On the relative stability of CERES reflected shortwave and MISR and MODIS visible radiance measurements during the Terra satellite mission

摘要

Fifteen years of visible, near-infrared, and broadband shortwave radiance measurements from Clouds and the Earth's Radiant Energy System (CERES), Multiangle Imaging Spectroradiometer (MISR), and Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on board NASA's Terra satellite are analyzed in order to assess their long-term relative stability for climate purposes. A regression-based approach between CERES, MODIS, and MISR (An camera only) reflectances is used to calculate the bias between the different reflectances relative to a reference year. When compared to the CERES shortwave broadband reflectance, relative drift between the MISR narrowbands is within 1% decade ~(?1). Compared to the CERES shortwave reflectance, the MODIS narrowband reflectances show a relative drift of less than ?1.33% decade?1. When compared to MISR, the MODIS reflectances show a relative drift of between ?0.36% decade~(?1) and ?2.66% decade~(?1). We show that the CERES Terra SW measurements are stable over the time period relative to CERES Aqua. Using this as evidence that CERES Terra may be absolutely stable, we suggest that the CERES, MISR, and MODIS instruments meet the radiometric stability goals for climate applications set out in Ohring et al. (2005).