Global Surface Blue-sky Albedo Climatology Dataset from 20-year MODIS Products

Surface albedo plays a critical role in climate, hydrological, and biogeochemical modeling and weather forecasting. It is usually assigned in models by adjusting climatology data or look-up-maps between albedo and land cover types, however, there are large albedo differences among model predictions partly due to the albedo climatology uncertainty. Therefore, precisely mapping surface albedo climatology globally is necessary to better parameterize environmental systems. The current albedo climatology is mainly produced by the long-term satellite albedo products, while the data quality (accuracy, spatiotemporal resolution, and spatial coverage) is highly affected by the restrictions of large historical data volume and high computational requirement. We generated a new global surface blue-sky albedo climatology dataset from 20-year MODIS products from the Google Earth Engine (GEE). The 500m global surface blue-sky daily albedo climatology dataset is generated, and it follows the basic MODIS product format and employed the sinusoidal projection. After reprojection and aggregation, the global Climate Modeling Grid (CMG) albedo climatology datasets at 0.05° and 0.5° are available at (DOI). All of the published datasets include historical and snow-free blue-sky albedo climatology data. For the application conveniences, the land cover climatology of MODIS product (MCD12Q1) is also generated and attached in the CMG files. The International Geosphere-Biosphere Programme (IGBP) and PFT classification results of MCD12Q1 from 2001 to 2019 were reprojected and aggregated to 0.05° and 0.5° by find mode in each aggregation group. In order to check the heterogeneity of the land cover climatology, the percentage of the dominant type in each aggregation group was also calculated.