This dataset corresponds to observations at PROPHET in July 2014, as described in Gunsch et al. 2018, Atmospheric Chemistry & Physics.
Long-range aerosol transport affects locations hundreds of kilometers from the point of emission, leading to distant particle sources influencing rural environments that have few major local sources. Source apportionment was 5 conducted using real-time aerosol chemistry measurements made in July 2014 at the forested University of Michigan Biological Station near Pellston, Michigan, a site representative of the remote forested Great Lakes region. Size-resolved chemical composition of individual 0.5–2.0 µm particles was 10 measured using an aerosol time-of-flight mass spectrometer (ATOFMS), and non-refractory aerosol mass less than 1 µm (PM1) was measured with a high-resolution aerosol mass spectrometer (HR-AMS). The field site was influenced by air masses transporting Canadian wildfire emissions and ur15 ban pollution from Milwaukee and Chicago.
Atmospheric trace gas and particulate matter chemistry were measured at PROPHET in July 2014 to improve our understanding of aerosol source contributions in the upper midwest US.
Air was sampled from 34 m a.g.l.
TSI model 3800 aerosol time-of-flight mass spectrometer (ATOFMS); Aerodyne high-resolution aerosol mass spectrometer; TSI model 3936 scanning mobility particle sizer; TSI model 3321 aerodynamic particle sizer; Thermo Scientific model 49 ozone analyzer
Measurements of ozone, sensible heat, and latent heat fluxes and plant physiological parameters were made at a northern mixed hardwood forest located at the University of Michigan Biological Station in northern Michigan from June 27 to September 28, 2002. These measurements were used to calculate total ozone flux and partitioning between stomatal and non-stomatal sinks. Total ozone flux varied diurnally with maximum values reaching 100 8mol m-2 h-1 at midday and minimums at or near zero at night. Mean daytime canopy conductance was 0.5 mol m-2 s-1. During daytime, non-stomatal ozone conductance accounted for as much as 66% of canopy conductance, with the non-stomatal sink representing 63% of the ozone flux. Stomatal conductance showed expected patterns of behaviour with respect to photosynthetic photon flux density (PPFD) and vapour pressure defecit (VPD). Non-stomatal conductance for ozone increased monotonically with increasing PPFD, increased with temperature (T) before falling off again at high T, and behaved similarly for VPD. Day-time non-stomatal ozone sinks are large and vary with time and environmental drivers, particularly PPFD and T. This information is crucial to deriving mechanistic models that can simulate ozone uptake by different vegetation types.
These measurements and post processing were repeated in 2003, 2004, and 2005 at varying time intervals.
Above-canopy fluxes of ozone were measured from the 35 m PROPHET tower. The ozone sample inlet and sonic anemometer were located 33 m above ground and the air sample was transported to the detector via a 40 m length of 5/8-in. Teflon tubing. The residence time from sample inlet to the detector in the laboratory at the base of the tower was typically less than 25 s. Wind speed and direction (Wind Monitor-RE, R. M. Young Company, USA), pressure (Barometric Pressure Sensor Model 61201, R. M. Young Company, USA), temperature and relative humidity (MP100, Rotronics Instrument Corp, USA) are measured continuously at the top of the PROPHET tower (Carroll et al., 2001). An open-path infrared gas analyzer (IRGA) (Auble and Meyers, 1992) was co-located with the sonic anemometer (K- configuration, ATI, USA) to measure water and CO2 concentration (Pressley et al., 2005). Photosynthetic photon flux density (PPFD) (LI-190SZ, Li-Cor, USA) was measured on the adjacent Ameriflux tower (Schmid et al., 2003), which is located 132 m north–northeast of the PROPHET tower.
