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Tropical cyclones

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Full-Text Articles in Meteorology

Influence Of Tropical Cyclones, Southwest Monsoon, And Tropical Cyclone-Enhanced Southwest Monsoon On Rainfall Variability Over The Western Coast Of The Philippines, Alwin Bathan, Lyndon Mark Olaguera, Faye Abigail T. Cruz, Jose Ramon T. Villarin, Joel T. Maquiling, Maria Obiminda L. Cambaliza, John A. Manalo, Jun Matsumoto Jun 2025

Influence Of Tropical Cyclones, Southwest Monsoon, And Tropical Cyclone-Enhanced Southwest Monsoon On Rainfall Variability Over The Western Coast Of The Philippines, Alwin Bathan, Lyndon Mark Olaguera, Faye Abigail T. Cruz, Jose Ramon T. Villarin, Joel T. Maquiling, Maria Obiminda L. Cambaliza, John A. Manalo, Jun Matsumoto

SOSE Affiliate: Manila Observatory

This study investigates the processes driving interannual variability of rainfall over the western coast of the Philippines during the peak southwest monsoon (SWM) months (July–September) from 1961 to 2022. Specifically, it describes how tropical cyclones (TC), SWM, and TC-enhanced SWM influence SWM rainfall variability. Rainfall measurements from 11 stations along the western coast of the Philippines were classified into three types: direct TC rainfall (PD), indirect TC rainfall (PI), and SWM rainfall (PSM). The yearly contributions of PD, PI, and PSM to SWM rainfall were estimated to be 15.4 %, 33.1 %, and 51.5 %, respectively. Furthermore, four rainfall variability …


Investigating The Role Of Aerosols In Extreme Precipitation Events Along The Gulf Coast Of The U.S.A., Wenjia Cao May 2025

Investigating The Role Of Aerosols In Extreme Precipitation Events Along The Gulf Coast Of The U.S.A., Wenjia Cao

LSU Doctoral Dissertations

Atmospheric aerosols have been found to influence tropical cyclone (TC) and flood event development. In this study, the Weather Research and Forecasting model is applied to investigate specific microphysical impacts and aerosol sensitivity to heavy precipitation and TC events in the U.S. Gulf Coastal area. The Thompson aerosol-aware scheme with regular and adjusted aerosol concentration scenarios is used to quantify precipitation, wind field, horizontal/vertical structures, and track variations, by aerosol mixing ratio. In general, results for the three storms analyzed (the 2016 Baton Rouge, Louisiana, flood event (Chapter 2); Hurricane Harvey in 2017 (Chapter 3); and an idealized storm event …


An Investigation Of Geostationary Satellite Imagery To Compare Developing And Non-Developing African Easterly Waves, Jenna Bartlett Aug 2022

An Investigation Of Geostationary Satellite Imagery To Compare Developing And Non-Developing African Easterly Waves, Jenna Bartlett

Theses and Dissertations

African easterly waves (AEWs) are known precursors to tropical cyclone (TC) formation, although it is not always clear which AEWs will develop and which AEWs will not. To investigate AEW evolution, this study examines novel observations from the geostationary Advanced Baseline Imager (ABI) during July-September 2019. Case studies are conducted for two AEWs: one that became Hurricane Dorian, the strongest and most devastating hurricane of the 2019 Atlantic hurricane season, and a long-lived September AEW that did not become a TC. Lower-level moisture and flow, and the strength and spatial distribution of convective activity, differed between these two waves. By …


The Impact Of Sea-Level Rise In Numerically Modeled Landfalling Hurricanes: Katrina And The Gulf Coast., Serenity Nadirah Mercuri May 2022

The Impact Of Sea-Level Rise In Numerically Modeled Landfalling Hurricanes: Katrina And The Gulf Coast., Serenity Nadirah Mercuri

Electronic Theses and Dissertations

With climate change, landfalling hurricanes become an increasing threat to coastal regions. However, the interactions between the coastal landscape and landfalling hurricanes are often overlooked when addressing sea-level rise outside of inundation and independent of sea surface temperature. This study analyzed the potential impacts regarding structure and intensity as a result of sea-level rise in the Gulf of Mexico using the WRF-ARW numerical model coupled with a 1D ocean model. Analysis showed that 10 m windspeed from landfall forward was higher in modified coastlines, and minimum sea-level pressure post-landfall was consistently lower for modified runs where storms maintain a higher …


Climatology, Variability, And Return Periods Of Tropical Cyclone Strikes In The Northeastern And Central Pacific Basins, Nicholas S. Grondin Mar 2019

Climatology, Variability, And Return Periods Of Tropical Cyclone Strikes In The Northeastern And Central Pacific Basins, Nicholas S. Grondin

