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23
2008: Changes in Tropical Cyclone Activity due to Global Warming: Results from a High-Resolution Coupled General Circulation Model
- J. of Clim
"... This study investigates the possible changes that the greenhouse global warming might generate in the characteristics of the tropical cyclones (TCs). The analysis has been performed using scenario climate simulations carried out with a fully coupled high-resolution global general circulation model. ..."
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This study investigates the possible changes that the greenhouse global warming might generate in the characteristics of the tropical cyclones (TCs). The analysis has been performed using scenario climate simulations carried out with a fully coupled high-resolution global general circulation model. The capability of the model to reproduce a reasonably realistic TC climatology has been assessed by comparing the model results from a simulation of the 20th Century with observations. The model appears to be able to simulate tropical cyclone-like vortices with many features similar to the observed TCs. The simulated TC activity exhibits realistic geographical distribution, seasonal modulation and interannual variability, suggesting that the model is able to reproduce the major basic mechanisms that link the TC occurrence with the large scale circulation. The results from the climate scenarios reveal a substantial general reduction of the TC frequency when the atmospheric CO2 concentration is doubled and quadrupled. The reduction appears particularly evident for the tropical North West Pacific (NWP) and North Atlantic (ATL). In the NWP the weaker TC activity seems to be associated with a reduced amount of convective instabilities. In the ATL region the weaker TC activity seems to be due to both the increased
Simulation of interannual variability of tropical storm frequency in an ensemble of GCM integrations
- J. Climate
, 1997
"... The present study examines the simulation of the number of tropical storms produced in GCM integrations with a prescribed SST. A 9-member ensemble of 10-yr integrations (1979–88) of a T42 atmospheric model forced by observed SSTs has been produced; each ensemble member differs only in the initial at ..."
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Cited by 32 (5 self)
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The present study examines the simulation of the number of tropical storms produced in GCM integrations with a prescribed SST. A 9-member ensemble of 10-yr integrations (1979–88) of a T42 atmospheric model forced by observed SSTs has been produced; each ensemble member differs only in the initial atmospheric conditions. An objective procedure for tracking-model-generated tropical storms is applied to this ensemble during the last 9 yr of the integrations (1980–88). The seasonal and monthly variations of tropical storm numbers are compared with observations for each ocean basin. Statistical tools such as the Chi-square test, the F test, and the t test are applied to the ensemble number of tropical storms, leading to the conclusion that the potential predictability is particularly strong over the western North Pacific and the eastern North Pacific, and to a lesser extent over the western North Atlantic. A set of tools including the joint probability distribution and the ranked probability score are used to evaluate the simulation skill of this ensemble simulation. The simulation skill over the western North Atlantic basin appears to be exceptionally high, particularly during years of strong potential predictability. 1.
Q.: An example of temperature structure differences in two cyclone systems derived from the Advanced Microwave Sounder Unit, Wea
- Forecast
"... The Advanced Microwave Sounding Unit (AMSU) has better horizontal resolution and vertical temperature sounding abilities than its predecessor, the Microwave Sounding Unit (MSU). Those improved capabilities are demonstrated with observations of two cyclonic weather systems located in the South Pacifi ..."
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Cited by 10 (3 self)
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The Advanced Microwave Sounding Unit (AMSU) has better horizontal resolution and vertical temperature sounding abilities than its predecessor, the Microwave Sounding Unit (MSU). Those improved capabilities are demonstrated with observations of two cyclonic weather systems located in the South Pacific Ocean on 1 March 1999. These weather systems appear quite similar in conventional infrared satellite imagery, suggesting that they are comparable in structure and intensity. However, an analysis using temperature retrievals created from the AMSU shows that their vertical thermal structure is quite different. This is just one example of an application highlighting the improved sounding capabilities available with the AMSU instrument suite. A preliminary look at what the AMSU can provide in data-void regions and a discussion of future plans to create AMSU-based products to better diagnose synoptic-scale weather systems are presented.
Landscape analysis and pattern of Hurricane impact and circulation on mangrove forests of the Everglades.
- Wetlands
, 2009
"... Abstract: 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 stor ..."
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Abstract: 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.
Environmental and convective influence on tropical cyclone development vs. non- development
- Dept. of Atmos. Sci. Paper No. 436, Colo. State Univ., Fort Collins, CO
, 1987
"... To study the physical processes associated with early-stage tropical cyclone develop-ment vs. non-development, composite and individual case analyses were made of US Air Force northwestern Pacific 950 mb ("'1500 feet) aircraft "investigative " reconnaissance flights into tropical ..."
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Cited by 2 (0 self)
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To study the physical processes associated with early-stage tropical cyclone develop-ment vs. non-development, composite and individual case analyses were made of US Air Force northwestern Pacific 950 mb ("'1500 feet) aircraft "investigative " reconnaissance flights into tropical disturbances. Analysis of a 7-year period provided about 100 cases of development vs. 100 cases of non-development. Significantly higher radial inflow was observed in the inner-core of developing cases as compared to non-developing cases. Only minimal tangential winds and sea-level pressure differences were observed between devel-oping and non-developing cases. Many formation cases had strong "packets " of radial momentum surges to inner-core radii at selective azimuthal locations. These wind surges were related to satellite-observed concentrations of deep convection near the inner-core of the developing disturbances and appeared to be environmentally induced. Another factor influencing tropical cyclone genesis was the strength of a disturbance's upper-tropospheric (250 mb) relative wind "blowthrough " or ventilation. The direction of the 250 mb relative wind to the tropical disturbance's moving center was found to have a
1.6 FORMATION OF THE HURRICANE EYE
"... A plethora of genesis mechanisms result in tropical cyclone formation. Gray (1998b) purports that hundreds of tropical cyclogenesis theories have been put forward. Some formation mechanisms (or influences) include low ..."
