The Rossby radius in the Arctic Ocean

Abstract

Abstract. The first (and second) baroclinic deformation (or Rossby) radii are presented north of ∼ 60 • N, focusing on deep basins and shelf seas in the high Arctic Ocean, the Nordic seas, Baffin Bay, Hudson Bay and the Canadian Arctic Archipelago, derived from climatological ocean data. In the high Arctic Ocean, the first Rossby radius increases from ∼ 5 km in the Nansen Basin to ∼ 15 km in the central Canadian Basin. In the shelf seas and elsewhere, values are low (1-7 km), reflecting weak density stratification, shallow water, or both. Seasonality strongly impacts the Rossby radius only in shallow seas, where winter homogenization of the water column can reduce it to below 1 km. Greater detail is seen in the output from an ice-ocean general circulation model, of higher resolution than the climatology. To assess the impact of secular variability, 10 years (2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012) of hydrographic stations along 150 • W in the Beaufort Gyre are also analysed. The first-mode Rossby radius increases over this period by ∼ 20 %. Finally, we review the observed scales of Arctic Ocean eddies.

Satellite radar observations of small eddies in the White, Barents and Kara seas

“…Результа-ты расчета для июля -августа показали, что минимальное и максимальное значения радиуса для Белого моря составили 1,3 и 8 км, для Баренцева моря 0,2 и 9,5 км, для Карского моря 0,2 и 6 км. Его средние значения равны 4,3; 4,9 и 3 км для Белого, Баренцева и Карского морей соответственно, что не противоречит оценкам радиуса Россби, полученным для теплого времени го-да на основе другой базы данных [15]. Кроме того, согласно данным много-летних натурных измерений в отдельных районах Белого моря, сезонная и межгодовая изменчивость радиуса Россби также находилась в пределах 1 -8 км со средними значениями, близкими к климатическим оценкам [13].…”

Monitoring the mesoscale eddies of the Lofoten Basin: importance, progress, and challenges

“…In the Lofoten Basin at 70°N, the meridional resolution (2 × grid spacing) of the AVISO14 data is reduced to one-third of the zonal resolution. It is well established that a minimum of two grid-points per eddy radius is necessary to 'resolve' eddies adequately and one grid-point per eddy radius to 'permit' eddies (Nurser and Bacon 2014). The high zonal resolution of the AVISO14 data resolves the eddy, whereas the meridional resolution, although lower, is high enough to permit the eddy.…”

Prospects for improving the representation of coastal and shelf seas in global ocean models

“…For L T , values < 100 km are widely distributed across the ocean, reflecting features such as ridges and sills. Values < 10 km are, however, restricted to the slopes at the ocean margins between the deep ocean and ei- Nurser and Bacon (2014), using the model run described by Marzochhi et al (2015); (b) barotropic Rossby radius calculated from ORCA12 bathymetry; (c) topographic scale calculated from ORCA12 bathymetry and mesh; (d) tidal excursion, calculated from TPXO barotropic tidal currents (Egbert and Erofeeva, 2002). ther the continents or the continental shelves. For the baroclinic Rossby radius (L 1 ), values < 10 km occur in highlatitude oceans, whereas values < 6 km are limited to continental shelves.…”