Antarctic

Number of papers: 15

Unprecedented mass gain over the Antarctic ice sheet between 2021 and 2022 caused by large precipitation anomalies — Environmental Research Letters, 2023; Wang et al.

“The results show that the continuous mass loss in the AIS between 2003 and 2020 was 141.8 ± 55.6 Gt yr−1 . However, the AIS showed a record-breaking mass gain of 129.7 ± 69.6 Gt yr −1 between 2021 and 2022. During this period, the mass gain over the East AIS and Antarctic Peninsula was unprecedented within the past two decades, and it outpaced the mass loss in the Amundsen sector of the West AIS from 2003 to 2022.”

How increasing CO2 leads to an increased negative greenhouse effect in Antarctica — Geophysical Research Letters, 2015; Schmithüsen et al.

On the high plateau of Antarctica, the land is as high as the lapse rate elsewhere, leading to accelerated radiation to space. The authors discuss the effect of adding CO2 in this environment — it cools the surface rather than warms it.

Change in Antarctic ice shelf area from 2009 to 2019 — European Geophysical Union, 2023; Andreasen et al.

“Overall, the Antarctic ice shelf area has grown by 5305 km2 since 2009, with 18 ice shelves retreating and 16 larger shelves growing in area. Our observations show that Antarctic ice shelves gained 661 Gt of ice mass over the past decade, whereas the steady-state approach would estimate substantial ice loss over the same period, demonstrating the importance of using time-variable calving flux observations to measure change.”

Significant West Antarctic Cooling in the Past Two Decades Driven by Tropical Pacific Forcing — Bulletin of the American Meteorological Association, 2023; Zhang et al.

“During the second half of the twentieth century, the West Antarctic Ice Sheet (WAIS) has undergone significant warming at more than twice the global mean and thus is regarded as one of the most rapidly warming regions on Earth. However, a reversal of this trend was observed in the 1990s, resulting in regional cooling. In particular, during 1999–2018, the observed annual average surface air temperature had decreased at a statistically significant rate, with the strongest cooling in austral spring.”

Mass balance of the Antarctic ice sheet 1992–2016: Reconciling Results from GRACE Gravimetry with ICESat, ERS1/2 and Envisat Altimetry — Journal of Glaciology, 2021; Zwally et al.

“Beginning in 2009, large increases in coastal WA dynamic losses overcame long-term EA and inland WA gains bringing Antarctica close to balance at −12 ± 64 Gt a−1 by 2012–16.” — This is a trivial percentage of the ice mass and could well net out to zero, far less than others have estimated.

Delayed Antarctic sea-ice decline in high-resolution climate change simulations — Nature Communications, 2022; Rackow et al.

These authors assume CO2 causes climate change, whatever that is, but their ice data shows that it hasn’t come to Antarctica yet: “Here we present multi-resolution climate change projections that account for Southern Ocean mesoscale eddies. The high-resolution configuration simulates stable September Antarctic sea-ice extent that is not projected to decline until the mid-21st century.”

Change in Antarctic ice shelf area from 2009 to 2019 — Cryosphere, 2023; Andreasen et al.

“Over the last decade, a reduction in the area on the Antarctic Peninsula (6693 km2) and West Antarctica (5563 km2) has been outweighed by area growth in East Antarctica (3532 km2) and the large Ross and Ronne–Filchner ice shelves (14 028 km2). The largest retreat was observed on the Larsen C Ice Shelf, where 5917 km2 of ice was lost during an individual calving event in 2017, and the largest area increase was observed on Ronne Ice Shelf in East Antarctica, where a gradual advance over the past decade (535 km2 yr−1) led to a 5889 km2 area gain from 2009 to 2019. Overall, the Antarctic ice shelf area has grown by 5305 km2 since 2009, with 18 ice shelves retreating and 16 larger shelves growing in area. Our observations show that Antarctic ice shelves gained 661 Gt of ice mass over the past decade …”

Antarctica ice sheet basal melting enhanced by high mantle heat — Earth-Science Reviews, 2022; Irina Artemieva

“Antarctica is losing ice mass by basal melting associated with processes in deep Earth and reflected in geothermal heat flux.”

Geothermal heat flow and thermal structure of the Antarctic lithosphere —Geophysical Research Letters, 2022; Haeger et al.