Ozone was measured using the University of Michigan Multichannel Chemiluminescence Instrument (UMMCI), a custom-built chemiluminescence detector (e.g. Ridley, et al., 1992), illustrated in Fig. 1. The detector consists of a gold-plated 316 stainless-steel reaction vessel (RV, 17 cm3, maintained at 35 degrees C, design by B. A. Ridley, Ridley, et al., 1992), a red-sensitive Hamamatsu R1333 photomultiplier tube (PMT, operated at 5 degrees C), and zeroing volume (ZV, maintained at 100 degrees C) containing 0.5% Pd on Al ozone destruction catalyst (Degussa Metals Corp.).
Data collected on Campbell Scientific CR23X micrologger.
Air Temperature and Relative humidity measured with Rotronic HPO-43 Probe
Net Radiation measured with a REBS Q*7 net radiometer
PAR measured with LI-COR LI-190 quantum sensor
Short wave radiation measured with LI-COR LI-200 pyranometer
Rainfall measured with Texas Electronics TE525MM tipping bucket rain gauge
Isoprene concentration and flux were measured at the University of Michigan Biological Station (UMBS) PROPHET and AmeriFlux towers in a mixed northern hardwood forest in 2000-2003. The isoprene concentration profiles sampling heights in 2000 were: 3.5, 7, 11, 14, 22, 31, and 46 meters above ground level. The isoprene concentration profiles sampling heights in 2001 were: 3.5, 7, 14, 17, and 31. The isoprere flux sampling height was 31 meters above ground level in 2000 and 2001.
Isoprene samples were collected over a 30-minute period into the stainless steel canisters and analyzed using GC/FID. Midpoints of the 30-minute periods were 15 minutes and 45 minutes after each hour. All temperature and photosynthetic photon flux density (PPFD)data were collected on the AmeriFlux tower (2000 only).
The AmeriFlux Data were time averaged using the following techniques:
Temperature: For the 4 and 15 m samples, temperature is the average of 30 samples for the half hour period. Each sample is a 1 minute average of 0.5 Hz sampling. For the 21, 34, and 46 m heights, temperature is the average of 3 samples collected every 10 minutes within the half hour period. Each of the 3 samples is an average over 10 minutes at 0.5 Hz frequency.
PPFD: The PPFD samples are averages of 3 samples collected every 10 minutes within the half hour period. Each of the 3 samples is an average over 10 minutes at 0.5 Hz frequency.
NOTE: In the data file "WSU_Isoprene_Profiles_v1.csv", PPFD is denoted as PAR (Photosynthetically Active Radiation).
Missing data are indicated by –999 and values below the detection limit are indicated by –777
Detection limits: isoprene 0.3 ppbv
Instrument precision 5%
Total uncertainty: 10%
All flux data reported are from the AmeriFlux Tower at 31 m above ground level. Data was collected at 10 Hz and averaged over 30 minute periods. Midpoints of the 30-minute periods are 15 minutes and 45 minutes after each hour. Periods missing more than 15 minutes of data were eliminated. Rainy periods were deleted due to problems with both the sonic anemometer and the IRGA.
Missing data are indicated by –999 and values below the detection limit indicated by –888.
NOTE: Isoprene Flux data and Isoprene mixing ratio data are subject to filtering for various applications. The data posted here have not been filtered, so please contact WSU for guidance if you plan on using either data set.
Hills Scientific Fast Isoprene Sensor, model FIS-97, with associated ClearWater Tech., L.L.C. Ozone Generator
Open Path Infrared Gas Analyzer (IRGA) developed at the Atmospheric Turbulence and Diffusion Division, NOAA
Applied Technologies, Inc. 3-D sonic anemometer/thermometer model #SATI/3K
KNF sampling pumps
6-liter stainless steel canisters
Gas Chromatography with Flame Ionization Detection
Rotronic RH/temperature sensor
PPFD Quantum sensor
KBK and Pressley QC
These files came off of the PROPHET archive, here is the mapping of file names:
Research Gateway -> PROPHET Archive
Isoprene_flux_2000_v[x].csv -> Prophet_archive_6_03.txt
Isoprene_flux_2001_v[x].csv -> blis2a07.p01.txt