Greenland Ice Sheet Surface Runoff Projections to 2200 Using Degree-Day Methods
Surface runoff from the Greenland ice sheet (GrIS) has dominated recent ice mass loss and is having significant impacts on sea-level rise under global warming. Here, we used two modified degree-day (DD) methods to estimate the runoff of the GrIS during 1950–2200 under the extensions of historical, R...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-11-01
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| Series: | Atmosphere |
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| Online Access: | https://www.mdpi.com/2073-4433/12/12/1569 |
| _version_ | 1797506668304531456 |
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| author | Chao Yue Liyun Zhao Michael Wolovick John C. Moore |
| author_facet | Chao Yue Liyun Zhao Michael Wolovick John C. Moore |
| author_sort | Chao Yue |
| collection | DOAJ |
| description | Surface runoff from the Greenland ice sheet (GrIS) has dominated recent ice mass loss and is having significant impacts on sea-level rise under global warming. Here, we used two modified degree-day (DD) methods to estimate the runoff of the GrIS during 1950–2200 under the extensions of historical, RCP 4.5, and RCP 8.5 scenarios. Near-surface air temperature and snowfall were obtained from five Earth System Models. We applied new degree-day factors to best match the results of the surface energy and mass balance model, SEMIC, over the whole GrIS in a 21st century simulation. The relative misfits between tuned DD methods and SEMIC during 2050–2089 were 3% (RCP4.5) and 12% (RCP8.5), much smaller than the 30% difference between untuned DD methods and SEMIC. Equilibrium line altitude evolution, runoff-elevation feedback, and ice mask evolution were considered in the future simulations to 2200. The ensemble mean cumulative runoff increasing over the GrIS was equivalent to sea-level rises of 6 ± 2 cm (RCP4.5) and 9 ± 3 cm (RCP8.5) by 2100 relative to the period 1950–2005, and 13 ± 4 cm (RCP4.5) and 40 ± 5 cm (RCP8.5) by 2200. Runoff-elevation feedback produced runoff increases of 5 ± 2% (RCP4.5) and 6 ± 2% (RCP8.5) by 2100, and 12 ± 4% (RCP4.5) and 15 ± 5% (RCP8.5) by 2200. Two sensitivity experiments showed that increases of 150% or 200%, relative to the annual mean amount of snowfall in 2080–2100, in the post-2100 period would lead to 10% or 20% more runoff under RCP4.5 and 5% or 10% under RCP8.5 because faster ice margin retreat and ice sheet loss under RCP8.5 dominate snowfall increases and ice elevation feedbacks. |
| first_indexed | 2024-03-10T04:35:47Z |
| format | Article |
| id | doaj.art-7d1dec195fd44df0a5c07be62ec69b1c |
| institution | Directory Open Access Journal |
| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-03-10T04:35:47Z |
| publishDate | 2021-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Atmosphere |
| spelling | doaj.art-7d1dec195fd44df0a5c07be62ec69b1c2023-11-23T03:45:33ZengMDPI AGAtmosphere2073-44332021-11-011212156910.3390/atmos12121569Greenland Ice Sheet Surface Runoff Projections to 2200 Using Degree-Day MethodsChao Yue0Liyun Zhao1Michael Wolovick2John C. Moore3College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, ChinaCollege of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, ChinaCollege of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, ChinaCollege of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, ChinaSurface runoff from the Greenland ice sheet (GrIS) has dominated recent ice mass loss and is having significant impacts on sea-level rise under global warming. Here, we used two modified degree-day (DD) methods to estimate the runoff of the GrIS during 1950–2200 under the extensions of historical, RCP 4.5, and RCP 8.5 scenarios. Near-surface air temperature and snowfall were obtained from five Earth System Models. We applied new degree-day factors to best match the results of the surface energy and mass balance model, SEMIC, over the whole GrIS in a 21st century simulation. The relative misfits between tuned DD methods and SEMIC during 2050–2089 were 3% (RCP4.5) and 12% (RCP8.5), much smaller than the 30% difference between untuned DD methods and SEMIC. Equilibrium line altitude evolution, runoff-elevation feedback, and ice mask evolution were considered in the future simulations to 2200. The ensemble mean cumulative runoff increasing over the GrIS was equivalent to sea-level rises of 6 ± 2 cm (RCP4.5) and 9 ± 3 cm (RCP8.5) by 2100 relative to the period 1950–2005, and 13 ± 4 cm (RCP4.5) and 40 ± 5 cm (RCP8.5) by 2200. Runoff-elevation feedback produced runoff increases of 5 ± 2% (RCP4.5) and 6 ± 2% (RCP8.5) by 2100, and 12 ± 4% (RCP4.5) and 15 ± 5% (RCP8.5) by 2200. Two sensitivity experiments showed that increases of 150% or 200%, relative to the annual mean amount of snowfall in 2080–2100, in the post-2100 period would lead to 10% or 20% more runoff under RCP4.5 and 5% or 10% under RCP8.5 because faster ice margin retreat and ice sheet loss under RCP8.5 dominate snowfall increases and ice elevation feedbacks.https://www.mdpi.com/2073-4433/12/12/1569Greenland ice sheetrunoffsea-leveldegree-day methodrunoff-elevation feedback |
| spellingShingle | Chao Yue Liyun Zhao Michael Wolovick John C. Moore Greenland Ice Sheet Surface Runoff Projections to 2200 Using Degree-Day Methods Atmosphere Greenland ice sheet runoff sea-level degree-day method runoff-elevation feedback |
| title | Greenland Ice Sheet Surface Runoff Projections to 2200 Using Degree-Day Methods |
| title_full | Greenland Ice Sheet Surface Runoff Projections to 2200 Using Degree-Day Methods |
| title_fullStr | Greenland Ice Sheet Surface Runoff Projections to 2200 Using Degree-Day Methods |
| title_full_unstemmed | Greenland Ice Sheet Surface Runoff Projections to 2200 Using Degree-Day Methods |
| title_short | Greenland Ice Sheet Surface Runoff Projections to 2200 Using Degree-Day Methods |
| title_sort | greenland ice sheet surface runoff projections to 2200 using degree day methods |
| topic | Greenland ice sheet runoff sea-level degree-day method runoff-elevation feedback |
| url | https://www.mdpi.com/2073-4433/12/12/1569 |
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