Improved parameterization of snow albedo in Noah coupled with Weather Research and Forecasting

Improved parameterization of snow albedo in Noah coupled with Weather Research and Forecasting: Applicability to snow estimates for the Tibetan Plateau

Liu, Lian (Chinese Academy of Sciences; Land-Atmosphere Interaction and Its Climatic Effects Group)
Ma, Yaoming (Chinese Academy of Sciences; CAS Center for Excellence in Tibetan Plateau Earth Sciences; University of Chinese Academy of Sciences)
Menenti, M. (TU Delft Optical and Laser Remote Sensing; Chinese Academy of Sciences)
Su, Rongmingzhu (Chinese Academy of Sciences; University of Chinese Academy of Sciences)
Yao, Nan (Chinese Academy of Sciences; University of Chinese Academy of Sciences)
Ma, Weiqiang (Chinese Academy of Sciences; CAS Center for Excellence in Tibetan Plateau Earth Sciences; University of Chinese Academy of Sciences)

2021

Snow albedo is important to the land surface energy balance and to the water cycle. During snowfall and subsequent snowmelt, snow albedo is usually parameterized as functions of snow-related variables in land surface models. However, the default snow albedo scheme in the widely used Noah land surface model shows evident shortcomings in land-atmosphere interaction estimates during snow events on the Tibetan Plateau. Here, we demonstrate that our improved snow albedo scheme performs well after including snow depth as an additional factor. By coupling the Weather Research and Forecasting (WRF) and Noah models, this study comprehensively evaluates the performance of the improved snow albedo scheme in simulating eight snow events on the Tibetan Plateau. The modeling results are compared with WRF run with the default Noah scheme and in situ observations. The improved snow albedo scheme significantly outperforms the default Noah scheme in relation to air temperature, albedo and sensible heat flux estimates by alleviating cold bias estimates, albedo overestimates and sensible heat flux underestimates, respectively. This in turn contributes to more accurate reproductions of snow event evolution. The averaged root mean square error (RMSE) relative reductions (and relative increase in correlation coefficients) for air temperature, albedo, sensible heat flux and snow depth reach 27% (5%), 32% (69%), 13% (17%) and 21% (108%), respectively. These results demonstrate the strong potential of our improved snow albedo parameterization scheme for snow event simulations on the Tibetan Plateau. Our study provides a theoretical reference for researchers committed to further improving the snow albedo parameterization scheme.

http://resolver.tudelft.nl/uuid:e0a241ab-06e8-4c14-b937-4c98c48893ed

https://doi.org/10.5194/hess-25-4967-2021

1027-5606

Hydrology and Earth System Sciences, 25 (9), 4967-4981

Institutional Repository

journal article

© 2021 Lian Liu, Yaoming Ma, M. Menenti, Rongmingzhu Su, Nan Yao, Weiqiang Ma