An investigation into the impacts of crop type and acreage changes on surface albedo
Abstract
Accurate surface albedo calculations are relied upon for a large number of applications, ranging from remote sensing to weather-related numerical modeling efforts. While most of these surface albedos stay consistent or have a predictable annual variation, human caused changes in agricultural systems, such as crop selection resulting in mono-crop coverage over large areas, can have a significant impact on inter- and intra-annual albedo variations. Failing to account for these specific crop impacts to albedo variation, can lead to uncertainties for down-stream calculations that rely upon albedo, such as satellite remote sensing of atmospheric properties and regional radiative forcing resulting from agriculture's impacts on albedo.
Utilizing the spaceborne Moderate Resolution Imaging Spectroradiometer (MODIS) based Bidirectional Reflectance Distribution Function (BRDF) product we investigate the albedo variation between croplands featuring large, contiguous areas of 52 crops commonly grown in the United States, along with 15 other land cover types, over a four year period ending in 2018. Through this study we calculate the expected black and white sky albedo through the entire growing season for each crop, separated into nine distinct climate regions, directly examining the impacts of the continuously changing acreages at a nationwide scale. Additionally, we have employed this dataset to evaluate the use of the normalized difference vegetation index (NDVI) as an approximation of surface albedo, giving us insight into the reliability of using this proxy across multiple-wavelengths, absent the underlying crop information.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.A11H2730S
- Keywords:
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- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0319 Cloud optics;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0360 Radiation: transmission and scattering;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 4275 Remote sensing and electromagnetic processes;
- OCEANOGRAPHY: GENERAL