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Tiny samples of ancient atmosphere in air bubbles within ice cores contain argon (Ar), which can be used to reconstruct past temperature changes. At a sufficient depth, the air bubbles are compressed by the overburden pressure under low temperature and transform into air-hydrate crystals. While the oxygen (O2) and nitrogen (N2) molecules have indeed been identified in the air-hydrate crystals with Raman spectroscopy, direct observational knowledge of the distribution of Ar at depth within ice sheet and its enclathration has been lacking. In this study, we applied scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) to five air-hydrate crystals in the Greenland NEEM ice core, finding them to contain Ar and N. Given that Ar cannot be detected by Raman spectroscopy, the method commonly used for O2 and N2, the SEM-EDS measurement method may become increasingly useful for measuring inert gases in deep ice cores.

Tiny samples of ancient atmosphere in air bubbles within ice cores contain argon (Ar), which can be used to reconstruct past temperature changes. At a sufficient depth, the air bubbles are compressed by the overburden pressure under low temperature and transform into air-hydrate crystals. While the oxygen (O-2) and nitrogen (N-2) molecules have indeed been identified in the air-hydrate crystals with Raman spectroscopy, direct observational knowledge of the distribution of Ar at depth within ice sheet and its enclathration has been lacking. In this study, we applied scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) to five air-hydrate crystals in the Greenland NEEM ice core, finding them to contain Ar and N. Given that Ar cannot be detected by Raman spectroscopy, the method commonly used for O-2 and N-2, the SEM-EDS measurement method may become increasingly useful for measuring inert gases in deep ice cores.

Tiny samples of ancient atmosphere in air bubbles within ice cores contain argon (Ar), which can be used to reconstruct past temperature changes. At a sufficient depth, the air bubbles are compressed by the overburden pressure under low temperature and transform into air-hydrate crystals. While the oxygen (O-2) and nitrogen (N-2) molecules have indeed been identified in the air-hydrate crystals with Raman spectroscopy, direct observational knowledge of the distribution of Ar at depth within ice sheet and its enclathration has been lacking. In this study, we applied scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) to five air-hydrate crystals in the Greenland NEEM ice core, finding them to contain Ar and N. Given that Ar cannot be detected by Raman spectroscopy, the method commonly used for O-2 and N-2, the SEM-EDS measurement method may become increasingly useful for measuring inert gases in deep ice cores.

Tiny samples of ancient atmosphere in air bubbles within ice cores contain argon (Ar), which can be used to reconstruct past temperature changes. At a sufficient depth, the air bubbles are compressed by the overburden pressure under low temperature and transform into air-hydrate crystals. While the oxygen (O2) and nitrogen (N2) molecules have indeed been identified in the air-hydrate crystals with Raman spectroscopy, direct observational knowledge of the distribution of Ar at depth within ice sheet and its enclathration has been lacking. In this study, we applied scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) to five air-hydrate crystals in the Greenland NEEM ice core, finding them to contain Ar and N. Given that Ar cannot be detected by Raman spectroscopy, the method commonly used for O2 and N2, the SEM-EDS measurement method may become increasingly useful for measuring inert gases in deep ice cores.

We review major scientific results from Subtheme (1) "Variability of the Greenland Ice Sheet and climate" under Research Theme 2 "Variations in the ice sheet, glaciers, and the environment in the Greenland region" of the Arctic Challenge for Sustainability (ArCS) project. We participated in the international East Greenland Ice Core Project (EGRIP) led by Denmark, conducted snow pit observations near the coring site and reconstructed the surface mass balance over the past 10 years. Analyses of an ice core from Northwest Greenland revealed temporal variability in black carbon concentration over the past 350 years and in mineral dust over the past 100 years. To understand the mechanisms of ice-sheet flow, which is necessary for accurate predictions of sea level rise, we conducted laboratory experiments using artificial ice and derived an improved flow law for ice containing impurities. Ice sheet modeling was improved by including effects of impurities and ice stream dynamics. As part of the Ice Sheet Model Intercomparison Project for the Coupled Model Intercomparison Project Phase 6 (ISMIP6), we simulated ice sheet mass loss and contribution to sea level rise over the 21st century and beyond. Furthermore, we developed a Glacial Isostatic Adjustment model to better constrain ice sheet models.

