Seasonal fluctuations of temperature, salinity, nitrate, chlorophyll and primary production at station H3/M1 over 1989-1996 in Monterey Bay, California

Abstract Time series of temperature, salinity, nitrate, primary production and chlorophyll over 1989–1996 at station H3/M1 in central Monterey Bay, CA, USA, are described, and an `average year’ is calculated for each parameter. Surface spatial data on temperature, salinity, chlorophyll and primary production from spring and fall 1993 also are presented. Surface water (0–5 m) was coldest and saltiest in spring (∼10–11°C; S =33.4–33.8), warmed during summer (∼14°C), remained warm but freshened in fall ( S =33.3–33.4), and cooled and freshened further in winter (∼13°C; S =32.9–33.3). Nitrate time series show high concentrations (10–20 μM) present at the surface during spring and summer; low concentrations ( 100 mg C m −3  da −1 ) occurred in upper 20 m of the water column, while high chlorophyll (>3 mg m −3 ) extended to 25–30 m. Phytoplankton blooms occurred as pulses of primary production and chlorophyll during spring, summer and occasionally in fall. Springtime spatial data show a surface `plume’ of cold, salty, low chlorophyll and low primary production water extending N–S across the mouth of the Monterey Bay. The time-series station H3/M1 lies in the path of this plume. High chlorophyll and productivity values occur on the margins of the plume. Fall spatial data show temperatures and salinities warmer and fresher than spring while chlorophyll and primary production values were low. There was less spatial variability in fall. A temperature/salinity time series for Monterey Bay from 1951 to 1991 ( Kuo, 1991 ) shows similar seasonal patterns. However, the 1989–1996 time series is warmer and fresher to at least 100 m, particularly during non-upwelling seasons, and shows a later onset of upwelling. These differences are in accord with the `regime shift’ associated changes documented for the California Current by other workers. Long-term climatologies for nitrate, chlorophyll and primary production are not available for comparison with the data presented in this paper.

[1]  Franklin B. Schwing,et al.  Bifurcated flow from an upwelling center: a cold water source for Monterey Bay , 1994 .

[2]  L. C. Breaker,et al.  The circulation of Monterey Bay and related processes , 1989 .

[3]  A Bakun,et al.  Global Climate Change and Intensification of Coastal Ocean Upwelling , 1990, Science.

[4]  J. Mcgowan,et al.  PLANKTON PATTERNS, CLIMATE, AND CHANGE IN THE CALIFORNIA CURRENT , 1996 .

[5]  G. Friederich,et al.  MBARI procedures for automated nutrient analyses using a modified Alpkem Series 300 Rapid Flow Analyzer , 1990 .

[6]  C. Lorenzen,et al.  Fluorometric Determination of Chlorophyll , 1965 .

[7]  R. Kudela,et al.  Nutrient regulation of phytoplankton productivity in Monterey Bay , 2000 .

[8]  U. Send,et al.  Relaxation from upwelling in the Coastal Ocean Dynamics Experiment , 1987 .

[9]  A. Longhurst.  Analysis of Marine Ecosystems , 1981 .

[10]  D. Cayan,et al.  Climate-Ocean Variability and Ecosystem Response in the Northeast Pacific , 1998, Science.

[11]  E. Duursma.  Productivity of the ocean: Present and past: Edited by W.H. Berger, V.S. Smetacek and G. Wefer. John Wiley & Sons, Chichester, UK 1989. A Dahlem Workshop Report, Life Sciences Research Rep. 44. xiii + 471 pp. ISBN 0-471-92246-3 , 1992 .

[12]  D. Garrison.  Monterey Bay phytoplankton I. Seasonal cycles of phytoplankton assemblages , 1979 .

[13]  R. L. Smith,et al.  Coastal upwelling ecosystems , 1981 .

[14]  N. Garfield,et al.  Mean structure of the inshore countercurrent and California undercurrent off Point Sur, California , 2000 .

[15]  C. Summerhayes.  Upwelling in the Ocean , 1984 .

[16]  A. Huyer,et al.  Mesoscale surveys over the shelf and slope in the upwelling region near Point Arena, California , 1987 .

[17]  R. Kudela,et al.  Carbon and nitrogen uptake response to light by phytoplankton during an upwelling event , 1997 .

[18]  David M. Karl,et al.  Freezing as a method of sample preservation for the analysis of dissolved inorganic nutrients in seawater , 1996 .

[19]  M. Abbott,et al.  Satellite observations of phytoplankton variability during an upwelling event , 1985 .

[20]  S. Manabe,et al.  Model assessment of decadal variability and trends in the tropical Pacific Ocean , 1998 .

[21]  Kathryn A. Kelly,et al.  The influence of winds and topography on the sea surface temperature patterns over the northern California slope , 1985 .

[22]  Francisco P. Chavez,et al.  Relationship between physical and biological variables during the upwelling period in Monterey Bay, CA , 1998 .

[23]  Timothy J. Hoar,et al.  The 1990–1995 El Niño‐Southern Oscillation Event: Longest on Record , 1996 .

