Study On Diurnal Variation Correction Of Satellite Sea Surface Temperature

It appears a near-surface diurnal warming layer due to the affect of solar heating during the daytime. It's necessary to correct for the diurnal warming when the multi-sensor satellite Sea Surface Temperature (SST) are merged due to the different acquisition time of satellite observations. Without considering the effect of diurnal warming of Sea Surface Temperature (SST), the Numerical Weather Prediction and climate models may be incorrect. The Global Ocean Data Assimilation Experiment (GODAE) team advised that the foundation SST—the SST without any diurnal warming should be provided. In order to get the foundation SST, diurnal variation must be removed from the satellite SST products.In this paper, firstly, the in situ measurements of SST by the shipboard Infrared Sea Surface Temperature Autonomous Radiometer (ISAR) and the sea surface wind speed data from the ship Vessel Manage System (VMS) are used to observe the SST diurnal variation and to analyze the relation between the wind speed and SST variation. Secondly, the correction of AMSR-E SST and NOAA AVHRR SST data in the Northwest Pacific are carried out using an empirical model. The results show relatively large error since the study region and the data used for the model are different. In order to get a model applicable in this region, the AMSR-E and AVHRR SST data in 2008 with the AMSR-E sea surface wind speed match-up data and calculated solar radiation data are used to regress the coefficients in the empirical model, and the day and night satellite SST difference in 2009 are compared with the model calculations. It shows that, for the correction of AMSR-E and AVHRR SST, the error are 0±0.38°C and -0.02±0.21°C respectively. The new model can be applied for the diurnal variation correction of the satellite data in Northwest Pacific. Finally, the new model is used to correct AMSR-E and AVHRR SST data in year 2009.