Introduction

My research interests are in past, current and future climate change in the tropics. I am particularly interested in trying to bridge the gap between modern climate dynamics studies and paleoclimatic interpretation of proxy data. Therefore my research is very interdisciplinary in nature and often forms part of larger international collaborative programs. In my research I tend to focus on two regions in particular: the tropical and subtropical Andes in South America and the mountains of East Africa. In both locations a wealth of paleoclimatic information is available from a large number of natural archives, but the understanding of their climatic sensitivity is often inadequate. Some of the most important natural archives are based on stable isotopic proxies (e.g. tropical ice cores, speleothems or biomarkers in lake sediments), but it is often not clear what these proxies really record and what their climatic sensitivities are in both the time- and space domain. I try to investigate how these sensitivities may change in time as boundary conditions change and if lessons learned from climate studies on interannual to interdecadal timescales can be used in the interpretation of centennial to millennial scale climate variability recorded in these proxies. To answer some of these questions I employ both observational data (in-situ measurements, reanalysis, radiosonde and satellite data) and models of varying complexity (GCMs, RCMs and isotopic models). In the past this research has been funded through grants from NSF (Earth System History, Paleoclimate and Climate Dynamics) and NOAA (Climate Change Data and Detection, CCDD).

I also maintain an active research program studying the causes, impacts and scenarios of future climate change in the tropical Andes, where the retreat of glaciers may soon pose a threat for the regional water supply. I employ regional climate models (RCMs) over the tropical Andes to study how glacier extent and runoff from glacierized catchments will change under different scenarios as predicted in the IPCC-SRES (Special Report on Emissions Scenarios). This research is funded through NSF (co-funded by Hydrology and Climate Dynamics Divisions) and the Inter-American Institute for Global Change Research (IAI). I am also collaborating with the Latin America Division of the Word Bank, which has a particular interest in this kind of research and funding through the Global Environmental Fund (GEF) to implement adaptation measures in several Andean countries.

Research Interests

Climate variability and climate change in tropical South America and East Africa, tropical glacier-climate interactions, tropical paleoclimatology.