Multi-wavelength analysis of particle light absorption

This project is no longer running.

AQRC scientists have designed and built a new broad-band light source instrument to adapt the Hybrid Integrating Plate/Sphere Analysis (HIPS) light absorption measurement for a full spectrum of wavelengths throughout the visible and including the near IR and UV. Work is underway to develop approaches for calibration and for analysis of the data from this new spectrometer.

Evaluation of organic carbon measurements in the IMPROVE and CSN networks

The gain and loss of gaseous carbonaceous material from quartz filters can bias the measurement of organic particulate matter. The Air Quality Research Lab scientists have worked with others in the IMPROVE and Chemical Speciation Network (CSN) communities to investigate organic carbon measurement uncertainty related to determining a consistent method for estimating sampling artifacts and evaluating post-sampling losses during field latency and transport

Contact—Ann Dillner (530-752-0509)

FT-IR OM, OC, EC and functional groups

The Air Quality Research Center is conducting an ongoing research program to develop FT-IR (Fourier transform-infrared spectroscopy) methods to measure functional groups, organic matter (OM), organic carbon (OC) and elemental carbon (EC) in particles collected on Teflon© filters.  Direct measurement of OM is useful because current methods require using an estimated organic mass/organic carbon ratio—OM/OC—to convert measured OC to OM.

Characterization of IMPROVE data quality

Each year the Air Quality Research Center delivers nearly one million new measurement values for the IMPROVE network. A large community of researchers and analysts use these data to address a wide range of scientific and regulatory issues. All data pass through multiple layers of review and quality assurance before publication, but all carry some uncertainty from the irreducible error that is present in any measurement. An ongoing program of research works to:


Chemical Speciation Network

CSN is the Chemical Speciation Network for the EPA. It is a PM2.5 sampling network with sites located principally in urban areas. The AQRC manages the data produced from CSN. The data first goes through a data ingest process that is completed by AQRC data management staff who have advanced training in database programming and database management.  Then an AQRC data analyst will process the sampling and analytical data. The data analyst will use functions in our custom software package to calculate final results and post them to the CSN database.