Distribution and trends of the cold-point tropopause over China from 1979 to 2014 based on radiosonde dataset
Distribution and trends of the cold-point tropopause over China from 1979 to 2014 based on radiosonde dataset
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DOI：
10.1016/j.atmosres.2017.04.008
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发表时间：
2017-09
影响因子：
5.5
通讯作者：
Chaoli Tang;Xuebin Li;Jianyu Li;Congming Dai;L. Deng;Heli Wei
中科院分区：
文献类型：
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作者：
Chaoli Tang;Xuebin Li;Jianyu Li;Congming Dai;L. Deng;Heli Wei
利用1979-2014年中国77个测站的探空资料，分析了冷点对流层顶（CPT）的变化趋势。将我国18°N ~ 53°N的纬度区域以5°为间隔划分为7个纬度带，将18°N ~ 53°N、75°E ~ 135°E的空间区域划分为27个5° × 10°网格。然后通过每个纬度和经度箱中的所有可用样本计算CPT高度（H-CPT）和CPT温度（T-CPT）的年平均值。利用最小二乘回归方法，发现H-CPT以273 m/decade的速率增加，而T-CPT在中国的总体冷却速率为-0.70 K/decade。分析了各纬度带H-CPT和T-CPT的变化趋势和纬度分布。不同纬度分布特征的H-CPT差异在逐年减小，T-CPT差异在逐年扩大。H-CPT在28°N-53°N纬度范围内呈上升趋势，变化率为正;在18°N-28°N纬度范围内呈下降趋势，变化率为负。T-CPT的变化率在所有纬度带均为负值。最后，首次给出了各空间单元H-CPT和T-CPT长期趋势的非均匀纬向和经向分布。
The variation trends of the cold-point tropopause (CPT) are presented using radiosonde observations from 77 stations over China during 1979–2014. The latitude regions over China from 18°N to 53°N are divided into 7 latitude zones with every 5° intervals, and the spatial areas of 18°N–53°N, 75°E–135°E are divided into 27 lattices with 5° × 10° grids. The annual-mean values of height-of-CPT (H-CPT) and temperature-of-CPT (T-CPT) are then calculated by all the available samples within each latitude and longitude bin. By using the least squares regression method, it is found that the H-CPT increases with the rate of 273 m/decade, and overall the significant cooling rate of − 0.70 K/decade for the T-CPT over the whole of China. Then, the trends and latitude distribution of H-CPT and T-CPT for each latitude zone are analyzed. The difference of H-CPT among latitude distribution characteristic is reducing year by year, and the difference of T-CPT is enlarging. The H-CPT displays a rising trend between 28°N–53°N latitude region with the positive change rates, and it has decline trend between 18°N–28°N latitude region with the negative change rates. The change rates of T-CPT are negative values for all latitude zones. At last, the nonuniform latitudinal and longitudinal distribution of long-term trends of H-CPT and T-CPT are first presented for each spatial cell.