scholarly journals Future Changes in Structures of Extremely Intense Tropical Cyclones Using a 2-km Mesh Nonhydrostatic Model

2013 ◽  
Vol 26 (24) ◽  
pp. 9986-10005 ◽  
Author(s):  
Sachie Kanada ◽  
Akiyoshi Wada ◽  
Masato Sugi
Keyword(s):  
Global Warming ◽  
Tropical Cyclones ◽  
General Circulation ◽  
Potential Temperature ◽  
Circulation Model ◽  
Future Climate ◽  
Central Pressure ◽  
Near Surface ◽  
Nonhydrostatic Model ◽  
The Future

Abstract Recent studies have projected that global warming may lead to an increase in the number of extremely intense tropical cyclones. However, how global warming affects the structure of extremely intense tropical cyclones has not been thoroughly examined. This study defines extremely intense tropical cyclones as having a minimum central pressure below 900 hPa and investigates structural changes in the inner core and thereby changes in the intensity in the future climate. A 2-km mesh nonhydrostatic model (NHM2) is used to downscale the 20-km mesh atmospheric general circulation model projection forced with a control scenario and a scenario of twenty-first-century climate change. The eyewall region of extremely intense tropical cyclones simulated by NHM2 becomes relatively smaller and taller in the future climate. The intense near-surface inflow intrudes more inward toward the eye. The heights and the radii of the maximum wind speed significantly decrease and an intense updraft area extends from the lower level around the leading edge of thinner near-surface inflows, where the equivalent potential temperature substantially increases in the future climate. Emanuel’s potential intensity theory suggests that about half of the intensification (increase in central pressure fall) is explained by the changes in the atmospheric environments and sea surface temperature, while the remaining half needs to be explained by other processes. It is suggested that the structural change projected by NHM2, which is significant within a radius of 50 km, is playing an important role in the intensification of extremely intense tropical cyclones in simulations of the future climate.

scholarly journals Summertime precipitation in Hokkaido and Kyushu, Japan in response to global warming

2021 ◽  
Author(s):  
Daichi Takabatake ◽  
Masaru Inatsu
Keyword(s):  
Global Warming ◽  
Tropical Cyclones ◽  
General Circulation ◽  
Dynamical Downscaling ◽  
Circulation Model ◽  
Policy Decision ◽  
Moisture Flux ◽  
Specific Humidity ◽  
Future Climate Change ◽  
Moisture Flux Convergence

Abstract We analyzed a large ensemble dataset called the database for Policy Decision Making for Future climate change (d4PDF), which contains 60-km resolution atmospheric general circulation model output and 20-km resolution dynamical downscaling for the Japanese domain. The increase in moisture and precipitation, and their global warming response in June–July–August were described focusing on the differences between Hokkaido and Kyushu. The results suggested that the specific humidity increased almost following the Clausius Clapeyron relation, but the change in stationary circulation suppressed the precipitation increase, except for in western Kyushu. The + 4 K climate in Hokkaido would be as hot and humid as the present climate in Kyushu. The circulation change related to the southward shift of the jet stream and an eastward shift of the Bonin high weakened the moisture flux convergence via a stationary field over central Japan including eastern Kyushu. The transient eddy activity counteracted the increase in humidity, so that the moisture flux convergence and precipitation did not change much over Hokkaido. Because the contribution of tropical cyclones to the total precipitation was at most 10%, the decrease in the number of tropical cyclones did not explain the predicted change in precipitation.

