Light Transfers Through a Koch Shape Cloud

Journal Article · 02 September 2024 · Geophysical Research Letters

DOI: https://doi.org/10.1029/2024GL110469 · OSTI ID:2439309

Ren, Tong  ^[1]; Yang, Ping  ^[1]; Huang, Xianglei  ^[2]; Iwabuchi, Hironobu  ^[3]

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1. Department of Atmospheric Sciences Texas A&,M University College Station TX USA
2. Department of Climate and Space Sciences and Engineering University of Michigan Ann Arbor MI USA
3. Center for Atmospheric and Oceanic Studies Graduate School of Science Tohoku University Sendai Japan

Abstract Modeling radiative transfer in a 3D cloudy atmosphere is critical to climate projections. A recently developed fast 3D radiation parameterization scheme gains some success in quantifying horizontal radiative transfer through cloud sides using cloud area fraction. Based on 3D Monte Carlo simulations of radiative transfer through an idealized single‐layer cloud with Koch‐shaped fractal geometry edges, here we show that radiative energy transport through cloud sides correlates more significantly with cloud area fraction than with cloud perimeter length. The results exemplify the importance of accounting for the horizontal radiative energy exchanges between cloud‐free and cloudy regions with cloud area fraction. Results from additional sensitivity simulations show that increased cloud vertical extent often enhances cloud‐side sunlight leak more significantly than cloud‐side sunlight interception. At low sun elevations, cloud‐side sunlight interception is enhanced more than cloud‐side sunlight leak does with the increase of cloud mass.

• Sponsoring Organization: USDOE
• Grant/Contract Number: SC0022117
• OSTI ID: 2439309
• Journal Information: Geophysical Research Letters, Journal Name: Geophysical Research Letters Journal Issue: 17 Vol. 51; ISSN 0094-8276
• Publisher: American Geophysical Union (AGU)Copyright Statement
• Country of Publication: United States
• Language: English