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Newsham KK, Davey ML, Hopkins DW, Dennis PG. Regional Diversity of Maritime Antarctic Soil Fungi and Predicted Responses of Guilds and Growth Forms to Climate Change. Front Microbiol 2021; 11:615659. [PMID: 33574801 PMCID: PMC7870798 DOI: 10.3389/fmicb.2020.615659] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 12/22/2020] [Indexed: 01/04/2023] Open
Abstract
We report a metabarcoding study documenting the fungal taxa in 29 barren fellfield soils sampled from along a 1,650 km transect encompassing almost the entire maritime Antarctic (60-72°S) and the environmental factors structuring the richness, relative abundance, and taxonomic composition of three guilds and growth forms. The richness of the lichenised fungal guild, which accounted for 19% of the total fungal community, was positively associated with mean annual surface air temperature (MASAT), with an increase of 1.7 operational taxonomic units (OTUs) of lichenised fungi per degree Celsius rise in air temperature. Soil Mn concentration, MASAT, C:N ratio, and pH value determined the taxonomic composition of the lichenised guild, and the relative abundance of the guild was best predicted by soil Mn concentration. There was a 3% decrease in the relative abundance of the saprotrophic fungal guild in the total community for each degree Celsius rise in air temperature, and the OTU richness of the guild, which accounted for 39% of the community, was negatively associated with Mn concentration. The taxonomic composition of the saprotrophic guild varied with MASAT, pH value, and Mn, NH4 +-N, and SO4 2- concentrations. The richness of the yeast community, which comprised 3% of the total fungal community, was positively associated with soil K concentration, with its composition being determined by C:N ratio. In contrast with a similar study in the Arctic, the relative abundance and richness of lichenised fungi declined between 60°S and 69°S, with those of saprotrophic Agaricales also declining sharply in soils beyond 63°S. Basidiomycota, which accounted for 4% of reads, were much less frequent than in vegetated soils at lower latitudes, with the Ascomycota (70% of reads) being the dominant phylum. We conclude that the richness, relative abundance, and taxonomic composition of guilds and growth forms of maritime Antarctic soil fungi are influenced by air temperature and edaphic factors, with implications for the soils of the region as its climate changes during the 21st century.
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Affiliation(s)
- Kevin K. Newsham
- British Antarctic Survey, Natural Environment Research Council, Cambridge, United Kingdom
| | - Marie L. Davey
- Norwegian Institute for Nature Research, Trondheim, Norway
| | | | - Paul G. Dennis
- School of Earth and Environmental Sciences, The University of Queensland, Brisbane, QLD, Australia
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Misiak M, Goodall‐Copestake WP, Sparks TH, Worland MR, Boddy L, Magan N, Convey P, Hopkins DW, Newsham KK. Inhibitory effects of climate change on the growth and extracellular enzyme activities of a widespread Antarctic soil fungus. GLOBAL CHANGE BIOLOGY 2020; 27:1111-1125. [PMID: 33230837 PMCID: PMC7898924 DOI: 10.1111/gcb.15456] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 10/22/2020] [Accepted: 11/14/2020] [Indexed: 06/01/2023]
Abstract
Temperatures approaching or exceeding 20°C have been measured during summer in polar regions at the surfaces of barren fellfield soils under cloudless skies around solar noon. However, despite the upper temperature limit for the growth of cold-adapted microbes-which are abundant in polar soils and have pivotal roles in nutrient cycling-typically being close to this temperature, previous studies have not addressed the consequences of climate change for the metabolism of these organisms in the natural environment. Here in a 5-year field experiment on Alexander Island in the southern maritime Antarctic, we show that the abundance of Pseudogymnoascus roseus, the most widespread decomposer fungus in maritime Antarctic fellfield soils, is reduced by 1-2 orders of magnitude when irrigated and nutrient-amended soils are warmed to >20°C during summer. Laboratory experiments under conditions mimicking those during midsummer in the natural environment indicated that the hyphal extension rates of P. roseus isolates and the activities of five extracellular enzymes are reduced by 54%-96% at high water availability after exposure to temperatures cycling daily from 2 to 21°C and 2 to 24°C, relative to temperatures cycling from 2 to 18°C. Given that the temperatures of surface soils at the study site already reach 19°C during midsummer, the observations reported here suggest that, at predicted rates of warming arising from moderate greenhouse gas emissions, inhibitory effects of climate change on the metabolism of P. roseus could manifest themselves within the next few decades. Furthermore, with peak temperatures at the surfaces of fellfield soils at other maritime Antarctic locations and in High Arctic and alpine regions already exceeding 20°C during summer, the observations suggest that climate warming has the potential to inhibit the growth of other cold-adapted microbes, with negative effects on soils as the Earth's climate continues to warm.