LSU Master's Theses

Tropical cyclones (TCs) are among the most destructive meteorological phenomena and impact the lives of people who reside along the coast. The American Pacific Coastline borders the second most active TC development region in the world, the northeastern Pacific (NE Pac) basin. This region, along with the Central Pacific (C Pac)-bordering Hawaii is home to a growing population and cities engaged in a variety of economic activities, most prominently agriculture, fishing, and tourism. This study analyzes fifty-two (1966-2017) years of NE Pac and C Pac TCs through applying track data from the National Hurricane Center’s HURDAT2 and a TC size …


A Revised Technique For Measuring Vertical Velocity Using Dropsondes, Timothy Connor Nelson Jan 2019

A Revised Technique For Measuring Vertical Velocity Using Dropsondes, Timothy Connor Nelson

Legacy Theses & Dissertations (2009 - 2024)

The earliest iterations of dropsondes in the 1960's obtained vertical velocity by measuring the geometric fall speed of the dropsonde and the true airspeed (TAS) of the dropsonde from a pitot-static. The vertical velocity errors from this methodology were claimed to be ±1 m s-1. Subsequent dropsonde iterations used various forms of the drag force equation to obtain vertical velocity. The accuracy of these drag force-based measurements, however, are also quite large at ±1–2 m s-1. In this dissertation, an attempt is made to improve vertical velocity errors by revisiting and revising the pitot-static-derived TAS methodology on the eXpendable Digital …


Methodology To Analyze Tropical Cyclone Intensity From Microwave Imagery, Matthew W. Perkins Mar 2018

Methodology To Analyze Tropical Cyclone Intensity From Microwave Imagery, Matthew W. Perkins

Theses and Dissertations

Satellites with microwave remote sensing capabilities can be utilized to study atmospheric phenomena through high-level cloud cover (particularly cirrus), an advantage over visible and infrared bands, which only sense cloud tops. This unique capability makes microwave imagery ideal for studying the cloud structures of tropical cyclones (TCs) in detail, and relating these features to TC intensity. Techniques to estimate the intensity of TCs using infrared imagery, such as the Dvorak technique, have been used in TC forecasting for 40 years. However, due to the inherent temporal limitations of microwave imagery, no such similar technique exists for the microwave spectrum. This …


Reconstructing Historical Hurricane Tracks In The Atlantic Basin: Three Case Studies From The 1840s, Emily L. Cerrito Mar 2018

Reconstructing Historical Hurricane Tracks In The Atlantic Basin: Three Case Studies From The 1840s, Emily L. Cerrito

USF Tampa Graduate Theses and Dissertations

Analyzing past tropical cyclone activity enables researchers to recognize patterns of hurricane variability, estimate hurricane return periods, and assess local risk to future storms. This paleotempestology study used original primary data to make the historical record as comprehensive and accurate as possible for three major hurricanes: October 1844, October 1846, and September 1848. This thesis presents the reconstructed storm tracks, assesses the societal impacts, and evaluates the storm intensity of these three major hurricanes for the eastern U.S. and Cuba. The data utilized in this study include ship logbooks, newspapers, diaries, and instrumental meteorological records. A geographic information system (GIS) …


The Extratropical Transition Of Tropical Cyclones. Part I: Cyclonic Evolution And Direct Impacts, Clark Evans, Kimberly M. Wood, Sim D. Aberson, Heather M. Archambault, Shawn M. Milrad, Lance F. Bosart, Et Al. Nov 2017

The Extratropical Transition Of Tropical Cyclones. Part I: Cyclonic Evolution And Direct Impacts, Clark Evans, Kimberly M. Wood, Sim D. Aberson, Heather M. Archambault, Shawn M. Milrad, Lance F. Bosart, Et Al.

Publications

Extratropical transition (ET) is the process by which a tropical cyclone, upon encountering a baroclinic environment and reduced sea surface temperature at higher latitudes, transforms into an extratropical cyclone. This process is influenced by, and influences, phenomena from the tropics to the midlatitudes and from the meso- to the planetary scales to extents that vary between individual events. Motivated in part by recent high-impact and/or extensively observed events such as North Atlantic Hurricane Sandy in 2012 and western North Pacific Typhoon Sinlaku in 2008, this review details advances in understanding and predicting ET since the publication of an earlier review …


Tropical Cyclone Intensification Under Moderate Vertical Wind Shear, Rosimar Rios-Berrios Jan 2017

Tropical Cyclone Intensification Under Moderate Vertical Wind Shear, Rosimar Rios-Berrios

Legacy Theses & Dissertations (2009 - 2024)

