Arctic Sea Ice Causes Seasonal Differences in the Response of Arctic Water Vapor to Climate Warming in the CMIP6 Model, HadGEM3-GC3.1

Water vapor in the Arctic can be attributed to local evaporation and transport from mid-latitudes. Here we investigate the response of Arctic water vapor to declining sea ice in a climate model, using an idealized warming scenario in which the Arctic becomes ice free year-round. We find distinct monthly patterns in water vapor change with warming, with a strong influence of sea ice loss on changes to evaporation, except in summer when transports dominate. Before the Arctic becomes ice-free, total column water increases at a rate slower than that indicated by the Clausius-Clapeyron relationship; once ice-free, total column water increases at a rate equal to Clausius-Clapeyron. The exception is summer when the increase is initially faster then becomes slower when ice-free. The boundary layer structure changes, under global warming, from stratified to well mixed in all seasons except summer, which remains largely unchanged throughout the ice-free transition.

Automated summary

The study investigates the impact of declining sea ice on Arctic water vapor using a climate model. It shows that the changes in water vapor are influenced by both local evaporation and transport from mid-latitudes. The study also reveals distinct patterns in water vapor change, with sea ice loss affecting evaporation except in summer when transports dominate.