A Multimodel Intercomparison of an Intense Typhoon in Future, Warmer Climates by Four 5-km-Mesh Models

2017 ◽  
Vol 30 (15) ◽  
pp. 6017-6036 ◽  
Author(s):  
Sachie Kanada ◽  
Tetsuya Takemi ◽  
Masaya Kato ◽  
Shota Yamasaki ◽  
Hironori Fudeyasu ◽  
...  
Keyword(s):  
Water Vapor ◽  
Boundary Conditions ◽  
General Circulation ◽  
Mesoscale Model ◽  
Future Climate ◽  
Japan Meteorological Agency ◽  
Near Surface ◽  
Control Simulation ◽  
The Future ◽  
Initial And Boundary Conditions

Intense tropical cyclones (TCs) sometimes cause huge disasters, so it is imperative to explore the impacts of climate change on such TCs. Therefore, the authors conducted numerical simulations of the most destructive historical TC in Japanese history, Typhoon Vera (1959), in the current climate and a global warming climate. The authors used four nonhydrostatic models with a horizontal resolution of 5 km: the cloud-resolving storm simulator, the fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model, the Japan Meteorological Agency (JMA) operational nonhydrostatic mesoscale model, and the Weather Research and Forecasting Model. Initial and boundary conditions for the control simulation were provided by the Japanese 55-year Reanalysis dataset. Changes between the periods of 1979–2003 and 2075–99 were estimated from climate runs of a 20-km-mesh atmospheric general circulation model, and these changes were added to the initial and boundary conditions of the control simulation to produce the future climate conditions. Although the representation of inner-core structures varies largely between the models, all models project an increase in the maximum intensity of future typhoons. It is found that structural changes only appeared around the storm center with sudden changes in precipitation and near-surface wind speeds as the radius of maximum wind speed (RMW) contracted. In the future climate, the water vapor mixing ratio in the lower troposphere increased by 3–4 g kg−1. The increased water vapor allowed the eyewall updrafts to form continuously inside the RMW and contributed to rapid condensation in the taller and more intense updrafts.

Evaluation of climate change impacts and adaptation strategies for maize cultivation in the Himalayan foothills of India

2015 ◽  
Vol 6 (3) ◽  
pp. 596-614 ◽  
Author(s):  
Proloy Deb ◽  
Anthony S. Kiem ◽  
Mukand S. Babel ◽  
Sang Thi Chu ◽  
Biplab Chakma
Keyword(s):  
Climate Change ◽  
General Circulation ◽  
Circulation Model ◽  
Maize Yield ◽  
Future Climate ◽  
Future Climate Change ◽  
Daily Maximum ◽  
Study Region ◽  
Supplementary Irrigation ◽  
The Future

This study evaluates the impacts of climate change on rainfed maize (Zea mays) yield and evaluates different agro-adaptation measures to counteract its negative impacts at Sikkim, a Himalayan state of India. Future climate scenarios for the 10 years centered on 2025, 2055 and 2085 were obtained by downscaling the outputs of the HadCM3 General Circulation Model (GCM) under for A2 and B2 emission scenarios. HadCM3 was chosen after assessing the performance analysis of six GCMs for the study region. The daily maximum and minimum temperatures are projected to rise in the future and precipitation is projected to decrease (by 1.7 to 22.6% relative to the 1991–2000 baseline) depending on the time period and scenarios considered. The crop simulation model CERES-Maize was then used to simulate maize yield under future climate change for the future time windows. Simulation results show that climate change could reduce maize productivity by 10.7–18.2%, compared to baseline yield, under A2 and 6.4–12.4% under B2 scenarios. However, the results also indicate that the projected decline in maize yield could be offset by early planting of seeds, lowering the farm yard manure application rate, introducing supplementary irrigation and shifting to heat tolerant varieties of maize.

