Earth's Climate Variability over 7 Years from CrIS Brightness Temperature, OMPS Ozone, CarbonTracker CO2, and MERRA-2

The CLARREO mission has been established by NASA’s Langley Research Center to establish benchmark measurements using traceable international standards (SI) through various independent paths. Wielicki et al. (2013) showed that the time to detect trends in the atmosphere depends on several factors, including the magnitude of the trend, the natural variability, temporal auto-correlation, and measurement error. The CLARREO mission has proposed sensors which emphasize absolute accuracy in order to minimize the time to detect climate trends. However, the natural variability and auto-correlation of the atmosphere can be characterized with existing observations which have similar spectral coverage and resolution. The nominal mission lifetime needed to establish a baseline measurement for the infrared benchmark is five years. The NASA Suomi-NPP satellite recently completed a seven-year record of observations covering the period May 2012 – April 2019 in the early afternoon orbit. On the Suomi-NPP satellite, the Cross-track InfaRed Sounder (CrIS) measures outgoing radiance in the spectral range 3.5 to 15 microns with a resolving power of 1000. Coincident with the nadir CrIS infrared radiance observations, profiles of ozone are available from the Ozone Mapping Profiler Suite (OMPS) limb profiler sensor also on the Suomi-NPP satellite. The coincident CrIS and OMPS data provides a unique dataset for the characterization of the correlation of observed brightness temperature and ozone on zonal, monthly space and time scales. Cross-comparisons will be made with CrIS brightness temperature, OMPS ozone, MERRA-2, and CarbonTracker CO2, along with model data cross-comparisons. The objective of the current study is to compute an estimate of the inter-annual variability and auto-correlation of outgoing spectrally resolved infrared emission from operational polar orbiting hyperspectral infrared sensors in sun synchronous orbits.