Research Background


My current research interests focus on field-work measurements of nitrogen oxides in the Arctic within the snowpack and from long-range transport of anthropogenic and boreal wildfire emissions. The Arctic is a remote region but is often impacted by polluted air masses that significantly alter tropospheric composition and the oxidative capacity of the atmosphere. Measuring and monitoring concentrations of ozone precursors is a key element to understanding the changes that have occurred to the production of tropospheric ozone owing to anthropogenic influence, and to determine the long-term stability of the climate. I am interested in assessing the impacts of long-range transported emissions on the Arctic and sub-arctic regions, their effect on the magnitude of tropospheric O3 production and resulting climate and air quality impacts. I have been conducting research at the GEOSummit site in Greenland since July 2008 to study the impact of biomass-burning and anthropogenic impacts on arctic tropospheric chemistry. I am also interested in how large enhancements in nitrogen oxides from long-range transport events affect photochemical processes within the arctic snowpack. This is an area that has received limited attention. However, it is important to assess the relationship between transported pollutants and snowpack photochemistry.

More recently I have developed a new multi-axis DOAS (MAX-DOAS) instrument at Michigan Tech to perform simultaneous measurements of trace gases from multiple viewing directions in both the horizontal and vertical plane. The advantage of this technique is that the range of viewing geometries of the instrument will provide additional information on the spatial distribution of volcanic gas emissions, estimates of plume height and gas fluxes, and information on transport processes and plume dispersal. Optical remote sensing techniques have an advantage over in situ measurements as measurements can be performed at a distance downwind from the volcanic site which allows for availability of data at sites where ground-based measurements are impossible or dangerous to carry out.

My graduate research focused on remote sensing of gases and aerosols within the urban and marine boundary layers. Urban air pollution can easily be transported and there is a need to perform measurements on a large spatial scale with information on the near-surface and free troposphere. As part of this project measurements from a MAX-DOAS intrument were used to validate tropospheric NO2 columns retreived by the satellite-based Ozone Monitoring Instrument (OMI). Using the DOAS measurements I determined a link between the satellite retrieved tropospheric columns and measurements obtained near-surface.


Fieldwork Photos

 

 

Costa Rica (May 2012)

Turrialba Volcano Degassing vent
Turrialba Degassing vent


Toolik Lake, Alaska (Aug 2010)

Brooks_Mountain_Range Toolik_lake_field_station Aurora
Brooks mountain range Toolik Lake Field Station Aurora above camp


Summit, Greenland (Summer 2009)

SunDog flux
Sun Dog Flux Tower