“Interpretation of the June 2008 conditions along California Cooperative Oceanic Fisheries Investigations (CalCOFI) Line-67 by using Climatology” One picture 1000 words… Presented by: Alevras Dimitris

Outline ♦ Introduction ♦ Methods / Cruise Data ♦ Climate Conditions ♦ Cruise Results / Discussion ♦ Conclusions

♦ Before the goal was achieved, however, the sardines vanished Introduction ♦ In the late 1940s following heavy fishing during WW II, sardine landings in CA were declining and the - California Division of Fish and Game, - California Academy of the Sciences, - Scripps Institute of Oceanography and the - U.S. Fish and Wildlife Service joined forces to develop the California Cooperative Sardine Research Program. ♦ The goal was to understand the physical and biological components of the marine ecosystem as they affected sardine stocks. ♦ Before the goal was achieved, however, the sardines vanished ♦ In 1953 the program was scaled-back and renamed the “California Cooperative Oceanic Fisheries Investigations” (CalCOFI) program

Introduction ♦ The “California Cooperative Oceanic Fisheries Investigations” (CalCOFI) program conducts quarterly survey cruises on a fixed station grid ♦ CalCOFI Line 67

Introduction 14 13 12 1 1 3 2 2 3 4 5 4 6 7 8 5 9 6 10 7 11 CTD XBT

Methods / Data ♦ Data: ♦ Plots: ♦ Methods: (1) Wind field data (Speed / Direction) (2) CTD and ADCP data acquired along CalCOFI Line-67 aboard the R/V POINT SUR (3) Climatology data from NOAA & PACific Ocean Observing System ♦ Plots: Wind field plots (Speed/ Direction) (2) T-S Diagrams (3) Diagrams of Salinity & Temperature by using Principal Component Analysis (PCA) (or Proper Orthogonal Decomposition (POD)). (4) Geostrophic Velocity plots (5) Plots of Density Anomaly – Temperature – Salinity – Dissolved Oxygen Distributions ♦ Methods: (1) Data were acquired at each station using a Sea-Bird Electronics, Inc.CTD, which provided continuous measurements of conductivity (salinity), temperature and pressure. (2) MATLAB functions for the above plots were created by the Oceanography Department of NPS

♦ Temperature and Salinity: Climate Conditions ♦ Temperature and Salinity: Temperature and salinity through June 08 was colder than any summer since CTD data collection began in 1997; given the strong winds observed, we had one of the coldest summer since at least 1997 ♦ Upwelling Index (UI): The monthly coastal upwelling index showed upwelling favorable conditions between 24°- 42°N ♦ El Nino Southern Oscillation (ENSO): A transition period from La Nina to ENSO during June 2008 - neutral conditions

Climate Conditions – Temperature & Salinity T – S Diagram at Newport, Oregon Jun 2008 ♦ Temperature at the M1 Mooring, Monterey Bay during last June was very cold ♦ Temperature and salinity through June 08 averages 7.31 and 33.91 respectively which is colder than any summer since the group began taking CTD data in 1997

Climate Conditions – Temperature & Salinity

Climate Conditions – Upwelling Index (UI) ♦ - Solid black lines denote the daily UI - Dashed curve is a biharmonic fit to the daily UIs for 1967-1991 - Blue shaded area denotes one standard error - Yellow bars denote monthly mean of UI based on the daily values. - Units are metric tons / sec / 100 m of coastline OR cubic meters / sec / 100 m of coastline ♦ Strong southeastward, upwelling favorable, wind stress occurred along the coast in the area of interest.

Climate Conditions – El Nino Southern Oscillation (ENSO) Upper-Ocean Conditions in the Equatorial Pacific Oceanic Nino Index vs. time Upper-Ocean Heat Anomaly (in degrees C) Thermocline Slope Index (in m) ♦ Oceanic Niño Index (ONI) is based on SST departures from average in the Niño 3.4 region, and is a principal measure for monitoring, assessing, and predicting ENSO ♦ The monthly thermocline slope index represents the difference in anomalous depth of the 20ºC isotherm between the W Pacific and the E Pacific

Climate Conditions – El Nino Southern Oscillation (ENSO) Upper-Ocean Conditions in the Equatorial Pacific ♦ NOAA Operational Definitions for El Niño and La Niña El Niño: positive ONI greater than or equal to +0.5°C La Niña: negative ONI less than or equal to -0.5°C

Climate Conditions – El Nino Southern Oscillation (ENSO) Upper-Ocean Conditions in the Equatorial Pacific ♦ By comparing top 2 panels we can observe: - heat anomalies are greater prior to and during the early stages of a Pacific warm (El Niño) episode - heat anomalies are least prior to and during the early stages of a cold (La Niña) episode

