Masao Uchida
Datos Biográficos
| ID | 5597070 |
|---|---|
| NOMBRE | Masao Uchida |
| NOMBRES | Masao |
| APELLIDO | Uchida |
| FIRMA | UCHIDA M |
| AFILIACIONES | National Institute for Environmental Studies |
| ORCID | 0000-0002-3496-2772 |
| VERIFICADO | Sí |
| TOTAL DE OBRAS | 23 |
| TOTAL DE CITAS | 61 |
| TOTAL COMO AUTOR | 23 |
| TOTAL COMO EDITOR | 0 |
| PRIMER AÑO DE PUBLICACIÓN | 2001 |
| AÑO MÁS RECIENTE DE PUBLICACIÓN | 2024 |
| ÍNDICE H | 5 |
Source Apportionment of Atmospheric and Sedimentary Pahs From Kolkata, India Using Compound-Class-Specific Radiocarbon Analysis (Ccsra)
Polycyclic aromatic hydrocarbons (PAHs) are major air pollutants that are ubiquitously produced by the combustion of organic materials, and it is extremely important to identify their pollution sources. In this study, molecular fingerprinting and compound class-specific radiocarbon dating (CCSRA) were performed on PAHs from canal sediments and air samples collected in Kolkata, India’s third largest city (population approximately 16 million), wher…
Characterization of Fine Carbonaceous Aerosols From the Eastern Mediterranean
In order to better characterise carbonaceous components in atmospheric aerosols and to assess the contributions of fossil carbon (FC) and non-fossil carbon (NFC) sources and their seasonality in the Eastern Mediterranean, we collected fine (PM 1.3 ) aerosols at a remote marine background site, the Finokalia Research Station, Crete, Greece, over a period of one-year. PM 1.3 samples were analysed for elemental carbon (EC), organic carbon (OC), wate…
Radiocarbon Ages of Plant Remains in Massive Ground Ice and Underlying Sediments of the Barrow Permafrost Tunnel, Alaska
Massive ground ice found in the Barrow Permafrost Tunnel at 3–7 m depths from the surface has been interpreted as an ice wedge and used to reconstruct early Holocene environmental changes. To better understand the development of this ground ice, we conducted radiocarbon dating for 34 samples of plant remains from the massive ground ice and underlying sediment layer. A significantly large gap in the measured radiocarbon ages (more than 24 ka) betw…
Paleoenvironments and relative sea-level changes caused by regional tectonics during the last 4500 years in Kumihama Bay, northern Kyoto Prefecture, central Japan
Difference in timing of maximum flooding in two adjacent lowlands in the Tokyo area caused by the difference in sediment supply rate
Variation in subsurface water temperature and its link to the Kuroshio Current in the Okinawa Trough during the last 38.5 kyr
Compatibility of Atmospheric 14 CO 2 Measurements
Combining atmospheric Δ 14 CO 2 data sets from different networks or laboratories requires secure knowledge on their compatibility. In the present study, we compare Δ 14 CO 2 results from the Heidelberg low-level counting (LLC) laboratory to 12 international accelerator mass spectrometry (AMS) laboratories using distributed aliquots of five pure CO 2 samples. The averaged result of the LLC laboratory has a measurement bias of –0.3±0.5‰ with respe…
Variation of Δ 14 C and δ 13 C Values of Dissolved Humic and Fulvic Acids in the Tokachi River System in Northern Japan
Characteristics of dissolved humic and fulvic acids in river waters were studied during 2003–2005 at 4 sites located in the headwaters and in the upper and lower Tokachi River, including a lowland tributary site. Fulvic acids from the headwaters to downstream areas have similar elemental composition and 13 C-NMR spectra. Humic acids have similar characteristics in the Tokachi River system. In contrast, δ 13 C and Δ 14 C values exhibit a decreasin…
Initial Results of an Intercomparison of AMS-Based Atmospheric 14 CO 2 Measurements
This article presents results from the first 3 rounds of an international intercomparison of measurements of Δ 14 CO 2 in liter-scale samples of whole air by groups using accelerator mass spectrometry (AMS). The ultimate goal of the intercomparison is to allow the merging of Δ 14 CO 2 data from different groups, with the confidence that differences in the data are geophysical gradients and not artifacts of calibration. Eight groups have participa…
