Variability of polar stratospheric water vapor observed by ILAS
Variability of polar stratospheric water vapor observed by ILAS
复制标题
ILAS观测到的极地平流层水汽变化
DOI：
10.1029/2001jd001164
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发表时间：
2002
影响因子：
--
通讯作者：
T. Sugita
中科院分区：
文献类型：
--
作者：
L. Pan;W. Randel;S. Massie;H. Kanzawa;Y. Sasano;H. Nakajima;T. Yokota;T. Sugita
[1]我们提出了一个分析极地平流层水蒸气的测量的改进临边大气光谱仪（ILAS）机载高级地球观测卫星（ADEOS）。用同期位涡场将涡旋与涡外空气分离，研究了水汽的变化。从ILAS测量的整体水汽分布在定性上与UARS参考大气（涵盖1992-1999年）的水汽气候学一致，时空变化与已知的平流层环流是一致的。在平流层下部（400-800 K位温或15-30 km），ILAS和卤素掩星实验（HALOE）等效纬度纬向平均值之间的定量比较显示在5%以内的一致性。然而，在平流层上部（800-1800 K位温或30-45公里），与8年（1992-1999年）UARS气候学和HALOE数据相比，ILAS数据有10%至20%的高偏差。ILAS的数据涵盖1996年11月至1997年6月的时间段，是在北极极地平流层异常寒冷的冬春期间测量的。ILAS的水汽数据表明，北极涡旋在春季比UARS气候学中看到的更加孤立和持久。今年北极涡旋的空间和时间范围与南极涡旋非常相似。同一测量期的哈洛埃数据支持这一特点。使用轨迹模型，我们表明1997年春季的北半球涡旋与该十年中的其他年份相比明显更加孤立，这解释了ILAS观察到的北极涡旋内高水蒸气的异常限制。
[1] We present an analysis of polar stratospheric water vapor from measurements of the Improved Limb Atmospheric Spectrometer (ILAS) onboard the Advanced Earth Observing Satellite (ADEOS). The variability of water vapor is examined using contemporaneous potential vorticity fields to separate the vortex from the extravortex air. The overall water vapor distribution from the ILAS measurements agrees qualitatively with the water vapor climatology in the UARS reference atmosphere (covering 1992–1999), and the space-time variability is consistent with the known stratospheric circulation. Quantitatively, comparisons between ILAS and Halogen Occultation Experiment (HALOE) equivalent latitude zonal means show agreement to within 5% in the lower stratosphere (400–800 K potential temperature or 15–30 km). In the upper stratosphere (800–1800 K potential temperature or 30–45 km), however, ILAS data have a 10% to 20% high bias compared to the 8-year (1992–1999) UARS climatology and to HALOE data for the same time period. The ILAS data, covering the time period November 1996 to June 1997, were measured during a winter-spring period when the Arctic polar stratosphere was anomalously cold. The ILAS water vapor data suggest an Arctic vortex that is more isolated and persistent in the spring than that seen in the UARS climatology. The spatial and temporal extent of the Arctic vortex this year was very similar to that of the Antarctic vortex. This feature is supported by HALOE data for the same measurement period. Using a trajectory model, we show that the NH vortex in spring 1997 was significantly more isolated compared to other years in the decade, and this explains the unusual confinement of high water vapor within the Arctic vortex observed by ILAS.