Climate Conditions – El Nino Southern Oscillation (ENSO) Upper-Ocean Conditions in the Equatorial Pacific ♦ By comparing the first and the third panels we can observe: - The slope of the oceanic thermocline is least during warm episodes - The slope of the oceanic thermocline is greatest during cold episodes

Climate Conditions – El Nino Southern Oscillation (ENSO) Upper-Ocean Conditions in the Equatorial Pacific ♦ Current values of the upper- ocean heat anomalies (slightly positive) and the thermocline slope index (near zero) indicate ENSO-neutral conditions

Cruise Results – Winds Data ♦ The strong SEward winds are consistent with the climate conditions (Strong SEward, upwelling favorable, wind stress)

Cruise Results – Temperature / Salinity Principal component analysis (PCA) or proper orthogonal decomposition (POD). Salinity first & second principal components ♦ Sal.: 61.5% Temp.: 64.9% ♦ The PC amplitudes are consistent with the climate conditions (one of the coldest summer) Temperature first & second principal components

Cruise Results – Geostrophic Velocity ♦ By using the following relations we evaluate the geostrophic velocity: L: is the distance between CTD stations δ: is the specific volume anomaly ΔΦ: is the geopotential anomaly CC ♦ Red region: California Under Current (CUC) Blue region: California Current (CC) CUC ♦ The geostrophic velocity plot is consistent with the climate conditions (Strong Upwelling) but the location of the California Current is closer to the shore)

Cruise Results – T-S Diagrams ♦ Cooler, saline, surface water most likely associated with coastal upwelling ♦ The equatorward flow of cool, fresh, arctic waters characterizes the California Current ♦ There is a distinct separation between two water masses. The cool, fresher waters of the California Current can be distinguished from the warmer, saline waters of the California Undercurrent. This separation becomes apparent below ~100 dbar (or ~100 C).

Cruise Results – Temperature / Salinity Anomalies ♦ Cooler, saline, surface water most likely associated with coastal upwelling ♦ The equatorward flow of cool, fresh, arctic waters characterizes the CC ♦ Well mixing conditions due to the strong winds ♦ All plots are consistent with the climate conditions (Strong Upwelling) ♦ The location of the CC is closer to the shore

Cruise Results – Dens. Anom. / Dissolved Ox. / Salinity / Temp Deep water measurements Shallow water measurements ♦ Cooler, saline, surface water most likely associated with coastal upwelling ♦ The equatorward flow of cool, fresh, arctic waters characterizes the CC ♦ Well mixing conditions due to the strong winds ♦ All plots are consistent with the climate conditions (Strong Upwelling) ♦ The location of the CC is closer to the shore

Conclusions ♦ The CTD data and the geostrophic velocity field were in general agreement ♦ All cruise data showed that due to the strong winds, we had well mixing conditions and one of the coldest summer ♦ The location of the California Current and the California Under Current was evident at cruise data ♦ All cruise data were in agreement that we had upwelling favorable conditions ♦ With the exception of the cold SST and the location of the CC, generally, the cruise data were consistent with the Climate Conditions.

Bibliography ♦ Collins, C.A., R.G. Paquette and S.R. Ramp, 1996b. Annual Variability of ocean currents at 350 m depth over the continental slope off Point Sur, California. CalCOFI rep., 37, 257-263. ♦ Hickey, B., .Coastal Oceanography of Western North America from the Tip of Baja California to Vancouver Island; Coastal Segment. in The Sea, Robinson, A.R., and Brink, K. H., pp 12,947-12,966, 1998. ♦ Graphs of Upwelling Indices over the last 18 months (http://www.pfel.noaa.gov/ products/PFEL/modeled/indices/upwelling/NA/daily_upwell_graphs.html) ♦ Lynn, R.J., and J.J. Simpson, 1987. The California Current System: The seasonal variability of its physical characteristics, J. Geophys. Res., 92, 12,947-12,966 ♦ Neander D.O. (LCDR, NOAA), 2001The California Current System: Comparison of Geostrophic Currents, ADCP Currents and Satellite Altimetry ♦ Pacific Coast Ocean Observing System,2008/Climatic and Ecological Conditions in the California Current LME for April to June 2008 / (http://pacoos.org/QuarterlyUpdate_Climatic/AprMayJun08.pdf) ♦ Pennington J.T., Michisaki R., Johnston D., Chavez F.P., Ocean observing in the Monterey Bay National Marine Sanctuary: CalCOFI and the MBARI time series A Report to the Sanctuary Integrated Monitoring Network (SIMoN), March 7, 2007 ♦ Pickard, G.L., and W.J. Emery, 1982. Descriptive Physical Oceanography; An Introduction, 5th Ed., pp 64-65, Butterworth/Heinemann.

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