A BIOMARKER RECORD OF PALEOCLIMATE AND ENVIRONMENTAL CHANGE IN TROPICAL NORTH AMERICA FROM THE SEDIMENTS OF LAKE CHALCO, MEXICO

Anthropogenic climate forcing is expected to result in lower precipitation in the heavily populated Mexico City region, which is home to over 20 million people and contains Lake Chalco, as well as an increase in the frequency and severity of droughts. The location is affected by changes in sea surface temperature in the Pacific and Atlantic basins as well as migration of the Intertropical Convergence Zone, westerlies, and the North American Monsoon. At an altitude of 2240m above sea level which is characteristic of much of western North America, it provides a crucial starting point for understanding the enormous hydrological variability in tropical and subtropical North America. Prior climate-based research in the area has concentrated on examining extensive climatic data that are grouped in southern North America and the Caribbean. They have demonstrated a connection between droughts in southern North America and variations in tropical Pacific Sea surface temperatures, and they also raise the possibility that patterns in the circulation of the Atlantic Ocean may have contributed to previous climatic variability. My research aims to present biomarker data for reconstructing precipitation (the distribution and stable isotope composition of leaf waxes), and temperature (branched glycerol dialkyl glycerol tetraether lipids, brGDGTs) from sediments of Lake Chalco. This study will improve our understanding of neotropical climate change which will also help us better comprehend climatic and hydrological variability in one of the world's densest urban areas.