|
|
同学们，法国里尔一大，招一个流体力学的博士，提供奖学金，随时来随时开始，看看你们周围谁有这个意向可以告诉他们下，招收条件在PDF，有需要的话可以联系QQ：920707048
Context and objective:
The extent of sea ice during summer in the Arctic Ocean is among the most sensitive
indicators of the ongoing climate change. During the last summers satellites have recorded
an exceptional reduction of the Arctic sea-ice pack to an extent that none of the available
large-scale numerical Global Climate models could predict. The observed ice loss has lead
scietists to question their quantitative understanding of the dynamical and
thermodynamical processes involved in the summer season melting and with it to
reconsider several of the simplifying assumptions on which the current large-scale
computer models are based.Features related to water ponds forming over melted ice are too
small to be directly accounted for in large-scale models. Melt ponds and their surface
topography are an important contributor to the surface albedo of the Arctic Ocean, which is
a key factor for the global climate. Presently, the main challenge in sea ice climate science is
to physically improve the models in order to refine their predictive power.
!
This research project addresses the problem of the growth process of ice melt ponds in the
Arctic during the summer season by focusing on the small-scale mechanisms controlling
the evolution of the basin topography of a single melt pond. In particular we study the
phenomenology of the thermal convective flow in the pond, which is known to be highly
turbulent, and its interaction with the phase-change mechanisms at the pond boundaries.
The goal of the present project is to reach a sound understanding on how fluid dynamics
and phase-change processes contribute in determing the pond growth in order to provide
useful guidelines for parametrizations in large-scale models. The proposed research is
based on numerical simulations. A computational-fluid dynamics code is to be developed
(using the Lattice-Boltzmann Method), in order to describe both the turbulent convective
dynamics of melted water, with its inherent salt content, and the ice phase change under
realistic conditions. We shall then extend the small-scale simulation results to the medium
and large scales. Our objective is to derive simplified parameterizations suitable for the
implementation in large-scale ice-ocean models used for Earth System modelling.
LML_Subject_Thesis_Form.pdf
(67.74 KB, 下载次数: 1)
|
|
/1 
窥视卡
雷达卡
发表于 2014-11-10 10:31:23
收藏
提升卡
变色卡
千斤顶
显身卡
发表于 2014-11-10 11:13:05
