CPOM Staff based at UCL
Fern Scott
| email: fs |
tel: 0207.679.4406 |
| fax: 0207.679.7883 |
Fern was awarded a M.Sc in Mathematics from the UCL in 2004 and obtained a B.Sc in Mathematics, also from UCL, in 2003.
Her research project is entitled "Modelling melt ponds on sea ice".
Project
Background:
Seawater
freezes to form sea ice at the surface of the polar oceans. Sea ice covers
about 10% of the Earth's surface at its maximum extent and is predominantly
a thin veneer with a thickness ranging from a few tens of centimetres to several
metres. During the summer melt season, melt pools of relatively pure water
form upon the surface of sea ice due to the absorption of incident short-wave
(solar) radiation. These melt pools have a spectrally-averaged albedo which
is lower than that of the bare sea-ice surface and thus preferentially absorb
solar radiation which increases their horizontal and vertical extent. The
growth and spread of melt pools is important because it affects the energy
budget in the polar regions. It does this through the change in sea ice albedo,
and the modified sensible heat flux from the ocean through the thinner sea
ice layer. Also, when melt pool formation leads to partial melting of the
sea ice layer, latent heat is trapped in the water which retards subsequent
freezing during winter. The processes involved in the
evolution of melt pools and their implications for the energy budget have
received little detailed theoretical attention.
The project will investigate the areal evolution of melt ponds on the surface of Arctic sea ice, through numerical modelling, theoretical study and consideration of field work and satellite imagery. Initially, a cellular automaton model will be constructed to simulate the spreading of melt ponds across a sea ice floe. The rules for cell advancement will be the subject of detailed process studies involving flow through a porous media, and melt/freeze rates determined using a radiative-thermodynamic model of sea ice treated as a mushy layer of the sodium chloride-water alloy. This model will be used to investigate the different melt pond coverage characteristics of first year and multiyear sea ice, and a relation will be sought between the areal pond evolution and the thickness distribution function used in climate models. It is hoped that a modified summer albedo parameterization can be developed for use in a sea ice climate model.