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Abstract Anthropogenic input of carbon dioxide (CO 2) into the atmosphere and its uptake by the ocean with associated changes in ocean chemistry have created an urgent need to expand coverage of sea surface and atmospheric carbon dioxide observations. Conventional sampling platforms (e.g. ships and moorings) do not provide the spatial and temporal resolution needed to assess the effects of rapidly changing carbon dioxide conditions and are expensive to operate. Through a series of deployments beginning in March 2012, two versions of the Wave Glider autonomous surface vehicles from Liquid Robotics, Inc. have been instrumented with sensors to measure pH, partial pressure of CO 2 (p CO 2) of the atmosphere and sea surface, and wind speed and direction, from which instantaneous sea-air fluxes of CO 2 can be calculated. These deployments, most near Monterey Bay, California, were highly correlated with Δ p CO 2 measurements obtained from the Monterey Bay Aquarium Research Institute's (MBARI) long-term mooring station M1, as well as from shipboard observations. In the central California upwelling system with highly variable p CO 2 levels, the gliders captured large spatial gradients associated with upwelling fronts. Differences in sea surface p CO 2 as large as 470 μ atm over < 0.5 km were observed. Unlike traditional ship sampling methods, however, this new generation of sampling platforms is capable of continuous long-term (months) deployments at a fraction of the cost. The vehicles thus have the potential of filling important gaps in present understanding of the effects of global change on ocean chemistry. [ABSTRACT FROM AUTHOR]

Abstract Monterey Bay, California, has been sampled by ship at 2–3 week intervals during 1989–2011. Here we present the resulting time series of temperature, salinity, nitrate, chlorophyll and primary production over the 23-year record and correlate the nonseasonal anomalies and four Pacific Basin-scale climate indices. About half of Monterey Bay variability was captured by the seasonal cycle while half remained in the anomalies. Correlations revealed strong associations between temperature, salinity and nitrate, and weaker correlations between these anomalies and euphotic zone-integrated chlorophyll and primary production. Sub-euphotic zone physical and particularly nitrate anomalies were better predictors of the euphotic zone biological variables than were their surface anomalies. The strongest correlations between temperature, salinity and nitrate anomalies occurred in spring and summer (e.g. during upwelling). Conversely, spring and summer nitrate were less well correlated with the biological variables than during the remaining months due to nonlinearity in the biological response. Lagged cross-correlations generally showed decreasing correlation with increasing lag (0–12 months). The Monterey Bay anomalies were then correlated with four Pacific Basin-scale climate indices --- the Multivariate ENSO Index (MEI), the Pacific Decadal Oscillation (PDO), the El Niño Modoki Index (EMI), and the North Pacific Gyre Oscillation (NPGO). Temperature, salinity and nitrate were well-correlated to the indices (accounted for 20–25% of the variance) whereas chlorophyll and primary production were weakly- and often insignificantly-correlated with the indices (accounted for 4–10% of the variance). The MEI was most strongly and the EMI least strongly (usually insignificantly) correlated with the anomalies. Most indices were also significantly cross-correlated over the observation period. Seasonally, the MEI produced strong winter and weaker summer associations with temperature, salinity and nitrate, and weak negative correlations with the biological anomalies all year. The PDO showed similar but weaker associations. The EMI correlations were weak but revealed seasonal cycles similar in phasing to those of the MEI. The NPGO exhibited positive relationships with salinity, nitrate and the biological anomalies, all peaking in summer and fall, and a weak negative association with temperature. Index-leads-anomaly correlations did not generally strengthen with lag (0–12 months). All the anomalies exhibited trends, with temperature decreasing and salinity, nitrate and the biological anomalies increasing. Except for 200 m temperature, these trends were significant and substantial, with surface nitrate and euphotic-zone integrated chlorophyll and primary production increasing 1.69 uM, 7.27 mg m−2 and 510 mgC m−2 d−1 per decade, respectively. These Monterey Bay trends are consistent with other California Current results and Pacific Basin index trends over the same period, indicating that Monterey Bay fluctuates with the California Current and North Pacific Basin. [ABSTRACT FROM AUTHOR]

Abstract Sediment traps were deployed at two depths (300 m and 1200 m) off Monterey Bay (36°40′N and 122°25′W, Central California) for 7.3 years (1998–2005). The sediment trap data provided information about the quantity and quality of settling material, and allowed exploration of the relationship of the sinking material with the environmental conditions in this coastal upwelling region. The magnitude and composition of the settling material were highly variable over time. Organic carbon (C org) fluxes ranged between 4–296 mg C m−2 day−1 and 0.1–142 mg C m−2 day−1 for shallow and deep sediment traps, respectively. The time series of C org vertical flux was characterized by pulses of intense fluxes that were associated with peaks of primary production, generally during upwelling periods. Despite considerable variability, fluxes varied seasonally with highest values during the upwelling season and the lowest in winter. Attenuation of C org vertical fluxes with depth (300 m vs. 1200 m) varied between 31% and 24% except for the late upwelling period, when there was an increase with depth likely due to resuspension of material from Monterey Canyon. Calculation of a seasonal vertical budget of organic carbon off Monterey Bay resulted in a transfer between 4.0% and 4.9% of the primary production to the deep ocean, suggesting that coastal upwelling efficiently sequestered CO 2. [ABSTRACT FROM AUTHOR]

