Estimation of ground heat flux from soil temperature measurements

3^rd International Conference on Hydrology & Meteorology

September 15-16, 2014 Hyderabad International Convention Centre, India

R Shrivastava, Indumathi S I, R B Oza, M N Hegde and K S Pradeepkumar

Accepted Abstracts: Hydrol Current Res

Abstract :

The ground heat flux is one of the components of the surface energy balance equation at the earth atmosphere interface. The estimation of the ground heat flux requires the knowledge of soil temperature variation as a function of depth. There are four Mini Boundary Layer Masts (MBLM) installed at Kaiga with sensors for continuous measurement of soil temperature at surface (0 cm) and depths of -5 cm, -10 cm, -20 cm, -50 cm and -100 cm. This study describes the use of these data and the one dimensional heat conduction equation to estimate the ground heat flux. The ground heat flux values are estimated numerically. At the same site, the net radiation data are obtained from the individual measurements of short and long wave radiation. The ground heat flux can also be obtained as a fraction of the net radiation and a comparison of the two methods of estimating the ground heat flux is presented. At present, the study is carried out for March 2013 as a demonstration of the method. Considerable diurnal variation in soil temperature is seen up to a depth of ~ 20 cm from the surface. Beyond that the soil temperature remains practically constant with time. Some differences are noted between the two methods of estimating ground heat flux especially in the peak value. This could be because of the value of thermal conductivity used in the equation. This study demonstrates the utility of soil temperature measurements in the estimation of the ground heat flux.

Biography :

R Shrivastava is working in the Environmental Modeling Section of Radiation Safety Systems Division. Her field of work is numerical weather prediction using advanced models like TAPM and WRF for DAE sites. Her assignment also includes application of weather prediction data to study atmospheric dispersion of pollutants and radiological dose computation due to releases from various nuclear facilities.