ESSL LAR

Thomas Karl

 

Scientist II
TIIMES - ACD
BEACHON

 

Contact Information:
PO Box 3000, Boulder, CO 80307-3000
Office: FL0 - 3168
Telephone: 303-497-1884
Email: tomkarl@ucar.edu
Home Page

Thomas Karl
 

Project Summary:

 

CHATS field site

CHATS Field Site

TIIMES research in 2007

T. Karl's previous TIIMES research has focused on deploying Proton-Transfer-Reaction Mass Spectrometry (PTRMS) for flux measurements of volatile organic compounds (VOC) released from vegetation. In particular tropical landscapes are thought to be responsible for about 80% of global biogenic VOC emissions and yet are among the least understood. Results from a 2004 field campaign in the Amazon (The Chemistry And Production Of Smoke - CAPOS) have recently been published in the Journal of Geophysical Research (J. Geophys. Res., 112, D18302, doi:10.1029/2007JD008539).

T. Karl deployed a PTR-MS instrument during the Canopy Horizontal Array Turbulence Study (CHATS) which took place in Dixon, CA, from mid-March to mid-June, 2007. The experimental design of CHATS was multi-faceted, with a key component of the program to characterize the impact of tall vegetation on the spatial structure of canopy turbulence. The focus for chemically reactive compounds was to investigate chemistry of VOCs inside the canopy and to gain insights on how this would impact fluxes measured on top of the canopy. Data analysis is currently ongoing.

 

Future Plans

As part of TIIMES BEACHON program T. Karl's future research activities will include and address the following science questions:

  • What are the dominant semivolatile VOC emissions that influence the secondary organic aerosol in the atmosphere?

  • How does land-use change perturb the biosphere-atmosphere exchange of reactive trace gases?

  • Which satellite landcover database gives the most appropriate representation to map trace gas emissions patterns on to different land cover classifications?

  • Can fluxes of volatile organic compounds be measured on urban footprints and can airborne measurements be used to constrain urban emissions?

  • How does the vertical exchange between the PBL and FT influence the distribution of trace gases and aerosols over land - how well can entrainment rates be parameterized?

  • How do clouds influence the distribution of reactive VOCs and their oxidization products - can segregation effects be quantified?
 

Community Service:

  • Scientific committee member - Division on Atmospheric Sciences (AS), Subdivision AS2: Boundary Layer Processes, European Geosciences Union
 

Presentations:

  • Investigating Volatile Organic Compounds Emitted from Natural Landscapes and their Impact on Atmospheric Chemistry, Boston, Harvard USA, June 2007
 

TIIMES External Collaborators:

Mark Adams, University of New South Wales
A. Arneth, Lund University - Geobiosphere Science Centre - Dept. of Physical Geography & Ecosystems Analysis
Paulo Artaxo, University of São Paulo
Elliot Atlas, Rosenstiel School of Marine and Atmospheric Science
Donald Blake, University of California, Irvine
Peter Busek, University of Arizona
Ted Christian, University of Montana-Missoula
Ted Christian, United States Forest Service (USFS), University of Missouri
Joost DeGouw, National Oceanic & Atmospheric Administration (NOAA)
D.W.T. Griffith, University of Wollongong
Wei Min Hao, United States Forest Service (USFS) - Missoula Fire Lab
Detlev Helmig, University of Colorado
John Holloway, National Oceanic & Atmospheric Administration (NOAA)
Kolby Jardine, Stony Brook University
Jose Jimenez, National Oceanic & Atmospheric Administration (NOAA)
Brian Lamb, Washington State University
Ray Leuning, Commonwealth Scientific & Industrial Research Organisation (CSIRO) - Centre for Complex System Science
Simin Maleknia, University of New South Wales
Mark Potosnak, Desert Research Institute
Rei Rasmussen, Oregon Health & Science University
Daniel Riemer, Rosenstiel School of Marine and Atmospheric Science
Tanja Suni, Commonwealth Scientific & Industrial Research Organisation (CSIRO) - Centre for Complex System Science
Carsten Warneke, National Oceanic & Atmospheric Administration (NOAA)
Paul Wennberg, California Institute of Technology (CalTech)
Alfred Wiedensohler, Leibniz-Institute for Tropospheric Research
Robert Yokelson, University of Montana-Missoula
Bob Yokelson, United States Forest Service (USFS), University of Missouri
 

Publications:

Karl, T., A. Guenther, R. J. Yokelson, J. Greenberg, M. Potosnak, D. R. Blake, P. Artaxo, 2007: The tropical forest and fire emissions experiment: Emission, chemistry, and transport of biogenic volatile organic compounds in the lower atmosphere over Amazonia. J. Geophys. Res., American Geophysical Union, 112, D18302, doi: 10.1029/2007JD008539.

Karl, T. G., T. J. Christian, R. J. Yokelson, P. Artaxo, W. M. Hao, A. Guenther, 2007: The tropical forest and fire emissions experiment: method evaluation of volatile organic compound emissions measured by PTR-MS, FTIR, and GC from tropical biomass burning. Atmos. Chem. Phys. Discuss., 7, 8755-8793.

Yokelson, R. J., T. Karl, P. Artaxo, D. R. Blake, T. J. Christian, D. W. T. Griffith, A. Guenther, W. M. Hao, 2007: The Tropical Forest and fire emissions experiment: overview and airborne fire emission factor measurements. Atmos. Chem. Phys. Discuss., 7, 6903-6958.