Engineering topics
Publications and source records attributed to Enekwizu, Ogochukwu.
The U.S. Department of Energy’s Atmospheric Radiation Measurement user facility (ARM) deploys at each of ARM’s observatories a suite of aerosol and trace gas (further mention of aerosols will assume inclusion of trace gases) instrumentation that constitute the Aerosol Observing Systems (AOS; Uin et al. 2019).
The Cloud Condensation Nuclei Counter—CCN (Figure 1) is a U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility instrument for measuring the concentration of aerosol particles that can act as cloud condensation nuclei [1, 2]. The CCN draws the sample aerosol through a column with thermodynamically unstable supersaturated water vapor that can condense onto aerosol particles. Particles that are activated, i.e., grown larger in this process, are counted (and sized) by an Optical Particle Counter (OPC). Thus, activated ambient aerosol particle number concentration as a function of supersaturation is measured. Models CCN-100 and CCN-200 differ only in the number of humidifier columns and related subsystems: CCN-100 has one column and CCN-200 has two columns along with dual flow systems and electronics.
Aerosol Observing System (AOS) CCN200 data stream