Influence of Early Spring Arctic Sea Ice on Midsummer Precipitation in Northeast China: The Intermediate Links and Temporal-Spatial Channels

Abstract

Previous studies revealed that the Arctic sea ice in March can influence the July–August (JA) precipitation over northeast China (NEC). We are curious about what happens in the atmosphere during the intermediate months of April, May, and June. In this study, we use atmospheric heat source as an intermediate quantity to link the sea ice and precipitation, and aim to find the intermediate stations where atmospheric heat source can well link to both March Arctic sea ice and the JA precipitation in NEC. The stations can appear in different locations and different intermediate months. Lagged correlations are calculated to infer the response of the heat source to sea ice and the response of precipitation to the heat source. Results show that there exist two spatial-temporal channels. The first is a direct path over high latitudes, with intermediate station appearing in April at a location between Arctic and NEC. The second is a circuitous path, with intermediate station appearing in June over the equatorial Indian Ocean, which can excite a wave train that finally affects the JA precipitation in NEC. The influence of March Arctic sea ice on the JA precipitation in NEC can be contributed jointly by these two temporal-spatial channels.