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• 1. [Article] Surface patterns in temperature, flow, phytoplankton biomass, and species composition in the coastal transition zone of northern California

  Satellite thermal imagery and in situ biological and physical data are presented that describe the spatial variability of phytoplankton biomass and species composition in relation to the physical structure ...

  Citation × Citation Citation Abstract Copy Title: Surface patterns in temperature, flow, phytoplankton biomass, and species composition in the coastal transition zone of northern California Author: Abbott, Mark R., Hood, Raleigh R., Huyer, Adriana, 1945-, Kosro, P. Michael, 1951- Satellite thermal imagery and in situ biological and physical data are presented that describe the spatial variability of phytoplankton biomass and species composition in relation to the physical structure at the sea surface during persistent upwelling off northern California. Surface patterns in temperature, geostrophic velocity, chlorophyll, and particle size structure show that the coastal zone was dominated by two water masses separated by a well-defined physical boundary. This boundary is apparent in satellite thermal imagery as a cold front and in dynamic height as a meandering jet in the California Current. On the landward side of the front (jet) we observed cold, coastal water that was relatively enriched in phytoplankton biomass, due to the presence of large diatoms. On the seaward side of the front (jet) we observed relatively warm water where the phytoplankton biomass was low and the diatoms were largely absent. Broad tongues and narrow filaments of cold, chlorophyll-rich water that extended over 100 km offshore were present in our study area. These features were bounded by the meandering coastal jet. The coldest, most chlorophyll-rich water in these tongues and filaments was located between the onshore and offshore flows in relatively slow moving water, but entrainment of coastal water into the jet was apparent. Title: Surface patterns in temperature, flow, phytoplankton biomass, and species composition in the coastal transition zone of northern California Author: Abbott, Mark R., Hood, Raleigh R., Huyer, Adriana, 1945-, Kosro, P. Michael, 1951- Satellite thermal imagery and in situ biological and physical data are presented that describe the spatial variability of phytoplankton biomass and species composition in relation to the physical structure at the sea surface during persistent upwelling off northern California. Surface patterns in temperature, geostrophic velocity, chlorophyll, and particle size structure show that the coastal zone was dominated by two water masses separated by a well-defined physical boundary. This boundary is apparent in satellite thermal imagery as a cold front and in dynamic height as a meandering jet in the California Current. On the landward side of the front (jet) we observed cold, coastal water that was relatively enriched in phytoplankton biomass, due to the presence of large diatoms. On the seaward side of the front (jet) we observed relatively warm water where the phytoplankton biomass was low and the diatoms were largely absent. Broad tongues and narrow filaments of cold, chlorophyll-rich water that extended over 100 km offshore were present in our study area. These features were bounded by the meandering coastal jet. The coldest, most chlorophyll-rich water in these tongues and filaments was located between the onshore and offshore flows in relatively slow moving water, but entrainment of coastal water into the jet was apparent. Close

• 2. [Article] SEASOAR and CTD observations during EBC cruises W9306A and W9308B, June to September 1993

  Citation × Citation Citation Abstract Copy Title: SEASOAR and CTD observations during EBC cruises W9306A and W9308B, June to September 1993 Author: Shearman, R. Kipp, Smith, Robert L. (Robert Lloyd), 1935-, Fleischbein, Jane, Oregon State University. College of Oceanic and Atmospheric Sciences, O'Malley, Robert T., Huyer, Adriana, 1945-, Kosro, P. Michael, 1951-, Barth, John A. Title: SEASOAR and CTD observations during EBC cruises W9306A and W9308B, June to September 1993 Author: Shearman, R. Kipp, Smith, Robert L. (Robert Lloyd), 1935-, Fleischbein, Jane, Oregon State University. College of Oceanic and Atmospheric Sciences, O'Malley, Robert T., Huyer, Adriana, 1945-, Kosro, P. Michael, 1951-, Barth, John A. Close

• 3. [Article] Central California Coastal Circulation Study : CTD observations, cruise 8401, February 1984

