Energy Fluxes and Greenhouse Gas Emissions from a Waste Lagoon

Energy fluxes from a waste lagoon located in South Central Kentucky are calculated using the Bowen Ratio energy balance (BREB) method. Also, relationships are found between meteorological variables and greenhouse gas (GHG) emissions from the waste lagoon. Measurements were taken on two floating stations situated near the center of the lagoon and at a land station located 20 meters from the bank of the lagoon. Meteorological data were taken at heights of 0.5 and 1.5 meters above the lagoon surface and GHG data was measured at a height of 50 cm above the lagoon surface on the floating station. Emission and meteorological data from five days in February 2009 that are characterized by mostly clear conditions and no rain are analyzed. Because the raw data fluctuated greatly, a 15-point moving average was utilized to smooth the data. The water vapor and energy fluxes are used to compute the sensible and latent heat fluxes along with estimates of the net radiation and lagoon heating flux. The energy fluxes showed a definitive diurnal pattern expected of such fluxes. Although some gases were not strongly correlated with any parameter, most gases depended on air temperature and/or the energy fluxes. The temperatures at 0.5 and 1.5 m were negatively correlated with most GHG concentrations. Of all the gases CO2 showed the highest correlation with air temperature at 0.5 m above the lagoon surface.