown that variations in the specific entropy rather than in dynamical variables can be used as a proxy of the hurricane intensity as estimated by the Accumulated Cyclone Energy (ACE. The main application of this research is to ascertain the changes in the hurricane frequency and intensity in future climates.

  8. Differences in impacts of Hurricane Sandy on freshwater swamps on the Delmarva Peninsula, Mid−Atlantic Coast, USA

    Science.gov (United States)

    Middleton, Beth A.

    2016-01-01

    Hurricane wind and surge may have different influences on the subsequent composition of forests. During Hurricane Sandy, while damaging winds were highest near landfall in New Jersey, inundation occurred along the entire eastern seaboard from Georgia to Maine. In this study, a comparison of damage from salinity intrusion vs. wind/surge was recorded in swamps of the Delmarva Peninsula along the Pocomoke (MD) and Nanticoke (DE) Rivers, south of the most intense wind damage. Hickory Point Cypress Swamp (Hickory) was closest to the Chesapeake Bay and may have been subjected to a salinity surge as evidenced by elevated salinity levels at a gage upstream of this swamp (storm salinity = 13.1 ppt at Nassawango Creek, Snow Hill, Maryland). After Hurricane Sandy, 8% of the standing trees died at Hickory including Acer rubrum, Amelanchier laevis, Ilex spp., and Taxodium distichum. In Plot 2 of Hickory, 25% of the standing trees were dead, and soil salinity levels were the highest recorded in the study. The most important variables related to structural tree damage were soil salinity and proximity to the Atlantic coast as based on Stepwise Regression and NMDS procedures. Wind damage was mostly restricted to broken branches although tipped−up trees were found at Hickory, Whiton and Porter (species: Liquidamabar styraciflua, Pinus taeda, Populus deltoides, Quercus pagoda and Ilex spp.). These trees fell mostly in an east or east−southeast direction (88o−107o) in keeping with the wind direction of Hurricane Sandy on the Delmarva Peninsula. Coastal restoration and management can be informed by the specific differences in hurricane damage to vegetation by salt versus wind.

  9. Hurricane Effects on Mangrove Canopies Observed from MODIS and SPOT Imagery

    CERN Document Server

    Parenti, Michael

    2014-01-01

    The effects of four hurricanes on protected mangroves in southwest Florida (Katrina and Wilma) and the Yucatan Peninsula (Emily and Dean) were assessed using paired sets of 20m multispectral SPOT and 16-day 500m MODIS images. The normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI) were used to assess possible damage to and recovery of mangrove canopies associated with each storm event. The results revealed decreases in the NDVI and EVI of mangrove canopies consistent with storm effects, although the effects in South Florida and Sian Ka'an were highly variable. Hurricane Wilma produced a large decrease in NDVI and EVI although values recovered within a year, suggesting resilience to this storm. Rainfall associated with Hurricane Emily apparently increased mangrove photosynthetic activity owing to the location of landfall outside the study area, the small size of the wind field and the apparent lack of storm surge. MODIS NDVI time series revealed pronounced seasonality in mangrove ...

  10. Relationships between the North Pacific Oscillation and the typhoon/hurricane frequencies

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Relationships between the North Pacific Oscillation (NPO) and the typhoon as well as hurricane frequencies are documented. The correlation between NPO index in June-July-August-September and the annual typhoon number in the western North Pacific is 0.37 for the period of 1949―1998. The NPO is correlated with the annual hurricane number in the tropical Atlantic at - 0.28 for the same period. The variability of NPO is found to be concurrent with the changes of the magnitude of vertical zonal wind shear, sea-level pressure patterns, as well as the sea surface temperature, which are physically associated with the typhoons and hurricanes genesis. The NPO associated atmospheric circulation variability is analyzed to explain how NPO is linked with variability of the tropical atmospheric circulation in the western Pacific and the tropical Atlantic, via the atmospheric teleconnection.

  11. The impact of T-TREC-retrieved wind and radial velocity data assimilation using EnKF and effects of assimilation window on the analysis and prediction of Typhoon Jangmi (2008)

    Science.gov (United States)

    Wang, Mingjun; Xue, Ming; Zhao, Kun

    2016-01-01

    This study examines the relative impact of assimilating T-TREC-retrieved winds (VTREC) versus radial velocity (Vr) on the analysis and forecast of Typhoon Jangmi (2008) using an ensemble Kalman filter (EnKF). The VTREC and Vr data at 30 min intervals are assimilated into the ARPS model at 3 km grid spacing over four different assimilation windows that cover, respectively, 0000-0200, 0200-0400, 0400-0600, and 0000-0600 UTC, 28 September 2008. The assimilation of VTREC data produces better analyses of the typhoon structure and intensity than the assimilation of Vr data during the earlier assimilation windows, but during the later assimilation windows when the coverage of Vr data on the typhoon from four Doppler radars is much improved, the assimilation of Vr outperforms VTREC data. The combination of VTREC and Vr data, either by assimilating both VTREC and Vr data in all cycles or by assimilating VTREC in the first cycle and Vr in the remaining cycles (labeled VTFVR), further improves the analyses of the typhoon structure and intensity compared to assimilating VTREC or Vr data alone. Quantitative verifications of 24 h forecasts of the typhoon show that the VTFVR assimilation experiments produces forecasts that best match the best track data and also have the highest precipitation prediction skills. The track forecast errors in experiment that assimilate VTREC data through the later cycles are the largest. The behaviors are discussed based on the coverage, information content, and accuracy of the various forms of data.

  12. The science and politics of forest management in Northern Nicaragua after hurricane Felix (2007)

    Science.gov (United States)

    Rossi Idarraga, Esteban

    This dissertation examines the ecological effects of hurricane Felix (2007) in Northern Nicaragua as well as the socio-political factors that influenced forest management efforts in hurricane impacted locations. Specifically, this research focused on the following questions: first, what were the regional damage patterns caused by hurricane Felix on the forests of Northern Nicaragua? Second, what stand and tree attributes explain observed post-hurricane damage patterns? And, third, why were post-hurricane management efforts unsuccessful? The first dissertation article characterizes the intensity and spatial distribution of forest damage after hurricane Felix using satellite imagery from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor and aerial photographs. Results indicated that Broadleaf forests experienced larger damage (>75% trees blown down) than Pine forest, and that Enhanced Vegetation Index data (EVI), obtained from the MODIS sensor, can adequately depict post-hurricane damage in tropical forests. The agreement between the obtained EVI damage map and the reference data set ranged from 91% in high-damage locations to 85% in low-damage locations, with 86% overall agreement. The second dissertation article describes the relationship between hurricane damage patterns and ecological variables at the local level. Specifically, it characterizes the relationship between tree-and-stand attributes (i.e. DBH, height, density, basal area) and wind damage, using field data. Findings indicate that tree attributes such as DBH and height strongly influenced the amount and type of wind damage and that stand attributes such as maximum canopy height and distance to the hurricane path were also predictive of the amount of damage. Observed differences in damage patterns among broadleaf and pine forests were strongly correlated with the height to diameter ratio (H/D). Field observations showed that while post-hurricane regeneration was abundant in broadleaf

  13. The great Louisiana hurricane of August 1812

    OpenAIRE

    Mock, Cary J.; Chenoweth, Michael; Altamirano, Isabel; Rodgers, Matthew D.; García Herrera, Ricardo

    2010-01-01

    Major hurricanes are prominent meteorological hazards of the U.S. Atlantic and Gulf coasts. However, the official modern record of Atlantic basin tropical cyclones starts at 1851, and it does not provide a comprehensive measure of the frequency and magnitude of major hurricanes. Vast amounts of documentary weather data extend back several centuries, but many of these have not yet been fully utilized for hurricane reconstruction. These sources include weather diaries, ship logbooks, ship prote...

  14. An overview on SAR measurements of sea surface wind

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Studies show that synthetic aperture radar (SAR) has the capability of providing high-resolution (sub-kilometer) sea surface wind fields. This is very useful for applications where knowledge of the sea surface wind at fine scales is crucial. This paper aims to review the latest work on sea surface wind field retrieval using SAR images. As shown, many different approaches have been developed for retrieving wind speed and wind direction. However, much more work will be required to fully exploit the SAR data for improving the retrieval accuracy of high-resolution winds and for producing wind products in an operational sense.

  15. Raindrop Size Distribution Retrieval from Wind Profiler Radar Based on Double-Gaussian Fitting%基于双高斯拟合的风廓线雷达反演雨滴谱

    Institute of Scientific and Technical Information of China (English)

    何越; 何平; 林晓萌

    2014-01-01

    The raindrop size distribution is extremely important for understanding the physical process of cloud and fog formation,and the generation of natural rainfall.It is a major tool that can be used to assess the cloud conditions for weather modification and verify associated results,in addition to being an important scientific evidence for numerical modeling.The weather radar often uses the method of PPP (Pulse Pair Processing)to process the signal,so it cannot get the raindrop size data directly.However,wind profiler radar is invented to detect the turbulence of clear air and it can obtain the distribution of Doppler velocity of precipitation particles,hence data can be used to retrieve raindrop spectral of precipitation effectively.Un-der the condition of precipitation,the return information of wind profiler radar is superimposed by turbu-lent signal and precipitation signal,and the power spectrum would often appear an obvious bimodal struc-ture.Some representative precipitation data of Yanqing,Beijing in 2006 and 2012 are analyzed,by the method of removing noise and calibration curve,the power spectrum of antenna array is retrieved and then a more accurate signal power spectrum is obtained.The method of double-Gaussian fitting is used to dis-tinguish the power spectrum of atmospheric turbulence signal and the power spectrum of precipitation sig-nal.The signal is used to estimate a better raindrop size distribution after removing effects of air turbu-lence.According to relations between precipitation particles and diameters,the raindrop spectrum can be obtained easily.Through analyses and comparisons of different intensity and types of retrieved raindrop size distribution data,it can be concluded that in the process of estimating the raindrop size distribution from wind profiler radar,the method of double-Gaussian fitting could separate two peaks effectively,and the precision is more accurate and the structure emerges an exponential form basically.The result shows

  16. Hurricane Excitation of Earth Eigenmodes

    OpenAIRE

    Peters, Randall D.

    2005-01-01

    A non-conventional vertical seismometer, with good low-frequency sensitivity, was used to study earth motions in Macon, Georgia USA during the time of hurricane Charley, August 2004. During its transitions between water and land, the powerful storm showed an interesting history of microseisms and also generated more than half-a-dozen surprisingly coherent oscillations, whose frequencies ranged from 0.9 to 3 mHz.

  17. Hurricane Boundary-Layer Theory

    Science.gov (United States)

    2010-01-01

    2501. Kundu PK. 1990. Fluid Mechanics . Academic Press: San Diego, USA. Kuo HL. 1982. Vortex boundary layer under quadratic surface stress. Boundary...identification of two mechanisms for the spin-up of the mean tangential circulation of a hurricane. The first involves convergence of absolute angular...momentum above the boundary layer, where this quantity is approximately conserved. This mechanism acts to spin up the outer circulation at radii

  18. Lessons Learnt From Hurricane Katrina.

    Science.gov (United States)

    Akundi, Murty

    2008-03-01

    Hurricane Katrina devastated New Orleans and its suburbs on Monday August 29^th, 2005. The previous Friday morning, August 26, the National Hurricane Center indicated that Katrina was a Category One Hurricane, which was expected to hit Florida. By Friday afternoon, it had changed its course, and neither the city nor Xavier University was prepared for this unexpected turn in the hurricane's path. The university had 6 to 7 ft of water in every building and Xavier was closed for four months. Students and university personnel that were unable to evacuate were trapped on campus and transportation out of the city became a logistical nightmare. Email and all electronic systems were unavailable for at least a month, and all cell phones with a 504 area code stopped working. For the Department, the most immediate problem was locating faculty and students. Xavier created a list of faculty and their new email addresses and began coordinating with faculty. Xavier created a web page with advice for students, and the chair of the department created a separate blog with contact information for students. The early lack of a clear method of communication made worse the confusion and dismay among the faculty on such issues as when the university would reopen, whether the faculty would be retained, whether they should seek temporary (or permanent) employment elsewhere, etc. With the vision and determination of President Dr. Francis, Xavier was able to reopen the university in January and ran a full academic year from January through August. Since Katrina, the university has asked every department and unit to prepare emergency preparedness plans. Each department has been asked to collect e-mail addresses (non-Xavier), cell phone numbers and out of town contact information. The University also established an emergency website to communicate. All faculty have been asked to prepare to teach classes electronically via Black board or the web. Questions remain about the longer term issues of

  19. Efficient coordination of swarms of sensor-laden balloons for persistent, in situ, real-time measurement of hurricane development*

    Science.gov (United States)

    Bewley, Thomas; Meneghello, Gianluca

    2016-10-01

    Accurate long-term forecasts of the path and intensity of severe hurricanes are imperative to protect property and save lives. Extensive real-time measurements within hurricanes, especially near their core, are essential for supplementing the limited relevant information accessible by satellites in order to improve such forecasts. Current operational methods for obtaining in situ information, such as dropsondes and repeated manned and unmanned aircraft flights over and within hurricanes, are both expensive and limited in duration. In the present work it is demonstrated by numerical experiments how a swarm of robust, inexpensive, buoyancy-controlled, sensor-laden balloons might be deployed and controlled in an energetically efficient, coordinated fashion, for days at a time, to continuously monitor relevant properties (pressure, humidity, temperature, and wind speed) of a hurricane as it develops. Rather than fighting its gale-force winds, the strong and predictable stratification of these winds is leveraged to efficiently disperse the balloons into a favorable time-evolving distribution. An iterative bootstrap approach is envisioned in which (a) sensor balloons are used to help improve the available computational estimate of the uncertain and underresolved flow field of the hurricane and (b) this (imprecise) estimate of the hurricane flow field is leveraged to improve the distribution of the sensor balloons, which then better facilitates (a), etc. The control approach envisioned in this ambitious effort is a combination of (centrally computed) model predictive control for coordination at the largest scales, which is the focus of the present paper, coupled with a feedback control strategy (decentrally computed, on the balloons themselves), for smaller-scale corrections. Our work indicates that, following such an approach, certain target orbits of interest within the hurricane can be continuously sampled by some balloons, while others make repeated sweeps between the

  20. Dynamic Hurricane Data Analysis Tool

    Science.gov (United States)

    Knosp, Brian W.; Li, Peggy; Vu, Quoc A.

    2009-01-01

    A dynamic hurricane data analysis tool allows users of the JPL Tropical Cyclone Information System (TCIS) to analyze data over a Web medium. The TCIS software is described in the previous article, Tropical Cyclone Information System (TCIS) (NPO-45748). This tool interfaces with the TCIS database to pull in data from several different atmospheric and oceanic data sets, both observed by instruments. Users can use this information to generate histograms, maps, and profile plots for specific storms. The tool also displays statistical values for the user-selected parameter for the mean, standard deviation, median, minimum, and maximum values. There is little wait time, allowing for fast data plots over date and spatial ranges. Users may also zoom-in for a closer look at a particular spatial range. This is version 1 of the software. Researchers will use the data and tools on the TCIS to understand hurricane processes, improve hurricane forecast models and identify what types of measurements the next generation of instruments will need to collect.

  1. Modelling the response of Placentia Bay to hurricanes Igor and Leslie

    Science.gov (United States)

    Ma, Zhimin; Han, Guoqi; de Young, Brad

    2017-04-01

    A three-dimensional, baroclinic, finite-volume ocean model (FVCOM) is used to examine hurricane induced responses in Placentia Bay, Newfoundland. Hurricane Igor (2010) and Hurricane Leslie (2012) made landfall within 100 km of the mouth of the bay, with the former to the eastern side and the latter on the western side. The model results have reasonable agreement with field observations on sea level, near-surface currents and sea surface temperature (SST). During landfall the two hurricanes cause the opposite shifts in inner bay circulation. Hurricane Igor overwhelms the mean inflow into the inner bay and shifts the currents to outflow. Hurricane Leslie reinforces the inflow into the inner bay. The peak storm surge is significantly influenced by local wind and air pressure during Leslie, accounting for 34% and 62% at the Argentia and St. Lawrence tide-gauge stations respectively, but predominately due to remote forcing entering the upstream eastern open boundary during Igor. There is a strong near-surface near-inertial response during Leslie, but a weak one during Igor. Stratification plays an important role in both generation and dissipation of near-inertial oscillation. A strong pre-storm stratification during Leslie favours the generation of near-inertia oscillation. Strong turbulent mixing induced on the right side of Leslie generates large vertical movement of the thermocline and thus contributes to strong near-inertia oscillation inside the mixed layer. The barotropic simulation results in a significant underestimation of near-surface currents and near-inertial oscillation. The baroclinic simulation shows a large increase of the current gradient in the vertical, as the first baroclinic mode in response to the hurricane forcing.

  2. Environmental Modeling, Technology, and Communication for Land Falling Tropical Cyclone/Hurricane Prediction

    Directory of Open Access Journals (Sweden)

    Paul Tchounwou

    2010-04-01

    Full Text Available Katrina (a tropical cyclone/hurricane began to strengthen reaching a Category 5 storm on 28th August, 2005 and its winds reached peak intensity of 175 mph and pressure levels as low as 902 mb. Katrina eventually weakened to a category 3 storm and made a landfall in Plaquemines Parish, Louisiana, Gulf of Mexico, south of Buras on 29th August 2005. We investigate the time series intensity change of the hurricane Katrina using environmental modeling and technology tools to develop an early and advanced warning and prediction system. Environmental Mesoscale Model (Weather Research Forecast, WRF simulations are used for prediction of intensity change and track of the hurricane Katrina. The model is run on a doubly nested domain centered over the central Gulf of Mexico, with grid spacing of 90 km and 30 km for 6 h periods, from August 28th to August 30th. The model results are in good agreement with the observations suggesting that the model is capable of simulating the surface features, intensity change and track and precipitation associated with hurricane Katrina. We computed the maximum vertical velocities (Wmax using Convective Available Kinetic Energy (CAPE obtained at the equilibrium level (EL, from atmospheric soundings over the Gulf Coast stations during the hurricane land falling for the period August 21–30, 2005. The large vertical atmospheric motions associated with the land falling hurricane Katrina produced severe weather including thunderstorms and tornadoes 2–3 days before landfall. The environmental modeling simulations in combination with sounding data show that the tools may be used as an advanced prediction and communication system (APCS for land falling tropical cyclones/hurricanes.

  3. Hurricanes vs. Humans: Their Comparative Long-Term Effects on Tropical Landscapes.

    Science.gov (United States)

    Lugo, A. E.

    2002-12-01

    Puerto Rico experiences about 50 hurricanes per century. These large-scale events last for hours, but have significant short, medium, and long-term effects on vegetation and landscape processes as shown in studies in the Long-Term Ecological Research program. Forest canopy characteristics, tree mortality rates, life history characteristics of both plants and animals, successional rates, landslide occurrence, and sediment erosion and transport are examples of ecological and landscape attributes that exhibit strong responses to hurricane frequency and intensity. However, Puerto Rico has also undergone dramatic land cover change due to human activity. The island as a whole has experienced a cycle of deforestation, agricultural use, land abandonment, forest recovery, and urbanization. These anthropogenic events leave a long-term legacy on both individual ecosystems and the landscape as a whole. Species composition, structure, and age of forests are significantly influenced by human activity, as are rates of sediment erosion and transport, and frequency and size of landslides. I will present comparative data on the effects of hurricanes and human activity on Puerto Rico's forests and landscape. I address the following questions: which of these two forces that jointly shape the island's biota and landscape has a greater influence on functioning at the ecosystem level and what are the management implications? It appears that human impact on sediment erosion and transport events is greater than that of hurricanes and that humans change species composition of forests more than do hurricanes. However, regardless of the nature of the new ecosystems formed due to human activity, these systems must cope with the forces (rain and winds) of hurricanes in order to persist on the landscape. Regardless of the power of hurricanes, they don't appear to reset the human legacy on the island's landscape.

  4. Environmental modeling, technology, and communication for land falling tropical cyclone/hurricane prediction.

    Science.gov (United States)

    Tuluri, Francis; Reddy, R Suseela; Anjaneyulu, Y; Colonias, John; Tchounwou, Paul

    2010-05-01

    Katrina (a tropical cyclone/hurricane) began to strengthen reaching a Category 5 storm on 28th August, 2005 and its winds reached peak intensity of 175 mph and pressure levels as low as 902 mb. Katrina eventually weakened to a category 3 storm and made a landfall in Plaquemines Parish, Louisiana, Gulf of Mexico, south of Buras on 29th August 2005. We investigate the time series intensity change of the hurricane Katrina using environmental modeling and technology tools to develop an early and advanced warning and prediction system. Environmental Mesoscale Model (Weather Research Forecast, WRF) simulations are used for prediction of intensity change and track of the hurricane Katrina. The model is run on a doubly nested domain centered over the central Gulf of Mexico, with grid spacing of 90 km and 30 km for 6 h periods, from August 28th to August 30th. The model results are in good agreement with the observations suggesting that the model is capable of simulating the surface features, intensity change and track and precipitation associated with hurricane Katrina. We computed the maximum vertical velocities (W(max)) using Convective Available Kinetic Energy (CAPE) obtained at the equilibrium level (EL), from atmospheric soundings over the Gulf Coast stations during the hurricane land falling for the period August 21-30, 2005. The large vertical atmospheric motions associated with the land falling hurricane Katrina produced severe weather including thunderstorms and tornadoes 2-3 days before landfall. The environmental modeling simulations in combination with sounding data show that the tools may be used as an advanced prediction and communication system (APCS) for land falling tropical cyclones/hurricanes.

  5. Cumulative impacts of hurricanes on Florida mangrove ecosystems: Sediment deposition, storm surges and vegetation

    Science.gov (United States)

    Smith, T. J.; Anderson, G.H.; Balentine, K.; Tiling, G.; Ward, G.A.; Whelan, K.R.T.

    2009-01-01

    Hurricanes have shaped the structure of mangrove forests in the Everglades via wind damage, storm surges and sediment deposition. Immediate effects include changes to stem size-frequency distributions and to species relative abundance and density. Long-term impacts to mangroves are poorly understood at present. We examine impacts of Hurricane Wilma on mangroves and compare the results to findings from three previous storms (Labor Day, Donna, Andrew). Surges during Wilma destroyed ??? 1,250 ha of mangroves and set back recovery that started following Andrew. Data from permanent plots affected by Andrew and Wilma showed no differences among species or between hurricanes for stem mortality or basal area lost. Hurricane damage was related to hydro-geomorphic type of forest. Basin mangroves suffered significantly more damage than riverine or island mangroves. The hurricane by forest type interaction was highly significant. Andrew did slightly more damage to island mangroves. Wilma did significantly more damage to basin forests. This is most likely a result of the larger and more spatially extensive storm surge produced by Wilma. Forest damage was not related to amount of sediment deposited. Analyses of reports from Donna and the Labor Day storm indicate that some sites have recovered following catastrophic disturbance. Other sites have been permanently converted into a different ecosystem, namely intertidal mudflats. Our results indicate that mangroves are not in a steady state as has been recently claimed. ?? 2009 The Society of Wetland Scientists.

  6. Hurricane Activity and the Large-Scale Pattern of Spread of an Invasive Plant Species

    Science.gov (United States)

    Bhattarai, Ganesh P.; Cronin, James T.

    2014-01-01

    Disturbances are a primary facilitator of the growth and spread of invasive species. However, the effects of large-scale disturbances, such as hurricanes and tropical storms, on the broad geographic patterns of invasive species growth and spread have not been investigated. We used historical aerial imagery to determine the growth rate of invasive Phragmites australis patches in wetlands along the Atlantic and Gulf Coasts of the United States. These were relatively undisturbed wetlands where P. australis had room for unrestricted growth. Over the past several decades, invasive P. australis stands expanded in size by 6–35% per year. Based on tropical storm and hurricane activity over that same time period, we found that the frequency of hurricane-force winds explained 81% of the variation in P. australis growth over this broad geographic range. The expansion of P. australis stands was strongly and positively correlated with hurricane frequency. In light of the many climatic models that predict an increase in the frequency and intensity of hurricanes over the next century, these results suggest a strong link between climate change and species invasion and a challenging future ahead for the management of invasive species. PMID:24878928

  7. Hurricane activity and the large-scale pattern of spread of an invasive plant species.

    Science.gov (United States)

    Bhattarai, Ganesh P; Cronin, James T

    2014-01-01

    Disturbances are a primary facilitator of the growth and spread of invasive species. However, the effects of large-scale disturbances, such as hurricanes and tropical storms, on the broad geographic patterns of invasive species growth and spread have not been investigated. We used historical aerial imagery to determine the growth rate of invasive Phragmites australis patches in wetlands along the Atlantic and Gulf Coasts of the United States. These were relatively undisturbed wetlands where P. australis had room for unrestricted growth. Over the past several decades, invasive P. australis stands expanded in size by 6-35% per year. Based on tropical storm and hurricane activity over that same time period, we found that the frequency of hurricane-force winds explained 81% of the variation in P. australis growth over this broad geographic range. The expansion of P. australis stands was strongly and positively correlated with hurricane frequency. In light of the many climatic models that predict an increase in the frequency and intensity of hurricanes over the next century, these results suggest a strong link between climate change and species invasion and a challenging future ahead for the management of invasive species.

  8. National assessment of hurricane-induced coastal erosion hazards--Gulf of Mexico

    Science.gov (United States)

    Stockdon, Hilary F.; Doran, Kara S.; Thompson, David M.; Sopkin, Kristin L.; Plant, Nathaniel G.; Sallenger, Asbury H.

    2012-01-01

    Sandy beaches provide a natural barrier between the ocean and inland communities, ecosystems, and resources. However, these dynamic environments move and change in response to winds, waves, and currents. During a hurricane, these changes can be large and sometimes catastrophic. High waves and storm surge act together to erode beaches and inundate low-lying lands, putting inland communities at risk. A decade of USGS research on storm-driven coastal change hazards has provided the data and modeling capabilities to identify areas of our coastline that are likely to experience extreme and potentially hazardous erosion during a hurricane. This report defines hurricane-induced coastal erosion hazards for sandy beaches along the U.S. Gulf of Mexico coastline. The analysis is based on a storm-impact scaling model that uses observations of beach morphology combined with sophisticated hydrodynamic models to predict how the coast will respond to the direct landfall of category 1-5 hurricanes. Hurricane-induced water levels, due to both surge and waves, are compared to beach and dune elevations to determine the probabilities of three types of coastal change: collision (dune erosion), overwash, and inundation. As new beach morphology observations and storm predictions become available, this analysis will be updated to describe how coastal vulnerability to storms will vary in the future.

  9. Hurricanes in an Aquaplanet World: Implications of the Impacts of External Forcing and Model Horizontal Resolution

    Energy Technology Data Exchange (ETDEWEB)

    Li, Fuyu; Collins, William D.; Wehner, Michael F.; Leung, Lai-Yung R.

