SCHEDULE 8INFORMATION TO BE OBTAINED AND COLLATED ON OZONE LEVELS, AND CRITERIA FOR AGGREGATING DATA AND CALCULATING STATISTICAL PARAMETERS

PART IICriteria for aggregating data and calculating statistical parameters

In this Part, percentiles are to be calculated using the method specified in Council Directive 97/101/EC12.

The following criteria are to be used for checking validity when aggregating data and calculating statistical parameters:

Parameter

Required proportion of valid data

1 hour values

75% (45 minutes)

8 hour values

75% of values (6 hours)

Maximum daily 8 hours mean from hourly running 8 hours averages

75% of the hourly running 8 hour averages (8 hours per day)

AOT40

90% of the 1 hour values over the time period defined for calculating the AOT40 (a)

Annual mean

75% of the 1 hour values over summer (April to September) and winter (January to March, October to December) seasons separately

Number of exceedances and maximum values per month

90% of the daily maximum 8 hours mean value (27 available daily values per month) 90% of the 1 hour values between 8:00 and 20:00 Central European Time

Number of exceedances and maximum values per year

Five out of six summer months over the summer season (April to September)

(a)

in cases where all possible measured data are not available, the following factor must be used to calculate AOT40 values:

AOT40(estimate)=AOT40(measured)×totalpossiblenumberofhours*number of measured hourly valuesmath

*being the number of hours within the time period of AOT40 definition (that is, 8:00 to 20:00 Central European Time from 1 May to 31 July each year, for vegetation protection and from 1 April to 30 September each year for forest protection).