We review major scientific results from Subtheme (1) "Variability of the Greenland Ice Sheet and climate" under Research Theme 2 "Variations in the ice sheet, glaciers, and the environment in the Greenland region" of the Arctic Challenge for Sustainability (ArCS) project. We participated in the international East Greenland Ice Core Project (EGRIP) led by Denmark, conducted snow pit observations near the coring site and reconstructed the surface mass balance over the past 10 years. Analyses of an ice core from Northwest Greenland revealed temporal variability in black carbon concentration over the past 350 years and in mineral dust over the past 100 years. To understand the mechanisms of ice-sheet flow, which is necessary for accurate predictions of sea level rise, we conducted laboratory experiments using artificial ice and derived an improved flow law for ice containing impurities. Ice sheet modeling was improved by including effects of impurities and ice stream dynamics. As part of the Ice Sheet Model Intercomparison Project for the Coupled Model Intercomparison Project Phase 6 (ISMIP6), we simulated ice sheet mass loss and contribution to sea level rise over the 21st century and beyond. Furthermore, we developed a Glacial Isostatic Adjustment model to better constrain ice sheet models.

We review major scientific results from Subtheme (1) "Variability of the Greenland Ice Sheet and climate" under Research Theme 2 "Variations in the ice sheet, glaciers, and the environment in the Greenland region" of the Arctic Challenge for Sustainability (ArCS) project. We participated in the international East Greenland Ice Core Project (EGRIP) led by Denmark, conducted snow pit observations near the coring site and reconstructed the surface mass balance over the past 10 years. Analyses of an ice core from Northwest Greenland revealed temporal variability in black carbon concentration over the past 350 years and in mineral dust over the past 100 years. To understand the mechanisms of ice-sheet flow, which is necessary for accurate predictions of sea level rise, we conducted laboratory experiments using artificial ice and derived an improved flow law for ice containing impurities. Ice sheet modeling was improved by including effects of impurities and ice stream dynamics. As part of the Ice Sheet Model Intercomparison Project for the Coupled Model Intercomparison Project Phase 6 (ISMIP6), we simulated ice sheet mass loss and contribution to sea level rise over the 21st century and beyond. Furthermore, we developed a Glacial Isostatic Adjustment model to better constrain ice sheet models.

We collected snow samples from two pits with depths of 4.02 and 3.18 m at the East Greenland Ice Core Project camp (75?37?N, 35?59?W), Greenland in the summer of 2016 to estimate recent annual snow deposition and examine seasonal variation in major ion species, stable isotopes of water and microparticles (dust). Dating based on clear seasonal variation in chemical components indicated that the 4.02- and 3.18-m-deep pits included snow deposition corresponding to ten years from 2006 to 2016 and seven years from 2009 to 2016, respectively. The mean values for annual snow deposition for the 4.02-m-deep pit were 138 and 145 mm yr? 1 in water equivalent (mm w.e. Yr? 1) in 2006?2016 and 2009?2016, respectively. The average deposition for the 3.18-m-deep pit was 149 mm w.e. Yr? 1 between 2009 and 2016. Seasonal variation in concentrations of major ion species and dust were similar to those previously reported for Greenland. The maximum Cl-/Na+ concentration ratios in the summer were much higher than the ratios at other sites in Greenland.

The limited number of surface mass balance (SMB) observations in the Antarctic inland hampers estimates of ice-sheet contribution to global sea level and locations with million-year-old ice. We present finely resolved SMB over the past three centuries in a low-accumulation region with significant depth hoar formation on Dome Fuji derived from ∼1,100 km of microwave radar stratigraphy dated with a firn core. The regional-mean SMB over the past 264 years is estimated to ∼22.5 ± 3.3 kg m−2 a−1, but with large local variability of up to 30%. We found that local SMB is negatively correlated with surface slope at scales of a few hundred meters, resulting in anomalous zones of low SMB which represent as much as 8–10% of the total SMB on the inland plateau if the SMB-slope relationship is more widely valid. This impact should be investigated further to improve estimates of Antarctic mass balance and sea-level contribution., SCOPUS: le.j, info:eu-repo/semantics/published

We collected snow samples from two pits with depths of 4.02 and 3.18 m at the East Greenland Ice Core Project camp (75?37?N, 35?59?W), Greenland in the summer of 2016 to estimate recent annual snow deposition and examine seasonal variation in major ion species, stable isotopes of water and microparticles (dust). Dating based on clear seasonal variation in chemical components indicated that the 4.02- and 3.18-m-deep pits included snow deposition corresponding to ten years from 2006 to 2016 and seven years from 2009 to 2016, respectively. The mean values for annual snow deposition for the 4.02-m-deep pit were 138 and 145 mm yr? 1 in water equivalent (mm w.e. Yr? 1) in 2006?2016 and 2009?2016, respectively. The average deposition for the 3.18-m-deep pit was 149 mm w.e. Yr? 1 between 2009 and 2016. Seasonal variation in concentrations of major ion species and dust were similar to those previously reported for Greenland. The maximum Cl-/Na+ concentration ratios in the summer were much higher than the ratios at other sites in Greenland.