Multibeam bathymetric and sediment profiler evidences for ice grounding and crater on the Chukchi and Beaufort borderland, Arctic Ocean
Effects of Vegetation Switch and Subsequent Change in Soil Invertebrate Composition on Soil Carbon Accumulation Patterns, Revealed by Radiocarbon Concentrations
Vegetation types strongly affect soil organic carbon (SOC) accumulation in the terrestrial ecosystem through multiple factors such as litter quality and soil biodiversity. However, the roles of soil fauna in SOC accumulation remain unclear. The objectives of this study were to (1) examine how changes in litter types and soil animal communities affect SOC accumulation in continuously forested or vegetation-switched forest areas; and (2) discuss th…
Spatial Distribution of Δ 14 C Values of Organic Matter in Surface Sediments Off Saru River in Northern Japan, One Year After a Flood Event in 2006
Dispersion and deposition of terrestrial organic matter by flooding on the inner shelf were studied using C/N ratios, δ 13 C, and Δ 14 C values of sedimentary organic matter. Surface sediment samples (top 2 cm) were collected from coastal areas near the Saru River in southwestern Hokkaido, northern Japan, 1 yr after a flood event in 2006. Riverine suspended solids were also collected at a fixed station downstream during 2006–2008. Sandy sediments…
The Effects of Rainfall on Carbon Isotopes of POC in the Teshio River, Northern Japan
During a rainfall event in early September 2006, the transport behavior of particulate organic carbon (POC) in a small river (Teshio River, northern Japan) with alluvial plain and forest characteristics was investigated chiefly with carbon isotopes. The radiocarbon (Δ 14 C value) of POC varied widely from –56%‰ at the beginning of the rain event to –10%‰ at peak rainfall. The Δ 14 C values have a positive correlation with C/N ratios and a negativ…
High Contribution of Recalcitrant Organic Matter to DOC in a Japanese Oligotrophic Lake Revealed by 14 C Measurements
Carbon isotopes ( 14 C and 13 C) of dissolved organic carbon (DOC) in a Japanese oligotrophic lake (Lake Towada) were measured to study the origin and cycling of dissolved organic matter (DOM) in Lake Towada. Lake water samples were collected at 3 depths (0, 30, and 80 or 85 m) during 4 months (April, June, August, and October) in 2006. 14 C measurements of DOC were performed by accelerator mass spectrometry (AMS) at the National Institute for En…
Ecological variations in diatom assemblages in the Paleo-Kathmandu Lake linked with global and Indian monsoon climate changes for the last 600,000 years
Variations in fossil diatom assemblages and their relationship with global and Indian monsoon climate changes for the last 600,000 yr were investigated using a core of ancient lake (Paleo-Kathmandu Lake) sediments drilled at the Kathmandu Basin, Nepal Himalaya. Chronological scales of the core were constructed by tuning pollen wet and dry index records to the SPECMAP δ 18 O stack record. Examinations of biogenic silica contents and fossil diatom …
Lateral extension in Sphagnum mires along the southern margin of the boreal region, Western Siberia
Although recent studies have recognized Northern Eurasian ecosystems as an important carbon reservoir, little is known about the forest–peatland interactions in a boreal environment induced by ongoing climatic changes. This study focuses on the evaluation of both the long-term and contemporary trends of land-cover changes and rates of lateral extension of peat-accumulating wetlands toward the adjacent forests, estimated at the southern climatic r…
Sphagnum peatland development at their southern climatic range in West Siberia
A region of western Siberia is vulnerable to the predicted climatic change which may induce an important modification to the carbon balance in wetland ecosystems. This study focuses on the evaluation of both the long-term and contemporary trends of peat (carbon) accumulation and its patterns at the southern climatic range of Sphagnum peatlands in western Siberia. Visible and physical features of peat and detailed reconstructions of successional c…
