The diurnal variation of turbulence parameters at Trombay Site

The diurnal variation of meteorological parameters like temperature, relative humidity, solar radiation, wind speed etc. is well known and readily available in literature. As opposed to this, the diurnal variation of friction velocity (u*), heat flux (Ho), and the Monin Obhukhov length (L) which are indicators of turbulence at a site are scantily reported. In this study, the sonic anemometer data collected at Gamma garden during 2009-2013 are used to derive the monthly and annual average diurnal variation of u*, Ho and L which are indicators of turbulence. In this paper, the diurnal variation of u* and Ho alone are discussed. In order to study the diurnal variation of u* and Ho for Trombay site, the sonic anemometer data collected at Gamma Garden, Bhabha Atomic Research Centre, Trombay at an interval of 15 minutes during 2009 -2013 are utilized. This data includes three components of velocity (u, v, w), their standard deviation (σ_u, σ_v,σ_w), wind speed, wind direction and turbulence measurements like friction velocity (u*), heat flux (H₀), momentum flux (mf), drag coefficient (C_d), the Monin Obhukhov Length (L) and atmospheric stability. The 15 minutes interval data sets were first processes to generate hourly average values, and these were subsequently utilized to generate monthly average values for each hour