Holocene Sun-Monsoon Linkage Recorded in Stalagmites From Oman
Abstract
In order to reveal a possible sun-climate connection well-dated and highly resolved climate records from key-localities are necessary. Such records can be gained from Uranium-series dated stalagmites from Oman, where climate is still strongly influenced by the Indian monsoon. Two high-resolution oxygen isotope profiles derived from Th-U-dated stalagmites from Hoti Cave (23° 05N, 57° 21E; 800 masl) in Northern Oman and Qunf Cave (17° 10N, 54° 18E; 650 masl) continuously cover the period between 10.1 and 6.2 kyr B.P. and 10.5 and 2.7 kyr B.P respectively. The temporal resolution of these oxygen isotope profiles averages 4 and 5 years for stalagmites H5 (Hoti Cave) and Q5 (Qunf Cave) respectively. We assume that oxygen isotope ratios (\delta18O) of stalagmite calcite primarily reflect variations in the amount of monsoon rainfall (the so-called "amount effect"), with more negative \delta18O values reflecting higher monsoon rainfall due to changes in monsoon intensity and/or convective activity within the ITCZ. The high temporal resolution of both speleothem \delta18O records enables a precise comparison with atmospheric \Delta14C measured in tree-rings. The similarity between the \delta18O and \Delta14C time series at multi-decadal timescales, both in their general pattern and in the number of peaks, suggests that higher monsoon rainfall in Oman coincides with higher solar activity and vice versa. Because much of the variation in \Delta14C at these timescales is attributed to solar forcing through variations in solar activity, the data reveal a possible close sun-monsoon connection.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2004
- Bibcode:
- 2004AGUFM.U42A..07M
- Keywords:
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- 9320 Asia;
- 3344 Paleoclimatology;
- 1854 Precipitation (3354);
- 1045 Low-temperature geochemistry;
- 1650 Solar variability