Net radiation estimates in a salt marsh of the Bahía Blanca estuary, Argentina

ALEJANDRO J. VITALE; M. CINTIA PICCOLO

Bahía Blanca, Argentina

Conferencia; ECSA 44; 2008

Instituto Argentino de Oceanografía

Energy budget studies of coastal salt marshes depend critically on good net radiation estimates. The knowledge of net radiation is a necessary parameter to define surface processes. But it is not often measured by meteorological stations. In most practical situations the net radiation is inferred by parameterizations from simple global solar radiation measurements. The aim of this work is to report on a net radiation parameterization scheme.  Linear regression relations between net radiation (RN) and global solar radiation (Rs) are presented for Villa del Mar salt marsh in the Bahía Blanca estuary. Radiation measurements were performed using a net radiometer and a pyranometer. Simultaneous measurements of water temperature and meteorological data were made at the salt marsh. The model requires the global solar radiation, near-surface air temperature, water temperature and vapor pressure data. A set of statistical procedures was used to evaluate the performance of the equations: bias (BIAS), root mean square error (RMSE), mean absolute error (MAE) and percent mean relative error (PMRE). The mean relative error (PMRE) was approximately 18% and the root mean square error (RMSE) was approximately 22Wm−2 for all time series. After this study, it is evident that a simple model based on surface shortwave radiation, water temperature and meteorological parameters could provide appropriate net radiation estimates of the salt marsh.