Alex Guenther

General Information

ACD & TIIMES
Senior Scientist
BEACHON

Contact Information:
PO Box 3000, Boulder, CO 80307-3000
Office: FL0-3544
Tel: 303-497-1447
Email: guenther@ucar.edu
Home Page - Vita

Research Focus FY08:

Biosphere-Atmosphere Interactions Group (BAI)

To advance understanding of global biosphere - atmosphere interactions and to predict the response of the earth system to future perturbations. This is being accomplished through multidisciplinary field, laboratory and modeling studies of the processes controlling these interactions on various scales (e.g., leaf to canopy to landscape to global).

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Biosphere-atmosphere Exchange of Aerosols within Cloud, Carbon and Hydrologic cycles, including Organics and Nitrogen (BEACHON)

The BEACHON project conducts experimental and numerical research studies to enhance understanding of the roles of biogenic aerosols, nitrogen trace gases and oxidants in linking and regulating the carbon and water cycles.

Headed up a large BEACHON Retreat, November 2007, whose purpose was to develop a broadly collaborative and interdisciplinary research plan for the new initiatve with an emphasis on connections between the hydrologic cycle and surface-atmophsere fluxes.

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Pine Bark Beetles

When pine bark beetles kill trees, scientists believe they may also alter local weather patterns and air quality. In the News coverage:

- Pine Bark Beetles Affecting More than Forests (NSF)
- Pine bark beetles affecting more than forests (eScienceNews)
- Pine Beetles Changing Rocky Mountain Air Quality, Weather (Environment News Service)
- Pine beetle bite may be leaving mark in air too (Denver Post)
- Study: Beetles affect weather, air quality (Times of the Internet)
- Pine Beetles Changing Rocky Mountain Air Quality, Weather (Mountain Pine Beetle)
- Pine Beetles Changing Rocky Mountain Air Quality, Weather (The Westerner)
- Study looks at beetles' effects on weather (USA Today)

 

Plants Make Their Own Painkillers

Walnut trees respond to stress by producing significant amounts of a chemical form of aspirin, scientists have discovered: Thomas Karl, Alex Guenther, Andrew Turnipseed, Edward Patton, & Kolby Jardine. In the News:

- Walnut Trees Emit Aspirin-Like Chemical to Deal With Stress (NSF)
- Plants Make Own Painkillers (LiveScience)
- Plants make their own version of aspirin, researchers find (Los Angeles Times)
- Stressed plants release aspirin-like chemical (Reuters)
- Stressed plants produce an aspirin-like chemical (What is life science)
- Stressed plants produce Aspirin (Medical & Pharmacy News)
- Mother Nature’s little helper (nature.com)

 

Field Programs FY08:

BEACHON - Southern Rocky Mountains Summer 2008 Study (BEACHON-SRM08)
July - September 2008, Woodland Park, Colorado

SRM08 is the initial research phase in the four year BEACHON research program in water-limited Western U.S. pin forest ecosystems that will improve the understanding of fundamental biogeochemical processes that are central to achieving the objectives of the BEACHON research program. BEACHON-SRM08 is considered a pre-study in advance of long-term measurements of key atmospheric and ecosystem parameters at the same site as well as a more comprehensive regional campaign in 2010. Because of this, the study has practical objectives relating to the setup and operation of the MEF site in addition to specific scientific foci on atmospheric chemistry and aerosol processes.

The field study took place at the Manitou Experimental Forest (MEF) from 21 July – 19 September 2008. Several specific scientific objectives will be addressed during this pre-study, listed below.

• The formation and growth of atmospheric nanoparticles: The goals are to understand and quantify the formation of new particles and to determine the mechanism by which these particles grow to become important participants in atmospheric chemistry and climate.

• Emissions and reactions of Biogenic Volatile Organic Compounds (BVOCs) and other important trace gases and oxidants: These measurements are designed to reduce uncertainties of the concentrations and fluxes of important trace gases, including BVOCs and primary oxidants such as O3, NO3, OH, and HO2/RO2.

• The formation and hygroscopic properties of biogenic Secondary Organic Aerosols (SOA) and primary particles.

• Terrestrial and canopy controls on the emission and deposition of water, nutrients and aerosols: Several measurements focusing on processes relevant to the biology and hydrology of this ecosystem will start during the campaign. These are expected to develop into a more comprehensive suite of measurements over time.

• Characterize transport in canopy and from canopy to cloud: One unique aspect of the current study is the exploration of the use of ground-based remote sensing for obtaining insights into the transport of trace gases and aerosols from canopy to cloud.

