Assessment of MODIS TEB calibration performance using deep convective clouds

The DCC core is one of the coldest and most consistent targets. When viewed from space, the measurements over DCC have minimal impact from water vapor and aerosols. DCC technique can also be used for assessing the calibration and product stability for infrared thermal emissive bands (TEB). In this work, the stabilities from the years 2003 to 2019 are analyzed for both Terra and Aqua LWIR bands. Terra band 30 shows the largest change rate of 0.196 K/yr, and the total change since 2003 is approximately 3 K. Terra bands 27 and 29 and Aqua band 29 also show 0.03-0.05 K/yr changes, and the other bands exhibit stable trending. The Terra-Aqua difference for each LWIR band is analyzed. Band 30 shows the largest difference and largest change between Terra and Aqua. In general, for both Terra and Aqua, the LWIR bands show good and stable detector uniformity. However, the mirror side differences are affected by their anomalies such as the Terra safe mode in February 2016 and the Aqua formatter reset in January 2018. The impact of the Terra safe mode on the mirror side difference are generally larger for PV LWIR bands 27-30. After the safe mode, the mirror side difference jumped and then decreased. Before the formatter reset, the mirror side difference of Aqua PV LWIR bands is relatively larger than after the event. Aqua mirror side differences are stable and are smaller after the formatter reset. The formatter reset impact on the band averaged measurement is insignificant.