Daily updates return for Greenland Today, end for Antarctica Today

Daily melt extent mapping for Greenland Ice Sheet has resumed, while mapping for the Antarctic Ice Sheet has suspended for its winter season. Calibration of yearly melt detection requires analysis of the springtime snow conditions by a separate program. See our March 18, 2013 post for more discussion of melt calibration. A full analysis for the 2021-2022 melt season on the Antarctic Ice Sheet will be coming soon.

Daily image updates will resume for the Antarctic Ice sheet in October 2022.

Spring chillin’ in Greenland; Antarctica’s summer summary

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Seasonal surface melting in Greenland got off to a slow start in 2022. Persistent winds from the northwest across the melt-prone areas of the western coastal ice sheet have kept the total number of melt days well below average. Snowfall through last winter was slightly higher than average. In Antarctica, several areas had an intense coastal surface melting pulse at the end of the summer, in part associated with the extreme atmospheric river landfall event in mid-March.

Overview of conditions

Figure 1. Top left, cumulative melt days map of Greenland for the Spring 2022 melt season. Top right, map of the difference from the 1981-2010 average melt days for the same period. Bottom, daily melt area for Greenland from April 1st through June 20th, 2022, with daily melt area for the preceding five years. In gray are the mean daily melt area for 1981-2010, the inter-quartile range, and the interdecile range.

Figure 1. The top left map shows cumulative melt days on the Greenland Ice Sheet for the spring 2022 melt season. The top right map shows the difference from the 1981 to 2010 average melt days for the same period. The bottom graph shows daily melt area for Greenland from April 1 through June 20, 2022, with daily melt area for the preceding five years. The grey depicts the average daily melt area for 1981 to 2010, the inter-quartile range, and the interdecile range.

Credit: National Snow and Ice Data Center/T. Mote, University of Georgia
High-resolution image

Through June 20, 2022, the Greenland Ice Sheet had the lowest spring surface melt in the past decade. The total aerial extent of surface melting was just over 2.27 million square kilometers (876,000 million square miles), well below the 1981 to 2010 average of 3.72 million square kilometers (1.44 million square miles). Melting was below average along the western edge of the ice sheet (10 to 15 days behind the average rate) and near-average along the southeastern coast where melting occurred primarily at low elevations. A small area of the southern tip of the island had slightly above average melting.

Conditions in context

Figure 2. Top, average air temperature difference from the 1981-2010 average at the 700 mb level, or about 10,000 feet above sea level, for the period May 1st through June 20th; bottom, height difference from average for the 700mb pressure level in the atmosphere for the same period.||Credit: National Centers for Environmental Prediction (NCEP) Reanalysis data, National Center for Atmospheric Research).

Figure 2a. The top plot shows average air temperature as a difference from the 1981 2010 average at the 700 millibar level, or about 3,000 meters or 10,000 feet above sea level, from May 1 to June 20, 2022. The bottom plot shows height at the 700 millibars as a difference from average.

Credit: National Centers for Environmental Prediction (NCEP) Reanalysis data, National Center for Atmospheric Research).
High-resolution image

Figure 3. Surface mass balance for Greenland (SMB, the sum of snowfall and rainfall minus evaporation or runoff) relative to a 1981-2010 reference period for the autumn-winter-spring season for 2021-2022 (red line) through June 26th (based on forecast as well as re-analysis) and for several full-season comparison years in the record. The estimates come from a regional climate model forced by the ERA5 Reanalysis data and the GFS forecast based on daily weather measurements and projections. || Credit: MARv3.12, X. Fettweis, University of Liège, Belgium|High-resolution image

Figure 2b. This graph shows surface mass balance (SMB), which is the sum of all precipitation minus evaporation or runoff, for Greenland Ice Sheet relative to the 1981 to 2010 reference period. The red line depicts SMB from fall 2021 to spring 2022 through June 26 based on forecast and re-analysis. For comparison, several full-season years are shown. The estimates come from a regional climate model forced by the ERA5 Reanalysis data and the Global Forecast System (GFS) forecast based on daily weather measurements and projections.

