Winter 2018

Winter 2018

Tuesday Afternoons at 3:30 PM
Nat Sci Annex 101

January 9, 2018

Speaker: IRES Students, UCSC

Title: Summer Research Project in Israel

Host: Adina Paytan

January 16, 2018

Speaker: Juan Lora, UCLA

Title: Glacial hydroclimate of North America: the mid-latitude jet, moisture transport, and atmospheric rivers

Host: Francis Nimmo

January 23, 2018

Speaker: George Allen, JPL

Title: Estimating the Global Abundance of Rivers and Streams from Space

Host: Margaret Zimmer

January 30, 2018

Speaker: Colin Meyer, University of Oregon

Title: Mechanics of ice stream shear margins

Host: Slawek Tulaczyk

February 6, 2018

Speaker: Cheng Li, Cal Tech

Title: The First Year of Juno Observing Jupiter’s atmosphere

Abstract: It’s been more than a year since the Juno spacecraft arrived at Jupiter. The Juno Microwave Radiometer measured the Jovian tropospheric radiation from the north pole to the south pole. The JunoCAM pictured Jupiter’s polar clouds for the first time. On July 11th, 2017, the Juno spacecraft flow over the Great Red Spot, sensing the atmosphere down to at least 200 bars. And, these are only part of the results that the Juno mission has revealed. In this talk, I will introduce Juno’s new discoveries of Jupiter’s atmosphere including the ammonia distribution, the polar vortices and the structure of the Great Red Spot. New spectral inversion techniques are developed and applied to invert the Juno Microwave Radiometer observations. Shallow water models are used to study the stability of the polar vortices. Order-of-magnitude calculations are performed to speculate the dynamics of the GRS. What we learned is a whole new Jupiter.

Host: Xi Zhang

February 13, 2018

Speaker: Elliott Campbell, UCSC

Title: Understanding Earth's Coupled Carbon, Water, and Energy Cycles Using Atmospheric Carbonyl Sulfide

Abstract: Terrestrial photosynthesis is the fundamental process that converts carbon dioxide, water, and sunlight into chemical energy, resulting in a coupling between global cycles of carbon, water, and energy. The rate of photosynthesis is driven by incoming radiation and water availability, modulates atmospheric carbon dioxide, and in turn releases water vapor that can drive cloud distributions and rainfall. There is an urgent need to improve our understanding of photosynthesis processes because they currently create one of the largest uncertainties in climate change projections.  However, conventional measurements of photosynthesis are insufficient for the task because they are limited to small spatial and temporal scales.  To address this knowledge gap, I will present new global scale information on photosynthesis derived from analysis of atmospheric carbonyl sulfide.  This approach draws on satellite, ice core, and air-monitoring data to provide a new window into the global carbon cycle, and potentially, a revolution in our understanding of carbon-climate feedbacks.

Host: Jim Zachos

February 20, 2018

Speaker: Mark Denny, Stanford

Title: Mechanistic Predictions: Prospects and Problems in the Quest for Reality

Host: Noah Finnegan

February 27, 2018

Speaker: Sarah Stewart, UC Davis

Title: Raining a Magma Ocean: Thermodynamics of Earth after the Last Giant Impact

Abstract: Giant impacts partially vaporize rocky planets. Earth’s outer layers after the Moon-forming giant impact were sufficiently hot that volatiles and silicates were dissolved into a single fluid. As the body cooled, the silicate liquid and volatile gases separated into distinct phases. The initial partitioning of volatiles between the newly-formed magma ocean and atmosphere is determined by the evolution of the pressure-temperature profile through the body coupled to the internal dynamics, which is strongly influenced by rotation. I will present the thermodynamic path that Earth followed while cooling from a vaporized body to a magma ocean near the liquidus. The volatile content of the magma ocean at the time of freezing is likely determined by dissolution during the giant impact and limited re-equilibration at the magma ocean-atmosphere interface.

Host: Jonathan Fortney

March 6, 2018

Speaker: Susannah Dorfman, COMPRES Distinguished Lecturer, Michigan State University

Title: The Mineral Physics Test Kitchen: Recipes for Earth’s Mantle and Core

Abstract: The interiors of Earth and other planets were “cooked” by processes of accretion and differentiation and can be “tasted” by geochemical sampling at the surface and remote geophysical observations of physical properties at depth. Mineral physics experiments and simulations seek to reverse-engineer the recipes that generate the features we detect in the deep Earth today. Because Earth and other planets are almost entirely composed of materials at high pressures and temperatures, the key to translating geophysical observations to structure and composition is the dependence of mineral stability and physical properties such as density, elasticity, and transport properties on composition and thermodynamic conditions. I will discuss recent observations of chemical reactions and properties of minerals relevant to Earth’s mantle and core, and implications of these experiments for the compositions of layers and regions in the deep Earth.

Host: Cara Vennari

March 8, 2018 - Special Seminar - held at 12:00PM (noon) in ISB 102

Speaker: Scott Wing, Smithsonian

Title: Fossil Atmospheres Project: Improving Plant-based pCO2 Proxies for Greenhouse Periods.

Host: Jim Zachos

March 12, 2018 - Special Seminar - held at 12:00PM (noon) in E&MS A340

Speaker: Tamara Pico, Harvard

Title: The glaciation of North America: Insights from sea-level change and river evolution

Host: Jim Zachos

March 13, 2018

Speaker: Jerry Mitrovica, Harvard

Title: Resolving Munk's Enigma of Global Sea Level Rise

Host: Jim Zachos