Summertime cloud phase strongly influences surface melting on the Larsen C ice shelf, Antarctica

Ella Gilbert, Andrew Orr, John King, Ian Renfrew, Tom Lachlan Cope, Paul Field, Ian Boutle

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)
16 Downloads (Pure)

Abstract

Surface melting on Antarctic Peninsula ice shelves can influence ice shelf mass balance, and consequently sea level rise. We show that summertime cloud phase on the Larsen C ice shelf on the Antarctic Peninsula strongly influences the amount of radiation received at the surface and can determine whether or not melting occurs. While previous work has separately evaluated cloud phase and the surface energy balance (SEB) during summertime over Larsen C, no previous studies have examined this relationship quantitatively. Furthermore, regional climate models frequently produce surface radiation biases related to cloud ice and liquid water content. This study uses a high-resolution regional configuration of the UK Met Office Unified Model (MetUM) to assess the influence of cloud ice and liquid properties on the SEB, and consequently melting, over the Larsen C ice shelf. Results from a case-study show that simulations producing a vertical cloud phase structure more comparable to aircraft observations exhibit smaller surface radiative biases. A configuration of the MetUM adapted to improve the simulation of cloud phase reproduces the observed surface melt most closely. During a five-week simulation of summertime conditions, model melt biases are reduced to <2 W·m −2: a four-fold improvement on a previous study that used default MetUM settings. This demonstrates the importance of cloud phase in determining summertime melt rates on Larsen C.

Original languageEnglish
Pages (from-to)1575-1589
Number of pages15
JournalQuarterly Journal of the Royal Meteorological Society
Volume146
Issue number729
Early online date30 Jan 2020
DOIs
Publication statusPublished - Apr 2020

Keywords

  • Antarctic Peninsula
  • CLIMATE MODEL
  • ENERGY BALANCE
  • Larsen C ice shelf
  • MICROPHYSICS
  • MIXED-PHASE
  • PENINSULA
  • POLAR WEATHER RESEARCH
  • PRECIPITATION
  • RADIATION
  • SOUTHERN-OCEAN
  • SUPERCOOLED LIQUID WATER
  • cloud phase
  • regional climate modelling
  • surface energy balance
  • surface melt

Cite this