A Possible Cause of Tropical Cyclone Eastward Genesis Location Bias Study Using CAM5 Model in Western North Pacific
Abstract State‐of‐the‐art climate models are extremely useful tools, but they all have biases when simulating tropical cyclone (TC) genesis location. These biases contribute to discrepancies in simulating other characteristics of TC activities (e.g., track, intensity, and duration) and even the surr...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
American Geophysical Union (AGU)
2020-01-01
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| Series: | Earth and Space Science |
| Subjects: | |
| Online Access: | https://doi.org/10.1029/2019EA000955 |
| _version_ | 1818561021262954496 |
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| author | Yixuan Shen Yuan Sun Zhong Zhong Tim Li Yijia Hu Lan Yi |
| author_facet | Yixuan Shen Yuan Sun Zhong Zhong Tim Li Yijia Hu Lan Yi |
| author_sort | Yixuan Shen |
| collection | DOAJ |
| description | Abstract State‐of‐the‐art climate models are extremely useful tools, but they all have biases when simulating tropical cyclone (TC) genesis location. These biases contribute to discrepancies in simulating other characteristics of TC activities (e.g., track, intensity, and duration) and even the surrounding large‐scale circulation. The genesis potential index (GPI) is a useful tool to evaluate the performance of climate models in simulating TC genesis. Here, it is employed to investigate possible causes of simulation biases of TC genesis location in western North Pacific using the downscaled Community Atmosphere Model Version 5 (CAM5) climate model and observations. We find that GPI can reasonably describe the spatial pattern of TC genesis location in either observation or simulation. By having one of GPI‐related variables (i.e., low‐level absolute vorticity, middle‐level relative humidity, vertical wind shear, and potential intensity) change with the others set to stable while testing single variable, the contributions of environmental fields associated with GPI are examined and a possible cause of TC genesis biases is revealed. Due to the overestimated humidity in the east region of western North Pacific, the simulated GPI high value region is to the east of the observed one, and more TCs in the downscaled CAM5 model generate farther east than in observation. These results imply that the biases in simulated humidity and thus TC genesis location may be reduced by correcting the evaporation rate in the deep convection scheme, since the evaporation rate is closely related to environment humidity change as suggested by previous studies. |
| first_indexed | 2024-12-14T00:45:41Z |
| format | Article |
| id | doaj.art-e997132b9300450d8c2f22b5a3ebe166 |
| institution | Directory Open Access Journal |
| issn | 2333-5084 |
| language | English |
| last_indexed | 2024-12-14T00:45:41Z |
| publishDate | 2020-01-01 |
| publisher | American Geophysical Union (AGU) |
| record_format | Article |
| series | Earth and Space Science |
| spelling | doaj.art-e997132b9300450d8c2f22b5a3ebe1662022-12-21T23:24:09ZengAmerican Geophysical Union (AGU)Earth and Space Science2333-50842020-01-0171n/an/a10.1029/2019EA000955A Possible Cause of Tropical Cyclone Eastward Genesis Location Bias Study Using CAM5 Model in Western North PacificYixuan Shen0Yuan Sun1Zhong Zhong2Tim Li3Yijia Hu4Lan Yi5College of Meteorology and Oceanography National University of Defense Technology Nanjing ChinaCollege of Meteorology and Oceanography National University of Defense Technology Nanjing ChinaCollege of Meteorology and Oceanography National University of Defense Technology Nanjing ChinaJoint International Research Laboratory of Climate and Environmental Change (ILCEC) Nanjing University of Information Science and Technology Nanjing ChinaCollege of Meteorology and Oceanography National University of Defense Technology Nanjing ChinaChinese Academy of Meteorological Sciences/Chinese Meteorological Society Beijing ChinaAbstract State‐of‐the‐art climate models are extremely useful tools, but they all have biases when simulating tropical cyclone (TC) genesis location. These biases contribute to discrepancies in simulating other characteristics of TC activities (e.g., track, intensity, and duration) and even the surrounding large‐scale circulation. The genesis potential index (GPI) is a useful tool to evaluate the performance of climate models in simulating TC genesis. Here, it is employed to investigate possible causes of simulation biases of TC genesis location in western North Pacific using the downscaled Community Atmosphere Model Version 5 (CAM5) climate model and observations. We find that GPI can reasonably describe the spatial pattern of TC genesis location in either observation or simulation. By having one of GPI‐related variables (i.e., low‐level absolute vorticity, middle‐level relative humidity, vertical wind shear, and potential intensity) change with the others set to stable while testing single variable, the contributions of environmental fields associated with GPI are examined and a possible cause of TC genesis biases is revealed. Due to the overestimated humidity in the east region of western North Pacific, the simulated GPI high value region is to the east of the observed one, and more TCs in the downscaled CAM5 model generate farther east than in observation. These results imply that the biases in simulated humidity and thus TC genesis location may be reduced by correcting the evaporation rate in the deep convection scheme, since the evaporation rate is closely related to environment humidity change as suggested by previous studies.https://doi.org/10.1029/2019EA000955tropical cyclone genesiseastward bias of genesis locationgenesis potential indexdownscaled CAM5 modelWRF modeloverestimated humidity |
| spellingShingle | Yixuan Shen Yuan Sun Zhong Zhong Tim Li Yijia Hu Lan Yi A Possible Cause of Tropical Cyclone Eastward Genesis Location Bias Study Using CAM5 Model in Western North Pacific Earth and Space Science tropical cyclone genesis eastward bias of genesis location genesis potential index downscaled CAM5 model WRF model overestimated humidity |
| title | A Possible Cause of Tropical Cyclone Eastward Genesis Location Bias Study Using CAM5 Model in Western North Pacific |
| title_full | A Possible Cause of Tropical Cyclone Eastward Genesis Location Bias Study Using CAM5 Model in Western North Pacific |
| title_fullStr | A Possible Cause of Tropical Cyclone Eastward Genesis Location Bias Study Using CAM5 Model in Western North Pacific |
| title_full_unstemmed | A Possible Cause of Tropical Cyclone Eastward Genesis Location Bias Study Using CAM5 Model in Western North Pacific |
| title_short | A Possible Cause of Tropical Cyclone Eastward Genesis Location Bias Study Using CAM5 Model in Western North Pacific |
| title_sort | possible cause of tropical cyclone eastward genesis location bias study using cam5 model in western north pacific |
| topic | tropical cyclone genesis eastward bias of genesis location genesis potential index downscaled CAM5 model WRF model overestimated humidity |
| url | https://doi.org/10.1029/2019EA000955 |
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