Temporal variability in surface mass balance (SMB) on the Greenland ice sheet is important for understanding the mass balance of the ice sheet. Additionally, knowledge of the spatial variability in SMB at ice core drilling sites helps to interpret the spatial representativeness of SMB data obtained from a single ice core. In this study, to investigate the spatiotemporal variability in recent SMB in the East Greenland Ice Core Project (EGRIP) area in the northeastern Greenland ice sheet, pit observations were made at six sites in the summers of 2016?2018. In all pits, depth profiles of water isotope ratios showed clear seasonal variations. The annual SMB differed from site to site, which is probably due to post-depositional redistribution of snow caused by wind erosion and snowdrift. However, the multiple-site averages of annual SMBs, which ranged from 134 to 157 mm w. e. yr-1 (average 146 mm w. e. yr? 1) during 2009?2017, were very similar. This indicates that annual SMBs in the EGRIP area were nearly constant in this period. The seasonal SMBs in the EGRIP area tended to be larger in the summer?winter period than in the winter?summer period.

info:eu-repo/semantics/published

Temporal variability in surface mass balance (SMB) on the Greenland ice sheet is important for understanding the mass balance of the ice sheet. Additionally, knowledge of the spatial variability in SMB at ice core drilling sites helps to interpret the spatial representativeness of SMB data obtained from a single ice core. In this study, to investigate the spatiotemporal variability in recent SMB in the East Greenland Ice Core Project (EGRIP) area in the northeastern Greenland ice sheet, pit observations were made at six sites in the summers of 2016?2018. In all pits, depth profiles of water isotope ratios showed clear seasonal variations. The annual SMB differed from site to site, which is probably due to post-depositional redistribution of snow caused by wind erosion and snowdrift. However, the multiple-site averages of annual SMBs, which ranged from 134 to 157 mm w. e. yr-1 (average 146 mm w. e. yr? 1) during 2009?2017, were very similar. This indicates that annual SMBs in the EGRIP area were nearly constant in this period. The seasonal SMBs in the EGRIP area tended to be larger in the summer?winter period than in the winter?summer period.

Climatic variabilities on millennial and longer time scales with a bipolar seesaw pattern have been documented in paleoclimatic records, but their frequencies, relationships with mean climatic state, and mechanisms remain unclear. Understanding the processes and sensitivities that underlie these changes will underpin better understanding of the climate system and projections of its future change. We investigate the long-term characteristics of climatic variability using a new ice-core record from Dome Fuji, East Antarctica, combined with an existing long record from the Dome C ice core. Antarctic warming events over the past 720, 000 years are most frequent when the Antarctic temperature is slightly below average on orbital time scales, equivalent to an intermediate climate during glacial periods, whereas interglacial and fully glaciated climates are unfavourable for a millennial-scale bipolar seesaw. Numerical experiments using a fully coupled atmosphere-ocean general circulation model with freshwater hosing in the northern North Atlantic showed that climate becomes most unstable in intermediate glacial conditions associated with large changes in sea ice and the Atlantic Meridional Overturning Circulation. Model sensitivity experiments suggest that the prerequisite for the most frequent climate instability with bipolar seesaw pattern during the late Pleistocene era is associated with reduced atmospheric CO2 concentration via global cooling and sea ice formation in the North Atlantic, in addition to extended Northern Hemisphere ice sheets.