    2013-06-02

    High-resolution climate models have been shown to improve the statistics of tropical storms and hurricanes compared to low-resolution models. The impact of increasing horizontal resolution in the tropical storm simulation is investigated exclusively using a series of Atmospheric Global Climate Model (AGCM) runs with idealized aquaplanet steady-state boundary conditions and a fixed operational storm-tracking algorithm. The results show that increasing horizontal resolution helps to detect more hurricanes, simulate stronger extreme rainfall, and emulate better storm structures in the models. However, increasing model resolution does not necessarily produce stronger hurricanes in terms of maximum wind speed, minimum sea level pressure, and mean precipitation, as the increased number of storms simulated by high-resolution models is mainly associated with weaker storms. The spatial scale at which the analyses are conducted appears to have more important control on these meteorological statistics compared to horizontal resolution of the model grid. When the simulations are analyzed on common low-resolution grids, the statistics of the hurricanes, particularly the hurricane counts, show reduced sensitivity to the horizontal grid resolution and signs of scale invariant.

  10. Dynamics of the chemical composition of rainwater throughout Hurricane Irene

    Directory of Open Access Journals (Sweden)

    K. M. Mullaugh

    2013-03-01

    Full Text Available Sequential sampling of rainwater from Hurricane Irene was carried out in Wilmington, NC, USA on 26 and 27 August 2011. Eleven samples were analyzed for pH, major ions (Cl−, NO3−, SO42−, Na+, K+, Mg2+, Ca2+, NH4+, dissolved organic carbon (DOC and hydrogen peroxide (H2O2. Hurricane Irene contributed 16% of the total rainwater and 18% of the total chloride wet deposition received in Wilmington NC during all of 2011. This work highlights the main physical factors influencing the chemical composition of tropical storm rainwater: wind speed, wind direction, back trajectory and vertical mixing, time of day and total rain volume. Samples collected early in the storm, when winds blew out of the east, contained dissolved components indicative of marine sources (salts from sea spray and low DOC. The sea-salt components in the samples had two maxima in concentration during the storm the first of which occurred before the volume of rain had sufficiently washed out sea salt from the atmosphere and the second when back trajectories showed large volumes of marine surface air were lifted. As the storm progressed and winds shifted to a westerly direction, the chemical composition of the rainwater became characteristic of terrestrial storms (high DOC and NH4+ and low sea salt. This work demonstrates that tropical storms are not only responsible for significant wet deposition of marine components to land, but terrestrial components can also become entrained in rainwater, which can then be delivered to coastal waters via wet deposition. This study also underscores why analysis of one composite sample can lead to an incomplete interpretation of the factors that influence the chemically divergent analytes in rainwater during extreme weather events.

  11. African Dust Influence on Atlantic Hurricane Activity and the Peculiar Behaviour of Category 5 Hurricanes

    CERN Document Server

    Herrera, Victor M Velasco; H., Graciela Velasco; Gonzalez, Laura Luna

    2010-01-01

    We study the specific influence of African dust on each one of the categories of Atlantic hurricanes. By applying wavelet analysis, we find a strong decadal modulation of African dust on Category 5 hurricanes and an annual modulation on all other categories of hurricanes. We identify the formation of Category 5 hurricanes occurring mainly around the decadal minimum variation of African dust and in deep water areas of the Atlantic Ocean, where hurricane eyes have the lowest pressure. According to our results, future tropical cyclones will not evolve to Category 5 until the next decadal minimum that is, by the year 2015 +/- 2.

  12. Post-disaster climatology for hurricanes and tornadoes in the United States: 2000-2009

    Science.gov (United States)

    Eakins, Benjamin James

    Natural disasters can be very devastating to the public during their impact phase. After a natural disaster impacts a region, the response and recovery phases begin immediately. Weather conditions may interrupt emergency response and recovery in the days following the disaster. This study analyzes the climatology of weather conditions during the response and recovery phases of hurricanes and tornadoes to understand how weather may impact both environment and societal needs. Using specific criteria, 66 tornadoes and 16 hurricane cases were defined. National Weather Service (NWS) recognized weather stations were used to provide temperature, precipitation, snowfall, relative humidity, wind speed, and wind direction data. Regional and temporal groups were defined for tornado cases, but only one group was defined for hurricanes. By applying statistical analysis to weather observations taken in the week following the disasters, a climatology was developed for the response and recovery phase. Tornado and hurricane post-disaster climate closely mimicked their synoptic climatology with cooler and drier weather prevailing in days 2-4 after a disaster until the next weather system arrived about 5 days later. Winter tornadoes trended to occur in the Southeast and were associated with more extreme temperature differences than in other regions and season. The results of this study may help governmental and non-governmental organizations prepare for weather conditions during the post-disaster phase.

  13. Bag-breakup control of surface drag in hurricanes

    Science.gov (United States)

    Troitskaya, Yuliya; Zilitinkevich, Sergej; Kandaurov, Alexander; Ermakova, Olga; Kozlov, Dmitry; Sergeev, Daniil

    2016-04-01

    Air-sea interaction at extreme winds is of special interest now in connection with the problem of the sea surface drag reduction at the wind speed exceeding 30-35 m/s. This phenomenon predicted by Emanuel (1995) and confirmed by a number of field (e.g., Powell, et al, 2003) and laboratory (Donelan et al, 2004) experiments still waits its physical explanation. Several papers attributed the drag reduction to spume droplets - spray turning off the crests of breaking waves (e.g., Kudryavtsev, Makin, 2011, Bao, et al, 2011). The fluxes associated with the spray are determined by the rate of droplet production at the surface quantified by the sea spray generation function (SSGF), defined as the number of spray particles of radius r produced from the unit area of water surface in unit time. However, the mechanism of spume droplets' formation is unknown and empirical estimates of SSGF varied over six orders of magnitude; therefore, the production rate of large sea spray droplets is not adequately described and there are significant uncertainties in estimations of exchange processes in hurricanes. Herewith, it is unknown what is air-sea interface and how water is fragmented to spray at hurricane wind. Using high-speed video, we observed mechanisms of production of spume droplets at strong winds by high-speed video filming, investigated statistics and compared their efficiency. Experiments showed, that the generation of the spume droplets near the wave crest is caused by the following events: bursting of submerged bubbles, generation and breakup of "projections" and "bag breakup". Statistical analysis of results of these experiments showed that the main mechanism of spray-generation is attributed to "bag-breakup mechanism", namely, inflating and consequent blowing of short-lived, sail-like pieces of the water-surface film. Using high-speed video, we show that at hurricane winds the main mechanism of spray production is attributed to "bag-breakup", namely, inflating and

  14. Image retrieval

    DEFF Research Database (Denmark)

    Ørnager, Susanne

    1997-01-01

    The paper touches upon indexing and retrieval for effective searches of digitized images. Different conceptions of what subject indexing means are described as a basis for defining an operational subject indexing strategy for images. The methodology is based on the art historian Erwin Panofsky...... of signs and connotation as meanings relating to feelings or associations. A joint methodology is suggested between the two researchers and the methodology is implemented in analyzing press photos. Fields of application discussed include the messages in an image and the linking between information running....... The empirical analysis demonstrates how the results can be applied as the foundation for a semantic model....

  15. Image retrieval

    DEFF Research Database (Denmark)

    Ørnager, Susanne

    1997-01-01

    The paper touches upon indexing and retrieval for effective searches of digitized images. Different conceptions of what subject indexing means are described as a basis for defining an operational subject indexing strategy for images. The methodology is based on the art historian Erwin Panofsky...... of signs and connotation as meanings relating to feelings or associations. A joint methodology is suggested between the two researchers and the methodology is implemented in analyzing press photos. Fields of application discussed include the messages in an image and the linking between information running...

  16. Increased Accuracy in Statistical Seasonal Hurricane Forecasting

    Science.gov (United States)

    Nateghi, R.; Quiring, S. M.; Guikema, S. D.

    2012-12-01

    Hurricanes are among the costliest and most destructive natural hazards in the U.S. Accurate hurricane forecasts are crucial to optimal preparedness and mitigation decisions in the U.S. where 50 percent of the population lives within 50 miles of the coast. We developed a flexible statistical approach to forecast annual number of hurricanes in the Atlantic region during the hurricane season. Our model is based on the method of Random Forest and captures the complex relationship between hurricane activity and climatic conditions through careful variable selection, model testing and validation. We used the National Hurricane Center's Best Track hurricane data from 1949-2011 and sixty-one candidate climate descriptors to develop our model. The model includes information prior to the hurricane season, i.e., from the last three months of the previous year (Oct. through Dec.) and the first five months of the current year (January through May). Our forecast errors are substantially lower than other leading forecasts such as that of the National Oceanic and Atmospheric Administration (NOAA).

  17. Gulf Coast Hurricanes Situation Report #39

    Energy Technology Data Exchange (ETDEWEB)

    None

    2005-11-09

    There are 49,300 customers without power in Florida as of 7:00 AM EST 11/9 due to Hurricane Wilma, down from a peak of about 3.6 million customers. Currently, less than 1 percent of the customers are without power in the state. This is the last report we will due on outages due to Hurricane Wilma.

  18. Hurricane impacts on US forest carbon sequestration

    Science.gov (United States)

    Steven G. McNulty

    2002-01-01

    Recent focus has been given to US forests as a sink for increases in atmospheric carbon dioxide. Current estimates of US Forest carbon sequestration average approximately 20 Tg (i.e. 1012 g) year. However, predictions of forest carbon sequestration often do not include the influence of hurricanes on forest carbon storage. Intense hurricanes...

  19. Upper Ocean Responses to Hurricane Frances in September 2004

    Science.gov (United States)

    Sanford, T. B.; Price, J. F.; Webb, D. C.; Girton, J. B.

    2007-05-01

    Three new autonomous ocean velocity and density profilers were deployed ahead of Hurricane Frances as it passed north of Hispaniola in September 2004. These EM-APEX floats (velocity sensing versions of Webb Research Corp APEX floats) were launched from a C-130. The EM-APEX floats measured T, S and V over the upper 500 m starting about a day before the storm's arrival. One EM-APEX float was directly under the track of the storm's eye, another EM-APEX float went in about 55 km to the right of the track (where the surface winds are strongest) and the third float was about 110 km to the right. The EM-APEX floats profiled for 10 hours from the surface to 200 m then continued profiling between 30 and 200 m with excursions to 500 m every half inertial period. After 5 days, the EM-APEX floats surfaced and transmitted the accumulated processed observations, then the floats profiled to 500 m every half inertial period until recovered early in October aided by GPS and Iridium. The float array sampled in unprecedented detail the upper-ocean momentum, turbulence and salt and heat changes in response to the hurricane. Rapid acceleration of inertial currents in the surface mixing layer (SML) to over 1 m/s produced vertical mixing by shear instability at the SML base, as indicated by low Richardson numbers and SML deepening from about 40 m to 120 m under the strongest wind forcing. Surface cooling of about 2.2 C was primarily due to the SML deepening and entrainment of colder water, with a small contribution from surface heat flux. Intense inertial pumping was observed under the eye, with vertical excursions of 50 m or more. Comparison with a 3-D numerical model of the ocean response to Frances' winds simulates accurately SML deepening and surface cooling as well as significant differences in maximum currents and heat content changes. These differences highlight the sensitivity of the ocean's response to both the specification of the wind field and the parameterization of stress

  20. Genesis of tornadoes associated with hurricanes

    Science.gov (United States)

    Gentry, R. C.

    1983-01-01

    The climatological history of hurricane-tornadoes is brought up to date through 1982. Most of the tornadoes either form near the center of the hurricane, from the outer edge of the eyewall outward, or in an area between north and east-southeast of the hurricane center. The blackbody temperatures of the cloud tops which were analyzed for several hurricane-tornadoes that formed in the years 1974, 1975, and 1979, did not furnish strong precursor signals of tornado formation, but followed one of two patterns: either the temperatures were very low, or the tornado formed in areas of strong temperature gradients. Tornadoes with tropical cyclones most frequently occur at 1200-1800 LST, and although most are relatively weak, they can reach the F3 intensity level. Most form in association with the outer rainbands of the hurricane.

  1. Hurricane Katrina deaths, Louisiana, 2005.

    Science.gov (United States)

    Brunkard, Joan; Namulanda, Gonza; Ratard, Raoult

    2008-12-01

    Hurricane Katrina struck the US Gulf Coast on August 29, 2005, causing unprecedented damage to numerous communities in Louisiana and Mississippi. Our objectives were to verify, document, and characterize Katrina-related mortality in Louisiana and help identify strategies to reduce mortality in future disasters. We assessed Hurricane Katrina mortality data sources received in 2007, including Louisiana and out-of-state death certificates for deaths occurring from August 27 to October 31, 2005, and the Disaster Mortuary Operational Response Team's confirmed victims' database. We calculated age-, race-, and sex-specific mortality rates for Orleans, St Bernard, and Jefferson Parishes, where 95% of Katrina victims resided and conducted stratified analyses by parish of residence to compare differences between observed proportions of victim demographic characteristics and expected values based on 2000 US Census data, using Pearson chi square and Fisher exact tests. We identified 971 Katrina-related deaths in Louisiana and 15 deaths among Katrina evacuees in other states. Drowning (40%), injury and trauma (25%), and heart conditions (11%) were the major causes of death among Louisiana victims. Forty-nine percent of victims were people 75 years old and older. Fifty-three percent of victims were men; 51% were black; and 42% were white. In Orleans Parish, the mortality rate among blacks was 1.7 to 4 times higher than that among whites for all people 18 years old and older. People 75 years old and older were significantly more likely to be storm victims (P Hurricane Katrina was the deadliest hurricane to strike the US Gulf Coast since 1928. Drowning was the major cause of death and people 75 years old and older were the most affected population cohort. Future disaster preparedness efforts must focus on evacuating and caring for vulnerable populations, including those in hospitals, long-term care facilities, and personal residences. Improving mortality reporting timeliness will

  2. Retrieval of chlorphyll from the sea-leaving radiance in the Arbaian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Sathe, P.V.; Jadhav, N.

    Error estimates in chlorophyll retrieval in the sea from satellite data have always been higher compared to the errors in retrieval of sea surface temperature or wind speed from satellite data. This is due to the higher percentage of noise...

  3. Effect of Coupling Wave and Flow Dynamics on Hurricane Surge and Inundation

    Science.gov (United States)

    2012-01-01

    impacted hurricanes - both by the wind fields as well as by the accompanying surge. Forecasting the extent of the inundation is critical for local...estimate local surge hazards; and in the other, ensemble model runs are used to determine surge values from a set of parameterized storms [Irish et...with the storm surge to create the storm tide. The extent of coastal inundation - flooding of inland surface that is not normally submerged, is

  4. Large-scale Vertical Motions, Intensity Change and Precipitation Associated with Land falling Hurricane Katrina over the Gulf of Mexico

    Science.gov (United States)

    Reddy, S. R.; Kwembe, T.; Zhang, Z.

    2016-12-01

    We investigated the possible relationship between the large- scale heat fluxes and intensity change associated with the landfall of Hurricane Katrina. After reaching the category 5 intensity on August 28th , 2005 over the central Gulf of Mexico, Katrina weekend to category 3 before making landfall (August 29th , 2005) on the Louisiana coast with the maximum sustained winds of over 110 knots. We also examined the vertical motions associated with the intensity change of the hurricane. The data for Convective Available Potential Energy for water vapor (CAPE), sea level pressure and wind speed were obtained from the Atmospheric Soundings, and NOAA National Hurricane Center (NHC), respectively for the period August 24 to September 3, 2005. We also computed vertical motions using CAPE values. The study showed that the large-scale heat fluxes reached maximum (7960W/m2) with the central pressure 905mb. The Convective Available Potential Energy and the vertical motions peaked 3-5 days before landfall. The large atmospheric vertical motions associated with the land falling hurricane Katrina produced severe weather including thunderstorm, tornadoes, storm surge and floods Numerical model (WRF/ARW) with data assimilations have been used for this research to investigate the model's performances on hurricane tracks and intensities associated with the hurricane Katrina, which began to strengthen until reaching Category 5 on 28 August 2005. The model was run on a doubly nested domain centered over the central Gulf of Mexico, with grid spacing of 90 km and 30 km for 6 hr periods, from August 28th to August 30th. The model output was compared with the observations and is capable of simulating the surface features, intensity change and track associated with hurricane Katrina.

  5. Case Study of Hurricane Felix (2007) Rapid Intensification

    Science.gov (United States)

    Colon-Pagan, I. C.; Davis, C. A.; Holland, G. J.

    2010-12-01

    The forecasting of tropical cyclones (TC) rapid intensification (RI) is one of the most challenging problems that the operational community experiences. Research advances leading to improvements in predicting this phenomenon would help government agencies make decisions that could reduce the impact on communities that are so often affected by these weather-related events. It has been proposed that TC RI is associated to various factors, including high sea-surface temperatures, weak vertical wind shear, and the ratio of inertial to static stability, which improves the conversion of diabatic heating into circulation. While a cyclone develops, the size of the region of high inertial stability (IS) decreases whereas the magnitude of IS increases. However, it’s unknown whether this is a favorable condition or a result of RI occurrences. The purpose of this research, therefore, is to determine if the IS follows, leads or changes in sync with the intensity change by studying Hurricane Felix (2007) RI phase. Results show a trend of increasing IS before the RI stage, followed by an expansion of the region of high IS. This episode is eventually followed by a decrease in both the intensity and region of positive IS, while the maximum wind speed intensity of the TC diminished. Therefore, we propose that monitoring the IS may provide a forecast tool to determine RI periods. Other parameters, such as static stability, tangential wind, and water vapor mixing ratio may help identify other features of the storm, such as circulation and eyewall formation. The inertial stability (IS) trend during the period of rapid intensification, which occurred between 00Z and 06Z of September 3rd. Maximum values of IS were calculated before and during this period of RI within a region located 30-45 km from the center. In fact, this region could represent the eye-wall of Hurricane Felix.

  6. Impact of the hurricanes Gustav and Ike in the karst areas of the Vi

    Science.gov (United States)

    Farfàn Gonzalez, H.; Corvea Porras, J. L.; Martinez Maquiera, Y.; Diaz Guanche, C.; Aldana Vilas, C.; de Bustamante, I.; Parise, M.

    2009-04-01

    Among the many natural hazards affecting the island of Cuba, the hydro-meteorological hazards include extreme rainstorms, tropical cyclones and hurricanes. At Cuba, as in the rest of the Caribbean Islands, the cyclonic period generally starts at the beginning of June and ends in late November; during this time period, hurricanes represent the most powerful expression of the tropical cyclones. As shown by historical data, the effects of hurricanes interest the whole island, with a particular focus at its western regions. Intensity of these events causes severe damage to the environment and the society. Hurricanes are classified into five categories according to the Saffir-Simpson Hurricane Scale, essentially on the basis of the velocity reached by the winds. In this scale, category I is the less intense, and V the highest. In 2008, two strong hurricanes affected the province of Pinar del Rio, in western Cuba, during August and September, with a 10-days interval between the two events. Many effects were produced by the passage of the hurricanes, especially in the karst areas of the Viñales National Park. The first hurricane (named Gustavo) was registered on August 30, 2008. Classified as category IV, it hit the area with wind velocities over 250 km/h, gusts over 300 km/h, and a total rainfall of approximately 100 mm. The hurricane affected the southern slope of the area of mogotes, that is the isolated cone or tower left by intense development of karst processes in tropical climate conditions. The vegetation cover was strongly hit, and largely stripped away, thus exposing several situations of hazards in karst that were previously undetected. Local flooding was also recorded, generally in the lowest topographic areas, and with short duration, due to bedrock characteristics. Ten days after Gustavo, the second hurricane (named Ike) affected the whole Cuba on September 9, 2008. Even though classified as category I, it caused severe damage to the man-made environment

  7. An Examination of Hurricane Emergency Preparedness Planning at Institutions of Higher Learning of the Gulf South Region Post Hurricane Katrina

    Science.gov (United States)

    Ventura, Caterina Gulli

    2010-01-01

    The purpose of the study was to examine hurricane emergency preparedness planning at institutions of higher learning of the Gulf South region following Hurricane Katrina. The problem addressed the impact of Hurricane Katrina on decision-making and policy planning processes. The focus was on individuals that administer the hurricane emergency…

  8. An Examination of Hurricane Emergency Preparedness Planning at Institutions of Higher Learning of the Gulf South Region Post Hurricane Katrina

    Science.gov (United States)

    Ventura, Caterina Gulli

    2010-01-01

    The purpose of the study was to examine hurricane emergency preparedness planning at institutions of higher learning of the Gulf South region following Hurricane Katrina. The problem addressed the impact of Hurricane Katrina on decision-making and policy planning processes. The focus was on individuals that administer the hurricane emergency…

  9. 78 FR 31614 - Implementation of Regulatory Guide 1.221 on Design-Basis Hurricane and Hurricane Missiles

    Science.gov (United States)

    2013-05-24

    ....221 on Design-Basis Hurricane and Hurricane Missiles AGENCY: Nuclear Regulatory Commission. ACTION... guidance regarding the application of Regulatory Guide (RG) 1.221, ``Design-Basis Hurricane and Hurricane... ML13015A688 Interim Staff Guidance-024 on Implementation of Regulatory Guide 1.221 on Design-Basis...

  10. Hurricane Katrina and perinatal health.

    Science.gov (United States)

    Harville, Emily W; Xiong, Xu; Buekens, Pierre

    2009-12-01

    We review the literature on the effects of Hurricane Katrina on perinatal health, and providing data from our own research on pregnant and postpartum women. After Katrina, obstetric, prenatal, and neonatal care was compromised in the short term, but increases in adverse birth outcomes such as preterm birth, low birthweight, and maternal complications were mostly limited to highly exposed women. Both pregnant and postpartum women had rates of post-traumatic stress disorder similar to, or lower than, others exposed to Katrina, and rates of depression similar to other pregnant and postpartum populations. Health behaviors, such as smoking and breastfeeding, may have been somewhat negatively affected by the disaster, whereas effects on nutrition were likely associated with limited time, money, and food choices, and indicated by both weight gain and loss. We conclude that, with a few specific exceptions, postdisaster concerns and health outcomes for pregnant and postpartum women were similar to those of other people exposed to Hurricane Katrina. In such situations, disaster planners and researchers should focus on providing care and support for the normal concerns of the peripartum period, such as breastfeeding, depression, and smoking cessation. Contraception needs to be available for those who do not want to become pregnant. Although additional physical and mental health care needs to be provided for the most severely exposed women and their babies, many women are capable of surviving and thriving in postdisaster environments.

  11. Hurricane related flooding monitoring: a method to delineate potentially affected areas by using a GIS model in the Caribbean area

    Science.gov (United States)

    Melelli, L.; Taramelli, A.; Sorichetta, A.; Pasqui, M.

    2007-12-01

    This research integrates the concept that the subject of natural hazards and the use of existing remote sensing systems in the different phases of a disaster management for a specific hurricane hazard, is based on the applicability of GIS model for increasing preparedness and providing early warning. The modelling of an hurricane event in potentially affected areas by GIS has recently become a major topic of research. In this context the disastrous effects of hurricanes on coastal communities and surroundings areas are well known, but there is a need to better understand the causes and the hazards contributions of the different events related to an hurricane, like storm surge, flooding and high winds. This blend formed the basis of a semi- quantitative and promising approach in order to model the spatial distribution of the final hazard along the affected areas. The applied model determines a sudden onset zoning from a set of available parameters starting from topography based on Shuttle Radar Topography Mission (SRTM) data. From the Digital Elevation Model as a first step the river network is derived and then classified based on the Strahler order account as proportional to flooding area. Then we use a hydrologic model that uses the wetness index (a parameter of specific catchment area defined as upslope area per unit contour length) to better quantify the drainage area that contributes to the flooded events. Complementary data for the final model includes remote sensed density rain dataset for the hurricane events taking into account and existing hurricane tracks inventories together with hurricane structure model (different buffers related to wind speed hurricane parameters in a GIS environment). To assess the overall susceptibility, the hazard results were overlaid with population dataset and landcover. The approach, which made use of a number of available global data sets, was then validated on a regional basis using past experience on hurricane frequency

  12. Prototype of an Integrated Hurricane Information System for Research: Design and Implementation of the Database and Web Portal

    Science.gov (United States)

    Li, P. P.; Knosp, B.; Vu, Q. A.; Hristova-Veleva, S.; Chao, Y.; Vane, D.; Lambrigtsen, B.; Su, H.; Dang, V.; Fovell, R.; Willis, J.; Tanelli, S.; Fishbein, E.; Ao, C. O.; Poulsen, W. L.; Park, K. J.; Fetzer, E.; Vazquez, J.; Callahan, P. S.; Marcus, S.; Garay, M.; Kahn, R.; Haddad, Z.

    2007-12-01

    Many hurricane websites provide historical hurricane information and real-time storm tracking. These sites often include images from various remote-sensing satellite sensors with such atmospheric and oceanic quantities as wind, temperature, rain, and water vapor. However, it has been determined that the hurricane analysis community is lacking a web portal that provides researchers a comprehensive set of observed hurricane parameters (both graphics and data) together with large-scale and convection-resolving model output. We have developed a prototype of an integrated hurricane information system of high-resolution satellite and in- situ observations along with model outputs pertaining to: i) the thermodynamic and microphysical structure of storms; ii) the air-sea interaction processes; iii) the larger-scale environment as depicted by quantities such as SST, ocean heat content and the aerosol loading of the environment. Our goal is to provide a one-stop place to access all the available information of a specific hurricane for researchers to advance the understanding, modeling and predication of hurricane genesis and intensity changes. Our hurricane information system prototype consists of high-resolution satellite data measuring three- dimensional atmospheric and oceanic parameters that includes observations from AIRS, MISR, MODIS, CloudSAT, AMSR-E, TRMM, GOES, MLS, QuikSCAT, SeaWiFS, and COSMIC GPS, in-situ observations such as ARGO floats, large scale data assimilation products from NCEP, and high resolution hurricane model output from WRF. High-resolution satellite data are sub-setted within 2000-kilometer-square area centered at the closest storm location and large-scale environmental datasets are divided into 6 predefined geographical regions. When accessing this hurricane portal, users may browse through data by year, region, category, and hurricane. At the front page, we show the hurricane track using Google Map. Users may pan and zoom, or click on the track

  13. Recovery from PTSD following Hurricane Katrina.

    Science.gov (United States)

    McLaughlin, Katie A; Berglund, Patricia; Gruber, Michael J; Kessler, Ronald C; Sampson, Nancy A; Zaslavsky, Alan M

    2011-06-01

    We examined patterns and correlates of speed of recovery of estimated posttraumatic stress disorder (PTSD) among people who developed PTSD in the wake of Hurricane Katrina. A probability sample of prehurricane residents of areas affected by Hurricane Katrina was administered a telephone survey 7-19 months following the hurricane and again 24-27 months posthurricane. The baseline survey assessed PTSD using a validated screening scale and assessed a number of hypothesized predictors of PTSD recovery that included sociodemographics, prehurricane history of psychopathology, hurricane-related stressors, social support, and social competence. Exposure to posthurricane stressors and course of estimated PTSD were assessed in a follow-up interview. An estimated 17.1% of respondents had a history of estimated hurricane-related PTSD at baseline and 29.2% by the follow-up survey. Of the respondents who developed estimated hurricane-related PTSD, 39.0% recovered by the time of the follow-up survey with a mean duration of 16.5 months. Predictors of slow recovery included exposure to a life-threatening situation, hurricane-related housing adversity, and high income. Other sociodemographics, history of psychopathology, social support, social competence, and posthurricane stressors were unrelated to recovery from estimated PTSD. The majority of adults who developed estimated PTSD after Hurricane Katrina did not recover within 18-27 months. Delayed onset was common. Findings document the importance of initial trauma exposure severity in predicting course of illness and suggest that pre- and posttrauma factors typically associated with course of estimated PTSD did not influence recovery following Hurricane Katrina. © 2011 Wiley-Liss, Inc.

