Indian Ocean sea surface temperatures impact precipitation across the basin through coupled ocean‐atmosphere responses to changes in climate. To understand the hydroclimate response over the western Indian Ocean and equatorial east Africa to different forcing mechanisms, we present four new proxy reconstructions from core VM19‐193 (2.98°N, 51.47°E) that span the last 250 ky. Sub‐surface water temperatures (Sub‐T; TEX86) show strong precessional (23 ky) variability that is primarily influenced by maximum incoming solar radiation (insolation) during the Northern Hemisphere spring season, likely indicating that local insolation dominates the upper water column at this tropical location over time. Leaf waxes, on the other hand, reflect two different precipitation signals:
The D/H ratio of epicuticular plant waxes (
- NSF-PAR ID:
- 10447898
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Journal of Geophysical Research: Biogeosciences
- Volume:
- 124
- Issue:
- 7
- ISSN:
- 2169-8953
- Page Range / eLocation ID:
- p. 2107-2125
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Acer rubrum Pinus sylvestris Platanus occidentalis Taxodium distichum Results The air, oven, freeze‐dryer, and microwave drying methods did not affect lipid concentrations significantly, and only a few homologues differed (38.1% or 41.8 μg/g on average) possibly due to biological variations or enhanced extraction efficiencies. The δ13C values were not affected by drying methods, whereas the δ15N values in oven‐dried leaves in some species were higher by 0.2–0.7‰ than those obtained by other methods. Though small, we attribute these patterns to loss of leaf compounds with lower isotope ratios during oven‐drying.
Conclusions Based on our results, each drying technique yielded equivalent results for all plant wax and terpenoid concentrations and bulk leaf δ13C values; however, oven‐drying modified the δ15N values.