• BEACHON Modeling of Aerosol-Cloud-Emissions Interactions: Two 3-dimensional models, the Large Eddy Simulation (NCAR LES) coupled with chemistry and WRF-Chem, will be used to investigate interactions between biogenic emissions, atmospheric oxidants, aerosols, and clouds. Both of these models will simulate representative conditions of those sampled in the field. Initially cases will focus on the Manitou Experimental Forest field site in the Colorado Rockies. To conduct these simulations, both measurements for initializing and evaluating the models and model development are needed.

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Amazon Aerosol Characterization Experiment (AMAZE-08)
January - March 2008, Manaus, Brazil

The main objectives of AMAZE-08 are to understand the sources and regulators of organic particle mass in a pristine continental environment and the connections between particle chemistry and particle optical and hygroscopic properties.

The AMAZE-08 tower measurements were conducted between February 7 and March 14, 2008 during the rainy reason. The site was 60 km NNW of Manaus and located within a mostly pristine rainforest. The winds were predominantly from the ENE across 1600 km of untouched forest. Except for episodes of long-range transport from Europe and Africa and infrequent transport from Manaus, the site was free of anthropogenic influences and allowed the study of pristine biological aerosol particles.

Particle instrumentation included two high-resolution aerosol mass spectrometers (HR-ToF-AMS) with thermodenuder, two cloud condensation nuclei counters (CCNC), a continuous flow diffusion chamber (CFDC) for ice nuclei measurements, three optical particle counters (OPC), an ultraviolet aerodynamic particle sizer (UV-APS) for measurement of biologically active particles, two tapered element oscillating microbalances (TEOM), two scanning mobility particle sizers (SMPS), two multiwavelength nephelometers, three condensation particle counters (CPC) a multi-angle absorption photometer (MAAP), an athelometer, coarse- and fine-mode filters for elemental and ion analysis, an AErosol RObotic NETwork (AERONET - NASA) sunphotometer including photosynthetically active radiation (PAR), and LIDAR system. Gas instrumentation included a proton-transfer mass spectrometer (PTR-MS), gas adsorption cartridge for off-line chromatographic analysis, and measurement of O3, CO, CO2, NO, and NOx.

Community Service FY08:

• Editorial Board: Atmospheric Chemistry and Physics
• Editorial Board: Atmospheric Environment
• Co-Chair: International Geosphere Biosphere Program (IGBP) – Analysis and Integration of Models of the Earth System (AIMES) – Global Emissions Inventory Activity (GEIA)
• Graduate Research Advisor & Thesis/Dissertation Committee: Kolby Jardine (SUNY Stonybrook, NY)
• Graduate Research Advisor & Thesis/Dissertation Committee: Monica Madronich (CU)
• Thesis/Dissertation Committee: Xiaoyan Jiang (PhD University of Texas)
• Thesis/Dissertation Committee: Tanarit Sakulyanontvittaya (PhD CU)

Scientific Presentations FY08:

• The Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics & Nitrogen (BEACHON) project: First results and future plans (New Orleans, LA)
• What are the right precursors to SOA? (Manaus, Brazil)
• Surface-Atmosphere Exchange Measurements:Alternatives to Eddy Covariance (Pellston, MI)
• Biogenic trace gases and SOA (Reykjavik, Iceland)
• The changing earth system (Kota Kinabalu, Malaysia)
• Identifying and Describing the Processes Controlling Biogenic VOC Emissions (Helsingborg, Sweden)
• Sources and Sinks of Atmospheric Compounds:Biogenic Volatile Organic Compound Emissions (Wageningen, Netherlands)
• The Role of Biogenic VOC Emissions in the Earth System (Pullman, WA)

Publications FY08:

Boy, M., T. Karl, A. Turnipseed, R. L. Mauldin, E. Kosciuch, J. Greenberg, J. Rathbone, J. Smith, A. Held, K. Barsanti, B. Wehner, S. Bauer, A. Wiedensohler, B. Bonn, M. Kulmala, A. Guenther, 2008: New particle formation in the Front Range of the Colorado Rocky Mountains. Atmos. Chem. Phys., 8, 1577-1590.

Duhl, T. R., D. Helmig, A. B. Guenther, 2008: Sesquiterpene emissions from vegetation: a review. Biogeosciences, 5, 761-777
Guenther, A. B., 2008: Are plant emissions green? Nature, 452, 701-702.

