Validation of the Icesat-2 Lake Water Level Product

The ICESat-2 ATL13 product provides measurements of inland water surface height or water level. However, it has been shown that such water level observations are subject to noticeable uncertainties and need to be carefully handled for reliable water level determination. This paper presents an approach to detect outliers in the ATL13 product so that accurate outcome can be achieved. Lake Huron and Lake Superior of the Great Lakes are selected as the study areas. The extracted water levels from ATL13 over a period of four years are validated by using field observations at the closest NOAA hydrological stations. This work demonstrates the critical need on outlier removal and the capability of the ATL13 data. A bias of 9-10 cm is found in the ATL13 product. Such an uncertainty is positively related to the frozen precipitation, but mostly independent from the laser beam intensity and data acquisition time.