The Lamont 75th Anniversary Earth Science lectures highlight distinguished alums and former staff as they present their groundbreaking research and reflect on what makes LDEO unique.
Presents:
A Signal-to-Noise Paradox in Climate Change
with Dr. Mark A. Cane, G. Unger Vetlesen Professor of Earth and Climate Sciences, Emeritus, Ocean and Climate Physics, Lamont-Doherty Earth Observatory, + Amy Clement, Jeremy Klavans, Chengfei He, Lisa Murphy.
Abstract
Paradox: a seemingly absurd statement that when investigated may prove to be true.
Regional modes of climate variability that have consequential impacts on temperature and rainfall over land have historically been understood as natural, random fluctuations in the ocean- atmosphere system. However, there is strong agreement between the observed time history of these modes and their response to radiative forcing as simulated in climate models, suggesting that the ‘signal’ of radiative forcing is an important part of their observed behavior. The question we address here is how big is the radiatively forced signal in the real world and whether its magnitude is faithfully represented in models. We find that models consistently produce radiatively forced variability that is too weak – often far too weak – compared to a best estimate of observed forced variability. The implication is that models misrepresent the degree to which climate variability is radiatively forced and hence that they understate the predictability of climate. Labeling the radiatively forced part as “signal” and the internal variations as “noise”, this is the signal to noise problem in climate modes.
Host: Dr. Richard Seager, Palisades Geophysical Institute/Lamont Research Professor, Ocean and Climate Physics, Lamont-Doherty Earth Observatory.
The Earth Science Colloquium Series, sponsored by Lamont-Doherty Earth Observatory and Columbia University Department of Earth and Environmental Sciences (DEES), provides a lively forum for discussing a wide variety of topics within the Earth sciences and related fields. Colloquia are attended by the full range of scientific and technical staff at LDEO. Colloquium attendance is required of all pre-orals DEES graduate students. The Colloquium Series supports the Lamont Seminar Diversity Initiative.
