Understanding The Influence Of Assimilating Satellite Derived Observations On Mesoscale Analyses And Forecasts Of Tropical Cyclone Track And Structure
DOWNLOAD
Download Understanding The Influence Of Assimilating Satellite Derived Observations On Mesoscale Analyses And Forecasts Of Tropical Cyclone Track And Structure PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get Understanding The Influence Of Assimilating Satellite Derived Observations On Mesoscale Analyses And Forecasts Of Tropical Cyclone Track And Structure book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages. If the content not found or just blank you must refresh this page
Understanding The Influence Of Assimilating Satellite Derived Observations On Mesoscale Analyses And Forecasts Of Tropical Cyclone Track And Structure
DOWNLOAD
Author : Ting-Chi Wu
language : en
Publisher:
Release Date : 2014
Understanding The Influence Of Assimilating Satellite Derived Observations On Mesoscale Analyses And Forecasts Of Tropical Cyclone Track And Structure written by Ting-Chi Wu and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2014 with categories.
This dissertation research explores the influence of assimilating satellite-derived observations on mesoscale numerical analyses and forecasts of tropical cyclones (TC). The ultimate goal is to provide more accurate mesoscale analyses of TC and its surrounding environment for superior TC track and intensity forecasts. High spatial and temporal resolution satellite-derived observations are prepared for two TC cases, Typhoon Sinlaku and Hurricane Ike (both 2008). The Advanced Research version of the Weather and Research Forecasting Model (ARW-WRF) is employed and data is assimilated using the Ensemble Adjustment Kalman Filter (EAKF) implemented in the Data Assimilation Research Testbed. In the first part of this research, the influence of assimilating enhanced atmospheric motion vectors (AMVs) derived from geostationary satellites is examined by comparing three parallel WRF/EnKF experiments. The control experiment assimilates the same AMV dataset assimilated in NCEP operational analysis along with conventional observations from radiosondes, aircraft, and advisory TC position data. During Sinlaku and Ike, the Cooperative Institute for Meteorological Satellite Studies (CIMSS) generates hourly AMVs along with Rapid-Scan (RS) AMVs when the satellite RS mode is activated. With an order of magnitude more AMV data assimilated, the assimilation of hourly CIMSS AMV dataset exhibit superior initial TC position, intensity and structure estimates to the control analyses and the subsequent short-range forecasts. When RS AMVs are processed and assimilated, the addition of RS AMVs offers additional modification to the TC and its environment and leads to Sinlaku's recurvature toward Japan, albeit prematurely. The results demonstrate the promise of assimilating enhanced AMV data into regional TC models. The second part of this research continues the work in the first part and further explores the influence of assimilating enhanced AMV datasets by conducting parallel data-denial WRF/EnKF experiments that assimilate AMVs subsetted horizontally by their distances to the TC center (interior and exterior) and vertically by their assigned heights (upper, middle, and lower layers). For both Sinlaku and Ike, it is found: 1) interior AMVs are important for accurate TC intensity, 2) excluding upper-layer AMVs generally results in larger track errors and ensemble spread, 3) exclusion of interior AMVs has the largest impact on the forecast of TC size than exclusively removing AMVs in particular tropospheric layers, 4) the largest ensemble spreads are found in track, intensity, and size forecasts when interior and upper-layer AMVs are not included, 5) withholding the middle-layer AMVs can improve the track forecasts. Findings from this study could influence future scenarios that involve the targeted acquisition and assimilation of high-density AMV observations in TC events. The last part of the research focuses on the assimilation of hyperspectral temperature and moisture soundings and microwave based vertically-integrated total precipitable water (TPW) products derived from polar-orbiting satellites. A comparison is made between the assimilation of soundings retrieved from the combined use of Advanced Microwave Scanning Radiometer and Atmospheric Infrared Sounder (AMSU-AIRS) and sounding products provided by CIMSS (CIMSS-AIRS). AMSU-AIRS soundings provide broad spatial coverage albeit coarse resolution, whilst CIMSS-AIRS is geared towards mesoscale applications and thus provide higher spatial resolution but restricted coverage due to the use of radiance in clear sky. The assimilation of bias-corrected CIMSS-AIRS soundings provides slightly more accurate TC structure than the control case. The assimilation of AMSU-AIRS improves the track forecasts but produces weaker and smaller storm. Preliminary results of assimilating TPW product derived from the Advanced Microwave Scanning Radiometer-EOS indicate improved TC structure over the control case. However, the short-range forecasts exhibit the largest TC track errors. In all, this study demonstrates the influence of assimilating high-resolution satellite data on mesoscale analyses and forecasts of TC track and structure. The results suggest the inclusion and assimilation of observations with high temporal resolution, broad spatial coverage, and greater proximity to TCs does indeed improve TC track and structure forecasts. Such findings are beneficial for future decisions on data collecting and retrievals that are essential for TC forecasts.