  Citation × Citation Citation Abstract Copy Title: Central California Coastal Circulation Study : CTD observations, cruise 8401, February 1984 Author: Chelton, Dudley B., Oregon State University. College of Oceanography, Kosro, P. Michael, 1951- Title: Central California Coastal Circulation Study : CTD observations, cruise 8401, February 1984 Author: Chelton, Dudley B., Oregon State University. College of Oceanography, Kosro, P. Michael, 1951- Close

• 4. [Article] Central California Coastal Circulation Study : CTD observations , cruise 8403, July 1984

  Citation × Citation Citation Abstract Copy Title: Central California Coastal Circulation Study : CTD observations , cruise 8403, July 1984 Author: Kosro, P. Michael, 1951-, Oregon State University. College of Oceanography, Chelton, Dudley B. Title: Central California Coastal Circulation Study : CTD observations , cruise 8403, July 1984 Author: Kosro, P. Michael, 1951-, Oregon State University. College of Oceanography, Chelton, Dudley B. Close

• 5. [Article] Central California Coastal Circulation Study : CTD observations, cruise 8404, October 1984

  Citation × Citation Citation Abstract Copy Title: Central California Coastal Circulation Study : CTD observations, cruise 8404, October 1984 Author: Kosro, P. Michael, 1951-, Oregon State University. College of Oceanography, Chelton, Dudley B. Title: Central California Coastal Circulation Study : CTD observations, cruise 8404, October 1984 Author: Kosro, P. Michael, 1951-, Oregon State University. College of Oceanography, Chelton, Dudley B. Close

• 6. [Article] SeaSoar CTD observations during the coastal mixing and optics experiment : R/V Endeavor cruises from 14-Aug to 1-Sep 1996 and 25-Apr to 15-May 1997

  Citation × Citation Citation Abstract Copy Title: SeaSoar CTD observations during the coastal mixing and optics experiment : R/V Endeavor cruises from 14-Aug to 1-Sep 1996 and 25-Apr to 15-May 1997 Author: Kosro, P. Michael, 1951-, Oregon State University. College of Oceanic and Atmospheric Sciences, O'Malley, Robert T., Erofeev, A. Y. (Anatoli Y.), Barth, John A., Pierce, Stephen D., Fleischbein, Jane Title: SeaSoar CTD observations during the coastal mixing and optics experiment : R/V Endeavor cruises from 14-Aug to 1-Sep 1996 and 25-Apr to 15-May 1997 Author: Kosro, P. Michael, 1951-, Oregon State University. College of Oceanic and Atmospheric Sciences, O'Malley, Robert T., Erofeev, A. Y. (Anatoli Y.), Barth, John A., Pierce, Stephen D., Fleischbein, Jane Close

• 7. [Article] Central California Coastal Circulation Study : CTD observations, cruise 8501, January 1985

  Citation × Citation Citation Abstract Copy Title: Central California Coastal Circulation Study : CTD observations, cruise 8501, January 1985 Author: Chelton, Dudley B., Oregon State University. College of Oceanography, Kosro, P. Michael, 1951- Title: Central California Coastal Circulation Study : CTD observations, cruise 8501, January 1985 Author: Chelton, Dudley B., Oregon State University. College of Oceanography, Kosro, P. Michael, 1951- Close

• 8. [Article] Physical versus biological spring transition: 2005

  In 2005, the onset of spring conditions in the physics of the coastal ocean (lowered sea level, spin-up of vertically-sheared equatorward coastal jet) came about 50 days later than average off Newport ...

