CHARACTERIZING EL NIÑO-SOUTHERN OSCILLATION SIGNATURES IN ANNUALLY RESOLVED ICE CORES FROM QUELCCAYA ICE CAP (PERU) AND DASUOPU ICE CAP (CHINESE HIMALAYAS) OVER THE LAST 500 YEARS

The El Niño-Southern Oscillation (ENSO) is a quasi-periodic climate anomaly with atmospheric and oceanic properties. Typically, an ENSO event occurs every 2-7 years, and is associated with the failure of the Asian Monsoon. Paleoclimate proxies provide valuable information regarding the dynamics and behavior of the poorly understood ENSO. Two data sets examined for ENSO signatures are annually resolved 500-year climate histories extracted in 2003 from the Quelccaya Ice Cap in the southern Andes of Peru and in 1997 from the Dasuopu Ice Cap in the south-central Himalayas. The derived ENSO proxies are based on the insoluble dust content, oxygen isotopic ratios, and major ionic concentrations. Special attention is focused on the 1790-1793 and 1982-1983 events, which are historically known to be strong ENSO events. While ice cores have been used to study ENSO in the past, our approach differs as we employ two cores located on opposite sides of the Pacific Ocean in an effort to better understand the impacts of ENSO as an event progresses through time and space. This presentation emphasizes our preliminary results.