Also this week, my lab and Department of Geography are hosting a lecture by Dr. Jessica Conroy (Georgia Tech), who'll be discussing her paleolimnological work on dust flux and climate change in Tibet. Jess is a fine young scientist who gives a great talk, so please attend if you'd like!
GEOGRAPHY COFFEE HOUR
Friday. March 23 2012
Coffee & Cookies 3:15 pm, Talk 3:30 pm
"Shaking out the dust: Understanding long-term dust variations and their link to climate in the Himalayas and southern Tibetan Plateau"
Dr. Jessica Conroy, School and Earth and Atmospheric Sciences, Georgia Tech
Dust over the southern Tibetan Plateau and the Himalayas has important feedbacks on glacial melting and the Asian monsoon, but little is know about dust variability over the last millennium. Some paleorecords reveal an increase in 20th century dust hypothesized to be due to human land-use changes, but other studies suggest links between dust variability and large-scale climate modes. In this study we present a 1000-year proxy record of dust from a lake in southwestern Tibet. Our inferred dust record covaries strongly with dust content in Dasuopu ice core, located over 400km to the east of our site. Although the 20th century increase in dust content in Dasuopu is attributed to human activity, our analysis indicates increased dust content covaries with both instrumental and reconstructed summer Arctic Oscillation (AO) index values from AD 1650 to present, with increased dust deposition occurring during more positive AO summers. As the AO is projected to remain in its positive phase in coming decades, we may expect a dusty future in southern Tibet and the Himalayas, with implications for receding Himalayan glaciers and Asian monsoon precipitation.