  14. 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.

  15. The influence of coastal wetlands on hurricane surge in Corpus Christi, TX

    Science.gov (United States)

    Ferreira, C.; Irish, J. L.; Olivera, F.

    2010-12-01

    The State of Texas has historically faced hurricane-related damage episodes, with Ike being the most recent example. It is expected that, in the future, hurricanes will intensify due to climate change causing greater surges, while the attenuating effect of wetlands on storm surges will also be modified due to sea level rise changes in wetland vegetation type and spatial location. Numerical analysis of storm surges is an important instrument to predict and simulate flooding extent and magnitude in coastal areas. Most operational surge models account for the influence of wetlands and other vegetation by momentum loss due to friction at the bottom and by reduction of imposed wind stress. A coupled hydrodynamic model (ADCIRC) and wave model (SWAN) was employed, and wetlands were characterized using Manning’s n, surface canopy, and surface roughness. The wetlands parameters were developed from: 1) the National Land Cover Dataset (NLCD) 1992 and 2001; 2) the National Wetlands Inventory (NWI) 2001. The calibrated coupled model for two historical hurricanes, Bret and Beulah, was used to simulate the storm surge for each scenario. Preliminary results for the sensitivity analyses, for hurricane Bret, comparing the scenarios with parameters developed from NLCD and NWI datasets with four hypothetical scenarios considering very high and low Manning’s n and wind stress (surface canopy) values showed that, for areas inside Nueces Bay, the storm surge high could vary up to four times depending on the parameter selection, for areas inside Corpus Christi Bay, the storm surge high varied around three times and behind the barrier island the storm surge high variation was less than three times. This study is a first step for an evaluation of the impact that sea level rise, climate changed wetlands, wetlands restoration, land use change, and wetlands degradation have on hurricane related surge elevation and extent in the city of Corpus Christi.

  16. The trauma signature of 2016 Hurricane Matthew and the psychosocial impact on Haiti

    Science.gov (United States)

    Shultz, James M.; Cela, Toni; Marcelin, Louis Herns; Espinola, Maria; Heitmann, Ilva; Sanchez, Claudia; Jean Pierre, Arielle; Foo, Cheryl YunnShee; Thompson, Kip; Klotzbach, Philip; Espinel, Zelde; Rechkemmer, Andreas

    2016-01-01

    ABSTRACT Background. Hurricane Matthew was the most powerful tropical cyclone of the 2016 Atlantic Basin season, bringing severe impacts to multiple nations including direct landfalls in Cuba, Haiti, Bahamas, and the United States. However, Haiti experienced the greatest loss of life and population disruption. Methods. An established trauma signature (TSIG) methodology was used to examine the psychological consequences of Hurricane Matthew in relation to the distinguishing features of this event. TSIG analyses described the exposures of Haitian citizens to the unique constellation of hazards associated with this tropical cyclone. A hazard profile, a matrix of psychological stressors, and a “trauma signature” summary for the affected population of Haiti - in terms of exposures to hazard, loss, and change - were created specifically for this natural ecological disaster. Results. Hazard characteristics of this event included: deluging rains that triggered mudslides along steep, deforested terrain; battering hurricane winds (Category 4 winds in the “eye-wall” at landfall) that dismantled the built environment and launched projectile debris; flooding “storm surge” that moved ashore and submerged villages on the Tiburon peninsula; and pummeling wave action that destroyed infrastructure along the coastline. Many coastal residents were left defenseless to face the ravages of the storm. Hurricane Matthew's slow forward progress as it remained over super-heated ocean waters added to the duration and degree of the devastation. Added to the havoc of the storm itself, the risks for infectious disease spread, particularly in relation to ongoing epidemics of cholera and Zika, were exacerbated. Conclusions. Hurricane Matthew was a ferocious tropical cyclone whose meteorological characteristics amplified the system's destructive force during the storm's encounter with Haiti, leading to significant mortality, injury, and psychological trauma.

  17. Comparative Sediment Transport Between Exposed and Reef Protected Beaches Under Different Hurricane Conditions

    Science.gov (United States)

    Miret, D.; Enriquez, C.; Marino-Tapia, I.

    2016-12-01

    Many world coast regions are subjected to tropical cyclone activity, which can cause major damage to beaches and infrastructure on sediment dominated coasts. The Caribbean Sea has on average 4 hurricanes per year, some of them have caused major damage to coastal cities in the past 25 years. For example, Wilma, a major hurricane that hit SE Mexico in October 2005 generated strong erosion at an exposed beach (Cancun), while beach accretion was observed 28 km south at a fringing reef protected beach (Puerto Morelos). Hurricanes with similar intensity and trajectory but different moving speeds have been reported to cause a different morphological response. The present study analyses the morphodynamic response to the hydrodynamic conditions of exposed and reef protected beaches, generated by hurricanes with similar intensities but different trajectories and moving speeds. A non-stationary Delft3D Wave model is used to generate large scale wind swell conditions and local sea wind states and coupled with Delft3D Flow model to study the connection between the continental shelf and surf zones exchanges. The model is validated with hydrodynamic data gathered during Wilma, and morphological conditions measured before and after the event. Preliminary results show that erosion appears at the exposed beach and a predominant exchange between north and south dominates the shelf sediment transport (figure 1). Onshore driven flows over the reef crest input sediment in the reef protected beach. It is expected that for a same track but faster moving speed, southward sediment transport will have less time to develop and accretion at the reef protected site would be less evident or inexistent. The study can be used as a prediction tool for shelf scale sediment transport exchange driven by hurricanes.

  18. The trauma signature of 2016 Hurricane Matthew and the psychosocial impact on Haiti.

    Science.gov (United States)

    Shultz, James M; Cela, Toni; Marcelin, Louis Herns; Espinola, Maria; Heitmann, Ilva; Sanchez, Claudia; Jean Pierre, Arielle; Foo, Cheryl YunnShee; Thompson, Kip; Klotzbach, Philip; Espinel, Zelde; Rechkemmer, Andreas

    2016-01-01

    Background. Hurricane Matthew was the most powerful tropical cyclone of the 2016 Atlantic Basin season, bringing severe impacts to multiple nations including direct landfalls in Cuba, Haiti, Bahamas, and the United States. However, Haiti experienced the greatest loss of life and population disruption. Methods. An established trauma signature (TSIG) methodology was used to examine the psychological consequences of Hurricane Matthew in relation to the distinguishing features of this event. TSIG analyses described the exposures of Haitian citizens to the unique constellation of hazards associated with this tropical cyclone. A hazard profile, a matrix of psychological stressors, and a "trauma signature" summary for the affected population of Haiti - in terms of exposures to hazard, loss, and change - were created specifically for this natural ecological disaster. Results. Hazard characteristics of this event included: deluging rains that triggered mudslides along steep, deforested terrain; battering hurricane winds (Category 4 winds in the "eye-wall" at landfall) that dismantled the built environment and launched projectile debris; flooding "storm surge" that moved ashore and submerged villages on the Tiburon peninsula; and pummeling wave action that destroyed infrastructure along the coastline. Many coastal residents were left defenseless to face the ravages of the storm. Hurricane Matthew's slow forward progress as it remained over super-heated ocean waters added to the duration and degree of the devastation. Added to the havoc of the storm itself, the risks for infectious disease spread, particularly in relation to ongoing epidemics of cholera and Zika, were exacerbated. Conclusions. Hurricane Matthew was a ferocious tropical cyclone whose meteorological characteristics amplified the system's destructive force during the storm's encounter with Haiti, leading to significant mortality, injury, and psychological trauma.

  19. The effect of proximity to hurricanes Katrina and Rita on subsequent hurricane outlook and optimistic bias.

    Science.gov (United States)

    Trumbo, Craig; Lueck, Michelle; Marlatt, Holly; Peek, Lori

    2011-12-01

    This study evaluated how individuals living on the Gulf Coast perceived hurricane risk after Hurricanes Katrina and Rita. It was hypothesized that hurricane outlook and optimistic bias for hurricane risk would be associated positively with distance from the Katrina-Rita landfall (more optimism at greater distance), controlling for historically based hurricane risk and county population density, demographics, individual hurricane experience, and dispositional optimism. Data were collected in January 2006 through a mail survey sent to 1,375 households in 41 counties on the coast (n = 824, 60% response). The analysis used hierarchal regression to test hypotheses. Hurricane history and population density had no effect on outlook; individuals who were male, older, and with higher household incomes were associated with lower risk perception; individual hurricane experience and personal impacts from Katrina and Rita predicted greater risk perception; greater dispositional optimism predicted more optimistic outlook; distance had a small effect but predicted less optimistic outlook at greater distance (model R(2) = 0.21). The model for optimistic bias had fewer effects: age and community tenure were significant; dispositional optimism had a positive effect on optimistic bias; distance variables were not significant (model R(2) = 0.05). The study shows that an existing measure of hurricane outlook has utility, hurricane outlook appears to be a unique concept from hurricane optimistic bias, and proximity has at most small effects. Future extension of this research will include improved conceptualization and measurement of hurricane risk perception and will bring to focus several concepts involving risk communication. © 2011 Society for Risk Analysis.

  20. Wind energy applications of synthetic aperture radar

    DEFF Research Database (Denmark)

    Badger, Merete

    Synthetic aperture radars (SAR), mounted on satellites or aircraft, have proven useful for ocean wind mapping. Wind speeds at the height 10 m may be retrieved from measurements of radar backscatter using empirical model functions. The resulting windfields are valuable in offshore wind energy...

  1. Hurricane risk assessment to rollback or ride out a cost versus loss decision making approach

    Science.gov (United States)

    Wohlman, Richard A.

    1992-01-01

    The potential exists that a hurricane striking the Kennedy Space Center while a Space Shuttle is on the pad. Winds in excess of 74.5 knots could cause the failure of the holddown bolts bringing about the catastrophic loss of the entire vehicle. Current plans call for the rollback of the shuttle when winds of that magnitude are forecast to strike the center. As this is costly, a new objective method for making rollback/rideout decisions based upon Bayesian Analysis and economic cost versus loss is presented.

  2. Ship Radar Observations of a Developing Hurricane in the East Pacific

    Science.gov (United States)

    Cifelli, Robert; Petersen, Walter A.; Boccippio, Dennis J.; Fairall, Chris W.; Rutledge, Steven A.; Arnold, James E. (Technical Monitor)

    2002-01-01

    During the recently completed East Pacific Investigation of Climate Processes in the Coupled Ocean-Atmosphere System (EPIC) field program, the NOAA research vessel Ronald H. Brown (RHB) was deployed in the east Pacific Inter Tropical Convergence Zone (ITCZ) for approximately 3 weeks near 10 deg. N, 95 deg. W. One of the principal objectives of the EPIC-ITCZ program was to observe the modulation of convection by synoptic-scale easterly waves and the air-sea coupling process in this poorly sampled region of the east Pacific. Data from the experiment will be used as validation to improve forecast models. The RHB carried a variety of platforms during EPIC to sample atmospheric and oceanic phenomena, including a scanning C-band Doppler radar, radiation flux instrumentation, air-sea flux system, Doppler lidar, 35 GHz cloud radar, UHF wind profiler, sea surface temperature (SST) sensors, as well as standard surface meteorological instrumentation and a suite of rain gauges. This presentation will focus on the analysis of C-band radar data that was collected on 10 September, 2001 as the ship passed through an easterly wave which later developed into hurricane Ivo. The ship captured approximately 12 hours of convection associated with the tropical disturbance. During this period, the domain sampled by the radar (approximately 71,000 sq km) contained a significant number of echo features. Specifically, the fraction of the domain containing radar echo above 10 dBZ reached 80% for over 2 hours and remained near 60% for a continuous six hour period. Animation of radar images showed distinct rotation in echo features associated with the easterly wave passage. Despite an approximate 4 C drop in surface air temperature and sustained winds approaching 20 m/ s, the SST remained nearly constant throughout the observation period (approx. 29.5 C). Peak values of latent and sensible heat flux exceeded 400 and 100 W /sq m, respectively. The radar documented the change in precipitation

  3. Effect of hurricanes and violent storms on salt marsh

    Science.gov (United States)

    Leonardi, N.; Ganju, N. K.; Fagherazzi, S.

    2016-12-01

    Salt marsh losses have been documented worldwide because of land use change, wave erosion, and sea-level rise. It is still unclear how resistant salt marshes are to extreme storms and whether they can survive multiple events without collapsing. Based on a large dataset of salt marsh lateral erosion rates collected around the world, here, we determine the general response of salt marsh boundaries to wave action under normal and extreme weather conditions. As wave energy increases, salt marsh response to wind waves remains linear, and there is not a critical threshold in wave energy above which salt marsh erosion drastically accelerates. We apply our general formulation for salt marsh erosion to historical wave climates at eight salt marsh locations affected by hurricanes in the United States. Based on the analysis of two decades of data, we find that violent storms and hurricanes contribute less than 1% to long-term salt marsh erosion rates. In contrast, moderate storms with a return period of 2.5 mo are those causing the most salt marsh deterioration. Therefore, salt marshes seem more susceptible to variations in mean wave energy rather than changes in the extremes. The intrinsic resistance of salt marshes to violent storms and their predictable erosion rates during moderate events should be taken into account by coastal managers in restoration projects and risk management plans.

  4. High-income does not protect against hurricane losses

    Science.gov (United States)

    Geiger, Tobias; Frieler, Katja; Levermann, Anders

    2016-08-01

    Damage due to tropical cyclones accounts for more than 50% of all meteorologically-induced economic losses worldwide. Their nominal impact is projected to increase substantially as the exposed population grows, per capita income increases, and anthropogenic climate change manifests. So far, historical losses due to tropical cyclones have been found to increase less than linearly with a nation’s affected gross domestic product (GDP). Here we show that for the United States this scaling is caused by a sub-linear increase with affected population while relative losses scale super-linearly with per capita income. The finding is robust across a multitude of empirically derived damage models that link the storm’s wind speed, exposed population, and per capita GDP to reported losses. The separation of both socio-economic predictors strongly affects the projection of potential future hurricane losses. Separating the effects of growth in population and per-capita income, per hurricane losses with respect to national GDP are projected to triple by the end of the century under unmitigated climate change, while they are estimated to decrease slightly without the separation.

  5. Hurricanes

    Science.gov (United States)

    ... Awareness Human Trafficking Awareness Month Holiday Stress Homeless Youth Awareness Month Bullying Prevention Domestic Violence Awareness Month Suicide Prevention Month/World Suicide Day Sept. 11th National ...

  6. Hurricane Katrina - Murphy Oil Spill Boundary

    Data.gov (United States)

    U.S. Environmental Protection Agency — Hurricane Katrina made landfall in August 2005, causing widespread devastation along the Gulf Coast of the United States. EPA emergency response personnel worked...

  7. Hurricane Sandy science plan: New York

    Science.gov (United States)

    Ransom, Clarice N.

    2013-01-01

    Hurricane Sandy is a stark reminder of why the Nation must become more resilient to coastal hazards. More than one-half of the U.S. population lives within 50 miles of a coast, and this number is increasing. The U.S. Geological Survey (USGS) is one of the largest providers of geologic and hydrologic information in the world. Federal, State, and local partners depend on the USGS science to know how to prepare for hurricane hazards and reduce losses from future hurricanes. The USGS works closely with other bureaus within the Department of the Interior, the Federal Emergency Management Agency, the National Oceanic Atmospheric Administration, the U.S. Army Corps of Engineers, the Environmental Protection Agency, and many State and local agencies to identify their information needs before, during, and after hurricanes.

  8. Evacuation Shelters - MDC_HurricaneShelter

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — A label feature class of Miami-Dade County Hurricane Evacuation Shelters (HEC) including Special Need Evacuation Centers (SNEC) and Medical Management Facilities...

  9. Tsunamis and Hurricanes A Mathematical Approach

    CERN Document Server

    Cap, Ferdinand

    2006-01-01

    Tsunamis and hurricanes have had a devastating impact on the population living near the coast during the year 2005. The calculation of the power and intensity of tsunamis and hurricanes are of great importance not only for engineers and meteorologists but also for governments and insurance companies. This book presents new research on the mathematical description of tsunamis and hurricanes. A combination of old and new approaches allows to derive a nonlinear partial differential equation of fifth order describing the steepening up and the propagation of tsunamis. The description includes dissipative terms and does not contain singularities or two valued functions. The equivalence principle of solutions of nonlinear large gas dynamics waves and of solutions of water wave equations will be used. An extension of the continuity equation by a source term due to evaporation rates of salt seawater will help to understand hurricanes. Detailed formula, tables and results of the calculations are given.

  10. Final Gulf Coast Hurricanes Situation Report #46

    Energy Technology Data Exchange (ETDEWEB)

    None

    2006-01-26

    According to Entergy New Orleans, electricity has been restored to the vast majority of residents and businesses in the city, except in a few isolated areas that sustained severe devastation from Hurricane Katrina.

  11. Hurricane Irene Poster (August 27, 2011)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hurricane Irene poster. Color composite GOES image shows Irene moving through the North Carolina Outer Banks on August 27, 2011. Poster size is 36"x27"

  12. Forecasting OctoberNovember Caribbean hurricane days

    National Research Council Canada - National Science Library

    Philip J. Klotzbach

    2011-01-01

      Late season Caribbean hurricane activity is predictable ENSO and the AWP show skill as predictors for OctNov Caribbean activity OctoberNovember Caribbean activity can significantly impact the US...

  13. Hurricane Katrina - Murphy Oil Spill Boundary

    Science.gov (United States)

    Hurricane Katrina made landfall in August 2005, causing widespread devastation along the Gulf Coast of the United States. EPA emergency response personnel worked with FEMA and state and local agencies to respond to the emergencies throughout the Gulf.

  14. Evacuation Shelters - MDC_HurricaneShelter

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — A label feature class of Miami-Dade County Hurricane Evacuation Shelters (HEC) including Special Need Evacuation Centers (SNEC) and Medical Management Facilities...

  15. Hurricane risk management and climate information gatekeeping in southeast Florida

    Science.gov (United States)

    Treuer, G.; Bolson, J.

    2013-12-01

    Tropical storms provide fresh water necessary for healthy economies and health ecosystems. Hurricanes, massive tropical storms, threaten catastrophic flooding and wind damage. Sea level rise exacerbates flooding risks from rain and storm surge for coastal communities. Climate change adaptation measures to manage this risk must be implemented locally, but actions at other levels of government and by neighboring communities impact the options available to local municipalities. When working on adaptation local decision makers must balance multiple types of risk: physical or scientifically described risks, legal risks, and political risks. Generating usable or actionable climate science is a goal of the academic climate community. To do this we need to expand our analysis to include types of risk that constrain the use of objective science. Integrating physical, legal, and political risks is difficult. Each requires specific expertise and uses unique language. An opportunity exists to study how local decision makers manage all three on a daily basis and how their risk management impacts climate resilience for communities and ecosystems. South Florida's particular vulnerabilities make it an excellent case study. Besides physical vulnerabilities (low elevation, intense coastal development, frequent hurricanes, compromised ecosystems) it also has unique legal and political challenges. Federal and state property rights protections create legal risks for government action that restricts land use to promote climate adaptation. Also, a lack of cases that deal with climate change creates uncertainty about the nature of these legal risks. Politically Florida is divided ideologically and geographically. The regions in the southeast which are most vulnerable are predominantly Hispanic and under-represented at the state level, where leadership on climate change is functionally nonexistent. It is conventional wisdom amongst water managers in Florida that little climate adaptation

  16. Hurricanes, coral reefs and rainforests: resistance, ruin and recovery in the Caribbean

    Science.gov (United States)

    2000-01-01

    The coexistence of hurricanes, coral reefs, and rainforests in the Caribbean demonstrates that highly structured ecosystems with great diversity can flourish in spite of recurring exposure to intense destructive energy. Coral reefs develop in response to wave energy and resist hurricanes largely by virtue of their structural strength. Limited fetch also protects some reefs from fully developed hurricane waves. While storms may produce dramatic local reef damage, they appear to have little impact on the ability of coral reefs to provide food or habitat for fish and other animals. Rainforests experience an enormous increase in wind energy during hurricanes with dramatic structural changes in the vegetation. The resulting changes in forest microclimate are larger than those on reefs and the loss of fruit, leaves, cover, and microclimate has a great impact on animal populations. Recovery of many aspects of rainforest structure and function is rapid, though there may be long-term changes in species composition. While resistance and repair have maintained reefs and rainforests in the past, human impacts may threaten their ability to survive.

  17. Landslides triggered by Hurricane Hugo in eastern Puerto Rico, September 1989

    Science.gov (United States)

    Larsen, Matthew C.; Torres-Sanchez, Angel J.

    1992-01-01

    On the morning of September 18, 1989, a category-four hurricane struck eastern Puerto Rico with a sustained wind speed in excess of 46 m/s. The 24-h rainfall accumulation from the hurricane ranged from 100 to 339 mm. Average rainfall intensities ranging from 34 to 39 mm/h were calculated for 4 and 6 h periods, respectively, at a rain gage equipped with satellite telemetry, and at an observer station. The hurricane rainfall triggered more than 400 landslides in the steeply sloping, highly dissected mountains of eastern Puerto Rico. Of these landslides, 285 were mapped from aerial photography which covered 6474 ha. Many of the mapped landslides were on northeast- and northwest-facing slopes at the eastern terminus of the mountains, nearest the hurricane path. The surface area of individual landslides ranged from 18 m2 to 4500 m2, with a median size of 148 m2. The 285 landslides disturbed 0.11% of the land surface in the area covered by aerial photographs. An approximate denudation rate of 164 mm/1000 y was calculated from the volume of material eroded by landsliding and the 10-y rainfall recurrence interval.

  18. [Injuries following a hurricane in Nordmøre].

    Science.gov (United States)

    Ranhoff, A H; Naustdal, H; Skomsvoll, J F

    1992-12-10

    In this article we describe the efforts of local authorities to detect and treat casualties caused by a hurricane that struck the west coast of Norway January 1st, 1992 and prevent further injuries. Wind velocity exceeded 100 knots (117 mph), the strongest ever recorded in Norway. The damage to buildings, trees and power lines was so devastating that the Nordmøre area, with approximately 50,000 inhabitants, was left without electricity for five days. Altogether 56 casualties were reported by physicians and the local hospital (one death, caused by hypothermia and exhaustion, and six admissions to hospital) in the period 1-5 January. Nine old people suffered injuries by falling in the dark in their houses, and ten men were injured during repair work.

  19. Turbulent flow over a house in a simulated hurricane boundary layer

    CERN Document Server

    Taylor, Zachary; Gurka, Roi; Kopp, Gregory

    2009-01-01

    Every year hurricanes and other extreme wind storms cause billions of dollars in damage worldwide. For residential construction, such failures are usually associated with roofs, which see the largest aerodynamic loading. However, determining aerodynamic loads on different portions of North American houses is complicated by the lack of clear load paths and non-linear load sharing in wood frame roofs. This problem of fluid-structure interaction requires both wind tunnel testing and full-scale structural testing. A series of wind tunnel tests have been performed on a house in a simulated atmospheric boundary layer (ABL), with the resulting wind-induced pressures applied to the full-scale structure. The ABL was simulated for flow over open country terrain where both velocity and turbulence intensity profiles, as well as spectra, were matched with available full scale measurements for this type of terrain. The first set of measurements was 600 simultaneous surface pressure measurements over the entire house. A key...

  20. Cloud Microphysics in Hurricane Outflows: Observations in 'Bonnie' (1998) at 12 km Altitude

    Science.gov (United States)

    Pueschel, Rudolf F.; Hallett, J.; Strawa, A. W.; Ferry, G. V.; Bui, T. P.; Condon, Estelle P. (Technical Monitor)

    2000-01-01

    The water balance of a hurricane is controlled by boundary layer inflow, near vertical motion in the eyewall causing coalescence precipitation at above and residual ice precipitation at below freezing temperatures, and cirrus outflow at below -40 C aloft. In this paper we address the question of efficiency of water removal by this cirrus outflow which is important for the release of latent heat at high altitudes and its role in the dynamic flow at that level. During NASA's 1998 Convection and Moisture Experiment campaign we acquired microphysical outflow data in order to (1) determine the release and redistribution of latent heat near the top of hurricanes, (2) aid in TRMM algorithm development for remote sensing of precipitation, and (3) determine the optical/radiative characteristics of hurricane outflow. The data were acquired with Particle Measuring Systems two dimensional imaging spectrometers. On 23 August and again during the hurricane's landfall on 26 August, 1998, the NASA DC-8 aircraft penetrated hurricane 'Bonnie' four times each near 200 hPa pressure altitude. The eye crossing times were determined by (1) zero counts of cloud particles, (2) approximately 5 C increases in static and potential temperatures, and (3) minima in speeds and changes of direction of horizontal winds. The vertical winds showed shear between -6 m per second and +4 m per second and tangential winds approached 30 m per second in the eyewall. The particle volumes in the eyewall (determined by the pixels the particles shadowed in the direction of flight [x-direction] and normally to it by the number of diodes that they shadowed [y-direction]) ranged between 0.5 and 5.0 cubic centimeters per cubic meter. With a particle density near 0.2 g per cubic centimeter (determined from in situ melting and evaporation on a surface collector), the 1.0 g per meter corresponding mass of cloud ice ranged between 0.27 and 2.7 g per kilograms yielding horizontal fluxes between 8.1 and 81 g per square

  1. A space-time statistical climate model for hurricane intensification in the North Atlantic basin

    Science.gov (United States)

    Fraza, Erik; Elsner, James B.; Jagger, Thomas H.

    2016-08-01

    Climate influences on hurricane intensification are investigated by averaging hourly intensification rates over the period 1975-2014 in 8° × 8° latitude-longitude grid cells. The statistical effects of hurricane intensity and sea-surface temperature (SST), along with the climatic effects of El Niño-Southern Oscillation (ENSO), the North Atlantic Oscillation (NAO) and the Madden-Julian Oscillation (MJO), are quantified using a Bayesian hierarchical model fit to the averaged data. As expected, stronger hurricanes tend to have higher intensification rates, especially over the warmest waters. Of the three climate variables considered, the NAO has the largest effect on intensification rates after controlling for intensity and SST. The model shows an average increase in intensification rates of 0.18 [0.06, 0.31] m s-1 h-1 (95 % credible interval) for every 1 standard deviation decrease in the NAO index. Weak trade winds associated with the negative phase of the NAO might result in less vertical wind shear and thus higher mean intensification rates.