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Affiliation(s)
- Marta Misiak
- British Antarctic SurveyNERCCambridgeUK
- Cardiff School of BiosciencesCardiffUK
| | - William P. Goodall‐Copestake
- British Antarctic SurveyNERCCambridgeUK
- Present address:
Scottish Association for Marine ScienceObanArgyllPA37 1QAUK
| | - Tim H. Sparks
- Institute of ZoologyPoznań University of Life SciencesPoznańPoland
- Museum of ZoologyUniversity of CambridgeCambridgeUK
| | | | | | - Naresh Magan
- Applied Mycology Group, Environment and AgriFood ThemeCranfield UniversityCranfieldUK
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da Rosa CN, Bremer UF, Pereira Filho W, Sousa Júnior MA, Kramer G, Hillebrand FL, de Jesus JB. Freezing and thawing of lakes on the Nelson and King George Islands, Antarctic, using Sentinel 1A synthetic aperture radar images. ENVIRONMENTAL MONITORING AND ASSESSMENT 2020; 192:559. [PMID: 32747987 DOI: 10.1007/s10661-020-08526-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 07/27/2020] [Indexed: 06/11/2023]
Abstract
This article aims to analyze the dynamics of freezing and thawing of Antarctic lakes located in ice-free areas on Nelson Island and Fildes Peninsula, where response to changes in air temperature and precipitation rates occur rapidly, during the period from July 2016 to December 2018. In these places, which are difficult to access, remote sensing is an important alternative, especially considering the use of active remote sensors such as the Synthetic Aperture Radar (SAR), which has less restriction regarding the presence of clouds over the study area. Three backscatter thresholds were defined (σ) for the identification of the physical state of the water of the lakes of the study region, applied in Sentinel 1A SAR (S1A) images under Horizontal Horizontal (HH) polarization and Interferometric Wide (IW) imaging mode. These images, along with the air temperature data obtained by the Interim Re-Analysis (ERA-Interim) atmospheric reanalysis model, provided the evidence for the interpretation of the freezing and thawing periods of the lakes. The thresholds applied for the definition of the physical state of the lake water were greater than - 14 dB for frozen water, between - 14 and - 17 dB for the surface, with up to 60% of their frozen area, and less than - 17 dB for open water. The temporal analysis revealed that the lakes start to thaw in October, become completely thawed in February, and freeze again in March. Nevertheless, it can be said that the S1A satellite allows a satisfactory identification of the liquid and solid phases of the water in the lakes of the study region.
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Affiliation(s)
- Cristiano Niederauer da Rosa
- Polar and Climate Center, Postgraduate Program in Remote Sensing, Federal University of Rio Grande do Sul-UFRGS, Avenida Bento Gonçalves, 9500, Building 43136, rooms 208 and 210, Porto Alegre, Rio Grande do Sul, 91501-970, Brazil.
