What Processes Drive Southern Ocean Sea Ice Variability and Trends? Insights from the Energy Budget of the Coupled Cryosphere-ocean-atmosphere System

GSTDTAP

项目编号	1643436
	What Processes Drive Southern Ocean Sea Ice Variability and Trends? Insights from the Energy Budget of the Coupled Cryosphere-ocean-atmosphere System
	Aaron Donohoe
主持机构	University of Washington
项目开始年	2017
	2017-05-01
项目结束日期	2020-04-30
资助机构	US-NSF
项目类别	Standard Grant
项目经费	387742(USD)
国家	美国
语种	英语
英文摘要	This project will use observations and coupled climate model simulations to examine the causes of sea ice variability. Sea ice in the Southern Ocean has increased in area over the observational record but researchers have yet to agree on the cause. Researchers suggests that changes in surface winds, upper-ocean freshening, or internal ocean/atmosphere variability could be the main driver for the increase in sea ice area. This project will determine how much of the change in sea ice area from year to year is due to oceanic, atmospheric, and radiative processes. Reconciling the observation-based understanding with model representations of sea ice variability will improve confidence in projections of future changes in Southern Ocean sea ice. The goal of this proposal is to improve our understanding of the processes that drive Southern Ocean sea ice year-to-year variability and long term trends. This knowledge will provide insight into how Southern Ocean sea ice responded to greenhouse gas and ozone forcing in the past and how it will respond in the future. The energy budget of the coupled cryosphere/ocean/atmosphere climate system will be used as a framework to disentangle drivers and responses during sea ice loss events. The technique consists of: (i) calculating the coupled energy budget of the climate system at the monthly timescale, (ii) isolating the radiative impact of sea ice variability from the radiative impact of cloud variability in the observed satellite radiation record and (iii) analyzing the vertical structure of atmospheric energy transport to determine the vertical profile of energy transport into the atmospheric column. This framework will allow the investigators to distinguish whether ice loss events are triggered by oceanic processes, atmospheric dynamics, or radiative processes. Preliminary results show that a diversity of mechanisms can drive Southern Ocean sea ice variability in coupled climate models whereas observed sea ice variability appears to be dominated by atmospheric dynamics. The exploration of biases between models and observations in both the mean state and in specific processes will yield more accurate projections of the future of sea ice in the Southern Ocean.
来源学科分类	Geosciences - Polar Programs
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/71029
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Aaron Donohoe.What Processes Drive Southern Ocean Sea Ice Variability and Trends? Insights from the Energy Budget of the Coupled Cryosphere-ocean-atmosphere System.2017.