Abstract
Increasing lines of evidence question the homogenous response of Asian Summer Monsoon (ASM) precipitation patterns, requiring rethinking of the forcing mechanisms. Here we show a ~15,000-year quantitative precipitation history based on well-dated lake levels at Lake Chenghai, subtropical China. Lake levels and the inferred precipitation were high during the Bølling-Allerød, early and late Holocene, but low during the middle Holocene. The orbital scale precipitation trend is out of phase with boreal summer insolation, the later has been widely suggested as the driver of ASM precipitation. Lake Chenghai long-term lake levels are synchronous with trends in tropical Pacific sea surface temperatures, the related zonal sea surface temperature gradients, and interhemispheric temperature gradients. We propose that changes in either the interhemispheric or zonal Pacific temperature gradients modulate the intensity and location of the western Pacific subtropical high, which is juxtaposed on the ASM, leading to heterogeneous hydroclimatic conditions over subtropical East Asia.
Original language | American English |
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Article number | e2019GL084705 |
Journal | Geophysical Research Letters |
Volume | 47 |
Issue number | 3 |
DOIs | |
State | Published - 16 Feb 2020 |
Bibliographical note
Funding Information:We thank Kathleen R. Johnson and another two anonymous reviewers for valuable comments and suggestions. This work is funded by the joint NSFC-ISF research program (NSFC grant 41761144070 and ISF grant 2487/17) and by the program (41672169) supported by the National Natural Science Foundation of China. Data are available via the NOAA online server.
Funding Information:
We thank Kathleen R. Johnson and another two anonymous reviewers for valuable comments and suggestions. This work is funded by the joint NSFC‐ISF research program (NSFC grant 41761144070 and ISF grant 2487/17) and by the program (41672169) supported by the National Natural Science Foundation of China. Data are available via the NOAA online server.
Publisher Copyright:
©2020. American Geophysical Union. All Rights Reserved.
Keywords
- Asian summer monsoon
- Lake Chenghai
- Western Pacific Subtropical High
- lake levels
- subtropical Asia
- temperature gradients