The Barrow, Alaska Automatic Condensation Nuclei Counter and Four Wavelength Nephelometer: Instrument Details and Four Years of Observations

摘要

NOAA's Geophysical Monitoring for Climatic Change program operates a background monitoring station at Barrow, Alaska. Aerosol monitoring at Barrow was initiated in May 1976 with an automatic condensation nuclei counter, Pollak nuclei counter, and four wave-length nephelometer. These instruments provide a continuous aerosol climatology and identify periods of contamination. The G.E. counter data were calibrated from the G.E. Pollak data-pairs generated from the raw one-minute G.E. counter voltages. A linear least squares analysis was used to determine a best fit regression for 1976 data with the Pollak data as th independent variable and a multiplicative scaling factor for 1977 through 1979 generated from a histogram of G.E.-Pollak data ratios. Light scattering data show an annual cycle. Condensation nuclei data show a semiannual change with monthly mean concentrations ranging between 50/CC and 1000/CC. Maxima are present in March and August, minima in June and September. The continuously operating four wavelength nephelometer and G.E. condensation nuclei counter in conjunction with a Pollak nuclei counter, have produced an excellent data set over the four year period, 1976-1979.