scholarly journals Dependence of the relationship between the tropical cyclone track and western Pacific subtropical high intensity on initial storm size: A numerical investigation

2015 ◽  
Vol 120 (22) ◽  
pp. 11,451-11,467 ◽  
Author(s):  
Yuan Sun ◽  
Zhong Zhong ◽  
Lan Yi ◽  
Tim Li ◽  
Ming Chen ◽  
...  
Keyword(s):  
Tropical Cyclone ◽  
Numerical Investigation ◽  
High Intensity ◽  
Western Pacific Subtropical High ◽  
Western Pacific ◽  
Subtropical High ◽  
Cyclone Track ◽  
Tropical Cyclone Track ◽  
The Relationship

scholarly journals Has the Western Pacific Subtropical High Extended Westward since the Late 1970s?

2015 ◽  
Vol 28 (13) ◽  
pp. 5406-5413 ◽  
Author(s):  
Liguang Wu ◽  
Chao Wang
Keyword(s):  
Tropical Cyclone ◽  
North Pacific ◽  
Geopotential Height ◽  
Western North Pacific ◽  
Western Pacific Subtropical High ◽  
Summer Rainfall ◽  
Western Pacific ◽  
Subtropical High ◽  
Global Trend ◽  
Summer Rainfall Over China

Abstract Previous studies reported that the summer western Pacific subtropical high (WPSH) has extended westward since the late 1970s and the change has affected summer rainfall over China and tropical cyclone prevailing tracks in the western North Pacific. The authors show that the 500-hPa geopotential height in the midlatitudes of the Northern Hemisphere has trended upward in the warming climate and the westward extension of the WPSH quantified with the 500-hPa geopotential height is mainly a manifestation of the global rising trend. That is, the summer 500-hPa WPSH has not remarkably extended westward since the late 1970s when the global trend is removed. It is suggested that the index that indicates the west–east shift of the summer 500-hPa WPSH should be redefined and that further investigation is needed to understand the observed climate change in the summer rainfall over China and tropical cyclone prevailing tracks in the western North Pacific.

Sensitivity of Tropical Cyclone Feedback on the Intensity of the Western Pacific Subtropical High to Microphysics Schemes

2015 ◽  
Vol 72 (4) ◽  
pp. 1346-1368 ◽  
Author(s):  
Yuan Sun ◽  
Zhong Zhong ◽  
Wei Lu
Keyword(s):  
Tropical Cyclone ◽  
Critical Role ◽  
Western Pacific Subtropical High ◽  
Melting Process ◽  
Western Pacific ◽  
Subtropical High ◽  
Freezing Level ◽  
Arw Model ◽  
Microphysical Parameterization ◽  
The Western Pacific

Abstract The Advanced Research version of Weather Research and Forecasting (WRF-ARW) Model is used to examine the sensitivity of a simulated tropical cyclone (TC) track and the associated intensity of the western Pacific subtropical high (WPSH) to microphysical parameterization (MP) schemes. It is found that the simulated WPSH is sensitive to MP schemes only when TCs are active over the western North Pacific. WRF fails to capture TC tracks because of errors in the simulation of the WPSH intensity. The failed simulation of WPSH intensity and TC track can be attributed to the overestimated convection in the TC eyewall region, which is caused by inappropriate MP schemes. In other words, the MP affects the simulation of the TC activity, which influences the simulation of WPSH intensity and, thus, TC track. The feedback of the TC to WPSH plays a critical role in the model behavior of the simulation. Further analysis suggests that the overestimated convection in the TC eyewall results in excessive anvil clouds and showers in the middle and upper troposphere. As the simulated TC approaches the WPSH, the excessive anvil clouds extend far away from the TC center and reach the area of the WPSH. Because of the condensation of the anvil clouds’ outflows and showers, a huge amount of latent heat is released into the atmosphere and warms the air above the freezing level at about 500 hPa. Meanwhile, the evaporative (melting) process of hydrometers in the descending flow takes place below the freezing level and cools the air in the lower and middle troposphere. As a result, the simulated WPSH intensity is weakened, and the TC turns northward earlier than in observations.

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