Reference
Idso, C.D., Idso, S.B., Idso, K.E., Brooks, T. and Balling, R.C. 1998. Spatial and temporal characteristics of the urban CO2 dome over Phoenix, Arizona. Preprint volume of the 23rd Conference on Agricultural & Forest Meteorology, 13th Conference on Biometeorology and Aerobiology, and 2nd Urban Environment Symposium, pp. 46-48. American Meteorological Society, Boston, MA.
What was done
In an earlier study it was found that wintertime near-surface atmospheric carbon dioxide concentrations throughout the Phoenix metropolitan area were elevated by as much as 50% above the surrounding rural mean of 370 ppm. The authors of this paper repeated that wintertime study during the hottest period of the year in an effort to determine whether or not the winter relationship between urban and rural near-surface atmospheric CO2 concentrations was any different in the summer.
What was learned
Although maximum and minimum daily air temperatures were 24°C warmer, and wind speeds nearly two times greater than they were in the winter, near-surface atmospheric CO2 concentrations varied but little between these two times of year.
What it means
The data indicate that "the magnitude and extent of the urban CO2 dome over the Phoenix metropolitan area may be largely independent of mean climatic conditions." The authors thus suggest that the presence of the classical urban heat island and this rather stable region of enhanced CO2 concentrations "could prove useful in investigating potential impacts of the increased global temperatures and CO2 concentrations that are being predicted for the future, especially with respect to earth's plant life."
Reviewed 1 February 1999