Climatic variabilities on millennial and longer time scales with a bipolar seesaw pattern have been documented in paleoclimatic records, but their frequencies, relationships with mean climatic state, and mechanisms remain unclear. Understanding the processes and sensitivities that underlie these changes will underpin better understanding of the climate system and projections of its future change. We investigate the long-term characteristics of climatic variability using a new ice-core record from Dome Fuji, East Antarctica, combined with an existing long record from the Dome C ice core. Antarctic warming events over the past 720,000 years are most frequent when the Antarctic temperature is slightly below average on orbital time scales, equivalent to an intermediate climate during glacial periods, whereas interglacial and fully glaciated climates are unfavourable for a millennial-scale bipolar seesaw. Numerical experiments using a fully coupled atmosphere-ocean general circulation model with freshwater hosing in the northern North Atlantic showed that climate becomes most unstable in intermediate glacial conditions associated with large changes in sea ice and the Atlantic Meridional Overturning Circulation. Model sensitivity experiments suggest that the prerequisite for the most frequent climate instabilitywith bipolar seesaw pattern during the late Pleistocene era is associated with reduced atmospheric CO2 concentration via global cooling and sea ice formation in the North Atlantic, in addition to extended Northern Hemisphere ice sheets.

Climatic variabilities on millennial and longer time scales with a bipolar seesaw pattern have been documented in paleoclimatic records, but their frequencies, relationships with mean climatic state, and mechanisms remain unclear. Understanding the processes and sensitivities that underlie these changes will underpin better understanding of the climate system and projections of its future change. We investigate the long-term characteristics of climatic variability using a new ice-core record from Dome Fuji, East Antarctica, combined with an existing long record from the Dome C ice core. Antarctic warming events over the past 720,000 years are most frequent when the Antarctic temperature is slightly below average on orbital time scales, equivalent to an intermediate climate during glacial periods, whereas interglacial and fully glaciated climates are unfavourable for a millennial-scale bipolar seesaw. Numerical experiments using a fully coupled atmosphere-ocean general circulation model with freshwater hosing in the northern North Atlantic showed that climate becomes most unstable in intermediate glacial conditions associated with large changes in sea ice and the Atlantic Meridional Overturning Circulation. Model sensitivity experiments suggest that the prerequisite for the most frequent climate instabilitywith bipolar seesaw pattern during the late Pleistocene era is associated with reduced atmospheric CO2 concentration via global cooling and sea ice formation in the North Atlantic, in addition to extended Northern Hemisphere ice sheets.

Climatic variabilities on millennial and longer time scales with a bipolar seesaw pattern have been documented in paleoclimatic records, but their frequencies, relationships with mean climatic state, and mechanisms remain unclear. Understanding the processes and sensitivities that underlie these changes will underpin better understanding of the climate system and projections of its future change. We investigate the long-term characteristics of climatic variability using a new ice-core record from Dome Fuji, East Antarctica, combined with an existing long record from the Dome C ice core. Antarctic warming events over the past 720,000 years are most frequent when the Antarctic temperature is slightly below average on orbital time scales, equivalent to an intermediate climate during glacial periods, whereas interglacial and fully glaciated climates are unfavourable for a millennial-scale bipolar seesaw. Numerical experiments using a fully coupled atmosphere-ocean general circulation model with freshwater hosing in the northern North Atlantic showed that climate becomes most unstable in intermediate glacial conditions associated with large changes in sea ice and the Atlantic Meridional Overturning Circulation. Model sensitivity experiments suggest that the prerequisite for the most frequent climate instabilitywith bipolar seesaw pattern during the late Pleistocene era is associated with reduced atmospheric CO2 concentration via global cooling and sea ice formation in the North Atlantic, in addition to extended Northern Hemisphere ice sheets.

We have investigated the changes in Cryptomeria japonica pollen concentrations in a melting snow cover at different time points in order to understand the alterations in their concentration peaks. Recent studies have revealed that the pollen concentration peaks in mountain snow covers in temperate regions are useful for distinguishing between annual and several seasonal layers. Moreover, a dating method was applicable to a melting ice core. However, the manner in which pollen grains and their concentration peak values get influenced by melt water needs to be clarified. The present study intends to clarify this issue. Snow samples were collected from the Norikura Highland in central Japan during two snow-melting seasons: (1) from March to April in 2005 and (2) from March to May in 2006. The analysis of the C. japonica pollens was carried out because the pollen release reaches a high level from March to April in Japan when the winter seasonal snow still remains at the site; further, the pollen grains are commonly found within a typical size range. The results showed that the snow depth from the ground surface decreased because of snow melting during April and May, and the pollen concentration peak was consistently observed at the surface of the snow cover during the melting process. This indicated that the pollen concentration peak was not redistributed to the lower layers because of melting and the pollen grains present in the melted snow were concentrated at the surface. However, when the snow cover was about to disappear, the peak value decreased. This might account for the horizontal relocation of the pollen grains at the surface. Additionally, the peaks persisted at the surface even in the regions of the snow cover where water channels were formed. This indicated that the pollen peaks in the snow cover did not move toward the lower layers because of significant melting, although the peak values themselves may be changed due to the horizontal relocation of pollen

