A study of mean monthly thermal conditions and inferred currents in Monterey Bay.

Abstract

Temperature data, collected over the past 40 years, was compiled and averaged in the first known study of mean thermal conditions throughout the waters of Monterey Bay. The following results were obtained: (1) The distribution of mean sea surface temperature in the Bay was obtained by calculating mean monthly values at selected grid points and drawing isotherms, (2) Progressive warming of the upper 100m was observed to occur in a nearly linear fashion with time, resulting in a maximum temperature increase of 1.8°C over the 29 year interval from 1931 to 1960. This implies that the intensity of upwelling is also decreasing with time, (3) Geographic variations in the rates of upwelling and downwelling, causing a relatively "warm tongue" along the Canyon axis, appeared to be a major element influencing the dynamics of the Bay, and (4) Mean currents were inferred from the topographies of mean monthly isothermal surfaces. Limited comparisons of the inferred flow to past measured currents were very encouraging and tended to support the feasibility of such an inference in the shallow waters and irregular topography of Monterey Bay.