Future changes in tropical cyclone activity projected by the new high-resolution MRI-AGCM* (original) (raw)
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Tellus Series A-dynamic Meteorology and Oceanography, 2008
Using the Yearly Genesis Parameter (YGP) and the Convective-YGP (CYGP), the main large-scale climatic fields controlling tropical cyclone (TC) formation are analysed and used to infer the number of TCs in a given basin using ERA40 reanalyses for the period 1983-2002. Both indices show a reasonable global number and spatial distribution of implied TCs compared to observations. Using the same approach, we evaluate TC activity in the last 20-yr period of the 20th century in an ensemble of nine Coupled Global Climate Model simulations submitted to the IPCC AR4. We extend this analysis backwards in time, through the 20th century, and find the ensemble derived CYGP suggests no trend in inferred TC numbers while the YGP, after applying a correction to compensate for its oversensitivity to sea surface temperature, suggests a small upward trend. Both indices give a fair geographical distribution of cyclogenesis. Finally, we assess future TC trends using three emission scenarios. Using the CYGP, which appears the most robust index for application to climate change, a small increase is predicted in the northwestern Pacific in the A1B and A2 scenarios.
Journal of Climate, 2014
How tropical cyclone (TC) activity in the northwestern Pacific might change in a future climate is assessed using multidecadal Atmospheric Model Intercomparison Project (AMIP)-style and time-slice simulations with the ECMWF Integrated Forecast System (IFS) at 16-km and 125-km global resolution. Both models reproduce many aspects of the present-day TC climatology and variability well, although the 16-km IFS is far more skillful in simulating the full intensity distribution and genesis locations, including their changes in response to El Niño–Southern Oscillation. Both IFS models project a small change in TC frequency at the end of the twenty-first century related to distinct shifts in genesis locations. In the 16-km IFS, this shift is southward and is likely driven by the southeastward penetration of the monsoon trough/subtropical high circulation system and the southward shift in activity of the synoptic-scale tropical disturbances in response to the strengthening of deep convective...
Response of Tropical Cyclone Potential Intensity to a Global Warming Scenario in the IPCC AR4 GCMs.
Journal of Climate, 2010
This paper reports on an analysis of the tropical cyclone (TC) potential intensity (PI) and its control parameters in transient global warming simulations. Specifically, the TC PI is calculated for phase 3 of the Coupled Model Intercomparison Project (CMIP3) integrations during the first 70 yr of a transient run forced by a 1% yr 21 CO 2 increase. The linear trend over the period is used to project a 70-yr change in relevant model parameters. The results for a 15-model ensemble-mean climate projection show that the thermodynamic potential intensity (THPI) increases on average by 1.0% to ;3.1% over various TC basins, which is mainly attributed to changes in the disequilibrium in enthalpy between the ocean and atmosphere in the transient response to increasing CO 2 concentrations. This modest projected increase in THPI is consistent with that found in other recent studies.
Recent improvements in the theoretical understanding of the relationship between tropical cyclones (TCs) and their large-scale environments have resulted in signi cant improvements in the skill for forecasting TC activity at daily and seasonal time-scales. However, future changes in TC activity under a warmer climate remain uncertain, particularly in terms of TC genesis locations and subsequent pathways. Applying a track-pattern-based statistical model to 22 Coupled Model Intercomparison Project Phase 5 (CMIP5) model runs for the historical period and the future period corresponding to the Representative Concentration Pathway 8.5 emissions scenarios, this study shows that in future climate conditions, TC passage frequency will decrease over the North Atlantic, particularly in the Gulf of Mexico, but will increase over the western North Paci c, especially that hits Korea and Japan. Unlike previous studies based on ne-resolution models, an ensemble mean of CMIP5 models projects an increase in TC activity in the western North Paci c, which is owing to enhanced subtropical deep convection and favorable dynamic conditions therein in conjunction with the expansion of the tropics and vice versa for the North Atlantic. Our results suggest that North America will experience less TC landfalls, while northeast Asia will experience more TCs than in the present-day climate.
Response of tropical cyclone potential intensity to a global warming scenario in the IPCC AR4 CGCMs
2010
This paper reports on an analysis of the tropical cyclone (TC) potential intensity (PI) and its control parameters in transient global warming simulations. Specifically, the TC PI is calculated for phase 3 of the Coupled Model Intercomparison Project (CMIP3) integrations during the first 70 yr of a transient run forced by a 1% yr 21 CO 2 increase. The linear trend over the period is used to project a 70-yr change in relevant model parameters. The results for a 15-model ensemble-mean climate projection show that the thermodynamic potential intensity (THPI) increases on average by 1.0% to ;3.1% over various TC basins, which is mainly attributed to changes in the disequilibrium in enthalpy between the ocean and atmosphere in the transient response to increasing CO 2 concentrations. This modest projected increase in THPI is consistent with that found in other recent studies.
