The problem of atmospheric corrections in determining the temperature of the ocean surface (TOS) is studied based on computer modeling taking into account the regional variability of vertical temperature and moisture content profiles in the atmosphere. We used our developed approach, which enables one to analyze physical factors affecting the errors in determining the TOS and to obtain the substantiated objective estimates of these errors. In addition to the two-angle scheme of measurements described earlier (Atmospheric Optics 2, No. 7 (1989), ibid. 4, No. 8 (1991)) the spectral scheme is studied for measuring in the atmospheric transparency window within two spectral intervals 10-13 mm. As the calculation results show, the accuracy in determining the TOS under conditions of real errors in recording the IR radiation varies within the limits from 0.1 to 0.7 K, depending on the regional characteristics of the atmosphere. The angular scheme accounts for the atmospheric noise slightly better, however, it is more sensitive to the instrumental errors. Under extreme condition of the moist tropical regions, the angular scheme of measurements gives the advantage even in the presence of instrumental errors.