| | - Ulisses Franz Bremer
- Polar and Climate Center, Postgraduate Program in Remote Sensing, Federal University of Rio Grande do Sul-UFRGS, Avenida Bento Gonçalves, 9500, Building 43136, rooms 208 and 210, Porto Alegre, Rio Grande do Sul, 91501-970, Brazil
| | - Waterloo Pereira Filho
- Department of Geosciences, Federal University of Santa Maria, Av. Roraima, 1000, Santa Maria, Rio Grande do Sul., 97105-900, Brazil
| | - Manoel Araujo Sousa Júnior
- Department of Rural Engineering, Federal University of Santa Maria, Av. Roraima, 1000, Santa Maria, Rio Grande do Sul, 97105-900, Brazil
| | - Gisieli Kramer
- Postgraduate Program in Geography, Federal University of Santa Maria, Av. Roraima, 1000, Santa Maria, Rio Grande do Sul, 97105-900, Brazil
| | - Fernando Luis Hillebrand
- Polar and Climate Center, Postgraduate Program in Remote Sensing, Federal University of Rio Grande do Sul-UFRGS, Avenida Bento Gonçalves, 9500, Building 43136, rooms 208 and 210, Porto Alegre, Rio Grande do Sul, 91501-970, Brazil
| | - Janisson Batista de Jesus
- Postgraduate Program in Remote Sensing, Federal University of Rio Grande do Sul, Avenida Bento Gonçalves, 9500, Porto Alegre, Rio Grande do Sul, 91501-970, Brazil
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Comparison of Diatom Paleo-Assemblages with Adjacent Limno-Terrestrial Communities on Vega Island, Antarctic Peninsula. WATER 2020. [DOI: 10.3390/w12051340] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Diatoms are useful ecological and paleolimnological indicators routinely used to reconstruct past conditions and monitor environmental change. Despite this, diatom assemblages from lake sediment cores are often difficult to interpret due to a limited knowledge of the ecology of some species, some of which may originate from the adjacent limno-terrestrial landscape. Here, we compare diatom assemblages from two recently published Antarctic lake sediment cores collected from the northeast and southwest sides of Vega Island, Antarctic Peninsula. We further compare the sediment core assemblages with adjacent modern communities inhabiting four different limno-terrestrial habitat types to gauge the importance of landscape connectivity in determining paleo-assemblage structure. We found that diatom assemblage composition was significantly different between the two cores, and our survey of modern habitats further revealed habitat type to be an important factor determining the composition of limno-terrestrial samples. Differences in modern habitats were driven primarily by Chamaepinnularia krookiformis in mosses, Nitzschia paleacea in ponds, and Fistulifera pelliculosa in streams. When modern communities were compared with paleo-assemblages through ordination, the cored lake from the northeast side, which exhibited greater hydrological connectivity with its surroundings, clustered more closely with the adjacent modern samples. Meanwhile, the cored lake from the southwest side, which was more hydrologically isolated, formed a distinct cluster separate from the others. Overall, species richness and diversity were greater on the southwest side of the island than the northeast, and the known distributions of diatom taxa supported the notion that Vega Island was a transitional zone between the Maritime and Continental Antarctic bioregions. These results collectively suggested that while environmental and spatial controls may be influential in determining diatom community composition, the unique hydrogeological setting of individual waterbodies was an important consideration for determining the assemblage structure of lake cores. This paper furthermore expanded ongoing research of diatom diversity and distributions on maritime Antarctic islands, which will improve diatom-based interpretations for regional ecological monitoring and paleolimnology in the future.
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Lenaerts JTM, Medley B, van den Broeke MR, Wouters B. Observing and Modeling Ice Sheet Surface Mass Balance. REVIEWS OF GEOPHYSICS (WASHINGTON, D.C. : 1985) 2019; 57:376-420. [PMID: 31598609 PMCID: PMC6774314 DOI: 10.1029/2018rg000622] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 03/17/2019] [Accepted: 03/19/2019] [Indexed: 06/10/2023]
Abstract
Surface mass balance (SMB) provides mass input to the surface of the Antarctic and Greenland Ice Sheets and therefore comprises an important control on ice sheet mass balance and resulting contribution to global sea level change. As ice sheet SMB varies highly across multiple scales of space (meters to hundreds of kilometers) and time (hourly to decadal), it is notoriously challenging to observe and represent in models. In addition, SMB consists of multiple components, all of which depend on complex interactions between the atmosphere and the snow/ice surface, large-scale atmospheric circulation and ocean conditions, and ice sheet topography. In this review, we present the state-of-the-art knowledge and recent advances in ice sheet SMB observations and models, highlight current shortcomings, and propose future directions. Novel observational methods allow mapping SMB across larger areas, longer time periods, and/or at very high (subdaily) temporal frequency. As a recent observational breakthrough, cosmic ray counters provide direct estimates of SMB, circumventing the need for accurate snow density observations upon which many other techniques rely. Regional atmospheric climate models have drastically improved their simulation of ice sheet SMB in the last decade, thanks to the inclusion or improved representation of essential processes (e.g., clouds, blowing snow, and snow albedo), and by enhancing horizontal resolution (5-30 km). Future modeling efforts are required in improving Earth system models to match regional atmospheric climate model performance in simulating ice sheet SMB, and in reinforcing the efforts in developing statistical and dynamic downscaling to represent smaller-scale SMB processes.