  2. CYGNSS Spaceborne Constellation for Ocean Surface Winds: Mission Design and Sampling Properties

    Science.gov (United States)

    Ruf, Chris; Ridley, Aaron; Clarizia, Maria Paola; Gleason, Scott; Rose, Randall; Scherrer, John

    2014-05-01

    analogous to the sampling that would result from 32 simultaneous hurricane hunter aircraft making measurements of the wind speed directly below each aircraft. The temporal sampling is best described by a probability distribution of the revisit time at each location within the +/- 35o latitude coverage area. The median value of the revisit time is ~2 hours and the mean revisit time is ~6 hours. The bistatic radar cross section of the ocean surface at the specular reflection point between a GPS transmitter and a CYGNSS receiver is measured in the form of Delay-Doppler Maps (DDMs). Wind speed is estimated from the DDMs using a minimum variance (MV) estimator. The MV estimator is a composite of wind estimates obtained from different observables that can be derived from the DDMs. Regression-based wind retrievals are developed for each observable using geophysical model functions that relate an observable to the surface wind speed. The MV estimator exploits the partial decorrelation that is present between residual errors in each individual wind retrieval. The EGU 2014 presentation will include a summary of the current mission design, including the DDMI science payload, the spacecraft, the constellation orbital architecture, the mission concept of operations. The spatial and temporal sampling properties, and retrieval uncertainty, of the CYGNSS ocean surface wind measurements will also be presented.

  3. Automatic urban debris zone extraction from post-hurricane very high-resolution satellite and aerial imagery

    Directory of Open Access Journals (Sweden)

    Shasha Jiang

    2016-05-01

    Full Text Available Automated remote sensing methods have not gained widespread usage for damage assessment after hurricane events, especially for low-rise buildings, such as individual houses and small businesses. Hurricane wind, storm surge with waves, and inland flooding have unique damage signatures, further complicating the development of robust automated assessment methodologies. As a step toward realizing automated damage assessment for multi-hazard hurricane events, this paper presents a mono-temporal image classification methodology that quickly and accurately differentiates urban debris from non-debris areas using post-event images. Three classification approaches are presented: spectral, textural, and combined spectral–textural. The methodology is demonstrated for Gulfport, Mississippi, using IKONOS panchromatic satellite and NOAA aerial colour imagery collected after 2005 Hurricane Katrina. The results show that multivariate texture information significantly improves debris class detection performance by decreasing the confusion between debris and other land cover types, and the extracted debris zone accurately captures debris distribution. Additionally, the extracted debris boundary is approximately equivalent regardless of imagery type, demonstrating the flexibility and robustness of the debris mapping methodology. While the test case presents results for hurricane hazards, the proposed methodology is generally developed and expected to be effective in delineating debris zones for other natural hazards, including tsunamis, tornadoes, and earthquakes.

  4. Investigating the sensitivity of hurricane intensity and trajectory to sea surface temperatures using the regional model WRF

    Directory of Open Access Journals (Sweden)

    Cevahir Kilic

    2013-12-01

    Full Text Available The influence of sea surface temperature (SST anomalies on the hurricane characteristics are investigated in a set of sensitivity experiments employing the Weather Research and Forecasting (WRF model. The idealised experiments are performed for the case of Hurricane Katrina in 2005. The first set of sensitivity experiments with basin-wide changes of the SST magnitude shows that the intensity goes along with changes in the SST, i.e., an increase in SST leads to an intensification of Katrina. Additionally, the trajectory is shifted to the west (east, with increasing (decreasing SSTs. The main reason is a strengthening of the background flow. The second set of experiments investigates the influence of Loop Current eddies idealised by localised SST anomalies. The intensity of Hurricane Katrina is enhanced with increasing SSTs close to the core of a tropical cyclone. Negative nearby SST anomalies reduce the intensity. The trajectory only changes if positive SST anomalies are located west or north of the hurricane centre. In this case the hurricane is attracted by the SST anomaly which causes an additional moisture source and increased vertical winds.

  5. 2005 Significant U.S. Hurricane Strikes Poster

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 2005 Significant U.S. Hurricane Strikes poster is one of two special edition posters for the Atlantic Hurricanes. This beautiful poster contains two sets of...

  6. Tracks of Major Hurricanes of the Western Hemisphere

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 36"x24" National Hurricane Center poster depicts the complete tracks of all major hurricanes in the north Atlantic and eastern north Pacific basins since as...

  7. Identification of Caribbean basin hurricanes from Spanish documentary sources

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Herrera, R. [Depto. Fisica de la Tierra II, Facultad de Ciencias Fisicas, Universidad Complutense de Madrid, Ciudad Universitaria, 28040 Madrid (Spain); Gimeno, L. [Universidad de Vigo, Ourense (Spain); Ribera, P.; Gonzalez, E.; Fernandez, G. [Universidad Pablo de Olavide, Sevilla (Spain); Hernandez, E. [Universidad Complutense de Madrid, Madrid (Spain)

    2007-07-15

    This paper analyses five hurricanes that occurred in the period 1600 to 1800. These examples were identified during a systematic search in the General Archive of the Indies (AGI) in Seville. The research combined the expertise of climatologists and historians in order to optimise the search and analysis strategies. Results demonstrate the potential of this archive for the assessment of hurricanes in this period and show some of the difficulties involved in the collection of evidence of hurricane activity. The documents provide detailed descriptions of a hurricane's impacts and allow us to identify previously unreported hurricanes, obtain more precise dates for hurricanes previously identified, better define the area affected by a given hurricane and, finally, better assess a hurricane's intensity.

  8. Continental United States Hurricane Strikes 1950-2012

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Continental U.S. Hurricane Strikes Poster is our most popular poster which is updated annually. The poster includes all hurricanes that affected the U.S. since...

  9. National assessment of hurricane-induced coastal erosion hazards: Southeast Atlantic Coast

    Science.gov (United States)

    Stockdon, Hilary F.; Doran, Kara S.; Thompson, David M.; Sopkin, Kristin L.; Plant, Nathaniel G.

    2013-01-01

    Beaches serve as a natural barrier between the ocean and inland communities, ecosystems, and natural resources. However, these dynamic environments move and change in response to winds, waves, and currents. During extreme storms, changes to beaches can be large, and the results are sometimes catastrophic. Lives may be lost, communities destroyed, and millions of dollars spent on rebuilding. During storms, large waves may erode beaches, and high storm surge shifts the erosive force of the waves higher on the beach. In some cases, the combined effects of waves and surge may cause overwash or flooding. Building and infrastructure on or near a dune can be undermined during wave attack and subsequent erosion. During Hurricane Ivan in 2004, a five-story condominium in Orange Beach, Alabama, collapsed after the sand dune supporting the foundation eroded. The September 1999 landfall of Hurricane Dennis caused erosion and undermining that destroyed roads, foundations, and septic systems. Waves overtopping a dune can transport sand inland, covering roads and blocking evacuation routes or emergency relief. If storm surge inundates barrier island dunes, currents flowing across the island can create a breach, or new inlet, completely severing evacuation routes. Waves and surge during the 2003 landfall of Hurricane Isabel left a 200-meter (m) wide breach that cut the only road to and from the village of Hatteras, N.C. Extreme coastal changes caused by hurricanes may increase the vulnerability of communities both during a storm and to future storms. For example, when sand dunes on a barrier island are eroded substantially, inland structures are exposed to storm surge and waves. Absent or low dunes also allow water to flow inland across the island, potentially increasing storm surge in the back bay, on the soundside of the barrier, and on the mainland. During Hurricane Isabel the protective sand dunes near the breach were completely eroded, increasing vulnerability to future

  10. Child mortality after Hurricane Katrina.

    Science.gov (United States)

    Kanter, Robert K

    2010-03-01

    Age-specific pediatric health consequences of community disruption after Hurricane Katrina have not been analyzed. Post-Katrina vital statistics are unavailable. The objectives of this study were to validate an alternative method to estimate child mortality rates in the greater New Orleans area and compare pre-Katrina and post-Katrina mortality rates. Pre-Katrina 2004 child mortality was estimated from death reports in the local daily newspaper and validated by comparison with pre-Katrina data from the Louisiana Department of Health. Post-Katrina child mortality rates were analyzed as a measure of health consequences. Newspaper-derived estimates of mortality rates appear to be valid except for possible underreporting of neonatal rates. Pre-Katrina and post-Katrina mortality rates were similar for all age groups except infants. Post-Katrina, a 92% decline in mortality rate occurred for neonates (Katrina decline in infant mortality rate exceeds the pre-Katrina discrepancy between newspaper-derived and Department of Health-reported rates. A declining infant mortality rate raises questions about persistent displacement of high-risk infants out of the region. Otherwise, there is no evidence of long-lasting post-Katrina excess child mortality. Further investigation of demographic changes would be of interest to local decision makers and planners for recovery after public health emergencies in other regions.

  11. Generic Hurricane Extreme Seas State

    DEFF Research Database (Denmark)

    Wehmeyer, Christof; Skourup, Jesper; Frigaard, Peter

    2012-01-01

    the US east coast and the Gulf of Mexico (1851 - 2009) and Japanese east coast (1951 -2009) form the basis for Weibull extreme value analyses to determine return period respective maximum wind speeds. Unidirectional generic sea state spectra are obtained by application of the empirical models...

  12. Aeroelastic Modeling of Offshore Turbines and Support Structures in Hurricane-Prone Regions (Poster)

    Energy Technology Data Exchange (ETDEWEB)

    Damiani, R.

    2014-03-01

    US offshore wind turbines (OWTs) will likely have to contend with hurricanes and the associated loading conditions. Current industry standards do not account for these design load cases (DLCs), thus a new approach is required to guarantee that the OWTs achieve an appropriate level of reliability. In this study, a sequentially coupled aero-hydro-servo-elastic modeling technique was used to address two design approaches: 1.) The ABS (American Bureau of Shipping) approach; and 2.) The Hazard Curve or API (American Petroleum Institute) approach. The former employs IEC partial load factors (PSFs) and 100-yr return-period (RP) metocean events. The latter allows setting PSFs and RP to a prescribed level of system reliability. The 500-yr RP robustness check (appearing in [2] and [3] upcoming editions) is a good indicator of the target reliability for L2 structures. CAE tools such as NREL's FAST and Bentley's' SACS (offshore analysis and design software) can be efficiently coupled to simulate system loads under hurricane DLCs. For this task, we augmented the latest FAST version (v. 8) to include tower aerodynamic drag that cannot be ignored in hurricane DLCs. In this project, a 6 MW turbine was simulated on a typical 4-legged jacket for a mid-Atlantic site. FAST-calculated tower base loads were fed to SACS at the interface level (transition piece); SACS added hydrodynamic and wind loads on the exposed substructure, and calculated mudline overturning moments, and member and joint utilization. Results show that CAE tools can be effectively used to compare design approaches for the design of OWTs in hurricane regions and to achieve a well-balanced design, where reliability levels and costs are optimized.

  13. Improving Our Understanding of Atlantic Hurricanes Through Knowledge of the Saharan Air Layer: Hope Or Hype?

    Science.gov (United States)

    Braun, Scott

    2009-01-01

    The existence of the Saharan air layer (SAL), a layer of warm, dry, dusty air frequently present over the tropical Atlantic Ocean, has long been appreciated. The nature of its impact on hurricanes remains unclear, with some researchers arguing that the SAL amplifies hurricane development and with others arguing that it inhibits it. The potential negative impacts of the SAL include 1) low-level vertical wind shear associated with the African easterly jet; 2) warm air aloft, which increases thermodynamic stability; and 3) dry air, which produces cold downdrafts. Some investigators have assumed the validity of these proposed negative influences and have frequently used them to explain the failure of individual storms to intensify or to explain the relative inactivity of recent hurricane seasons. Multiple NASA satellite data sets and National Centers for Environmental Prediction global analyses are used to characterize the SAL's properties and evolution in relation to developing hurricanes. The results will shows that neither jet--induced vertical wind shear nor warm SAL air (high stability) produce significant negative impacts on Atlantic storms. Dry air appears to be a key mechanism for SAL influence, but the presence of dry SAL air is not always a good indicator of whether a storm will weaken since many examples of intensifying storms surrounded by such dry air can be found. Idealized simulations will be used to evaluate the role of dry air. Finally, two case studies of supposedly "prime examples" of SAL influence will show that the negative influences of the SAL are perhaps too readily ascribed to individual storms that fail to reach their maximum potential intensity.

  14. 77 FR 74341 - Establishing the Hurricane Sandy Rebuilding Task Force

    Science.gov (United States)

    2012-12-14

    ... the Hurricane Sandy Rebuilding Task Force By the authority vested in me as President by the.... Hurricane Sandy made landfall on October 29, 2012, resulting in major flooding, extensive structural damage... assist the affected region. A disaster of Hurricane Sandy's magnitude merits a comprehensive...

  15. Increase in West Nile neuroinvasive disease after Hurricane Katrina.

    Science.gov (United States)

    Caillouët, Kevin A; Michaels, Sarah R; Xiong, Xu; Foppa, Ivo; Wesson, Dawn M

    2008-05-01

    After Hurricane Katrina, the number of reported cases of West Nile neuroinvasive disease (WNND) sharply increased in the hurricane-affected regions of Louisiana and Mississippi. In 2006, a >2-fold increase in WNND incidence was observed in the hurricane-affected areas than in previous years.

  16. Increase in West Nile Neuroinvasive Disease after Hurricane Katrina

    OpenAIRE

    Caillou?t, Kevin A.; Michaels, Sarah R.; Xiong, Xu; Foppa, Ivo; Wesson, Dawn M.

    2008-01-01

    After Hurricane Katrina, the number of reported cases of West Nile neuroinvasive disease (WNND) sharply increased in the hurricane-affected regions of Louisiana and Mississippi. In 2006, a >2-fold increase in WNND incidence was observed in the hurricane-affected areas than in previous years.

  17. Community College Re-Enrollment after Hurricane Katrina

    Science.gov (United States)

    Lowe, Sarah R.; Rhodes, Jean E.

    2013-01-01

    In this study, we explored predictors of community college re-enrollment after Hurricane Katrina among a sample of low-income women (N = 221). It was predicted that participants' pre-hurricane educational optimism would predict community college re-enrollment a year after the hurricane. The influence of various demographic and additional resources…

  18. Hurricane destructive power predictions based on historical storm and sea surface temperature data.

    Science.gov (United States)

    Bogen, Kenneth T; Jones, Edwin D; Fischer, Larry E

    2007-12-01

    Forecasting destructive hurricane potential is complicated by substantial, unexplained intraannual variation in storm-specific power dissipation index (PDI, or integrated third power of wind speed), and interannual variation in annual accumulated PDI (APDI). A growing controversy concerns the recent hypothesis that the clearly positive trend in North Atlantic Ocean (NAO) sea surface temperature (SST) since 1970 explains increased hurricane intensities over this period, and so implies ominous PDI and APDI growth as global warming continues. To test this "SST hypothesis" and examine its quantitative implications, a combination of statistical and probabilistic methods were applied to National Hurricane Center HURDAT best-track data on NAO hurricanes during 1880-2002, and corresponding National Oceanographic and Atmospheric Administration Extended Reconstruction SST estimates. Notably, hurricane behavior was compared to corresponding hurricane-specific (i.e., spatiotemporally linked) SST; previous similar comparisons considered only SST averaged over large NAO regions. Contrary to the SST hypothesis, SST was found to vary in a monthly pattern inconsistent with that of corresponding PDI, and to be at best weakly associated with PDI or APDI despite strong correlation with corresponding mean latitude (R(2)= 0.55) or with combined mean location and a approximately 90-year periodic trend (R(2)= 0.70). Over the last century, the lower 75% of APDIs appear randomly sampled from a nearly uniform distribution, and the upper 25% of APDIs from a nearly lognormal distribution. From the latter distribution, a baseline (SST-independent) stochastic model was derived predicting that over the next half century, APDI will not likely exceed its maximum value over the last half century by more than a factor of 1.5. This factor increased to 2 using a baseline model modified to assume SST-dependence conditioned on an upper bound of the increasing NAO SST trend observed since 1970. An

  19. The Department of Defense and Homeland Security relationship: Hurricane Katrina through Hurricane Irene.

    Science.gov (United States)

    Weaver, John Michael

    2015-01-01

    This research explored federal intervention with the particular emphasis on examining how a collaborative relationship between Department of Defense (DOD) and Homeland Security (DHS) led to greater effectiveness between these two federal departments and their subordinates (United States Northern Command and Federal Emergency Management Agency, respectively) during the preparation and response phases of the disaster cycle regarding US continental-based hurricanes. Through the application of a two-phased, sequential mixed methods approach, this study determined how their relationship has led to longitudinal improvements in the years following Hurricane Katrina, focusing on hurricanes as the primary unit of analysis.

  20. Hurricane Katrina: addictive behavior trends and predictors.

    Science.gov (United States)

    Beaudoin, Christopher E

    2011-01-01

    Post-disaster trends in alcohol consumption and cigarette smoking, as well as their predictors, were identified. Methods. Data from cross-sectional and panel surveys of African American adults in New Orleans, Louisiana, were used from before (2004: n = 1,867; 2005: n = 879) and after (2006a: n = 500; 2006b: n = 500) Hurricane Katrina. Alcohol consumption increased significantly from pre- to post-Hurricane Katrina, while cigarette smoking remained constant. In 2006, posttraumatic stress disorder (PTSD) was associated with cigarette smoking, whereas "news attention" and "provided social support" were inversely associated with cigarette smoking. "News attention" was also inversely associated with cigarette smoking frequency, while "neighborliness" was associated with alcohol consumption. In addition, the effects of PTSD on alcohol consumption were moderated by "neighborliness." In the wake of Hurricane Katrina, there were complex predictive processes of addictive behaviors involving PTSD, news information, and social capital-related measures.

  1. Evaluation of GPM candidate algorithms on hurricane observations

    Science.gov (United States)

    Le, M.; Chandrasekar, C. V.

    2012-12-01

    storms and hurricanes. In this paper, the performance of GPM candidate algorithms [2][3] to perform profile classification, melting region detection as well as drop size distribution retrieval for hurricane Earl will be presented. This analysis will be compared with other storm observations that are not tropical storms. The philosophy of the algorithm is based on the vertical characteristic of measured dual-frequency ratio (DFRm), defined as the difference in measured radar reflectivities at the two frequencies. It helps our understanding of how hurricanes such as Earl form and intensify rapidly. Reference [1] T. Iguchi, R. Oki, A. Eric and Y. Furuhama, "Global precipitation measurement program and the development of dual-frequency precipitation radar," J. Commun. Res. Lab. (Japan), 49, 37-45.2002. [2] M. Le and V. Chandrasekar, Recent updates on precipitation classification and hydrometeor identification algorithm for GPM-DPR, Geoscience science and remote sensing symposium, IGARSS'2012, IEEE International, Munich, Germany. [3] M. Le ,V. Chandrasekar and S. Lim, Microphysical retrieval from dual-frequency precipitation radar board GPM, Geoscience science and remote sensing symposium, IGARSS'2010, IEEE International, Honolulu, USA.

  2. Measuring wind and stress under tropical cyclones with scatterometer

    Science.gov (United States)

    Liu, W. Timothy

    2016-07-01

    Ocean surface stress, the turbulent transport of momentum, is largely derived from wind through a drag coefficient. In tropical cyclones (TC), scatterometers have difficulty in measuring strong wind and there is large uncertainty in the drag coefficient. We postulate that the microwave backscatter from ocean surface roughness, which is in equilibrium with local stress, does not distinguish weather systems. The reduced sensitivity of scatterometer wind retrieval algorithm under the strong wind is an air-sea interaction problem that is caused by a change in the behavior of the drag coefficient and not a sensor problem. Under this assumption, we applied a stress retrieval algorithm developed over a moderate wind range to retrieve stress under the strong winds of TCs. Over a moderate wind range, the abundant wind measurements and more established drag coefficient value allow sufficient stress data to be computed from wind to develop a stress retrieval algorithm for the scatterometer. Using unprecedented large amount of stress retrieved from the scatterometer coincident with strong winds in TC, we showed that the drag coefficient decreases with wind speed at a much steeper rate than previously revealed, for wind speeds over 25 m/s. The result implies that the ocean applies less drag to inhibit TC intensification and the TC causes less ocean mixing and surface cooling than previous studies indicated. With continuous and extensive coverage from constellations of scatterometers for several decades, the impact of tropical cyclones on the ocean and the feedback from the ocean are examined.

  3. Hurricane Modeling and Supercomputing: Can a global mesoscale model be useful in improving forecasts of tropical cyclogenesis?

    Science.gov (United States)

    Shen, B.; Tao, W.; Atlas, R.

    2007-12-01

    Hurricane modeling, along with guidance from observations, has been used to help construct hurricane theories since the 1960s. CISK (conditional instability of the second kind, Charney and Eliassen 1964; Ooyama 1964,1969) and WISHE (wind-induced surface heat exchange, Emanuel 1986) are among the well-known theories being used to understand hurricane intensification. For hurricane genesis, observations have indicated the importance of large-scale flows (e.g., the Madden-Julian Oscillation or MJO, Maloney and Hartmann, 2000) on the modulation of hurricane activity. Recent modeling studies have focused on the role of the MJO and Rossby waves (e.g., Ferreira and Schubert, 1996; Aivyer and Molinari, 2003) and/or the interaction of small-scale vortices (e.g., Holland 1995; Simpson et al. 1997; Hendrick et al. 2004), of which determinism could be also built by large-scale flows. The aforementioned studies suggest a unified view on hurricane formation, consisting of multiscale processes such as scale transition (e.g., from the MJO to Equatorial Rossby Waves and from waves to vortices), and scale interactions among vortices, convection, and surface heat and moisture fluxes. To depict the processes in the unified view, a high-resolution global model is needed. During the past several years, supercomputers have enabled the deployment of ultra-high resolution global models, obtaining remarkable forecasts of hurricane track and intensity (Atlas et al. 2005; Shen et al. 2006). In this work, hurricane genesis is investigated with the aid of a global mesoscale model on the NASA Columbia supercomputer by conducting numerical experiments on the genesis of six consecutive tropical cyclones (TCs) in May 2002. These TCs include two pairs of twin TCs in the Indian Ocean, Supertyphoon Hagibis in the West Pacific Ocean and Hurricane Alma in the East Pacific Ocean. It is found that the model is capable of predicting the genesis of five of these TCs about two to three days in advance. Our

  4. Survivors, not invaders, control forest development following simulated hurricane.

    Science.gov (United States)

    Plotkin, Audrey Barker; Foster, David; Carlson, Joel; Magill, Alison

    2013-02-01

    Wind disturbance profoundly shapes temperate forests but few studies have evaluated patterns and mechanisms of long-term forest dynamics following major windthrows. In 1990, we initiated a large hurricane simulation experiment in a 0.8-ha manipulation (pulldown) and 0.6-ha control area of a maturing Quercus rubra--Acer rubrum forest in New England. We toppled 276 trees in the pulldown, using a winch and cable, in the northwesterly direction of natural treefall from major hurricanes. Eighty percent of canopy trees and two-thirds of all trees > or = 5 cm dbh (diameter at breast height) suffered direct and indirect damage. We used 20 years of measurements to evaluate the trajectory and mechanisms of forest response after intense disturbance. Based on the patch size and disturbance magnitude, we expected pioneer tree and understory species to drive succession. The first decade of analyses emphasized tree seedling establishment and sprouting by damaged trees as the dominant mechanisms of forest recovery in this extensive damaged area. However, despite 80% canopy damage and 8000-m2 patch size, surviving overstory and advance regeneration controlled longer-term forest development. Residual oaks make up 42% of stand basal area after 20 years. The new cohort of trees, dominated by black birch advance regeneration, contributes 30% of stand basal area. There were shifts in understory vegetation composition and cover, but few species were gained or lost after 20 years. Stand productivity rebounded quickly (litterfall recovered to pre-disturbance levels in six years), but we predict that basal area in the pulldown will lag behind the control (which gained 6 m2/ha over 20 years) for decades to come. This controlled experiment showed that although the scale and intensity of damage were great, abundant advance regeneration, understory vegetation, and damaged trees remained, allowing the forest to resist changes in ecosystem processes and invasion by new species.

  5. Foreign Body Retrieval

    Medline Plus

    Full Text Available ... limitations of foreign body detection and removal? What is Foreign Body Retrieval? Foreign body retrieval involves the ... or computed tomography (CT). top of page How is the procedure performed? There are a number of ...

  6. Foreign Body Retrieval

    Medline Plus

    Full Text Available ... Us News Physician Resources Professions Site Index A-Z Foreign Body Retrieval Foreign body retrieval is the ... may undergo an ultrasound, x-ray or CT scan to locate and remove the object. Tell your ...

  7. Worldwide historical hurricane tracks from 1848 through the previous hurricane season

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Historical Hurricane Tracks web site provides visualizations of storm tracks derived from the 6-hourly (0000, 0600, 1200, 1800 UTC) center locations and...

  8. Generation of intermediately-long sea waves by weakly sheared winds

    CERN Document Server

    Chernyavski, V M; Golbraikh, E; Mond, M

    2010-01-01

    The present work concerns the numeric modeling of the sea-wave instability under the effect of the logarithmic wind at hurricane conditions (ignoring non-linear effects, such as wave breaking, foam production, etc. Powell et al. (2003)^1, Shtemler et al. (2003)^2. The central point of the study is the calculation of the growth rate, which is proportional to the fractional input energy from the wind to the wave exponentially varied with time. The present modeling demonstrates that the Miles-type model applying Charnock's formula Charnock (1955)^3 for roughness to the hurricane -wind parameters underestimates the growth rate of the wind waves 5-40 times as compared with the model employing the roughness and friction velocity adopted from experimental data for hurricane winds.^1 This occurs due to Charnock's formula fails at large wind speeds. The stability characteristics obtained on the base of the hurricane-wind experimental parameters are self-consistent with the other results of the observations. A maximum ...

  9. Connectionist Interaction Information Retrieval.

    Science.gov (United States)

    Dominich, Sandor

    2003-01-01

    Discussion of connectionist views for adaptive clustering in information retrieval focuses on a connectionist clustering technique and activation spreading-based information retrieval model using the interaction information retrieval method. Presents theoretical as well as simulation results as regards computational complexity and includes…

  10. Effects of Hurricane Katrina on the forest structure of taxodium distichum swamps of the Gulf Coast, USA

    Science.gov (United States)

    Middleton, B.A.

