Non-Gaussian Distributions of TOA SW Flux as Observed by MISR and CERES

Thumbnail Image

Files

JGR Atmospheres - 2022 - Lee - Non‐Gaussian Distributions of TOA SW Flux as Observed by MISR and CERES.pdf (6.65 MB)

Links to Files

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2022JD036636

Permanent Link

https://doi.org/10.1029/2022JD036636
 http://hdl.handle.net/11603/25206

Collections

UMBC Joint Center for Earth Systems Technology (JCET)
UMBC Faculty Collection

Author/Creator

Author/Creator ORCID

https://orcid.org/0000-0001-9814-9855

Date

2022-06-30

Type of Work

journal articles
postprints
Text

Department

Program

Citation of Original Publication

Lee, J. N., & Wu, D. L. (2022). Non-Gaussian Distributions of TOA SW Flux as Observed by MISR and CERES. Journal of Geophysical Research: Atmospheres, 127, e2022JD036636. https://doi.org/10.1029/2022JD036636

Rights

This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.
Public Domain Mark 1.0

Subjects

Abstract

The Top of Atmosphere (TOA) shortwave (SW) flux, converted from Terra Multi-angle Imaging SpectroRadiometer (MISR) narrow band albedos, is compared with that measured from Clouds and the Earth's Radiant Energy System (CERES). We describe the probability density function (PDF) of the monthly TOA SW flux and how the statistical third moment, skewness, can impact the quantification of the flux. The PDF of the SW flux is not normally distributed but positively skewed. In both sets of observations, the near-global (80 S–80 N) median value of the SW flux is ∼3 W/m2 less than the mean value, due to the positive skewness of the distribution. The near-global mean TOA SW flux converted from MISR is about 7 W/m2 (∼7%) less than CERES measured flux during the last two decades. Surprisingly, a hemispheric asymmetry exists with TOA SW observations from the Terra platform. SH reflects 3.92 and 1.15 W/m2 more mean SW flux than NH, from MISR and CERES Single Scanner Footprint products, respectively. We can infer that the offsetting by morning clouds in the SH is greater than the effect of hemispheric imbalance of SW flux caused by different land masses in two hemispheres. While the characteristics of the two SW fluxes broadly agree with each other, differences in the regional PDF from two different SW fluxes are substantial over high cloud regions and high altitude regions. Our analysis shows that some parts of the different skewness from the two measurements may be attributed to the different calibration of the radiance anisotropy over high cloud scenes.