Diurnal drift correction in the NESDIS/STAR MSU/AMSU atmospheric temperature climate data record
Diurnal drift correction in the NESDIS/STAR MSU/AMSU atmospheric temperature climate data record
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NESDIS/STAR MSU/AMSU 大气温度气候数据记录中的日漂移校正
DOI：
10.1117/12.824459
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发表时间：
2009
影响因子：
4.9
通讯作者：
Wenhui Wang
中科院分区：
文献类型：
--
作者：
C. Zou;Wenhui Wang
NESDIS/卫星应用和研究中心(STAR)一直在重新处理和重新校准来自微波探测单元(MSU)和高级微波探测单元(AMSU)的观测数据，以生成大气温度气候数据记录。为了从数据集中获得可靠的大气温度趋势，必须从时间序列中去除轨道漂移引起的日漂移误差。这种调整对于日漂移影响较大的陆地上MSU/AMSU中对流层温度产品尤为重要。在这项研究中，我们将遥感系统(RSS)开发的日异常应用于MSU/AMSU大气温度CDR，并研究了这种校正如何影响陆地上的趋势和卫星间偏差。引入了一个比例因子来乘以RSS日异常，以考虑数据集中的不确定性。结果表明，日漂移对海洋对流层中层温度变化趋势的影响可以忽略不计，这与前人的研究结果一致。然而，土地上的趋势对比例系数的大小非常敏感。最终的比例因子是通过最小化陆地上的卫星间温差来确定的。与此比例因子对应的28年(1979年-2006年)MSUT2合并时间序列的趋势值在全球陆地上为0.193 K/十年，在全球海洋上为0.180 K/十年。全球平均T2趋势为0.183 K/十年。
NESDIS/Center for Satellite Applications and Research (STAR) has been reprocessing and recalibrating observations from the Microwave Sounding Unit (MSU) and Advanced Microwave Sounding Unit (AMSU) to generate atmospheric temperature climate data record (CDR). To obtain reliable atmospheric temperature trends from the dataset, diurnal drift errors due to orbital drift must be removed from the time series. This adjustment is especially important for the MSU/AMSU mid-tropospheric temperature product over land where diurnal-drift effect is large. In this study, we applied the diurnal anomalies developed by the Remote Sensing Systems (RSS) to the STAR MSU/AMSU atmospheric temperatures CDR and examined how the correction affects the trend and intersatellite biases over land. A scaling factor was introduced to multiply the RSS diurnal anomalies to account for uncertainties in the dataset. The results show that the diurnal drift has negligible effect on the mid-tropospheric temperature trends over oceans, which is consistent with previous investigations. However, the trend over land is very sensitive to the magnitude of the scaling factor. The final scaling factor was determined by minimizing intersatellite temperature differences over land. The trend values corresponding to such a scaling factor for the 28-year (1979-2006) merged MSU T2 time series are 0.193 K/Decade over the global land and 0.180 K/Decade over the global ocean. The global mean T2 trend is 0.183 K/decade.