2014 program to study : climate physics and dynamics

Abstract

PrefaceThe 2014 Geophysical Fluid Dynamics Summer Study Program started on June 16th, with the topic of Climate Physics and Dynamics. The topic proved very timely and attracted an unprecedented number of applications from brilliant students. Professors Kerry Emanuel (MIT) and Geoff Vallis (Exeter) gave the principal lectures. They began with the simplest energy balance models and then included adjustment of the vertical profiles by convection (dry and moist). Kerry delved more deeply into convection and the processes found in "cloud-permitting" models, including island effects and the spontaneous formation of clusters surrounded by dry regions. Geoff discussed the larger-scale dynamics of the atmosphere and oceans, including the transports by eddies and the thermohaline circulation. This year, we webcast the principal lectures, with order 50 connections per day from viewers at many universities worldwide.Antonello Provenzale, Raffaele Ferrari, and Glenn Flierl co-directed the summer and invited a large number of top researchers in the dynamics of climate, so that we had a broad critical view on the status of modelling and theory. As usual, the visitors presented new ideas and approaches to geophysical dynamics, and the visitors, staff, and fellows engaged in intense discussions on the porch and in the lecture room. The long-term staff members ensured that the fellows never lacked for guidance; many of them explored unfamiliar topics but were still able to develop new insights. In 2014, the Sears Public Lecture was delivered by Professor Cecilia Bitz, University of Washington, who discussed "The Future of Arctic and Antarctic Sea Ice." She noted that both the Arctic and Antarctic have experienced record sea ice coverage in the last decade. The Arctic has experienced record losses, especially in summer, while the Antarctic has had expanding sea ice. She considers how this is possible in an era of global climate change, and what we can expect in the future. Cecilia overcame problems with the microphone and engaged the audience both in answering question and in discussions at the reception and refreshments following the talk.Anne Doucette, Julie Hildebrandt, and Janet Fields made sure that the administrative side of the program ran with admirable efficiency. Matt Barton ensured the webcast was high quality. We continue to be indebted to WHOI for their support and to the Academic Programs Office, who once more (with the cooperation of the weather!) provided a perfect atmosphere.i ii Principal LecturesKerry Fellows' Reports PreambleAs opposed to expectations, there is not going to be much GFD in this lecture. There will be no equations of motion. The reason is that to understand climate, it is necessary to merge understanding of the large-scale motion with the thermodynamics and specifically with radiative transfer. Most problems that have not been solved in climate science are connected to the interaction of radiative transfer with water substances. This lecture will therefore review how radiation passing through ...

A Recharge Oscillator Model for Interannual Variability in Venus’ Clouds

“…Since a significant fraction of thermal flux from the top of the convective layer escapes directly to space through the relatively more transparent upper clouds (Lebonnois et al, 2015), we make the assumption that the temperature at the top of the convective cloud remains a constant irrespective of cloud-base temperature so that the net thermal flux above the clouds is invariant. So, if the cloud-base temperature changes by an amount ΔT , to keep the convective cloud top temperature constant, the convective cloud top height must change by an amount ΔL given by (Vallis et al, 2015):…”