平流层风场的火箭观测及其与模式风场的比较

Rocket Sounding Observations of Stratospheric Winds in Kwajalein Island(8°N,167°E)and Their Comparisons with HWM07 and CIRA86

美国西北研究机构（NWRA：NorthWest Research Associates）发布了1963-1992年期间在Kwajalein岛礁（8°N,167°E）上共计1862次火箭探测的平流层风场和温度剖面.本文选取测量较为连续的1969-1972年期间共计345个风场剖面来研究平流层月平均风场及其两年变化、年变化和半年变化的特征.同时与目前应用较为广泛的风场模式HWM07（Horizontal Wind Model：2007）和CIRA86（COSPAR International Reference Atmosphere：1986）进行了比较.火箭测量的4年逐月平均纬向风在夏季为西向风,并在8月41km处达到最大值45ms-1;在冬季变为东向风,并在3月57km处达到最大值47ms-1.全年的经向风在60km以下基本上是北向风且风速低于10ms-1.纬向风在20~35km之间以两年变化为主,振幅在10~17ms-1之间;在45~55km之间以半年变化为主,振幅是16~25 ms-1之间;在5km以上以年变化为主,振幅在16~25 ms-1之间.测量风场与HMW07相比,HWM07的西向风在7月46km处达到最大值38ms-1,东向风在2月60km处达到最大值37ms-1,均小于测量风场的峰值.测量风场与CIRA86相比,CIRA86的西向风在7月49km处达到最大值36ms-1,东向风在3月60km处达到最大值43ms-1,仍小于测量风场的峰值.测量风速稍大于模式风速的可能原因之一是测量风场包含了背景风场和各种波动成分,而模式风场是气候学平均的结果;此外,HWM07和CIRA86虽然包含了不少探空火箭数据,但并没有包含在Kwajalein岛礁的测量资料.

Mean winds in the altitude range of 20-60 km,which were derived from rocket sounding in Kwajalein Island（8°N,167°E）are analyzed.The wind data covered the period of 1969-1972,which was selected from 1963-1992.The quasibiennial variation,annual variation and semi-annual variation have been studied and compared with Horizontal Wind Model 2007（HWM07）and COSPAR International Reference Atmosphere 1986（CIRA86）.The summer westward winds reached a peak value of 45ms-1 in August at 41 km.The winter eastward winds reached apeak value of 47ms-1 in March at 57 km.Below60km,the meridional wind was the northward in general,with the wind speed was less than 10ms-1.In the altitude range of20-35 km,the zonal winds showed a clear quasi-biennial variation,with the amplitude in the range of 10-17ms-1.In the altitude range of 45-55 km,the zonal winds showed a clear semi-annual variation,with the amplitude in the range of 16-25ms-1.Above 55 km,the zonal winds showed a clear annual variation,with the amplitude in the range of 16-25 ms-1.These observed features were compared with HWM07 and CIRA86.HWM07 westward winds reached a peak of 38ms-1 in July at 47 km.HWM07eastward winds reached a peak value of 47ms-1 in February at 66 km.The maximum of HWM07 eastward winds was less than the peak value of the observed winds.This might be the fact that the observed winds include the background winds and the various waves,while empirical winds are average results of climatology.In addition,although HWM07 and CIRA86contain a lot of rocket sounding data,they do not include the observed wind dates in the Kwajalein Island.