CLWD-375: China's lake water clarity dataset from VIIRS 375-m observations (2012–2025)

The processing framework organizes the long-term water clarity dataset (2012-2025) into monthly files stored in the NetCDF-4 format, enabling internal compression to optimize storage. The product contains a monthly aggregation projected onto a uniform grid, distinguishing it from raw swath data. Each NetCDF file adheres to the naming convention SNPP_VIIRS_ChinaLakes_ZSD_MONTHLY_yyyy_mm-fv1.0.nc, where "yyyy" and "mm" denote the year and month, respectively. Inside each file, the water clarity is stored in the variable Zsd (Secchi Disk Depth), accompanied by pixel-aligned 2D coordinate arrays for latitude and longitude. Missing data is flagged with a specific fill value (−32767). To ensure interoperability and adherence to FAIR principles, the dataset strictly follows the Climate and Forecast (CF) metadata conventions. Key variable attributes include the standard name, units (m), and valid data ranges. Furthermore, comprehensive global attributes are embedded in each file to document the data lineage, including the institution (Nanjing Institute of Geography and Limnology, CAS), dataset creator, spatial resolution (375 m), and processing timestamp. The spatial coverage is defined by the bounding box attributes (spatial_lat_min/max, spatial_lon_min/max) calculated dynamically for the region.