Moderate Resolution Imaging Spectroradiometer (MODIS) on Aqua has been in operation providing continuous global observations for science research and applications since 2002. The long-term stability of thermal emissive bands (TEBs) of Aqua MODIS was monitored through inter-comparisons with measurements by hyperspectral or multi-spectral infrared sensors or through vicarious monitoring over cold targets such as Dome-C and deep convective clouds. The radiative transfer modeling (RTM)-based simulation models are developed to perform the long-term monitoring of the stability of Aqua MODIS TEBs. Long-term European Centre for Medium-Range Weather Forecasts global atmospheric reanalysis data are used as inputs to the RTM simulation. By confining ocean in low to middle latitudes as the area of interest, the long-term stabilities of Aqua MODIS TEBs are monitored through observation minus background (O-B) brightness temperature (BT) bias between MODIS measurements and simulations from the RTM. In general, the RTM-based O-B analysis shows that the long-term stability of Aqua MODIS TEBs are maintained well. It is shown that Aqua MODIS surface bands are all radiometrically stable with yearly BT bias drifts <0.005 K / year for B20, B22, and B23 and ∼0.01 K / year for B31 and B32. The carbon dioxide (CO2) absorption channels of Aqua MODIS, e.g., B33 to B36, are stable with a BT bias drift <0.005 K / year. It is also found that after accounting for the long-term growth of greenhouse gas N2O, the O-B bias trends for B24 and B25 are quite stable with yearly BT bias drifts around 0.0002 and 0.0055 K / year, respectively. The stabilities of the moisture-sensitive channels B27 to B29 and the ozone channel B30 of Aqua MODIS are also evaluated and the remnant small variations in the O-B bias trending of these channels are further discussed. The RTM-based inter-comparison of MODIS TEB measurements with global atmospheric and climate re-analysis data provides validation of the long-term radiometric stability of Aqua MODIS TEBs. The analysis in this paper also demonstrates that the comparison of well-calibrated MODIS TEB measurements with RTM simulation helps quantify the long-term impacts of global greenhouse gas concentration growth on the BT decreases in the MODIS greenhouse gas-sensitive channels.

中文翻译：

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通过辐射传递模型评估aqua MODIS热发射带的稳定性

自2002年以来，Aqua上的中等分辨率成像光谱仪（MODIS）一直在运行，可为科学研究和应用提供连续的全球观测结果。AquaMODIS的热发射带（TEB）的长期稳定性通过相互比较进行监测，并通过高光谱测量或多光谱红外传感器，或通过对Dome-C和深对流云等冷目标的替代监测。开发基于辐射传递建模（RTM）的仿真模型来执行Aqua MODIS TEB稳定性的长期监控。欧洲中型天气预报长期中心将全球大气再分析数据用作RTM模拟的输入。通过将海洋限制在中低纬度作为关注区域，Aqua MODIS TEB的长期稳定性通过观测减去MODIS测量与RTM模拟之间的背景（OB）亮度温度（BT）偏差进行监控。通常，基于RTM的OB分析表明，Aqua MODIS TEB的长期稳定性得到了很好的维护。结果表明，Aqua MODIS表面带辐射稳定，B20，B22和B23的年BT偏置漂移<0.005 K /年，而B31和B32的BT偏置漂移<0.01 K /年。Aqua MODIS的二氧化碳（CO2）吸收通道（例如B33至B36）稳定，且BT偏差漂移<0.005 K /年。还发现，在考虑了温室气体N2O的长期增长之后，B24和B25的OB偏差趋势非常稳定，年BT偏差分别约为0.0002和0.0055 K /年。还评估了Aqua MODIS的湿度敏感通道B27至B29和臭氧通道B30的稳定性，并进一步讨论了这些通道的OB偏差趋势中的剩余小变化。基于RTM的MODIS TEB测量与全球大气和气候再分析数据之间的比较，验证了Aqua MODIS TEB的长期辐射稳定性。本文的分析还表明，将经过良好校准的MODIS TEB测量值与RTM模拟进行比较有助于量化MODIS温室气体敏感通道中全球温室气体浓度增长对BT降低的长期影响。