AVHRR SST Retrieval Using Variation Algorithm And Evaluation

Sea surface temperature(SST)plays a fundamental role in the process of air-sea interaction.Obtaining a high-precision SST has important scientific and practical significance for the research of atmospheric science and marine science.In this paper,based on the variational theory,a SST retrieval system of satellite observation was constructed,and the MetOp-A/AVHRR SST was retrieved.The main work is as follows:(1)SST retrieval system construction:Based on the variational theory,a SST retrieval system for satellite observations is constructed.The system is composed of data pre-processing,SST retrieval pre-processing,SST retrieval,diagnosis,and evaluation.The data pre-processing section is focus on satellite calibration and format conversation.The SST retrieval pre-processing section carries out bias correction and quality control of satellite observation.The SST retrieval section performs SST retrieval based on the background field,observation field and parameter settings.The diagnosis section is responsible for monitoring various variables in the SST retrieval.The evaluation section is responsible for the comparative analysis of SST products.(2)The effect of satellite data quality control and bias correction:According to the quality control,eliminate pixels such as solar short-wave radiation pollution,cloud pollution,and surface toemissivity effects.Bias correction was made using one-dimensional cubic spline interpolation to obtain a correction value.The results of quality control and bias correction show that,the observation pixels with poor quality can be effectively eliminated and the system bias of satellite observations can be corrected well.(3)AVHRR SST retrieval and evaluation:MetOp-A/AVHRR SST retrieved by using variation algorithm.SST retrieval was done for one month.The evaluation was done in the global regional and the weather system active regional.According to the result,the variational SST retrieval result(VAR SST)is basically superior to the SST product(GBL SST)obtained by retrieve the same satellite using statistical regression method.In addition,the VAR SST also improved the GBL SST shortcomings about time fluctuations.According to the research,variation algorithm can correct the atmospheric attenuation in satellite remote sensing more effectively and get a higher accurate SST,especially in the area of the complex weather system.That's because the atmospheric temperature and water vapor mixing ratio were considered in this algorithm.