The formation of sea ice in polar regions is possible because a salinity gradient or halocline keeps the water column stable despite intense cooling. Here, we demonstrate that unique property central to maintenance halocline, namely, thermal expansion coefficient (TEC) seawater increases by one order magnitude between and tropical regions. Using fully coupled climate model, it shown that, even with excess precipitations, would not form at all if near-freezing temperature TEC was well below...

Abstract. Snow accumulation is the main positive component of mass balance in Antarctica. In contrast to major efforts deployed estimate its overall value on a continental scale – assess contribution ice sheet sea level rise knowledge about process itself relatively poor, although many complex phenomena occur between snowfall and definitive settling snow particles snowpack. Here we exploit dataset near-daily surface elevation maps recorded over 3 years at Dome C using an automatic laser...

The Arctic, a central place to our global climate, is mainly covered by sea ice. motion of ice important as it exports freshwater from the Arctic North Atlantic. itself on large scale driven atmospheric and oceanic patterns. Yet, fluctuating velocities are superimposed this mean circulation. These represent turbulence well internal dynamics. One main property sea-ice velocity its high intermittency induced fracturing To understand dynamical properties velocities, we study kinematic energy...

Abstract The stratification is primarily controlled by temperature in subtropical regions (alpha ocean) and salinity subpolar (beta ocean). Between these two lies a transition zone, often characterized deep mixed layers winter responsible for the ventilation of intermediate or layers. While primary interest, no consensus on what controls its position exists yet. Among potential candidates, we find wind distribution, air–sea fluxes, nonlinear cabbeling effect. Using an ocean general...

Abstract. The Southern Ocean hosts a winter deep mixing band (DMB) near the Antarctic Circumpolar Current's (ACC) northern boundary, playing pivotal role in Subantarctic Mode Water formation. Here, we investigate what controls presence and geographical extent of DMB. Using observational data, construct seasonal climatologies surface buoyancy fluxes, Ekman transport, upper stratification. strength upper-ocean stratification is determined using columnar index, defined as input necessary to...

Abstract. The Southern Ocean hosts a winter deep mixing band (DMB) near the Antarctic Circumpolar Current's (ACC) northern boundary, playing pivotal role in Subantarctic Mode Water formation. Here, we investigate what controls presence and geographical extent of DMB. Using observational data, construct seasonal climatologies surface buoyancy fluxes, Ekman transport, upper stratification. strength ocean stratification is determined using columnar index, defined as input necessary to produce...

In this study, we examine the factors that influence upper ocean pycnocline (UOP) stratification in Southern Ocean. The UOP is a layer located just below mixed and its controls rates of exchange heat, carbon, nutrients between interior atmosphere. We classify regions based on relative roles temperature salinity stabilizing layer, resulting alpha (temperature-stabilized), beta (salinity-stabilized), or transition (temperature salinity-stabilized) zones. Our analysis uses observation profiles...

<p>The equation of state seawater determines how density varies with temperature and salinity. Although it has long been known that the is nonlinear, there seems to be an overall feeling in physical oceanography community associated effects might secondary importance. This can seen for example from fact most current theories large-scale circulation pre-assume a linear state. Yet we contend here these nonlinearities are responsible main transition mixed layer properties observed...

<p>The stratification is primarily controlled by the temperature in subtropical regions (alpha ocean), and salinity subpolar (beta ocean). Between these two lies a transition zone where intense frontal systems are usually found, either Southern Ocean or North Atlantic Pacific basins. Transition zones often characterized deep mixed layers winter responsible for ventilation of intermediate layers. Here we want to investigate what determines latitudinal position zone. It generally...