A5030717599- Atmospheric and Environmental Gas Dynamics
- Cryospheric studies and observations
- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- Arctic and Antarctic ice dynamics
- Ocean Acidification Effects and Responses
- Marine and coastal ecosystems
- Methane Hydrates and Related Phenomena
- Polar Research and Ecology
- Marine Biology and Ecology Research
- Atmospheric aerosols and clouds
- Oceanographic and Atmospheric Processes
- Climate change and permafrost
- Space Exploration and Technology
- Winter Sports Injuries and Performance
- Climate variability and models
- Geology and Paleoclimatology Research
- Marine and fisheries research
- Aerospace Engineering and Energy Systems
- Scientific Research and Discoveries
- Spacecraft and Cryogenic Technologies
- Spaceflight effects on biology
- Transportation Systems and Safety
- Tropical and Extratropical Cyclones Research
- Groundwater and Isotope Geochemistry
National Institute of Polar Research
2011-2022
Hokkaido University
2022
Research Organization of Information and Systems
1996-2010
The Graduate University for Advanced Studies, SOKENDAI
2010
Tohoku University
1991-1996
Observations of aerosol constituents and acidic gases in the Antarctic area were carried out at Syowa (39.58°E, 69.00°S) 1997 1998 Dome Fuji stations (39.62°E, 77.37°S) 1997. Sea‐salt concentrations decreased to background levels summer both (Na + , ≤4 nmol m −3 ) ∼0.44 on average). During winter, blizzard strong wind may cause an increase sea‐salt particles Syowa, whereas long‐range transport from boundary layer midlatitudes coastal regions contribute significantly observed Fuji....
In this study, we present evidence that Antarctic and Arctic sea ice act as sink for atmospheric CO 2 during periods of snowmelt surface flooding. The flux measured directly at the flooded ( F flood ) constituted a net −1.1 ± 0.9 mmol C m −2 d −1 (mean 1 SD), which was an order magnitude higher than snow‐air snow bare ). / ratio decreased with increasing water equivalent superimposed‐ice, suggesting properties superimposed‐ice formation affect flux. ranged from 0.1 to 0.5, illustrating...
Histories of atmospheric N 2 O concentration and its δ 15 18 were reconstructed for the period 1952–2001 on basis analyses firn air collected at North Greenland Ice Core Project (NGRIP), Greenland, Dome Fuji H72, Antarctica. The increased from 290 ppbv in 1952 to 316 2001, which agrees well with results observations polar ice core analyses. showed a secular decrease, respective values being 8.9 21.5‰ 7.0 20.5‰ 2001. Their rates change also varied, about −0.02‰ yr −1 1950s −0.04‰ 1960–2001 N,...
During our aerosol measurement program at Syowa Station, Antarctica, in 2004–2007, some low‐visibility (haze) phenomena were observed during winter–spring under conditions with low winds and without drifting snow fog. “Antarctic haze” phenomena, the number concentration of particles black carbon increased by 1 to 2 orders higher relative background whereas surface O 3 dropped simultaneously, especially after polar sunrise. Chemical analysis showed that major constituents haze sea salt (e.g.,...
Antarctic Bottom Water (AABW) occupies the abyssal layer of world ocean and contributes to global overturning circulation. It originates from dense shelf water, which forms brine rejection during sea ice production. An important region AABW formation has been identified off Cape Darnley polynya. However, it remains unclear why how high production leads formation. Using moored acoustic measurements a satellite microwave algorithm, we reveal that underwater frazil dominates in This prevents...
Stratospheric air samples have been collected once per year since 1985 over Japan using a balloon‐borne cryogenic sampler and then analyzed for their CO 2 concentrations. The measurements showed high values of in the lowest part stratosphere, decrease with height to 20.0–25.0 km, almost constant above this level. From comparison results our aircraft upper troposphere lower it is suggested that vertical profile stratospheric strongly related transport processes are associated tropospheric...
In order to elucidate the seasonal and interannual variations of oceanic CO2 uptake in Greenland Sea Barents Sea, partial pressure surface ocean (pCO2 sea) was measured all seasons between 1992 2001. We derived monthly varying relationships pCO2 sea temperature (SST) combined them with SST data from NCEP/NCAR reanalysis determine air–sea flux these seas. The values were normalized year 1995 by assuming that increased at same growth rate (1.5 μatm yr-1) air air) 1995, annual net fluxes...
This is the first estimation of methane efflux from bubbles in lake ice Antarctica. Bubbles suspended shallow 20 lakes were observed as part operations 45th Japanese Antarctic Research Expedition ice‐free rocky areas along eastern coast Lützow‐Holm Bay (Syowa Oasis) East Antarctica 2004. Anomalous concentrations and anomalous dissolved water frequently found. Methane varied 5 orders magnitude, 1.9 ppmv to 18% vol/vol. A procedure that makes estimations flux possible has been developed, on...
