Influence of seasonal sea-ice loss on Arctic precipitation δ18O: a GCM-based analysis of monthly data

Abstract

Rapid Arctic warming and sea-ice loss have intensified the Arctic hydrological cycle, increasing local evaporation and precipitation. Stable water isotopes as environmental tracers can provide useful insights into the Arctic hydrological cycle. However, the paucity of isotopic observations in the Arctic has limited our understanding of the hydrological changes. Here, we use an isotope-enabled atmospheric general circulation model (IsoGSM) combined with the Global Network of Isotopes in Precipitation (GNIP) observations to investigate the relationship between sea-ice changes and Arctic precipitation δ18O (δ18Op) to reveal the relative influence of local air temperature and evaporation on Arctic summer and winter δ18Op. We find that the Arctic δ18Op is negatively correlated with sea-ice concentration but positively with air temperature. Sea-ice loss leads to enriched Arctic δ18Op through enhanced local evaporation and warming, but the relative importance of these processes varies between seasons. During summer, both local evaporation and warming contribute equally to δ18Op changes. In contrast, winter δ18O is predominantly driven by air temperature. This work improves our understanding of how Arctic precipitation isotopes respond to sea-ice changes and has implications for the Arctic hydrological cycle and palaeotemperature reconstructions.

Keywords

• precipitation isotope
• arctic warming
• sea ice
• local evaporation
• hydrological cycle
• palaeotemperature reconstruction