    2009-01-01

    Hurricane Katrina pushed mixed Taxodium distichum forests toward a dominance of Taxodium distichum (baldcypress) and Nyssa aquatica (water tupelo) because these species had lower levels of susceptibility to wind damage than other woody species. This study documents the volume of dead versus live material of woody trees and shrubs of T. distichum swamps following Hurricane Katrina along the Gulf Coast of Mississippi and Louisiana. Pearl River Wildlife Management Area near Canton, Mississippi had the highest winds of the study areas, and these forests were located in the northeast quadrant of Hurricane Katrina (sustained wind 151 kph (94 mph)). Jean Lafitte National Historical Park and Preserve south of New Orleans had medium to high winds (sustained winds 111 kph (69 mph) at the New Orleans lakefront). Cat Island National Wildlife Refuge had a lower level of winds and was positioned on the western edge of the storm. The forests at Pearl River and to a lesser extent at Jean Lafitte had the highest amount of structural damage in the study. For Cat Island, Jean Lafitte, and Pearl River, the total volume of dead material (debris) was 50, 80, and 370 m3 ha-1, respectively. The ratio of dead to live volume was 0.010, 0.082, and 0.039, respectively. For both of the dominant species, T. distichum and N. aquatica, the percentage of dead to live volume was less than 1. Subdominant species including Acer rubrum, Liquidambar styraciflua, Quercus lyrata, and Quercus nigra were more damaged by the storm at both Pearl River and Jean Lafitte. Only branches were damaged by Hurricane Katrina at Cat Island. Shrubs such as Morella cerifera, Euonymous sp., and Vaccinium sp. were often killed by the storm, while other species such as Cephalanthus occidentalis, Forestiera acuminata, and Cornus florida were not killed. Despite the fact that Hurricane Katrina was a Category 3 storm and struck Pearl River and Jean Lafitte fairly directly, dominant species of the T. distichum swamps were

  11. Air-Sea Spray Airborne Radar Profiler Characterizes Energy Fluxes in Hurricanes

    Science.gov (United States)

    Durden, Stephen L.; Esteban-Fermandez, D.

    2010-01-01

    A report discusses ASAP (Air-sea Spray Airborne Profiler), a dual-wavelength radar profiler that provides measurement information about the droplet size distribution (DSD) of sea-spray, which can be used to estimate heat and moisture fluxes for hurricane research. Researchers have recently determined that sea spray can have a large effect on the magnitude and distribution of the air-sea energy flux at hurricane -force wind speeds. To obtain information about the DSD, two parameters of the DSD are required; for example, overall DSD amplitude and DSD mean diameter. This requires two measurements. Two frequencies are used, with a large enough separation that the differential frequency provides size information. One frequency is 94 GHz; the other is 220 GHz. These correspond to the Rayleigh and Mie regions. Above a surface wind speed of 10 m/ s, production of sea spray grows exponentially. Both the number of large droplets and the altitude they reach are a function of the surface wind speed.

  12. Hurricane names: A bunch of hot air?

    Directory of Open Access Journals (Sweden)

    Gary Smith

    2016-06-01

    Full Text Available It has been argued that female-named hurricanes are deadlier because people do not take them seriously. However, this conclusion is based on a questionable statistical analysis of a narrowly defined data set. The reported relationship is not robust in that it is not confirmed by a straightforward analysis of more inclusive data or different data.

  13. Economic impacts of hurricanes on forest owners

    Science.gov (United States)

    Jeffrey P. Prestemon; Thomas P. Holmes

    2010-01-01

    We present a conceptual model of the economic impacts of hurricanes on timber producers and consumers, offer a framework indicating how welfare impacts can be estimated using econometric estimates of timber price dynamics, and illustrate the advantages of using a welfare theoretic model, which includes (1) welfare estimates that are consistent with neo-classical...

  14. Investigation of long-term hurricane activity

    NARCIS (Netherlands)

    Nguyen, B.M.; Van Gelder, P.H.A.J.M.

    2012-01-01

    This paper presents a new approach of applying numerical methods to model storm processes. A storm empirical track technique is utilized to simulate the full tracks of hurricanes, starting with their initial points over the sea and ending with their landfall locations or final dissipations. The

  15. Hurricane Ike versus an Atomic Bomb

    Science.gov (United States)

    Pearson, Earl F.

    2013-01-01

    The destructive potential of one of nature's most destructive forces, the hurricane, is compared to one of human's most destructive devices, an atomic bomb. Both can create near absolute devastation at "ground zero". However, how do they really compare in terms of destructive energy? This discussion compares the energy, the…

  16. The economics and ethics of Hurricane Katrina.

    Science.gov (United States)

    Rockwell, Llewellyn H; Block, Walter E

    2010-01-01

    How might free enterprise have dealt with Hurricane Katrina and her aftermath. This article probes this question at increasing levels of radicalization, starting with the privatization of several government “services” and ending with the privatization of all of them.

  17. Gulf Coast Hurricanes Situation Report #40

    Energy Technology Data Exchange (ETDEWEB)

    None

    2005-11-14

    On 11/12 Florida Power & Light (FPL) announced that crews had essentially completed Hurricane Wilma restoration efforts to all 3.2 million customers in South Florida who had been without power. Electricity restoration efforts are now essentially complete in Florida.

  18. Hurricanes as Heat Engines: Two Undergraduate Problems

    Science.gov (United States)

    Pyykko, Pekka

    2007-01-01

    Hurricanes can be regarded as Carnot heat engines. One reason that they can be so violent is that thermodynamically, they demonstrate large efficiency, [epsilon] = (T[subscript h] - T[subscript c]) / T[subscript h], which is of the order of 0.3. Evaporation of water vapor from the ocean and its subsequent condensation is the main heat transfer…

  19. Evacuating the Area of a Hurricane

    Centers for Disease Control (CDC) Podcasts

    2006-08-10

    If a hurricane warning is issued for your area, or authorities tell you to evacuate, take only essential items. If you have time, turn off gas, electricity, and water and disconnect appliances.  Created: 8/10/2006 by Emergency Communications System.   Date Released: 10/10/2007.

  20. Investigation of long-term hurricane activity

    NARCIS (Netherlands)

    Nguyen, B.M.; Van Gelder, P.H.A.J.M.

    2012-01-01

    This paper presents a new approach of applying numerical methods to model storm processes. A storm empirical track technique is utilized to simulate the full tracks of hurricanes, starting with their initial points over the sea and ending with their landfall locations or final dissipations. The theo

  1. Preparing for a Hurricane: Prescription Medications

    Centers for Disease Control (CDC) Podcasts

    2006-08-10

    What you should do to protect yourself and your family from a hurricane. As you evacuate, remember to take your prescription medicines with you.  Created: 8/10/2006 by Emergency Communications System.   Date Released: 7/17/2008.

  2. Hurricane Ike versus an Atomic Bomb

    Science.gov (United States)

    Pearson, Earl F.

    2013-01-01

    The destructive potential of one of nature's most destructive forces, the hurricane, is compared to one of human's most destructive devices, an atomic bomb. Both can create near absolute devastation at "ground zero". However, how do they really compare in terms of destructive energy? This discussion compares the energy, the…

  3. Atlantic Hurricane Activity: 1851-1900

    Science.gov (United States)

    Landsea, C. W.

    2001-12-01

    This presentation reports on the second year's work of a three year project to re-analyze the North Atlantic hurricane database (or HURDAT). The original database of six-hourly positions and intensities were put together in the 1960s in support of the Apollo space program to help provide statistical track forecast guidance. In the intervening years, this database - which is now freely and easily accessible on the Internet from the National Hurricane Center's (NHC's) Webpage - has been utilized for a wide variety of uses: climatic change studies, seasonal forecasting, risk assessment for county emergency managers, analysis of potential losses for insurance and business interests, intensity forecasting techniques and verification of official and various model predictions of track and intensity. Unfortunately, HURDAT was not designed with all of these uses in mind when it was first put together and not all of them may be appropriate given its original motivation. One problem with HURDAT is that there are numerous systematic as sell as some random errors in the database which need correction. Additionally, analysis techniques have changed over the years at NHC as our understanding of tropical cyclones has developed, leading to biases in the historical database that have not been addressed. Another difficulty in applying the hurricane database to studies concerned with landfalling events is the lack exact location, time and intensity at hurricane landfall. Finally, recent efforts into uncovering undocumented historical hurricanes in the late 1800s and early 1900s led by Jose Fernandez-Partagas have greatly increased our knowledge of these past events, which are not yet incorporated into the HURDAT database. Because of all of these issues, a re-analysis of the Atlantic hurricane database is being attempted that will be completed in three years. As part of the re-analyses, three files will be made available: {* } The revised Atlantic HURDAT (with six hourly intensities

  4. Wind Power

    OpenAIRE

    Makhalas, Kharsan Al; Alsehlli, Faisal

    2015-01-01

    This Bachelor thesis has been written at the Blekinge Institute of Technology. This thesis concentrates on the wind power and their components, also the large wind farm is studied. The electrical power is generated by using the power in wind to drive a wind turbine to produce mechanical power. This mechanical power can be converted into electrical power by using electrical induction generators. There are two types of the wind turbines, the horizontal axis and vertical axis wind turbine, where...

  5. Wind Sensor

    OpenAIRE

    Li, Jiaoyang; Ni, Jiqin

    2014-01-01

    Wind measurement is needed in many practical and scientific research situations. Some specific applications require to precisely measuring both wind direction and wind speed at the same time. Current commercial sensors for wind direction and wind speed measurement usually use ultrasonic technology and the sensors are very expensive (> $1500). In addition, the sensors are large in dimension and cannot measure airflow patterns in high spatial resolution. Therefore new and low cost wind speed an...

  6. Using Satellite SAR to Characterize the Wind Flow around Offshore Wind Farms

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Vincent, Pauline; Badger, Jake

    2015-01-01

    Offshore wind farm cluster effects between neighboring wind farms increase rapidly with the large-scale deployment of offshore wind turbines. The wind farm wakes observed from Synthetic Aperture Radar (SAR) are sometimes visible and atmospheric and wake models are here shown to convincingly...... to interpret due to mainly three issues: the limited number of samples per wind directional sector, the coastal wind speed gradient, and oceanic bathymetry effects in the SAR retrievals. A new methodology is developed and presented. This method overcomes effectively the first issue and in most cases...

  7. Forecasting Evaluation of WindSat in the Coastal Environment

    Science.gov (United States)

    Lee, Thomas F.; Bettenhausen, Mike H.; Hawkins, Jeffrey D.; Richardson, Kim; Jedlovec, Gary; Smith, Matt

    2012-01-01

    WindSat has demonstrated that measurements from polarimetric space-based microwave radiometers can be used to retrieve global ocean surface vector winds. Since the date of launch in 2003, substantial incremental improvements have been made to WindSat data processing, calibration, and retrieval algorithms. The retrievals now have higher resolution, improved wind vector ambiguity removal, and enhanced capability to represent high winds. Utilization of WindSat retrievals (wind vectors, total precipitable water, rainrate and sea surface temperature) will be demonstrated in the context of operational weather forecasting applications, especially the monitoring of topographically-forced winds. Examples will be presented from various parts of the world, including inland seas, midlatitude oceans, the tropics, and the United States. We will illustrate retrievals in extreme high- and extreme low-wind regimes, both of which can be problematic. Rain contamination will be addressed. We will include a comparison of WindSat vector maps to corresponding maps from the QuikScat scatterometer. We will discuss how near-realtime data from WindSat is being transitioned to specific offices within the National Weather Service.

  8. Learning from traffic data collected before, during and after a hurricane

    Directory of Open Access Journals (Sweden)

    Erik Archibald

    2012-07-01

    Full Text Available Hurricanes harm people and damage property through extreme wind speeds and flooding associated with heavy rains and storm surge. One of the most effective and widely used tactics to protect people from hurricanes is evacuation. Improved knowledge of the behavior of communities before, during and after an evacuation can better support emergency planning and operations, and thus help make evacuations safer and more efficient. The objective of this work is to identify ways to use traffic data to better understand evacuation behavior and to explore ways to integrate traffic data into evacuation planning and response. Traffic data collected in Delaware before, during and after Hurricane Irene in August 2011 using automated traffic recorders are assembled and analyzed. The analysis shows that a significant number of residents and visitors evacuated from the beach communities and the evacuation patterns are very similar to the traffic patterns experienced on summer weekends. These insights suggest that this type of analysis may also be of value for other events in other communities.

  9. Impact of a major hurricane on surgical services in a university hospital.

    Science.gov (United States)

    Norcross, E D; Elliott, B M; Adams, D B; Crawford, F A

    1993-01-01

    Hurricane Hugo struck Charleston, South Carolina, on September 21, 1989. This report analyzes the impact this storm had upon surgical care at a university medical center. Although disaster planning began on September 17, hurricane damage by high winds and an 8.7-foot tidal surge led to loss of emergency power and water. Consequently, system failures occurred in air conditioning, vacuum suction, steam and ethylene oxide sterilization, plumbing, central paging, lighting, and refrigeration. The following surgical support services were affected. In the blood bank, lack of refrigeration meant no platelet packs for 2 days. In radiology, loss of electrical power damaged CT/MRI scanners and flooding ruined patient files, resulting in lost information. In the intensive care unit, loss of electricity meant no monitors and hand ventilation was used for 4 hours. In the operating room, lack of temperature and humidity control (steam, water, and suction supply) halted elective surgery until October 2. Ground and air transportation were limited by unsafe landing sites, impassable roads, and personnel exhaustion. Surgical planning for a major hurricane should include: 1) a fail-safe source of electrical power, 2) evacuation of as many critically ill patients as possible before the storm, 3) cancellation of all elective surgery, and 4) augmented ancillary service staffing with some, although limited, physician support.

  10. What controls early or late onset of tropical North Atlantic hurricane season?

    Science.gov (United States)

    Zuo, Heng; Li, Tim; Liu, Jia; Peng, Melinda

    2016-06-01

    The occurrence of first hurricane in early summer signifies the onset of an active Atlantic hurricane season. The interannual variation of this hurricane onset date is examined for the period 1979-2013. It is found that the onset date has a marked interannual variation. The standard deviation of the interannual variation of the onset day is 17.5 days, with the climatological mean onset happening on July 23. A diagnosis of tropical cyclone (TC) genesis potential index (GPI) indicates that the major difference between an early and a late onset group lies in the maximum potential intensity (MPI). A further diagnosis of the MPI shows that it is primarily controlled by the local SST anomaly (SSTA). Besides the SSTA, vertical shear and mid-tropospheric relative humidity anomalies also contribute significantly to the GPI difference between the early and late onset groups. It is found that the anomalous warm (cold) SST over the tropical Atlantic, while uncorrelated with the Niño3 index, persists from the preceding winter to concurrent summer in the early (late) onset group. The net surface heat flux anomaly always tends to damp the SSTA, which suggests that ocean dynamics may play a role in maintaining the SSTA in the tropical Atlantic. The SSTA pattern with a maximum center in northeastern tropical Atlantic appears responsible for generating the observed wind and moisture anomalies over the main TC development region. A further study is needed to understand the initiation mechanism of the SSTA in the Atlantic.

  11. Near-inertial motions in the DeSoto Canyon during Hurricane Georges

    Science.gov (United States)

    Jordi, Antoni; Wang, Dong-Ping; Hamilton, Peter

    2016-09-01

    Hurricane Georges passed directly over an array of 13 moorings deployed in the DeSoto Canyon in the northern Gulf of Mexico on 27-28 September 1998. Current velocity data from the mooring array were analyzed together with a primitive-equation model simulation with realistic hurricane forcing, to characterize the generation and propagation of the hurricane-generated near-inertial waves. The model successfully reproduces the observed mean (sub-inertial) and near-inertial motions. The upper ocean response is strongly impacted by the canyon 'wall': a strong jet is formed along the slope, and the near-inertial motions on the shelf are rapidly suppressed. The model results moreover suggest that strong near-inertial waves in the mixed layer are mostly trapped in an energy flux recirculating gyre around the canyon. This gyre retains the near-inertial energy in the canyon region and enhances the transfer of near-inertial energy below the mixed layer. Additional simulations with idealized topographies show that the presence of a steep slope rather than the canyon is fundamental for the generation of this recirculating gyre. The near-inertial wave energy budget shows that during the study period the wind generated an input of 6.79 × 10-2 Wm-2 of which about 1/3, or 2.43 × 10-2 Wm-2, was transferred below the mixed layer. The horizontal energy flux into and out of the canyon region, in contrast, was relatively weak.

  12. Bringing satellite winds to hub-height

    DEFF Research Database (Denmark)

    Badger, Merete; Pena Diaz, Alfredo; Bredesen, Rolv Erlend

    2012-01-01

    Satellite observations of the ocean surface can provide detailed information about the spatial wind variability over large areas. This is very valuable for the mapping of wind resources offshore where other measurements are costly and sparse. Satellite sensors operating at microwave frequencies...... measure the amount of radar backscatter from the sea surface, which is a function of the instant wind speed, wind direction, and satellite viewing geometry. A major limitation related to wind retrievals from satellite observations is that existing empirical model functions relate the radar backscatter...

  13. Impact of Hurricane Exposure on Reproductive Health Outcomes, Florida, 2004.

    Science.gov (United States)

    Grabich, Shannon C; Robinson, Whitney R; Konrad, Charles E; Horney, Jennifer A

    2017-08-01

    Prenatal hurricane exposure may be an increasingly important contributor to poor reproductive health outcomes. In the current literature, mixed associations have been suggested between hurricane exposure and reproductive health outcomes. This may be due, in part, to residual confounding. We assessed the association between hurricane exposure and reproductive health outcomes by using a difference-in-difference analysis technique to control for confounding in a cohort of Florida pregnancies. We implemented a difference-in-difference analysis to evaluate hurricane weather and reproductive health outcomes including low birth weight, fetal death, and birth rate. The study population for analysis included all Florida pregnancies conceived before or during the 2003 and 2004 hurricane season. Reproductive health data were extracted from vital statistics records from the Florida Department of Health. In 2004, 4 hurricanes (Charley, Frances, Ivan, and Jeanne) made landfall in rapid succession; whereas in 2003, no hurricanes made landfall in Florida. Overall models using the difference-in-difference analysis showed no association between exposure to hurricane weather and reproductive health. The inconsistency of the literature on hurricane exposure and reproductive health may be in part due to biases inherent in pre-post or regression-based county-level comparisons. We found no associations between hurricane exposure and reproductive health. (Disaster Med Public Health Preparedness. 2017;11:407-411).

  14. [Hurricane Paloma's effects on seagrasses along Jardines de la Reina Archipelago, Cuba].

    Science.gov (United States)

    Guimarais, Mayrene; Zúñiga, Adán; Pina, Fabián; Matos, Felipe

    2013-09-01

    Seagrasses are one of the most important coastal ecosystems since they promote organic matter flow, nutrient cycling, food availability and refuge. Until now, reports on damages caused by storms and hurricanes on seagrass beds are uncommon and highly variable. The seagrass meadows of the East end of Jardines de la Reina archipelago were surveyed from Nov. 29th to Dec. 5th of 2008, in order to determinate the effects from the passing of Hurricane Paloma: a category three storm on the Saffir-Simpsom scale. A rapid field assessment of the affected areas was carried out using the manta tow technique. In six sites, seagrass was quantitatively evaluated using a 15cm diameter core (four sampling units per site) and shoot density was calculated. Remote sensing techniques were used to estimate seagrass cover. To estimate the percentage of affected areas, a Region of Interest (ROI) was first created over a Landsat image. The percentage of seagrass affected within the ROI was estimated through direct georeferentiation of the contours of the damaged area and with a comparison to the total seagrass extension. To find possible explanations for damages, a false colour image was created using the near infrared band, to highlight the differences between emerged and submerged zones. The direction of winds was estimated using ArcGis 9.2 creating circular buffers, from the centre of the hurricane and generating lines tangent to the buffers. Seagrass in the region was dominated by the angiosperm Thalassia testudinum. Regional mean density was 1 321 +/- 721 shoots/m2, a value regarded as high for the Caribbean area. Seagrass meadows were partly affected by sediment accumulation on the shoots of T. testudinum and uprooting rhizomes. The 7.6 km2 disturbed area represented 1% of the total seagrass area. Other sites, closer to the centre of the hurricane, did not show any damages on the marine vegetation. The keys location with respect to the hurricane track was the most likely cause of the

  15. Seismic and pressure signals when a hurricane moves over an array

    Science.gov (United States)

    Tanimoto, Toshiro

    2017-04-01

    General structure in a tropical cyclone (hurricane/typhoon) in the atmosphere is reasonably well known; it has a very calm central region surrounded by a circular eyewall at a radius of about 50-100 km from the center. Winds are strongest at the eyewall and outside the eyewall, there exists a fairly strong windy region that extends to about 500-1000 km from the center. The main purpose of this study is to understand how seismic waves in the solid Earth are generated by a tropical cyclone. We focus on a low frequency band (below 0.05 Hz) in this study. The basic mechanism of seismic wave excitation in such a low frequency band is relatively straightforward; changes in wind speed generate surface pressure changes and that in turn excite ground motions in the solid Earth. In a rare example of a hurricane (Hurricane Isaac in 2012) that moved through the USARRAY (Earthscope), that had co-located seismometers and barometers, we can directly examine how ground motions and surface pressure are influenced by the passage of a hurricane eye. When a hurricane eye passes over a station, pressure and three-component seismic time series show a gap in amplitude (envelope) for filtered time series below 0.05 Hz. Typically, long envelopes in time series appear to be truncated by a gap that is at the arrival time of the hurricane eye (although it is not a real gap in data). Using a few stations on the track of a hurricane, we can show that this gap moves in time. This feature only occurs for stations that are within about 50 km from the hurricane track. We also point out that pressure and vertical ground motions show very high correlation (the correlation coefficient or CC about 0.8-0.9). On the other hand, horizontal-component seismic data show small correlation with pressure (CC close to zero) even though their amplitudes (envelopes) show gaps that are coincident in time with pressure. What it means is that phase is quite incoherent between pressure and horizontal components

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

    Science.gov (United States)

    Gesch, Dean B.

    2009-01-01

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

  17. Wind energy applications of synthetic aperture radar

    Energy Technology Data Exchange (ETDEWEB)

    Bruun Christiansen, M.

    2006-11-15

    Synthetic aperture radars (SAR), mounted on satellites or aircraft, have proven useful for ocean wind mapping. Wind speeds at the height 10 m may be retrieved from measurements of radar backscatter using empirical model functions. The resulting wind fields are valuable in offshore wind energy planning as a supplement to on site measurements, which are costly and sparse, and model wind fields, which are not fully validated. Two applications of SAR measurements in offshore wind energy planning are addressed here: the study of wind farm wake effects and the potential of using SAR winds in offshore wind resource assessment. Firstly, wind wakes behind two large offshore wind farms in Denmark Horns Rev and Nysted are identified. A region of reduced wind speed is found downstream of both wind farms from the SAR wind fields. The wake extent and magnitude depends on the wind speed, the atmospheric stability, and the fraction of turbines operating. Wind farm wake effects are detected up to 20 km downwind of the last turbine. This distance is longer than predicted by state-of-the art wake models. Wake losses are typically 10-20% near the wind farms. Secondly, the potential of using SAR wind maps in offshore wind resource assessment is investigated. The resource assessment is made through Weibull fitting to frequency observations of wind speed and requires at least 100 satellite observations per year for a given site of interest. Predictions of the energy density are very sensitive to the wind speed and the highest possible accuracy on SAR wind retrievals is therefore sought. A 1.1 m s{sup -1} deviation on the mean wind speed is found through comparison with mast measurements at Horns Rev. The accuracy on mean wind speeds and energy densities found from satellite measurements varies with different empirical model functions. Additional uncertainties are introduced by the infrequent satellite sampling at fixed times of the day. The accuracy on satellite based wind resource

  18. "Keeping it Real -High School Science Curriculum"- Hurricane Katrina and BP Oil Spill inspire creative curriculum by Dave Jungblut, Oakcrest High School Science Teacher, Mays Landing, NJ

    Science.gov (United States)

    Jungblut, D.

    2011-12-01

    After Hurricane Katrina devastated Gulf Coast homes in 2005, Oakcrest High School science teacher and geologist, Dave Jungblut, traveled from Gulfport to Ocean Springs, Mississippi and conducted research to determine whether property damage was caused by wind or water. Jungblut wrote several studies, " Katrina Straight- Line Wind Field Study", "Applying Research to Practical Use for Hurricane Katrina Homeowners", and "Hurricane Katrina Wind Study" proving wind damage. Jungblut's research, done pro bono, helped thousands of homeowner's in the Mississippi area be reimbursed by insurance companies for wind damage caused by Hurricane Katrina http://www.hurricanekatrinastudy.com/ Jungblut incorporated his extensive data, in a high school curriculum that is now part of the science program he teaches each year. In January 2010, Jungblut presented "Hurricane Forensics" curriculum at the Rutgers Center for Mathematics, Science and Computer January 2009 Workshop http://www.dimacs.rutgers.edu/wst/. Through labs and creative hands-on activities, Jungblut challenged his students to analyze the photographic evidence, and data he collected, for themselves. Jungblut taught his students how to use geologic and forensic inquiry techniques to discover the difference between straight-line winds from microburst activity. The students applied the concept of the Geological Principle of Relative Dating, to determine the sequence of events that happened during Hurricane Katrina. They built model structures, which were subjected to wind and water forces to better understand the effects of these phenomena, Finally, the students evaluated local and worldwide environmental issues, such as land use risks and benefits, in the face of global warming, In the spring of 2010 when the BP Oil Spill occurred, Jungblut realized, another opportunity to bring real world issues into the classroom. After exploring scientific concepts relating to this environmental crisis, Jungblut challenged his students to

  19. Mapping potential carbon and timber losses from hurricanes using a decision tree and ecosystem services driver model.

    Science.gov (United States)

    Delphin, S; Escobedo, F J; Abd-Elrahman, A; Cropper, W

    2013-11-15

    Information on the effect of direct drivers such as hurricanes on ecosystem services is relevant to landowners and policy makers due to predicted effects from climate change. We identified forest damage risk zones due to hurricanes and estimated the potential loss of 2 key ecosystem services: aboveground carbon storage and timber volume. Using land cover, plot-level forest inventory data, the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, and a decision tree-based framework; we determined potential damage to subtropical forests from hurricanes in the Lower Suwannee River (LS) and Pensacola Bay (PB) watersheds in Florida, US. We used biophysical factors identified in previous studies as being influential in forest damage in our decision tree and hurricane wind risk maps. Results show that 31% and 0.5% of the total aboveground carbon storage in the LS and PB, respectively was located in high forest damage risk (HR) zones. Overall 15% and 0.7% of the total timber net volume in the LS and PB, respectively, was in HR zones. This model can also be used for identifying timber salvage areas, developing ecosystem service provision and management scenarios, and assessing the effect of other drivers on ecosystem services and goods. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Generation of intermediately-long sea waves by weakly sheared winds

    CERN Document Server

    Chernyavski, V M; Golbraikh, E; Mond, M

    2010-01-01

    The present work concerns the numeric modeling of the sea-wave instability under the effect of the logarithmic-wind profile at hurricane conditions. Non-linear effects, such as wave breaking, foam production, etc. Powell et al. (2003), Shtemler et al. (2010) are ignored. The central point of the study is the calculation of the wave growth rate, which is proportional to the fractional input energy from the wind to the wave exponentially varied with time. The present modeling demonstrates that the Miles-type model applying Charnock's formula for roughness to the hurricane-wind parameters underestimates the growth rate from 5 to 40 times as compared with the model employing the roughness and friction velocity adopted from experimental data for hurricane winds.1 This occurs due to Charnock's formula fails at large wind speeds. The stability characteristics found on the base of the hurricane-wind experimental parameters are consistent with the other results of the observations. Obtained in the present study a maxi...