Radiocarbon Marine Reservoir Ages in the Northwestern Pacific Off Hokkaido Island, Japan, During the Last Deglacial Period
We measured radiocarbon ages of planktic foraminifera in 4 sediment cores from the northwestern Pacific region off northern Japan in order to estimate marine reservoir ages during the B⊘lling-Aller⊘d period. The ages of deglacial tephra markers from 2 Japanese source volcanoes identified in these sediment cores had been previously estimated from 14 C ages of terrestrial charcoal and buried forests. By comparing the foraminiferal and tephra ages, …
Correlation between Indian Ocean summer monsoon and North Atlantic climate during the Holocene
Radiocarbon Marine Reservoir Effect in Human Remains from the Kitakogane Site, Hokkaido, Japan
Radiocarbon and Stable Isotope Analyses on the Earliest Jomon Skeletons from the Tochibara Rockshelter, Nagano, Japan
This study presents the results of carbon and nitrogen isotopic analyses of six human skeletons excavated from the Tochibara rockshelter (Nagano, Japan). The human skeletons were reported to be accompanied by “Oshigata-mon” type pottery dating to the Earliest Jomon period (8900 BP ≃ 6600 BP). A radiocarbon determination from charcoal associated with the human remains was reported to be 8650 ± 180 BP (GaK-1056). However, the depositional context o…
Compound-Specific Radiocarbon Ages of Fatty Acids in Marine Sediments from the Western North Pacific
Compound-specific radiocarbon analysis of five fatty-acid biomarkers was conducted for marine sediments collected from the western North Pacific. The fatty acids (C 12 to C 34 ) showed a typical bimodal distribution pattern with two maxima at C 16 and C 26 . Their carbon isotopic compositions ranged from −25.1‰ (C 16 ) to −31.8‰ (C 28 ), suggesting that they derived from terrestrial higher plants and marine organisms. A large variations of 14 C a…
Marine Radiocarbon Reservoir Effect in the Western North Pacific Observed in Archaeological Fauna
Faunal remains originating from terrestrial and marine mammals, and belonging to the same archaeological deposits were compared to evaluate the marine radiocarbon reservoir ages around the Hokkaido island, Japan. From five shell middens of different ages from the Jomon period (4900 BP) to the Ainu cultural period (800 BP), 107 animal bone samples were selected for radiocarbon measurements. The apparent age differences between Japanese deer and no…
Radiocarbon Marine Reservoir Effect in Human Remains from the Kitakogane Site, Hokkaido, Japan
Marine Radiocarbon Reservoir Effect in the Western North Pacific Observed in Archaeological Fauna
Faunal remains originating from terrestrial and marine mammals, and belonging to the same archaeological deposits were compared to evaluate the marine radiocarbon reservoir ages around the Hokkaido island, Japan. From five shell middens of different ages from the Jomon period (4900 BP) to the Ainu cultural period (800 BP), 107 animal bone samples were selected for radiocarbon measurements. The apparent age differences between Japanese deer and no…
Radiocarbon and Stable Isotope Analyses on the Earliest Jomon Skeletons from the Tochibara Rockshelter, Nagano, Japan
This study presents the results of carbon and nitrogen isotopic analyses of six human skeletons excavated from the Tochibara rockshelter (Nagano, Japan). The human skeletons were reported to be accompanied by “Oshigata-mon” type pottery dating to the Earliest Jomon period (8900 BP ≃ 6600 BP). A radiocarbon determination from charcoal associated with the human remains was reported to be 8650 ± 180 BP (GaK-1056). However, the depositional context o…
Initial Results of an Intercomparison of AMS-Based Atmospheric 14 CO 2 Measurements
This article presents results from the first 3 rounds of an international intercomparison of measurements of Δ 14 CO 2 in liter-scale samples of whole air by groups using accelerator mass spectrometry (AMS). The ultimate goal of the intercomparison is to allow the merging of Δ 14 CO 2 data from different groups, with the confidence that differences in the data are geophysical gradients and not artifacts of calibration. Eight groups have participa…
