On the measurement of the surface energy budget over a land surface during the summer monsoon

Bhat, G. S. ; Arunchandra, S. C. (2008) On the measurement of the surface energy budget over a land surface during the summer monsoon Journal of Earth System Science, 117 (6). pp. 911-923. ISSN 0253-4126

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Official URL: http://www.ias.ac.in/jess/dec2008/jess158.pdf

Related URL: http://dx.doi.org/10.1007/s12040-008-0076-0


The measurement of surface energy balance over a land surface in an open area in Bangalore is reported. Measurements of all variables needed to calculate the surface energy balance on time scales longer than a week are made. Components of radiative fluxes are measured while sensible and latent heat fluxes are based on the bulk method using measurements made at two levels on a micrometeorological tower of 10m height. The bulk flux formulation is verified by comparing its fluxes with direct fluxes using sonic anemometer data sampled at 10Hz. Soil temperature is measured at 4 depths. Data have been continuously collected for over 6 months covering pre-monsoon and monsoon periods during the year 2006. The study first addresses the issue of getting the fluxes accurately. It is shown that water vapour measurements are the most crucial. A bias of 0.25% in relative humidity, which is well above the normal accuracy assumed by the manufacturers but achievable in the field using a combination of laboratory calibration and field intercomparisons, results in about 20W m-2 change in the latent heat flux on the seasonal time scale. When seen on the seasonal time scale, the net longwave radiation is the largest energy loss term at the experimental site. The seasonal variation in the energy sink term is small compared to that in the energy source term.

Item Type:Article
Source:Copyright of this article belongs to Indian Academy of Sciences.
Keywords:Surface Fluxes; Energy Budget; Land Experiment; Summer Monsoon; Atmospheric Sciences; Climate; Experiments
ID Code:2504
Deposited On:08 Oct 2010 07:07
Last Modified:16 May 2016 13:29

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