Observational and numerical assessment of meteorological characteristics and climate variabilities over the Antarctic Peninsula in recent decades

Abstract

Abstract The Antarctic Peninsula (AP) exhibits pronounced spatial variability in recent climate trends, with contrasting temperature changes between the West Antarctic Peninsula (WAP) and East Antarctic Peninsula (EAP). This study provides an observational and numerical assessment of meteorological characteristics and climate variability across the AP using automated weather station records, Reference Antarctic Data for Environmental Research (READER) data, the European Centre for Medium-Range Weather Forecasts (ERA5) reanalysis and high-resolution simulations from the Antarctic Mesoscale Prediction System (AMPS). The WAP and the entire AP show significant warming trends as a whole, while the EAP shows a persistent cooling trend over recent decade. The strongest warming is observed at Uranus Glacier in the WAP, whereas marked cooling occurs over the Larsen Ice Shelf in the EAP. AMPS and the ERA5 reanalysis highlight the influence of the orographic effect on the daily temperature variations between the regions. The EAP exhibits a consistent cooling pattern over the decades, with temperatures decreasing during 1985–2000 and 2010–2018. This cooling is driven by the easterly wind that crosses the Weddell Sea, which helps minimize disintegration or ice melt on the ice shelves. During intense El Niño periods, the EAP showed annual temperature decreases (−0.18°C ± 1.60°C) with correlation values of 0.796 and 0.837 with the El Niño index. The influence of the El Niño-Southern Oscillation on the EAP is less pronounced than on the WAP, where warming at Uranus Glacier and Limbert automatic weather station is linked to El Niño events and cooling periods are linked to La Niña events. The Interdecadal Pacific Oscillation also affects regional temperature variability, with an observed negative correlation ( r = −0.547, P < 0.05), which is the opposite pattern to that observed across much of the AP.