摘要:

Insolation, net radiation, and various oceanic and atmospheric variables were measured at sites 13 and about 120 km off the coast of Oregon in July and August 1973. A total often 24‐hour stations were occupied. The daily mean net solar radiation ranged from 0.10 to 0.40 cal cm−2min−1, and large spatial variations of radiation in this upwelling region were present. The daily mean values were not closely related to the proportion of sky covered with clouds, but a mean from all the stations was in reasonable agreement with one cloud formula. The net long‐wave radiation varied from about −0.01 cal cm−2min−1under overcast skies to −0.10 cal cm−2min−1under clear skies. Daily mean values appear closely related to cloud amount, and a cloud factor of 1 ‐ 0.9C, as suggested by previous workers, seems appropriate for stratocumulus clouds. The measured clear‐sky net long‐wave radiation is appreciably less than that given by numerous widely used formulas but is supported by other observations and by a fo

ISSN:0148-0227    

DOI:10.1029/JC080i006p00839

年代:1975

数据来源: WILEY

摘要:

The ratios of short‐lived radon (222Rn) daughter product activity to long‐lived210Pb in surface air at a few stations in India are compared with similar ratios at a number of other locations. It is noted that where systematic measurements are available, the seasonal changes in the activity ratios are within a factor of 2. Also, all the available average ratios from the various locations fall within the limits 6000 ± 5000. It is suggested that with properly averaged ratios the aerosol residence time can be calculated correct to possibly a factor of 2 if vertical diffusion is also taken into account. Some advantages of using the ratios of Rn/210Pb compared with other pairs of isotopes for calculating aerosol residence times are pointed

ISSN:0148-0227    

DOI:10.1029/JC080i006p00845

年代:1975

数据来源: WILEY

摘要:

Broad scale horizontal variations of the main thermocline south of Bermuda have been revealed by an extensive ocean measurement program over several years. The primary physical property of the ocean sampled during these studies was the sound speed because of interest in underwater sound propagation. For the oceanographer the sound speed measurements in the main thermocline provide information similar to ocean temperature measurements except that there is also a dependence of the sound speed on the salinity and the pressure. In the summer of 1962, 31 sound speed profiles were measured. This measurement was followed in the summer of 1964 with 67 sound speed profiles. Complex horizontal variations of a surface of constant sound speed found near the depth of 800 m were the beginning indications of spatial scales of about 240 ± 60 miles (440 ± 110 km) of undulations in the main thermocline. In the summer of 1966, 115 sound speed profiles were measured, most of which were distributed on a rhombic grid pattern with 65 miles (120 km) between stations. These observations are compared with the 1962 and 1964 measurements. The 1966 measurements confirm the existence of a spatial scale of about 240 miles (±60 miles) (440 ± 110 km) as well as the existence of other scales in this ocean region. The spatial variations are indicated by a contour pattern of the depth variations (∼300 m) of a 1502‐m/s sound speed surface near the depth of 800 m in the main thermocline, where the vertical thermal gradient is large. The observations are interpreted as evidence for Rossby waves or baroclinic waves possibly of finite amplitude that show northwest‐southeast

ISSN:0148-0227    

DOI:10.1029/JC080i006p00849

年代:1975

数据来源: WILEY

摘要:

Results of measurements of short‐period internal waves (periods less than an hour) in the seasonal thermocline in the Black and Caspian seas and some regions of the Atlantic and Indian oceans are discussed. The line sensors of temperature (i.e., the pieces of wire whose electrical resistance varies in accordance with the average temperature of the layer bounded between the ends of the sensor) were widely used. The lengths of the line sensor used were varied from 1 up to 100 m. Measurements with arrays of such sensors in horizontal plane and along the vertical were fulfilled. Records obtained are much more regular than those in cases of point temperature sensors and easy to analyze. It appears often that short‐period internal waves exist as groups (trains) of quasi‐harmonic oscillations. The frequency and wave number in the group are nonstable. The lowest mode of the oscillations is predominant. Sometimes the waves are standing

ISSN:0148-0227    

DOI:10.1029/JC080i006p00856

年代:1975

数据来源: WILEY

摘要:

Periodic features observed on the ocean surface from the Earth Resources Technology Satellite 1 have been interpreted as surface slicks due to internal wave packets. They appear to be generated at the edge of the continental shelf by semidiurnal and diurnal tidal actions and propagate shoreward. Nonlinear effects apparently distort the wave packets as they progress across the shelf. This observational technique constitutes a new tool for delineating two dimensions of the internal wave field under certain limited conditions.

ISSN:0148-0227    

DOI:10.1029/JC080i006p00865

年代:1975

数据来源: WILEY

摘要:

A packet of high‐frequency (period ∼8 min) internal gravity waves was observed on a precision‐depth recorder (PDR) chart while an anchor station was being conducted during the Cue 1 experiment off Oregon. The anchor station was located over the continental shelf and in the frontal zone associated with coastal upwelling. The packet appeared as a set of three oscillations (maximum peak‐to‐peak amplitude of 11 m) of a scattering layer located at a depth of about 20 m, which was immediately below the center of the permanent pycnocline (25.5–26.0 sigmat) at that time and location (water depth 80 m, 10‐km offshore). The scattering layer occurred at the depth of a chlorophyll A maximum; strong temperature, salinity, and sound speed gradients; and strong vertical shear of the horizontal velocity. Simultaneously, a series of surface slicks, oriented parallel to the isobaths and propagating onshore, was observed under conditions of light winds. From the spacing of the slicks a horizontal scale of 100 m was estimated; this scale corresponded most nearly to the wavelength of the first internal wave mode for the observed wave period. From time series of nearby moored current and temperature sensors, bursts of high‐frequency oscillations were noted to occur on semidiurnal tidal cycles. Such bursts had occurred a few hours before the internal wave packet was observed on the PDR. It is concluded that the semidiurnal baroclinic tide breaks down in the frontal zone off Oregon, forming large‐amplitude high‐frequency internal gravity waves. These waves can induce detectable surface slicks under light wind conditions and major perturbations of a shallow scattering layer

ISSN:0148-0227    

DOI:10.1029/JC080i006p00882

年代:1975

数据来源: WILEY

摘要:

Various internal wave frequency spectra of temperature, velocity, and coherences are computed by using linear wave functions and the energy model of Garrett and Munk (1972). The emphasis is on the frequency range close to the Väisälä frequencyn, where it is predicted that temperature spectra and coherence have a peak before a sharp cutoff. The model is strongly dependent on the local value ofn, its vertical gradient, and the wave number bandwidth of the wave fie

ISSN:0148-0227    

DOI:10.1029/JC080i006p00895

年代:1975

数据来源: WILEY

ISSN:0148-0227    

DOI:10.1029/JC080i006p00900

年代:1975

数据来源: WILEY

ISSN:0148-0227    

DOI:10.1029/JC080i006p00902

年代:1975

数据来源: WILEY