A comparison of upwelling events in two locations: Oregon and Northwest Africa

Intensive observations of the low frequency (less than one cycle per day) response of upwelling regimes to fluctuations in the wind have been made in two locations: the Oregon coast near 45°15\u27N, and the Northwest African coast at 21°40\u27N. Both regimes show an equatorward coastal jet at the surface, quasi-barotropic fluctuations in the alongshore flow, and a poleward undercurrent...

Observations of the coastal upwelling region off Oregon during 1972

Observations of wind, currents, sea level and hydrography obtained during the 1972 Coastal Upwelling Experiment (CUE-I) are described. Only phenomena with periods longer than a day are considered. One section describes the changes observed during a period of variable winds in early July 1972. Another describes a ribbon of relatively cool water observed early in the upwelling season and attributes its existence to advection of Subarctic water by the coastal jet associated with upwelling. A third section describes the seasonal development of the upwelling regime between April and October 1972. These studies are combined with other studies of CUE-I data to provide a partial description of the upwelling regime which is compared to the conceptual model developed prior to CUE-I. It is concluded that the vertical and onshore velocity fields are as yet largely unknown. The alongshore velocity field includes southward surface flow with a coastal jet, a persistent vertical shear with deeper velocities northward relative to the surface and high coherence with the wind and sea level at periods of several days. A poleward undercurrent is observed, but it may not be an integral part of the upwelling regime. The hydrography has a strong seasonal cycle. Differences between any two sections between April and October l972 are smaller than between any of these and a section occupied in January 1973. Oscillations in the wind with periods of several days cause significant changes in the region inshore of 10 km and in the upper 20 m further offshore. Subsurface temperature observations are not coherent with the wind at periods of several days

A study of the relationship between local winds and currents over the continental shelf off Oregon

This thesis demonstrates that at low frequencies (periods longer than 2.5 days) local currents off the coast of Oregon are closely related to the wind. Wind and current observations made during August and September 1969 are described and compared to demonstrate that a relationship exists; the physics of the interaction is not understood. The data are described as functions of both time and frequency. Spectral analysis shows that wind and current were related at frequencies less than 0.017 cycles per hour and at the diurnal frequency; at other frequencies they are apparently not related. The wind and current were then filtered to suppress frequencies higher than 0.017 cycles per hour; they are shown as functions of time. Comparison of the time series reveals certain features of the relationship between wind and current. The current can be considered to be the sum of two parts: a "response" current, which is related directly to the wind, and a "residual" current which is also variable. The amplitude of the response depends on the amplitude of the wind and on the density profile of the water. The time lag between the wind and the response current was variable; on a few occasions the current led the wind. Both the response and the residual current were generally parallel to the bottom contours. The residual current seems to change during periods when the response current is interrupted, so that short current records are not indicative of the mean flow

Hydrographic data from a large scale West Coast shelf experiment and the low level waste ocean disposal program : R/V Wecoma, Cruise W8108B, 24 August - 6 September 1981

CTD observations were made near Coos Bay at 43°08'N, off Crescent City at 41°54'N and in the vicinity of the LLWODP Pacific Study Area W-N west of Cape Mendocino between 24 August and 6 September 1981. The maximum sampling depth was 4405 db. This data report includes vertical sections, mesoscale maps, and vertical profile plots and listings at standard depths for each of the 29 CTD stations

Vertical sections and mesoscale maps of temperature, salinity and sigma-t off the coast of Peru, July to October 1976 and March to May 1977

In this report we will present vertical sections of temperature, salinity and sigma-t from both CTD and bottle casts made on legs 1-5 of the R/V Eastward during JASON, and from CTD casts made on legs 1, 2 and 4 of the R/V Melville and legs .2 and 4 of the R/V Columbus lselin during MAM 77

Coastal upwelling experiment hydrographic data report : June-August 1973

Hydrographic observations were made over the continental shelf and slope off Oregon during the 1973 Coastal Upwelling Experiment (CUE-II) from three ships: R/V OCEANOGRAPHER, R/V THOMAS G. THOMPSON, and R/V YAQUINA. This report contains the observations made on four YAQUINA cruises between June and August 1973 (Table I). Observations were made in the vicinity of the CUE-II buoy garden (Figure 1). The report contains a separate section for each of the four cruises, with a cruise narrative, maps showing station positions, profiles of temperature, salinity, and sigma-t for groups of stations, and a listing of the observed and computed parameters at standard depths

Cold halocline, increased nutrients and higher chlorophyll off Oregon in 2002

Observed changes in the nutrient levels in the halocline of the California Current during 2002 indicated a natural eutrophication that was accompanied by increased chlorophyll and oxygen in surface water. Decreased oxygen in the lower water column over the shelf indicated that much of the phytoplankton production was respired rather than passed on to higher trophic levels. In 2002 the halocline water was >1ºC colder than usual and 0.5ºC colder than any previous observation. Four transect lines off the coast of Oregon show a 50% increase in nitrate, phosphate and silicate at 33 psu in 2002 compared to 1998–2001. The increase in nutrients resulted in a 2-fold increase in chlorophyll standing stocks during the summer of 2002 compared with the preceding four years. A significant portion of the increased production was subsequently respired resulting in low oxygen water over the shelf

Ancillary hydrographic data from the Coastal Ocean Dynamics Experiments : CODE-1 Legs 3 and 8 and CODE-2 LEGS 10 and 13

During some of the CODE mooring deployment and recovery cruises, CTD observations were made on an ancillary basis. In conjunction with the recovery of the CODE-2 array, CTD observations were made during 3-5 August (CODE-2 Leg 10) and 19 August (CODE-2 Leg 13). The CTD observations were made alongside current meter moorings and along the CODE Central section. Maximum sampling depth was 505 m. This report includes vertical sections and offshore profiles to summarize the Code Central line data, and vertical plots and standard depth listings for each of the 31 stations. Ancillary CTD observations were also made during 20-21 April 1981 (CODE-1 Leg 3) and 19 July 1981 (CODE-1 Leg 8). These CTD observations were all made adjacent to the current meter mooring C-4 on the COC line. Vertical profile plots and listings of the data at standard depth are presented for these 17 stations

CTD observations off Oregon and California : R/V Wecoma, W8205A and Code 2 Leg 8, 18 May - 4 June 1982

CTD observations were made in the Code region near Pt. Arena on the northern California coast at 39°N, off Coos Bay at 43°12'N, off Crescent City at 41°54'N, of Eureka at 40°51'N, off Half Moon Bay at 37°25'N, off Pt. Purisima at 34°45'N and in the Santa Barbara Channel during 18 May - 3 June 1982. The observations in the Code region were made along seven sections: Irish Gulch, Arena, North, Code Central, Code-2 Central and Ross lines and along the hundred fathom contour. Maximum sampling depth was 1000 m. This report includes vertical sections, mesoscale maps and offshore profiles to summarize the data, and vertical profile plots and standard depth listings for each of the 178 stations

Hydrographic data from the first coastal ocean dynamics experiment : Leg 4, 25 April - 7 May 1981

CTD observations were made in the Code region near Pt Arena on the northern California coast at 39°N, off Purisima Pt. at 34°45'N and off Crescent City at 41°54'N, during 25 April - 7 May 1981. The observations in the Code region included four repeated sections along the Central Line, two mesoscale surveys of the shelf-slope region, and two alongshore sections. The maximum sampling depth was 1000 m. This data report includes vertical sections, mesoscale maps and offshore profiles to summarize the data, and vertical profile plots and listings of the data at standard depths for each of the 154 CTD stations