The Arctic cryosphere in the Mid-Pliocene and the future

2008 ◽  
Vol 367 (1886) ◽  
pp. 49-67 ◽  
Author(s):  
Daniel J Lunt ◽  
Alan M Haywood ◽  
Gavin L Foster ◽  
Emma J Stone
Keyword(s):  
Climate Change ◽  
General Circulation ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Circulation Model ◽  
Future Climate ◽  
Arctic Climate ◽  
The Arctic ◽  
Future Climate Change ◽  
The Future

The Mid-Pliocene ( ca 3 Myr ago) was a relatively warm period, with increased atmospheric CO 2 relative to pre-industrial. It has therefore been highlighted as a possible palaeo-analogue for the future. However, changed vegetation patterns, orography and smaller ice sheets also influenced the Mid-Pliocene climate. Here, using a general circulation model and ice-sheet model, we determine the relative contribution of vegetation and soils, orography and ice, and CO 2 to the Mid-Pliocene Arctic climate and cryosphere. Compared with pre-industrial, we find that increased Mid-Pliocene CO 2 contributes 35 per cent, lower orography and ice-sheet feedbacks contribute 42 per cent, and vegetation changes contribute 23 per cent of Arctic temperature change. The simulated Mid-Pliocene Greenland ice sheet is substantially smaller than that of modern, mostly due to the higher CO 2 . However, our simulations of future climate change indicate that the same increase in CO 2 is not sufficient to melt the modern ice sheet substantially. We conclude that, although the Mid-Pliocene resembles the future in some respects, care must be taken when interpreting it as an exact analogue due to vegetation and ice-sheet feedbacks. These act to intensify Mid-Pliocene Arctic climate change, and act on a longer time scale than the century scale usually addressed in future climate prediction.

Different Climatological Characteristics, Inner-Core Structures, and Intensification Processes of Simulated Intense Tropical Cyclones between 20-km Global and 5-km Regional Models

2017 ◽  
Vol 30 (5) ◽  
pp. 1583-1603 ◽  
Author(s):  
Sachie Kanada ◽  
Akiyoshi Wada
Keyword(s):  
Tropical Cyclones ◽  
General Circulation ◽  
Large Scale ◽  
Atmospheric General Circulation Model ◽  
Inner Core ◽  
Circulation Model ◽  
Maximum Intensity ◽  
Rapid Intensification ◽  
Nonhydrostatic Model ◽  
Before And After

Abstract Climatological characteristics of simulated intense tropical cyclones (TCs) in the western North Pacific were explored with a 20-km-mesh atmospheric general circulation model (AGCM20) and a 5-km-mesh regional atmospheric nonhydrostatic model (ANHM5). From the AGCM20 climate runs, 34 intense TCs with a minimum central pressure (MCP) less than or equal to 900 hPa were sampled. Downscaling experiments were conducted with the ANHM5 for each intense TC simulated by the AGCM20. Only 23 developed into TCs with MCP ≤ 900 hPa. Most of the best-track TCs with an MCP ≤ 900 hPa underwent rapid intensification (RI) and attained maximum intensities south of 25°N. The AGCM20 simulated a similar number of intense TCs as the best-track datasets. However, the intense AGCM20 TCs tended to intensify longer and more gradually; only half of them underwent RI. The prolonged gradual intensification resulted in significant northward shifts of the location of maximum intensity compared with the location derived from two best-track datasets. The inner-core structure of AGCM20 TCs exhibited weak and shallow eyewall updrafts with maxima below an altitude of 6 km, while downscaling experiments revealed that most of the intense ANHM5 TCs underwent RI with deep and intense eyewall updrafts and attained their maximum intensity at lower latitudes. The altitudes of updraft maxima simulated by the AGCM20 descended rapidly during the phase of greatest intensification as midlevel warming markedly developed. The change in major processes responsible for precipitation in AGCM20 TCs before and after maximum intensification suggests close relationships between the large-scale cloud scheme and midlevel warming and prolonged gradual intensification.

scholarly journals Impacts of Global Warming on Meiyu-Baiu Extreme Rainfall and Associated Mid-Latitude Synoptic-Scale Systems as Inferred From 20km AGCM Simulations

