Validation of In Situ Size-Resolved Composition Model from the 2023 AEROMMA Airborne Field Mission Against Ground-Based and Remote Sensing Aerosol Optical Measurements
HAN N. HUYNH, Adam Ahern, Charles Brock, Ming Lyu, Samuel Taylor, Xiaoli Shen, Justin Jacquot, Daniel Cziczo, Alison Piasecki, Ann M. Middlebrook, Sarah Albertin, Daniel Murphy, Glenn Diskin, Charles K. Gatebe, Johnathan Hair, CU-CIRES/NOAA CSL
Abstract Number: 302
Working Group: Aerosol Processes and Properties in Changing Environments in the Anthropocene
Abstract
One of the primary objectives of the Atmospheric Emissions and Reactions Observed from Megacities to Marine Areas (AEROMMA) 2023 field mission was to measure aerosol and trace gas properties to help evaluate and improve the satellite products of the Tropospheric Emissions: Monitoring of pollution (TEMPO) instrument. There was a comprehensive suite of aerosol instruments on the NASA DC-8 aircraft, including measurements of aerosol size distribution (3 nm–50 μm), aerosol chemical composition (from both single particle and aerosol mass spectrometers), and aerosol optical measurements over the UV-Vis wavelengths. The DC-8 aircraft also performed multiple vertical profiles that provided important points of comparison between the in situ and remote sensing measurements including satellite retrievals, such as direct comparison of column-integrated aerosol optical depth (AOD) and aerosol layer height.
We will give a brief overview of our complete aerosol profile constructed from combining the in situ aerosol microphysical, chemical, and optical measurements with a special focus on East Coast urban flights over Toronto, New York, and Chicago. The size-resolved aerosol composition and vertical profile provides key atmospheric features of these urban cities, including the wildfire smoke events in July-August 2023. Including sensitivity analyses of collocation of the following three modes of aerosol measurements, the in situ observation-derived AODs were validated against AOD values derived from both (1) ground-based measurements (e.g., Aerosol Robotic Network, AERONET) and (2) remote sensing measurements onboard a NASA G-V aircraft with a down-looking, high-spectral-resolution lidar (HSRL) that was operated in patterns in the vicinity. In addition, these active remote sensing measurements at ambient RH conditions were compared to the extinction vertical profile at ambient RH derived from our dry, in situ aerosol measurements onboard the DC-8. The AEROMMA in situ composition and size distribution data can provide direct validation of the accuracy of and underlying assumptions of aerosol retrievals from AERONET and HSRL. Overall, our observation-based aerosol profile yielded AOD values within 10% of reported HSRL AODs – a remarkably close agreement in part due to their excellent collocation. Because of the unavailability of many close AERONET sites to DC-8 spiral locations, AERONET AODs are on average about 2x higher than both observation-based AODs and HSRL AODs. The results from this ongoing study will provide the bases for future validation against aerosol data products from the TEMPO satellite as they become available.