DANIEL OBRIST

Assistant Research Professor
Division of Atmospheric Sciences

Resume

PROFESSIONAL INTERESTS:

My research interests include quantification of exchange processes of pollutants and other atmospheric species between soils, plants, and the atmosphere, with an emphasis on how human activities (e.g., anthropogenic emissions, global change) affect these processes. Current research projects focus on the biogeochemical cycling of mercury in soils and the environment, the importance of long-range transport of atmospheric pollutants (e.g., Asian pollution events) for the Western United States, and development of optical sensors to measure atmospheric pollutants. Past research projects included the study of effects of large wildfires and global change (e.g., elevated CO₂, increasing tropospheric ozone) on hydrologic processes and carbon/nutrient cycling in arid and alpine ecosystems. An important focus of my research has always been the development and application of new techniques to measure exchange fluxes at the level of whole ecosystems. Such methods include large static chambers, gradient-based micrometeorological methods, and atmospheric measurements in stable nocturnal boundary layers to quantify large-scale emission and deposition processes.

RECENT PROJECTS:

• Asian long-range transport of atmospheric mercury measured at DRI's Storm Peak Laboratory in Steamboat Springs, Colorado.
• Effects of global change on the atmospheric mercury burden and mercury sequestration through changes in ecosystem carbon pools.
• Quantification of elemental Hg exchange using ²²²Rn/Hg accumulation in the stable nocturnal boundary layer.
• Mercury fluxes and reductive processes in alpine soils.
• Effects of global change and wildfires on ecosystem hydrology and carbon cycling.

SELECTED PUBLICATIONS:

Fritsche J, Wohlfahrt G, Ammann C, Zeeman MJ, Obrist D, Alewell C. (2008).

Summertime elemental mercury exchange of temperate grasslands on an ecosystem-scale.  Atmospheric Chemistry and Physics Discussions, Atmos. Chem. Phys. Discuss., 8, 1951-1979, (published online).

Fritsche J, Obrist D, Zeeman MJ, Conen F, Eugster W, Alewell C. (2008).

Elemental mercury fluxes over a sub-alpine grassland in Switzerland determined with two micrometeorological methods. Atmospheric Environment, 42, 2922-2933.

Fritsche J, Obrist D, Alewell C. (2008).

Effects of microbiological activity on Hg0 emission in uncontaminated terrestrial soils.  Plant Nutrition and Soil Science, 171, 200-209

Obrist D, Moosmüller H, Schürmann R, Chen A, Kreidenweis S. (2008).

Particulate-phase and gaseous elemental mercury emissions during biomass combustion: controlling factors and correlation with particulate matter emissions. Enviromental Science and Techology, 42, 721-727.

Li W, Collins JF, Durbin TD, Huai T, Ayala A, Full G, Mazzoleni C, Nussbaum NJ, Obrist D, Zhu D, Kuhns HD, Moosmüller H (2007). 

Detection of Gasoline Vehicles with Gross PM Emissions. SAE Tech. Pap. Ser., SP-2089, 2007-01-1113.

Peleg M, Matveev V, Tas E, Luria M, Valente RJ, Obrist D (2007).

Mercury depletion events in the troposphere in Mid-Latitudes at the Dead Sea, Israel. Environmental Science and Technology, 41, 7280-7285

Faïn X, Grangeon S, Bahlmann E, Fritsche J, Obrist D, Dommergue A, Ferrari CP, Cairns W, Ebinghaus R, Barbante C, Cescon P, Boutron C. (2007).

Diurnal production of Gaseous Mercury in the alpine snowpack before snowmelt. Journal of Geophysical Research – Atmosphere, 112, D21311.

Obrist D (2007).

Atmospheric mercury pollution due to losses of carbon pools? Biogeochemistry 85, 119-123.

Millhollen AG, Gustin MS, Obrist D (2006).

Foliar mercury accumulation and exchange for three tree species.  Environmental Science and Technology, 40, 6001-6006.

Millhollen AG, Obrist D, Gustin MS (2006). 

Mercury accumulation in grass and forb species as a function of atmospheric carbon dioxide concentrations and mercury.  Chemosphere, 65, 889-897.

Obrist D, Conen F, Vogt R, Siegwolf R, Alewell C (2006). 

Quantification of elemental Hg0 exchange using 222Rn/Hg0 accumulation in the stable nocturnal boundary layer.  Atmospheric Environment, 40, 856-866.

Prater MR, Obrist D, Arnone JA, DeLucia EH.  (2006).

Net carbon exchange and evapotranspiration in postfire and intact sagebrush communities in the Great Basin.  Oecologia, 146, 595-607.

Obrist D, Gustin MS, Arnone JA, Schorran DE, Verburg PSJ, Johnson DW (2005).

Measurements of gaseous elemental mercury fluxes over intact tallgrass prairie monoliths during one full year.  Atmospheric Environment, 39, 957-965.

Obrist D, Yakir, D, Arnone JA III (2004). 

Temporal and spatial patterns of soil water following wildfire-induced changes in plant communities in the Great Basin.  Plant and Soil, 262, 1-12.

Verburg PS, Arnone JA, Obrist D, Schorran DE, Evans D, LeRoux-Swarthout D, Johnson D, Luo Y, Coleman JS (2004). 

Net ecosystem carbon exchange in two experimental grassland ecosystems.  Global Change Biology, 10, 498-508.

Obrist D, Verburg PSJ, Young MH, Coleman JS, Schorran DE, Arnone JA (2003).

Quantifying the effects of phenology on ecosystem evapotranspiration in planted grassland mesocosms using EcoCELL technology.  Agricultural and Forest Meteorology, 118,173-183.

Obrist D, DeLucia EH, Arnone JA (2003).

Consequences of wildfire on ecosystem CO2 and water vapor fluxes in the Great Basin. Global Change Biology, 9, 563-574.

Arnone JA, Obrist D (2003).

A large daylight geodesic dome for quantification of whole ecosystem CO2 and water vapor fluxes in arid ecosystems. Journal of Arid Environments, 55, 629-643.

Obrist D, Arnone JA (2003).

Root development, soil water use, and root proliferation into resource-rich soil patches of Larrea tridentata under past, ambient, and future atmospheric CO2 levels.  New Phytologist, 159, 175-184.

Obrist D, Arnone JA, Körner Ch (2001).

In situ effects of elevated atmospheric CO2 on leaf freezing resistance and carbohydrates in a native temperate grassland. Annals of Botany, 87(6), 839-844.