Compound-Specific Radiocarbon Ages of Fatty Acids in Marine Sediments from the Western North Pacific
Compound-specific radiocarbon analysis of five fatty-acid biomarkers was conducted for marine sediments collected from the western North Pacific. The fatty acids (C 12 to C 34 ) showed a typical bimodal distribution pattern with two maxima at C 16 and C 26 . Their carbon isotopic compositions ranged from −25.1‰ (C 16 ) to −31.8‰ (C 28 ), suggesting that they derived from terrestrial higher plants and marine organisms. A large variations of 14 C a…
Compatibility of Atmospheric 14 CO 2 Measurements
Combining atmospheric Δ 14 CO 2 data sets from different networks or laboratories requires secure knowledge on their compatibility. In the present study, we compare Δ 14 CO 2 results from the Heidelberg low-level counting (LLC) laboratory to 12 international accelerator mass spectrometry (AMS) laboratories using distributed aliquots of five pure CO 2 samples. The averaged result of the LLC laboratory has a measurement bias of –0.3±0.5‰ with respe…
High Contribution of Recalcitrant Organic Matter to DOC in a Japanese Oligotrophic Lake Revealed by 14 C Measurements
Carbon isotopes ( 14 C and 13 C) of dissolved organic carbon (DOC) in a Japanese oligotrophic lake (Lake Towada) were measured to study the origin and cycling of dissolved organic matter (DOM) in Lake Towada. Lake water samples were collected at 3 depths (0, 30, and 80 or 85 m) during 4 months (April, June, August, and October) in 2006. 14 C measurements of DOC were performed by accelerator mass spectrometry (AMS) at the National Institute for En…
Compound-Specific Radiocarbon Ages of Fatty Acids in Marine Sediments from the Western North Pacific
Compound-specific radiocarbon analysis of five fatty-acid biomarkers was conducted for marine sediments collected from the western North Pacific. The fatty acids (C 12 to C 34 ) showed a typical bimodal distribution pattern with two maxima at C 16 and C 26 . Their carbon isotopic compositions ranged from −25.1‰ (C 16 ) to −31.8‰ (C 28 ), suggesting that they derived from terrestrial higher plants and marine organisms. A large variations of 14 C a…
Marine Radiocarbon Reservoir Effect in the Western North Pacific Observed in Archaeological Fauna
Faunal remains originating from terrestrial and marine mammals, and belonging to the same archaeological deposits were compared to evaluate the marine radiocarbon reservoir ages around the Hokkaido island, Japan. From five shell middens of different ages from the Jomon period (4900 BP) to the Ainu cultural period (800 BP), 107 animal bone samples were selected for radiocarbon measurements. The apparent age differences between Japanese deer and no…
Radiocarbon Marine Reservoir Effect in Human Remains from the Kitakogane Site, Hokkaido, Japan
Radiocarbon and Stable Isotope Analyses on the Earliest Jomon Skeletons from the Tochibara Rockshelter, Nagano, Japan
This study presents the results of carbon and nitrogen isotopic analyses of six human skeletons excavated from the Tochibara rockshelter (Nagano, Japan). The human skeletons were reported to be accompanied by “Oshigata-mon” type pottery dating to the Earliest Jomon period (8900 BP ≃ 6600 BP). A radiocarbon determination from charcoal associated with the human remains was reported to be 8650 ± 180 BP (GaK-1056). However, the depositional context o…
Correlation between Indian Ocean summer monsoon and North Atlantic climate during the Holocene
Sphagnum peatland development at their southern climatic range in West Siberia
A region of western Siberia is vulnerable to the predicted climatic change which may induce an important modification to the carbon balance in wetland ecosystems. This study focuses on the evaluation of both the long-term and contemporary trends of peat (carbon) accumulation and its patterns at the southern climatic range of Sphagnum peatlands in western Siberia. Visible and physical features of peat and detailed reconstructions of successional c…
