Interannual Climate Variability in the West Antarctic Peninsula under Austral Summer Conditions

Eduardo Santamaría-Del-Ángel,Mary-Luz Cañon-Páez,Jesús-A Aguilar-Maldonado,Angelica-L Gutierrez,Maria-Teresa Sebastiá-Frasquet,Adriana González-Silvera,Jorge López-Calderón,Víctor Camacho-Ibar,Alejandra Castillo-Ramírez,Andrés Franco-Herrera

doi:10.3390/rs13061122

Abstract

This study aimed to describe the interannual climate variability in the West Antarctic Peninsula (WAP) under austral summer conditions. Time series of January sea-surface temperature (SST) at 1 km spatial resolution from satellite-based multi-sensor data from Moderate Resolution Imaging Spectrometer (MODIS) Terra, MODIS Aqua, and Visible Infrared Imager Radiometer Suite (VIIRS) were compiled between 2001 and 2020 at localities near the Gerlache Strait and the Carlini, Palmer, and Rothera research stations. The results revealed a well-marked spatial-temporal variability in SST at the WAP, with a one-year warm episode followed by a five-year cold episode. Warm waters (SST > 0 °C) reach the coast during warm episodes but remain far from the shore during cold episodes. This behavior of warm waters may be related to the regional variability of the Antarctic Circumpolar Current, particularly when the South Polar Front (carrying warm waters) reaches the WAP coast. The WAP can be divided into two zones representing two distinct ecoregions: the northern zone (including the Carlini and Gerlache stations) corresponds to the South Shetland Islands ecoregion, and the southern zone (including the Palmer and Rothera stations) corresponds to the Antarctic Peninsula ecoregion. The Gerlache Strait is likely situated on the border between the two ecoregions but under a greater influence of the northern zone. Our data showed that the Southern Annular Mode (SAM) is the primary driver of SST variability, while the El Niño Southern Oscillation (ENSO) plays a secondary role. However, further studies are needed to better understand regional climate variability in the WAP and its relation with SAM and ENSO; such studies should use an index that adequately describes the ENSO in these latitudes and addresses the limitations of the databases used for this purpose. Multi-sensor data are useful in describing the complex climate variability resulting from the combination of local and regional processes that elicit different responses across the WAP. It is also essential to continue improving SST approximations at high latitudes.

Highlights

The ozone hole over the Antarctic was first reported in the spring of 1985 [1]
The apparent absence of this pattern in the Palmer (Figure 5c) and Rothera (Figure 5d) sites may be a consequence of coastal morphology, as well as the interactions between fjords and the dynamics of marine ice, all of which may produce greater variations in sea-surface temperature (SST) in these two locations (Figure 2, Tables 1 and 3), relative to the Carlini and Gerlache sites
The results by Turner et al [54] support the idea of regular ingress of warm water to the West Antarctic Peninsula (WAP) coasts

Summary

Introduction

The ozone hole over the Antarctic was first reported in the spring of 1985 [1]. This anomaly was one of the earliest global signals of how human activities can change the planetary climate. The Antarctic has played a key role in helping us understand global climate variability [2,3,4] This issue has led some 30 countries to launch research programs on the continent, installing over 100 permanent facilities and 36 temporary field stations therein; the West Antarctic Peninsula (WAP) harbors 13 permanent and 24 temporary stations [5]. This region has become a human activity hotspot [6], given its accessibility with regular boats; vessels with icebreaker capabilities are necessary to gain access to other parts of the continent. The WAP has been considered, since the late

Objectives

Methods

Results

Discussion

Conclusion