The data sets
ozone.median
,
ozone.quartile
,
ozone.city
, and
ozone.xy
contain data on ozone concentrations in 41 U.S. cities.
x
and
y
that give the negative longitude and latitude of the monitoring sites, respectively, as measured in the coordinate system used by the
usa
function.
Cleveland, W.S., Kleiner, B., McRae, J.E., Warner, J.L., and Pasceri, P.E. (1975). The Analysis of Ground-Level Ozone Data from New Jersey, New York, Connecticut, and Massachusetts: Data Quality Assessment and Temporal and Geographical Properties. Bell Laboratories Memorandum.
The original data were collected by the New Jersey Department of Environmental Protection, the New York State Department of Environmental Protection, the Boyce Thompson Institute (Yonkers, for New York data), the Connecticut Department of Environmental Protection, and the Massachusetts Department of Public Health.