南极中山站夏季下降风数值模拟个例研究

发布时间：2018-07-11 13:55

  本文选题：南极 + 下降风　； 参考：《海洋学报》2016年03期

【摘要】：南极内陆地面辐射冷却产生的近表层冷空气,沿高原斜坡向下流动而形成下降风,其分布形态决定了南极大陆近表层风场的主要特征。我国南极中山站全年均受下降风的强烈影响。夏季晴天时,中山站的下降风一般在傍晚开始出现,风速在午夜达到极值,在次日中午之前逐渐减弱,风速有显著的日循环特征。本文选取南极中山站2010年1月的夏季下降风个例,使用常规地面气象观测资料和Polar WRF极地大气数值模式进行了分析研究。结果表明:中山站夏季夜间晴天出现偏东向的下降风时,近地面风速变化趋势与地面气温呈负相关,相关系数为-0.91。数值模拟发现,中山站下降风在距地面高度约100~150m之间时风速最大,约为15~21m/s。在下降风发生时,近地层大气存在逆温现象。下降风较强时,近地层逆温也较强,逆温层厚度约为200~300m,逆温强度约为4~6℃。在地面摩擦的作用下,中山站近地面下降风风向为东南,随着高度的增加,风向逆时针偏转,最终趋于与地形等高线平行。没有太阳直接辐射时,南极大陆地区存在持续的逆温层,逆温层的出现加强了下降风气流,随着逆温的增强,大风区逐渐西移,且面积不断增加。在夏季太阳辐射造成的逆温消失的短暂时间内,逆温时产生的下降风尚不能完全消失,由此形成了较稳定的风向空间分布特征。
[Abstract]:The near-surface cold air produced by radiation cooling on the surface of the Antarctic interior flows down the slope of the plateau and forms a descending wind, which determines the main characteristics of the near-surface wind field in the Antarctic continent. China's Zhongshan Station in Antarctica is strongly affected by the downwind all year round. When summer is sunny, the downwind at Zhongshan Station usually appears in the evening, the wind speed reaches its maximum at midnight, and gradually weakens before noon of the next day. The wind speed has obvious daily circulation characteristics. In this paper, the case of summer downwind in Zhongshan Station, Antarctica, in January 2010 is selected, and the conventional surface meteorological observation data and Polar WRF polar atmospheric numerical model are used to carry out the analysis and study. The results show that there is a negative correlation between the trend of the near surface wind speed and the surface air temperature, and the correlation coefficient is -0.91when there is eastward downwind on sunny days in summer at Zhongshan Station. The numerical simulation shows that the maximum wind speed is 1521m / s when the descending wind is about 100 ~ 150m above the ground height at Zhongshan Station. When the downwind occurs, there is an inverse temperature phenomenon in the near-ground atmosphere. When the downwind is strong, the inversion temperature in the near layer is also strong, the thickness of the inversion layer is about 200 ~ 300m, and the inversion intensity is about 4 ~ 6 鈩，

本文编号：2115419