[24]  Steven R. Hare,et al.  Decadal-scale regime shifts in the large marine ecosystems of the North-east Pacific: a case for historical science , 1994 .

[25]  C. Mooers,et al.  Oceanic variability off the Central California coast , 1986 .

[26]  David H. Thomas.  YEAR-TO-YEAR FLUCTUATIONS OF THE CALIFORNIA COUNTERCURRENT AND EFFECTS ON MARINE ORGANISMS , 1983 .

[27]  Steven R. Hare,et al.  Inverse Production Regimes: Alaska and West Coast Pacific Salmon , 1999 .

[28]  W. M. Graham.  Spatio-temporal scale assessment of an “upwelling shadow” in Northern Monterey Bay, California , 1993 .

[29]  D. Halpern.  Structure of a coastal upwelling event observed off Oregon during July 1973 , 1976 .

[30]  F. Chavez.  Forcing and biological impact of onset of the 1992 El Niño in central California , 1996 .

[31]  J. Wallace,et al.  A Pacific Interdecadal Climate Oscillation with Impacts on Salmon Production , 1997 .

[32]  K. Brink.  The near-surface dynamics of coastal upwelling , 1983 .

[33]  Dean Roemmich,et al.  Climatic Warming and the Decline of Zooplankton in the California Current , 1995, Science.

[34]  F. Chavez,et al.  Modeling the impact of the 1992 El Niño on new production in Monterey Bay, California , 2000 .

[35]  Adriana Huyer,et al.  The nature of the cold filaments in the California Current system , 1991 .

[36]  M. Latif,et al.  Greenhouse Warming, Decadal Variability, or El Niño? An Attempt to Understand the Anomalous 1990s , 1997 .

[37]  F. Chavez,et al.  Suspended particulate nitrogen δ15N versus nitrate utilization: observations in Monterey Bay, CA , 1998 .

[38]  Robert L. Smith,et al.  The structure of the transition zone between coastal waters and the open ocean off northern California, winter and spring 1987 , 1991 .

[39]  Robert L. Smith,et al.  Large-scale structure of the spring transition in the coastal ocean off western North America , 1987 .

[40]  Nicholas E. Graham,et al.  The 1976-77 Climate Shift of the Pacific Ocean , 1994 .

[41]  J. McClean,et al.  Observations and modeling of the 1991–1992 El Niño signal off central California , 1997 .

[42]  Francisco P. Chavez,et al.  A model of plankton dynamics for the coastal upwelling system of Monterey Bay , 2000 .

[43]  F. Chavez,et al.  Horizontal transport and the distribution of nutrients in the coastal transition zone off Northern California: effects on primary production, phytoplankton biomass and species composition , 1991 .

[44]  Francisco P. Chavez,et al.  Moorings and Drifters for Real-Time Interdisciplinary Oceanography , 1997 .

[45]  James J. Simpson,et al.  The California Current system: The seasonal variability of its physical characteristics , 1987 .

[46]  A. Huyer.  Coastal Upwelling in the California Current System , 1983 .

[47]  R. Davis,et al.  Moored wind, temperature, and current observations made during Coastal Ocean Dynamics Experiments 1 and 2 over the Northern California Continental Shelf and upper slope , 1987 .

[48]  Barbara M. Hickey,et al.  The California current system—hypotheses and facts☆ , 1979 .

[49]  D. Roemmich.  Ocean Warming and Sea Level Rise Along the Southwest U.S. Coast , 1992, Science.

[50]  T. Hayward,et al.  Pacific Ocean climate change: atmospheric forcing, ocean circulation and ecosystem response. , 1997, Trends in ecology & evolution.

[51]  W. Large,et al.  Open Ocean Momentum Flux Measurements in Moderate to Strong Winds , 1981 .

[52]  Timothy R. Parsons,et al.  A manual of chemical and biological methods for seawater analysis , 1984 .

[53]  Jeffrey D. Paduan,et al.  Remotely sensed surface currents in Monterey Bay from shore-based HF radar (Coastal Ocean Dynamics Application Radar) , 1996 .

[54]  F. Chavez,et al.  Autecology of the diatom Pseudonitzschia australis, a domoic acid producer, from Monterey Bay, California , 1992 .

[55]  W. Smethie.  Some aspects of the temperature, oxygen and nutrient distributions in Monterey Bay, California. Annual Report, Part 1, 1973 , 1973 .

[56]  J. G. Field,et al.  Persistent “upwelling shadows” and their influence on zooplankton distributions , 1992 .

[57]  F. Chavez,et al.  EXPLORATIONS OF EL NINO EVENTS AND ASSOCIATED BIOLOGICAL POPULATION DYNAMICS OFF CENTRAL CALIFORNIA , 1995 .

[58]  Robert L. Smith,et al.  Seasonal cycles of currents, temperatures, winds, and sea level over the northeast pacific continental shelf: 35°N to 48°N , 1987 .

[59]  W. Broenkow,et al.  Surface circulation and replacement of water in Monterey Bay , 1978 .