5:15 PM - 6:45 PM
[ACC27-P04] A 20-year record of 17O-excess in a Greenland ice core and its variation mechanism
Keywords:17O-excess, ice core
The 17O-excess of water vapor varies due to kinetic isotopic effects during evaporation and reflects relative humidity (Barkan & Luz, RCM, 2007: Uemura et al., GRL, 2010). Therefore, it was expected that the relative humidity of the sea area where the water vapor originated could be inferred from the 17O-excess of precipitation. However, subsequent precipitation observations have shown that the 17O-excess also varies during the advection of air masses from the water vapor source and during precipitation, or snow formation. These observations of 17O-excess in precipitation from various regions have been limited to short-term data of 1-2 years, and data for the Arctic region are sparse. In this study, in order to understand the mechanism of 17O-excess variability in polar precipitation, we analyze a Greenland ice core to obtain 17O-excess data that can be compared with long-term meteorological observations and.
The SE-Dome II (SE2) ice core (Iizuka et al., BGR, 2021) drilled in the high accumulation area in south-eastern Greenland were used for isotopic analysis. We measured for ca. 20 year-long record using a cavity ring-down spectrometer. Climatic values of 17O-excess in the SE2 ice core showed a maximum in January-March and a minimum in June-July. The timing and values of the maxima and minima of the SE2 record are well consistent with the 3-year data (2003-2005) from the NEEM ice core in northwest Greenland (Landais etal., GCA, 2012). The 17O-excess in the SE2 ice core was inversely correlated with the relative humidity in the water vapor source area. These results indicate that the 17O-excess of precipitation in the SE2 core partly preserves information about the relative humidity of the water vapor source. The presentation will also discuss the relationship between the 17O-excess and the meteorological indexes, based on data from additional measurements.
Barkan and Luz, Rapid Commun. Mass Spectrom. 2007; DOI: 10.1002/rcm.3180
Uemura et al., Geophys. Res. Let., 2010; doi:10.1029/2009GL041960
Iizuka et al., BGR, 2021 ; doi : 10.5331/bgr.21R01
Landais et al., GCA, 2012 ; doi:10.1016/j.gca.2011.11.022
The SE-Dome II (SE2) ice core (Iizuka et al., BGR, 2021) drilled in the high accumulation area in south-eastern Greenland were used for isotopic analysis. We measured for ca. 20 year-long record using a cavity ring-down spectrometer. Climatic values of 17O-excess in the SE2 ice core showed a maximum in January-March and a minimum in June-July. The timing and values of the maxima and minima of the SE2 record are well consistent with the 3-year data (2003-2005) from the NEEM ice core in northwest Greenland (Landais etal., GCA, 2012). The 17O-excess in the SE2 ice core was inversely correlated with the relative humidity in the water vapor source area. These results indicate that the 17O-excess of precipitation in the SE2 core partly preserves information about the relative humidity of the water vapor source. The presentation will also discuss the relationship between the 17O-excess and the meteorological indexes, based on data from additional measurements.
Barkan and Luz, Rapid Commun. Mass Spectrom. 2007; DOI: 10.1002/rcm.3180
Uemura et al., Geophys. Res. Let., 2010; doi:10.1029/2009GL041960
Iizuka et al., BGR, 2021 ; doi : 10.5331/bgr.21R01
Landais et al., GCA, 2012 ; doi:10.1016/j.gca.2011.11.022