Diurnal variations in middle-atmospheric water vapor by ground-based microwave radiometry
Diurnal variations in middle-atmospheric water vapor by ground-based microwave radiometry
复制标题
通过地面微波辐射测量中层大气水蒸气的日变化
DOI：
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
N. Kämpfer
中科院分区：
文献类型：
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作者：
D. Scheiben;A. Schanz;Brigitte Tschanz;N. Kämpfer
抽象的。在本文中，我们比较了在瑞士伯尔尼附近的阿尔卑斯山地区由两个地基微波辐射计测量的中层大气水汽的日变化。观测数据集还比较了化学气候模式WACCM的数据。由于日变化较小，通常小于1%，因此需要较长时间段的平均值。因此，采取了两个各为五个月的时间段，即12月至4月和6月至10月进行比较。观测资料的日变化在振幅和相位上相互吻合。线性相关系数范围从平流层上部的0.8到中层上部的0.5。在仪器灵敏度范围内的所有压力水平下，观察到的昼夜变化都很显着。与WACCM的观测结果比较发现，12月至4月的日变化周期与模式的一致性要比6月至10月的好。在WACCM中，两个时间段的日变化幅度随高度增加，但在观测中保持近似恒定在0.05 ppm。WACCM资料用于分离导致伯尔尼上空中层大气水汽日变化的过程。0.1 hPa以下为纬向平流，0.1 ~ 0.02 hPa为垂直平流，0.02 hPa以上为光化学。纬向平流的贡献很小。在WACCM数据中看到的最高日变化的水蒸气被发现在中层顶区域在6月至10月的时间段内，日振幅为0.2 ppm（约5%的相对单位）。
Abstract. In this paper, we compare the diurnal variations in middle-atmospheric water vapor as measured by two ground-based microwave radiometers in the Alpine region near Bern, Switzerland. The observational data set is also compared to data from the chemistry–climate model WACCM. Due to the small diurnal variations of usually less than 1%, averages over extended time periods are required. Therefore, two time periods of five months each, December to April and June to October, were taken for the comparison. The diurnal variations from the observational data agree well with each other in amplitude and phase. The linear correlation coefficients range from 0.8 in the upper stratosphere to 0.5 in the upper mesosphere. The observed diurnal variability is significant at all pressure levels within the sensitivity of the instruments. Comparing our observations with WACCM, we find that the agreement of the phase of the diurnal cycle between observations and model is better from December to April than from June to October. The amplitudes of the diurnal variations for both time periods increase with altitude in WACCM, but remain approximately constant at 0.05 ppm in the observations. The WACCM data are used to separate the processes that lead to diurnal variations in middle-atmospheric water vapor above Bern. The dominating processes were found to be meridional advection below 0.1 hPa, vertical advection between 0.1 and 0.02 hPa and (photo-)chemistry above 0.02 hPa. The contribution of zonal advection is small. The highest diurnal variations in water vapor as seen in the WACCM data are found in the mesopause region during the time period from June to October with diurnal amplitudes of 0.2 ppm (approximately 5% in relative units).
首次利用地面微波光谱法检测极地中层水蒸气中的潮汐行为
影响因子：
6.3
作者：
K. Hallgren;P. Hartogh
通讯作者：
P. Hartogh