Carlos Moffat

University of Delaware | UDel UD · School of Marine Science and Policy

We present hydrographic and shipboard ADCP data collected during the fall (April/June) and winter (July/August) and moored velocity observations collected from 2001 to early 2002 on the west Antarctic Peninsula (wAP) shelf during the Southern Ocean Global Ecosystems Dynamics (SO GLOBEC) program. In fall, a geostrophically balanced, buoyant current...

Here, the response of a coastally trapped buoyant plume to downwelling-favorable wind forcing is explored using a simplified two-dimensional numerical model and a prognostic theory for the resulting width, depth, and density anomaly and along-shelf transport of the plume. Consistent with the numerical simulations, the analytical model shows that th...

Projections of sea level rise due to ice loss from the land to the ocean have been hampered by a lack of understanding of the role the ocean is playing in glacier retreat, including the processes that contribute to the supply of warm water to the ice-ocean interface. Here shipboard, moored, and weather station data collected off Jorge Montt, a rapi...

The West Antarctic Peninsula (WAP) is a highly productive marine ecosystem where extended periods of change have been observed in the form of glacier retreat, reduction of sea-ice cover and shifts in marine populations, among others. The physical environment on the shelf is known to be strongly influenced by the Antarctic Circumpolar Current flowin...

The west Antarctic Peninsula (WAP) region has undergone significant changes in temperature and seasonal ice dynamics since the mid-twentieth century, with strong impacts on the regional ecosystem, ocean chemistry and hydrographic properties. Changes to these long-term trends of warming and sea ice decline have been observed in the 21st century, but...

Abstract Climate change is leading to phenological shifts across a wide range of species globally. Polar oceans are hotspots of rapid climate change where sea ice dynamics structure ecosystems and organismal life cycles are attuned to ice seasonality. To anticipate climate change impacts on populations and ecosystem services, it is critical to unde...

The continental shelf of the West Antarctic Peninsula (WAP) is characterized by strong along-shore hydrographic gradients resulting from the distinct influences of the warm Bellingshausen Sea to the south and the cold Weddell Sea water flooding Bransfield Strait to the north. These gradients modulate the spatial structure of glacier retreat and are...

Palmer Deep Canyon is one of the biological hotspots associated with deep bathymetric features along the West Antarctic Peninsula. The upwelling of nutrient‐rich Upper Circumpolar Deep Water to the surface mixed layer in the submarine canyon has been hypothesized to drive increased phytoplankton biomass, attracting krill, penguins and other top pre...

Physical scientists, social scientists, humanities scholars, and journalists have all framed Antarctica as a place of global importance—as a laboratory for scientific research, as a strategic site for geopolitical agendas, and more recently as a source of melting ice that could catastrophically inundate populations worldwide. Yet, the changing cryo...

The manuscript assesses the current and expected future global drivers of Southern Ocean (SO) ecosystems. Atmospheric ozone depletion over the Antarctic since the 1970s, has been a key driver, resulting in springtime cooling of the stratosphere and intensification of the polar vortex, increasing the frequency of positive phases of the Southern Annu...

Coastal salt marshes store large amounts of carbon but the magnitude and patterns of greenhouse gas (GHG; i.e., carbon dioxide (CO2) and methane (CH4)) fluxes are unclear. Information about GHG fluxes from these ecosystems comes from studies of sediments or at the ecosystem-scale (eddy covariance) but fluxes from tidal creeks are unknown. We measur...

The pelagic Southern Ocean is a high‐nutrient, low‐chlorophyll ecosystem. Here, phytoplankton growth is colimited by iron supply and light availability. This creates a general expectation that when light is available in the austral summer (shallow mixing depths), phytoplankton concentrations may be high or low depending on the delivery of iron to t...

Oceanic heat strongly influences the glaciers and ice shelves along West Antarctica. Prior studies show that the subsurface onshore heat flux from the Southern Ocean on the shelf occurs through deep, glacially carved channels. The mechanisms enabling the export of colder shelf waters to the open ocean, however, have not been determined. Here, we us...

This is the second version of a bathymetric map of the Baker-Martinez fjord system (Chile, 48°S) constructed from multiple datasets: multibeam echosounder data of Baker channel (Harada et al., 2008) and of Steffen fjord and Baker river delta (Vandekerkhove et al., in press), single beam echosounder data of Martinez channel (R/V Sur-Austral 2015/201...

The Southern Patagonia Icefield (SPI) withdrawal in recent decades shows contrasting behaviours between adjacent basins. One of the basins with highest volumetric losses is located at northern- most SPI. We refer to Jorge Montt tidewater glacier (48° 30′S/73° 30′W, 445 km2 in 2018), which retreated 2.7 km between 2011 and 2018 and thinned at rates...

Proglacial fjords are critical conduits for the exchange of heat and freshwater between the ocean and land ice, and their dynamics heavily modulate the rate of retreat of tidewater glaciers. Here, the magnitude, spatial structure, and seasonal evolution of the ocean forcing on the proglacial fjord off a rapidly retreating glacier (Jorge Montt, Pata...