Summary: An important challenge of our time is to predict the behavior of large ice sheets like the Antarctic Ice Sheet and its potential contribution to rising sea level. Of the many factors influencing the ice, the heat emitted by the Earth is one of the least understood. Existing models of the so-called geothermal heat flow show substantial differences both in strength and distribution. We combine data on the Earth’s gravity field and earthquake-based tomography to generate a new model of geothermal heat flow, which agrees well with the location of volcanos. Our results can represent another piece in the puzzle to explain observations that report accelerating loss of ice masses.

Impact of Winds and Southern Ocean SSTs on Antarctic Sea Ice Trends and Variability — Journal of Climate, 2021; Blanchard-Wrigglesworth et al.

“Antarctic sea ice extent (SIE) has slightly increased over the satellite observational period (1979 to the present) despite global warming. Several mechanisms have been invoked to explain this trend, such as changes in winds, precipitation, or ocean stratification, yet there is no widespread consensus. Additionally, fully coupled Earth system models run under historic and anthropogenic forcing generally fail to simulate positive SIE trends over this time period.”

Positive Trend in the Antarctic Sea Ice Cover and Associated Changes in Surface Temperature — Journal of Climate, 2017; Comiso et al.

“The Antarctic sea ice extent has been slowly increasing contrary to expected trends due to global warming and results from coupled climate models. After a record high extent in 2012 the extent was even higher in 2014 when the magnitude exceeded 20 × 106 km2 for the first time during the satellite era. … The results suggest that the positive trend is a consequence of the spatial variability of global trends in surface temperature and that the ability of current climate models to forecast sea ice trend can be improved through better performance in reproducing observed surface temperatures in the Antarctic region.”

Mass balance of the Antarctic ice sheet 1992–2016: reconciling results from GRACE gravimetry with ICESat, ERS1/2 and Envisat altimetry — The Global Cryosphere, 2021; Zwally et al.

They conclude: With Antarctic Peninsula loss of −26 Gt a−1, the Antarctic total gain is 95 ± 25 Gt a−1 during 2003–08, compared to 144 ± 61 Gt a−1 from ERS1/2 during 1992–2001. Beginning in 2009, large increases in coastal WA dynamic losses overcame long-term EA and inland WA gains bringing Antarctica close to balance at −12 ± 64 Gt a−1 by 2012–16.

In plain english: no, Antarctica is not losing ice. The mass balance varies a bit, but on the whole it hasn’t changed in 30 years.

Antarctic ice-shelf advance driven by anomalous atmospheric and sea-ice circulation —Nature Geoscience (2022); Christie et al.

More inconvenient truths for Al Gore: “Abrupt recessions in ice-shelf frontal position presaged the break-up of Larsen A and B, yet, in the ~20 years since these events, documented knowledge of frontal change along the entire ~1,400-km-long eastern Antarctic Peninsula is limited. Here, we show that 85% of the seaward ice-shelf perimeter fringing this coastline underwent uninterrupted advance between the early 2000s and 2019, in contrast to the two previous decades. We attribute this advance to enhanced ocean-wave dampening, ice-shelf buttressing and the absence of sea-surface slope-induced gravitational ice-shelf flow. These phenomena were, in turn, enabled by increased near-shore sea ice driven by a Weddell Sea-wide intensification of cyclonic surface winds around 2002. Collectively, our observations demonstrate that sea-ice change can either safeguard from, or set in motion, the final rifting and calving of even large Antarctic ice shelves.”

Evidence of an active volcanic heat source beneath the Pine Island Glacier — Nature Communications, 2018; Loose et al.

This paper, which does not mention CO2 even once, says “Our finding of a substantial volcanic heat source beneath a major WAIS glacier highlights the need to understand subglacial volcanism, its hydrologic interaction with the marine margins, and its potential role in the future stability of the WAIS.”

Foehn Event Triggered by an Atmospheric River Underlies Record-Setting Temperature Along Continental Antarctica — JGR Atmospheres, 2018; Bozkurt et al.

“A record-setting temperature of 17.5°C occurred on 24 March 2015 at the Esperanza station located near the northern tip of the Antarctic Peninsula (AP). We studied the event using surface station data, satellite imagery, reanalysis data, and numerical simulations. The Moderate Resolution Imaging Spectroradiometer Antarctic Ice Shelf Image Archive provides clear evidence for disintegration and advection of sea ice, as well as the formation of melt ponds on the ice sheet surface at the base of the AP mountain range. A deep low-pressure center over the Amundsen-Bellingshausen Sea and a blocking ridge over the southeast Pacific provided favorable conditions for the development of an atmospheric river with a northwest-southeast orientation, directing warm and moist air toward the AP, and triggering a widespread foehn episode.”