Prof Langhorne, who is already in the Antarctic undertaking research, has been allocated the funding by the Deep South National Science Challenge.
This is one of 11 Ministry of Business, Innovation and Employment-funded challenges aimed at taking a more strategic approach to science investment.
Prof Langhorne's project, ''Targeted observation and process-informed modelling of Antarctic sea ice'', is among the first Deep South funding allocations that will result in $9million being spent on six projects over four years.
The presence of Antarctic sea ice maintains cold conditions that help sustain the Antarctic's ice sheets, she points out.
The sea ice also affects the rate of global warming by influencing ocean heat uptake in the Southern Ocean.
Antarctic sea ice had a significant influence on ''both the ocean and atmospheric components'' of the climate system, and variability in sea ice extent was ''coupled with the occurrence of weather systems over New Zealand'', she said.
Satellite observations showed the maximum total extent of sea ice around the Antarctic had been increasing slowly over the past three decades, a behaviour ''superficially at odds'' with the concept of global warming.
Earth System Models, a kind of global climate model that seeks to simulate key physical, chemical and biological processes, could not ''faithfully reproduce these recent trends in sea ice coverage'', particularly their varying regional response, she said.
Through preparation and modelling work in New Zealand, and field experiments on the ground in the Antarctic, Prof Langhorne's project aims to focus on the inner and outer margins of the Antarctic sea ice cover where it had been observed to grow and recede fastest.
The study would increase understanding of ''drivers of growth and decay'' in sea ice and connect with other complementary research activities.
These discoveries would be incorporated into the sea ice module, to be used by the first New Zealand Earth System Model, which was being developed by Niwa.
This Niwa project has also gained a $1.9million allocation in Deep South challenge funding. The project's principal researcher is Dr Olaf Morgenstern.
Other funded Deep South projects: Victoria University of Wellington, Dave Frame, $1.4million; Canterbury University, Adrian McDonald, $1.8million; Bodeker Scientific, Greg Bodeker, $1.1million; Auckland University, Dr Melissa Bowen, $1illion.
