pollution {ExtremalDep}

Air quality datasets containing daily maxima of air pollutants (PM10, NO, NO2, 03 and S02) recorded in Leeds (U.K.), during five winter seasons (November-Februrary) between 1994 and 1998.

Description

Contains 6 datasets: PNS, PNN, NSN, PNNS, winterdat and Leeds.frechet.

Details

The dataset winterdat contains 590 (transformed) observations for each of the five pollutants. Contains NAs. Outliers have been removed according to Heffernan and Tawn (2004). The following datasets have been obtained by applying transformations to winterdat.

Leeds.frechet contains 590 observations corresponding to the daily maxima of five air pollutants transformed to unit Frechet scale.

NSN contains 100 observations in the 3-dimensional unit simplex for the daily maxima of nitrogen dioxide (NO2), sulfur dioxide (SO2) and nitrogen oxide (NO).

PNN contains 100 observations in the 3-dimensional unit simplex for the daily maxima of particulate matter (PM10), nitrogen oxide (NO) and nitrogen dioxide (NO2).

PNS contains 100 observations in the 3-dimensional unit simplex for the daily maxima of particulate matter (PM10), nitrogen oxide (NO) and sulfur dioxide (SO2).

PNNS contains 100 observations in the 4-dimensional unit simplex for the daily maxima of particulate matter (PM10), nitrogen oxide (NO), nitrogen dioxide (NO2) and sulfur dioxide (S02).

The transformation to unit Frechet margins of the raw data has been considered by Cooley et al (2010). Only the 100 data points with the largest radial components were kept.

Source

https://uk-air.defra.gov.uk/

References

Cooley, D.,Davis, R. A., and Naveau, P. (2010). The pairwise beta distribution: a flexible parametric multivariate model for extremes. Journal of Multivariate Analysis, 101, 2103–2117.

Heffernan, J. E., and Tawn, J. A. (2004). A conditional approach for multivariate extreme values. Journal of the Royal Statistical Society, Series B, Methodology, 66, 497–546