Tropical Cyclone Changes in the Western North Pacific in a Global Warming Scenario
Journal of Climate, 2007
The influence of global warming on the climatology of tropical cyclones in the western North Pacific basin is examined using the high-resolution International Pacific Research Center (IPRC) regional climate model forced by ocean temperatures and horizontal boundary fields taken from the NCAR Community Climate System Model version 2 (CCSM2) coupled global climate model. The regional model is first tested in 10 yr of simulation with boundary forcing taken from observations and is shown to produce a reasonably good representation of the observed statistics of tropical cyclone numbers and locations. The model was then run for 10 yr with forcing from a present-day control run of the CCSM2 and then for 10 yr with forcing fields taken from the end of a long run with 6 times the present-day atmospheric CO 2 concentration. The global-mean surface air temperature warming in the perturbed run is 4.5 K, while the surface warming in the tropical western North Pacific is about 3 K. The results of these experiments reveal no statistically significant change in basinwide tropical cyclone numbers in the peak season from July to October in response to the CO 2 increase. However, a pronounced and statistically significant increase in tropical cyclone occurrence in the South China Sea is found. While the basinwide total number of storms remains nearly unchanged in the warm climate, there is a statistically significant increase in the average strength of the cyclones and in the number of the storms in the strongest wind categories.
Tropical Cyclones and Global Climate Change: A Post-IPCC Assessment
Bulletin of the American Meteorological Society, 1998
The very limited instrumental record makes extensive analyses of the natural variability of global tropical cyclone activities difficult in most of the tropical cyclone basins. However, in the two regions where reasonably reliable records exist (the North Atlantic and the western North Pacific), substantial multidecadal variability (particularly for intense Atlantic hurricanes) is found, but there is no clear evidence of long-term trends. Efforts have been initiated to use geological and geomorphological records and analysis of oxygen isotope ratios in rainfall recorded in cave stalactites to establish a paleoclimate of tropical cyclones, but these have not yet produced definitive results. Recent thermodynamical estimation of the maximum potential intensities (MPI) of tropical cyclones shows good agreement with observations.
Geophysical Research Letters, 2010
1] Tropical cyclone (TC) activity change due to global warming (GW) has been investigated using general circulation models. However, they involve uncertainty in treating the ensemble effects of deep convections. Here we sidestep such uncertainty by using a global cloud-systemresolving model (GCRM) and assess TC changes with a time-slice experiment for the present-day and future GW experiments spanning 5 months each. The results support the Intergovernmental Panel on Climate Change Fourth Assessment Report; reduction in global frequency but increase in more intense TCs. Consistent with recent studies, frequency is reduced over the North Atlantic due to intensified vertical wind shear. Over the Pacific, frequency is almost unchanged and the genesis location shifts eastward under the prescribed El-Niño like sea surface temperature change. With the GCRM's advantage of representing mesoscale properties, we find that the cloud height becomes taller for more intense TCs and that this relationship is strengthened with GW. Citation: Yamada, Y., K. Oouchi, M. Satoh, H. Tomita, and W. Yanase (2010), Projection of changes in tropical cyclone activity and cloud height due to greenhouse warming: Global cloud-system-resolving approach, Geophys.
Journal of Climate, 2020
The evolution of tropical cyclone activity under climate change remains a crucial scientific issue. Physical theory of cyclogenesis is limited, observational datasets suffer from heterogeneities in space and time, and state-of-the-art climate models used for future projections are still too coarse (~100 km of resolution) to simulate realistic systems. Two approaches can nevertheless be considered: 1) perform dedicated high-resolution (typically <50 km) experiments in which tropical cyclones can be tracked and 2) assess cyclone activity from existing low-resolution multimodel climate projections using large-scale indices as proxies. Here we explore these two approaches with a particular focus on the southern Indian Ocean. We first compute high-resolution experiments using the rotated-stretched configuration of our climate model (CNRM-CM6-1), which is able to simulate realistic tropical cyclones. In a 2-K warmer world, the model projects a 20% decrease in the frequency of tropical ...