Most of the aerosol particles present in the surface snow and ice of inland Antarctica come from primary sea salt (sodium chloride) and marine biological activity (methansulfonic and sulfuric acids). Melted water from surface snow, firn, and Holocene ice contains mainly sodium, chloride, and sulfate ions. Although it is well known that sea salt aerosols react rapidly with sulfuric acid, a process known as sulfatization, it is not known when this process takes place. In this research we undertake to measure the proportion of sea salt aerosols that undergo sulfatization in the atmosphere and surface snow, as opposed to deeper ice, in order to understand the suitability of sea salt aerosols as a proxy for past climates in deep ice cores. We directly measure the sulfatization rates in recently fallen snow (0-4 m in depth) collected at the Dome Fuji station, using X-ray dispersion spectroscopy to determine the constituent elements of soluble particles and computing the molar ratios of sodium chloride and sodium sulfate. We estimate that about 90% of the initial sea salt aerosols sulfatize as they are taken up by precipitation over Dome Fuji or in the snowpack within one year after being deposited on the ice sheet., 10

During the Japanese-Swedish Antarctic traverse expedition of 2007/08, we measured the surface snow density at 46 locations along the 2800 km long route from Syowa station to Wasa station in East Antarctica. The mean snow density for the upper 1 (or 0.5) m layer varied from 333 to 439 kg m(-3) over a region spanning an elevation range of 365-3800 m a.s.l. The density variations were associated with the elevation of the sampling sites; the density decreased as the elevation increased, moving from the coastal region inland. However, the density was relatively insensitive to the change in elevation along the ridge on the Antarctic plateau between Dome F and Kohnen stations. Because surface wind is weak in this region, irrespective of elevation, the wind speed was suggested to play a key role in the near-surface densification. The results of multiple regression performed on the density using meteorological variables were significantly improved by the inclusion of wind speed as a predictor. The regression analysis yielded a linear dependence between the density and the wind speed, with a coefficient of 13.5 kg m(-3) (m s(-1))(-1). This relationship is nearly three times stronger than a value previously computed from a dataset available in Antarctica. Our data indicate that the wind speed is more important to estimates of the surface snow density in Antarctica than has been previously assumed., AuthorCount:7

Most of the aerosol particles present in the surface snow and ice of inland Antarctica come from primary sea salt (sodium chloride) and marine biological activity (methansulfonic and sulfuric acids). Melted water from surface snow, firn, and Holocene ice contains mainly sodium, chloride, and sulfate ions. Although it is well known that sea salt aerosols react rapidly with sulfuric acid, a process known as sulfatization, it is not known when this process takes place. In this research we undertake to measure the proportion of sea salt aerosols that undergo sulfatization in the atmosphere and surface snow, as opposed to deeper ice, in order to understand the suitability of sea salt aerosols as a proxy for past climates in deep ice cores. We directly measure the sulfatization rates in recently fallen snow (0-4 m in depth) collected at the Dome Fuji station, using X-ray dispersion spectroscopy to determine the constituent elements of soluble particles and computing the molar ratios of sodium chloride and sodium sulfate. We estimate that about 90% of the initial sea salt aerosols sulfatize as they are taken up by precipitation over Dome Fuji or in the snowpack within one year after being deposited on the ice sheet.

During the Japanese-Swedish Antarctic traverse expedition of 2007/08, we measured the surface snow density at 46 locations along the 2800 km long route from Syowa station to Wasa station in East Antarctica. The mean snow density for the upper 1 (or 0.5) m layer varied from 333 to 439 kg m^[-3] over a region spanning an elevation range of 365-3800 m a.s.l. The density variations were associated with the elevation of the sampling sites; the density decreased as the elevation increased, moving from the coastal region inland. However, the density was relatively insensitive to the change in elevation along the ridge on the Antarctic plateau between Dome F and Kohnen stations. Because surface wind is weak in this region, irrespective of elevation, the wind speed was suggested to play a key role in the near-surface densification. The results of multiple regression performed on the density using meteorological variables were significantly improved by the inclusion of wind speed as a predictor. The regression analysis yielded a linear dependence between the density and the wind speed, with a coefficient of 13.5 kg m^[-3] (m s^[-1])^[-1]. This relationship is nearly three times stronger than a value previously computed from a dataset available in Antarctica. Our data indicate that the wind speed is more important to estimates of the surface snow density in Antarctica than has been previously assumed.