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Affiliation(s)
- Jan T. M. Lenaerts
- Department of Atmospheric and Oceanic SciencesUniversity of Colorado BoulderBoulderCOUSA
| | - Brooke Medley
- Cryospheric Sciences LaboratoryNASA GSFCGoddardMDUSA
| | | | - Bert Wouters
- Institute for Marine and Atmospheric ResearchUtrecht UniversityUtrechtThe Netherlands
- Faculty of Civil Engineering and GeosciencesDelft University of TechnologyDelftThe Netherlands
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Bokhorst S, Convey P, Aerts R. Nitrogen Inputs by Marine Vertebrates Drive Abundance and Richness in Antarctic Terrestrial Ecosystems. Curr Biol 2019; 29:1721-1727.e3. [PMID: 31080085 DOI: 10.1016/j.cub.2019.04.038] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 03/07/2019] [Accepted: 04/12/2019] [Indexed: 11/30/2022]
Abstract
Biodiversity is threatened by climate change and other human activities [1], but to assess impacts, we also need to identify the current distribution of species on Earth. Predicting abundance and richness patterns is difficult in many regions and especially so on the remote Antarctic continent, due to periods of snow cover, which limit remote sensing, and the small size of the biota present. As the Earth's coldest continent, temperature and water availability have received particular attention in understanding patterns of Antarctic biodiversity [2], whereas nitrogen availability has received less attention [3]. Nitrogen input by birds is a major nutrient source in many regions on Earth [4-7], and input from penguins and seals is associated with increased plant growth [8-10] and soil respiration [11-13] at some Antarctic locations. However, the consequences of increased nitrogen concentrations in Antarctic mosses and lichens for their associated food web has hardly been addressed [14, 15], despite the fact that nutrient status of primary producers affects the abundance and diversity of higher trophic levels [16, 17]. We show that nitrogen input and δ15N signatures from marine vertebrates are associated with terrestrial biodiversity hotspots well beyond (>1,000 m) their immediate colony borders along the Antarctic Peninsula. Invertebrate abundance and richness was two to eight times higher under penguin and elephant seal influence. The nitrogen footprint area was correlated with the vertebrate population size. These findings improve our ability to predict biogeographical patterns of Antarctic terrestrial biodiversity through knowledge of the location and size of penguin and elephant seal concentrations.
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Affiliation(s)
- Stef Bokhorst
- Department of Ecological Science, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, the Netherlands.
