Dr. Gunnar W. Schade

Research Interests

Our main current project is the measurement of energy and trace gas fluxes in an urban area (click the link to that project on the right-hand side of the screen), in which we focus on both anthropogenic and biogenic fluxes. We run an extensive flux site in Houston since summer 2007 and are busy with data analysis and preparing manuscripts at this time. Graduate student Chang Hyoun Park's PhD thesis revolved around our VOC flux measurements using a new portable REA-GC-dual-FID system. EPA funded us in 2010 to commence research at this site. Graduate students Nick Werner and Marty Hale and undergraduate student Melinda Vargas-Patel work at the tower site or with site data.

We were also funded a new investigator award by NSF in 2010. In that project we will measure leaf physiology and BVOC emissions from oak tree species in the Houston area. Our hypothesis revolves around using the urban climate as a proxy for climate change effects on photosynthsis and isoprene emissions, based on the findings that urban areas - on average - are warmer, exert more water stress, and have higher CO2 concentrations than the surrounding countryside. Undergraduate student Ayrton Bryan, graduate student Jonathan Gramann and postdoctoral researcher Dr. Csengele Barta work on this project.

Contact me if you are interested in any of these two research projects as a student or collaborator.

My main research interests lie in the exchange of trace gases between the biosphere and the atmosphere. Both soils and plants exhange many different trace gases with the atmosphere, and these processes can contribute in different ways to the global biogeochmical cycles of elements such as carbon and nitrogen. Examples are the photosynthetic uptake of carbon dioxide, CO₂, into green plants or the simultaneous reactive deposition of ozone, O₃, into those plants, damaging their photosynthetic apparatus. These two trace gases are also good examples of one that is central to the global carbon cycle but does not directly influence atmospheric chemistry, and one that is central to atmospheric chemistry but does not play a major role in any biogeochemical cycle. If we want to understand the roles these and other trace gases play in biogeochemical cycling and atmospheric chemistry, we need to study their sources, sinks, and transformations in the atmosphere, and their interplay, both in the laboratory and the field. In nature, both the physical and the biological environment can be a major driver of trace gas exchanges. My research involves the detailed study of these processes under current day conditions, the improvement of existing and the development of new models that describe the exchange process(es) as accurately as possible, and the study of physical and chemical feedback mechanisms between the biosphere and the atmosphere. An example for the latter is the partial control of the atmosphere's oxidative capacity by biospheric volatile organic compound (BVOC) emissions, such as isoprene.

We study these BVOC emissions and other exchanges under both laboratory and field conditions. My previous field-based studies included a tower platform in California and a conventionally managed agricultural field plot in Germany. We are using both 'classic' enclosure techniques and several micrometeorological techniques to measure trace gas exchanges between soils, plants, and the atmosphere. For trace gas analysis, we use established infrared or UV absorption analyzers, both gas chromatographic and mass spectrometric techniques, but also specialized systems to target a specific trace gas, such as our past methanol/formaldehyde instrument.

Selected Publications

• C. Park, G.W. Schade, I. Boedeker, Characteristics of the flux of isoprene and its oxidation products in an urban area, Journal of Geophysical Research, in press, 2011

• C. Park, G.W. Schade, I. Boedeker, Flux Measurements of Volatile Organic Compounds by the Relaxed Eddy Accumulation method combined with a GC-FID system north of downtown Houston, Texas, Atmospheric Environment, 44, 2605-2614, 2010

• G. W. Schade, and B. Rappenglück, Unique Meteorological Measurements during hurricane Ike’s passage over Houston, EOS, 90(25), 215-216, 2009

• N.M., Ngwabie, G.W. Schade, T.G. Custer, S. Linke, and T. Hinz,  Abundances and flux estimates of VOCs from a dairy cowshed in Germany, Journal of Environmental Quality, 37, 565-573, 2008
• T. G. Custer and G.W. Schade, Methanol and Acetaldehyde Fluxes Over Ryegrass, Tellus B, 59, 673-684, 2007.
• A. Lee, G.W. Schade, R. Holzinger, and A. H. Goldstein, A comparison of new measurements of total monoterpene flux with improved measurements of speciated monoterpene flux, Atmos. Chem. Phys. 5, 505-513, 2005.
• G. W. Schade and T. G. Custer, OVOC emissions from agricultural soil in northern Germany during the 2003 European heat wave, Atmos. Environ., 38(36), 6105-6114, 2004.
• A. H. Goldstein, M. McKay, M. R. Kurpius, G.W. Schade, A. Lee, R. Holzinger, and R. A. Rasmussen, Forest thinning experiment confirms ozone deposition to forest canopy is dominated by reaction with biogenic VOCs, Geophys. Res. Lett. 31, L22106,  doi:10.1029/2004GL021259, 2004.
• Schade, G.W., and Goldstein, A. H., Increase of monoterpene emissions from a pine plantation as a result of mechanical disturbances, Geophys. Res. Lett. 30(7), doi:10.1029/2002GL016138, 2003.
• Spaulding, R., Schade, G.W., Goldstein, A. H., and Charles, M. J., Characterization of Secondary Atmospheric Photooxidation Products: Evidence for Biogenic and Anthropogenic Sources, J. Geophys. Res., 108(D8), 4247, doi:10.1029/2002JD002478, 2003.
• Dreyfus, G., Schade, G. W., and Goldstein, A. H., Observational Constraints on the Contribution of Isoprene Oxidation to Ozone Production on the Western Slope of the Sierra Nevada, CA, J. Geophys. Res., 107(D19), 4365, DOI:10.1029/2001JD001490, 2002.
• Schade, G.W., and Goldstein, A. H., Fluxes of oxygenated volatile organic compounds from a ponderosa pine plantation, J. Geophys. Res., 106(D3), 3111-3124, 2001.
• Goldstein, A. H., and Schade, G.W., Quantifying biogenic and anthropogenic contributions to acetone mixing ratios in a rural environment, Atmos. Environ., 34 (29-30), 4997-5006, 2000.
• Schade, G.W., Goldstein, A.H., Gray, D.W., and Lerdau, M., Canopy scale and leaf level 2-methyl-3-buten-2-ol fluxes from a ponderosa pine plantation, Atmos. Environ., 34, 3535-3544, 2000.
• Schade, G.W., R. M. Hofmann, and P. J. Crutzen, 1999, CO emissions from degrading plant matter, (I) Measurements, Tellus, 51(5), 889-908, 1999.

Away in 2012

I am on leave in Norway during calendar year 2012. If you are interested in working with me in 2013 or even in Norway in 2012 (I will update contact info and research activities shortly), apply for fall 2012 admission as a graduate student, or e-mail me.