  Citation × Citation Citation Abstract Copy Title: Physical versus biological spring transition: 2005 Author: Shearman, R. Kipp, Hickey, Barbara M., Pierce, Stephen D., Peterson, William T., Kosro, P. Michael, 1951- In 2005, the onset of spring conditions in the physics of the coastal ocean (lowered sea level, spin-up of vertically-sheared equatorward coastal jet) came about 50 days later than average off Newport Oregon, on May 24. There was a further delay of 50 days before the subsurface upwelled water penetrated into the anomalously stratified surface layer, becoming most available for biological activity. The warm anomaly in sea surface temperature which provided the surface cap was observed at mid-shelf locations from Washington to central California, but it ended sooner south of Oregon. Biological impacts of these delays to several trophic levels have been reported. Title: Physical versus biological spring transition: 2005 Author: Shearman, R. Kipp, Hickey, Barbara M., Pierce, Stephen D., Peterson, William T., Kosro, P. Michael, 1951- In 2005, the onset of spring conditions in the physics of the coastal ocean (lowered sea level, spin-up of vertically-sheared equatorward coastal jet) came about 50 days later than average off Newport Oregon, on May 24. There was a further delay of 50 days before the subsurface upwelled water penetrated into the anomalously stratified surface layer, becoming most available for biological activity. The warm anomaly in sea surface temperature which provided the surface cap was observed at mid-shelf locations from Washington to central California, but it ended sooner south of Oregon. Biological impacts of these delays to several trophic levels have been reported. Close

• 9. [Article] Mesoscale surveys over the shelf and slope in the upwelling region near Point Arena, California

  Repeated mesoscale surveys of a 40-km-wide, 100-km-long, coastal region near Point Arena, California, were conducted during the upwelling season (April-August) in 1981 and 1982. Each survey included conventional ...

  Citation × Citation Citation Abstract Copy Title: Mesoscale surveys over the shelf and slope in the upwelling region near Point Arena, California Author: Huyer, Adriana, 1945-, Kosro, P. Michael, 1951- Repeated mesoscale surveys of a 40-km-wide, 100-km-long, coastal region near Point Arena, California, were conducted during the upwelling season (April-August) in 1981 and 1982. Each survey included conventional conductivity-temperature-depth casts at standard locations over the continental shelf and slope between 38°N and 39°10'N, and continuous operation of a Doppler acoustic log to obtain velocity profiles in the 20- to 150-m depth range. "Synoptic" surveys covered the entire grid in 2-3 days. Winds were strongly favorable for upwelling during the three 1981 surveys and were weak or variable during the three 1982 surveys. Surface temperature and salinity fields reflect the influence of both the seasonal winds and day-to-day variations in the wind. Persistently low surface salinities offshore reflect the general southward advection of subarctic waters, and sporadic low salinities over the inner shelf reflect northward advection of local runoff through an intermittent narrow countercurrent along the coast. Circulation patterns during all but one of the surveys were very complex and included meandering equatorward flow, cyclonic and anticyclonic eddies, and inshore countercurrents. The simple two-dimensional, equatorward, baroclinic coastal jet usually associated with coastal upwelling was observed during only one of our surveys. Overall average fields are relatively simple. They show broad equatorward surface flow, a very weak inshore countercurrent, and a definite poleward undercurrent at the shelf break. Average temperature, salinity, and density fields are generally congruent with the average flow pattern. Average isotherms and isohalines are not strictly parallel to the coastline: south of the coastline bend at Point Arena, they diverge gradually from the coast. Comparison of average sections calculated from 10 matched pairs of Central and Arena lines (separated by 50 km) shows there are systematic differences between them. Warmer, fresher waters lie nearer shore (and in shallower water) off Point Arena than on the Central line; this suggests that the surface waters flowing past Point Arena have sufficient southward momentum to cross isobaths. Comparison of average velocity sections on these two lines shows some differences in structure; since the variability is large, these may not be significant. Comparison of the measured and geostrophic average shears suggests there is a significant ageostrophic component in the upper layers above 40 m; it may be the signature of an average wind-driven Ekman spira Title: Mesoscale surveys over the shelf and slope in the upwelling region near Point Arena, California Author: Huyer, Adriana, 1945-, Kosro, P. Michael, 1951- Repeated mesoscale surveys of a 40-km-wide, 100-km-long, coastal region near Point Arena, California, were conducted during the upwelling season (April-August) in 1981 and 1982. Each survey included conventional conductivity-temperature-depth casts at standard locations over the continental shelf and slope between 38°N and 39°10'N, and continuous operation of a Doppler acoustic log to obtain velocity profiles in the 20- to 150-m depth range. "Synoptic" surveys covered the entire grid in 2-3 days. Winds were strongly favorable for upwelling during the three 1981 surveys and were weak or variable during the three 1982 surveys. Surface temperature and salinity fields reflect the influence of both the seasonal winds and day-to-day variations in the wind. Persistently low surface salinities offshore reflect the general southward advection of subarctic waters, and sporadic low salinities over the inner shelf reflect northward advection of local runoff through an intermittent narrow countercurrent along the coast. Circulation patterns during all but one of the surveys were very complex and included meandering equatorward flow, cyclonic and anticyclonic eddies, and inshore countercurrents. The simple two-dimensional, equatorward, baroclinic coastal jet usually associated with coastal upwelling was observed during only one of our surveys. Overall average fields are relatively simple. They show broad equatorward surface flow, a very weak inshore countercurrent, and a definite poleward undercurrent at the shelf break. Average temperature, salinity, and density fields are generally congruent with the average flow pattern. Average isotherms and isohalines are not strictly parallel to the coastline: south of the coastline bend at Point Arena, they diverge gradually from the coast. Comparison of average sections calculated from 10 matched pairs of Central and Arena lines (separated by 50 km) shows there are systematic differences between them. Warmer, fresher waters lie nearer shore (and in shallower water) off Point Arena than on the Central line; this suggests that the surface waters flowing past Point Arena have sufficient southward momentum to cross isobaths. Comparison of average velocity sections on these two lines shows some differences in structure; since the variability is large, these may not be significant. Comparison of the measured and geostrophic average shears suggests there is a significant ageostrophic component in the upper layers above 40 m; it may be the signature of an average wind-driven Ekman spira Close

