Antarctic Ice Sheet Records Surprising Mass Gain After Decade of Accelerated Loss todayheadline

A comprehensive new study reveals the Antarctic Ice Sheet (AIS) experienced unexpected mass gain between 2021-2023, temporarily reversing a two-decade trend of accelerating ice loss that had been contributing significantly to global sea level rise. This remarkable shift comes after analysis of 22 years of satellite gravimetry data showing pronounced mass loss acceleration in several critical East Antarctic glacier basins.

Researchers from Tongji University, led by Dr. Wei Wang and Professor Yunzhong Shen, have documented these dramatic fluctuations using data from the GRACE (Gravity Recovery and Climate Experiment) and GRACE-FO satellite missions. Their findings, published in Science China Earth Sciences, provide crucial insights into Antarctica’s changing contribution to global sea levels.

Three Distinct Periods of Antarctic Mass Change

The study identifies three distinct periods of Antarctic ice mass behavior over the past two decades:

• 2002-2010: Moderate ice loss at -73.79±56.27 gigatonnes per year, contributing 0.20±0.16 mm annually to global sea level rise
• 2011-2020: Nearly doubled ice loss rate of -142.06±56.12 gigatonnes per year, contributing 0.39±0.15 mm annually to global sea levels
• 2021-2023: Surprising reversal with mass gain of 107.79±74.90 gigatonnes per year, offsetting global sea level rise by 0.30±0.21 mm annually

This recent mass gain appears driven by anomalous precipitation accumulation across the continent. Despite this short-term reversal, the researchers emphasize that Antarctica’s contribution to global mean sea level rise peaked at 5.99±0.43 mm in February 2020, before declining slightly to 5.10±0.52 mm by the end of 2023.

East Antarctic Glaciers Show Concerning Instability

While previous research has often focused on rapid ice loss in West Antarctica, this study highlights concerning instability in four key glacier basins in East Antarctica’s Wilkes Land-Queen Mary Land (WL-QML) region: Totten, Moscow University, Denman, and Vincennes Bay.

These glacier systems showed alarming changes between the first two study periods, with mass loss intensifying by 47.64±8.14 gigatonnes per year during 2011-2020 compared to 2002-2010. What makes this finding particularly significant is that two of these glaciers – Vincennes Bay and Denman – transitioned from states of mass balance and accumulation to intense mass loss, respectively.

What’s Driving East Antarctic Ice Loss?

The researchers’ analysis reveals this accelerated mass loss stems from two primary factors: reduced surface mass balance (contributing 72.53% of the intensification) and increased ice discharge into the ocean (responsible for 27.47%).

“This accelerated mass loss was primarily driven by two factors: surface mass reduction (contributing 72.53%) and increased ice discharge (27.47%),” the researchers explained in their paper.

How should we interpret these findings in the context of long-term climate trends? While the recent mass gain provides a temporary reprieve from rising sea levels, the expanding inland mass loss areas in these East Antarctic glaciers present a concerning pattern that warrants continued monitoring.

Implications for Future Sea Level Rise

The potential destabilization of these East Antarctic glaciers carries profound implications. Complete disintegration of just these four glacier systems could potentially trigger more than 7 meters of global sea level rise, highlighting why their changing behavior demands scientific attention.

This study demonstrates how satellite gravimetry provides invaluable data for tracking Earth’s ice masses over extended periods. By examining both continent-wide patterns and regional changes, researchers can better understand the complex interplay between atmospheric conditions, ocean interactions, and ice sheet dynamics.

While the recent mass gain represents an interesting anomaly in Antarctic behavior, the long-term accelerating ice loss trend across multiple regions – including previously stable areas of East Antarctica – reminds us that continued monitoring of these critical ice masses remains essential for projecting future sea level rise and developing effective climate adaptation strategies.

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