The map is available here in 3 different formats: https://doi.org/10.6084/m9.figshare.5285521.v3 We present a bathymetric map of the Baker-Martinez fjord complex (Chile, 48⁰S) constructed from multiple data sets: multibeam echosounder data of Baker channel (Harada et al., 2008) and of Steffen fjord and Baker river delta (Vandekerkhove & Bertrand,...

Submarine canyons cutting across the continental shelf can modulate the cross-shelf circulation being effective pathways to bring water from the deep ocean onto the shelf. Here, we use 69 days of moored array observations of temperature and ocean currents collected during the spring of 2013 and winter-spring 2014, as well as shipboard hydrographic...

Jorge Montt glacier, located in the Patagonian Ice Fields, has undergone an unprecedented retreat during the past century. To study the impact of the meltwater discharge on the microbial community of the downstream fjord, we targeted Bacteria, Archaea and Fungi communities during austral autumn and winter. Our results showed a singular microbial co...

A number of studies have posited that coastally generated eddies could cool the southeast Pacific Ocean (SEP) by advecting cool, upwelled waters offshore. We examine this mechanism by characterizing the upper-ocean properties of mesoscale eddies in the SEP with a variety of observations and by estimating the surface-layer eddy heat flux divergence...

As part of the VAMOS Ocean-Cloud-Atmosphere-Land Study (VOCALS) Regional Experiment, properties of upper-ocean turbulence were measured with a microstructure profiler during ship-based surveys, and a longer time series of turbulent kinetic energy dissipation at 9-m depth was collected from a surface mooring. The ship-based surveys allow examination...

We characterize the response of diurnal-period ocean current variability to the sea breeze using measurements of current velocity taken off the mouth of the Itata River and wind stress collected at Hualpen Point (central Chile) in spring of 2007 and summer of 2006 and 2008. During these three periods, the winds are predominately towards the northea...

As part of the VAMOS Ocean-Cloud-Atmosphere-Land Study (VOCALS) Regional Experiment, properties of upper-ocean turbulence were observed with a year-long time series of turbulent kinetic energy dissipation at 9-m depth collected from a surface mooring and with a microstructure profiler during month-long ship-based surveys. In this VOCALS region, a r...

The Southeast Pacific is a region characterized by a persistent stratocumulus cloud deck and a cold sea surface temperature (SST) anomaly that extends far beyond the region of upwelling at the coast. Climate models typically fail to reproduce the observed SST suggesting that oceanic processes which contribute to cooling the region are not adequatel...

Persistent stratus clouds extend over a broad region off Peru and northern Chile. The determination of the processes that govern the heat budget of the upper ocean and the sea surface temperature (SST) under these stratus has been a challenge, due in large part to the lack of observations in the region and as reflected in the warm bias in model SST...

Hydrographic and current velocity observations collected from March 2001 to February 2003 on the west Antarctic Peninsula shelf as part of the Southern Ocean Global Ecosystems Dynamics program are used to characterize intrusions of Upper Circumpolar DeepWater (UCDW) and Lower Circumpolar DeepWater (LCDW) onto the shelf and Marguerite Bay. UCDW is f...

The Ocean Reference Station at 20°S, 85°W under the stratus clouds west of northern Chile is being maintained to provide ongoing climate-quality records of surface meteorology; air-sea fluxes of heat, freshwater, and momentum; and of upper ocean temperature, salinity, and velocity variability. The Stratus Ocean Reference Station (ORS Stratus) is su...

The Woods Hole Oceanographic Institution (WHOI) Hawaii Ocean Timeseries (HOT) Site (WHOTS), 100 km north of Oahu, Hawaii, is intended to provide long-term, high-quality air-sea fluxes as a part of the NOAA Climate Observation Program. The WHOTS mooring also serves as a coordinated part of the HOT program, contributing to the goals of observing heat...

Observations of current velocity, temperature, salinity and pressure from a 2-year moored array deployment and four hydrographic cruises conducted by the United States Southern Ocean GLOBEC program on the western Antarctic Peninsula continental shelf are used to characterize the ocean circulation and its connection to fresh water and heat fluxes on...

Southern Ocean GLOBal ocean ECosystems As part of the U.S. Southern Ocean GLOBEC program, moored time series measurements of temperature, conductivity (salinity), pressure, velocity, and acoustic backscatter were made from March 2001 to March 2003 in and near Marguerite Bay, located on the Antarctic Peninsula western shelf. To monitor surface forci...

A surface mooring was deployed in the eastern tropical Pacific west of northern Chile from the R/V Melville as part of the Eastern Pacific Investigation of Climate (EPIC). EPIC is a CLIVAR study with the goal of investigating links between sea surface temperature variability in the eastern tropical Pacific and climate over the American continents....

The contribution of the winds and the topography in the induction of upwelling along the Chilean coastal zone is calculated. The topographic-induced upwelling is estimated taking into account the effect of the meridional changes of the coastline orientation. The wind-induced upwelling was calculated for the austral summer using NSCAT scatterometer...