Longwave radiation budget in the Mediterranean Sea

Direct measurements of infrared budget and meteorological parameters at sea were carried out in the western Mediterranean Sea during different seasons in the years 1989–1992. The spatial and time distribution of this data set allows us to perform an exhaustive test on the most widely used infrared budget bulk formulas. An underestimation of about 30 W/m2 is systematically observed, confirming previous results obtained by a limited data set. This discrepancy is independent of the time of the year and location of measurements, indicating an inability of the bulk formulas to reproduce the infrared Mediterranean budget. The completeness of the data set enables us to determine a new relation between infrared budget and meteorological parameters. Alternative expressions, to be used accordingly with the available data sets, are presented here.