A model of the weathering crust and microbial activity on an ice-sheet surface
<p>Shortwave radiation penetrating beneath an ice-sheet surface can cause internal melting and the formation of a near-surface porous layer known as the weathering crust, a dynamic hydrological system that provides home to impurities and microbial life. We develop a mathematical model, incorp...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-05-01
|
| Series: | The Cryosphere |
| Online Access: | https://tc.copernicus.org/articles/17/1967/2023/tc-17-1967-2023.pdf |
| _version_ | 1797829751478419456 |
|---|---|
| author | T. Woods I. J. Hewitt |
| author_facet | T. Woods I. J. Hewitt |
| author_sort | T. Woods |
| collection | DOAJ |
| description | <p>Shortwave radiation penetrating beneath an ice-sheet surface can cause internal melting and the formation of a near-surface porous layer known as the weathering crust, a dynamic hydrological system that provides home to impurities and microbial life. We develop a mathematical model, incorporating thermodynamics and population dynamics, for the evolution of such layers. The model accounts for conservation of mass and energy, for internal and surface-absorbed radiation, and for logistic growth of a microbial species mediated by nutrients that are sourced from the melting ice. It also accounts for potential melt–albedo and microbe–albedo feedbacks, through the dependence of the absorption coefficient on the porosity or microbial concentration. We investigate one-dimensional steadily melting solutions of the model, which give rise to predictions for the weathering crust depth, water content, melt rate, and microbial abundance, depending on a number of parameters. In particular, we examine how these quantities depend on the forcing energy fluxes, finding that the relative amounts of shortwave (surface-penetrating) radiation and other heat fluxes are particularly important in determining the structure of the weathering crust. The results explain why weathering crusts form and disappear under different forcing conditions and suggest a range of possible changes in behaviour in response to climate change.</p> |
| first_indexed | 2024-04-09T13:26:15Z |
| format | Article |
| id | doaj.art-510a17af044a497895966433c15c0dcc |
| institution | Directory Open Access Journal |
| issn | 1994-0416 1994-0424 |
| language | English |
| last_indexed | 2024-04-09T13:26:15Z |
| publishDate | 2023-05-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | The Cryosphere |
| spelling | doaj.art-510a17af044a497895966433c15c0dcc2023-05-10T10:27:12ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242023-05-01171967198710.5194/tc-17-1967-2023A model of the weathering crust and microbial activity on an ice-sheet surfaceT. WoodsI. J. Hewitt<p>Shortwave radiation penetrating beneath an ice-sheet surface can cause internal melting and the formation of a near-surface porous layer known as the weathering crust, a dynamic hydrological system that provides home to impurities and microbial life. We develop a mathematical model, incorporating thermodynamics and population dynamics, for the evolution of such layers. The model accounts for conservation of mass and energy, for internal and surface-absorbed radiation, and for logistic growth of a microbial species mediated by nutrients that are sourced from the melting ice. It also accounts for potential melt–albedo and microbe–albedo feedbacks, through the dependence of the absorption coefficient on the porosity or microbial concentration. We investigate one-dimensional steadily melting solutions of the model, which give rise to predictions for the weathering crust depth, water content, melt rate, and microbial abundance, depending on a number of parameters. In particular, we examine how these quantities depend on the forcing energy fluxes, finding that the relative amounts of shortwave (surface-penetrating) radiation and other heat fluxes are particularly important in determining the structure of the weathering crust. The results explain why weathering crusts form and disappear under different forcing conditions and suggest a range of possible changes in behaviour in response to climate change.</p>https://tc.copernicus.org/articles/17/1967/2023/tc-17-1967-2023.pdf |
| spellingShingle | T. Woods I. J. Hewitt A model of the weathering crust and microbial activity on an ice-sheet surface The Cryosphere |
| title | A model of the weathering crust and microbial activity on an ice-sheet surface |
| title_full | A model of the weathering crust and microbial activity on an ice-sheet surface |
| title_fullStr | A model of the weathering crust and microbial activity on an ice-sheet surface |
| title_full_unstemmed | A model of the weathering crust and microbial activity on an ice-sheet surface |
| title_short | A model of the weathering crust and microbial activity on an ice-sheet surface |
| title_sort | model of the weathering crust and microbial activity on an ice sheet surface |
| url | https://tc.copernicus.org/articles/17/1967/2023/tc-17-1967-2023.pdf |
| work_keys_str_mv | AT twoods amodeloftheweatheringcrustandmicrobialactivityonanicesheetsurface AT ijhewitt amodeloftheweatheringcrustandmicrobialactivityonanicesheetsurface AT twoods modeloftheweatheringcrustandmicrobialactivityonanicesheetsurface AT ijhewitt modeloftheweatheringcrustandmicrobialactivityonanicesheetsurface |