Temporal and latitudinal variations of vertical profiles N 2 O isotopomers were observed in the stratosphere over Japan (39°N, 142°E), Sweden (68°N, 20°E), Antarctica (69°N, 40°E) during period between 1990 2001. Samples collected with a balloon‐borne cryogenic sampler analyzed by mass spectrometry laboratory. Observed enrichment factors for heavier ( 15 14 16 O, 18 O) relative to nearly constant lower (less than ∼22 km) but increased at higher altitudes (∼22–35 while showing seasonal...
Systematic collections of stratospheric air samples have been conducted over Japan since 1985 using a balloon-borne cryogenic sampler. The collection was also carried out twice Scandinavia and once Antarctica. Vertical profiles CO2 concentration thus obtained these locations were quite similar to each other; decreased with increasing altitude in the lower stratosphere reached an almost constant value mid-stratosphere. δ13C CO2observed enriched altitude. A negative correlation between...
Solar radiation measurements were made using sun photometers and pyranometers during 31 May-7 June 1991 at several places in Iran 12 June-17 September a fixed place, Bushehr, Iran. In the first period aerosol optical thickness had values about 0.4 wavelength of 0.5 μm coastal area 0.2 plateau area. The Ångström's exponent, which is slope spectrum, around 1 for large city areas less than inland arid areas. Chemical analyses sampled air indicate an effect fossil fuel burning from local...
Systematic collections of stratospheric air samples have been conducted over Japan since 1985 using a balloon-borne cryogenic sampler. The collection was also carried out twice Scandinavia and once Antarctica. Vertical profiles CO2 concentration thus obtained these locations were quite similar to each other; decreased with increasing altitude in the lower stratosphere reached an almost constant value mid-stratosphere. δ13C CO2observed enriched altitude. A negative correlation between...
Dissolved methane (DM) concentrations were measured in 17 lakes as part of the operations 45th Japanese Antarctic Research Expedition ice‐free rocky areas along eastern coast Lützow‐Holm Bay (Syowa Oasis) East Antarctica summer 2003–2004. DM at surfaces 14 ranged from atmospheric equilibrium concentration (about 4 nmol L −1 for freshwater) to 385 . Relatively low less than 50 observed about 60% lakes. Many (area fraction 85%) supersaturated and are thus sources atmosphere. The exchange...
Sampling of atmospheric aerosol particles was carried out at Syowa station, Antarctica (39.58°E, 69.00°S) in 1998. For a better understanding sea-salt chemistry the coastal Antarctic regions, individual were analysed using scanning electron microscope equipped with energy dispersive X-ray spectrometer (SEM-EDX). Individual particle analysis indicates that more modified fine (0.2–2 µm diameter) through heterogeneous reactions mainly gaseous sulfur species summer and reactive nitrogen oxides...
Abstract The horizontal structure of processes causing increases in ozone the Antarctic polar vortex was examined using data measured 2003 from an ozonesonde observation campaign at Syowa Station (39.6°E, 69.0°S) and Improved Limb Atmospheric Spectrometer II (ILAS-II) onboard Advanced Earth Observing Satellite II. ILAS-II are daily distributed uniformly 14 points zonal direction, mostly latitudes. hole that developed one largest recorded. period focus this study is 26 September through 24...
The Southern Ocean is a vast net sink for atmospheric carbon dioxide (CO2), with marine phytoplankton playing crucial role in CO2 fixation. We assessed how changes the dominant community and primary productivity (NPP) affected variations partial pressure of surface water (pCO2sw) Indian sector during austral summer. pCO2sw was negatively correlated total diatom abundances, as estimated from pigment signatures, zone south Antarctic Circumpolar Current; however, not haptophyte abundance....
Precise and continuous measurements of the atmospheric CO2 concentration have been made at Syowa Station, Antarctica since February 1984. The diurnal variation was hardly observable throughout year. secular trend variable with time, showing slow increase in 1984, 1986 1988 rapid 1985 1987. annual especially large 1987, which may be related to 1986/1987 ENSO event. average rate over last 5 years about 1.6 ppmv yr-1. seasonal cycle showed minimum maximum concentrations mid-April early October,...
Abstract. Partial pressure of CO2 (pCO2) in surface water and vertical profiles the carbonate system parameters were measured during austral summer Indian sector Southern Ocean (64–67° S, 32–58° E) January 2006 to understand dynamics seawater seasonal ice zone. Surface-water pCO2 ranged from 275 400 μatm, longitudinal variations reflected dominant influence temperature dilution by sea meltwater between 32 40° E biological productivity 40 58° E. Using data minimum layer (−1.9 °C < T −1.5...
Abstract To determine annual layers for reconstructing the past environment at resolution from ice cores, we employed snow-stake data back to 1972, tritium content, solid electrical conductivity measurements (ECM) and stratigraphic properties 73m core H72 site, east Dronning Maud Land, Antarctica. average surface mass balance is 307 mma –1 w.e. during last 27 years continuous accumulation data, 317 according densification model 311 167 based on annual-layer counting. ECM age closely...