大气科学2016，Vol.40Issue(4)：817-830,14.DOI:10.3878/j.issn.1006-9895.1508.15189
北半球中高纬度低频振荡对2012/2013年冬季中国东北极端低温事件的影响
Impacts of the Low-Frequency Oscillation over the Extra-tropics of the Northern Hemisphere on the Extreme Low Temperature Event in Northeast China in the Winter of 2012/2013
摘要
Abstract
AbstractUsing daily data of NCEP/DOE reanalysis II and the temperature data collected at conventional observation stations of National Meteorological Information Center, the characteristics of the low-frequency oscillation (LFO) of the <br> regionally averaged temperature during the extreme low temperature event in Northeast China in the winter of 2012/2013 is analyzed. Changes in the spatial configuration of low-frequency circulation systems in the mid- and lower troposphere in the extratropics of the Northern Hemisphere and their linkage with cold air activities are analyzed. Furthermore, the propagation character of the low-frequency circulation systems and their impacts on temperature changes are also investigated. Results show that: (1) the regionally averaged temperature in Northeast China in the winter of 2012/2013 exhibits a strong 10–30-day oscillation feature, which is accompanied by a significant 30–60-day oscillation and closely related to actual temperature drops. (2) for the 10–30-day oscillation, the phase 7 (phase 3) corresponds to maximum decrease (increase) in temperature over Northeast China; Northeast China is under control of the strong northerly (southerly) air current between the low-frequency high (low) pressure system around Lake Baikal and low-frequency low (high) pressure system nearby the Sea of Japan at 500 hPa; meanwhile, East China from the north to the South China Sea is mainly controlled by low-frequency northerly (southerly) wind at 850 hPa, which strengthens (suppresses) the circulation system of East Asian winter monsoon. As a result, Northeast China undergoes a cooling (warming) process. With such a spatial configuration and evolution of low-frequency circulation systems in the mid- and lower troposphere, Northeast China is affected by strong (or stronger) cold airmass that follows an easterly and/or northerly path and extremely low temperature event happens. (3) A low-frequency wave train at 500 hPa propagates along the path of Urals–Baikal Lake–Northeast China–western Pacific. It is the circulation system that actuates the LFO of East Asian winter monsoon and the extreme low temperature event in Northeast China.关键词
东北地区/极端低温/低频环流系统Key words
Northeast China/Extremely low temperature event/Low-frequency circulation system分类
天文与地球科学引用本文复制引用
苗青,巩远发,邓锐捷,魏挪巍..北半球中高纬度低频振荡对2012/2013年冬季中国东北极端低温事件的影响[J].大气科学,2016,40(4):817-830,14.基金项目
国家自然科学基金资助项目41275080，公益性行业（气象）科研专项GYHY201306022@@@@Funded by National Natural Science Foundation of China (Grant 41275080), China Meteorological Administration Special Public Welfare Research Fund (Grant GYHY201306022) （Grant 41275080）
