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

Abstract

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.

Physical Responses of Convective Heavy Rainfall to Future Warming Condition: Case Study of the Hiroshima Event

“…The fact that this rainfall system is not intensified is in marked contrast to the previous studies focusing on the effect of global warming on tropical cyclones (e.g., Kanada et al, 2017), which revealed that tropical cyclones and associated rainfall intensify in the future. This difference strongly suggests that the physical responses of meteorological phenomena causing heavy rainfall to a warmer climatic condition differ depending on their types and physical mechanisms.…”

“…The moisture increase does not only increase the total amount of precipitation linearly but also can change the flow field of particular meteorological phenomena, e.g., intensification of tropical cyclones (Takayabu et al, 2015), which suggests the possibility that more moisture from the surrounding areas is provided and converted to rainfall (Kanada et al, 2017). Therefore, in the case of tropical cyclones, the associated precipitation amount is expected to increase over the C-C relation.…”

Numerical Simulation of Heavy Rainfall in August 2014 over Japan and Analysis of Its Sensitivity to Sea Surface Temperature

“…The area of Japan was divided into eight regions consisting of Hokkaido, Tohoku, Kanto, Chubu, Kinki, Chugoku, Shikoku, and Kyushu. The numbers of observatories in these regions are 18,17,17,26,15,14,9, and 31, respectively.…”

“…From these results, we decided to conduct the SST change experiment under the optimal setting with the nudging only for horizontal wind components, as well as the horizontal resolution of 5 km and without the cumulus scheme, namely W_5km case. The horizontal resolution of around 5 km has been widely used in previous studies [11,18,24,31,56]. The W_5km case captured the amount of precipitation in the extreme heavy rainfall due to typhoons in the Shikoku region being the best From these results, we decided to conduct the SST change experiment under the optimal setting with the nudging only for horizontal wind components, as well as the horizontal resolution of 5 km and without the cumulus scheme, namely W_5km case.…”

On the Influence of Global Warming on Atlantic Hurricane Frequency

“…There is also an extended debate regarding the overall change in the activity of storms. In particular, variations in frequency and intensity of extreme storms, possibly due to the global warming, are at the focus of this scientific and societal debate (Knutson and Tuleya, 2004;Bender et al, 2010;Knutson et al, 2013Knutson et al, , 2015Kanada et al, 2017). Tropical Cyclones (TC) and hurricanes are among the most destructive kinds of storms in nature.…”