Relationship over southern China between the summer rainfall induced by tropical cyclones and that by monsoon
This study investigates the relationship between tropical cyclone–induced precipitation (P TC) and summer monsoon–induced precipitation (P SM) in southern China (SC) during June–August. The spatial patterns of the first interannual mode are uniform in sign over SC, with positive anomalies for P TC a...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
KeAi Communications Co., Ltd.
2017-01-01
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| Series: | Atmospheric and Oceanic Science Letters |
| Subjects: | |
| Online Access: | http://dx.doi.org/10.1080/16742834.2017.1248756 |
| Summary: | This study investigates the relationship between tropical cyclone–induced precipitation (P TC) and summer monsoon–induced precipitation (P SM) in southern China (SC) during June–August. The spatial patterns of the first interannual mode are uniform in sign over SC, with positive anomalies for P TC and negative anomalies for P SM. The background of an increase in cyclonic vorticity, an increase in RH, and a decrease in vertical wind shear over the South China Sea (SCS)–western north Pacific (WNP) provides favorable conditions for more TC genesis. The positive equatorial central Pacific SST anomaly and negative North Indian Ocean SST anomaly contribute to the anomalous cyclone over the SCS–WNP, which causes decreasing P SM in SC together with an anomalous anticyclone over eastern China–Japan. By contrast, whilst the spatial patterns of the first interdecadal mode are also uniform in sign over SC, there are positive anomalies for both P TC and P SM. The first interdecadal principal component features significant positive correlation with the number of TCs forming in the SCS. There is a significant increase in P TC and P SM after early 1990s. A positive tropical Indian Ocean (TIO) SST anomaly persists from the preceding winter to summer. During the preceding winter and spring after the early 1990s, a positive western Pacific SST anomaly can result in TIO SST warming through vertical circulation. Then, the positive TIO SST anomaly triggers an anomalous WNP anticyclone and contributes to the interdecadal increase in SC P SM in the succeeding summer. The persistent heating source over SC from May to summer related to an earlier onset of the SCS monsoon may strengthen the East Asian subtropical summer monsoon. |
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| ISSN: | 1674-2834 2376-6123 |