Multichannel sea surface temperature (MCSST) measurements with the NOAA 7 advanced very high resolution radiometer (AVHRR) have been corrected for the effects of the El Chichon aerosol layer by using a previously developed method of inferring the aerosol optical thickness (&tgr;) from the channel 1 radiance. A theoretical model shows that the error in the MCSST is directly proportional to &tgr;sec &thgr;, where &thgr; is the satellite zenith angl. Data using moored buoy SST's and AVHRR MCSST's at five locations verify this relationship. Analysis of the data also shows empirically that the MCSST error is more closely related to ln (&tgr;sec2&thgr;). Linear regressions for these relationships for the combined data of two locations show correlation coefficients of 0.80 and 0.88 for the &tgr;sec &thgr; and ln (&tgr;sec2&thgr;) relationships, respectively. These regression lines are used to correct the MCSST values in the independent data sets of the other three locations. Statistics of the comparison between the corrected MCSST's and the buoy SST's show that the root mean square difference in the MCSST and buoy SST comparison is 1.14¿C and 1.01¿C for the &tgr;sec &thgr; and ln (&tgr;sec2&thgr;) relationships, respectively. These values are close to the value of 1.05¿C found in an extensive study at NOAA of an earlier MCSST algorithm that was not influenced by aerosols. Before this correction, considerable daytime data were rejected by the MCSST algorithm, and errors as large as 7¿C were observed. It appears that the correction procedure can be used in the presence of partial cloud in a pixel, since both the MCSST and the aerosol algorithms interpret the partial cloud as a uniform haze. Thus the technique also results in the retrievel of more MCSST values (than are currently available with the NOAA cloud filter tests) in the presence of clouds in normal aerosol conditions. The techniques also offers the potential of increasing the accuracy of MCSST measurements in normal atmospheres where the aerosols are mostly in the troposphere.