摘要
To estimate sea surface temperature(SST)with high accuracy from radiometrie measure- ments,it is no longer acceptable to assume that sea surface emissivity is unity or any other con- stant.This note presents an investigation of the desirable emissivity accuracy in relation to re- trieval.It was found that 1% error in surface emissivity can cause up to 0.7 K error in the re- trieved SST,although this sensitivity is often reduced to about 0.5 K on average because of the downward atmospheric radiation at surface partially compensates for the emissivity error.Since the downward atmospheric radiation ratio is controlled to a large extent by the integrated water vapor in the atmosphere and,secondarily,by view angle,the sensitivity of SST retrieval to surface emis- sivity has been computed as a function of these two parameters.
To estimate sea surface temperature(SST)with high accuracy from radiometrie measure- ments,it is no longer acceptable to assume that sea surface emissivity is unity or any other con- stant.This note presents an investigation of the desirable emissivity accuracy in relation to re- trieval.It was found that 1% error in surface emissivity can cause up to 0.7 K error in the re- trieved SST,although this sensitivity is often reduced to about 0.5 K on average because of the downward atmospheric radiation at surface partially compensates for the emissivity error.Since the downward atmospheric radiation ratio is controlled to a large extent by the integrated water vapor in the atmosphere and,secondarily,by view angle,the sensitivity of SST retrieval to surface emis- sivity has been computed as a function of these two parameters.
