Search Results
You are looking at 1 - 3 of 3 items for :
- Author or Editor: Jack A. C. Kaiser x
- Journal of Physical Oceanography x
- Refine by Access: All Content x
Abstract
Measurements of the components of the heat balance of the upper 30 m of the ocean were made in the Bermuda area in August and September 1974. The quantities measured included surface downwelling and underwater downwelling and upwelling irradiance, surface net irradiance, heat content, and the bulk meteorological variables.
Under conditions of light winds, one or more layers of 1 to 10 m thickness form and persist at the surface. In some cases the bottom of the layers have sufficiently high Richardson numbers so that no vertical transport occurs through them, vastly simplifying the measurements and interpretation of their heat balance. These data illustrate several such cases. The net flux of heat from the layer at the surface is usually much larger than the bulk formulas predict in these light wind cases. When the winds are calm and the sea glassy, total heat fluxes of several kilowatts per square meter occur for several hours in the afternoon. This has been observed previously in the Sargasso Sea.
Generally twice during the day, the beat content of the upper ocean has an extremum, usually after sunrise and somewhat before sunset. At these times the net heat flow out of a layer is equal to the irradiance absorbed in the layer providing a simple determination of surface fluxes from irradiance measurements. These measurements show this feature clearly.
Abstract
Measurements of the components of the heat balance of the upper 30 m of the ocean were made in the Bermuda area in August and September 1974. The quantities measured included surface downwelling and underwater downwelling and upwelling irradiance, surface net irradiance, heat content, and the bulk meteorological variables.
Under conditions of light winds, one or more layers of 1 to 10 m thickness form and persist at the surface. In some cases the bottom of the layers have sufficiently high Richardson numbers so that no vertical transport occurs through them, vastly simplifying the measurements and interpretation of their heat balance. These data illustrate several such cases. The net flux of heat from the layer at the surface is usually much larger than the bulk formulas predict in these light wind cases. When the winds are calm and the sea glassy, total heat fluxes of several kilowatts per square meter occur for several hours in the afternoon. This has been observed previously in the Sargasso Sea.
Generally twice during the day, the beat content of the upper ocean has an extremum, usually after sunrise and somewhat before sunset. At these times the net heat flow out of a layer is equal to the irradiance absorbed in the layer providing a simple determination of surface fluxes from irradiance measurements. These measurements show this feature clearly.
Abstract
Measurements of underwater downwelling D, underwater upwelling U, both at 5 m, and surface down-welling irradiance I were taken over most of a 5-day period in August and September 1974 south and west of Bermuda. On clear days D/I reached a pronounced maximum at local noon, whereas U/I had a weak minimum at midday. On cloudy days both of the above ratios were larger at all times of the day and did not exhibit the midday maximum.
An absorption model for D/I is constructed by decomposing I into components from the sun, clear sky and clouds. The major differences between the components is their spectral and radiance distributions. Atmospheric water vapor and sea surface roughness effects are included. The model agrees with the experimental values of D/I to within 5% of I for A the data, and it reproduces the variation of this ratio with solar zenith angle and cloud cover.
Abstract
Measurements of underwater downwelling D, underwater upwelling U, both at 5 m, and surface down-welling irradiance I were taken over most of a 5-day period in August and September 1974 south and west of Bermuda. On clear days D/I reached a pronounced maximum at local noon, whereas U/I had a weak minimum at midday. On cloudy days both of the above ratios were larger at all times of the day and did not exhibit the midday maximum.
An absorption model for D/I is constructed by decomposing I into components from the sun, clear sky and clouds. The major differences between the components is their spectral and radiance distributions. Atmospheric water vapor and sea surface roughness effects are included. The model agrees with the experimental values of D/I to within 5% of I for A the data, and it reproduces the variation of this ratio with solar zenith angle and cloud cover.
Abstract
By measuring the time rate of change of temperature in the upper 65 m of the sea at night with a precision sounding device, the amount of heat transported upward at various depths and through the sea surface as a function of time during the night was determined. The heat flux through any surface of depth z was given by e −αt (1−Az ⅔) for z<z max (40–65 m). The amount of heat released from the sea surface ranged from 1.34 to 0.311 ly min−1, the release rate decreasing with time after sunset.
The data also allowed estimates of the spatially averaged thermal boundary layer thickness in the sea surface, 0.2 cm or less.
Abstract
By measuring the time rate of change of temperature in the upper 65 m of the sea at night with a precision sounding device, the amount of heat transported upward at various depths and through the sea surface as a function of time during the night was determined. The heat flux through any surface of depth z was given by e −αt (1−Az ⅔) for z<z max (40–65 m). The amount of heat released from the sea surface ranged from 1.34 to 0.311 ly min−1, the release rate decreasing with time after sunset.
The data also allowed estimates of the spatially averaged thermal boundary layer thickness in the sea surface, 0.2 cm or less.
