Title: Observing Stratospheric Aerosols With ARGOS
Presenting Author: Matthew DeLand
Organization: Science Systems and Applications, Inc.
Co-Author(s): Pete Colarco, Matt Kowalewski, Luis Ramos-Izquierdo, Mary Grace Kalnay

Abstract:
Observations of aerosol distributions in the Earth’s stratosphere represent a key input for Earth system models that must characterize atmospheric heating. Significant heating effects are also observed due to impulsive events such as volcanic eruptions and smoke plumes from large wildfires, which can have considerable economic consequences. These aerosol measurements need 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. All measurements are captured on a single focal plane with an image sensor that provides vertical resolution at a scale of less-than 1 km. Measurements at many along-track locations with different scattering geometry (forward vs. backward) will help characterize the aerosol phase function. Concurrent observations at two near-IR wavelengths (870 nm, 1550 nm) provide good vertical range and additional information about particle size distribution. ARGOS data products 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 Fall 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. The ARGOS instrument has completed environmental testing and prelaunch characterization, and integration onto the spacecraft is in progress.