The department conducts air chemistry research in regional air quality, the atmospheric effects of aircraft, and chemistry's role in global change. These efforts involve developing state-of-the-art sensors for reactive trace gases, field observations using these sensors, and analysis with computer models of atmospheric chemistry and dynamics. These sensors and sensors for other gases, micrometeorology, and radiation are being used to study the interaction of chemistry and dynamics in the planetary boundary layer and the remote troposphere.
In-situ measurements of turbulence, micrometeorological, air pollution and acidic deposition variables are performed routinely at the Larson Agricultural Research Center Farm and the Scotia Atmospheric Chemistry site. The acidic precipitation data, which have been gathered since 1976 at the Scotia site, provide one of the longest records in the country. Research and development groups from several national and international laboratories come to these field sites for calibrating and checking the performance of their diverse measurement systems. In addition, various aspects of cloud physics and chemistry are investigated in the laboratory to help interpret these field measurements.
The laboratory proves to be an ideal place in which to investigate some of the important microscale phenomena that contribute to the formation and properties of clouds and aerosols. The Department's 1400-ft2 laboratory space is well equipped with pure water and air facilities, fume hoods, a clean bench, sample refrigerator, several freezers, and a high-capacity vacuum line. As needed, additional equipment is developed and used to conduct specific experiments, such as those designed to study the growth of cirrus-like ice crystals, to investigate the nucleating capabilities of aerosol particles, to measure the rates with which aerosol particles and trace gases are taken up by snow, and to explore the interactions of ambient moisture and nitric acid vapor with representative aerosol particles. The results from the laboratory experimentation find application in a variety of physical and chemical models of atmospheric clouds and aerosols.
Penn State faculty (S. Richardson, N. Miles, and K. Davis) maintain a calibration lab and field equipment capable of measuring concentrations of carbon dioxide and methane with very high accuracy and precision, and have deployed measurement systems for multiple field campaigns including the NACP Midcontinent Intensive, the Indianapolis Flux Experiment, the Marcellus shale gas study, the Gulf Coast intensive and ACT-America. We routinely contribute our observations to NOAA Global Monitoring Division's collection of well-calibrated greenhouse gas measurements, and participate in NOAA round-robin comparisons of lab calibration standards for greenhouse gas measurements. We also maintain and deploy eddy covariance flux measurements which quantify ecosystem-atmosphere fluxes of greenhouse gases, water vapor, sensible heat and momentum, and have deployed these systems over forests, cities and agricultural sites.
The ASOS system monitors meteorological variables such as wind speed and direction, barometric pressure, temperature and dewpoint, accumulated precipitation, precipitation type and the height of the cloud base. Lightning and freezing rain sensors are also included.