Deep-layer (200–850 hPa) vertical wind shear is generally an inhibiting factor for tropical cyclone intensification. Multiple studies—ranging from case studies to climatological analyses—have consistently shown that the chances of tropical cyclone intensification decrease with increasing vertical wind shear magnitude. However, tropical cyclones can intensify under moderate shear—the range of shear magnitudes that are neither too weak to have negligible influence on intensity nor too strong to completely halt intensification. Intensity, track, and precipitation forecasts of tropical cyclones under moderate shear can be highly uncertain; therefore, explaining how tropical cyclones evolve under seemingly unfavorable conditions is an important step towards improved …


Modeling The Impact Of Land Surface Feedbacks On Post Landfall Tropical Cyclones, Subashini Subramanian Dec 2016

Modeling The Impact Of Land Surface Feedbacks On Post Landfall Tropical Cyclones, Subashini Subramanian

Open Access Dissertations

The land surface is an important component of numerical models. The land surface models are modules that control energy partitioning, compute surface exchange coefficients and form the only physical boundary in a regional scale numerical model. Thus, an accurate representation of land surface is critical to compute surface fluxes, represent the boundary layer evolution and affect changes in weather systems. Land surface can affect landfalling tropical cyclones in two ways: (i) when the cyclone is offshore and land can influence cyclones by introducing dry (or moist) air that can weaken (or strengthen) the organized convective structure of cyclones, and (ii) …


New Metric For Defining The Time Of Extratropical Transition Of Tropical Cyclones, Ajay Raghavendra, Shawn M. Milrad Jan 2016

New Metric For Defining The Time Of Extratropical Transition Of Tropical Cyclones, Ajay Raghavendra, Shawn M. Milrad

Publications

Almost half of all tropical cyclones (TCs) in the Atlantic basin undergo extratropical transition (ET). During an ET event, wind fields often expand dramatically, resulting in more widely-felt impacts. Moreover, the heaviest precipitation typically shifts to the left-of-center (LOC), which can result in inland flash flooding hundreds of kilometers from the cyclone center. While several objective metrics to track and predict ET have been developed, they rely at least partially on internal tropical cyclone structure, for which numerical models show less skill. Further, these metrics fail to account for static stability, which plays a vital role in determining precipitation amounts. …


Hurricanes And Climate The U.S. Clivar Working Group On Hurricanes, Kevin J.E. Walsh, Suzana J. Camargo, Gabriel A. Vecchi, Anne Sophie Daloz, James Elsner, Kerry Emanuel, Michael Horn, Young-Kwon Lim, Malcom Roberts, Christina Patricola, Enrico Scoccimarro, Adam H. Sobel, Sarah Strazzo, Gabrielle Villarini, Michael Wehner, Ming Zhao, James P. Kossin, Tim Larow, Kazuyoshi Oouchi, Sigfried Schubert, Hui Wang, Julio Bacmeister, Ping Chang, Fabrice Chauvin, Christiane Jablonowski, Arun Kumar, Hiroyuki Murakami, Tomoaki Ose, Kevin A. Reed, Ramalingam Saravanan, Yohei Yamada, Colin M. Zarzycki, Pier Luigi Vidale, Jefferey A. Jonas, Naomi Henderson Jun 2015

Hurricanes And Climate The U.S. Clivar Working Group On Hurricanes, Kevin J.E. Walsh, Suzana J. Camargo, Gabriel A. Vecchi, Anne Sophie Daloz, James Elsner, Kerry Emanuel, Michael Horn, Young-Kwon Lim, Malcom Roberts, Christina Patricola, Enrico Scoccimarro, Adam H. Sobel, Sarah Strazzo, Gabrielle Villarini, Michael Wehner, Ming Zhao, James P. Kossin, Tim Larow, Kazuyoshi Oouchi, Sigfried Schubert, Hui Wang, Julio Bacmeister, Ping Chang, Fabrice Chauvin, Christiane Jablonowski, Arun Kumar, Hiroyuki Murakami, Tomoaki Ose, Kevin A. Reed, Ramalingam Saravanan, Yohei Yamada, Colin M. Zarzycki, Pier Luigi Vidale, Jefferey A. Jonas, Naomi Henderson

Publications

While a quantitative climate theory of tropical cyclone formation remains elusive, considerable progress has been made recently in our ability to simulate tropical cyclone climatologies and to understand the relationship between climate and tropical cyclone formation. Climate models are now able to simulate a realistic rate of global tropical cyclone formation, although simulation of the Atlantic tropical cyclone climatology remains challenging unless horizontal resolutions finer than 50 km are employed. This article summarizes published research from the idealized experiments of the Hurricane Working Group of U.S. Climate and Ocean: Variability, Predictability and Change (CLIVAR). This work, combined with results from …