Radiocarbon Marine Reservoir Ages in the Northwestern Pacific Off Hokkaido Island, Japan, During the Last Deglacial Period
We measured radiocarbon ages of planktic foraminifera in 4 sediment cores from the northwestern Pacific region off northern Japan in order to estimate marine reservoir ages during the B⊘lling-Aller⊘d period. The ages of deglacial tephra markers from 2 Japanese source volcanoes identified in these sediment cores had been previously estimated from 14 C ages of terrestrial charcoal and buried forests. By comparing the foraminiferal and tephra ages, …
Ecological variations in diatom assemblages in the Paleo-Kathmandu Lake linked with global and Indian monsoon climate changes for the last 600,000 years
Variations in fossil diatom assemblages and their relationship with global and Indian monsoon climate changes for the last 600,000 yr were investigated using a core of ancient lake (Paleo-Kathmandu Lake) sediments drilled at the Kathmandu Basin, Nepal Himalaya. Chronological scales of the core were constructed by tuning pollen wet and dry index records to the SPECMAP δ 18 O stack record. Examinations of biogenic silica contents and fossil diatom …
Lateral extension in Sphagnum mires along the southern margin of the boreal region, Western Siberia
Although recent studies have recognized Northern Eurasian ecosystems as an important carbon reservoir, little is known about the forest–peatland interactions in a boreal environment induced by ongoing climatic changes. This study focuses on the evaluation of both the long-term and contemporary trends of land-cover changes and rates of lateral extension of peat-accumulating wetlands toward the adjacent forests, estimated at the southern climatic r…
Effects of Vegetation Switch and Subsequent Change in Soil Invertebrate Composition on Soil Carbon Accumulation Patterns, Revealed by Radiocarbon Concentrations
Vegetation types strongly affect soil organic carbon (SOC) accumulation in the terrestrial ecosystem through multiple factors such as litter quality and soil biodiversity. However, the roles of soil fauna in SOC accumulation remain unclear. The objectives of this study were to (1) examine how changes in litter types and soil animal communities affect SOC accumulation in continuously forested or vegetation-switched forest areas; and (2) discuss th…
Spatial Distribution of Δ 14 C Values of Organic Matter in Surface Sediments Off Saru River in Northern Japan, One Year After a Flood Event in 2006
Dispersion and deposition of terrestrial organic matter by flooding on the inner shelf were studied using C/N ratios, δ 13 C, and Δ 14 C values of sedimentary organic matter. Surface sediment samples (top 2 cm) were collected from coastal areas near the Saru River in southwestern Hokkaido, northern Japan, 1 yr after a flood event in 2006. Riverine suspended solids were also collected at a fixed station downstream during 2006–2008. Sandy sediments…
The Effects of Rainfall on Carbon Isotopes of POC in the Teshio River, Northern Japan
During a rainfall event in early September 2006, the transport behavior of particulate organic carbon (POC) in a small river (Teshio River, northern Japan) with alluvial plain and forest characteristics was investigated chiefly with carbon isotopes. The radiocarbon (Δ 14 C value) of POC varied widely from –56%‰ at the beginning of the rain event to –10%‰ at peak rainfall. The Δ 14 C values have a positive correlation with C/N ratios and a negativ…
High Contribution of Recalcitrant Organic Matter to DOC in a Japanese Oligotrophic Lake Revealed by 14 C Measurements
Carbon isotopes ( 14 C and 13 C) of dissolved organic carbon (DOC) in a Japanese oligotrophic lake (Lake Towada) were measured to study the origin and cycling of dissolved organic matter (DOM) in Lake Towada. Lake water samples were collected at 3 depths (0, 30, and 80 or 85 m) during 4 months (April, June, August, and October) in 2006. 14 C measurements of DOC were performed by accelerator mass spectrometry (AMS) at the National Institute for En…