Credit: MARv3.12, X. Fettweis, University of Liège, Belgium
High-resolution image

Air temperatures at the 700 millibar level (about 3,000 meters or 10,000 feet elevation) for May and June through June 20 were generally below average by about 1.5 degrees Celsius (3 degrees Fahrenheit) (Figure 2a). A small area of the southern tip of the island had slightly warmer-than average conditions. Near the National Science Foundation’s Summit Station, temperatures were about 2 degrees Celsius (4 degrees Fahrenheit) below average. The difference from average height of the 700 millibar pressure level is used to determine air pressure patterns over Greenland. The height indicates below average pressure off the southeastern coast extending to Iceland and relatively strong high pressure over Baffin Island and Labrador. This pattern drives winds from the northwest down across the western coast of Greenland, keeping conditions cooler than average there.

As noted above, total snowfall for the Greenland Ice Sheet in the 2021-2022 autumn-winter-spring period has been slightly greater than average by about 6 percent (Figure 2b). Areas of higher snowfall include the western coast and broad areas of the northern and eastern ice sheet, although in general the excess was small. A few areas at the southern tip and the southeastern coast had below average snow accumulation this season.

Greenland’s reflectivity

Figure 4. (a) Average Albedo, or net reflectivity, for the Greenland Ice Sheet for the 30 day period June 20th, 2022 relative to the same period for 2017-2022. Pink and reddish areas in the south and southwest indicate darker-than-average (relative to the preceding five years); dark blue band along the western coast indicate brighter than average snow conditions, due to below-average melt. ||Credit: Jason Box, Geological Survey of Denmark and Greenland (GEUS)|High-resolution image

Figure 3. This map shows the average reflectivity, also known as albedo, for the Greenland Ice Sheet, for the 30-day period up to June 20, 2022, relative to the same period for 2017 to 2022. Pink and reddish areas in the south and southwest indicate darker-than-average (relative to the preceding five years); dark blue band along the western coast indicates brighter than average snow conditions from below-average melt.

Credit: Jason Box, Geological Survey of Denmark and Greenland (GEUS)
High-resolution image

Greenland’s snow and ice reflectivity, known as albedo, can be tracked on a daily basis at a resolution of 300 meters (about 1,000 feet) using the European Space Agency’s Sentinel-3 satellite’s Ocean and Land Colour Instrument. This product is now available from the Geological Survey of Denmark and Greenland (GEUS). The map for June 20 shows a slightly darker surface over a broad region of the ice sheet, with narrow zones near the southern coast where some above average melting occurred. Most of the central western ice edge and southwest ice edge (ablation areas of the ice sheet) is considerably brighter than average because white snow covers the darker ice below late in to the spring season. This is usually the region with the darkest surface and greatest amount of bare ice in years with a strong early melt season.

Late summer melting in Antarctica

Figure 4a. The top map shows the total melt days for the Antarctic Ice Sheet from November 1, 2021, to April 30, 2022. The middle map shows Antarctica’s melt days as a difference from average relative to a 1990 to 2020 reference period. The bottom graph shows daily melt extent as a percent of the ice sheet for the 2021 to 2022 season through February 13, and the average values and ranges for the reference period. Credit: L. Lopez, NSIDC, M. MacFerrin, CIRES and T. Mote, University of Georgia|High-resolution image

Figure 4a. The upper left map shows the total melt days for the Antarctic Ice Sheet from November 1, 2021, to April 30, 2022. The upper right map shows Antarctica’s melt days as a difference from average relative to a 1990 to 2020 reference period. The bottom graph shows daily melt extent as a percent of the ice sheet for the 2021 to 2022 season through February 13, and the average values and ranges for the reference period.

Credit: L. Lopez, National Snow and Ice Data Center, M. MacFerrin, Cooperative Institute for Research in Environmental Sciences, and T. Mote, University of Georgia
High-resolution image

Figure 4b. These graphs show daily melt extent for two regions with late summer melt events. Both the Amundsen-Bellingshausen region and the Wilkes-Adelie Land region had significant melt events in March 2022. ||Credit: L. Lopez, NSIDC, M. MacFerrin, CIRES and T. Mote, University of Georgia|High-resolution image

Figure 4b. These graphs show daily melt extent for two regions with late summer melt events. Both the Amundsen-Bellingshausen region and the Wilkes-Adelie Land region had significant melt events in March 2022.