2021 ◽  
Author(s):  
Ka Wai So ◽  
Chi-Yung Tam ◽  
Ngar-Cheung Lau
Keyword(s):  
Global Warming ◽  
Extreme Precipitation ◽  
General Circulation ◽  
Eastern China ◽  
Circulation Model ◽  
Extreme Rainfall ◽  
Static Stability ◽  
Synoptic Scale ◽  
Climate Simulations ◽  
The Future

Abstract The impacts of global warming on Meiyu-Baiu extreme rainfall and the associated mid-latitude synoptic-scale weather systems over the Eastern China (EC) and the Baiu rainband (Bu) regions in East Asia have been examined, based on simulations from the 20-km Meteorological Research Institute atmospheric general circulation model (MRI-AGCM3.2S). This model was demonstrated to give realistic Asian extreme rainfall, when compared with data from the Tropical Rainfall Measuring Mission (TRMM). Here we used a novel wave-selection algorithm based on the 300hPa wind, in order to identify upper-level propagating wave signals in conjunction with the occurrence of extreme precipitation in either EC or Bu. The same algorithm was applied for both the present (1979-2003) and future (2075-2099) climate simulations from the AGCM, so as to infer the impacts of global warming on the behavior of these systems. Results show robust decrease of intensity of systems influencing both Bu and EC in the future warmer climate. Their corresponding low-to-mid level circulation, as revealed by vertical velocity, temperature advection and sea-level pressure composites, was also found to be weakened. This is likely related to changes in the background circulation in future over the East Asian mid-latitude zone, such as the widespread increment of the seasonal mean static stability at 500 hPa. However, the wave-associated precipitation over these regions was enhanced in the future climate simulations. This can be attributed to more strong intensity rainfall, which increases as the background temperature in these regions warms, largely following the Clausius-Clapeyron relation. Therefore, changes of wave-related extreme precipitation in EC and Bu are mainly controlled by the thermodynamic effect; the latter appears to be much stronger than the potential impacts due to the slight weakening of these weather systems.

scholarly journals Response of Ice and Liquid Water Paths of Tropical Cyclones to Global Warming Simulated by a Global Nonhydrostatic Model with Explicit Cloud Microphysics

2013 ◽  
Vol 26 (24) ◽  
pp. 9931-9945 ◽  
Author(s):  
Yohei Yamada ◽  
Masaki Satoh
Keyword(s):  
Global Warming ◽  
Tropical Cyclones ◽  
Liquid Water ◽  
Cloud Microphysics ◽  
Future Climate ◽  
Cumulus Parameterization ◽  
Simulation Data ◽  
Nonhydrostatic Model ◽  
Ice Water ◽  
Future Climate Projection

Abstract Cloud feedback plays a key role in the future climate projection. Using global nonhydrostatic model (GNHM) simulation data for a present-day [control (CTL)] and a warmer [global warming (GW)] experiment, the authors estimate the contribution of tropical cyclones (TCs) to ice water paths (IWP) and liquid water paths (LWP) associated with TCs and their changes between CTL and GW experiments. They use GNHM with a 14-km horizontal mesh for explicitly calculating cloud microphysics without cumulus parameterization. This dataset shows that the cyclogenesis under GW conditions reduces to approximately 70% of that under CTL conditions, as shown in a previous study, and the tropical averaged IWP (LWP) is reduced by approximately 2.76% (0.86%). Horizontal distributions of IWP and LWP changes seem to be closely related to TC track changes. To isolate the contributions of IWP/LWP associated with TCs, the authors first examine the radial distributions of IWP/LWP from the TC center at their mature stages and find that they generally increase for more intense TCs. As the intense TC in GW increases, the IWP and LWP around the TC center in GW becomes larger than that in CTL. The authors next define the TC area as the region within 500 km from the TC center at its mature stages. They find that the TC’s contribution to the total tropical IWP (LWP) is 4.93% (3.00%) in CTL and 5.84% (3.69%) in GW. Although this indicates that the TC’s contributions to the tropical IWP/LWP are small, IWP/LWP changes in each basin behave in a manner similar to those of the cyclogenesis and track changes under GW.

