Aerosol Retrievals From SPEXone on the NASA PACE Mission: First Results and Validation

Abstract We present the first Spectropolarimeter for Planetary EXploration ‐ one (SPEXone) aerosol retrieval results over land and ocean using the Remote sensing of Trace gas and Aerosol Products algorithm, covering the period 23 February–31 August 2024. We validate the retrieved Aerosol Optical Depth (AOD), Angstrom Exponent (AE), and Single Scattering Albedo (SSA) with AErosol RObotic NETwork (AERONET) data. The validation results show that SPEXone provides products of good quality, with comparable performance over land and ocean. For AOD, the Root‐Mean‐Square Error (RMSE) is 0.053 over land and 0.043 over ocean, while respectively 77% and 75% of the retrievals are within the requirement formulated by the Global Climate Observing System (GCOS). For AE, the RMSE is 0.25 over land and 0.26 over ocean. For SSA, the RMSE is 0.036 over land and 0.036 over ocean, with respectively 69% and 69.4% within the GCOS requirement. After a gap of more than 10 years, this is the first new global Multi‐Angle Polarimeter aerosol dataset.