Credit: L. Lopez, National Snow and Ice Data Center, M. MacFerrin, Cooperative Institute for Research in Environmental Sciences, and T. Mote, University of Georgia
High-resolution image

Final maps and charts for the 2021 to 2022 melt season in Antarctica look very similar to the melt totals shown in our previous late February post, but two late-season melt events are noteworthy (Figure 4a). Around March 2 to 3, a strong melt event took place along the Amundsen Coast, including some of the Pine Island and Abbott Ice Shelf areas (Figure 4b). Then in mid-March, a powerful atmospheric river event pushed warm air and moisture onto the Wilkes Land coast and far up onto the East Antarctic Plateau, bringing extended melt conditions to the coast and astounding high temperature records to several high-elevation stations well inland. Both Dome Concordia, the European Antarctic Plateau research station, and Vostok Station, the Russian base at 3,500 meters (11,500 feet) elevation, shattered records for March high temperatures by ten or more degrees Celsius (over 18 degrees Fahrenheit). Overall, however, Antarctic melting remained near-average for the year, with only the Larsen Ice Shelf region and the Rio Baudoin Ice Shelf showing strong melting above the long-term average. Despite the late event, the Abbott Ice Shelf was one of the below-average melt areas, as was the Ross Embayment region with near-zero melting for the summer.

High snowfall in Antarctica for 2021 and 2022

Figure 7. Antarctica’s snowfall (surface mass balance) for the 2021-2022 hydrologic year and two recent years, differenced from the average trend (horizontal grey line) and the range for 90% of the years on record (grey band), from a climate model (MAR 3.12, based on ERA5 weather re-analysis data; ||Credit: X. Fettweis, University of Liège|High-resolution image

Figure 5. This graph shows Antarctica’s snowfall as a difference from average (horizontal grey line) for the 2021- 2022 hydrologic year and two recent years. The grey band indicates the range for 90 percent of the years on record from the MARv3.12 climate model based on ERA5 weather re-analysis data.

Credit: X. Fettweis, University of Liège, Belgium
High-resolution image

Above average snowfall for the past two years over the southern continent may equal or exceed the amount of ice loss from excess outflow from the glaciers and seasonal melting. Snowfall has been increasing over some coastal areas of Antarctica in recent years, but 2021 and 2022 had unusually high snow input. Increased airflow from the north to both Queen Maud Land and Wilkes Land increased warm moist air, resulting in high snowfall. The increased airflow over Wilkes Land also resulted in unusually warm conditions at the South Pole in recent decades (Clem et al., 2021). High snowfall has also been linked to the record low sea ice extent surrounding Antarctica because a lack of sea ice increases humidity.

References

Box, J. E., A. Wehrlé, D. van As, R. S. Fausto, K. K. Kjeldsen, A. Dachauer, A., et al. 2022Greenland ice sheet rainfall, heat and albedo feedback impacts from the mid-August 2021 atmospheric River. Geophysical Research Letters, e2021GL097356, https://doi.org/10.1029/2021GL097356

Clem, K. R., R. L. Fogt, J. Turner, B. R. Lintner, G. J. Marshall, J. R. Miller, and J. A. Renwick. 2020. Record warming at the South Pole during the past three decades. Nature Climate Change, 10(8), 762-770, https://doi.org/10.1038/s41558-020-0815-z

Mankoff, K. D., X. Fettweis, P. L Langen, M. Stendel, K. K. Kjeldsen, N. B. Karlsson, B. Noël, M. R. van den Broeke, A. Solgaard, W. Colgan, J. E. Box, S. B. Simonsen, M. D. King, A. P. Ahlstrøm, S. B.  Andersen, and R. S. Fausto. 2021. Greenland ice sheet mass balance from 1840 through next week. Earth System Science Data, 13, 5001–5025, https://doi.org/10.5194/essd-13-5001-2021