RESPONSE OF GLOBAL UPPER OCEAN TEMPERATURE TO CHANGING SOLAR IRRADIANCE

By focusing on time sequences of basin-average and global-average uppe r ocean temperature (i.e., from 40 degrees S to 60 degrees N) we find temperatures responding to changing solar irradiance in three separate frequency bands with periods of >100 years, 18-25 years, and 9-13 yea rs. Moreover, we find them in two different data sets, that is, surfac e marine weather observations from 1990 to 1991 and bathythermograph ( BT) upper ocean temperature profiles from 1955 to 1994. Band-passing b asin-average find each frequency component in phase across the Indian, Pacific, and Atlantic Oceans, yielding global-average records with ma ximum amplitudes of 0.04 degrees +/- 0.01 degrees K and 0.07 degrees 0 .01 degrees K on decadal and interdecadal scales, respectively. These achieve maximum correlation with solar irradiance records (i.e., with maximum amplitude 0.5 W m(-2) at the top of the atmosphere) al phase l ags ranging from 30 degrees to 50 degrees. From the BT data set, solar signals in global-average temperature penetrate to 80-160 m, confined to the upper layer above the main pycnocline. Operating a global-aver age heat budget for the upper ocean yields sea surface temperature res ponses of 0.01 degrees-0.03 degrees K and 0.02 degrees-0.05 degrees K on decadal and interdecadal scales, respectively, from the 0.1 W m(-2) Penetration of solar irradiance to the sea surface. Since this is of the same order as that observed (i.e., 0.04 degrees-0.07 degrees K), w e can infer that anomalous heat from changing solar irradiance is stor ed in the upper layer of the ocean.