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Gravitational separation suggested by O 2 /N 2 , δ 15 N of N 2 , δ 18 O of O 2 , Ar/N 2 observed in the lowermost part of the stratosphere at northern middle and high latitudes in the early spring of 2002
Author(s) -
Ishidoya Shigeyuki,
Morimoto Shinji,
Sugawara Satoshi,
Watai Tomonori,
Machida Toshinobu,
Aoki Shuji,
Nakazawa Takakiyo,
Yamanouchi Takashi
Publication year - 2008
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2007gl031526
Subject(s) - stratosphere , troposphere , atmospheric sciences , arctic , latitude , physics , geology , geodesy , oceanography
Lower stratospheric O 2 /N 2 ratios ( δ (O 2 /N 2 )) at northern middle and high latitudes were measured by analyzing aircraft air samples collected between Nagoya, Japan and Svalbard Islands in the Arctic during the early spring of 2002. The measured values of δ (O 2 /N 2 ) are relatively uniform horizontally in the lowermost part of the stratosphere but increase with height. Vertical distributions of δ (O 2 /N 2 ) and the CO 2 concentration observed over Svalbard Islands and Barrow, Alaska are negatively correlated. By examining the rates of change in δ (O 2 /N 2 ) and δ 13 C of CO 2 relative to the CO 2 concentration, such a correlation observed is mainly attributable to upward propagation of their seasonal cycles produced on the ground surface for the troposphere and height‐dependent air age for the stratosphere. However, from the vertical profiles of δ 15 N of N 2 , δ 18 O of O 2 and δ (Ar/N 2 ) measured in the lowermost part of the stratosphere over Svalbard Islands, it is suggested that the relationship between δ (O 2 /N 2 ) and the CO 2 concentration is affected by the gravitational separation. By correcting the measured δ (O 2 /N 2 ) and δ 13 C values for this gravitational separation, the relationships of δ (O 2 /N 2 ) and δ 13 C with the CO 2 concentration are consistent with those expected from their secular trends in the troposphere.