As the majority of Earth’s energy is received at the tropics the region has huge potential to trigger and/or amplify climate change. Elucidating the role of the tropics in global climate change is essential to constraining future climate trajectories. In particular, new understandings are needed on the relationship between climate change in tropical and extra-tropical regions, and the role of ‘tropical’ forcing in causing ice ages, and abrupt climate variability. There is now compelling evidence for major shifts in tropical temperature and precipitation during the Holocene and particularly over the last few millennia, and this has challenged the prevailing view of tropical climate stability during this time. However, the timing, magnitude and expression of these climate perturbations are highly variable, especially across South America.
Lake sediments are widely accessible natural archives of environmental change in the Andes and they have the potential to provide insights into both long-(millennial) and short-term (decadal) changes in climate. In the tropical Andes, palaeolimnological records have provided evidence of changes in the El Nino Southern Oscillation (ENSO), palaeohydrology and South American monsoon; demonstrating that climate is highly dynamic and modulated by both Pacific and Atlantic Oceans.
The PhD project will target a formerly glaciated region in northern Peru at ~5 degrees S. The student will generate multi-proxy lake sediment records to track ENSO variability over the last 12,000 years, and to provide evidence of palaeohydological changes since deglaciation. As fundamental questions remain about climate variability in the tropical Andes, especially synoptic-scale mechanisms that cause changes in hydroclimate, the studentship will develop answers and insights into the following questions:
1. What is the timing and frequency of ENSO-driven shifts during the late Holocene?
2. What is the magnitude of centennial and millennial-scale climate events since the deglacial?
3. What are the spatio-temporal linkages between ENSO, equatorial Pacific sea surface temperatures and North Atlantic climate variability?