Title: Stratospheric Aerosol Measurements From a Compact Satellite Instrument
Presenting Author: Matthew DeLand
Organization: Science Systems and Applications, Inc. (SSAI)
Co-Author(s): Peter Colarco (NASA/GSFC) Matthew Kowalewski (NASA/GSFC) Luis Ramos-Izquierdo (NASA/GSFC) Mary Grace Kalnay (Loft Orbital)

Abstract:
Observations of aerosol distributions in the Earth's stratosphere represent a key input for Earth system models that must characterize atmospheric composition and radiative heating in order to project their chemistry and climate effects. Significant perturbations due to impulsive events such as volcanic eruptions and smoke plumes from large wildfires can have considerable economic and climate consequences. Characterization of the stratospheric aerosol layer thus needs good vertical resolution to capture variations in horizontal transport, dense spatial sampling to capture local structure, and regular temporal sampling to follow the evolution of aerosol injections at a specific location. We have developed a compact satellite instrument called Aerosol Radiometer for Global Observations of the Stratosphere (ARGOS) to meet these requirements. ARGOS measures scattered light from the Earth's limb in 8 directions simultaneously to enable global spatial coverage from a Sun-synchronous orbit. Closely spaced (15 minutes apart) measurements of along-track locations with different scattering angles will help characterize the aerosol phase function. Observations at two near-IR wavelengths (870 nm, 1550 nm) provide good vertical range and information about particle size distribution. All measurements are captured on a single focal plane that provides < 1 km vertical resolution. ARGOS observations will be compatible with the current OMPS Limb Profiler extinction retrieval algorithm to enable creation of Level 2 data products. ARGOS is scheduled for space flight demonstration in Spring 2024 as a hosted payload supported by Loft Orbital. This approach offers significant advantages for small instruments in terms of available size, mass, power, communications, mission operations, and flight opportunities. ARGOS instrument integration and performance testing is in progress. We will present the status of this work.