Author : Karl Steven Philippoff
Publisher :
ISBN 13 :
Total Pages : 194 pages
Book Rating : 4.:/5 (88 download)
Book Synopsis An Investigation Into the Causes of D180 Variations in the Dasuopu Ice Core, Central Himalayas, Using Coral Composites and Instrumental Data by : Karl Steven Philippoff
Download or read book An Investigation Into the Causes of D180 Variations in the Dasuopu Ice Core, Central Himalayas, Using Coral Composites and Instrumental Data written by Karl Steven Philippoff and published by . This book was released on 2014 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The interpretation of variations in oxygen isotopes ( d18O) within tropical ice core records have been a subject of much debate. In this study the ice core record from Dasuopu (28 23 N, 85 43 E) in the central Himalayas was compared with two coral composite records derived from Indian (Chagos Islands, Mafia, Mahe, Malindi, and Mayotte) and Pacific (Kiritimati, Maiana, Nauru, Palmyra, and Tarawa) Ocean corals, precipitation data from the Global Precipitation Climatology Center (GPCC) v6 and Indian monsoon subdivisions, the Nino 3.4 index, sea surface temperature (ERSST v3b), and air temperature data (NCEP 20th century reanalysis) to examine its relationship over interannual, 2-8 year, and multi-decadal timescales. Coral records represented reliable, consistent, and highly resolved proxy records of SST variability over the length of their respective records and provided a comparison for the results derived from the SST reconstructions. The results from these analyses indicate that the Dasuopu record can be best understood in a hierarchical manner. Over interannual and 2-8 year timescales, the variability of the Dasuopu oxygen isotopic record is dominated by local and regional rainfall variability which are both strongly associated with the variations in the strength of El Nino-Southern Oscillation (ENSO). However, over decadal and especially multi-decadal timescales, the variation in its isotopic record is strongly driven by long-term trends in air and sea surface temperature in regions upwind of the ice core location. These relationships were highly significant and were observed in both the coral composite and instrumental datasets, making these results more robust. A multi-regression model constructed using the summer monsoon rainfall from the East Uttar Pradesh monsoon subdivision, the summer mean Nino 3.4 index and air temperature anomalies in a region bound by 20-28 N, 80-88 E described 27% of the variance in the Dasuopu d18O record between 1886 and 1996, with temperature the most important parameter. This strongly suggests that these three parameters control a large degree of the variability observed in the Dasuopu d18O record over this time frame.