Abstract: The introduction of the SeaWiFS ocean-color instrument in the autumn of 1997 coincided with the onset of perhaps the largest El Niño event of the century, providing us with the opportunity to monitor the impact of such events on biological and bio-optical properties in central California. The increased importance of coastal runoff (both sediments and fresh water) during the winter of 1998 have been striking. Here we evaluate the effects of riverine input to central California immediately following the largest El Niño-influenced winter storm event in central California of February 1998 using shipboard, mooring, and satellite observations from the sea-viewing wide field-of-view sensor (SeaWiFS). Two models were employed to estimate colored dissolved organic matter, (CDOM), which provided similar spatial and temporal patterns of CDOM, but differing absolute concentrations. We observed a 5-fold increase in SeaWiFS-derived chlorophyll concentrations, with a corresponding CDOM signal (estimated absorption at 300nm greater than 0.30m−1) extending to approximately 300km offshore. This event, while anomalous, demonstrates the potential influence of riverine input on the bio-optical properties of the coastal environment extending to several hundred kilometers offshore. [Copyright &y& Elsevier]

Provides information on a study which applied a modified plankton model to the coastal upwelling ecosystem of Monterey Bay, California. Environmental setting; Details on the model; Results of the study.

Provides information on a study which estimated primary production using phytoplankton utilization of nitrate for the Monterey Bay, California region. Model description; Results and discussion.

Provides information on a study which described time series of temperature, salinity, nitrate, primary production and chlorophyll in a station in Monterey Bay, California. Methods of the study; Results and discussion.

Editorial. Introduces a series of articles which dealt with the California Current System (CCS).

Abstract: On two cruises in August and September 2003 (hereafter cruises 2 and 3) during wind relaxations and transitions to upwelling conditions, thin layers of phytoplankton were observed in or a few meters below the stratified transition layer at the mixed layer base and in regions of sheared flow on the flanks of eddies, filaments, and fronts near Monterey Bay, California. On an earlier cruise in August (cruise 1), no thin layers were found after a prolonged wind relaxation. Chlorophyll concentrations and shear were both an order of magnitude less than on cruises 2 and 3. Our vertical profiles were made using a fluorometer mounted on a conductivity–temperature–depth package, which was lowered from the ship as slowly as every 10km on five cross-shore transects. Remotely sensed sea-surface temperature, chlorophyll, and currents are required to understand the temporal and spatial evolution of the circulation and to interpret the quasi-synoptic in situ data. Decorrelation scales are from lagged temperature and salinity covariances. Objectively mapped sections of the in situ data indicate the waters containing thin layers were recently upwelled at either the Point Sur or Point Año Nuevo upwelling centers. Spatially limited distributions of phytoplankton at the coastal upwelling centers ( alongshore, 20km cross-shore, and 30m thick) were transformed into thin layers by current shear and isolated from wind-driven vertical mixing by the stratification maximum of the transition layer. Vertically sheared horizontal currents on the flanks of the eddies, filaments, and fronts horizontally stretched and vertically thinned phytoplankton distributions. These thin, elongated structures were then observed as thin layers of phytoplankton in vertical fluorescence profiles at four stations on cruise 2 and eight stations on cruise 3. Light winds during relaxations did not mix away these thin layers. On cruise 2, thin layers were found at eddies at the inshore and offshore ends of a 100-km-long filament, while broader subsurface chlorophyll maxima were found along the filament. This result suggests that higher-resolution sampling along and across a filament may find thin layers forming and dissipating along its length. On cruise 3, thin layers were found at three adjacent stations across an upwelling front and may have extended continuously for , but neither species composition nor bio-optical data are available to confirm this conjecture. The thin layers were 1–5m thick in the vertical at full width half maximum and had peak fluorescence values from . (Bottle chlorophyll samples showed fluorometer chlorophyll readings may have been large, but the scatter in this relation was considerable especially at the larger fluorescence values detected in thin layers.) While sheared currents thinned an initially thick subsurface chlorophyll maximum into thin layers, the peak values in these thin layers exceeded concentrations in the upwelled source waters and were unexplained by our data. [Copyright &y& Elsevier]

Abstract: This paper investigates the transport structure of surface currents around the Monterey Bay, CA region. Currents measured by radar stations around Monterey Bay indicate the presence of strong, spatial and temporal, nonlinear patterns. To understand the geometry of the flow in the bay, Lagrangian coherent structures (LCS) are computed. These structures are mobile separatrices that divide the flow into regions of qualitatively different dynamics. They provide direct information about the flow structure but are geometrically simpler than particle trajectories themselves. The LCS patterns were used to reveal the mesoscale flow conditions observed during the 2003 Autonomous Ocean Sampling Network (AOSN-II) experiment. Drifter paths from the AOSN experiment were compared to the patterns induced by the LCS computed from high-frequency radar data. We verify that the fate of the drifters can be better characterized based on the LCS than direct interpretation of the current data. This property can be exploited to optimize drifter deployment. [Copyright &y& Elsevier]