Is Greenland’s Ice Disappearing?
Image Source: AVweb, August 2018
I. Emergency Landing In 1942
In July, 1942, a squadron of six U.S. P-38 fighter planes and two B-17 bombers embarked on a flight mission to England when they were suddenly bombarded by severe weather.
All 8 planes were consequently forced to emergency-land on the southeastern corner of the Greenland ice sheet, about 29 kilometers from the coastal edge.
While all 25 of the occupants were ultimately rescued, the 8 planes had to be abandoned atop the surface of Greenland as it existed in 1942. Eventually the planes were buried beneath decades of ice and snow accumulation.
II. The first “Lost Squadron” plane rescued in 1992…buried under 268 feet of ice
Over the course of the next several decades, nostalgic interest in a search-and-recovery effort grew. After all, the Lost Squadron planes were effectively new when they were abandoned and, if preserved well enough, they could potentially be restored to flying condition .
The first several attempts to locate the planes during the 1980s were unsuccessful, as the search crews had underestimated how deep beneath the surface the planes were after 40-plus years of ice sheet growth. It ultimately took 12 tries before the first plane was spotted.
In 1988 the search crews were finally able to pinpoint the location of a P-38 that was ultimately named “Glacier Girl”. She was buried 260 feet (79.2 meters) below the surface of the ice sheet as it existed in 1988.
By 1992 the 260-foot depth had grown to 268 feet (81.7 meters), and “Glacier Girl” was slowly (piece-by-piece) retrieved from the ice.
III. Another Lost Squadron plane was found in mid-2018…buried under 340 feet of ice
Accompanied by far less fanfare, another Lost Squadron P-38 was located in 2018 using drone technology.
This plane was found buried under another 72 feet – 21.9 meters – of ice relative to the 1992 recovery site for the first P-38 rescue (340 feet versus 268 feet).
IV. Potential implications and Greenland observations
• Greenland’s interior ice is melting more slowly now than 95% of the last 9,000 years
Image Source: MacGregor et al., 2016 and AAAS press release
• An anthropogenic influence on Greenland’s ice melt is too small to be detected
Image Source: Haine, 2016
• The Greenland Ice Sheet surface area is larger now than 95% of the last 8,000 years
Image Source: Briner et al., 2016
• Greenland hasn’t warmed overall since the 1920s and 1930s
Image Source: Hanna et al., 2011
“The annual whole [Greenland] ice sheet 1919–32 warming trend is 33% greater in magnitude than the 1994–2007 warming.” (Box et al., 2009)
• Greenland ice melt has added just 1.5 cm to sea levels since 1900 – with no contribution during 1940-2000
Image Source: Fettweis et al ., 2017
• Greenland has been cooling during the last decade
“Here we quantify trends in satellite-derived land surface temperatures and modelled air temperatures, validated against observations, across the entire ice-free Greenland. … Warming trends observed from 1986–2016 across the ice-free Greenland is mainly related to warming in the 1990’s. The most recent and detailed trends based on MODIS (2001–2015) shows contrasting trends across Greenland, and if any general trend it is mostly a cooling. The MODIS dataset provides a unique detailed picture of spatiotemporally distributed changes during the last 15 years. … Figure 3 shows that on an annual basis, less than 36% of the ice-free Greenland has experienced a significant trend and, if any, a cooling is observed during the last 15 years (<0.15 °C change per year).” (Westergaard-Nielsen et al., 2018)
“For the most recent 10 years (2005 to 2015), apart from the anomalously warm year of 2010, mean annual temperatures at the Summit exhibit a slightly decreasing trend in accordance with northern North Atlantic-wide cooling. The Summit temperatures are well correlated with southwest coastal records (Ilulissat, Kangerlussuaq, Nuuk, and Qaqortoq).” (Kobashi et al., 2017)
• Greenland was much warmer than today throughout most of the last 10,000 years
Image Source: Kobashi et al., 2017
“Greenland temperature reached the Holocene thermal maximum with the warmest decades occurring during the Holocene (2.9 °C warmer than the recent decades) at 7960 ± 30 years B.P.” (Kobashi et al., 2017)
Image Source: McFarlin et al., 2018
February 11, 2019 at 05:19AM