Modeling Lake Energy Fluxes in the Mackenzie River Basin using Bulk Aerodynamic Mass Transfer Theory

Abstract

Multiple years of micrometeorological and energy flux measurements for four Canadian Shield lakes were used to develop bulk aerodynamic mass transfer coefficients (C _D ) for each lake and for groups of lakes. Transfer coefficients determined from multiple years of data for the two smallest lakes were similar (1.26 x 10 ^-3 and 1.30 x 10 ^-3 ) while that for the largest lake was slightly smaller (1.10 x 10 ^-3 ). The coefficient for the medium-size lake was erroneously high (2.14 x 10 ^-3 ) likely due to generalizations in the calculation of heat storage. No strong relationships were found between the coefficient values and morphometric parameters. The linear regression comparison of measured and modeled daily fluxes using multi-year coefficients gave an average r² of 0.78. The same coefficients performed the best at estimating cumulative latent and sensible heat loss. Absolute percent errors suggest that the multi-year coefficients give acceptable results for small and medium-size lakes only, and that these coefficients cannot be transferred from one lake to another, unless the lakes are similar in size.