Data from the Global Ocean Surface Temperature Atlas (GOSTA), which includes 60 million ship reports for the 1856--1988 period, have been used to study global night marine air temperature (MAT) and sea surface temperature (SST) interannual variations. Linear regression has been used to establish trends over two periods: 1888--1988, a period often used for land station analyses, and 1856--1988. For global MAT the trends for the century beginning in 1888 computed for these periods are 0.49¿ C and 0.29¿ C, respectively. Stepwise linear regression is used to relate the marine time series to three physical variables thought to influence surface temperatures, namely, changes in solar radiation output, changes in atmospheric transmission for solar radiation, and changes in the global surface pressure field. Indices of these variables used are new computations of solar irradiance, atmospheric turbidity at Sonnblick, Austria, supported by sunshine records from Japan, and the Southern Oscillation Index (SOI).

When MAT and SST series are examined for the globe, northern and southern hemisphere separately, the largest fraction of the variance (45% for the global MAT, 35% for global SST) is accounted for by turbidity changes, while the tropical east Pacific shows the largest fraction (45% for MAT, 49% for SST) associated with SOI changes. Modeled solar irradiance variations contribute the second most important factor in controlling marine temperature fluctuations in the southern hemisphere. The tropical west Pacific SST is relatively insensitive to the three parameters, in accordance with previous suggestions that the temperature there is limited by evaporation. When the residuals are examined after account is taken of these factors, the global MAT trend for 1888-1988 is reduced to 0.24¿ C. With the present approach the apparent twentieth century temperature increases can be viewed as partly due to a recovery from cooling at the turn of the century, probably associated with volcanic activity. ¿ American Geophysical Union 1990