Page 182 - 《高原气象》2025年第5期

高 原 气 象 44 卷
1300

Synergistic Effects of Two Oceans on Interannual Anomalies

of Winter Precipitation in Xinjiang， China

LI Xinrong ， LI Liping ， LIU Yanju ， REN Jinghua 4
1， 2
1， 2
3
（1. State Key Laboratory of Climate System Prediction and Risk Management/Key Laboratory of Meteorological Disaster， Ministry of
Education/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters， Nanjing University
of Information Science and Technology， Nanjing 210044， Jiangsu， China；
2. School of Atmospheric Sciences， Nanjing University of Information Science and Technology， Nanjing 210044， Jiangsu， China；
3. China Meteorological Administration Training Centre， Beijing 100081， China；
4. Xinhe County Meteorological Bureau，Xinjiang Uygur Autonomous Region， Aksu 842100， Xinjiang， China）

Abstract： Based on daily precipitation gridded data from CN05. 1 ground observation data， the monthly NCEP/
NCAR reanalysis data and sea surface temperature （SST） data from the Japan Meteorological Agency （JMA）
spanning 1961 to 2021， this study uncovers the synergistic influence of the North Pacific and North Atlantic SST
on the interannual anomalies of regionally consistent anomaly patterns in Xinjiang during winter. The findings ob‐
tained from the analysis are presented as follows： （1） Winter precipitation in Xinjiang is predominantly concen‐
trated in the north of the Tianshan Mountains and Kashgar， and EOF analysis identifies three main interannual
anomalous modes， namely regionally consistent anomaly， north-south antiphase anomaly and tripolar anomaly
patterns. A shift from low to high precipitation occurred around 1987， with a significant increase in interannual
variability post-2000.（2） This study identifies the key circulation systems and three transport pathways of cold
air and water vapor facilitating increased interannual winter precipitation in Xinjiang. These include the Polar
east of Novaya Zemlya-Western Siberia-Aral Sea-Northwest and northern Xinjiang northerly cold air and water
vapor path， the tropical and subtropical Atlantic-Mediterranean-Black Sea-Caspian Sea-Xinjiang westerly water
vapor paths and the equatorial Indian Ocean-Arabian Sea-Red Sea-Persian Gulf-Southern Caspian Sea-Xinjiang
southwestern water vapor path.（3） The “relay” mechanism by which North Pacific and North Atlantic SST influ‐
encing the interannual anomalies of winter precipitation in Xinjiang is described. From pre-spring to pre-autumn，
Rossby wave energy excited by the SSTA like a Pacific Decadal Oscillation （“+PDO” -like） Sea Surface Temper‐
ature Anomalies （SST Anomalies， SSTA） propagates eastward from the North Pacific Ocean over the North At‐
lantic， triggering corresponding atmospheric teleconnection wave trains. The North Atlantic SST， along with the
atmospheric anomalies’ signals， drives its SSTA toward the “+” “-”， and “+” tripolar pattern. In winter， the
North Atlantic tripolar SSTA releases its stored energy， exciting a longitudinal tripolar anomalous wave train
（North Atlantic Oscillation with negative phase in the lower layers） and two downstream energy branches. The
northeastern branch contributes to the development of a positive Scandinavian Pattern （SCA）， while the south‐
eastern branch promotes an anticyclonic circulation from North Africa to the northern part of the Arabian Sea，
fostering the development of a upper-level weak temperate jet stream and a strong subtropical jet stream. These
meteorological conditions converge warm and cold air currents in Xinjiang， particularly in its northwestern re‐
gions， leading to an increase in precipitation levels. The precursor “+PDO” -like SSTA can be an interannual pre‐
dictive signal for winter precipitation surpluses in Xinjiang.
Key words： winter precipitation in Xinjiang， China； interannual anomaly； atmospheric teleconnection； North
Pacific SST； North Atlantic SST