Temperature structure in the North Atlantic and Indian Oceans is presented in monthly mean charts at 100-ft (30-m) depths, surface to 492 ft (150 m). These charts were constructed from bathythermograph (BT) data obtained from 1941 to 1970, hydrocast data, means extracted from published charts, and unpublished tabulations of means. The charts were traced from computer-generated plots made directly from 1 deg quadrangle temperature means. Annual cycle temperature curves, at 10-deg longitude and 5-deg latitude intervals, contrast the remarkable changes in seasonal cycles from the northern latitudes, where the greatest change is at the surface, to the equatorial current region, where the annual range at the surface is very small and the subsurface range is large. The occurrences of middepth temperature maxima or minima also can be seen on these curves. Tight horizontal temperature gradients are associated with current, water mass boundaries or, beneath the surface, with the intersection of the depth level with the thermocline, defined as the depth where the temperature is 2 F(1.1 C) less than the surface temperature. Charts showing the temperature difference between the surface and 400 ft (120 m) are an estimate of the strength of the thermocline gradient between the top of the thermocline and 400 ft. Salinity charts are presented for the six depth levels. They are all-data means, rather than true annual means, based on the 1969 National Oceanographic Data Center hydrocast tapes. Charts of annual mean temperatures and temperature ranges are also presented for the six depth levels. Data analysis was a combination of objective computer and subjective time and space analyses, and means are available on computer tapes. (Author) Original contains color plates: All DTIC and NTIS reproductions will be in black and white. Includes errata sheet.
Physical and Dynamic Oceanography ; Temperature ; Oceans ; Salinity ; Depth ; Seasonal Variations ; Charts ; Range(Extremes) ; North Atlantic Ocean ; Thermoclines ; Indian Ocean ; Atlases
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