Optical Properties& Energy Transfer Dynamics of Atmospheric Species

Presenter Information

Daniel K. Havey, James Madison University

Location

Harrisonburg, VA

Start Date

16-5-2012 10:50 AM

End Date

16-5-2012 11:10 AM

Description

Our research group is interested in how light interacts with small molecules and particulate matter that are important to atmospheric chemistry and climate change. An active project currently being performed in the James Madison University Undergraduate Laser Laboratory involves a detailed mapping of energy transfer rates from excited or metastable states of atomic or molecular species. This talk describes a specific example study with potential relevance to the JLAMP VUV/Soft X-ray User Facility that would investigate relaxation dynamics of metastable Krypton atoms using two-photon photoacoustic spectroscopy at 819 nm and 124 nm. A study like this would provide useful reference data to support future development of sensitive trace analyzers for noble gas isotopes.

Presenter Bio

Daniel Havey, Assistant Professor, Chemistry & Biochemistry, James Madison University

Daniel K. Havey did his doctoral work at the University of Colorado in Boulder, studying physical and atmospheric chemistry. In Colorado, he was advised by Professor Veronica Vaida. The Vaida group is one of the world leaders in vibrational spectroscopy of species important to photochemical processes and in chemical reactions occurring on organic aerosols in Earth’s atmosphere. Additionally, he collaborated with Dr. Steven S. Brown at the National Oceanic and Atmospheric Administration’s Earth System Research Lab performing quantitative cavity ring-down spectroscopy measurements of acidic species with importance to atmospheric aerosol chemistry.

Following this, Havey accepted a postdoctoral research position at the University of Maryland in College Park, MD with Professor Amy S. Mullin. The Mullin group is well-known for measurements of relaxation dynamics of high-energy molecules by atmospheric gases (H2O, CO2, etc.). Notable research by Havey at the University of Maryland included development of an innovative method for measuring weak collisions involving CO2 and HOD by means of high-resolution transient IR-absorption spectroscopy at ƛ≈2.7 μm. This work has provided the energy-transfer community with information regarding the state-to-state collisional relaxation dynamics of CO2(g) for these high-probability but poorly understood events.

In 2008, Havey began a two-year appointment as a postdoctoral research associate at the National Institute of Standards and Technology (NIST), working with Dr. Joseph T. Hodges. Research done by Havey at the NIST involved high-fidelity spectroscopic measurements of important atmospheric gases (O2, CO2 , and H2O) and black carbon aerosols. In 2009, Havey, together with Hodges and Daniel Lisak of the University of Nicolaus Copernicus in Torun, Poland, won a competitive NIST Technical Achievement Award for their high-accuracy cavity ring-down spectroscopy of H2O(g). Havey also performed an abundance of experiments to support NASA’s Orbiting Carbon Observatory Program as well as development of a novel approach to photoacoustic spectroscopy (U.S. patent pending).

In Fall 2010, Havey started as an Assistant Professor at James Madison University and has been performing research that investigates the optical properties of gases and aerosol particles which have importance in atmospheric chemistry and climate change. The Havey group currently consists of seven undergraduate researchers and maintains active research collaborations with the NIST, University of Maryland, California Institute of Technology, and University of Nicolaus Copernicus (Torun, Poland).