Evaluating Preferred Direction Tropical Cyclone Track Variability In An Operational Global Ensemble Prediction System, Travis Elless Jan 2015

Evaluating Preferred Direction Tropical Cyclone Track Variability In An Operational Global Ensemble Prediction System, Travis Elless

Legacy Theses & Dissertations (2009 - 2024)

Ensemble forecasts of Tropical Storm Debby and Hurricane Sandy (2012) highlight instances where variability in tropical cyclone (TC) position forecasts are stretched along a preferred direction. The goal of this thesis is to analyze this stretching of variability in a global ensemble prediction system, particularly the European Centre for Medium-Range Weather Forecasts (ECMWF), to determine how often and under what conditions does variability stretching occur, and ultimately what feature(s) are responsible for generating this variability.


Dynamical Downscaling Projections Of Twenty-First-Century Atlantic Hurricane Activity: Cmip3 And Cmip5 Model-Based Scenarios, Thomas R. Knutson, Joseph J. Sirutis, Gabriel A. Vecchi, Stephen Garner, Ming Zhao, Hyeong-Seog Kim, Morris Bender, Robert E. Tuleya, Isaac M. Held, Gabriele Villarini Sep 2013

Dynamical Downscaling Projections Of Twenty-First-Century Atlantic Hurricane Activity: Cmip3 And Cmip5 Model-Based Scenarios, Thomas R. Knutson, Joseph J. Sirutis, Gabriel A. Vecchi, Stephen Garner, Ming Zhao, Hyeong-Seog Kim, Morris Bender, Robert E. Tuleya, Isaac M. Held, Gabriele Villarini

CCPO Publications

Twenty-first-century projections of Atlantic climate change are downscaled to explore the robustness of potential changes in hurricane activity. Multimodel ensembles using the phase 3 of the Coupled Model Intercomparison Project (CMIP3)/Special Report on Emissions Scenarios A1B (SRES A1B; late-twenty-first century) and phase 5 of the Coupled Model Intercomparison Project (CMIP5)/representative concentration pathway 4.5 (RCP4.5; early- and late-twenty-first century) scenarios are examined. Ten individual CMIP3 models are downscaled to assess the spread of results among the CMIP3 (but not the CMIP5) models. Downscaling simulations are compared for 18-km grid regional and 50-km grid global models. Storm cases from the regional model …


Frequency, Intensity, And Sensitivity To Sea Surface Temperature Of North Atlantic Tropical Cyclones In Best-Track And Simulated Data, Sarah Strazzo, James B. Elsner, Jill C. Trepanier, Kerry A. Emanuel Aug 2013

Frequency, Intensity, And Sensitivity To Sea Surface Temperature Of North Atlantic Tropical Cyclones In Best-Track And Simulated Data, Sarah Strazzo, James B. Elsner, Jill C. Trepanier, Kerry A. Emanuel

Publications

Synthetic hurricane track data generated from a downscaling approach are compared to best-track (observed) data to analyze differences in regional frequency, intensity, and sensitivity of limiting intensity to sea surface temperature (SST). Overall, the spatial distributions of observed and simulated hurricane counts match well, although there are relatively fewer synthetic storms in the eastern quarter of the basin. Additionally, regions of intense synthetic hurricanes tend to coincide with regions of intense observed hurricanes. The sensitivity of limiting hurricane intensity to SST computed from synthetic data is slightly lower than sensitivity computed from observed data (5.561.31 m s21 (standard error, SE) …


Precipitation Modulation By The Saint Lawrence River Valley In Association With Transitioning Tropical Cyclones, Shawn M. Milrad, Eyad H. Atallah, John R. Gyakum Apr 2013

Precipitation Modulation By The Saint Lawrence River Valley In Association With Transitioning Tropical Cyclones, Shawn M. Milrad, Eyad H. Atallah, John R. Gyakum

Publications

The St. Lawrence River valley (SLRV) is an important orographic feature in eastern Canada that can affect surface wind patterns and contribute to locally higher amounts of precipitation. The impact of the SLRV on precipitation distributions associated with transitioning, or transitioned, tropical cyclones that approached the region is assessed. Such cases can result in heavy precipitation during the warm season, as during the transition of Hurricane Ike (2008). Thirty-eight tropical cyclones tracked within 500 km of the SLRV from 1979 to 2011. Utilizing the National Centers for Environmental Prediction (NCEP) North American Regional Reanalysis (NARR), 19 of the 38 cases …


