Richard E. Schramm

Bio: Richard E. Schramm is an academic researcher. The author has contributed to research in topics: Hydrography & Ocean dynamics. The author has an hindex of 3, co-authored 9 publications receiving 35 citations.

CTD Observations in the Coastal Transition Zone off Northern California, 16-25 February 1987.

Abstract: : Wecoma cruise W8702B was conducted in February 1987 as part of the pilot study for the Coastal Transition Zone project. CTD observations were made in the coastal transition zone off northern California between 37.5 N and 41.5 N. Stations were planned along three alongshore transects, at distances of 60, 90 and 150 km from the coast. Strong winds (with speeds greater than 35 kts) prevented the completion of the survey, but 38 stations were completed successfully. They were concentrated along lines 60 and 90 km from the coast. Maximum sampling depth at most stations was 500 m. Temperature and salinity were measured at all stations; light transmission was also measured at the first 23 stations. This report presents vertical profile plots and tabulations of data at selected depths for each station, and vertical sections of temperature, salinity and density anomaly for the two long alongshore sections.

CTD observations off Oregon and California: R/V WECOMA: July 1983 - April 1984

Abstract: Master files scanned at 600 ppi (256 Grayscale, Black and White) using Capture Perfect 3.0 on a Canon DR-9080C in TIFF format. PDF derivatives scanned at 300 ppi (256 Grayscale, Black and White) using Capture Perfect 3.0 and OmniPage Professional 15.0 for textual OCR on a Canon DR-9080C.

CTD observations in the coastal transition zone off Northern California from R/V Wecoma, July to August 1988

Abstract: : Wecoma cruise W8807A was conducted in late July and early August 1988 as part of the Coastal Transition Zone project CTD observations were made over a standard grid in the coastal transition zone off northern California between 37 deg N and 395 deg N that was occupied repeatedly during June, July and August; this cruise completed the sixth survey A total of 88 CTD stations were completed successfully; 68 of these stations were at standard grid positions Additional sections were added at the southwest corner and the north side of the grid, and along the northern portion of an alongshore line occupied four times in 1987 Maximum sampling depth at most stations was 500 m Temperature, salinity, light transmission and fluorescence were measured at all stations This report presents vertical profile plots and tabulations of data at selected depths for each station; vertical sections of temperature, salinity and potential density anomaly (sigma-theta), and maps of temperature, salinity, potential density anomaly, and dynamic topography Wecoma cruise W8806B (28 June to 24 July 1988) completed 13 transects along the D-line making primarily microstructure and towed thermistor chain observations, but CTD observations were also made A total of 51 CTD stations were completed

The nature of the cold filaments in the California Current system

Abstract: The velocity fields and water properties associated with cold filaments in the California Current are described on the basis of data from the Coastal Transition Zone experiment. Combined with previous field surveys and satellite imagery, these show seasonal variability with maximum dynamic height ranges and velocities in summer and minimum values in late winter and early spring. North of Point Arena in spring-summer, the flow field on the outer edge of the cold water exhibits the character of a meandering jet, carrying fresh, nutrient-poor water from the farther north on its offshore side and cold, salty, nutrient-rich water on its inshore side. At Point Arena in midsummer, the jet often flows offshore and continues south without meandering back onshore as strongly as it does farther north. At the surface, the jet often separates biological communities and may appear as a barrier to cross-jet transport, especially north of Point Arena in March-May.

The evolving structure of an upwelling filament

Abstract: The evolution of an upwelling filament was studied over a 2-week period by using satellite infrared images, and its thermohaline structure was mapped in situ The surface velocity field consisted of a large meander extending offshore for at least 300 km The northern branch was ∼40 km wide, flowing offshore at a peak velocity of 055 m/s; the southern branch was flowing inshore at 035 m/s The offshore transport was more than 106 m3 s−1, larger than the Ekman transport The meander was unstable to barotropic instabilities at a scale of ∼15 km From a succession of images a surface convergence γ ≈ 8·10−6 s−1 over 20 km was observed near the sharp front limiting the filament to the south The ∼350 m width of the front indicates a separation of scales between the large-scale strain field and the mixed-layer turbulence parameterized with an eddy diffusion coefficient KH ≈ 025 m2 s−1 Thermohaline layers that originated at the convergence near the sharp front suggest a secondary circulation subducting denser waters to the south underneath the lighter northern water

CTD and velocity surveys of seaward jets off northern California, July 1981 and 1982

Abstract: Two mesoscale surveys were conducted (in July 1981 and July 1982) near Point Arena, California, to determine the structure and circulation associated with tongues of cold surface water extending seaward from the coastal zone. Both surveys were designed at sea on the basis of available satellite IR data, and each was completed in less than a week. Sampling extended 100 km alongshore and 150 km (1981) to 250 km (1982) offshore, and included conductivity, temperature, and depth casts to 500 dbar, and continuous ocean current profiling to 150 m by means of a Doppler acoustic log. Both surveys showed that the tongues of cold water seen in the satellite images were the surface manifestation of hydrographic and current anomalies that extended to a depth of at least 100 m. In each case, strong seaward flow was observed along the northern edge of the cold tongue, which also marked a shallow water mass boundary between low-salinity ( 33.2 ppt) waters to the south. The seaward jets were very strong (up to 80 cm/s) and narrow (30 km), with strong shears (up to 10 -2 S -1 in the vertical and up to 10 -' s -1 in the horizontal). They were largely geostrophic, had transports exceeding 1.5 sverdrups, and can persist for 2-3 weeks. The seaward jets seemed to be continuous with southward flowing alongshore coastal jets. There is evidence that the seaward jets are recurrent features in the vicinity of Point Arena.

Satellite observations of phytoplankton variability during an upwelling event

Abstract: A sequence of satellite images of near-surface phytoplankton pigment concentrations and sea surface temperature together with concurrent surface measurements are used to study an upwelling event during the Coastal Ocean Dynamics Experiment off northern California. These data sets show a high degree of temporal and spatial variability during this episode. Recurrent patterns in this variability give insight into the dynamics of coastal upwelling and its effects on biological distributions. Simple models of coastal upwelling cannot explain the observed phenomena in the CODE region. Satellite estimates of phytoplankton growth rates were about 0.8 day −1 near persistent upwelling centers.