Evaluation of Turbulent Flux Parameterizations over a Continental Glacier on the Tibetan Plateau

Abstract. A lack of observations of turbulent fluxes over continental glaciers limits our understanding of the mechanisms that control glacier variations and associated water resource changes across the Tibetan Plateau (TP). Here, we present the first comprehensive analysis of turbulent flux characteristics and a systematic evaluation of turbulent flux methods for a continental glacier on the TP, using eddy covariance observations from the Dunde Glacier (May–October, 2023). The Dunde Glacier persistently lost energy through latent heat flux (mean LE: −10.34 W m⁻²) and gained energy via sensible heat flux (mean H: 6.93 W m⁻²), with pronounced seasonal and diurnal variability. On the basis of these measured data, we tested five turbulent flux methods for the Dunde Glacier, including those derived from katabatic flow models, simplified Monin–Obukhov similarity theory without stability corrections, Monin–Obukhov similarity theory with stability corrections using two different bulk Richardson numbers, and the Monin–Obukhov similarity theory with universal stability functions. Among all schemes, the Monin–Obukhov similarity theory with universal stability functions achieved the highest accuracy for both H and LE at different timescales. We further evaluated the performance of these parameterizations in energy and mass balance modeling. Our results show that the recalibrated turbulent flux parameterizations are an effective approach for improving the accuracy of modelled glacier energy and mass balance, and that the Monin–Obukhov similarity theory with universal stability functions yielded the best simulation performance for modelled glacier mass balance. We also found that the Dunde Glacier experienced a sharp increase in H and reversal in LE during a humid heatwave event, shifting from a negative total turbulent flux under the mean climate condition to positive values during the extreme event. However, none of the turbulent flux methods fully captured the high values that occurred during the extreme weather and climate event, indicating that there is currently an underestimation of the contribution of turbulent fluxes to glacier melt energy. These findings advance our knowledge of turbulent fluxes for continental glaciers on the TP and provide important guidance for the improvement of glacier models.