PAOC Colloquium: Daniel Rothman (MIT)

Monday, December 3, 2018 - 12:00

Title: Earth's Excitable Carbon Cycle

Speaker: Daniel Rothmans, Professor of Geophysics, MIT [website]

Abstract: The history of the carbon cycle is punctuated by enigmatic transient changes in the ocean's store of carbon.  Mass extinction is always accompanied by such a disruption, but most disruptions are relatively benign.  The less calamitous group exhibits a characteristic carbon flux whereas greater surges accompany mass extinctions.  But why? Analysis of a two-component dynamical system suggests that disruptions are initiated by perturbation of a permanently stable steady state beyond a threshold.  The ensuing excitation exhibits the characteristic surge of real disruptions.  In this view, the excitation threshold and the characteristic flux are properties of the carbon cycle itself rather than its perturbation.  Surges associated with mass extinction, however, require additional inputs from external sources such as massive volcanism. Modern inputs from anthropogenic emissions may exceed the excitation threshold during the present century.

About this Series: The PAOC Colloquium [PAOCC] is a weekly interdisciplinary seminar series that brings together the whole PAOC community. Seminar topics include all research concerning the physics, chemistry, and biology of the atmospheres, oceans and climate, but also talks about e.g. societal impacts of climatic processes. The seminars take place in 54-923. Lunch is provided after the seminars to encourage students and post-docs to meet with the speaker. Besides the seminar and lunch, individual meetings with professors, post-docs, and students are arranged. Contact the 2018/2019 Coordinators:

Location: 54-915