Diurnal Black-Sky Surface Albedo Parameterization of Snow
| Autor: | Emmihenna Jääskeläinen, Terhikki Manninen, Aku Riihelä |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Surface (mathematics)
Atmospheric Science 010504 meteorology & atmospheric sciences media_common.quotation_subject Albedo 010502 geochemistry & geophysics Snow Atmospheric sciences 01 natural sciences 13. Climate action Sky Environmental science 0105 earth and related environmental sciences media_common |
| Zdroj: | Journal of Applied Meteorology and Climatology. 59:1415-1428 |
| ISSN: | 1558-8432 1558-8424 |
| Popis: | Surface albedo, the fraction of incoming solar radiation reflected hemispherically by the surface, is an essential climate variable (ECV) directly related to the energy budget of Earth. The presence and properties of snow cover alter surface albedo significantly, with variability in temporal scales reaching from seasonal to diurnal. The diurnal variation of snow albedo is typically parameterized with the solar zenith angle, but it cannot take into account asymmetry with respect to midday. Using the solar azimuth angle instead is suggested, since especially in the melting season the snow albedo varies highly asymmetrically during the day. To derive a general time- and latitude-independent formula, the azimuth angle values are normalized. Baseline Surface Radiation Network data are used to derive an empirical formula for the diurnal variation of snow black-sky surface albedo. The overall accuracy is on the order of 0.02, and the relative accuracy is about 3%. |
| Databáze: | OpenAIRE |
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