Two years of observations of warm-core anticyclones in the Labrador Sea and their seasonal cycle in heat and salt stratification
MetadataShow full item record
KeywordGeographic location/entity; North Atlantic Ocean; Circulation/ Dynamics; Mesoscale processes; Atm/Ocean Structure/ Phenomena; Anticyclones; Boundary currents; Observational techniques and algorithms; In situ oceanic observations; Variability; Seasonal cycle
Between 25 September 2007 and 28 September 2009, a heavily instrumented mooring was deployed in the Labrador Sea, offshore of the location where warm-core, anticyclonic Irminger rings are formed. The 2-year time series offers insight into the vertical and horizontal structure of newly formed Irminger rings and their heat and salt transport into the interior basin. In 2 years, 12 Irminger rings passed by the mooring. Of these, 11 had distinct properties, while 1 anticyclone likely passed the mooring twice. Eddy radii (11–35 km) were estimated using the dynamic height signal of the anticyclones (8–18 cm) together with the observed velocities. The anticyclones show a seasonal cycle in core properties when observed (1.9°C in temperature and 0.07 in salinity at middepth) that has not been described before. The temperature and salinity are highest in fall and lowest in spring. Cold, fresh caps, suggested to be an important source of freshwater, were seen in spring but were almost nonexistent in fall. The heat and freshwater contributions by the Irminger rings show a large spread (from 12 to 108 MJ m−2 and from −0.5 to −4.7 cm, respectively) for two reasons. First, the large range of radii leads to large differences in transported volume. Second, the seasonal cycle leads to changes in heat and salt content per unit volume. This implies that estimates of heat and freshwater transport by eddies should take the distribution of eddy properties into account in order to accurately assess their contribution to the restratification.
Author Posting. © American Meteorological Society, 2014. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 44 (2014): 427–444, doi:10.1175/JPO-D-13-070.1.
Showing items related by title, author, creator and subject.
Evaluating Southern Ocean biological production in two ocean biogeochemical models on daily to seasonal timescales using satellite chlorophyll and O2 / Ar observations Jonsson, Bror F.; Doney, Scott C.; Dunne, John P.; Bender, Michael L. (Copernicus Publications on behalf of the European Geosciences Union, 2015-02-04)We assess the ability of ocean biogeochemical models to represent seasonal structures in biomass and net community production (NCP) in the Southern Ocean. Two models are compared to observations on daily to seasonal ...
Observation of near-inertial wave reflections within the thermostad layer of an anticyclonic mesoscale eddy Byun, Sang-Shin; Park, Jong Jin; Chang, Kyung-Il; Schmitt, Raymond W. (American Geophysical Union, 2010-01-15)Moored current observations in the southwestern East/Japan Sea of 16.5 months duration clearly captured two episodes of downward phase propagation (upward energy propagation) of near-inertial waves (NIWs). Time series of ...
Laboratory experiments and observations of cyclonic and anticyclonic eddies impinging on an island Andres, Magdalena; Cenedese, Claudia (John Wiley & Sons, 2013-02-13)Laboratory experiments are conducted to investigate the interactions of self-propagating barotropic cyclones and baroclinic anticyclones with an island. Results are interpreted in the context of observations around Okinawa ...