Most of the aerosol particles present in the surface snow and ice of inland Antarctica come from primary sea salt (sodium chloride) and marine biological activity (methansulfonic and sulfuric acids). Melted water from surface snow, firn, and Holocene ice contains mainly sodium, chloride, and sulfate ions. Although it is well known that sea salt aerosols react rapidly with sulfuric acid, a process known as sulfatization, it is not known when this process takes place. In this research we undertake to measure the proportion of sea salt aerosols that undergo sulfatization in the atmosphere and surface snow, as opposed to deeper ice, in order to understand the suitability of sea salt aerosols as a proxy for past climates in deep ice cores. We directly measure the sulfatization rates in recently fallen snow (0-4 m in depth) collected at the Dome Fuji station, using X-ray dispersion spectroscopy to determine the constituent elements of soluble particles and computing the molar ratios of sodium chloride and sodium sulfate. We estimate that about 90% of the initial sea salt aerosols sulfatize as they are taken up by precipitation over Dome Fuji or in the snowpack within one year after being deposited on the ice sheet.

During the Japanese-Swedish Antarctic traverse expedition of 2007/08, we measured the surface snow density at 46 locations along the 2800 km long route from Syowa station to Wasa station in East Antarctica. The mean snow density for the upper 1 (or 0.5) m layer varied from 333 to 439 kg m^[-3] over a region spanning an elevation range of 365-3800 m a.s.l. The density variations were associated with the elevation of the sampling sites; the density decreased as the elevation increased, moving from the coastal region inland. However, the density was relatively insensitive to the change in elevation along the ridge on the Antarctic plateau between Dome F and Kohnen stations. Because surface wind is weak in this region, irrespective of elevation, the wind speed was suggested to play a key role in the near-surface densification. The results of multiple regression performed on the density using meteorological variables were significantly improved by the inclusion of wind speed as a predictor. The regression analysis yielded a linear dependence between the density and the wind speed, with a coefficient of 13.5 kg m^[-3] (m s^[-1])^[-1]. This relationship is nearly three times stronger than a value previously computed from a dataset available in Antarctica. Our data indicate that the wind speed is more important to estimates of the surface snow density in Antarctica than has been previously assumed.

Most of the aerosol particles present in the surface snow and ice of inland Antarctica come from primary sea salt (sodium chloride) and marine biological activity (methansulfonic and sulfuric acids). Melted water from surface snow, firn, and Holocene ice contains mainly sodium, chloride, and sulfate ions. Although it is well known that sea salt aerosols react rapidly with sulfuric acid, a process known as sulfatization, it is not known when this process takes place. In this research we undertake to measure the proportion of sea salt aerosols that undergo sulfatization in the atmosphere and surface snow, as opposed to deeper ice, in order to understand the suitability of sea salt aerosols as a proxy for past climates in deep ice cores. We directly measure the sulfatization rates in recently fallen snow (0-4 m in depth) collected at the Dome Fuji station, using X-ray dispersion spectroscopy to determine the constituent elements of soluble particles and computing the molar ratios of sodium chloride and sodium sulfate. We estimate that about 90% of the initial sea salt aerosols sulfatize as they are taken up by precipitation over Dome Fuji or in the snowpack within one year after being deposited on the ice sheet.

During the Japanese-Swedish Antarctic traverse expedition of 2007/08, we measured the surface snow density at 46 locations along the 2800 km long route from Syowa station to Wasa station in East Antarctica. The mean snow density for the upper 1 (or 0.5) m layer varied from 333 to 439 kg m^[-3] over a region spanning an elevation range of 365-3800 m a.s.l. The density variations were associated with the elevation of the sampling sites; the density decreased as the elevation increased, moving from the coastal region inland. However, the density was relatively insensitive to the change in elevation along the ridge on the Antarctic plateau between Dome F and Kohnen stations. Because surface wind is weak in this region, irrespective of elevation, the wind speed was suggested to play a key role in the near-surface densification. The results of multiple regression performed on the density using meteorological variables were significantly improved by the inclusion of wind speed as a predictor. The regression analysis yielded a linear dependence between the density and the wind speed, with a coefficient of 13.5 kg m^[-3] (m s^[-1])^[-1]. This relationship is nearly three times stronger than a value previously computed from a dataset available in Antarctica. Our data indicate that the wind speed is more important to estimates of the surface snow density in Antarctica than has been previously assumed.