  1. Quality assessment of weather radar wind profiles during bird migration

    NARCIS (Netherlands)

    Holleman, I.; van Gasteren, H.; Bouten, W.

    2008-01-01

    Wind profiles from an operational C-band Doppler radar have been combined with data from a bird tracking radar to assess the wind profile quality during bird migration. The weather radar wind profiles (WRWPs) are retrieved using the well-known volume velocity processing (VVP) technique. The X-band

  2. 78 FR 32296 - Second Allocation of Public Transportation Emergency Relief Funds in Response to Hurricane Sandy...

    Science.gov (United States)

    2013-05-29

    ... Response to Hurricane Sandy: Response, Recovery & Resiliency AGENCY: Federal Transit Administration (FTA... recipients most severely affected by Hurricane Sandy: the Metropolitan Transportation Authority, New Jersey... Federal Register notice, bringing the total amount of Hurricane Sandy Emergency Relief funds allocated...

  3. Private information retrieval

    CERN Document Server

    Yi, Xun; Bertino, Elisa

    2013-01-01

    This book deals with Private Information Retrieval (PIR), a technique allowing a user to retrieve an element from a server in possession of a database without revealing to the server which element is retrieved. PIR has been widely applied to protect the privacy of the user in querying a service provider on the Internet. For example, by PIR, one can query a location-based service provider about the nearest car park without revealing his location to the server.The first PIR approach was introduced by Chor, Goldreich, Kushilevitz and Sudan in 1995 in a multi-server setting, where the user retriev

  4. The basic mechanism behind the hurricane-free warm tropical ocean

    Directory of Open Access Journals (Sweden)

    Z. Yuan

    2010-01-01

    Full Text Available No hurricane is detected in the tropics off the Brazilian coast due to the lack of initial conditions (e.g., the weak vertical shear of horizontal wind despite that high sea surface temperature is available. According to previous studies, the initial conditions (as the ingredients of hurricane's embryo are related so that the thick warm-and-moist layer (due to the updraft vapour below a cold-and-dry layer frames the convective instability which enhances diabatic processes accompanied by tropical cyclones with the weak vertical shear. So the basic question is how, starting with an internal-disturbance-free balance-situation, external forces create the rapidly-upward acceleration of moist air at the warm sea surface. The answer is revealed by the vertical-momentum equation which shows that boosted by the external-force-induced significant lower-layer equatorial westerly wind (LLEWW, the upward (unit-mass acceleration could be as significant as the midlatitude Coriolis force. Besides creating cyclonic vortices through the upward acceleration and diabatic processes, the external-force-induced significant-LLEWW could directly create cyclonic wind shears along with easterly jets for the low-level cyclonic vorticity through reducing the peak value of zonally-homogeneous trade easterlies (centered at the Equator between the Northern and Southern Hemisphere subtropical high-belts. We emphasize external forces to avoid the ''chicken-and-egg'' problem accompanying nonlinear interactions of internal-forcing processes. The external-force-induced significant-LLEWW could result from the deflection of the cross-equatorial flow characterized by the seasonal shift coincident with that of locations of most embryos. This significant cross-equatorial flow is driven by the significant differential heating between the largest continent with the highest plateau and the largest ocean with the warm pool located to the east and on the equatorward side of the continent on

  5. Rediscovering community--reflections after Hurricane Sandy.

    Science.gov (United States)

    See, Sharon

    2013-01-01

    Hoboken, New Jersey, is a town of 50,000 residents located across the Hudson River from New York City. Most of Hoboken's infrastructure was compromised during Hurricane Sandy as a result of flooding and power outages that rendered many businesses inoperable, including all of the pharmacies in town. Despite a focus on emergency preparedness since Hurricane Katrina and 9/11, there were no contingencies in place to facilitate and assess the medication needs of the community in the event of a natural disaster. This essay describes how the author rediscovered the meaning of community, and through working with colleagues in other health care disciplines and non-health care volunteers, provided care to patients in suboptimal circumstances.

  6. Hurricane damaged fixed platforms and wellhead structures

    Energy Technology Data Exchange (ETDEWEB)

    Shuttleworth, E.P.; Frieze, P.A.

    1998-03-01

    The objective of this study was to review data on damages to offshore platforms with a view to determining their suitability for further exploitation and analysis through a preliminary assessment of trends in the data when viewed from a risk standpoint. To realise this objective, a database on hurricane and other storm related damages was generated and past design practice, particularly concerning environmental load levels, was established. Information was gathered on extreme wave heights, damages, platform details, pushover analyses and structural frame load tests. The information was obtained through: a literature survey of journals, conference proceedings, design codes and guidelines; approaches to organisations in the offshore industry with significant experience of hurricanes, storm-damaged structures and pushover analyses; and interrogation of three major databases on offshore storm and other damages - PMB, MMS and WOAD. (author)

  7. Atlantic hurricane surge response to geoengineering

    Energy Technology Data Exchange (ETDEWEB)

    Moore, John C.; Grinsted, Aslak; Guo, Xiaoran; Yu, Xiaoyong; Jevrejeva, Svetlana; Rinke, Annette; Cui, Xuefeng; Kravitz, Ben; Lenton, Andrew; Watanabe, Shingo; Ji, Duoying

    2015-10-26

    Devastating Atlantic hurricanes are relatively rare events. However their intensity and frequency in a warming world may rapidly increase by a factor of 2-7 for each degree of increase in mean global temperature. Geoengineering by stratospheric sulphate aerosol injection cools the tropics relative to the polar regions, including the hurricane main development region in the Atlantic, suggesting that geoengineering may be an effective method of controlling hurricanes. We examine this hypothesis using 8 Earth System Model simulations of climate under the GeoMIP G3 and G4 schemes that use stratospheric aerosols to reduce the radiative forcing under the RCP4.5 scenario. Global mean temperature increases are greatly ameliorated by geoengineering, and tropical temperature increases are at most half of those in RCP4.5, but sulphate injection would have to double between 2020 and 2070 to balance RCP 4.5 to nearly 10 Tg SO2 yr-1, with consequent implications for damage to stratospheric ozone. We project changes in storm frequencies using a temperature-dependent Generalized Extreme Value statistical model calibrated by historical storm surges from 1923 and observed temperatures. The numbers of storm surge events as big as the one that caused the 2005 Katrina hurricane are reduced by about 50% compared with no geoengineering, but this is only marginally statistically significant. However, when sea level rise differences at 2070 between RCP4.5 and geoengineering are factored in to coastal flood risk, we find that expected flood levels are reduced by about 40 cm for 5 year events and perhaps halved for 50 year surges.

  8. Atlantic hurricane surge response to geoengineering.

    Science.gov (United States)

    Moore, John C; Grinsted, Aslak; Guo, Xiaoran; Yu, Xiaoyong; Jevrejeva, Svetlana; Rinke, Annette; Cui, Xuefeng; Kravitz, Ben; Lenton, Andrew; Watanabe, Shingo; Ji, Duoying

    2015-11-10

    Devastating floods due to Atlantic hurricanes are relatively rare events. However, the frequency of the most intense storms is likely to increase with rises in sea surface temperatures. Geoengineering by stratospheric sulfate aerosol injection cools the tropics relative to the polar regions, including the hurricane Main Development Region in the Atlantic, suggesting that geoengineering may mitigate hurricanes. We examine this hypothesis using eight earth system model simulations of climate under the Geoengineering Model Intercomparison Project (GeoMIP) G3 and G4 schemes that use stratospheric aerosols to reduce the radiative forcing under the Representative Concentration Pathway (RCP) 4.5 scenario. Global mean temperature increases are greatly ameliorated by geoengineering, and tropical temperature increases are at most half of those temperature increases in the RCP4.5. However, sulfate injection would have to double (to nearly 10 teragrams of SO2 per year) between 2020 and 2070 to balance the RCP4.5, approximately the equivalent of a 1991 Pinatubo eruption every 2 y, with consequent implications for stratospheric ozone. We project changes in storm frequencies using a temperature-dependent generalized extreme value statistical model calibrated by historical storm surges and observed temperatures since 1923. The number of storm surge events as big as the one caused by the 2005 Katrina hurricane are reduced by about 50% compared with no geoengineering, but this reduction is only marginally statistically significant. Nevertheless, when sea level rise differences in 2070 between the RCP4.5 and geoengineering are factored into coastal flood risk, we find that expected flood levels are reduced by about 40 cm for 5-y events and about halved for 50-y surges.

  9. Complicated grief associated with hurricane Katrina.

    Science.gov (United States)

    Shear, M Katherine; McLaughlin, Katie A; Ghesquiere, Angela; Gruber, Michael J; Sampson, Nancy A; Kessler, Ronald C

    2011-08-01

    Although losses are important consequences of disasters, few epidemiological studies of disasters have assessed complicated grief (CG) and none assessed CG associated with losses other than death of loved one. Data come from the baseline survey of the Hurricane Katrina Community Advisory Group, a representative sample of 3,088 residents of the areas directly affected by Hurricane Katrina. A brief screen for CG was included containing four items consistent with the proposed DSM-V criteria for a diagnosis of bereavement-related adjustment disorder. Fifty-eight and half percent of respondents reported a significant hurricane-related loss: Most-severe losses were 29.0% tangible, 9.5% interpersonal, 8.1% intangible, 4.2% work/financial, and 3.7% death of loved one. Twenty-six point one percent respondents with significant loss had possible CG and 7.0% moderate-to-severe CG. Death of loved one was associated with the highest conditional probability of moderate-to-severe CG (18.5%, compared to 1.1-10.5% conditional probabilities for other losses), but accounted for only 16.5% of moderate-to-severe CG due to its comparatively low prevalence. Most moderate-to-severe CG was due to tangible (52.9%) or interpersonal (24.0%) losses. Significant predictors of CG were mostly unique to either bereavement (racial-ethnic minority status, social support) or other losses (prehurricane history of psychopathology, social competence.). Nonbereavement losses accounted for the vast majority of hurricane-related possible CG despite risk of CG being much higher in response to bereavement than to other losses. This result argues for expansion of research on CG beyond bereavement and alerts clinicians to the need to address postdisaster grief associated with a wide range of losses. © 2011 Wiley-Liss, Inc.

  10. Drag coefficient for the air-sea exchange: foam impact in hurricane conditions

    CERN Document Server

    Golbraikh, Ephim

    2014-01-01

    A physical model is proposed for the estimation of the foam impact on the variation of the effective drag coefficient, C_d, with reference to the wind speed U10 in stormy and hurricane conditions. In the present model C_d is approximated by partitioning the sea surface into foam-covered and foam-free areas. Based on the available optical and radiometric measurements of the fractional foam coverage and the characteristic roughness of the sea-surface in the saturation limit of the foam coverage, the model yields the resulting dependence of C_d vs U10. This dependence is in fair agreement with that evaluated from field measurements of the vertical variation of the mean wind speed.

  11. Drag coefficient for the air-sea exchange in hurricane conditions

    CERN Document Server

    Golbraikh, E

    2013-01-01

    The physical model is proposed for prediction of the non-monotonic drag coefficient variation with the neutral stability 10-m wind speed, U10. The model is based upon measurements of the foam coverage fraction and characteristic size of foam bubbles with U10, and on the drag coefficient approximation by the linearly weighted averaging over alternating foam-free and foam-covered portions of the ocean surface. The obtained drag coefficient is in fair agreement with that obtained by field measurements of the vertical variation of mean wind speed in Powell et al. (Nature, 2003) which discover reduction of the sea-surface drag with U10 rising to hurricane conditions.

  12. Coastal Change During Hurricane Isabel 2003

    Science.gov (United States)

    Morgan, Karen

    2009-01-01

    On September 18, 2003, Hurricane Isabel made landfall on the northern Outer Banks of North Carolina. At the U.S. Army Corps of Engineer's Field Research Facility in Duck, 125 km north of where the eyewall cut across Hatteras Island, the Category 2 storm generated record conditions for the 27 years of monitoring. The storm produced an 8.1 m high wave measured at a waverider buoy in 20 m of water and a 1.5 m storm surge. As part of a program to document and better understand the changes in vulnerability of the Nation's coasts to extreme storms, the U.S. Geological Survey (USGS), in collaboration with the National Aeronautics and Space Administration (NASA), surveyed the impact zone of Hurricane Isabel. Methods included pre- and post-storm photography, videography, and lidar. Hurricane Isabel caused extensive erosion and overwash along the Outer Banks near Cape Hatteras, including the destruction of houses, the erosion of protective sand dunes, and the creation of island breaches. The storm eroded beaches and dunes in Frisco and Hatteras Village, southwest of the Cape. Overwash deposits covered roads and filled homes with sand. The most extensive beach changes were associated with the opening of a new breach about 500 m wide that divided into three separate channels that completely severed the island southwest of Cape Hatteras. The main breach, and a smaller one several kilometers to the south (not shown), occurred at minima in both island elevation and island width.

  13. Wind Structure and Wind Loading

    DEFF Research Database (Denmark)

    Brorsen, Michael

    The purpose of this note is to provide a short description of wind, i.e. of the flow in the atmosphere of the Earth and the loading caused by wind on structures. The description comprises: causes to the generation of windhe interaction between wind and the surface of the Earthhe stochastic nature...... of windhe interaction between wind and structures, where it is shown that wind loading depends strongly on this interaction...

  14. Hurricane Mitch: Landscape Analysis of Damaged Forest Resources of the Bay Islands and Caribbean Coast of Honduras

    Science.gov (United States)

    Doyle, Thomas W.; Michot, Thomas C.; Roetker, Fred; Sullivan, Jason; Melder, Marcus; Handley, Benjamin; Balmat, Jeff

    2002-01-01

    The advent of analog and digital video has provided amateur photographers with professional-like technology to capture dynamic images with ease and clarity. Videography is also rapidly changing traditional business and scientific applications. In the natural sciences, camcorders are being used largely to record timely observations of plant and animal behavior or consequence of some catastrophic event. Spectacular video of dynamic events such as hurricanes, volcanic eruptions and wildfire document the active process and aftermath. Scientists can analyze video images to quantify aspects of a given event, behavior, or response, temporally and spatially. In this study we demonstrate the simple use of an aerial application of videography to record the spatial extent and damage expression of mangrove forest in the Bay Islands and mainland coast of northern Honduras from wind damage following Hurricane Mitch (1998). In this study, we conducted a video overflight of coastal forests of the Bay Islands and mainland coast of northern Honduras 14 months after impact by Hurricane Mitch (1998). Coastal areas were identified where damage was evident and described relative to damage extent to forest cover, windfall orientation, and height of downed trees. The variability and spatial extent of impact on coastal forest resources is related to reconstructed wind profiles based on model simulations of Mitch's path, strength, and circulation during landfall.

  15. The Aquarius Salinity Retrieval Algorithm

    Science.gov (United States)

    Meissner, Thomas; Wentz, Frank; Hilburn, Kyle; Lagerloef, Gary; Le Vine, David

    2012-01-01

    The first part of this presentation gives an overview over the Aquarius salinity retrieval algorithm. The instrument calibration [2] converts Aquarius radiometer counts into antenna temperatures (TA). The salinity retrieval algorithm converts those TA into brightness temperatures (TB) at a flat ocean surface. As a first step, contributions arising from the intrusion of solar, lunar and galactic radiation are subtracted. The antenna pattern correction (APC) removes the effects of cross-polarization contamination and spillover. The Aquarius radiometer measures the 3rd Stokes parameter in addition to vertical (v) and horizontal (h) polarizations, which allows for an easy removal of ionospheric Faraday rotation. The atmospheric absorption at L-band is almost entirely due to molecular oxygen, which can be calculated based on auxiliary input fields from numerical weather prediction models and then successively removed from the TB. The final step in the TA to TB conversion is the correction for the roughness of the sea surface due to wind, which is addressed in more detail in section 3. The TB of the flat ocean surface can now be matched to a salinity value using a surface emission model that is based on a model for the dielectric constant of sea water [3], [4] and an auxiliary field for the sea surface temperature. In the current processing only v-pol TB are used for this last step.

  16. Nova Scotia Power response to Hurricane Juan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-10-01

    Hurricane Juan hit the Halifax Regional Municipality on September 28, 2003, creating the largest outage in Nova Scotia Power's history. This detailed report documents the extensive damage that Hurricane Juan caused to the power transmission and distribution system in Nova Scotia. It also reviews the massive power restoration effort, with reference to numerous interviews, computer records and data logs which offer a wide range of observations, statistics and insights into the preparation and performance of Nova Scotia Power Inc. (NSPI) and the efforts of other key organizations following the storm. NSPI organized a recovery effort that matched the intensity of the hurricane. A fire in the Scotia Square Office Tower caused the evacuation of the company's call centre. The Tufts Cove station in Dartmouth, which generates 400 megawatts of power, was forced to shut down. Excess electricity was moved into New Brunswick and other jurisdictions to maintain system stability. The main priority was to restore customers back to service. Within 5 days of the hurricane, 95 per cent of those who lost power had service restored. Hurricane Juan caused the most damage to the transmission and distribution system in NSPI's history. Three out of five high capacity transmission lines were put out of service. Three 120-foot high transmission towers fell, and 17 main transmission lines were damaged and put out of service. Forty-five major substations were affected and 145 distribution feeders were damaged or tripped off, including 106 in the Halifax Regional Municipality. Large portions of 4,500 kilometres of local distribution lines in the Halifax Regional Municipality were damaged, including thousands of kilometers across the Northeast. The power crew, consisting of 2,000 individuals from the region and neighbouring utilities in New Brunswick and Maine, worked for 15 consecutive days to replace 275 transformers, 760 power poles, and 125,000 metres of conductor wire. NSPI

  17. Documentation and hydrologic analysis of Hurricane Sandy in New Jersey, October 29–30, 2012

    Science.gov (United States)

    Suro, Thomas P.; Deetz, Anna; Hearn, Paul

    2016-11-17

    In 2012, a late season tropical depression developed into a tropical storm and later a hurricane. The hurricane, named “Hurricane Sandy,” gained strength to a Category 3 storm on October 25, 2012, and underwent several transitions on its approach to the mid-Atlantic region of the eastern coast of the United States. By October 28, 2012, Hurricane Sandy had strengthened into the largest hurricane ever recorded in the North Atlantic and was tracking parallel to the east coast of United States, heading toward New Jersey. On October 29, 2012, the storm turned west-northwest and made landfall near Atlantic City, N.J. The high winds and wind-driven storm surge caused massive damage along the entire coastline of New Jersey. Millions of people were left without power or communication networks. Many homes were completely destroyed. Sand dunes were eroded, and the barrier island at Mantoloking was breached, connecting the ocean with Barnegat Bay.Several days before the storm made landfall in New Jersey, the U.S. Geological Survey (USGS) made a decision to deploy a temporary network of storm-tide sensors and barometric pressure sensors from Virginia to Maine to supplement the existing USGS and National Oceanic and Atmospheric Administration (NOAA) networks of permanent tide monitoring stations. After the storm made landfall, the USGS conducted a sensor data recovery and high-water-mark collection campaign in cooperation with the Federal Emergency Management Agency (FEMA).Peak storm-tide elevations documented at USGS tide gages, tidal crest-stage gages, temporary storm sensor locations, and high-water-mark sites indicate the area from southern Monmouth County, N.J., north through Raritan Bay, N.J., had the highest peak storm-tide elevations during this storm. The USGS tide gages at Raritan River at South Amboy and Raritan Bay at Keansburg, part of the New Jersey Tide Telemetry System, each recorded peak storm-tide elevations of greater than 13 feet (ft)—more than 5 ft

  18. Offshore winds from a new generation of European satellites

    DEFF Research Database (Denmark)

    Badger, Merete; Karagali, Ioanna; Ahsbahs, Tobias Torben

    Offshore wind fields retrieved from satellite Synthetic Aperture Radar (SAR) observations can give valuable insight in the spatial wind variability over large areas. We can utilize this for mapping of wind farm wakes, wind resources, coastal wind speed gradients, storms, and other wind phenomena...... satellites and services could lower these barriers for applications in wind energy significantly. The Sentinel-1 A/B missions by the European Space Agency (ESA) deliver C-band SAR observations at an unprecedented coverage and spatial resolution. Over the seas of Europe, approximately 200 new acquisitions...... take place every day. DTU Wind Energy operates a system for processing of the raw SAR data to wind fields in near-real-time. The wind fields are available for download; for example by users in the wind energy community. Comparisons with mast and lidar observations have shown RMS errors of 1.3-1.5 m...

  19. Efficient Graffiti Image Retrieval

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chunlei; Wong, Pak C.; Ribarsky, William; Fan, Jianping

    2012-07-05

    Research of graffiti character recognition and retrieval, as a branch of traditional optical character recognition (OCR), has started to gain attention in recent years. We have investigated the special challenge of the graffiti image retrieval problem and propose a series of novel techniques to overcome the challenges. The proposed bounding box framework locates the character components in the graffiti images to construct meaningful character strings and conduct image-wise and semantic-wise retrieval on the strings rather than the entire image. Using real world data provided by the law enforcement community to the Pacific Northwest National Laboratory, we show that the proposed framework outperforms the traditional image retrieval framework with better retrieval results and improved computational efficiency.

  20. Offshore Wind Resources Assessment from Multiple Satellite Data and WRF Modeling over South China Sea

    DEFF Research Database (Denmark)

    Chang, Rui; Rong, Zhu; Badger, Merete

    2015-01-01

    offshore winds which can be used for offshore wind resource assessment. First, wind speeds retrieved from Synthetic Aperture Radar (SAR) and Scatterometer ASCAT images were validated against in situ measurements from seven coastal meteorological stations in South China Sea (SCS). The wind roses from...

  1. A numerical study of the impact of hurricane-induced storm surge on the Herbert Hoover Dike at Lake Okeechobee, Florida

    Science.gov (United States)

    Li, Yuepeng; Teng, Yi-Cheng; Kelly, David M.; Zhang, Keqi

    2016-12-01

    Hurricanes Frances, Jeanne, and Wilma passed over Lake Okeechobee, Florida, in September 2004 and October 2005, respectively. Strong winds caused a large surface seiche on the lake during all three storms. These storms resulted in erosion damage to the Herbert Hoover Dike (HHD) on Lake Okeechobee. In this paper, we use the Fully Adaptive Storm Tide (FAST) model (Kelly et al. in Coast Eng J 57(4):1-30, 2015, Nat Hazards 83:53-74, 2016) to study the response of the lake (in terms of the water level fluctuations and induced currents) to hurricanes Frances, Jeanne, and Wilma. Comparisons of the modeled surface water level with the observations are in overall good agreement for all three hurricanes. The modeled results suggest that the strong currents induced by the storm winds may be the dominant factor controlling the dike erosion observed at the lake side. The locations of erosion damage to the dike are consistent with the modeled high velocity zones during these three storms. In addition, numerical experiments have been conducted with eight hypothetical category 5 hurricanes approaching from different directions to investigate the erosion-prone zones related to high velocities in the vicinity of the dike. The results of the study should help to provide insight into vulnerable reaches of the HHD and inform flood control in the Okeechobee region.

  2. Improved Estimates of Moments and Winds from Radar Wind Profiler

    Energy Technology Data Exchange (ETDEWEB)

    Helmus, Jonathan [Argonne National Lab. (ANL), Argonne, IL (United States); Ghate, Virendra P. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-01-02

    The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) operates nine radar wind profilers (RWP) across its sites. These RWPs operate at 915 MHz or 1290 MHz frequency and report the first three moments of the Doppler spectrum. The operational settings of the RWP were modified in summer, 2015 to have single pulse length setting for the wind mode and two pulse length settings for the precipitation mode. The moments data collected during the wind mode are used to retrieve horizontal winds. The vendor-reported winds are available at variable time resolution (10 mins, 60 mins, etc.) and contain a significant amount of contamination due to noise and clutter. In this data product we have recalculated the moments and the winds from the raw radar Doppler spectrum and have made efforts to mitigate the contamination due to instrument noise in the wind estimates. Additionally, the moments and wind data has been reported in a harmonized layout identical for all locations and sites.

  3. High Resolution Hurricane Storm Surge and Inundation Modeling (Invited)

    Science.gov (United States)

    Luettich, R.; Westerink, J. J.

    2010-12-01

    Coastal counties are home to nearly 60% of the U.S. population and industry that accounts for over 16 million jobs and 10% of the U.S. annual gross domestic product. However, these areas are susceptible to some of the most destructive forces in nature, including tsunamis, floods, and severe storm-related hazards. Since 1900, tropical cyclones making landfall on the US Gulf of Mexico Coast have caused more than 9,000 deaths; nearly 2,000 deaths have occurred during the past half century. Tropical cyclone-related adjusted, annualized losses in the US have risen from 1.3 billion from 1949-1989, to 10.1 billion from 1990-1995, and $35.8 billion per year for the period 2001-2005. The risk associated with living and doing business in the coastal areas that are most susceptible to tropical cyclones is exacerbated by rising sea level and changes in the characteristics of severe storms associated with global climate change. In the five years since hurricane Katrina devastated the northern Gulf of Mexico Coast, considerable progress has been made in the development and utilization of high resolution coupled storm surge and wave models. Recent progress will be presented with the ADCIRC + SWAN storm surge and wave models. These tightly coupled models use a common unstructured grid in the horizontal that is capable of covering large areas while also providing high resolution (i.e., base resolution down to 20m plus smaller subgrid scale features such as sea walls and levees) in areas that are subject to surge and inundation. Hydrodynamic friction and overland winds are adjusted to account for local land cover. The models scale extremely well on modern high performance computers allowing rapid turnaround on large numbers of compute cores. The models have been adopted for FEMA National Flood Insurance Program studies, hurricane protection system design and risk analysis, and quasi-operational forecast systems for several regions of the country. They are also being evaluated as

  4. Passive microwave rainfall retrieval: A mathematical approach via sparse learning

    Science.gov (United States)

    Ebtehaj, M.; Lerman, G.; Foufoula-Georgiou, E.

