GFS sfc_sice Module

This is three-layer thermodynomics sea-ice model based on Winton (2000) [195]. More...

Functions/Subroutines
subroutine	sfc_sice::sfc_sice_run (im, kice, sbc, hvap, tgice, cp, eps, epsm1, rvrdm1, grav, t0c, rd, ps, t1, q1, delt, sfcemis, dlwflx, sfcnsw, sfcdsw, srflag, cm, ch, prsl1, prslki, prsik1, prslk1, wind, flag_iter, use_lake_model, lprnt, ipr, thsfc_loc, hice, fice, tice, weasd, tsfc_wat, tprcp, tiice, ep, snwdph, qss_i, qss_w, snowmt, gflux, cmm, chh, evapi, evapw, hflxi, hflxw, islmsk, errmsg, errflg
subroutine	ice3lay
	This subroutine is the entity of three-layer sea ice vertical thermodynamics based on Winton(2000) [195] . More...

Detailed Description

General Algorithm

The model has four prognostic variables: the snow layer thickness \(h_s\), the ice layer thickness \(h_i\), the upper and lower ice layer temperatures located at the midpoints of the layers \(h_i/4\) and \(3h_i/4\) below the ice surface, respectively \(T_1\) and \(T_2\). The temperature of the bottom of the ice is fixed at \(T_f\), the freezing temperature of seawater. The temperature of the top of the ice or snow, \(T_s\), is determined from the surface energy balance. The model consists of a zero-heat-capacity snow layer overlying two equally thick sea ice layers (Figure 1). The upper ice layer has a variable heat capacity to represent brine pockets.

Fig.1 Schematic representation of the three-layer model

The ice model main program ice3lay() performs two functions:

• Calculation of ice temperature
  The surface temperature is determined from the diagnostic balance between the upward conduction of heat through snow and/or ice and upward flux of heat from the surface.
• Calculation of ice and snow changes
  In addition to calculating ice temperature changes, the ice model must also readjust the sizes of the snow and ice layers 1) to accommodate mass fluxes at the upper and lower surfaces, 2) to convert snow below the water line to ice, and 3) to equalize the thickness of the two ice layers.

Detailed Algorithm

Argument Table