Publications

Toth, TD; Zhang, JL; Campbell, JR; Reid, JS; Vaughan, MA (2016). Temporal variability of aerosol optical thickness vertical distribution observed from CALIOP. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 121(15), 9117-9139.

Abstract
Temporal variability in the vertical distribution of aerosol optical thickness (AOT) derived from the 0.532 mu m aerosol extinction coefficient is described using Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) observations over 8.5years (June 2006 to December 2014). Temporal variability of CALIOP column-integrated AOT is largely consistent with total column AOT trends from several passive satellite sensors, such as the Moderate Resolution Imaging Spectroradiometer, Multiangle Imaging Spectroradiometer, and the Sea-viewing Wide Field-of-view Sensor. Globally, a 0.0002 AOT per year positive trend in deseasonalized CALIOP total column AOT for daytime conditions is attributed to corresponding changes in near-surface (i.e., 0.0-0.5km or 0.5-1.0km above ground level (agl)) aerosol particle loading, while a -0.0006 AOT per year trend during nighttime is attributed to elevated (i.e., 1.0-2.0km or >2.0km agl) aerosols. Regionally, increasing daytime CALIOP AOTs are found over Southern Africa and India, mostly due to changes in aerosol loading at the 1.0-2.0km and 0.0-0.5km agl layers, respectively. Decreasing daytime CALIOP AOTs are observed over Northern Africa, Eastern U.S., and South America (due mostly to elevated aerosol loading), while the negative CALIOP AOT trends found over Eastern China, Europe, and Western U.S. are due mostly to aerosol layers nearer the surface. To our knowledge, this study is the first to provide both a globally comprehensive estimation of the temporal variation in aerosol vertical distribution and an insight into passive sensor column AOT trends in the vertical domain.

DOI:
10.1002/2015JD024668

ISSN:
2169-897X