• 10. [Article] Enhanced southward flow over the Oregon shelf in 2002: a conduit for subarctic water

  Moored current measurements from the Oregon shelf during 1998–2003 are used to estimate time series of anomalous alongshore currents and pseudo-displacements, after accounting for the mean and seasonal ...

  Citation × Citation Citation Abstract Copy Title: Enhanced southward flow over the Oregon shelf in 2002: a conduit for subarctic water Author: Kosro, P. Michael, 1951- Moored current measurements from the Oregon shelf during 1998–2003 are used to estimate time series of anomalous alongshore currents and pseudo-displacements, after accounting for the mean and seasonal cycle. From early January through mid-June, 2002, currents at 10 m were anomalously strong toward the south by an average 12 cm/s, producing an anomalous displacement of more than 1500 km over about 5 months. This may be compared with the finding by Freeland et al. [2003] that waters at the same latitude off Oregon, and off Vancouver Island, were anomalously cool and fresh at depths between 30 and 150 m, suggesting displacement from a more northern source. Anomalous displacements of several hundred kilometers were also found during at least three other periods in the record. Moored temperature measurements at the same location confirm that local waters were persistently cooler during March to October of 2002 than during the previous two years, with the strongest anomaly near 20 m. Coastal sea levels were lower than usual along the northwest coast during spring and early summer 2002, consistent with a southward current anomaly of large scale. Local winds near Newport did not show strong mean anomalies during this period. Title: Enhanced southward flow over the Oregon shelf in 2002: a conduit for subarctic water Author: Kosro, P. Michael, 1951- Moored current measurements from the Oregon shelf during 1998–2003 are used to estimate time series of anomalous alongshore currents and pseudo-displacements, after accounting for the mean and seasonal cycle. From early January through mid-June, 2002, currents at 10 m were anomalously strong toward the south by an average 12 cm/s, producing an anomalous displacement of more than 1500 km over about 5 months. This may be compared with the finding by Freeland et al. [2003] that waters at the same latitude off Oregon, and off Vancouver Island, were anomalously cool and fresh at depths between 30 and 150 m, suggesting displacement from a more northern source. Anomalous displacements of several hundred kilometers were also found during at least three other periods in the record. Moored temperature measurements at the same location confirm that local waters were persistently cooler during March to October of 2002 than during the previous two years, with the strongest anomaly near 20 m. Coastal sea levels were lower than usual along the northwest coast during spring and early summer 2002, consistent with a southward current anomaly of large scale. Local winds near Newport did not show strong mean anomalies during this period. Close