Atmospheric CO₂at Brookhaven, Long Island, New York: Patterns of variation up to 125 meters

Intermittent observations of CO2 concentrations over 6 years at heights up to 125 meters show that the CO2 content of air is extremely variable but that diurnal, seasonal, and annual patterns are conspicuous. The usual diurnal pattern shows largest variation close to the ground. Highest concentrations occur during nocturnal temperature inversions. As might be expected on Long Island, westerly winds tend to have higher CO2 contents than easterly winds. The normal seasonal fluctuation is from a high in December and January to a low in September. The difference is about 19 ppm. There is a year-to-year increase in CO2 content of air that averaged 1.2 ppm/yr over the 6-year span of the study. Although the variance of CO2 measurements is high within the industrialized area of eastern North America, there is a reasonable possibility of examining trends in CO2 content of air by sufficiently intensive measurements.