Corrected TOGA COARE Sounding Humidity Data: Impact on Diagnosed Properties of Convection and Climate over the Warm Pool
Corrected TOGA COARE Sounding Humidity Data: Impact on Diagnosed Properties of Convection and Climate over the Warm Pool
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修正后的 TOGA COARE 探空湿度数据：对暖池上空对流和气候诊断特性的影响
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
Junhong Wang
中科院分区：
文献类型：
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作者：
P. Ciesielski;Richard H. Johnson;P. Haertel;Junhong Wang
本文报道了热带海洋全球大气(TOGA)海-气耦合响应试验(COARE)高空探测数据集的湿度修正及其对暖池上空对流和气候诊断特征的影响。在COARE期间，从29个使用Vaisala制造的系统的站点和13个使用VIZ制造的系统的站点收集了探测数据。最近的一份出版物记录了Vaisala站点的湿度误差的特征和纠正它们的程序。这项研究通过描述VIZ湿度误差的性质及其校正方案来扩展这项工作。这种改正在对流层低层最大，通常会增加Vaisala探测站的水汽，减少VIZ探测站的水汽。利用校正后的湿度数据，对COARE期间的对流特征给出了一个非常不同的观点。例如，一个简单的云模式的应用表明，对流质量通量的峰值从未经修正的约88N移动到修正后的赤道以南，这与诊断的垂直运动和观测到的降雨量更符合。Vaisala站和VIZ站的平均对流可用势能之差(CAPE)在700J·kg2~(-1)以上，经修正后，两者都在1300J·kg2~(-1)左右，与暖池海温场基本一致。这些结果表明，在使用湿度校正数据的模式模拟中，对流的强度和位置将显著不同，再分析产品在再现COARE期间观测到的降雨时遇到的困难可能是由于探空仪的湿度偏差造成的。经湿度校正的数据似乎对预算得出的降雨量和辐射加热率估计数有有利影响，因此，订正估计数与来自独立来源的估计数更好地吻合。
This study reports on the humidity corrections in the Tropical Ocean Global Atmosphere (TOGA) Coupled Ocean‐Atmosphere Response Experiment (COARE) upper-air sounding dataset and their impact on diagnosed properties of convection and climate over the warm pool. During COARE, sounding data were collected from 29 sites with Vaisala-manufactured systems and 13 sites with VIZ-manufactured systems. A recent publication has documented the characteristics of the humidity errors at the Vaisala sites and a procedure to correct them. This study extends that work by describing the nature of the VIZ humidity errors and their correction scheme. The corrections, which are largest in lower-tropospheric levels, generally increase the moisture in the Vaisala sondes and decrease it in the VIZ sondes. Use of the corrected humidity data gives a much different perspective on the characteristics of convection during COARE. For example, application of a simple cloud model shows that the peak in convective mass flux shifts from about 88N with the uncorrected data to just south of the equator with corrected data, which agrees better with the diagnosed vertical motion and observed rainfall. Also, with uncorrected data the difference in mean convective available potential energy (CAPE) between Vaisala and VIZ sites is over 700 J kg21; with the correction, both CAPEs are around ;1300 J kg21, which is consistent with a generally uniform warm pool SST field. These results suggest that the intensity and location of convection would differ significantly in model simulations with humidity-corrected data, and that the difficulties which the reanalysis products had in reproducing the observed rainfall during COARE may be due to the sonde humidity biases. The humidity-corrected data appear to have a beneficial impact on budget-derived estimates of rainfall and radiative heating rate, such that revised estimates show better agreement with those from independent sources.