- Winter Break - no CLaSP seminar
- CLaSP Seminar Series - Dr. Qing Yue
- CLaSP Seminar Series - Professor Kerry Emanuel
- CLaSP Seminar Series - Professor Noah Diffenbaugh
- CLaSP Seminar Series - Dr. Orenthal Tucker
Winter Break - no CLaSP seminar
March 2, 2017 - 3:30 pm
The University of Michigan is on Winter Break this week. The CLaSP Seminar Series will return next week. See you then!close
CLaSP Seminar Series - Dr. Qing Yue
March 9, 2017 - 3:30 pm
Our guest this week will be Dr. Qing Yue, research scientist at NASA's Jet Propulsion Laboratory. Please join us!
Title: "Estimating Short-term Cloud Radiative Feedback from A-Train"
Abstract: Cloud radiative feedback (cloud feedback) has been identified as the major source of inter-model spread on climate sensitivity and future climate projections in response to increased greenhouse gases. Recent studies show the short-term cloud feedback estimates are highly correlated with their long-term counterparts (e.g. Zhou et al. 2015, Colman and Hansen 2016, Yue et al. 2016). Therefore, it is plausible to use the short-term cloud feedback calculated from satellite observations to constrain the model-based results and understand the cloud feedback mechanisms. However, the short-term cloud feedback estimated from satellite observations suffers from very large uncertainties and weak signals, which are due to the uncertainty on the cloud and radiative flux observations, and the compensation from different cloud types, regions, and altitudes where cloud change occurs as a response to climate variations. In the current study, we estimate the short-term cloud feedbacks by cloud type as well as their uncertainties from A-Train using the observation-based cloud radiative kernel (CRK) method (Yue et al. 2016). The multi-sensor observations obtained from A-Train satellites have been collocated at the pixel scale to derive both the CRKs and the cloud cover response (Yue et al. 2016) to maintain the consistency between radiative kernels and climate responses.close
CLaSP Seminar Series - Professor Kerry Emanuel
March 16, 2017 - 3:30 pm
Professor Kerry Emanuel, co-founder of the Massachusetts Institute of Technology's Lorenz Center, Please join us!
Title: "How Will Climate Change Affect Severe Thunderstorms?"
Abstract: Severe thunderstorms produce hail, tornadoes, strong straight-line winds, and flash floods. They are particularly problematic in the U.S., which has a higher frequency of such storms than any other nation. Up until now, we have lacked a comprehensive theory for how climate change might affect the incidence and magnitude of severe thunderstorms. I will describe some recent work done in collaboration with my PhD student Vince Agard which suggests that the severity of thunderstorms may increase as the planet warms.
Bio: Dr. Kerry Emanuel is the Cecil and Ida Green professor of atmospheric science at the Massachusetts Institute of Technology, where he has been on the faculty since 1981, after spending three years on the faculty of UCLA. Professor Emanuel's research interests focus on tropical meteorology and climate, with a specialty in hurricane physics. His interests also include cumulus convection, and advanced methods of sampling the atmosphere in aid of numerical weather prediction. He is the author or co-author of over 200 peer-reviewed scientific papers, and three books, including Divine Wind: The History and Science of Hurricanes, published by Oxford University Press and aimed at a general audience, and What We Know about Climate Change, published by the MIT Press. He is a co-director of MIT’s Lorenz Center, a climate think tank devoted to basic, curiosity driven climate research.close
CLaSP Seminar Series - Professor Noah Diffenbaugh
March 23, 2017 - 3:30 pm
Our guest for this week's CLaSP Seminar Series is Professor Noah Diffenbaugh, senior fellow at the Stanford Woods Institute for the Environment. Please join us!
Title: "Quantifying the influence of observed global warming on the probability of historically unprecedented extreme climate events"
Abstract: Effective climate risk management requires robust quantification of the probability of different kinds of hazards, such as heat waves, droughts, floods, and severe storms. As a result, there has been increasing interest in the extent to which historical global warming has influenced the occurrence and severity of individual extreme climate events. However, although trends in the extremes of the seasonal- and daily-scale distributions of climate records have been analyzed for many years, quantifying the contribution of observed global warming to individual events that are unprecedented in the observed record presents a particular scientific challenge. I will describe a framework for leveraging observations and large climate model ensembles to quantify the influence of observed global warming on the probability of unprecedented extreme events. This approach is grounded on three tenets: (1) Focus on understanding the physical causes of the individual event; (2) Use formal uncertainty quantification to test the probability of those physical conditions occurring in the current climate; and (3) Use formal hypothesis testing to compare the probability of those physical conditions occurring in the current climate and a climate without human influence. My group has applied our analysis to a number of different climate variables from a number of individual events, including temperature, precipitation, soil moisture, and atmospheric circulation patterns. Together, this work has shown that global warming can influence the risk of extreme events that are unprecedented in historical experience, particularly by altering the probability of the physical conditions that are responsible for the event. In addition, given the widespread public interest in “real time” attribution, the prospects for operational attribution analysis will also be discussed.
Bio: Noah Diffenbaugh is a Professor at Stanford University. He studies the climate system, including impacts on agriculture, water resources, and human health. He is currently Editor-in-Chief of Geophysical Research Letters. He has served as an IPCC Lead Author, and has provided scientific expertise to the White House, the Governor of California, and U.S. Congressional offices. Recognitions include the Holton Award from the American Geophysical Union and a CAREER award from the National Science Foundation.close
CLaSP Seminar Series - Dr. Orenthal Tucker
March 30, 2017 - 3:30 pm
Our guest for this week's CLaSP Seminar Series is Climate & Space research scientist Dr. Orenthal Tucker. Please join us!
Title: "Titan’s Escaping Atmosphere: Insights from Cassini"
Abstract: The Cassini mission has acquired a wealth of data on Titan's upper atmosphere during observations from over 100 Titan flybys. Vertical density profiles measured by the Ion Neutral Mass Spectrometer (INMS) indicate that the structure of the upper atmosphere is highly variable. In this seminar, I will discuss ideas on the capability of the interaction of precipitating ions from Saturn’s magnetosphere on driving such variability and current ideas on the neutral particle escape rate. The INMS density data can be roughly fit using several different energy distribution functions to describe the neutral gas densities (N2, CH4) in the transitional region of the upper atmosphere. These result in different conclusions on the thermal structure, energy deposition and escape.
I will discuss the results obtained from gas-kinetic models that can be relied upon to correctly interpret the dynamics implied by such fits of the density data. Since similar issues apply to the upper atmospheres of most planetary bodies, tests of simulations of the thermal structure and escape rates for Titan’s upper atmosphere, through which the Cassini spacecraft has made multiple passes, are critical.close