| | - Peter Convey
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET, UK
| | - Rien Aerts
- Department of Ecological Science, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, the Netherlands
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Sáez PL, Bravo LA, Cavieres LA, Vallejos V, Sanhueza C, Font-Carrascosa M, Gil-Pelegrín E, Javier Peguero-Pina J, Galmés J. Photosynthetic limitations in two Antarctic vascular plants: importance of leaf anatomical traits and Rubisco kinetic parameters. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:2871-2883. [PMID: 28830100 PMCID: PMC5854023 DOI: 10.1093/jxb/erx148] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 04/07/2017] [Indexed: 05/05/2023]
Abstract
Particular physiological traits allow the vascular plants Deschampsia antarctica Desv. and Colobanthus quitensis (Kunth) Bartl. to inhabit Antarctica. The photosynthetic performance of these species was evaluated in situ, focusing on diffusive and biochemical constraints to CO2 assimilation. Leaf gas exchange, Chl a fluorescence, leaf ultrastructure, and Rubisco catalytic properties were examined in plants growing on King George and Lagotellerie islands. In spite of the species- and population-specific effects of the measurement temperature on the main photosynthetic parameters, CO2 assimilation was highly limited by CO2 diffusion. In particular, the mesophyll conductance (gm)-estimated from both gas exchange and leaf chlorophyll fluorescence and modeled from leaf anatomy-was remarkably low, restricting CO2 diffusion and imposing the strongest constraint to CO2 acquisition. Rubisco presented a high specificity for CO2 as determined in vitro, suggesting a tight co-ordination between CO2 diffusion and leaf biochemistry that may be critical ultimately to optimize carbon balance in these species. Interestingly, both anatomical and biochemical traits resembled those described in plants from arid environments, providing a new insight into plant functional acclimation to extreme conditions. Understanding what actually limits photosynthesis in these species is important to anticipate their responses to the ongoing and predicted rapid warming in the Antarctic Peninsula.
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Affiliation(s)
- Patricia L Sáez
- Laboratorio Cultivo de Tejidos Vegetales, Centro de Biotecnología, Departamento de Silvicultura, Facultad de Ciencias Forestales, Universidad de Concepción, Concepción, Chile
| | - León A Bravo
- Laboratorio de Fisiología y Biología Molecular Vegetal, Instituto de Agroindustria, Departamento de Ciencias Agronómicas y Recursos Naturales, Facultad de Ciencias Agropecuarias y Forestales, Center of Plant, Soil Interaction and Natural Resources Biotechnology, Scientific and Technological Bioresource Nucleus, Universidad de La Frontera, Temuco, Chile
| | - Lohengrin A Cavieres
- Laboratorio de ECOBIOSIS, Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Barrio Universitario s/n, Concepción, Chile
| | - Valentina Vallejos
- Laboratorio Cultivo de Tejidos Vegetales, Centro de Biotecnología, Departamento de Silvicultura, Facultad de Ciencias Forestales, Universidad de Concepción, Concepción, Chile
| | - Carolina Sanhueza
- Laboratorio de ECOBIOSIS, Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Barrio Universitario s/n, Concepción, Chile
| | - Marcel Font-Carrascosa
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears-INAGEA, Balearic Islands, Spain
| | - Eustaquio Gil-Pelegrín
- Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria, Gobierno de Aragón, Zaragoza, Spain
| | - José Javier Peguero-Pina
- Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria, Gobierno de Aragón, Zaragoza, Spain
| | - Jeroni Galmés
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears-INAGEA, Balearic Islands, Spain
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Antarctic Peninsula Climate Variability and Its Causes as Revealed by Analysis of Instrumental Records. ACTA ACUST UNITED AC 2013. [DOI: 10.1029/ar079p0017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
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9
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Bokhorst S, Huiskes A, Convey P, Aerts R. External nutrient inputs into terrestrial ecosystems of the Falkland Islands and the Maritime Antarctic region. Polar Biol 2007. [DOI: 10.1007/s00300-007-0292-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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10
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van den Broeke M, van de Berg WJ, van Meijgaard E, Reijmer C. Identification of Antarctic ablation areas using a regional atmospheric climate model. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2006jd007127] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Wingham DJ, Shepherd A, Muir A, Marshall GJ. Mass balance of the Antarctic ice sheet. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2006; 364:1627-35. [PMID: 16782603 DOI: 10.1098/rsta.2006.1792] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The Antarctic contribution to sea-level rise has long been uncertain. While regional variability in ice dynamics has been revealed, a picture of mass changes throughout the continental ice sheet is lacking. Here, we use satellite radar altimetry to measure the elevation change of 72% of the grounded ice sheet during the period 1992-2003. Depending on the density of the snow giving rise to the observed elevation fluctuations, the ice sheet mass trend falls in the range -5-+85Gtyr-1. We find that data from climate model reanalyses are not able to characterise the contemporary snowfall fluctuation with useful accuracy and our best estimate of the overall mass trend-growth of 27+/-29Gtyr-1-is based on an assessment of the expected snowfall variability. Mass gains from accumulating snow, particularly on the Antarctic Peninsula and within East Antarctica, exceed the ice dynamic mass loss from West Antarctica. The result exacerbates the difficulty of explaining twentieth century sea-level rise.