    2013-12-01

    Detection and estimation of surface rainfall from spaceborne radiometric imaging is a challenging problem. The main challenges arise due to the nonlinear relationship of surface rainfall with its microwave multispectral signatures, the presence of noise, insufficient spatial resolution in observations, and the mixture of the earth surface and atmospheric radiations. A mathematical approach is presented for the detection and retrieval of surface rainfall from radiometric observations via supervised learning. In other words, we use a priori known libraries of high-resolution rainfall observations (e.g., obtained by an active radar) and their coincident spectral signatures (i.e., obtained by a radiometer) to design a mathematical model for rainfall retrieval. This model views the rainfall retrieval as a nonlinear inverse problem and relies on sparsity-promoting Bayesian inversion techniques. In this approach, we assume that small neighborhoods of the rainfall fields and their spectral signatures live on manifolds with similar local geometry and encode those neighborhoods in two joint libraries, the so-called rainfall and spectral dictionaries. We model rainfall passive microwave images by sparse linear combinations of the atoms of the spectral dictionary and then use the same representation coefficients to retrieve surface rain rates from the corresponding rainfall dictionary. The proposed methodology is examined by the use of spectral and rainfall dictionaries provided by the microwave imager (TMI) and precipitation radar (PR), aboard the Tropical Rainfall Measuring Mission (TRMM) satellite. Pros and cons of the presented approach are studied by extensive comparisons with the current operational rainfall algorithm of the TRMM satellite. Future extensions are also highlighted for potential application in the era of the Global Precipitation Measurement (GPM) mission. Comparing the retrieved rain rates for Hurricane Danielle 08/29/2010 (UTC 09:48:00). (Top panel) PR-2A

  5. Heat and turbulent kinetic energy budgets for surface layer cooling induced by the passage of Hurricane Frances (2004)

    Science.gov (United States)

    Huang, Peisheng; Sanford, Thomas B.; Imberger, JöRg

    2009-12-01

    Heat and turbulent kinetic energy budgets of the ocean surface layer during the passage of Hurricane Frances were examined using a three-dimensional hydrodynamic model. In situ data obtained with the Electromagnetic-Autonomous Profiling Explorer (EM-APEX) floats were used to set up the initial conditions of the model simulation and to compare to the simulation results. The spatial heat budgets reveal that during the hurricane passage, not only the entrainment in the bottom of surface mixed layer but also the horizontal water advection were important factors determining the spatial pattern of sea surface temperature. At the free surface, the hurricane-brought precipitation contributed a negligible amount to the air-sea heat exchange, but the precipitation produced a negative buoyancy flux in the surface layer that overwhelmed the instability induced by the heat loss to the atmosphere. Integrated over the domain within 400 km of the hurricane eye on day 245.71 of 2004, the rate of heat anomaly in the surface water was estimated to be about 0.45 PW (1 PW = 1015 W), with about 20% (0.09 PW in total) of this was due to the heat exchange at the air-sea interface, and almost all the remainder (0.36 PW) was downward transported by oceanic vertical mixing. Shear production was the major source of turbulent kinetic energy amounting 88.5% of the source of turbulent kinetic energy, while the rest (11.5%) was attributed to the wind stirring at sea surface. The increase of ocean potential energy due to vertical mixing represented 7.3% of the energy deposited by wind stress.

  6. Microphysical retrievals from simultaneous polarimetric and profiling radar observations

    Directory of Open Access Journals (Sweden)

    M. P. Morris

    2009-12-01

    Full Text Available The character of precipitation detected at the surface is the final product of many microphysical interactions in the cloud above, the combined effects of which may be characterized by the observed drop size distribution (DSD. This necessitates accurate retrieval of the DSD from remote sensing data, especially radar as it offers large areal coverage, high spatial resolution, and rigorous quality control and testing. Combined instrument observations with a UHF wind profiler, an S-band polarimetric weather radar, and a video disdrometer are analyzed for two squall line events occuring during the calendar year 2007. UHF profiler Doppler velocity spectra are used to estimate the DSD aloft, and are complemented by DSDs retrieved from an exponential model applied to polarimetric data. Ground truth is provided by the disdrometer. A complicating factor in the retrieval from UHF profiler spectra is the presence of ambient air motion, which can be corrected using the method proposed by Teshiba et al. (2009, in which a comparison between idealized Doppler spectra calculated from the DSDs retrieved from KOUN and those retrieved from contaminated wind profiler spectra is performed. It is found that DSDs measured using the distrometer at the surface and estimated using the wind profiler and polarimetric weather radar generally showed good agreement. The DSD retrievals using the wind profiler were improved when the estimates of the vertical wind were included into the analysis, thus supporting the method of Teshiba et al. (2009. Furthermore, the the study presents a method of investigating the time and height structure of DSDs.

  7. Retrieval options study

    Energy Technology Data Exchange (ETDEWEB)

    1980-03-01

    This Retrieval Options Study is part of the systems analysis activities of the Office of Nuclear Waste Isolation to develop the scientific and technological bases for radioactive waste repositories in various geologic media. The study considers two waste forms, high level waste and spent fuel, and defines various classes of waste retrieval and recovery. A methodology and data base are developed which allow the relative evaluation of retrieval and recovery costs and the following technical criteria: safety; technical feasibility; ease of retrieval; probable intact retrieval time; safeguards; monitoring; criticality; and licensability. A total of 505 repository options are defined and the cost and technical criteria evaluated utilizing a combination of facts and engineering judgments. The repositories evaluated are selected combinations of the following parameters: Geologic Media (salt, granite, basalt, shale); Retrieval Time after Emplacement (5 and 25 years); Emplacement Design (nominal hole, large hole, carbon steel canister, corrosion resistant canister, backfill in hole, nominal sleeves, thick wall sleeves); Emplacement Configuration (single vertical, multiple vertical, single horizontal, multiple horizontal, vaults; Thermal Considerations; (normal design, reduced density, once-through ventilation, recirculated ventilation); Room Backfill; (none, run-of-mine, early, 5 year delay, 25 year delay, decommissioned); and Rate of Retrieval; (same as emplacement, variably slower depending on repository/canister condition).

  8. Avifauna response to hurricanes: regional changes in community similarity

    Science.gov (United States)

    Chadwick D. Rittenhouse; Anna M. Pidgeon; Thomas P. Albright; Patrick D. Culbert; Murray K. Clayton; Curtis H. Flather; Chengquan Huang; Jeffrey G. Masek; Volker C. Radeloff

    2010-01-01

    Global climate models predict increases in the frequency and intensity of extreme climatic events such as hurricanes, which may abruptly alter ecological processes in forests and thus affect avian diversity. Developing appropriate conservation measures necessitates identifying patterns of avifauna response to hurricanes. We sought to answer two questions: (1) does...

  9. Long-term response of Caribbean palm forests to hurricanes

    Science.gov (United States)

    Ariel Lugo; J.L. Frangi

    2016-01-01

    We studied the response of Prestoea montana (Sierra Palm, hereafter Palm) brakes and a Palm floodplain forest to hurricanes in the Luquillo Experimental Forest in Puerto Rico. Over a span of 78 years, 3 hurricanes passed over the study sites for which we have 64 years of measurements for Palm brakes and 20 years for the Palm floodplain forest. For each stand, species...

  10. Resilience of Professional Counselors Following Hurricanes Katrina and Rita

    Science.gov (United States)

    Lambert, Simone F.; Lawson, Gerard

    2013-01-01

    Professional counselors who provided services to those affected by Hurricanes Katrina and Rita completed the K6+ (screen for severe mental illness), the Posttraumatic Growth Inventory, and the Professional Quality of Life Scale. Results indicated that participants who survived the hurricanes had higher levels of posttraumatic growth than…

  11. The Business of Intimacy: Hurricanes and Howling Wolves

    Science.gov (United States)

    Paley, Vivian

    2006-01-01

    The date is September 9, 2005. This article is set in a rural Wisconsin community, a thousand miles north of New Orleans, where Hurricane Katrina is about to make landfall. The four- and five- year- olds in Mrs. Olson's classroom have never experienced a hurricane or seen flood waters rise to cover the farms and houses they know, but they cannot…

  12. Resilience of Professional Counselors Following Hurricanes Katrina and Rita

    Science.gov (United States)

    Lambert, Simone F.; Lawson, Gerard

    2013-01-01

    Professional counselors who provided services to those affected by Hurricanes Katrina and Rita completed the K6+ (screen for severe mental illness), the Posttraumatic Growth Inventory, and the Professional Quality of Life Scale. Results indicated that participants who survived the hurricanes had higher levels of posttraumatic growth than…

  13. Teacher Guidelines for Helping Students after a Hurricane

    Science.gov (United States)

    National Child Traumatic Stress Network, 2013

    2013-01-01

    Being in a hurricane can be very frightening, and the days, weeks, and months following the storm can be very stressful. Most families recover over time, especially with the support of relatives, friends, and their community. But different families may have different experiences during and after a hurricane, and how long it takes them to recover…

  14. Post-hurricane forest damage assessment using satellite remote sensing

    Science.gov (United States)

    W. Wang; J.J. Qu; X. Hao; Y. Liu; J.A. Stanturf

    2010-01-01

    This study developed a rapid assessment algorithm for post-hurricane forest damage estimation using moderate resolution imaging spectroradiometer (MODIS) measurements. The performance of five commonly used vegetation indices as post-hurricane forest damage indicators was investigated through statistical analysis. The Normalized Difference Infrared Index (NDII) was...

  15. Mass Media Use by College Students during Hurricane Threat

    Science.gov (United States)

    Piotrowski, Chris

    2015-01-01

    There is a dearth of studies on how college students prepare for the threat of natural disasters. This study surveyed college students' preferences in mass media use prior to an approaching hurricane. The convenience sample (n = 76) were from a university located in the hurricane-prone area of the central Gulf of Mexico coast. Interestingly,…

  16. Experience of Hurricane Katrina and Reported Intimate Partner Violence

    Science.gov (United States)

    Harville, Emily W.; Taylor, Catherine A.; Tesfai, Helen; Xiong, Xu; Buekens, Pierre

    2011-01-01

    Intimate partner violence (IPV) has been associated with stress, but few studies have examined the effect of natural disaster on IPV. In this study, the authors examine the relationship between experience of Hurricane Katrina and reported relationship aggression and violence in a cohort of 123 postpartum women. Hurricane experience is measured…

  17. Retention of Displaced Students after Hurricanes Katrina and Rita

    Science.gov (United States)

    Coco, Joshua Christian

    2017-01-01

    The purpose of the study was to investigate the strategies that university leaders implemented to improve retention of displaced students in the aftermaths of Hurricanes Katrina and Rita. The universities that participated in this study admitted displaced students after Hurricanes Katrina and Rita. This study utilized a qualitative…

  18. Teacher Guidelines for Helping Students after a Hurricane

    Science.gov (United States)

    National Child Traumatic Stress Network, 2013

    2013-01-01

    Being in a hurricane can be very frightening, and the days, weeks, and months following the storm can be very stressful. Most families recover over time, especially with the support of relatives, friends, and their community. But different families may have different experiences during and after a hurricane, and how long it takes them to recover…

  19. Experience of Hurricane Katrina and Reported Intimate Partner Violence

    Science.gov (United States)

    Harville, Emily W.; Taylor, Catherine A.; Tesfai, Helen; Xiong, Xu; Buekens, Pierre

    2011-01-01

    Intimate partner violence (IPV) has been associated with stress, but few studies have examined the effect of natural disaster on IPV. In this study, the authors examine the relationship between experience of Hurricane Katrina and reported relationship aggression and violence in a cohort of 123 postpartum women. Hurricane experience is measured…

  20. On the Impact Angle of Hurricane Sandy's New Jersey Landfall

    Science.gov (United States)

    Hall, Timothy M.; Sobel, Adam H.

    2013-01-01

    Hurricane Sandy's track crossed the New Jersey coastline at an angle closer to perpendicular than any previous hurricane in the historic record, one of the factors contributing to recordsetting peak-water levels in parts of New Jersey and New York. To estimate the occurrence rate of Sandy-like tracks, we use a stochastic model built on historical hurricane data from the entire North Atlantic to generate a large sample of synthetic hurricanes. From this synthetic set we calculate that under long-term average climate conditions, a hurricane of Sandy's intensity or greater (category 1+) makes NJ landfall at an angle at least as close to perpendicular as Sandy's at an average annual rate of 0.0014 yr-1 (95% confidence range 0.0007 to 0.0023); i.e., a return period of 714 years (95% confidence range 435 to 1429).

  1. Hurricane Sandy: Shared Trauma and Therapist Self-Disclosure.

    Science.gov (United States)

    Rao, Nyapati; Mehra, Ashwin

    2015-01-01

    Hurricane Sandy was one of the most devastating storms to hit the United States in history. The impact of the hurricane included power outages, flooding in the New York City subway system and East River tunnels, disrupted communications, acute shortages of gasoline and food, and a death toll of 113 people. In addition, thousands of residences and businesses in New Jersey and New York were destroyed. This article chronicles the first author's personal and professional experiences as a survivor of the hurricane, more specifically in the dual roles of provider and trauma victim, involving informed self-disclosure with a patient who was also a victim of the hurricane. The general analytic framework of therapy is evaluated in the context of the shared trauma faced by patient and provider alike in the face of the hurricane, leading to important implications for future work on resilience and recovery for both the therapist and patient.

  2. Near-real-time Forensic Disaster Analysis: experiences from hurricane Sandy

    Science.gov (United States)

    Kunz, Michael; Mühr, Bernhard; Schröter, Kai; Kunz-Plapp, Tina; Daniell, James; Khazai, Bijan; Wenzel, Friedemann; Vannieuwenhuyse, Marjorie; Comes, Tina; Münzberg, Thomas; Elmer, Florian; Fohringer, Joachim; Lucas, Christian; Trieselmann, Werner; Zschau, Jochen

    2013-04-01

    Hurricane Sandy was the last tropical cyclone of the 2012 Northern Atlantic Hurricane season that made landfall. It moved on an unusual track from the Caribbean to the East Coast of the United States from 24 to 30 October as a Category 1 and 2 Hurricane according to the Saffir-Simpson Scale. Along its path, the severe storm event caused widespread damage including almost 200 fatalities. In the early hours of 30 October, Sandy made landfall near Atlantic City, N.J. Sandy was an extraordinary event due to its multihazard nature and several cascading effects in the aftermath. From the hydro-meteorological perspective, most unusual was the very large spatial extent of up to 1,700 km. High wind speeds were associated with record breaking storm surges at the U.S. Mid- Atlantic and New England Coast during high (astronomical) tide, leading to widespread flooding. Though Sandy was not the most severe storm event in terms of wind speed and precipitation, the impact in the U.S. was enormous with total damage estimates of up to 90 billion US (own estimate from Dec. 2012). Although much better data emerge weeks after such an event, the Forensic Disaster Analysis (FDA) Task Force of the Center for Disaster Management and Risk Reduction Technology (CEDIM) made an effort to obtain a comprehensive and holistic overview of the causes, hazardous effects and consequences associated with Sandy immediately after landfall at the U.S. coast on 30 October 2012. This was done in an interdisciplinary way by collecting and compiling scattered and distributed information from available databases and sources via the Internet, by applying own methodologies and models for near-real time analyses developed in recent years, and by expert knowledge. This contribution gives an overview about the CEDIM-FDA analyses' results. It describes the situation that led to the extraordinary event, highlights the interaction of the tropical cyclone with other hydro-meteorological events, and examines the

  3. Asymmetric oceanic response to a hurricane: Deep water observations during Hurricane Isaac

    Science.gov (United States)

    Spencer, Laura J.; DiMarco, Steven F.; Wang, Zhankun; Kuehl, Joseph J.; Brooks, David A.

    2016-10-01

    The eye of Hurricane Isaac passed through the center of an array of six deep water water-column current meter moorings deployed in the northern Gulf of Mexico. The trajectory of the hurricane provided for a unique opportunity to quantify differences in the full water-column oceanic response to a hurricane to the left and right of the hurricane trajectory. Prior to the storm passage, relative vorticity on the right side of the hurricane was strongly negative, while on the left, relative vorticity was positive. This resulted in an asymmetry in the near-inertial frequencies oceanic response at depth and horizontally. A shift in the response to a slightly larger inertial frequencies ˜1.11f was observed and verified by theory. Additionally, the storm passage coincided with an asymmetric change in relative vorticity in the upper 1000 m, which persisted for ˜15 inertial periods. Vertical propagation of inertial energy was estimated at 29 m/d, while horizontal propagation at this frequency was approximately 5.7 km/d. Wavelet analysis showed two distinct subinertial responses, one with a period of 2-5 days and another with a period of 5-12 days. Analysis of the subinertial bands reveals that the spatial and temporal scales are shorter and less persistent than the near-inertial variance. As the array is geographically located near the site of the Deep Water Horizon oil spill, the spatial and temporal scales of response have significant implications for the fate, transport, and distribution of hydrocarbons following a deep water spill event.

  4. The effect of foam on waves and the aerodynamic roughness of the water surface at high winds

    Science.gov (United States)

    Troitskaya, Yuliya; Vdovin, Maxim; Sergeev, Daniil; Kandaurov, Alexander

    2017-04-01

    Air-sea coupling at extreme winds is of special interest now in connection with the problem of explanation of the sea surface drag saturation at the wind speed exceeding 30 m/s. The idea on saturation (and even reduction) of the coefficient of aerodynamic resistance of the sea surface at hurricane wind speed first suggested in [1] on the basis of theoretical analysis of sensitivity of maximum wind speed in a hurricane to the ratio of the enthalpy and momentum exchange coefficients was then confirmed by a number of field (e.g.[2]) and laboratory [3] experiments, which showed that the sea surface drag coefficient was significantly reduced in comparison with the parameterization obtained at moderate to strong wind conditions. The theoretical explanations of the effect of the sea surface drag reduction exploit either peculiarities of the air flow over breaking waves (e.g.[4,5]) or the effect of sea drops and spray on the wind-wave momentum exchange (e.g. [6,7]). Recently an alternative hypothesis was suggested in [8], where the surface drag reduction in hurricanes was explained by the influence of foam covering sea surface on its aerodynamic roughness. This paper describes a series of laboratory experiments in Thermostratified Wind-Wave Tank (TSWiWaT) of IAP directed to investigation of the foam impact on the short-wave part of the surface waves and the momentum exchange in the atmospheric boundary layer at high winds in the range of equivalent 10-m wind speed from 12 to 38 m/s. A special foam generator was designed for these experiments. The air flow parameters were retrieved from measurements of the velocity profiles. The frequency-wavenumber spectra of surface waves were retrieved from the measurements of water surface elevation by the array 3-channel wave gauge. Foam coverage of water surface was controlled by video filming of the water surface. The results of measurements were compared with predictions of the quasi-linear model of atmospheric boundary layer over

  5. Wind class sampling of satellite SAR imagery for offshore wind resource mapping

    DEFF Research Database (Denmark)

    Badger, Merete; Badger, Jake; Nielsen, Morten

    2010-01-01

    High-resolution wind fields retrieved from satellite synthetic aperture radar (SAR) imagery are combined for mapping of wind resources offshore where site measurements are costly and sparse. A new sampling strategy for the SAR scenes is introduced, based on a method for statistical-dynamical down......High-resolution wind fields retrieved from satellite synthetic aperture radar (SAR) imagery are combined for mapping of wind resources offshore where site measurements are costly and sparse. A new sampling strategy for the SAR scenes is introduced, based on a method for statistical......-dynamical downscaling of large-scale wind conditions using a set of wind classes that describe representative wind situations. One or more SAR scenes are then selected to represent each wind class and the classes are weighted according to their frequency of occurrence. The wind class methodology was originally...... developed for mesoscale modeling of wind resources. Its performance in connection with sampling of SAR scenes is tested against two sets of random SAR samples and meteorological observations at three sites in the North Sea during 2005–08. Predictions of the mean wind speed and the Weibull scale parameter...

  6. Contrast validation test for retrieval method of high frequency ground wave radar

    Institute of Scientific and Technical Information of China (English)

    WANG Hailong; GUO Peifang; HAN Shuzong; XIE Qiang; ZHOU Liangming

    2005-01-01

    In this paper, on the basis of the working principles of high frequency ground wave radar for retrieval of ocean wave and sea wind elements were used to systematically study the data obtained from contrast validation test in Zhoushan sea area of Zhejiang Province on Oct. 2000, to validate the accuracy of OSMAR2000for wave and wind parameters, and to analyze the possible error caused when using OSMAR2000 to retrieve ocean parameters.

  7. Hurricane impacts on a pair of coastal forested watersheds: implications of selective hurricane damage to forest structure and streamflow dynamics

    Science.gov (United States)

    A.D. Jayakaran; T.M. Williams; H. Ssegane; D.M. Amatya; B. Song; C.C. Trettin

    2014-01-01

    Hurricanes are infrequent but influential disruptors of ecosystem processes in the southeastern Atlantic and Gulf coasts. Every southeastern forested wetland has the potential to be struck by a tropical cyclone. We examined the impact of Hurricane Hugo on two paired coastal South Carolina watersheds in terms of streamflow and vegetation dynamics, both before and after...

  8. Retrieval of Atmospheric and Oceanic Parameters and the Relevant Numerical Calculation

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    It is well known that retrieval of parameters is usually ill-posed and highly nonlinear, so parameter retrieval problems are very difficult. There are still many important theoretical issues under research,although great success has been achieved in data assimilation in meteorology and oceanography. This paper reviews the recent research on parameter retrieval, especially that of the authors. First, some concepts and issues of parameter retrieval are introduced and the state-of-the-art parameter retrieval technology in meteorology and oceanography is reviewed briefly, and then atmospheric and oceanic parameters are retrieved using the variational data assimilation method combined with the regularization techniques in four examples: retrieval of the vertical eddy diffusion coefficient; of the turbulivity of the atmospheric boundary layer; of wind from Doppler radar data, and of the physical process parameters. Model parameter retrieval with global and local observations is also introduced.

  9. Foreign Body Retrieval

    Medline Plus

    Full Text Available ... of page What are some common uses of the procedure? Foreign body retrieval is used to remove ... the foreign body. top of page What does the equipment look like? A variety of x-ray ...

  10. RETRIEVAL EQUIPMENT DESCRIPTIONS

    Energy Technology Data Exchange (ETDEWEB)

    J. Steinhoff

    1997-08-25

    The objective and the scope of this document are to list and briefly describe the major mobile equipment necessary for waste package (WP) retrieval from the proposed subsurface nuclear waste repository at Yucca Mountain. Primary performance characteristics and some specialized design features of the equipment are explained and summarized in the individual subsections of this document. There are no quality assurance requirements or QA controls in this document. Retrieval under normal conditions is accomplished with the same fleet of equipment as is used for emplacement. Descriptions of equipment used for retrieval under normal conditions is found in Emplacement Equipment Descriptions, DI: BCAF00000-01717-5705-00002 (a document in progress). Equipment used for retrieval under abnormal conditions is addressed in this document and consists of the following: (1) Inclined Plane Hauler; (2) Bottom Lift Transporter; (3) Load Haul Dump (LHD) Loader; (4) Heavy Duty Forklift for Emplacement Drifts; (5) Covered Shuttle Car; (6) Multipurpose Vehicle; and (7) Scaler.

  11. Information retrieval system

    Science.gov (United States)

    Berg, R. F.; Holcomb, J. E.; Kelroy, E. A.; Levine, D. A.; Mee, C., III

    1970-01-01

    Generalized information storage and retrieval system capable of generating and maintaining a file, gathering statistics, sorting output, and generating final reports for output is reviewed. File generation and file maintenance programs written for the system are general purpose routines.

  12. Foreign Body Retrieval

    Medline Plus

    Full Text Available ... object is solid or filled with fluid). In medicine, ultrasound is used to detect changes in appearance, ... Anesthesia Safety X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Videos related to Foreign Body Retrieval ...

  13. Content Based Video Retrieval

    Directory of Open Access Journals (Sweden)

    B. V. Patel

    2012-10-01

    Full Text Available Content based video retrieval is an approach for facilitating the searching and browsing of large image collections over World Wide Web. In this approach, video analysis is conducted on low level visual properties extracted from video frame. We believed that in order to create an effective video retrieval system, visual perception must be taken into account. We conjectured that a technique which employs multiple features for indexing and retrieval would be more effective in the discrimination and search tasks of videos. In order to validate this claim, content based indexing and retrieval systems were implemented using color histogram, various texture features and other approaches. Videos were stored in Oracle 9i Database and a user study measured correctness of response.

  14. Foreign Body Retrieval

    Medline Plus

    Full Text Available ... of page What are some common uses of the procedure? Foreign body retrieval is used to remove ... the foreign body. top of page What does the equipment look like? A variety of x-ray ...

  15. Foreign Body Retrieval

    Medline Plus

    Full Text Available ... surrounding tissues. top of page What are some common uses of the procedure? Foreign body retrieval is ... air-filled lungs, are poorly suited for ultrasound. Common equipment for identifying and removing foreign bodies from ...

  16. Integrated Hydrologic Validation to Improve Physical Precipitation Retrievals for GPM

    Science.gov (United States)

    Peters-Lidard, C. D.; Harrison, K. W.; Tian, Y.; Kumar, S.

    2011-12-01

    One of the five scientific objectives for GPM is to "Improve hydrological modeling and prediction", including advancing prediction skill for high-impact hazards such as floods, droughts, landslides and landfalling hurricanes. Given the focus on land hydrology, and the range of hydrologic regimes targeted by GPM, it follows that a hydrologically-oriented ground validation program that covers these regimes from both the physical retrieval and the hydrological prediction perspectives is required for the successful application of GPM to land hydrology. In order to investigate the robustness of both hydrologic model predictions and physical precipitation retrievals, this talk will present recent evaluations of skill in land surface hydrologic models forced with TRMM-era multisensor products, with and without land data assimilation. In addition to LSM skill, we will also demonstrate how physical precipitation retrievals can be supported by land surface emissivity and temperature estimates obtained by coupling microwave emission models (e.g., the Joint Center for Satellite Data Assimilation Community Radiative Transfer Model CRTM and the European Center for Medium-Range Weather Forecasting's Community Microwave Emission Model CMEM) to the land surface models in the Land Information System (LIS; http://lis.gsfc.nasa.gov). Evaluation at multiple frequencies, with and without land data assimilation, demonstrates the critical impact of certain real-time ancillary data (e.g., snow cover) on the microwave background states required for physical retrievals.

  17. Evaluating personal information retrieval

    OpenAIRE

    Kelly, Liadh; Bunbury, Paul; Jones, Gareth J.F.

    2012-01-01

    Evaluation of personal search over an individual’s personal information space on the desktop or elsewhere is problematic for reasons relating both to the personal and private nature of the data and the associated personal information needs of collection owners. Indeed challenges associated with evaluation in this space are recognised as one of the key factors hindering the development of research in personal information retrieval. We present the “personal information retrieval evaluatio...

  18. Using Satellite SAR to Characterize the Wind Flow around Offshore Wind Farms

    Directory of Open Access Journals (Sweden)

    Charlotte Bay Hasager

    2015-06-01

    Full Text Available Offshore wind farm cluster effects between neighboring wind farms increase rapidly with the large-scale deployment of offshore wind turbines. The wind farm wakes observed from Synthetic Aperture Radar (SAR are sometimes visible and atmospheric and wake models are here shown to convincingly reproduce the observed very long wind farm wakes. The present study mainly focuses on wind farm wake climatology based on Envisat ASAR. The available SAR data archive covering the large offshore wind farms at Horns Rev has been used for geo-located wind farm wake studies. However, the results are difficult to interpret due to mainly three issues: the limited number of samples per wind directional sector, the coastal wind speed gradient, and oceanic bathymetry effects in the SAR retrievals. A new methodology is developed and presented. This method overcomes effectively the first issue and in most cases, but not always, the second. In the new method all wind field maps are rotated such that the wind is always coming from the same relative direction. By applying the new method to the SAR wind maps, mesoscale and microscale model wake aggregated wind-fields results are compared. The SAR-based findings strongly support the model results at Horns Rev 1.