scholarly journals FUTURE CLIMATE EXPERIMENTS ON INTENSITY AND STORM SURGE OF TYPHOON SANBA (2012)

2018 ◽  
pp. 54
Author(s):  
Masaya Toyoda ◽  
Jun Yoshino ◽  
Tomonao Kobayashi
Keyword(s):  
Global Warming ◽  
Tropical Cyclones ◽  
Storm Surge ◽  
Climate Model ◽  
Regional Climate ◽  
Storm Surges ◽  
Future Climate ◽  
Typhoon Intensity ◽  
The Future ◽  
The Impact

The recent progress of the global warming raise concerns the future changes of tropical cyclones (i.e. hurricane, typhoon, and cyclone) and their associated coastal disasters. It is thought that the increases of both the sea surface temperature and ocean heat contents by the global warming could increase the intensity of future tropical cyclones. As a method of quantitative assessment for the impact of global warming on tropical cyclones and their storm surges, “pseudo-global warming downscaling” is generally adopted using a regional climate model and a storm surge model (Takayabu et al., 2015). Estimating the differences of experiments between present and future climate, we can quantify the future changes of typhoon intensity and storm surge by the global warming. Using the high-resolution typhoon model, we carry out a present climate experiment and pseudo-global warming experiments on typhoon intensity and its storm surge of Typhoon Sanba (2012) in this study. Sanba went northward on the west coast of Kyushu Island and caused a storm surge in Ariake Sea, Japan. Sanba had a minimum central pressure of 900 hPa and a maximum wind speed of 55 m/s. The observed maximum sea level anomaly was 104 cm at Oura, Saga Prefecture. To evaluate the impacts of global warming differences (GWDs) on typhoon intensity and storm surge, sensitivity experiments on different months (August, September, and October) in future typhoon season are also made.

scholarly journals Estimating the Continental Response to Global Warming Using Pattern-Scaled Sea Surface Temperatures and Sea Ice

2016 ◽  
Vol 29 (24) ◽  
pp. 9125-9139 ◽  
Author(s):  
Adeline Bichet ◽  
Paul J. Kushner ◽  
Lawrence Mudryk
Keyword(s):  
Global Warming ◽  
Sea Ice ◽  
General Circulation ◽  
Circulation Model ◽  
Tropical Indian Ocean ◽  
Sea Surface ◽  
Climate Projections ◽  
Western Boundary ◽  
Sea Ice Concentration ◽  
Continental Climate

Abstract Better constraining the continental climate response to anthropogenic forcing is essential to improve climate projections. In this study, pattern scaling is used to extract, from observations, the patterned response of sea surface temperature (SST) and sea ice concentration (SICE) to anthropogenically dominated long-term global warming. The SST response pattern includes a warming of the tropical Indian Ocean, the high northern latitudes, and the western boundary currents. The SICE pattern shows seasonal variations of the main locations of sea ice loss. These SST–SICE response patterns are used to drive an ensemble of an atmospheric general circulation model, the National Center for Atmospheric Research (NCAR) Community Atmosphere Model, version 5 (CAM5), over the period 1980–2010 along with a standard AMIP ensemble using observed SST—SICE. The simulations enable attribution of a variety of observed trends of continental climate to global warming. On the one hand, the warming trends observed in all seasons across the entire Northern Hemisphere extratropics result from global warming, as does the snow loss observed over the northern midlatitudes and northwestern Eurasia. On the other hand, 1980–2010 precipitation trends observed in winter over North America and in summer over Africa result from the recent decreasing phase of the Pacific decadal oscillation and the recent increasing phase of the Atlantic multidecadal oscillation, respectively, which are not part of the global warming signal. The method holds promise for near-term decadal climate prediction but as currently framed cannot distinguish regional signals associated with oceanic internal variability from aerosol forcing and other sources of short-term forcing.

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