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Affiliation(s)
- D J Wingham
- University College London, Centre for Polar Observation and Modelling, Gower Street, London WC1E 6BT, UK.
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Rignot E. Changes in ice dynamics and mass balance of the Antarctic ice sheet. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2006; 364:1637-55. [PMID: 16782604 DOI: 10.1098/rsta.2006.1793] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The concept that the Antarctic ice sheet changes with eternal slowness has been challenged by recent observations from satellites. Pronounced regional warming in the Antarctic Peninsula triggered ice shelf collapse, which led to a 10-fold increase in glacier flow and rapid ice sheet retreat. This chain of events illustrated the vulnerability of ice shelves to climate warming and their buffering role on the mass balance of Antarctica. In West Antarctica, the Pine Island Bay sector is draining far more ice into the ocean than is stored upstream from snow accumulation. This sector could raise sea level by 1m and trigger widespread retreat of ice in West Antarctica. Pine Island Glacier accelerated 38% since 1975, and most of the speed up took place over the last decade. Its neighbour Thwaites Glacier is widening up and may double its width when its weakened eastern ice shelf breaks up. Widespread acceleration in this sector may be caused by glacier ungrounding from ice shelf melting by an ocean that has recently warmed by 0.3 degrees C. In contrast, glaciers buffered from oceanic change by large ice shelves have only small contributions to sea level. In East Antarctica, many glaciers are close to a state of mass balance, but sectors grounded well below sea level, such as Cook Ice Shelf, Ninnis/Mertz, Frost and Totten glaciers, are thinning and losing mass. Hence, East Antarctica is not immune to changes.
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Affiliation(s)
- Eric Rignot
- Jet Propulsion Laboratory 4800 Oak Grove Drive MS 300-319, Pasadena, CA 91109-8099, USA.
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van de Berg WJ, van den Broeke MR, Reijmer CH, van Meijgaard E. Reassessment of the Antarctic surface mass balance using calibrated output of a regional atmospheric climate model. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jd006495] [Citation(s) in RCA: 225] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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14
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Ó Cofaigh C, Larter RD, Dowdeswell JA, Hillenbrand CD, Pudsey CJ, Evans J, Morris P. Flow of the West Antarctic Ice Sheet on the continental margin of the Bellingshausen Sea at the Last Glacial Maximum. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2005jb003619] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Colm Ó Cofaigh
- Department of Geography; University of Durham; Durham UK
| | | | | | | | | | - Jeffrey Evans
- Scott Polar Research Institute; University of Cambridge; Cambridge UK
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Bacak A, Bardwell MW, Raventos MT, Percival CJ, Sanchez-Reyna G, Shallcross DE. Kinetics of the Reaction of CH3O2 + NO: A Temperature and Pressure Dependence Study with Chemical Ionization Mass Spectrometry. J Phys Chem A 2004. [DOI: 10.1021/jp047764b] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Asan Bacak
- The School of Science, The Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, United Kingdom, and Biogeochemistry Research Centre, School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Max W. Bardwell
- The School of Science, The Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, United Kingdom, and Biogeochemistry Research Centre, School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - M. Teresa Raventos
- The School of Science, The Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, United Kingdom, and Biogeochemistry Research Centre, School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Carl J. Percival
- The School of Science, The Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, United Kingdom, and Biogeochemistry Research Centre, School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Gabriela Sanchez-Reyna
- The School of Science, The Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, United Kingdom, and Biogeochemistry Research Centre, School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Dudley E. Shallcross
- The School of Science, The Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, United Kingdom, and Biogeochemistry Research Centre, School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
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van Lipzig NPM. Precipitation, sublimation, and snow drift in the Antarctic Peninsula region from a regional atmospheric model. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2004jd004701] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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17
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Box JE. Greenland ice sheet surface mass balance 1991–2000: Application of Polar MM5 mesoscale model and in situ data. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2003jd004451] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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