An Analysis Of The Formation And Evolution Of The 1989 Western North Pacific Subtropical Gyre, Brian Andrew Crandall Jan 2012

An Analysis Of The Formation And Evolution Of The 1989 Western North Pacific Subtropical Gyre, Brian Andrew Crandall

Legacy Theses & Dissertations (2009 - 2024)

This thesis conducts an observational study of a large cyclonic gyre that developed in the Western North Pacific (WNP) in late July 1989. For a period of six days, azimuthally-averaged winds at 850 hPa remained cyclonic out from the center of circulation to the 2000 km radius, with azimuthally-averaged tangential wind speeds at or greater than 10 m s-1. The gyre exhibited an asymmetric convection pattern, with the center, north and west flanks devoid of large convective areas, but the southern and eastern flanks maintained large-scale convective regions, extending as much as 4000 km in longitude.


Convectively-Coupled Kelvin Waves Over The Tropical Atlantic And African Regions And Their Influence On Atlantic Tropical Cyclogenesis, Michael John Ventrice Jan 2012

Convectively-Coupled Kelvin Waves Over The Tropical Atlantic And African Regions And Their Influence On Atlantic Tropical Cyclogenesis, Michael John Ventrice

Legacy Theses & Dissertations (2009 - 2024)

High-amplitude convectively coupled atmospheric Kelvin waves (CCKWs) are explored over the tropical Atlantic during the boreal summer. Atlantic tropical cyclogenesis is found to be more frequent during the passage of the convectively active phase of the CCKW, and most frequent two days after its passage. CCKWs impact convection within the mean latitude of the inter-tropical convergence zone over the northern tropical Atlantic. In addition to convection, CCKWs also impact the large scale environment that favors Atlantic tropical cyclogenesis (i.e., deep vertical wind shear, moisture, and low-level relative vorticity).


Dynamical And Precipitation Structures Of Poleward-Moving Tropical Cyclones In Eastern Canada, 1979-2005, Shawn M. Milrad, Eyad H. Atallah, John R. Gyakum Mar 2009

Dynamical And Precipitation Structures Of Poleward-Moving Tropical Cyclones In Eastern Canada, 1979-2005, Shawn M. Milrad, Eyad H. Atallah, John R. Gyakum

Publications

Tropical cyclones in the western North Atlantic basin are a persistent threat to human interests along the east coast of North America. Occurring mainly during the late summer and early autumn, these storms often cause strong winds and extreme rainfall and can have a large impact on the weather of eastern Canada. From 1979 to 2005, 40 named (by the National Hurricane Center) tropical cyclones tracked over eastern Canada. Based on the time tendency of the low-level (850–700 hPa) vorticity, the storms are partitioned into two groups: ‘‘intensifying’’ and ‘‘decaying.’’ The 16 intensifying and 12 decaying cases are then analyzed …


Cirene Air-Sea Interactions In The Seychelles-Chagos Thermocline Ridge Region, J. Vialard, J. P. Duvel, M. J. Mcphaden, P. Bouruet-Aubertot, B. Ward, E. Key, D. Bourras, R. Weller, P. Minnett, A. Weil Jan 2009

Cirene Air-Sea Interactions In The Seychelles-Chagos Thermocline Ridge Region, J. Vialard, J. P. Duvel, M. J. Mcphaden, P. Bouruet-Aubertot, B. Ward, E. Key, D. Bourras, R. Weller, P. Minnett, A. Weil

OES Faculty Publications

A field experiment in the southwestern Indian Ocean provides new insights into ocean-atmosphere interactions in a key climatic region.


Numerical Simulations Of The Impacts Of The Saharan Air Layer On Atlantic Tropical Cyclone Development, Donglian Sun, K. M. Lau, Menas Kafatos, Z. Boybeyi, G. Leptoukh, C. Yang, Ruixin Yang Jan 2009

Numerical Simulations Of The Impacts Of The Saharan Air Layer On Atlantic Tropical Cyclone Development, Donglian Sun, K. M. Lau, Menas Kafatos, Z. Boybeyi, G. Leptoukh, C. Yang, Ruixin Yang

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this study, the role of the Saharan air layer (SAL) is investigated in the development and intensification of tropical cyclones (TCs) via modifying environmental stability and moisture, using multisensor satellite data, long-term TC track and intensity records, dust data, and numerical simulations with a state-of-the-art Weather Research and Forecasting model (WRF). The long-term relationship between dust and Atlantic TC activity shows that dust aerosols are negatively associated with hurricane activity in the Atlantic basin, especially with the major hurricanes in the western Atlantic region. Numerical simulations with the WRF for specific cases during the NASA African Monsoon Multidisciplinary Analyses …