Enhanced Arctic sea ice melting controlled by larger heat discharge of mid-Holocene rivers
Jiang Dong, Xuefa Shi, Xun Gong, А. С. Астахов, Limin Hu, Xiting Liu, Gang Yang, Yixuan Wang, Yuriy P. Vasilenko, Shuqing Qiao, Aleksandr A. Bosin, Gerrit Lohmann
Abstract
Arctic sea ice retreat is linked to extrapolar thermal energy import, while the potential impact of pan-Arctic river heat discharge on sea-ice loss has been unresolved. We reconstructed the Holocene history of Arctic sea ice and Russian pan-Arctic river heat discharge, combining ice-rafted debris records and sedimentation rates from the East Siberian Arctic Shelf with a compilation of published paleoclimate and observational data. In the mid-Holocene, the early summer (June-July) solar insolation was higher than that during the late Holocene, which led to a larger heat discharge of the Russian pan-Arctic rivers and contributed to more Arctic sea ice retreat. This intensified decline of early-summer sea ice accelerated the melting of sea ice throughout the summertime by lowering regional albedos. Our findings highlight the important impact of the larger heat discharge of pan-Arctic rivers, which can reinforce Arctic sea-ice loss in the summer in the context of global warming.