Glider Observations of the Northwestern Iberian Margin During an Exceptional Summer Upwelling Season

Glider observations from the Northwestern Iberian Margin during the exceptionally strong 2010 summer upwelling season resolved the evolution of physical and biogeochemical variables during two upwelling events. Upwelling brought low-oxygen Eastern North Atlantic Central Water from 190 m depth onto the shelf up to a depth of 50 m. During the two observed periods of upwelling, a poleward jet developed over the shelf break. The persistent upwelling favorable winds maintained equatorward flow on the outer shelf for 2 months with no reversals during relaxation periods, a phenomenon not previously observed. During upwelling, near-surface chlorophyll a concentration increased by more than 6 mg m −3. Oxygen supersaturation in the near surface increased by more than 20%, 6 days after the chlorophyll a maximum

Remote sensing chlorophyll a of optically complex waters (rias Baixas, NW Spain): Application of a regionally specific chlorophyll a algorithm for MERIS full resolution data during an upwelling cycle

This study takes advantage of a regionally specific algorithm and the characteristics of Medium Resolution Imaging Spectrometer (MERIS) in order to deliver more accurate, detailed chlorophyll a (chla) maps of optically complex coastal waters during an upwelling cycle. MERIS full resolution chla concentrations and in situ data were obtained on the Galician (NW Spain) shelf and in three adjacent rias (embayments), sites of extensive mussel culture that experience frequent harmful algal events. Regionally focused algorithms (Regional neural network for rias Baixas or NNRB) for the retrieval of chla in the Galician rias optically complex waters were tested in comparison to sea-truth data. The one that showed the best performance was applied to a series of six MERIS (FR) images during a summer upwelling cycle to test its performance. The best performance parameters were given for the NN trained with high-quality data using the most abundant cluster found in the rias after the application of fuzzy c-mean clustering techniques (FCM). July 2008 was characterized by three periods of different meteorological and oceanographic states. The main changes in chla concentration and distribution were clearly captured in the images. After a period of strong upwelling favorable winds a high biomass algal event was recorded in the study area. However, MERIS missed the high chlorophyll upwelled water that was detected below surface in the ria de Vigo by the chla profiles, proving the necessity of in situ observations. Relatively high biomass “patches” were mapped in detail inside the rias. There was a significant variation in the timing and the extent of the maximum chla areas. The maps confirmed that the complex spatial structure of the phytoplankton distribution in the rias Baixas is affected by the surface currents and winds on the adjacent continental shelf. This study showed that a regionally specific algorithm for an ocean color sensor with the characteristics of MERIS in combination with in situ data can be of great help in chla monitoring, detection and study of high biomass algal events in an area affected by coastal upwelling such as the rias Baixas

Tide and wind coupling in a semienclosed bay driven by coastal upwelling

The Ría de Vigo is a semi-enclosed bay in which tidal residual currents are associated with coastal upwelling events. Both upwelling and downwelling favourable winds generate a bidirectional exchange flow with the shelf – a two-layer circulation with surface waters leaving (entering) the ria and a compensating inflow (outflow) through the bottom layer under upwelling (downwelling) conditions. This vertical circulation changes the vertical density structure inside the ria. In the ria, the tide is mainly semidiurnal (M2, S2 and K2), with some energy in the diurnal band (K1). Our velocity observations show that the vertical structure of the tidal currents in the ria do not exhibit a classic barotropic profile with a bottom boundary layer beneath uniform “free-stream” flow as the tidal bottom boundary layer is affected by stratification. This links tidal circulation to the wind-driven residual circulation, since the latter also greatly helps to control the stratification. We quantify this effect by fitting tidal ellipses to observed velocities through the water column. In addition to this indirect coupling through stratification, there is a direct interaction in which velocities in the upper and bottom layers are best correlated with winds while the mid-water velocities are best correlated with tides. These wind-tide interactions are expected to play a key role in the resuspension and transport of nutrients and phytoplankton in the Ria.CTM2012-3515

An Equity-focused Assessment of the City of Richmond’s RVAgreen 2050 Planning Process

Local climate action and sustainability initiatives are often critiqued for their inattention to issues of equity and justice. In response, an increasing number of cities are now attempting to respond to this critique by making equity a more explicit goal of their climate action plans: Richmond Virginia is among those cities. The City of Richmond\u27s Office of Sustainability committed to prioritizing equity in the RVAGreen 2050 plan by recognizing how Richmond’s history of racism and structural inequalities have exacerbated climate concerns for largely Black and Latinx communities and centering historically marginalized communities of color in the engagement process. Students in URSP 637 Sustainable Community Development were asked to provide an external evaluation of the RVAGreen 2050 planning process. This report summarizes the findings of this evaluation and highlights recommendations for how to improve equity-centered engagement processed moving forward

High-resolution measurements of an upwelling filament during the CAIBEX survey

Upwelling filaments have been studied for several years. We aim to explain the general process in terms of potential vorticity: An injection of positive vorticity north of the Cape forces the jet to turn offshore, in virtue of the principle of vorticity conservation. The Regional Ocean Modeling System (ROMS) is implemented in the Cape Ghir region, with horizontal resolution lower than 1 km. A set of process-oriented experiments has been designed in order to determine the mechanisms at the origin of the filament.CAIBE

Poleward front of upwelling filaments generates subsurface anticyclonic eddies (FEDDY): a CAIBEX Project contribution

CAIBE

Correction: Transient response of the Northwestern Iberian upwelling regime.

[This corrects the article DOI: 10.1371/journal.pone.0197627.]

Modeling and observation of an upwelling filament off Cape Ghir (NW~Africa) during the CAIBEX campaign

CAIBE

Upwelling filaments: a view through 3 different eyes

CAIBE