  19. Impact of 4DVAR Assimilation of AIRS Total Column Ozone Observations on the Simulation of Hurricane Earl

    Institute of Scientific and Technical Information of China (English)

    刘寅; 邹晓蕾

    2015-01-01

    The Atmospheric Infrared Sounder (AIRS) provides twice-daily global observations of brightness tem-perature, which can be used to retrieve the total column ozone with high spatial and temporal resolution. In order to apply the AIRS ozone data to numerical prediction of tropical cyclones, a four-dimensional vari-ational (4DVAR) assimilation scheme on selected model levels is adopted and implemented in the mesoscale non-hydrostatic model MM5. Based on the correlation between total column ozone and potential vorticity (PV), the observation operator of each level is established and fi ve levels with highest correlation coeffi cients are selected for the 4DVAR assimilation of the AIRS total column ozone observations. The results from the numerical experiments using the proposed assimilation scheme for Hurricane Earl show that the ozone data assimilation aff ects the PV distributions with more mesoscale information at high levels fi rst and then infl uences those at middle and low levels through the so-called asymmetric penetration of PV anomalies. With the AIRS ozone data being assimilated, the warm core of Hurricane Earl is intensifi ed, resulting in the improvement of other fi elds near the hurricane center. The track prediction is improved mainly due to adjustment of the steering fl ows in the assimilation experiment.

  20. Shortcomings in climate model simulations of the ENSO-Atlantic hurricane teleconnection

    Energy Technology Data Exchange (ETDEWEB)

    Shaman, Jeffrey [Columbia University, Department of Environmental Health Sciences, Mailman School of Public Health, New York, NY (United States); Columbia University, International Research Institute for Climate and Society, Palisades, NY (United States); Maloney, Eric D. [Colorado State University, Department of Atmospheric Science, Fort Collins, CO (United States)

    2012-05-15

    A number of recent studies have used model projections to investigate how the North Atlantic environment in which tropical storms develop, as well as hurricane activity itself, might change in a warming world. However, accurate projection of the North Atlantic environment in the future requires, at a minimum, accurate representation of its mean state and variability in the current climate. Here we examine one metric of Atlantic basin tropical cyclone variability - its well-documented association with the El Nino-Southern Oscillation (ENSO) - in reanalyses and Intergovernmental Panel of Climate Change (IPCC) 4th Assessment Report (AR4) twentieth century and Atmospheric Model Intercomparison Project simulations. We find that no individual model provides consistently good representation of ENSO-related variability in the North Atlantic for variables relevant to hurricane activity (e.g. vertical wind shear, genesis potential). Model representation of the ENSO influence is biased due to both inaccurate representation of ENSO itself and inaccurate representation of the response to ENSO within the North Atlantic. Among variables examined, ENSO impacts on vertical wind shear and potential intensity were most poorly simulated. The multi-model ensemble mean representation of North Atlantic environmental response to ENSO is better matched with reanalysis than most individual AR4 models; however, this mean response still possesses some considerable bias. A few models do provide comparable or slightly better simulation of these ENSO-North Atlantic teleconnections than the multi-model ensemble average; however, for both the multi-model mean and the well performing models, good simulation of the ENSO-related variability of genesis potential within portions of the North Atlantic does not stem from accurate representation of the ENSO-related variability of the individual environmental variables that comprise genesis potential (e.g. vertical wind shear, potential intensity). (orig.)

  1. Monitoring Inland Storm Surge and Flooding from Hurricane Ike in Texas and Louisiana, September 2008

    Science.gov (United States)

    East, Jeffery W.; Turco, Michael J.; Mason, Jr., Robert R.

    2008-01-01

    The U.S. Geological Survey (USGS) deployed a temporary monitoring network of 117 pressure transducers (sensors) at 65 sites over an area of about 5,000 square miles to record the timing, areal extent, and magnitude of inland hurricane storm surge and coastal flooding generated by Hurricane Ike, which struck southeastern Texas and southwestern Louisiana September 12-13, 2008. Fifty-six sites were in Texas and nine were in Louisiana. Sites were categorized as surge, riverine, or beach/wave on the basis of proximity to the Gulf Coast. One-hundred five sensors from 59 sites (fig. 1) were recovered; 12 sensors from six sites either were lost during the storm or were not retrieved. All 59 sites (41 surge, 10 riverine, 8 beach/wave) had sensors to record water pressure (fig. 2), which is expressed as water level in feet above North American Vertical Datum of 1988 (NAVD88), and 46 sites had an additional sensor to record barometric pressure, expressed in pounds per square inch. Figure 3 shows an example of water level and barometric pressure over time recorded by sensors during the storm.

  2. Hurricane Sandy science plan: coastal impact assessments

    Science.gov (United States)

    Stronko, Jakob M.

    2013-01-01

    Hurricane Sandy devastated some of the most heavily populated eastern coastal areas of the Nation. With a storm surge peaking at more than 19 feet, the powerful landscape-altering destruction of Hurricane Sandy is a stark reminder of why the Nation must become more resilient to coastal hazards. In response to this natural disaster, the U.S. Geological Survey (USGS) received a total of $41.2 million in supplemental appropriations from the Department of the Interior (DOI) to support response, recovery, and rebuilding efforts. These funds support a science plan that will provide critical scientific information necessary to inform management decisions for recovery of coastal communities, and aid in preparation for future natural hazards. This science plan is designed to coordinate continuing USGS activities with stakeholders and other agencies to improve data collection and analysis that will guide recovery and restoration efforts. The science plan is split into five distinct themes: coastal topography and bathymetry, impacts to coastal beaches and barriers, impacts of storm surge, including disturbed estuarine and bay hydrology, impacts on environmental quality and persisting contaminant exposures, impacts to coastal ecosystems, habitats, and fish and wildlife. This fact sheet focuses assessing impacts to coastal beaches and barriers.

  3. Estimating hurricane hazards using a GIS system

    Directory of Open Access Journals (Sweden)

    A. Taramelli

    2008-08-01

    Full Text Available This paper develops a GIS-based integrated approach to the Multi-Hazard model method, with reference to hurricanes. This approach has three components: data integration, hazard assessment and score calculation to estimate elements at risk such as affected area and affected population. First, spatial data integration issues within a GIS environment, such as geographical scales and data models, are addressed. Particularly, the integration of physical parameters and population data is achieved linking remotely sensed data with a high resolution population distribution in GIS. In order to assess the number of affected people, involving heterogeneous data sources, the selection of spatial analysis units is basic. Second, specific multi-hazard tasks, such as hazard behaviour simulation and elements at risk assessment, are composed in order to understand complex hazard and provide support for decision making. Finally, the paper concludes that the integrated approach herein presented can be used to assist emergency management of hurricane consequences, in theory and in practice.

  4. A Simulation Tool for Hurricane Evacuation Planning

    Directory of Open Access Journals (Sweden)

    Daniel J. Fonseca

    2009-01-01

    Full Text Available Atlantic hurricanes and severe tropical storms are a serious threat for the communities in the Gulf of Mexico region. Such storms are violent and destructive. In response to these dangers, coastal evacuation may be ordered. This paper describes the development of a simulation model to analyze the movement of vehicles through I-65, a major US Interstate highway that runs north off the coastal City of Mobile, Alabama, towards the State of Tennessee, during a massive evacuation originated by a disastrous event such a hurricane. The constructed simulation platform consists of a primary and two secondary models. The primary model is based on the entry of vehicles from the 20 on-ramps to I-65. The two secondary models assist the primary model with related traffic events such as car breakdowns and accidents, traffic control measures, interarrival signaling, and unforeseen emergency incidents, among others. Statistical testing was performed on the data generated by the simulation model to indentify variation in relevant traffic variables affecting the timely flow of vehicles travelling north. The performed statistical analysis focused on the closing of alternative on-ramps throughout the Interstate.

  5. Weathering the storm: hurricanes and birth outcomes.

    Science.gov (United States)

    Currie, Janet; Rossin-Slater, Maya

    2013-05-01

    A growing literature suggests that stressful events in pregnancy can have negative effects on birth outcomes. Some of the estimates in this literature may be affected by small samples, omitted variables, endogenous mobility in response to disasters, and errors in the measurement of gestation, as well as by a mechanical correlation between longer gestation and the probability of having been exposed. We use millions of individual birth records to examine the effects of exposure to hurricanes during pregnancy, and the sensitivity of the estimates to these econometric problems. We find that exposure to a hurricane during pregnancy increases the probability of abnormal conditions of the newborn such as being on a ventilator more than 30min and meconium aspiration syndrome (MAS). Although we are able to reproduce previous estimates of effects on birth weight and gestation, our results suggest that measured effects of stressful events on these outcomes are sensitive to specification and it is preferable to use more sensitive indicators of newborn health. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Dynamics and Predictability of Hurricane Dolly (2008)

    Science.gov (United States)

    Fang, J.; Zhang, F.; Weng, Y.

    2008-12-01

    Through several cloud-resolving simulations with the Weather Research and Forecast (WRF-ARW) model, this study examines the dynamics and predictability of Hurricane Dolly (2008) with an emphasis on its initial development (around the time being declared as a tropical storm) and subsequent rapid intensification entering into the Gulf of Mexico. These WRF simulations include three that are directly initialized with the operational NCEP GFS analyses at 06, 12 and 18Z 20 July 2008, respectively (EXP06, EXP12, EXP18) and another the same as EXP06 except that the airborne Doppler velocity observations by a NOAA P3 aircraft during 12-15Z are assimilated with an ensemble-Kalman filter (ENKF06). Among the four experiments, only EXP06 fails to capture the rapid intensification and fails to develop the tropical storm into a mature hurricane. Preliminary comparison between the simulated fields of EXP06 and the GFS analysis at 12Z (e.g., IC of EXP12) indicates that large scale features favorable to the tropical cyclogenesis cannot be properly simulated in EXP06. The initial disturbance is rather weak positioned too far south-west that is far away from the primary convective. However, after the airborne radar data during 12-15Z are assimilated into the model, (from EXP06 into ENKF06), the ENKF06 simulation is greatly improved in that a well-organized warm-core vortex appears at the low level right after radar assimilation, which subsequently developed into a hurricane consistent with timing, track and intensity of observations. Interestingly, there are significant differences in the initial vortex position, structure and evolution among the three simulations (EXP12, EXP18, ENKF06) that all eventually develop a mature hurricane along the observed track (before landfall) with right timing after enters into the Gulf of Mexico. At 18Z 20 July, there is no apparent initial low-level cyclonic vortex in EXP12 and EXP18 (that is assimilated into ENKF06 due to radar observations

  7. The Storm Surge and Sub-Grid Inundation Modeling in New York City during Hurricane Sandy

    Directory of Open Access Journals (Sweden)

    Harry V. Wang

    2014-03-01

    Full Text Available Hurricane Sandy inflicted heavy damage in New York City and the New Jersey coast as the second costliest storm in history. A large-scale, unstructured grid storm tide model, Semi-implicit Eulerian Lagrangian Finite Element (SELFE, was used to hindcast water level variation during Hurricane Sandy in the mid-Atlantic portion of the U.S. East Coast. The model was forced by eight tidal constituents at the model’s open boundary, 1500 km away from the coast, and the wind and pressure fields from atmospheric model Regional Atmospheric Modeling System (RAMS provided by Weatherflow Inc. The comparisons of the modeled storm tide with the NOAA gauge stations from Montauk, NY, Long Island Sound, encompassing New York Harbor, Atlantic City, NJ, to Duck, NC, were in good agreement, with an overall root mean square error and relative error in the order of 15–20 cm and 5%–7%, respectively. Furthermore, using large-scale model outputs as the boundary conditions, a separate sub-grid model that incorporates LIDAR data for the major portion of the New York City was also set up to investigate the detailed inundation process. The model results compared favorably with USGS’ Hurricane Sandy Mapper database in terms of its timing, local inundation area, and the depth of the flooding water. The street-level inundation with water bypassing the city building was created and the maximum extent of horizontal inundation was calculated, which was within 30 m of the data-derived estimate by USGS.

  8. Rapid shelf-wide cooling response of a stratified coastal ocean to hurricanes

    Science.gov (United States)

    Seroka, Greg; Miles, Travis; Xu, Yi; Kohut, Josh; Schofield, Oscar; Glenn, Scott

    2017-06-01

    Large uncertainty in the predicted intensity of tropical cyclones (TCs) persists compared to the steadily improving skill in the predicted TC tracks. This intensity uncertainty has its most significant implications in the coastal zone, where TC impacts to populated shorelines are greatest. Recent studies have demonstrated that rapid ahead-of-eye-center cooling of a stratified coastal ocean can have a significant impact on hurricane intensity forecasts. Using observation-validated, high-resolution ocean modeling, the stratified coastal ocean cooling processes observed in two U.S. Mid-Atlantic hurricanes were investigated: Hurricane Irene (2011)—with an inshore Mid-Atlantic Bight (MAB) track during the late summer stratified coastal ocean season—and Tropical Storm Barry (2007)—with an offshore track during early summer. For both storms, the critical ahead-of-eye-center depth-averaged force balance across the entire MAB shelf included an onshore wind stress balanced by an offshore pressure gradient. This resulted in onshore surface currents opposing offshore bottom currents that enhanced surface to bottom current shear and turbulent mixing across the thermocline, resulting in the rapid cooling of the surface layer ahead-of-eye-center. Because the same baroclinic and mixing processes occurred for two storms on opposite ends of the track and seasonal stratification envelope, the response appears robust. It will be critical to forecast these processes and their implications for a wide range of future storms using realistic 3-D coupled atmosphere-ocean models to lower the uncertainty in predictions of TC intensities and impacts and enable coastal populations to better respond to increasing rapid intensification threats in an era of rising sea levels.

  9. Rapid shelf‐wide cooling response of a stratified coastal ocean to hurricanes

    Science.gov (United States)

    Miles, Travis; Xu, Yi; Kohut, Josh; Schofield, Oscar; Glenn, Scott

    2017-01-01

    Abstract Large uncertainty in the predicted intensity of tropical cyclones (TCs) persists compared to the steadily improving skill in the predicted TC tracks. This intensity uncertainty has its most significant implications in the coastal zone, where TC impacts to populated shorelines are greatest. Recent studies have demonstrated that rapid ahead‐of‐eye‐center cooling of a stratified coastal ocean can have a significant impact on hurricane intensity forecasts. Using observation‐validated, high‐resolution ocean modeling, the stratified coastal ocean cooling processes observed in two U.S. Mid‐Atlantic hurricanes were investigated: Hurricane Irene (2011)—with an inshore Mid‐Atlantic Bight (MAB) track during the late summer stratified coastal ocean season—and Tropical Storm Barry (2007)—with an offshore track during early summer. For both storms, the critical ahead‐of‐eye‐center depth‐averaged force balance across the entire MAB shelf included an onshore wind stress balanced by an offshore pressure gradient. This resulted in onshore surface currents opposing offshore bottom currents that enhanced surface to bottom current shear and turbulent mixing across the thermocline, resulting in the rapid cooling of the surface layer ahead‐of‐eye‐center. Because the same baroclinic and mixing processes occurred for two storms on opposite ends of the track and seasonal stratification envelope, the response appears robust. It will be critical to forecast these processes and their implications for a wide range of future storms using realistic 3‐D coupled atmosphere‐ocean models to lower the uncertainty in predictions of TC intensities and impacts and enable coastal populations to better respond to increasing rapid intensification threats in an era of rising sea levels. PMID:28944132

  10. Rapid shelf-wide cooling response of a stratified coastal ocean to hurricanes.

    Science.gov (United States)

    Seroka, Greg; Miles, Travis; Xu, Yi; Kohut, Josh; Schofield, Oscar; Glenn, Scott

    2017-06-01

    Large uncertainty in the predicted intensity of tropical cyclones (TCs) persists compared to the steadily improving skill in the predicted TC tracks. This intensity uncertainty has its most significant implications in the coastal zone, where TC impacts to populated shorelines are greatest. Recent studies have demonstrated that rapid ahead-of-eye-center cooling of a stratified coastal ocean can have a significant impact on hurricane intensity forecasts. Using observation-validated, high-resolution ocean modeling, the stratified coastal ocean cooling processes observed in two U.S. Mid-Atlantic hurricanes were investigated: Hurricane Irene (2011)-with an inshore Mid-Atlantic Bight (MAB) track during the late summer stratified coastal ocean season-and Tropical Storm Barry (2007)-with an offshore track during early summer. For both storms, the critical ahead-of-eye-center depth-averaged force balance across the entire MAB shelf included an onshore wind stress balanced by an offshore pressure gradient. This resulted in onshore surface currents opposing offshore bottom currents that enhanced surface to bottom current shear and turbulent mixing across the thermocline, resulting in the rapid cooling of the surface layer ahead-of-eye-center. Because the same baroclinic and mixing processes occurred for two storms on opposite ends of the track and seasonal stratification envelope, the response appears robust. It will be critical to forecast these processes and their implications for a wide range of future storms using realistic 3-D coupled atmosphere-ocean models to lower the uncertainty in predictions of TC intensities and impacts and enable coastal populations to better respond to increasing rapid intensification threats in an era of rising sea levels.

  11. Impact of Hurricanes and Nor'easters on a Migrating Inlet System

    Science.gov (United States)

    Hopkins, J.; Elgar, S.; Raubenheimer, B.

    2016-12-01

    After breaching in 2007, Katama Inlet, connecting Katama Bay to the Atlantic Ocean on the south shore of Martha's Vineyard, MA, migrated 2 km until it closed in 2015. Bathymetric surveys before and after Hurricanes Irene (2011) and Sandy (2012) indicate the strong waves and currents associated with these storms caused 2 m of erosion and deposition around the inlet mouth. The waves, currents, and bathymetric change observed during the hurricanes were used to validate the hydrodynamic and morphodynamic components of a Delft3D numerical model of the Martha's Vineyard coastline for storm (> 3 m wave heights) conditions. When driven with observed bathymetry and offshore waves, as well as simulated (WaveWatch3) winds and barometric pressures, the model reproduces the pattern and range of bathymetric change observed around the inlet. Model simulations of realistic (i.e., Irene and Sandy) and idealized storm conditions with a range of durations and wave conditions are used to test the relative importance of short-duration, high-intensity storms (hurricanes) and longer-duration, lower-intensity storms (nor'easters) on inlet migration. The simulations suggest that longer-duration, lower-intensity storms cause a higher range and variance in bathymetric change around the inlet than shorter-duration, higher-intensity storms. However, the simulations also suggest that the storm-induced migration of the inlet depends more on the wave direction at the peak of the storm than on the duration of the storm peak. The effect of storms on inlet migration over yearly time scales will be discussed. Funded by NSF, NOAA, ONR, and ASD(R&E).

  12. Hurricane Loss Estimation Models: Opportunities for Improving the State of the Art.

    Science.gov (United States)

    Watson, Charles C., Jr.; Johnson, Mark E.

    2004-11-01

    The results of hurricane loss models are used regularly for multibillion dollar decisions in the insurance and financial services industries. These models are proprietary, and this “black box” nature hinders analysis. The proprietary models produce a wide range of results, often producing loss costs that differ by a ratio of three to one or more. In a study for the state of North Carolina, 324 combinations of loss models were analyzed, based on a combination of nine wind models, four surface friction models, and nine damage models drawn from the published literature in insurance, engineering, and meteorology. These combinations were tested against reported losses from Hurricanes Hugo and Andrew as reported by a major insurance company, as well as storm total losses for additional storms. Annual loss costs were then computed using these 324 combinations of models for both North Carolina and Florida, and compared with publicly available proprietary model results in Florida. The wide range of resulting loss costs for open, scientifically defensible models that perform well against observed losses mirrors the wide range of loss costs computed by the proprietary models currently in use. This outcome may be discouraging for governmental and corporate decision makers relying on this data for policy and investment guidance (due to the high variability across model results), but it also provides guidance for the efforts of future investigations to improve loss models. Although hurricane loss models are true multidisciplinary efforts, involving meteorology, engineering, statistics, and actuarial sciences, the field of meteorology offers the most promising opportunities for improvement of the state of the art.

  13. Geologic record of Hurricane impacts on the New Jersey coast

    Science.gov (United States)

    Nikitina, Daria; Horton, Benjamin; Khan, Nicole; Clear, Jennifer; Shaw, Timothy; Enache, Mihaela; Frizzera, Dorina; Procopio, Nick; Potapova, Marina

    2016-04-01

    Hurricanes along the US Atlantic coast have caused significant damage and loss of human life over the last century. Recent studies suggest that intense-hurricane activity is closely related to changes of sea surface temperatures and therefore the risk of hurricane strikes may increase in the future. A clear understanding of the role of recent warming on tropical cyclone activity is limited by the shortness of the instrumental record. However, the sediment preserved beneath coastal wetlands is an archive of when hurricanes impacted the coast. We present two complimenting approaches that help to extend pre-historic record and assess frequency and intensity of hurricane landfalls along the New Jersey cost; dating overwash deposits and hurricane-induced salt-marsh erosion documented at multiple sites. The stratigraphic investigation of estuarine salt marshes in the southern New Jersey documented seven distinctive erosion events that correlate among different sites. Radiocarbon dates suggest the prehistoric events occurred in AD 558-673, AD 429-966, AD 558-673, Ad 1278-1438, AD 1526-1558 or AD 1630-1643 (Nikitina et al., 2014). Younger sequences correspond with historical land-falling hurricanes in AD 1903 and AD 1821 or AD 1788. Four events correlate well with barrier overwash deposits documented along the New Jersey coast (Donnelley et al., 2001 and 2004). The stratigraphic sequence of salt High resolution sedimentary-based reconstructions of past intense-hurricane landfalls indicate that significant variability in the frequency of intense hurricanes occurred over the last 2000 years.

  14. Wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Yeoman, J.C. Jr.

    1978-12-01

    This evaluation of wind turbines is part of a series of Technology Evaluations of possible components and subsystems of community energy systems. Wind turbines, ranging in size from 200 W to 10 MW, are discussed as candidates for prime movers in community systems. Estimates of performance characteristics and cost as a function of rated capacity and rated wind speed are presented. Data concerning material requirements, environmental effects, and operating procedures also are given and are represented empirically to aid computer simulation.

  15. Validation of sentinel-1A SAR coastal wind speeds against scanning LiDAR

    DEFF Research Database (Denmark)

    Ahsbahs, Tobias Torben; Badger, Merete; Karagali, Ioanna

    2017-01-01

    High-accuracy wind data for coastal regions is needed today, e.g., for the assessment of wind resources. Synthetic Aperture Radar (SAR) is the only satellite borne sensor that has enough resolution to resolve wind speeds closer than 10 km to shore but the Geophysical Model Functions (GMF) used...... for SAR wind retrieval are not fully validated here. Ground based scanning light detection and ranging (LiDAR) offer high horizontal resolution wind velocity measurements with high accuracy, also in the coastal zone. This study, for the first time, examines accuracies of SAR wind retrievals at 10 m height...... with respect to the distance to shore by validation against scanning LiDARs. Comparison of 15 Sentinel-1A wind retrievals using the GMF called C-band model 5.N (CMOD5.N) versus LiDARs show good agreement. It is found, when nondimenionalising with a reference point, that wind speed reductions are between 4...

  16. Glider observations and modeling of sediment transport in Hurricane Sandy

    Science.gov (United States)

    Miles, Travis; Seroka, Greg; Kohut, Josh; Schofield, Oscar; Glenn, Scott

    2015-03-01

    Regional sediment resuspension and transport are examined as Hurricane Sandy made landfall on the Mid-Atlantic Bight (MAB) in October 2012. A Teledyne-Webb Slocum glider, equipped with a Nortek Aquadopp current profiler, was deployed on the continental shelf ahead of the storm, and is used to validate sediment transport routines coupled to the Regional Ocean Modeling System (ROMS). The glider was deployed on 25 October, 5 days before Sandy made landfall in southern New Jersey (NJ) and flew along the 40 m isobath south of the Hudson Shelf Valley. We used optical and acoustic backscatter to compare with two modeled size classes along the glider track, 0.1 and 0.4 mm sand, respectively. Observations and modeling revealed full water column resuspension for both size classes for over 24 h during peak waves and currents, with transport oriented along-shelf toward the southwest. Regional model predictions showed over 3 cm of sediment eroded on the northern portion of the NJ shelf where waves and currents were the highest. As the storm passed and winds reversed from onshore to offshore on the southern portion of the domain waves and subsequently orbital velocities necessary for resuspension were reduced leading to over 3 cm of deposition across the entire shelf, just north of Delaware Bay. This study highlights the utility of gliders as a new asset in support of the development and verification of regional sediment resuspension and transport models, particularly during large tropical and extratropical cyclones when in situ data sets are not readily available.

  17. Wind Energy

    Energy Technology Data Exchange (ETDEWEB)

    Ganley, Jason; Zhang, Jie; Hodge, Bri-Mathias

    2016-03-15

    Wind energy is a variable and uncertain renewable resource that has long been used to produce mechanical work, and has developed into a large producer of global electricity needs. As renewable sources of energy and feedstocks become more important globally to produce sustainable products, many different processes have started adopting wind power as an energy source. Many times this is through a conversion to hydrogen through electrolysis that allows for a more continuous process input. Other important pathways include methanol and ammonia. As the demand for sustainable products and production pathways increases, and wind power capital costs decrease, the role of wind power in chemical and energy production seems poised to increase significantly.

  18. On the validity of representing hurricanes as Carnot heat engine

    Directory of Open Access Journals (Sweden)

    A. M. Makarieva

    2008-09-01

    Full Text Available It is argued, on the basis of detailed critique of published literature, that the existing thermodynamic theory of hurricanes, where it is assumed that the hurricane power is formed due to heat input from the ocean, is not physically consistent, as it comes in conflict with the first and second laws of thermodynamics. A quantitative perspective of describing hurricane energetics as that of an adiabatic atmospheric process occurring at the expense of condensation of water vapor that creates drop of local air pressure, is outlined.

  19. Uncovering wind turbine properties through two-dimensional stochastic modeling of wind dynamics.

    Science.gov (United States)

    Raischel, Frank; Scholz, Teresa; Lopes, Vitor V; Lind, Pedro G

    2013-10-01

    Using a method for stochastic data analysis borrowed from statistical physics, we analyze synthetic data from a Markov chain model that reproduces measurements of wind speed and power production in a wind park in Portugal. We show that our analysis retrieves indeed the power performance curve, which yields the relationship between wind speed and power production, and we discuss how this procedure can be extended for extracting unknown functional relationships between pairs of physical variables in general. We also show how specific features, such as the rated speed of the wind turbine or the descriptive wind speed statistics, can be related to the equations describing the evolution of power production and wind speed at single wind turbines.

  20. Hurricane Relief Operations in the Caribbean: Is the Use of the Military in Hurricane Relief Operations

    Science.gov (United States)

    2007-11-02

    Caribbean hurricanes are a type of tropical cyclone . They originate in the Atlantic Ocean off the coast of Africa and affect the Caribbean and 2 the...that will prove to be more suitable in disaster relief situations. Matthew Yarrow also shares Dynes’ view. He believes that soldiers are ill-suited... Haiti operations, in part due to the battalion commander’s lack of authority over troops from different countries. However, the performance of the