scholarly journals Temporal variations of the CO2 concentration and its carbon and oxygen isotopic ratios in a temperate forest in the central part of the main island of Japan

Tellus B ◽  
1997 ◽  
Vol 49 (4) ◽  
pp. 364-381 ◽  
Author(s):  
Takakiyo Nakazawa ◽  
Shohei Murayama ◽  
Mitsuko Toi ◽  
Misa Ishizawa ◽  
Kaori Otonashi ◽  
...  
Keyword(s):  
Temperate Forest ◽  
Co2 Concentration ◽  
Temporal Variations ◽  
Isotopic Ratios ◽  
Main Island ◽  
Oxygen Isotopic

Temporal variations of the CO2 concentration and its carbon and oxygen isotopic ratios in a temperate forest in the central part of the main island of Japan

Tellus B ◽  
1997 ◽  
Vol 49 (4) ◽  
pp. 364-381 ◽  
Author(s):  
TAKAKIYO NAKAZAWA ◽  
SHOHEI MURAYAMA ◽  
MITSUKO TOI ◽  
MISA ISHIZAWA ◽  
KAORI OTONASHI ◽  
...  
Keyword(s):  
Temperate Forest ◽  
Co2 Concentration ◽  
Temporal Variations ◽  
Isotopic Ratios ◽  
Main Island ◽  
Oxygen Isotopic

Histoire holocène du climat et de la végétation à Lanoraie (Québec)

1982 ◽  
Vol 19 (10) ◽  
pp. 1938-1952 ◽  
Author(s):  
Paul Comtois
Keyword(s):  
Temperate Forest ◽  
Sugar Maple ◽  
Vegetation History ◽  
Isotopic Ratio ◽  
Isotopic Ratios ◽  
Climatic Variations ◽  
Pioneer Tree ◽  
History Of ◽  
Oxygen Isotopic ◽  
Climatic Cooling

Four different cores were recovered from the same peat complex at Lanoraie (Québec), and have been used to evaluate, by pollen analysis, possible differences in the representation of the vegetation history. The isotopic ratio of oxygen has been used to indicate climatic variations involved in these processes.This method was first tested and calibrated with modern moss samples. A transect of 15 samples, from the temperate forest to the tundra, indicates that annual mean temperatures and evapotranspiration rates have a predominant influence on oxygen isotopic ratios. A sequence of fossil sediments, interpreted in terms of these results, shows a climatic maximum at 3500 BP and a reduction of temperature since 1500 BP in the Lanoraie region.The history of the regional vegetation shows the following succession of stages: (1) establishment of pioneer tree vegetation of pine, oak, elm, and walnut; (2) buildup of a sugar maple forest, contemporaneous with the migration of beech and correlated with a maximum pollen influx and a climatic optimum at about 3500 BP; (3) increase of the representation of spruce and fir after 1500 BP, related to a climatic cooling. Paleobotanical data–the recurrence of ruderal spectra and the presence of Iva xanthifolia– suggest the occurrence of two prehistoric anthropic periods, one before 3500 BP and the other at ca. 1500 BP.

Changes of Ionic and Oxygen Isotopic Composition of the Snowpack at the Glacier Austre Okstindbreen, Norway, 1995

1998 ◽  
Vol 29 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Peter Raben ◽  
Wilfred H. Theakstone
Keyword(s):  
Isotopic Composition ◽  
Sea Level ◽  
Oxygen Isotopes ◽  
Oxygen Isotopic Composition ◽  
Isotopic Ratios ◽  
Vertical Variations ◽  
Oxygen Isotopic ◽  
The Difference ◽  
Liquid Precipitation ◽  
Different Altitudes

Marked vertical variations of ions and oxygen isotopes were present in the snowpack at the glacier Austre Okstindbreen during the pre-melting phase in 1995 at sites between 825 m and 1,470 m above sea level. As the first meltwater percolated from the top of the pack, ions were moved to a greater depth, but the isotopic composition remained relatively unchanged. Ions continued to move downwards through the pack during the melting phase, even when there was little surface melting and no addition of liquid precipitation. The at-a-depth correlation between ionic concentrations and isotopic ratios, strong in the pre-melting phase, weakened during melting. In August, concentrations of Na+ and Mg2+ ions in the residual pack were low and vertical variations were slight; 18O enrichment had occurred. The difference of the time at which melting of the snowpack starts at different altitudes influences the input of ions and isotopes to the underlying glacier.

scholarly journals OXYGEN ISOTOPIC RATIOS IN COOL R CORONAE BOREALIS STARS

2010 ◽  
Vol 714 (1) ◽  
pp. 144-154 ◽  
Author(s):  
D. A. García-Hernández ◽  
David L. Lambert ◽  
N. Kameswara Rao ◽  
Ken H. Hinkle ◽  
Kjell Eriksson
Keyword(s):  
Isotopic Ratios ◽  
Oxygen Isotopic ◽  
R Coronae Borealis Stars

scholarly journals Oxygen isotopic ratios in intermediate-mass red giants

2015 ◽  
Vol 578 ◽  
pp. A33 ◽  
Author(s):  
T. Lebzelter ◽  
O. Straniero ◽  
K. H. Hinkle ◽  
W. Nowotny ◽  
B. Aringer
Keyword(s):  
Isotopic Ratios ◽  
Red Giants ◽  
Intermediate Mass ◽  
Oxygen Isotopic

scholarly journals Temporal variations in atmospheric CO<sub>2</sub> on Rishiri Island in 2006–2013: responses of the interannual variation in amplitude to climate and the terrestrial sink in East Asia

2014 ◽  
Vol 5 (1) ◽  
pp. 809-848
Author(s):  
C. Zhu ◽  
H. Yoshikawa-Inoue
Keyword(s):  
East Asia ◽  
Interannual Variation ◽  
Climatic Factors ◽  
Ecosystem Respiration ◽  
Anthropogenic Activities ◽  
Time Lag ◽  
Co2 Concentration ◽  
Temporal Variations ◽  
Atmospheric Co2 ◽  
Growing Season Length

Abstract. Surface observation of the atmospheric CO2 mixing ratio implies the combined influences of both natural fluctuations and anthropogenic activities on the carbon cycle. Atmospheric CO2 has been measured on Rishiri Island in the outflow region of Eurasia since May 2006. We report the first 7 year temporal atmospheric CO2 variations from diurnal to interannual scales. In the diurnal scale, an obvious cycle appeared as a minimum in the afternoon and maximum at midnight in the summer months. Seasonally, the maximum CO2 concentration appeared around the beginning of April, while the minimum appeared around the middle of August. A mean growing season length of ~126 days was estimated. In the period from 2007 to 2012, the peak-to-peak amplitude increased until 2009 and decreased thereafter, with a mean value of 19.7 ppm. In the long term, atmospheric CO2 is increasing by a mean growth rate of 2.1 ppm year−1. Investigations on the driving climatic factors on the interannual variation in amplitude indicated that temperature in East Asia (40–60° N, 90–150° E) affected the CO2 amplitude by affecting the seasonal maximum, with a time lag of 1–2 years. On the contrary, precipitation did not likely affect CO2 amplitudes. The amplitude also responded to a natural carbon source/sink variation in East Asia. We suggest that temperature in the first year would affect carbon sinks in the second year in the fetch regions, which further affect CO2 amplitude mainly through ecosystem respiration. Circulation changes also likely contributed to the decreasing amplitude since 2009, as indicated by the simultaneous decrease in the 222Rn concentration in spring and summer.

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