Sea ice

Sea ice is in constant motion. Fast ice located along coastal boundaries is made relatively stable by anchoring to the shoreline and to the sea bottom 

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While this chapter is mainly concerned with the chemical interactions between ocean and atmosphere, a few words need to be said about the physical interactions, because of their general importance for climate. The main physical interaction between the ocean and atmosphere occurs through the exchange of heat, water and momentum, although the presence of sea-ice acts to reduce all of these exchanges to a greater or lesser extent. 

Winter temperatures in the arctic range between -50°C and -4°C. Expressed as a fraction of the melting point of sea ice, these correspond to the range 0.82 to 0.99 T. ... 

J. S. Wettlaufer, M. G. Worster, H. E. Huppert. Natural convection during solidification of an alloy from above with application to the evolution of sea ice. J Fluid Mech 344 291, 1997. 

Besides readings of Earth s surface temperatures taken with standard glass thermometers, direct readings of atmospheric temperatures have been taken with satellites and weather balloons. In addition to direct measurements of Earth s recent temperatures, proxy measurements of temperatures from farther in the past can be derived from borehole temperature measurements, from historical and physical evidence regarding the e xtent and mass of land and sea ice, and from the bleaching of coral reefs. 

Antarctica, they were thwarted by unusually heavy sea ice, which covered almost all of the harbor during the entire period of our... 

In another experiment, seawater was pumped from a sea-ice hole, incubated for 24 and 48 hours, and analyzed for pigment content. 

Such OGCM modeling also suggests the importance of ice-cover in controlling the amount of Thxs advection (Henderson et al. 1999a). Low particle fluxes beneath sea-ice may lead to low scavenging rates in these areas, particularly where ice cover is permanent. In these areas, °Thxs may be advected to the edge of the ice sheet where it is... 

The model includes a dynamic thermodynamic sea ice model. The dynamics of sea ice are formulated using viscous-plastic rheology [Hibler (1979)]. The thermodynamics relate changes in sea ice thickness to a balance of radiant, turbulent, and oceanic heat fluxes. The effect of snow accumulation on sea ice is included, along... 

Sea ice is represented in the model as a two-dimensional surface covered with a snowpack. Ice advection, rheology and snow cover are calculated from the sea-ice model embedded in MPIOM [Hibler (1979)]. The only source of pollutants for the ice compartment is deposition from the atmosphere. Once pollutants enter the ice compartment they can diffuse into the snow pore space air, dissolve in the interstitial liquid water or adsorb to the ice surface. Together with the sea ice the pollutants undergo advection. Sinks considered for the ice compartment are volatilisation to the atmosphere and release into the ocean with melt water. 

The previous model setup included an identical horizontal resolution for ocean and atmosphere, and online coupling was implemented in the ECHAM submodel with an exchange rate of 3 hours. In the current model setup atmosphere and ocean are coupled online using the Ocean-Atmosphere-Sea Ice-Soil (OASIS) coupler [Valcke et al (2004)] with a coupling time step of one day. OASIS passes boundary condi-... 

Processes not resolved in MPI-MCTM that also might serve as explanations for discrepancies between model results and observations are degradation of DDT in the ocean and degradation of DDT in the particle-bound state in air. Furthermore, the neglection of sea-ice had been shown to increase the northern hemisphere meridional DDT gradient [Guglielmo (2008)]. 

Program DAV10 is an 18 reservoir energy balance climate using the long wave radiation formulation of Kuhn et al. (1989) in LWFLUX Albedo formulation of Thompson and Barron in SWALSEDO with land and sea ice. 

As an alternative numerical experiment, I suppress all ice formation by modifying subroutine SWALBEDO. The modifications are to set the fraction of the ocean covered by sea ice to zero, regardless of temperature, and to set an unattainably low temperature limit in the IF statement that branches to temperature-dependent albedo on land. The program is listed as DAV11. 

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