Inland lake temperature initialization via coupled cycling with atmospheric data assimilation

Abstract. Application of lake models coupled within earth-system prediction models, especially for predictions from days to weeks, requires accurate initialization temperatures. Commonly used methods initialize temperatures include interpolation global sea-surface temperature (SST) analyses inland lakes, daily satellite-based observations, or model-based reanalyses. However, each these have limitations in capturing the temporal characteristics (e.g., effects anomalously warm cold weather) all lakes a geographic region and/or during extended cloudy periods. An alternative lake-initialization method was developed which uses two-way-coupled cycling small-lake model an hourly data assimilation system weather model. The simulated were compared with other estimates satellite and situ observations interpolated-SST multi-month period 2021. initialization, now applied two operational US NOAA found decrease errors surface as much 5–10 K vs. about 1–2 available observations.