Biddle, L.C., Swart, S. (2020). The observed seasonal cycle of submesoscale processes in the Antarctic marginal ice zone. Journal of Geophysical Research: Oceans, 125 (6), doi:10.1029/2019JC015587.
We utilized the open access MEOP database of temperature and salinity data from seal tags in the Southern Ocean to investigate the presence, variability and magnitude of submesoscale fluxes under and near the sea ice in the Weddell Sea. We show that horizontal buoyancy gradients strengthen in mid-winter, likely associated with variability in sea ice cover.
Swart, S., M. D. du Plessis, A. F. Thompson, L. C. Biddle, I. Giddy, T. Linders et al. (2020). Submesoscale fronts in the Antarctic marginal ice zone and their response to wind forcing. Geophysical Research Letters, 47, doi:10.1029/2019GL086649.
Autonomous robotic instruments, a Seaglider (profiling glider) and a Sailbuoy (surface glider) are used in combination to understand the interplay between surface winds and surface lateral density gradients. When winds are weaker, stronger gradients are able to develop, but rapidly disseminate with increased wind speed.
Biddle, L. C., B. Loose, and K. J. Heywood (2019). Upper ocean distribution of glacial meltwater in the Amundsen Sea, Antarctica. Journal of Geophysical Research: Oceans, doi: 10.1029/2019JC015133.
Using a combination of oxygen isotope ratios, noble gas concentrations and other hydrographic measurements, we highlight remaining issues with existing glacial meltwater identification techniques and improve on these. This reveals the upper ocean distribution of glacial meltwater in the Amundsen Sea – even up to 500 km from the ice shelf itself!
Biddle, L. C., K. J. Heywood, J. Kaiser, and A. Jenkins (2017). Glacial meltwater identification in the Amundsen Sea. Journal of Physical Oceanography, doi: 10.1175/JPO-D-16-0221.1.
This paper explores how we currently identify glacial meltwater and what other shelf processes may be affecting the calculations, including variations in CDW and WW endpoints and biological activity. It also introduces the 1D ocean model that I modified, mPWP, which includes sea ice and some basic parameterization of biological effects on dissolved oxygen.
Heywood, K. J., L. C. Biddle, L. Boehme, P. Dutrieux, M. Fedak, R. W. Jones, H. Mallett, I. A. Renfrew, and B. G. M. Webber (2017). Between the devil and the deep blue sea: the role of the Amundsen Sea continental shelf in exchanges between ocean and ice shelves. Oceanography, 29 (4). pp. 118-129. ISSN 1042-8275
A summary of measurements taken during the Ocean2ice campaign as part of the iSTAR project. We present a remarkable dataset from tagged seals that show the presence of an eddy on shelf, and examine how CDW is cooled as it travels across shelf through double diffusive mixing with the overlying WW layer.
Naveira Garabato, A. C., A. Forryan, P. Dutrieux, L. Brannigan, L. C. Biddle, K. J. Heywood, A. Jenkins, Y. L. Firing and S. Kimura (2017). Vigorous lateral export of the meltwater outflow from beneath an Antarctic ice shelf. Nature 542, 219–222, doi:10.1038/nature20825
Using turbulence measurements taken close to the outflow of Pine Island Ice Shelf in the Amundsen Sea, the dominant instabilities experienced by glacial meltwater as it exits the ice shelf are identified. These instabilities and resulting vigorous mixing result in the glacial meltwater settling at a depth of approximately 400 m as it flows away from the ice shelf.
Biddle, L. C., J. Kaiser, K. J. Heywood, A. F. Thompson, and A. Jenkins (2015). Ocean glider observations of iceberg‐enhanced biological production in the northwestern Weddell Sea. Geophys. Res. Lett., 42, doi:10.1002/2014GL062850.
Using high resolution Seaglider data, we observed peaks in dissolved oxygen concentrations and colored dissolved organic matter, associated with fresher and colder surface waters. This was linked to the recent passage of an iceberg through the area, and was remarkable for the small scales (<2 km) that they occurred over, therefore slipping through most remote sensing chlorophyll products.