Multibeam bathymetric and sediment profiler evidences for ice grounding and crater on the Chukchi and Beaufort borderland, Arctic Ocean
Variation of Δ 14 C and δ 13 C Values of Dissolved Humic and Fulvic Acids in the Tokachi River System in Northern Japan
Characteristics of dissolved humic and fulvic acids in river waters were studied during 2003–2005 at 4 sites located in the headwaters and in the upper and lower Tokachi River, including a lowland tributary site. Fulvic acids from the headwaters to downstream areas have similar elemental composition and 13 C-NMR spectra. Humic acids have similar characteristics in the Tokachi River system. In contrast, δ 13 C and Δ 14 C values exhibit a decreasin…
Initial Results of an Intercomparison of AMS-Based Atmospheric 14 CO 2 Measurements
This article presents results from the first 3 rounds of an international intercomparison of measurements of Δ 14 CO 2 in liter-scale samples of whole air by groups using accelerator mass spectrometry (AMS). The ultimate goal of the intercomparison is to allow the merging of Δ 14 CO 2 data from different groups, with the confidence that differences in the data are geophysical gradients and not artifacts of calibration. Eight groups have participa…
Difference in timing of maximum flooding in two adjacent lowlands in the Tokyo area caused by the difference in sediment supply rate
Variation in subsurface water temperature and its link to the Kuroshio Current in the Okinawa Trough during the last 38.5 kyr
Compatibility of Atmospheric 14 CO 2 Measurements
Combining atmospheric Δ 14 CO 2 data sets from different networks or laboratories requires secure knowledge on their compatibility. In the present study, we compare Δ 14 CO 2 results from the Heidelberg low-level counting (LLC) laboratory to 12 international accelerator mass spectrometry (AMS) laboratories using distributed aliquots of five pure CO 2 samples. The averaged result of the LLC laboratory has a measurement bias of –0.3±0.5‰ with respe…
Paleoenvironments and relative sea-level changes caused by regional tectonics during the last 4500 years in Kumihama Bay, northern Kyoto Prefecture, central Japan
Source Apportionment of Atmospheric and Sedimentary Pahs From Kolkata, India Using Compound-Class-Specific Radiocarbon Analysis (Ccsra)
Polycyclic aromatic hydrocarbons (PAHs) are major air pollutants that are ubiquitously produced by the combustion of organic materials, and it is extremely important to identify their pollution sources. In this study, molecular fingerprinting and compound class-specific radiocarbon dating (CCSRA) were performed on PAHs from canal sediments and air samples collected in Kolkata, India’s third largest city (population approximately 16 million), wher…
Characterization of Fine Carbonaceous Aerosols From the Eastern Mediterranean
In order to better characterise carbonaceous components in atmospheric aerosols and to assess the contributions of fossil carbon (FC) and non-fossil carbon (NFC) sources and their seasonality in the Eastern Mediterranean, we collected fine (PM 1.3 ) aerosols at a remote marine background site, the Finokalia Research Station, Crete, Greece, over a period of one-year. PM 1.3 samples were analysed for elemental carbon (EC), organic carbon (OC), wate…
Radiocarbon Ages of Plant Remains in Massive Ground Ice and Underlying Sediments of the Barrow Permafrost Tunnel, Alaska
Massive ground ice found in the Barrow Permafrost Tunnel at 3–7 m depths from the surface has been interpreted as an ice wedge and used to reconstruct early Holocene environmental changes. To better understand the development of this ground ice, we conducted radiocarbon dating for 34 samples of plant remains from the massive ground ice and underlying sediment layer. A significantly large gap in the measured radiocarbon ages (more than 24 ka) betw…
Geology (20 obras) · Geology and Paleoclimatology Research (13 obras) · Geography (12 obras) · Radiocarbon dating (11 obras) · Chemistry (10 obras) · Environmental Science (10 obras) · Isotope Analysis in Ecology (10 obras) · Oceanography (9 obras) · Environmental Chemistry (8 obras) · Paleontology (8 obras)