Heald, C. L., D. K. Henze, L. W. Horowitz, J. Feddema, J.-F. Lamarque, A. Guenther, P. G. Hess, F. Vitt, J. H. Seinfeld, A. H. Goldstein, I. Fung, 2008: Predicted change in global secondary organic aerosol concentrations in response to future climate, emissions, and land-use change. J. Geophys. Res., 113, D05211, doi: 10.1029/2007JD009092.

Jardine, K., P. Harley, T. Karl, A. B. Guenther, M. Lerdau, J. E. Mak, 2008: Plant physiological and environmental controls over the exchange of acetaldehyde between forest canopies and the atmosphere. Biogeosciences. (Submitted)

Karl, T., A. B. Guenther, A. A. Turnipseed, E. G. Patton, K. Jardine, 2008: Chemical sensing of plant stress at the ecosystem scale. Biogeosciences Discuss., 5, 2381-2399.

Matsunaga, S. N., A. B. Guenther, M. J. Potosnak, E. C. Apel, 2008: Emission of sunscreen salicylic esters from desert vegetation and their contribution to aerosol formation. Atmos. Chem. Phys.. (Submitted)

Megonigal, J. P., A. B. Guenther, 2008: Methane emissions from upland forest soils and vegetation. Tree Physiology, 28, 491-498.

Millet, D. B., D. J. Jacob, K. F. Boersma, T.-M. Fu, T. P. Kurosu, K. Chance, C. L. Heald, A. Guenther, 2008: Spatial distribution of isoprene emissions from North America derived from formaldehyde column measurements by th OMI satellite sensor. J. Geophys. Res., 113, D02307.

Muller, J.-F., T. Stavrakou, S. Wallens, I. De Smedt, M. Van Roozendael, M. J. Potosnak, J. Rinne, B. Munger, A. Goldstein, A. B. Guenther, 2008: Global isoprene emissions estimated using MEGAN, ECMWF analyses and a detailed canopy environment model. Atmos. Chem. Phys., 8, 1329-1341.

Nemitz, E., J. L. Jimenez, J. A. Huffman, I. M. Ulbrich, M. R. Canagaratna, D. R. Worsnop, A. B. Guenther, 2008: An eddy-covariance system for the measurement of surface/atmosphere exchange fluxes of submicron aerosol chemical species - first application above an urban area. Aerosol Science and Technology, 42, 636-657, doi: 10.1080/02786820802227352.

Ortega, J., D. Helmig, R. W. Daly, D. M. Tanner, A. B. Guenther, J. D. Herrick, 2008: Approaches for quantifying reactive and low-volatility biogenic organic compound emissions by vegetation enclosure techniques - Part B: Applications. Chemosphere, 72, 365-380, doi: 10.1016/j.chemosphere.2008.02.054.

Patton, E. G., T. Horst, D. H. Lenschow, P. P. Sullivan, S. P. Oncley, S. P. Burns, A. B. Guenther, T. Karl, S. D. Mayor, S. M. Spuler, J. Sun, A. A. Turnipseed, E. Allwine, S. Edburg, B. Lamb, R. Avissar, H. Holder, R. Calhoun, J. Kleissl, W. Massman, K. Tha Paw U, J. Weil, L. Rizzo, A. Held, 2008: The Canopy Horizontal Array Turbulence Study (CHATS). , Stockholm, SE, AMS, American Meteorological Society, 18A.1.

Pfister, G. G., L. K. Emmons, P. G. Hess, J.-F. Lamarque, J. J. Orlando, S. Walters, A. Guenther, P. I. Palmer, P. J. Lawrence, 2008: Contribution of isoprene to chemical budgets: A model tracer study with the NCAR CTM MOZART-4. J. Geophys. Res., 113, D05308, doi: 10.1029/2007JD008948.

Sakulyanontvittaya, T., T. Duhl, C. Wiedinmyer, D. Helmig, S. Matsunaga, M. Potosnak, J. Milford, A. Guenther, 2008: Monoterpene and Sesquiterpene Emission Estimates for the United States. Environ. Sci. Technol., 42, 1623-1629.

Sparks, J. P., J. T. Walker, A. A. Turnipseed, A. B. Guenther, 2008: Dry Nitrogen deposition estimates over a forest experiencing free air CO2 enrichment. Global Change Biology, 14, 768-781, doi: 10.1111/j.1365-2486.2007.01526.x.

Yokelson, R. J., T. Christian, T. Karl, A. B. Guenther, 2008: The tropical forest and fire emissions experiment: laboratory fire measurements and synthesis of campaign data. Atmos. Chem. Phys., 8, 3509-3527.