{"title":"莱德冰川冰舌下的基础融化速率和海洋环流及其对气候变暖的响应:高分辨率模型研究","authors":"Jonathan Wiskandt, I. Koszalka, J. Nilsson","doi":"10.5194/tc-17-2755-2023","DOIUrl":null,"url":null,"abstract":"Abstract. The oceanic forcing of basal melt under floating ice shelves in Greenland and Antarctica is one of the major sources of uncertainty in climate ice\nsheet modelling. We use a high-resolution, nonhydrostatic configuration of the Massachusetts Institute of Technology general circulation model\n(MITgcm) to investigate basal melt rates and melt-driven circulation in the Sherard Osborn Fjord under the floating tongue of Ryder Glacier,\nnorthwestern Greenland. The control model configuration, based on the first-ever observational survey by Ryder 2019 Expedition, yielded\nmelt rates consistent with independent satellite estimates. A protocol of model sensitivity experiments quantified the response to oceanic thermal\nforcing due to warming Atlantic Water and to the buoyancy input from the subglacial discharge of surface fresh water. We found that the average\nbasal melt rates show a nonlinear response to oceanic forcing in the lower range of ocean temperatures, while the response becomes indistinguishable\nfrom linear for higher ocean temperatures, which unifies the results from previous modelling studies of other marine-terminating glaciers. The melt\nrate response to subglacial discharge is sublinear, consistent with other studies. The melt rates and circulation below the ice tongue exhibit a\nspatial pattern that is determined by the ambient density stratification.\n","PeriodicalId":56315,"journal":{"name":"Cryosphere","volume":null,"pages":null},"PeriodicalIF":4.4000,"publicationDate":"2023-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Basal melt rates and ocean circulation under the Ryder Glacier ice tongue and their response to climate warming: a high-resolution modelling study\",\"authors\":\"Jonathan Wiskandt, I. Koszalka, J. Nilsson\",\"doi\":\"10.5194/tc-17-2755-2023\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Abstract. The oceanic forcing of basal melt under floating ice shelves in Greenland and Antarctica is one of the major sources of uncertainty in climate ice\\nsheet modelling. We use a high-resolution, nonhydrostatic configuration of the Massachusetts Institute of Technology general circulation model\\n(MITgcm) to investigate basal melt rates and melt-driven circulation in the Sherard Osborn Fjord under the floating tongue of Ryder Glacier,\\nnorthwestern Greenland. The control model configuration, based on the first-ever observational survey by Ryder 2019 Expedition, yielded\\nmelt rates consistent with independent satellite estimates. A protocol of model sensitivity experiments quantified the response to oceanic thermal\\nforcing due to warming Atlantic Water and to the buoyancy input from the subglacial discharge of surface fresh water. We found that the average\\nbasal melt rates show a nonlinear response to oceanic forcing in the lower range of ocean temperatures, while the response becomes indistinguishable\\nfrom linear for higher ocean temperatures, which unifies the results from previous modelling studies of other marine-terminating glaciers. The melt\\nrate response to subglacial discharge is sublinear, consistent with other studies. The melt rates and circulation below the ice tongue exhibit a\\nspatial pattern that is determined by the ambient density stratification.\\n\",\"PeriodicalId\":56315,\"journal\":{\"name\":\"Cryosphere\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.4000,\"publicationDate\":\"2023-07-13\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Cryosphere\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.5194/tc-17-2755-2023\",\"RegionNum\":2,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"GEOGRAPHY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Cryosphere","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.5194/tc-17-2755-2023","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOGRAPHY, PHYSICAL","Score":null,"Total":0}
Basal melt rates and ocean circulation under the Ryder Glacier ice tongue and their response to climate warming: a high-resolution modelling study
Abstract. The oceanic forcing of basal melt under floating ice shelves in Greenland and Antarctica is one of the major sources of uncertainty in climate ice
sheet modelling. We use a high-resolution, nonhydrostatic configuration of the Massachusetts Institute of Technology general circulation model
(MITgcm) to investigate basal melt rates and melt-driven circulation in the Sherard Osborn Fjord under the floating tongue of Ryder Glacier,
northwestern Greenland. The control model configuration, based on the first-ever observational survey by Ryder 2019 Expedition, yielded
melt rates consistent with independent satellite estimates. A protocol of model sensitivity experiments quantified the response to oceanic thermal
forcing due to warming Atlantic Water and to the buoyancy input from the subglacial discharge of surface fresh water. We found that the average
basal melt rates show a nonlinear response to oceanic forcing in the lower range of ocean temperatures, while the response becomes indistinguishable
from linear for higher ocean temperatures, which unifies the results from previous modelling studies of other marine-terminating glaciers. The melt
rate response to subglacial discharge is sublinear, consistent with other studies. The melt rates and circulation below the ice tongue exhibit a
spatial pattern that is determined by the ambient density stratification.
期刊介绍:
The Cryosphere (TC) is a not-for-profit international scientific journal dedicated to the publication and discussion of research articles, short communications, and review papers on all aspects of frozen water and ground on Earth and on other planetary bodies.
The main subject areas are the following:
ice sheets and glaciers;
planetary ice bodies;
permafrost and seasonally frozen ground;
seasonal snow cover;
sea ice;
river and lake ice;
remote sensing, numerical modelling, in situ and laboratory studies of the above and including studies of the interaction of the cryosphere with the rest of the climate system.