Name
Evaluation of reanalysis air temperature products for stream temperature modeling using statistical models and the hybrid air2stream model
Description
Stream temperature is a key indicator of physical water quality and habitat suitability for salmonids and other cold-water species, and models are increasingly being used in aquatic resource management. Stream temperature models vary in complexity from process-based energy balance models to empirical relations with air temperature, but a common input data requirement is air temperature. The objective of this study was to evaluate reanalysis air temperature products for use as input to two types of models for at-a-site predictions, one based on statistical relations between stream temperature and air temperature, and the other the air2stream hybrid model. Air temperature time series were downscaled from the European Atmospheric Reanalysis 5 (ERA5) and the North American Regional Reanalysis (NARR) gridded products and compared to air temperatures interpolated from weather station data. The ERA5 temperatures more accurately matched the station-based interpolation product than did the NARR temperatures. When used as predictors in statistical models, the reanalysis products performed competitively with and sometimes superior to the station-based interpolation. Evaluation of the air2stream model is in progress, and a final step will be to evaluate model predictions of stream temperature response to events such as the summer 2021 heat dome event in British Columbia.