Seasonal variations of the near surfacelayer parameters over the Antarctic ice sheet in Princess Elizabeth Land,East Antarctica

Analysis of sensible heat flux(Qh),latent heat flux(Qe),Richardson number(Ri),bulk transport coefficient(Cd) and katabatic winds are presented by using the meteorological data in the near surface layer from an automatic weather station(AWS) in Princess Elizabeth Land,East Antarctica ice sheet and the data of corresponding period at Zhongshan station in 2002.It shows that annual mean air temperature at LGB69 is-25.6°C,which is 16.4°C lower than that at Zhongshan,where the elevation is lower and located on the coast.The temperature lapse rate is about 1.0°C/110 m for the initial from coast to inland.The turbulence heat flux at LGB69 displays obvious seasonal variations with the average sensible heat flux-17.9 W/m2 and latent heat flux-0.9 W/m2.The intensity(Qh Qe) of coolling source is-18.8 W/m2 meaning the snow surface layer obtains heat from atmosphere.The near surface atmosphere is near-neutral stratified with bulk transport coefficients(Cd) around 2.8×10-3,and it is near constant when the wind speed higher than 8 m/s.The speed and the frequency of easterly Katabatic winds at LGB69 were higher than that at Zhongshan Station.     

北冰洋78°N冰站近地层参数的观测研究

利用2003年8月22日-9月3日中国北极科学考察队在北冰洋78°N浮冰站获得的近地层观测资料,采用整体输送法对北冰洋浮冰近地层特征参数进行了分析研究。结果表明,在考察期间,雪面吸收的净辐射仅为3.6 W/m2,其中以感热和潜热向大气输送的能量分别占52%和31%,向海冰深层传导的热量很少;近中性层结条件下的平均拖曳系数Cdn为1.16×10-3,略小于75°N北冰洋浮冰上近中性层结的Cdn。与1999年75°N附近冰站观测结果的对比表明,当海冰密度及冰站所在浮冰的尺度不同时,海冰与大气相互作用的热力学和动力学过程的差异显著,在研究北冰洋地区海/冰/气相互作用对气候过程影响时,应考虑这一问题。     

Analyses of structure of planetary boundary layer in ice camp over Arctic ocean

The vertical structure of Planetary boundary layer over Arctic floating ice is presented by using about 50 atmospheric profiles and relevant data sounded at an ice station over Arctic Ocean from 22 August to 3 September,2003.It shows that the height of the convective boundary layer in day is greater than that of the stability boundary layer in night.The boundary layer can be described as vertical structures of stability,instability and multipling The interaction between relative warm and wet down draft air from up level and cool air of surface layer is significant,which causes stronger wind shear,temperature and humidity inversion with typical wind shear of 10 m/s/100 m,intensity of temperature inversion of 8 ℃/100 m.While the larger pack ice is broken by such process,new ice free area in the high latitudes of arctic ocean.The interactions between air/ice/water are enhanced.The fact helps to understanding characteristics of atmospheric boundary layer and its effect in Arctic floating ice region.     

南极海冰北界涛动指数及其与我国夏季天气气候的关系

南极海冰的变化和全球大气环流关系密切。南极各区海冰的不同变化, 对南北半球大气环流有着不同的影响。文中基于对南极海冰变化的客观分区, 定义了南极海冰北界涛动指数 (ASEOI), 并结合中央气象台提供的南方涛动指数、北半球500 hPa和100 hPa高度场资料以及我国160站降水、温度资料, 利用诊断分析方法, 对ASEOI与我国夏季天气气候的关系进行了研究。研究表明:ASEOI对我国长江中下游降水及全国大部分地区温度具有指示意义。若前一年10月ASEOI偏低, 则当年7月我国长江中下游降水偏多, 引发洪涝灾害的可能性很大; 温度场上, 我国北方气温偏高, 南方气温偏低, 而高温往往伴随着少雨, 这无疑会加剧华北本就严重的旱情。     

Spatial-temporal characters of Antarctic sea ice variation

Using sea ice concentration dataset covering the period of 1968-2002 obtained from the Hadley Center of UK, this paper investigates characters of Antarctic sea ice variations .The finding demonstrates that the change of mean sea-ice extent is almost consistent with that of sea-ice area, so sea-ice extent can be chosen to go on this research. The maximum and the minimum of Antarctic sea ice appear in September and February respectively. The maximum and the maximal variation of sea ice appear in Weddell Sea and Ross Sea, while the minimum and the minimal variation of sea-ice appear in Antarctic Peninsula. In recent 35 years, as a whole, Antarctic sea ice decreased distinctly. Moreover, there are 5 subdivision characteristic regions considering their different variations. Hereinto, the sea-ice extent of Weddell Sea and Ross Sea regions extends and area increases, while the sea-ice extent of the other three regions contracts and area decreases. They are all of obvious 2-4 years and 5-7 years significant oscillation periods. It is of significance for further understanding the sea-ice-air interaction in Antarctica region and discussing the relationship between sea-ice variation and atmospheric circulation.     

南极半岛地区气温与南极海冰涛动、ENSO的联系

使用南极半岛Orcadas等台站的气温多年观测资料 ,分析了南极半岛气温和周围海冰以及ENSO的初步联系。结果表明 ,南极半岛地区的气温变化可以反映南极海冰涛动的变化特征 :气温距平和南极半岛附近海冰距平存在密切的负相关 ,和罗斯海外围区域的海冰距平存在正相关关系 ,能够较好地反映出南极半岛气温与南极海冰涛动以及ENSO之间的紧密联系。当南极半岛地区气温偏低 (高 )时 ,南极半岛周围海冰偏多 (少 ) ,罗斯海外围海冰偏少 (多 ) ,赤道中东太平洋海温偏高 (低 ) ,可能出现ElNino(LaNina)。另外 ,南极半岛当年 1 0月的气温距平对预测次年 1月的Nino3区海温异常具有重要参考价值     

北极斯瓦尔巴德地区近地层大气观测研究II.湍流场特征

利用“中国科学探险协会2002年北极科学探险考察”期间在北极朗伊尔宾地区获得的大气风温微气象脉动资料,讨论了该地区近地层湍流能谱、湍流方差、感热通量、动量通量、温度结构参数以及动量整体输送系数等的分布规律,给出了这一极端环境区夏季近地层微气象场的基本结构,分析了北极地区极昼期间陆地下垫面地-气之间能量交换,丰富了人们对该地区近地层湍流输送过程的深入理解。     

北极苔原和海冰地区边界层物理过程的观测研究

国家自然科学基金重点项目“北极苔原和海冰地区边界层物理过程的观测研究”在下列方面取得了较大进展：     

南极气候与大气环境研究

南极气候与大气环境研究本研究是国家科技攻关项目（８５－９０５－２－５），周秀骥院士为项目主持人。南极地区，包括南极大陆、亚南极岛屿和环绕南极大陆的南大洋，是全球大气研究计划（ＧＡＲＰ）、世界气候研究计划（ＷＣＲＰ）及国际岩石圈－生物圈计划（ＩＧＢＰ）...     

南极和邻近地区温度的时空变化特征

对南极和邻近地区1957～1993年气温的空间分布特征、时间变化趋势及多年振荡特征的研究表明,南极地区的短期气候变化在时间、空间上都是多样的,南极不是对全球温室效应响应最强烈的地区,其温度变化趋势与全球平均变化有较大差异.这种变化和差异很难简单地用全球温室效应来解释.