Improving The Analysis And Forecast Of Tropical Mesoscale Convective Systems Through Advancing The Ensemble Data Assimilation Of Geostationary Satellite Infrared Radiance Observations
DOWNLOAD
Author : Man Yau Chan
language : en
Publisher:
Release Date : 2022
Improving The Analysis And Forecast Of Tropical Mesoscale Convective Systems Through Advancing The Ensemble Data Assimilation Of Geostationary Satellite Infrared Radiance Observations written by Man Yau Chan and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2022 with categories.
The advent of modern geostationary satellite infrared (IR) imagery has ushered in a new era in atmospheric observations. In recent years, tremendous progress has been made towards improving the forecasts of tropical cyclones and mid-latitude weather by the ensemble data assimilation (DA) of these IR observations. However, there is comparatively little work on assimilating these observations to improve the analysis and forecast of tropcial mesoscale convective systems (MCSs). Because these systems are the primary source of rainfall over the Tropics and influence global weather and climate, it is essential to accurately predict these systems. As such, the ultimate goal of my dissertation research is to improve the analysis and forecast of tropical MCSs through assimilating geostationary infrared radiance (GeoIR) observations.\\ My dissertation research has two aspects: 1) demonstrating the impacts of GeoIR ensemble DA on the analysis and forecast of tropical MCSs, and 2) devising a new computationally efficient ensemble DA algorithm to better exploit GeoIR observations. To demonstrate aspect 1, I start with assimilating real GeoIR water vapor channel brightness temperature (WV-BT) observations from the Himawari-8 geostationary satellite in a tropical squall line case over the Sumatra-Malaysia-Borneo region. The ensemble DA is executed through the state-of-the-art Pennsylvania State University Ensemble Kalman Filter (PSU-EnKF) system. Relative to a control experiment where only in-situ and satellite-derived atmospheric motion vectors (AMVs) are assimilated, the inclusion of WV-BT observations has been found to improve the analysis and forecast of the tropical squall line. Specifically, the analyses' squall line outflow positions and the analysis and forecast of the squall line's clouds were improved. These improvements scale with the frequency of GeoIR DA.\\ Since no MCS-resolving tropical reanalysis product currently exist over the Maritime Continent and GeoIR DA has demonstrated positive impacts in my tropical squall case, I have created a high-resolution tropical MCS reanalysis (TMeCSR). This is done by combining an ensemble of MCS-resolving model runs (9-km horizontal grid spacing), in-situ observations, AMV observations and WV-BT observations through the PSU-EnKF. To further enhance the TMeCSR, I have also introduced large-scale information from the European Center for Medium-Range Weather Forecasts (ECMWF) Reanalysis version 5 (ERA5). The TMeCSR is available during June, July and August of 2017, and spans a region covering most of the tropical Indian Ocean, most of continental Asia, the Maritime Continent, and the West Pacific. \\ Comparisons of TMeCSR and ERA5 against independent satellite retrievals indicate that TMeCSR's cloud and multiscale rain fields are better than those of ERA5. Furthermore, TMeCSR better captures the diurnal variability of rainfall and the statistical characteristics of MCSs. Forecasts that are initialized from TMeCSR also have more accurate rain and clouds than those that are initialized from ERA5. The TMeCSR and ERA5 forecasts have similar performances with respect to sounding and surface observations. These results indicate that TMeCSR is a promising MCS-resolving dataset for tropical MCS studies.\\ The second aspect of my dissertation research is to create a new computationally efficient ensemble DA algorithm: the bi-Gaussian ensemble Kalman filter (BGEnKF). The BGEnKF is motivated by the differences in the atmospheric dynamics, and thus the statistics, of clear atmospheric columns and cloudy atmospheric columns. Unlike the EnKF, which does not distinguish the differences between these two types of columns, the BGEnKF explicitly treats clear atmospheric columns separately from cloudy atmospheric columns. Furthermore, unlike earlier formulations in the literature\footnote{Note that the BGEnKF is a two-kernel form of Gaussian mixture model EnKFs (GMM-EnKFs). As such, the ``earlier formulations'' reference here are really earlier formulations of GMM-EnKFs.}, my formulation is computationally efficient and does not require laborous derivations and programming concerning stochastic subspaces.\\ To examine the advantages of my BGEnKF over the EnKF, I have implemented the BGEnKF into the PSU-EnKF system and have performed observing systems simulation experiments (OSSEs) using a case of tropical convection over the equatorial Indian Ocean. This case occurred during the onset of the October 2011 Madden-Julian Oscillation event. Only synthetic infrared window channel brightness temperatures (Window-BT) from the Meteorological Satellite 7 are assimilated. My results indicate that the BGEnKF outperforms the EnKF in this semi-idealized setting. These performance advantages are found in the horizontal wind vector components, temperature, specific humidity and WV-BT fields. \\ My OSSE tests with the BGEnKF are among the first to test a Gaussian mixture model EnKF (GMM-EnKF) with a realistic weather model. The encouraging results motivate further testing and development of the BGEnKF algorithm. If the BGEnKF consistently outperforms the EnKF at assimilating GeoIR observations, the BGEnKF will replace the EnKF in operational weather forecasting systems in the future.
