Boulter research group

Kirsten Strobush, Senior

Skye Doering, Junior

Anna Volkert, Senior

View our poster from the 2007 ACS National Meeting in Chicago (pdf).

RESEARCH INTERESTS

My group’s current research activities are focused on laboratory investigations related to low-temperature chemistry of the terrestrial middle atmosphere and of extraterrestrial planetary atmospheres.  Specifically, I am interested in heterogeneous chemistry, or chemical interactions that occur at the interface between atmospheric gases and particle surfaces.  These ice particles typically form at temperatures of 0 to -200 degrees Celsius, although we usually work at temperatures significantly below -50° C.  Our research goals are to grow ice films with varied chemical compositions (including water, ammonia, hydrogen sulfide and methane).  The films are grown in the laboratory under tightly controlled experimental conditions, and are then observed with various analytical tools as they are exposed to different gaseous chemical species in order to characterize the chemical interactions that occur at the surface.

TERRESTRIAL ATMOSPHERIC ICES (WATER)

In Earth's middle atmosphere (between 60 and 90 km), particles are generally composed either of mineral materials resulting from meteors “burning up” as they enter the atmosphere or tiny water ice particles (often referred to as noctilucent clouds or polar mesospheric clouds) that form during the summertime near the poles at altitudes of about 83 km.  In collaboration with investigators at SRI International in Menlo Park, CA, we are studying chemical reactions of atomic oxygen on the surface of these polar mesospheric clouds which may affect their formation, structure, and lifetime.  One reason for our interest is that other investigators have suggested that either the frequency with which these clouds are observed or their brightness may be indicators of climate change in a region of the atmosphere which is less comprehensively studied.  This research is funded by a grant from NASA Geospace Sciences.  This work will help to support the scientific goals of the AIM (Aeronomy of Ice in the Mesosphere) satellite mission, to be launched in mid-April, 2007.

EXTRATERRESTRIAL ATMOSPHERIC ICES

The visible disk of Jupiter is completely covered with clouds.  However, its atmospheric composition leads to the formation of ammonia ice clouds, which are are formed as mixtures with other components such as water, hydrogen sulfide, and hydrocarbons.  Possible species of upper-atmospheric ices include pure ammonia, ammonium hydrosulfide and various hydrates of those two.  It has been suggested that complex hydrocarbon hazes may adsorb strongly to these particles, obscuring their spectral signature.  In our lab, we utilize a high-vacuum chamber to deposit ice films of these chemical species in order to study their spectral signatures and other structural properties of the resulting mixed ices.  These laboratory results may be compared to telescopic and remote observations and then assembled in computer models by other researchers to better understand the atmospheric chemistry and physics of these fascinating giant planets.  Because these atmospheres are much less comprehensively observed and studied than our own, the application of techniques previously developed for studying the terrestrial atmosphere to new problems in extraterrestrial atmospheres should lead to significant advances.  This research is supported by a Research Corporation Cottrell College Science award.

CHAMBER SCHEMATIC DIAGRAMS

High-vacuum chamber: side view schematic diagram

High-vacuum chamber: top view schematic diagram

 

James E. Boulter, Ph.D. Department of Chemistry Phillips 450 105 Garfield Avenue Eau Claire, WI 54702 (715) 836-4175 boulteje@uwec.edu	last updated: 11 February 2008