极地研究 ›› 2018, Vol. 30 ›› Issue (2): 140-153.DOI: 10.13679/j.jdyj.20170026

• 研究论文 • 上一篇    下一篇

南极特拉诺瓦湾下降风特征

孙启振1,2, 张占海1,3, 丁卓铭2, 沈辉2, 张林2, 孟上2   

  1. 1. 物理海洋教育部重点实验室, 中国海洋大学, 山东 青岛 266100
    2. 国家海洋环境预报中心, 极地环境研究预报室, 北京 100081
    3. 国家海洋局极地科学重点实验室, 中国极地研究中心, 上海 200136
  • 收稿日期:2017-07-26 修回日期:2017-08-31 出版日期:2018-06-30 发布日期:2018-06-30
  • 通讯作者: 孙启振
  • 基金资助:

    国家自然科学基金(41206185, 41076128)、国家留学基金(201504180004)资助

Characteristics of katabatic winds in Terra Nova Bay, Antarctica

Sun Qizhen1,2, Zhang Zhanhai1,3, Ding Zhuoming2, Shen Hui2, Zhang Lin2, Meng Shang2   

  • Received:2017-07-26 Revised:2017-08-31 Online:2018-06-30 Published:2018-06-30
  • Contact: Qi-Zhen SUN
  • Supported by:

    National Natural Science Foundation of China;National Natural Science Foundation of China

摘要:

南极罗斯海特拉诺瓦湾(Terra Nova Bay)是强下降风汇集区之一。采用高分辨率南极中尺度预报系统
(Antarctic Mesoscale Prediction System, AMPS)资料和特拉诺瓦湾难言岛Manuela 自动气象站实测数据, 分
析了特拉诺瓦湾及其附近地区的下降风特征。AMPS 对难言岛地区风速和气温有较好的模拟能力, 但风向
比实测值偏西约30°。难言岛地区风速从1 月开始迅速增大, 4—9 月风力平均为8 级以上。难言岛夏季1 月
份的风速变化滞后气温变化约3 h; 冬季7 月份风向稳定为西至西南。特拉诺瓦湾及其附近地区下降风来自
西岸海拔较高的冰盖, 其风向的空间分布特征基本几乎不随季节而变化。下降风风速有显著的季节演变特
征, 11 月至次年1 月较小, 3—9 月风速较大。特拉诺瓦湾西岸等几处冰川地带在冬季是强风汇集区, 难言岛
处于Reeves 冰川下降风汇集区中。该汇集区上边界和南北两侧均有清晰的分界线, 风速较强区从地面延伸
至650—800 m 高处, 风速最大值距离地面高度约为50—200 m。强下降风气流受难言岛地形阻挡, 风速有
所减弱, 气流越过难言岛之后, 风速再次加强。特拉诺瓦湾地区下降风流动过程中近地面气团位势温度变化
幅度很小, 表明下降风在从内陆高原到沿岸地区的流动是干绝热过程。

关键词: 南极, 特拉诺瓦湾, 难言岛, 下降风

Abstract:

Terra Nova Bay (TNB), Antarctica, is one of the confluence zones where strong katabatic winds are intense.
In this paper, data from the high-resolution Antarctic mesoscale prediction system (AMPS) and automatic
weather station (AWS) Manuela on Inexpressible Island in TNB are used to analyze the characteristics
of katabatic winds in these areas. The AMPS shows good capability in simulating wind speed and air temperature
at Inexpressible Island; however, the simulated wind direction is about 30° further westward than
measured. The wind speed at Inexpressible Island increases rapidly from January and it is maintained at a
high level during April–September. Data from the Manuela AWS indicate the strongest winds lag the lowest
temperatures by about 3 h in January, and in winter, the measured wind direction is mostly west-southwest.
Katabatic winds in TNB and the surrounding area are derived from the higher ice sheet to the west, and the
spatial distribution of the wind direction rarely changes with season. The wind speed shows considerable
seasonal variation; winds are generally a breeze during November–January, before increasing during
March–September. In winter, katabatic winds form confluence zones at several glaciers near the coast of
TNB, and Inexpressible Island is affected by katabatic winds from the Reeves Glacier. Boundaries are clear
in the upper, northern, and southern sides of the katabatic winds areas of the Reeves Glacier. Strong katabatic
winds extend from the surface to 650–800 m above ground level (AGL), and the core of the maximum
wind speed is located at about 50–200 m AGL. Strong katabatic winds can be weakened because of the terrain
of Inexpressible Island. The surface potential temperature differs little from the inland plateau to the
coastal area near TNB, indicating a dry adiabatic process within the march of the katabatic winds in these
areas.

Key words: Antarctica, Terra Nova Bay, Inexpressible Island, katabatic winds