Combined Effects of Synoptic-Scale Teleconnection Patterns on Summer Precipitation in Southern China

Using ERA-Interim daily reanalysis and precipitation data, the combined effects of East Asia-Pacific (EAP) and Silk Road (SR) teleconnection patterns on summer precipitation in Southern China were investigated on synoptic to sub-monthly timescales. Combined EAP and SR patterns lead to more persisten...

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Main Authors: Chao Wang, Lijuan Wang
Format: Article
Language:English
Published: MDPI AG 2018-04-01
Series:Atmosphere
Subjects:
Online Access:http://www.mdpi.com/2073-4433/9/4/154
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author Chao Wang
Lijuan Wang
author_facet Chao Wang
Lijuan Wang
author_sort Chao Wang
collection DOAJ
description Using ERA-Interim daily reanalysis and precipitation data, the combined effects of East Asia-Pacific (EAP) and Silk Road (SR) teleconnection patterns on summer precipitation in Southern China were investigated on synoptic to sub-monthly timescales. Combined EAP and SR patterns lead to more persistent and extreme precipitation in the Yangtze River Valley (YRV) and exhibit an obvious zonal advance between the South Asia High (SAH) and Western Pacific Subtropical High (WPSH) prior to its onset. During typical combined events, an overlap between the SAH and WPSH remains in a favorable position for Persistent Extreme Precipitation (PEP). Furthermore, SR-induced acceleration of the westerly jet stream and extra positive vorticity advection provide persistent upper-level divergence for YRV precipitation. An anomalous EAP-related cyclone/anticyclone pair over East Asia induces enhanced low-level southwesterlies to the northern anticyclone flank and northerlies from the mid-latitudes, advecting anomalously abundant moisture toward the YRV, resulting in clear moisture convergence. Moreover, the strong ascent of warmer/moister air along a quasi-stationary front may be crucial for PEP. During decay, the SAH and WPSH diverge from each other and retreat to their normal positions, and the strong ascent of warmer/moister air rapidly weakens to dissipation, terminating PEP in the YRV.
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spelling doaj.art-79de3129d76a4b5c905f2e12f0eee8b72022-12-21T19:18:50ZengMDPI AGAtmosphere2073-44332018-04-019415410.3390/atmos9040154atmos9040154Combined Effects of Synoptic-Scale Teleconnection Patterns on Summer Precipitation in Southern ChinaChao Wang0Lijuan Wang1Key Laboratory of Meteorological Disaster, Ministry of Education (KLME)/Joint International Research Laboratory of Climate and Environment Change (ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD)/Science and Technology Innovation Team on Climate Simulation and Forecast, Nanjing University of Information Science & Technology, Nanjing 210044, ChinaKey Laboratory of Meteorological Disaster, Ministry of Education (KLME)/Joint International Research Laboratory of Climate and Environment Change (ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD)/Science and Technology Innovation Team on Climate Simulation and Forecast, Nanjing University of Information Science & Technology, Nanjing 210044, ChinaUsing ERA-Interim daily reanalysis and precipitation data, the combined effects of East Asia-Pacific (EAP) and Silk Road (SR) teleconnection patterns on summer precipitation in Southern China were investigated on synoptic to sub-monthly timescales. Combined EAP and SR patterns lead to more persistent and extreme precipitation in the Yangtze River Valley (YRV) and exhibit an obvious zonal advance between the South Asia High (SAH) and Western Pacific Subtropical High (WPSH) prior to its onset. During typical combined events, an overlap between the SAH and WPSH remains in a favorable position for Persistent Extreme Precipitation (PEP). Furthermore, SR-induced acceleration of the westerly jet stream and extra positive vorticity advection provide persistent upper-level divergence for YRV precipitation. An anomalous EAP-related cyclone/anticyclone pair over East Asia induces enhanced low-level southwesterlies to the northern anticyclone flank and northerlies from the mid-latitudes, advecting anomalously abundant moisture toward the YRV, resulting in clear moisture convergence. Moreover, the strong ascent of warmer/moister air along a quasi-stationary front may be crucial for PEP. During decay, the SAH and WPSH diverge from each other and retreat to their normal positions, and the strong ascent of warmer/moister air rapidly weakens to dissipation, terminating PEP in the YRV.http://www.mdpi.com/2073-4433/9/4/154Silk Road patternEast Asia-Pacific patternmoisture fluxvertical motion
spellingShingle Chao Wang
Lijuan Wang
Combined Effects of Synoptic-Scale Teleconnection Patterns on Summer Precipitation in Southern China
Atmosphere
Silk Road pattern
East Asia-Pacific pattern
moisture flux
vertical motion
title Combined Effects of Synoptic-Scale Teleconnection Patterns on Summer Precipitation in Southern China
title_full Combined Effects of Synoptic-Scale Teleconnection Patterns on Summer Precipitation in Southern China
title_fullStr Combined Effects of Synoptic-Scale Teleconnection Patterns on Summer Precipitation in Southern China
title_full_unstemmed Combined Effects of Synoptic-Scale Teleconnection Patterns on Summer Precipitation in Southern China
title_short Combined Effects of Synoptic-Scale Teleconnection Patterns on Summer Precipitation in Southern China
title_sort combined effects of synoptic scale teleconnection patterns on summer precipitation in southern china
topic Silk Road pattern
East Asia-Pacific pattern
moisture flux
vertical motion
url http://www.mdpi.com/2073-4433/9/4/154
work_keys_str_mv AT chaowang combinedeffectsofsynopticscaleteleconnectionpatternsonsummerprecipitationinsouthernchina
AT lijuanwang combinedeffectsofsynopticscaleteleconnectionpatternsonsummerprecipitationinsouthernchina