Retrievals of aerosol optical depth over the western North Atlantic Ocean during ACTIVATE

Aerosol optical depth was retrieved from two airborne remote sensing instruments, the Research Scanning Polarimeter (RSP) and Second Generation High Spectral Resolution Lidar (HSRL-2), during the National Aeronautics and Space Administration (NASA) Aerosol Cloud meTeorology Interactions oVer the wes...

Full description

Bibliographic Details
Published in:Atmospheric Measurement Techniques
Main Authors: L. W. Siu, J. S. Schlosser, D. Painemal, B. Cairns, M. A. Fenn, R. A. Ferrare, J. W. Hair, C. A. Hostetler, L. Li, M. M. Kleb, A. J. Scarino, T. J. Shingler, A. Sorooshian, S. A. Stamnes, X. Zeng
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2024
Subjects:
Environmental engineering
TA170-171
Earthwork. Foundations
TA715-787
North Atlantic
Online Access:https://doi.org/10.5194/amt-17-2739-2024
https://doaj.org/article/328aea0935fe45c8a75b91858af91ff3
Description
Summary:Aerosol optical depth was retrieved from two airborne remote sensing instruments, the Research Scanning Polarimeter (RSP) and Second Generation High Spectral Resolution Lidar (HSRL-2), during the National Aeronautics and Space Administration (NASA) Aerosol Cloud meTeorology Interactions oVer the western ATlantic Experiment (ACTIVATE). The field campaign offers a unique opportunity to evaluate an extensive 3-year dataset under a wide range of meteorological conditions from two instruments on the same platform. However, a long-standing issue in atmospheric field studies is that there is a lack of reference datasets for properly validating field measurements and estimating their uncertainties. Here we address this issue by using the triple collocation method, in which a third collocated satellite dataset from the Moderate Resolution Imaging Spectroradiometer (MODIS) is introduced for comparison. HSRL-2 is found to provide a more accurate retrieval than RSP over the study region. The error standard deviation of HSRL-2 with respect to the ground truth is 0.027. Moreover, this approach enables us to develop a simple, yet efficient, quality control criterion for RSP data. The physical reasons for the differences in two retrievals are determined to be cloud contamination, aerosols near the surface, multiple aerosol layers, absorbing aerosols, non-spherical aerosols, and simplified retrieval assumptions. These results demonstrate the pathway for optimal aerosol retrievals by combining information from both lidars and polarimeters for future airborne and satellite missions.

Similar Items