Andrew Turnipseed

Project Scientist
TIIMES - ACD
BEACHON

Contact Information:
PO Box 3000, Boulder, CO 80307-3000
Office: FL0 - 3150
Telephone: 303-497-1448
Email: turnip@ucar.edu

Project Summary:

Since TIIMES originated, my research has involved studying the ecosystem-level biosphere-atmosphere exchanges of ozone (O3), oxides of nitrogen (NO, NOx, NOy), sulfur dioxide (SO2) and volatile organic carbon compounds (VOCs) using a variety of micrometeorological techniques.   To this end during FY06-07 I participated in two field campaigns (EUCAP 06 and CHATS 07), continued longer-term measurements at the Niwot Ridge AmeriFlux site and assisted in obtaining preliminary data (O3, SO2) at the Manitou Springs Experimental Forest.  The latter will be used to assess the viability of this site as a possible long term research site for TIIMES.

At the two field studies, I implemented a system designed to interface with a variety of trace gas sensors to measure concentration profiles through-out and above a plant canopy.  When combined with turbulence data, these profiles can be used to infer fluxes as well as source and sink distributions of the species designated above.  We also developed a system to measure eddy covariance fluxes of ozone above the canopy at two heights to discern divergences in the flux and what might be causing these divergences.  We also made fast eddy covariance measurements of NO and NOx for the first time.  We hope that these studies serve as a model for future instrument deployments, integrating fast eddy covariance measurements above the canopy with concentration profiles in order to fully understand within-canopy processes and their impact on measured fluxes.

A third project involved deploying an REA system for VOC flux measurements at the Niwot Ridge AmeriFlux site.  This system was initially tested during the EUCAP campaign.  The goal of the Niwot Ridge project was twofold: (1) to investigate the usefulness of making a few weekly flux measurements (not temporally continuous) to deduce seasonal ecosystem emission characteristics which often go unobserved during short intensive campaigns and (2) to test this prototype REA with the hope of reproducing and deploying similar systems at a variety of sites to enhance our VOC emission data base both spatially and temporally.  This data base is necessary in order to validate and tune models such as MEGAN designed to simulate global VOC emissions.  Preliminary results at Niwot Ridge seem to indicate that environmental factors other than just temperature (as would be predicted from current MEGAN estimates) may play a very important role.  Phenological changes (new plant growth) and short term disturbances (for example, hailstorms) seem to play an important role in governing total VOC emissions at this subalpine site.  The Figure 1 shows the seasonal trend for a-pinene, a primary terpenoid VOC observed at this site.

TIIMES External Collaborators:

Dean Anderson, United States Geological Survey (USGS)
Stefan Bauer, Leibniz-Institute for Tropospheric Research
Peter Blanken, University of Colorado
Sean Burns, University of Colorado
Ron Cohen, University of California, Berkeley
Mhairi Coyle, Centre for Ecology and Hydrology
Joost deGouw, National Oceanic & Atmospheric Administration (NOAA)
Ian Faloona, University of California, Davis
Delphine Farmer, University of California, Berkeley
Beatrice Gardenia, El Centro Nacional de Investigación y Capacitación Ambiental (CENICA)
Steve Garrity, University of Idaho
Greg Huey, Georgia Institute of Technology
William Kuster, National Oceanic & Atmospheric Administration (NOAA)
Brian Lamb, Washington State University
Noah Molotch, University of California, Los Angeles
Russell Monson, University of Colorado
Eiko Nemitz, Centre for Ecology and Hydrology
Jeremie Pean, University Paul Sabatier
Shelley Pressley, Washington State University
Zoran Ristovski, University of Brisbane
Paul Shepson, Purdue University
Jed Sparks, Cornell University
Tanja Suni, University of Helsinki
Lee Vierling, University of Idaho
John Walker, Evironmental Protection Agency (EPA)
Birgit Wehner, Leibniz-Institute for Tropospheric Research
Mark Williams, University of Colorado
Paul Woodbridge, University of California, Berkeley
Chiuxiang Yi, University of Colorado

Publications:

Sun, J., S. P. Burns, A. C. Delaney, S. P. Oncley, A. A. Turnipseed, B. B. Stephens, D. H. Lenschow, M. A. LeMone, R. K. Monson, D. E. Anderson, 2007: CO2 Transport over Complex Terrain. Agric. For. Meteorol., 145, 1-21, doi: 10.1016/j.agrformet.2007.02.007.

Molotch, N. P., P. D. Blanken, M. W. Williams, A. A. Turnipseed, R. K. Monson, S. A. Margulis, 2007: Estimating sublimation of intercepted and sub-canopy snow using eddy covariance systems. Hydro. Proc., 21 (12), 1567-1575, doi: 10.1002/hyp.6719.

Burns, S. P., R. K. Monson, M. V. Losleben, A. A. Turnipseed, M. W. Williams, N. P. Molotch, 2006: Measurements of snowpack temperature in a Colorado subalpine forest. 2006 Fall Mtg., AGU.