Parameterization Schemes
DOWNLOAD
Author : David J. Stensrud
language : en
Publisher: Cambridge University Press
Release Date : 2007-05-03
Parameterization Schemes written by David J. Stensrud and has been published by Cambridge University Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2007-05-03 with Science categories.
Contents: 1.
Advanced Numerical Modeling And Data Assimilation Techniques For Tropical Cyclone Predictions
DOWNLOAD
Author : U.C. Mohanty
language : en
Publisher: Springer
Release Date : 2016-11-21
Advanced Numerical Modeling And Data Assimilation Techniques For Tropical Cyclone Predictions written by U.C. Mohanty and has been published by Springer this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016-11-21 with Science categories.
This book deals primarily with monitoring, prediction and understanding of Tropical Cyclones (TCs). It was envisioned to serve as a teaching and reference resource at universities and academic institutions for researchers and post-graduate students. It has been designed to provide a broad outlook on recent advances in observations, assimilation and modeling of TCs with detailed and advanced information on genesis, intensification, movement and storm surge prediction. Specifically, it focuses on (i) state-of-the-art observations for advancing TC research, (ii) advances in numerical weather prediction for TCs, (iii) advanced assimilation and vortex initialization techniques, (iv) ocean coupling, (v) current capabilities to predict TCs, and (vi) advanced research in physical and dynamical processes in TCs. The chapters in the book are authored by leading international experts from academic, research and operational environments. The book is also expected to stimulate critical thinking for cyclone forecasters and researchers, managers, policy makers, and graduate and post-graduate students to carry out future research in the field of TCs.
Observation Theory And Modeling Of Atmospheric Variability
DOWNLOAD
Author : Xun Zhu
language : en
Publisher: World Scientific
Release Date : 2004
Observation Theory And Modeling Of Atmospheric Variability written by Xun Zhu and has been published by World Scientific this book supported file pdf, txt, epub, kindle and other format this book has been release on 2004 with Science categories.
This book contains tutorial and review articles as well as specific research letters that cover a wide range of topics: (1) dynamics of atmospheric variability from both basic theory and data analysis, (2) physical and mathematical problems in climate modeling and numerical weather prediction, (3) theories of atmospheric radiative transfer and their applications in satellite remote sensing, and (4) mathematical and statistical methods. The book can be used by undergraduates or graduate students majoring in atmospheric sciences, as an introduction to various research areas; and by researchers and educators, as a general review or quick reference in their fields of interest.
Hurricane Monitoring With Spaceborne Synthetic Aperture Radar
DOWNLOAD
Author : Xiaofeng Li
language : en
Publisher: Springer
Release Date : 2017-05-17
Hurricane Monitoring With Spaceborne Synthetic Aperture Radar written by Xiaofeng Li and has been published by Springer this book supported file pdf, txt, epub, kindle and other format this book has been release on 2017-05-17 with Nature categories.
This book discusses in detail the science and morphology of powerful hurricane detection systems. It broadly addresses new approaches to monitoring hazards using freely available images from the European Space Agency’s (ESA’s) Sentinel-1 SAR satellite and benchmarks a new interdisciplinary field at the interface between oceanography, meteorology and remote sensing. Following the launch of the first European Space Agency (ESA) operational synthetic aperture radar satellite, Sentinel-1, in 2014, synthetic aperture radar (SAR) data has been freely available on the Internet hub in real-time. This advance allows weather forecasters to view hurricanes in fine detail for the first time. As a result, the number of synthetic aperture radar research scientists working in this field is set to grow exponentially in the next decade; the book is a valuable resource for this large and budding audience.
The Global Monsoon System
DOWNLOAD
Author : Chih-Pei Chang
language : en
Publisher: World Scientific
Release Date : 2011
The Global Monsoon System written by Chih-Pei Chang and has been published by World Scientific this book supported file pdf, txt, epub, kindle and other format this book has been release on 2011 with Science categories.
This book presents a current review of the science of monsoon research and forecasting. The contents are based on the invited reviews presented at the World Meteorological Organization's Fourth International Workshop on Monsoons in late 2008, with subsequent manuscripts revised from 2009 to early 2010. The book builds on the concept that the monsoons in various parts of the globe can be viewed as components of an integrated global monsoon system, while emphasizing that significant region-specific characteristics are present in individual monsoon regions. The topics covered include all major monsoon regions and time scales (mesoscale, synoptic, intraseasonal, interannual, decadal, and climate change). It is intended to provide an updated comprehensive review of the current status of knowledge, modeling capability, and future directions in the research of monsoon systems around the world.
International Aerospace Abstracts
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 1996
International Aerospace Abstracts written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1996 with Aeronautics categories.
Monthly Weather Review
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2007
Monthly Weather Review written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2007 with Meteorology categories.
Physics Briefs
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 1994
Physics Briefs written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1994 with Physics categories.