Surface energy budget over the South Pole and turbulent heat fluxes as a function of an empirical bulk Richardson number

[1] Routine radiation and meteorological data at South Pole Station are used to investigate historical discrepancies of up to 50 W m2 in the monthly mean surface energy budget and to investigate the behavior of turbulent heat fluxes under stable atmospheric temperature conditions. The seasonal cycle...

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Bibliographic Details
Main Authors: Michael S. Town, Von P. Walden
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Subjects:
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.483.1039
http://www.webpages.uidaho.edu/~vonw/pubs/townandwalden_2009.pdf
Description
Summary:[1] Routine radiation and meteorological data at South Pole Station are used to investigate historical discrepancies of up to 50 W m2 in the monthly mean surface energy budget and to investigate the behavior of turbulent heat fluxes under stable atmospheric temperature conditions. The seasonal cycles of monthly mean net radiation and turbulent heat fluxes are approximately equal, with a difference of 40 W m2 between summer and winter, while the seasonal cycle of subsurface heat fluxes is only a few W m2. For an 8-month period (the winter of 2001), we calculate two estimates of turbulent heat fluxes, one from Monin-Obukhov (MO) similarity theory and one as the residual of the surface energy budget (i.e., subsurface heat fluxes minus net radiation, where all fluxes toward the snow surface are positive). The turbulent fluxes from MO theory agree well with the residual of the energy budget under lapse conditions. However, under stable conditions MO theory underestimates turbulent fluxes by approximately 40–60%. The relationship between turbulent heat fluxes as a residual of the energy budget, temperature inversion strength, and wind shear as a function of the bulk Richardson number (Rib) is examined under stable conditions (i.e., positive Rib). The Rib