AOSS Departmental Seminar

October 1, 2009 - 3:30 pm

Prof. Michael J. Prather

Fred Kavli Chair & Professor, Dept. of Earth System Science, University of California at Irvine

Chemical Modes and Feedbacks:  What controls Atmospheric Composition?

The mixture of trace gases and particles in the atmosphere is controlled by the emission, photochemistry and transport of many trace species. Understanding the time scale as well as the chemical and spatial patterns of perturbations to these species is needed to evaluate possible environmental damage (e.g. stratospheric ozone depletion or climate change) caused by anthropogenic emissions of chemically reactive species.  Treating global atmospheric chemistry as a linearized system and analyzing it in terms of eigenvalues gives insight into chemical patterns or modes as well as the time scales of response of the system.  This talk focuses on those chemical feedbacks that couple perturbations across all species.  First results are presented for 3-D modeling of stratospheric chemistry linking both methane and nitrous oxide and for characterization of the one of the longest, important chemical modes in the atmosphere - that coupling N2O, NOy, CH4, and O3. 

AOSS Fall Recruiting Event

October 7, 2009 - 4:30 pm

Earn your BSE in Earth System Science and Engineering. Join us on October 7 to learn how you can be a part of this dynamic department!

Ralph B. Baldwin Award Lecture

October 8, 2009 - 4:00 pm

Please mark your calendars to attend the next presentation of AOSS Departmental 2009 Fall Seminar Series, the Ralph B. Baldwin Lecture on Thursday, October 8, 2009 from 4:00 pm - 5:00 pm in 2246 Space Research Building.

Dr. Alex Glocer
Postdoctoral Fellow, NASA Goddard Space Flight Center

Modeling the Space Environment System: Magnetospheric Composition, Radiation Belts, and Mercury’s Magnetosphere

The space environment is a complex system defined by regions of differing scales, characteristic energies, and physical processes. We utilize several models running together under the Space Weather Modeling Framework (SWMF) to study this highly interconnected system. The methodology and results will be presented for three focused topics: First, we examine the impact of the global system on the radiation belts by integrating the Fok Radiation Belt Environment model (RBE) into the SWMF. The radiation belt model solves the convection-diffusion equation of the plasma in the range of 10keV to a few MeV. In the SWMF, the BATS-R-US magnetosphere model provides the time dependent magnetic field by efficiently tracing the closed magnetic field lines and passing the geometrical and field strength information to RBE at a regular cadence. We use this coupled model to explore radiation belt enhancements observed by the Akebono satellite on September 4, 2008. Our second focus is on ionospheric outflow. We have developed the the Polar Wind Outflow Model (PWOM), and coupled it to various components of the SWMF. The PWOM solves the fieldaligned gyro-tropic transport equations for H+ , He+ , O+ along several field-lines in the altitude range of 250 km to a few Earth Radii. The resulting outflows are put into the multi-fluid and multi-species BATS-R-US model of the global magnetosphere where they can impact the composition and dynamics. The resulting effect on geomagnetic indices, and specific satellite measurements are explored. The final topic we will consider is the interaction of Mercury’s magnetosphere with the active solar wind. NASA’s MESSENGER mission will enter its orbit about Mercury in 2011 and make observations of this magnetosphere during solar maximum when encounters with Interplanetary Coronal Mass Ejections (ICMEs) are most likely. We use the BATS-R-US model, modified to simulate Mercury’s magnetosphere, to investigate the response of this small magnetosphere to ICME conditions.

RECEPTION FOLLOWING

UofM's MRacing Team and Car to Appear on TV

October 10, 2009 - 6:00 am

The University of Michigan Formula One SAE racing team, called MRacing, will be interviewed by Michigan AOSS alum Andrew Humphrey, CBM and their Formula One race car will be shown live on Local 4 News Morning tomorrow (Saturday). Here are the details:

WHAT: MRacing Team and car to appear on live television, to be interviewed by Michigan AOSS Alum and Meteorologist and Reporter Andrew Humphrey

WHEN: Between 6am and 8am, Saturday, October 10, 2009

WHERE:
On Television, WDIV-TV Channel 4.1, Detroit Area
Worldwide Livestreaming Online, http://bit.ly/13uvAb

Michigan Students and Alumni to be Highlighted on Television This Weekend

October 11, 2009 - 6:00 am

This Sunday morning, Michigan AOSS Alum, Meteorologist and Reporter Andrew Humphrey on WDIV-TV Local 4 will show pictures of University of Michigan students and alumni who received awards from the UofM African American Alumni Council. Here are the details:

WHAT: Michigan Students and Alumni Featured By Michigan AOSS Alum, Meteorologist and Reporter Andrew Humphrey on WDIV-TV Local 4

WHEN: 6am - 9am, Sunday, October 11, 2009

WHERE:
On Television, WDIV-TV Channel 4.1, Detroit Area
Worldwide Livestreaming Online, http://bit.ly/13uvAb

Departmental Seminar

October 15, 2009 - 3:30 pm

Jonathan Wright, Postdoctoral Fellow, Columbia University

The Influence of Condensate Evaporation on Atmospheric Humidity: Observations and Model Results

The success of simple advection-condensation models indicates that, to leading order, atmospheric water vapor is controlled by the large-scale temperature and circulation. This suggests that the influence of condensate evaporation is small - but how small? In particular, can it safely be neglected, and in what circumstances? Here, we provide additional constraints on this problem using both observations and model results. First, we examine the interactions between tropical deep convection and upper tropospheric water vapor using data from the Tropical Rainfall Measuring Mission Precipitation Radar and Atmospheric Infrared Sounder satellite instruments. Convective events detraining larger amounts of ice are associated with enhanced upper tropospheric moistening in both absolute and relative terms. In particular, an increase in ice water content of approximately 400% corresponds to a 10?90% increase in the likelihood of moistening and a 30-50% increase in the magnitude of moistening. This influence can be observed up to 48 hours and to order 1000 km from the convective source. Second, we assess the direct effect of condensate evaporation on atmospheric water vapor and its isotopic composition in a climate model. The model contains two parallel hydrologic cycles, an active one which influences the model physics and dynamics and a passive one which does not. We perform two model simulations, one in which passive cloud and precipitation can evaporate and one in which they cannot. The active hydrologic cycles, and thus the simulated circulations and temperatures, are identical in both simulations. Eliminating passive condensate evaporation reduces the specific humidity in the passive cycle by around 5%; this reduction varies from a few percent to 25% of the control value, depending on location.

Departmental Seminar

October 22, 2009 - 3:30 pm

Departmental Seminar

October 29, 2009 - 3:30 pm

Shawn Marshall, Assoc. Professor of Geology, University of Calgary