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A plethora of genesis mechanisms result in tropical cyclone formation. Gray (1998b) purports that hundreds of tropical cyclogenesis theories have been put forward. Some formation mechanisms (or influences) include low
An Objective Satellite-Based Tropical Cyclone Size Climatology
, 2013
"... Storm-centered infrared (IR) imagery of tropical cyclones (TCs) is related to the 850-hPa mean tangential wind at a radius of 500km (V500) calculated from 6-hourly global numerical analyses for North Atlantic and eastern North Pacific TCs for 1995–2011. V500 estimates are scaled using the climatolog ..."
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Storm-centered infrared (IR) imagery of tropical cyclones (TCs) is related to the 850-hPa mean tangential wind at a radius of 500km (V500) calculated from 6-hourly global numerical analyses for North Atlantic and eastern North Pacific TCs for 1995–2011. V500 estimates are scaled using the climatological vortex decay rate beyond 500km to estimate the radius of 5 kt (1 kt 5 0.514m s21) winds (R5) or TC size. A much larger his-torical record of TC-centered IR imagery (1978–2011) is then used to estimate TC sizes and form a global TC size climatology. The basin-specific distributions of TC size reveal that, among other things, the eastern North Pacific TC basins have the smallest while western North Pacific have the largest TC size distributions. The life cycle of TC sizes with respect to maximum intensity shows that TC growth characteristics are different among the individual TC basins, with the North Atlantic composites showing continued growth after maximum in-tensity. Small TCs are generally located at lower latitudes, westward steering, and preferred in seasons when environmental low-level vorticity is suppressed. Large TCs are generally located at higher latitudes, poleward steering, and preferred in enhanced low-level vorticity environments. Postmaximum intensity growth of TCs occurs in regions associated with enhanced baroclinicity and TC recurvature, while those that do not grow much are associated with west movement, erratic storm tracks, and landfall at or near the time of maximum intensity. With respect to climate change, no significant long-term trends are found in the dataset of TC size. 1.
Upper Oceanic Energy Response to Tropical Cyclone Passage
, 2012
"... The upper oceanic temporal response to tropical cyclone (TC) passage is investigated using a 6-yr daily record of data-driven analyses of two measures of upper ocean energy content based on the U.S. Navy’s Coupled Ocean Data Assimilation System and TC best-track records. Composite analyses of these ..."
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The upper oceanic temporal response to tropical cyclone (TC) passage is investigated using a 6-yr daily record of data-driven analyses of two measures of upper ocean energy content based on the U.S. Navy’s Coupled Ocean Data Assimilation System and TC best-track records. Composite analyses of these data at points along theTC track are used to investigate the type,magnitude, and persistence of upper ocean response to TC passage, and to infer relationships between routinely available TC information and the upper ocean response. Upper oceanic energy decreases in these metrics are shown to persist for at least 30 days—long enough to possibly affect future TCs. Results also indicate that TC kinetic energy (KE) should be considered when assessing TC impacts on the upper ocean, and that existing TC best-track structure information, which is used here to estimate KE, is sufficient for such endeavors. Analyses also lead to recommendations concerning metrics of upper ocean energy. Finally, parameterizations for the lagged, along-track, upper ocean response to TC passage are developed. These show that the sea surface temperature (SST) is best related to the KE and the latitude whereas the upper ocean energy is a function of KE, initial upper ocean energy conditions, and translation speed. These parameterizations imply that the 10-day lagged SST cooling is approximately 0.78C for a ‘‘typical’ ’ TC at 308 latitude, whereas the same storm results in 10-day (30-day) lagged decreases of upper oceanic energy by about 12 (7) kJ cm22 and a 0.58C (0.38C) cooling of the top 100 m of ocean. 1.
et Océanique [physics.ao-ph]. Universite ́ de la Réunion, 2012. Français. <NNT: 2012LARE0014>. <tel-01131171>
, 2015
"... Intensification rapide des cyclones tropicaux du sud-ouest de l’océan Indien (SWIO) : dynamique interne et influences externes Marie-Dominique Leroux To cite this version: Marie-Dominique Leroux. Intensification rapide des cyclones tropicaux du sud-ouest de l’océan Indien (SWIO) : dynamique intern ..."
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Intensification rapide des cyclones tropicaux du sud-ouest de l’océan Indien (SWIO) : dynamique interne et influences externes Marie-Dominique Leroux To cite this version: Marie-Dominique Leroux. Intensification rapide des cyclones tropicaux du sud-ouest de l’océan Indien (SWIO) : dynamique interne et influences externes. Physique Atmosphérique
