Two-decade of monitoring spatio-temporal variation of surface albedo over a large saline lake

• DOI: 10.5194/egusphere-egu2020-1172
• Publication Date: 2020-03-09T12:31:46Z
• Authors: Somayeh Sima; َAmir Darzi
• Keywords: Albedo (alchemy); Moderate-resolution imaging spectroradiometer; Seasonality

<p>Saline lakes play a crucial role in regulating the regional climate, supporting unique biodiversity, and providing diverse range of economic benefits. However, as result growing water withdrawals for human use, most large saline worldwide are desiccating at substantial rate. Water level decline salinity rise affect physico-chemical characteristics including surface albedo. albedo impacts lake color evaporation. Here, we investigate spatio-temporal variation over Lake Urmia, northwest Iran, using MODerate Resolution Imaging Spectroradiometer (MODIS) product (MCD43D) from 2000 to 2019. Satellite-derived shortwave albedos were validated against in-situ data measured an online net-radiometer station on lake. We identified two spatial patterns through Urmia: 1) decreasing trend outer shallow zones toward deep inner parts, 2) higher mean south arm compared north summer. Moreover, varies seasonally with reaches its peak between September October. This is mainly due increased concentration total suspended solids (TSS) phytoplankton (Duanalliea spp.) growth, which accounts red mid-spring early autumn. Results also revealed that concurrent drop since 2000, both lake-averaged seasonal have constantly increased. The affects net absorbed radiation by limits Consequently, emphasize experience significant areal fluctuations seasonally, use constant estimate evaporation heat budget inadequate. Instead, satellite-derived maps encompassing effect depth, TSS, growth can be used confidence. Our findings contribute enhanced water, energy, salt balance models better estimation their albedo. </p><p>Keywords: Surface albedo, MODIS, level, Phytoplankton</p>