在挑战中虎虎生威

有异于连续数年的暖冬,新年里京城连降几场大雪,气温异常寒冷,整个北半球也概莫如此。置身全球变暖的大背景下,公众的疑问在愈演愈烈的严寒中也不断“升温”：频频光顾的寒潮和暴雪是不是全球变暖的终结者？是不是意味着全球气候已走进拐点,步入变冷新阶段？     

臭氧层空洞也是帮凶

地球西风循环移动加快了全球变暖步伐。为什么南半球西风循环幅度要高于北半球？因为这是人类活动的另一个后果——南极上空的臭氧层空洞——正在改变哈德里环流和加速西风循环。     

北半球高温难耐 南半球遇罕见寒冷

俄罗斯人是应付严寒天气的行家,然而2010年夏季前所未有的高温,却让“扛寒高手”们陷入一片恐慌和混乱。受到高温炙烤的不只俄罗斯,进入6-7月份后整个北半球都陷入了高温恐慌。同时,本来气候温暖的南半球却比往年冷得多。地球为何北热南冷？     

对抛射体偏离发射面的探讨

在地面附近的抛射体偏离发射面的情况是与发射仰角α和发射声、的纬度λ有关系。     

悉尼遭遇红色沙尘暴

沙尘暴是春天多发的灾害天气。当我们北半球迎来秋天的时候．南半球的澳大利亚正好迎来了他们的春天。由于地表植被近年来遭到破坏。澳大利亚首都悉尼在2009年9月下旬迎来了一轮汹涌的沙尘暴。由于澳大利亚的土壤大多为红色,袭击悉尼的沙尘暴也呈现出可怕的红色。     

远古升温促进使动物迁徙

科学家最近发现，从古新世到始新世曾经出现全球升温，促使最早的灵长类动物开始了长途迁徙。动物们只花了不到两万年时间就从亚洲来到北美，几乎扩散到整个北半球。     

菲利普岛的童话之旅

2009年10月底。在飞行了14个小时后,我终于来到了距离北京万里之遥的澳大利亚南部城市墨尔本。从北半球寒冷的深秋过渡到南半球温暖的仲春．也从此开始了一次令我难忘终生的自然之旅。     

Role of Ferrel cell in daily variability of Northern Hemisphere Annular Mode

The Northern Hemisphere Annular Mode(NAM) represents the zonally symmetric planetary-scale atmospheric mass fluctuations between middle and high latitudes, whose variations have shown a large impact on other components of the climate system. Previous studies have indicated that the NAM is correlated with the Ferrel cell in their monthly or longer timescale variability.However, there have been few studies investigating their connections at daily timescale, though daily variability of NAM has been suggested to be an important component and has significant implication for weather forecast. The results from this study demonstrate that variability of the Ferrel cell leads that of the NAM by about 1–2 days. This statistically identified temporal phase difference between NAM and Ferrel cell variability can be elucidated by meridional mass redistribution. Intensified(weakened)Ferrel cell causes anomalously smaller(larger) poleward mass transport from the middle to the high latitudes,resulting in an increase(a decrease) in mass in the middle latitudes and a decrease(an increase) in the high latitudes.As a consequence, anomalously higher(lower) poleward pressure gradient forms and the NAM subsequently shifts to a positive(negative) phase at a time lag of 1–2 days. The findings here would augment the existing knowledge for better understanding the connection between the Ferrel Cell and the NAM, and may provide skillful information for improving NAM as well as daily scale weather prediction.     

昆士兰暖意正浓

岁末年初,正是放下手中的工作,与朋友和家人寻个好去处度假的时候!而南半球的澳大利亚昆士兰正伴着融融暖意,无论你是亲子派、美食家还是烟火迷,暂别北半球的寒冬定能令你容颜焕发,神采飞扬地在大洋彼岸独享一片专属的阳光。     

变暖？变冷？给个理由先

全球变暖,如今是地球人都知道的事情了。不过,让人有点尴尬的是,哥本哈根气候峰会刚开过,北半球就应声集体遭遇几十年难遇的极寒严冬。用英国《泰晤士报》的话来说,“芝加哥人躲避着能冻死人的严寒,巴黎阳光普照但冷得像西伯利亚,意大利冰雪覆盖……”