Monte Carlo Study of UAV-Measurable Albedo over Arctic Sea Ice
In anticipation that unmanned aerial vehicles (UAVs) will have a useful role in atmospheric energy budget studies over sea ice, a Monte Carlo model is used in this study to investigate three-dimensional radiative transfer over a highly inhomogeneous surface albedo involving open water, sea ice, and...
Published in: | Journal of Atmospheric and Oceanic Technology |
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Main Authors: | , , |
Language: | unknown |
Published: |
2021
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Subjects: | |
Online Access: | http://www.osti.gov/servlets/purl/1541861 https://www.osti.gov/biblio/1541861 https://doi.org/10.1175/jtech-d-17-0066.1 |
Summary: | In anticipation that unmanned aerial vehicles (UAVs) will have a useful role in atmospheric energy budget studies over sea ice, a Monte Carlo model is used in this study to investigate three-dimensional radiative transfer over a highly inhomogeneous surface albedo involving open water, sea ice, and melt ponds. The model simulates the spatial variability in 550-nm downwelling irradiance and albedo that a UAV would measure above this surface and underneath an optically thick, horizontally homogeneous cloud. At flight altitudes higher than 100 m above the surface, an airborne radiometer will sample irradiances that are greatly smoothed horizontally as a result of photon multiple reflection. If one is interested in sampling the local energy budget contrasts between specific surface types, then the UAV must fly at a low altitude, typically within 20 m of the surface. Spatial upwelling irradiance variability in larger open water features, on the order of 1000 m wide, will remain apparent as high as 500 m above the surface. To fully investigate the impact of surface feature variability on the energy budget of the lower troposphere iceāocean system, a UAV needs to fly at a variety of altitudes to determine how individual features contribute to the area-average albedo. |
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