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TFMM trend methodology
At the TFMM web page you find presentations held at the TFMM workshop and relevant information of activities in the task force.
This wiki page aims to exchange and share information on recommended methods for the TFMMM trend assessment in 2015. Links to available and relevant papers and reports will be shared in addition to benchmark datasets, which could be used for calculation trends.
Which Reference Period?
All period: 1990-2012
Recent period: 2002-2012
| Comments: Is this ok? |
Wenche Aas: In the summary from the Paris workshop it was stated that the period should be from 1992-2012. But I think we have to start at 1990 since that is the reference year for the Gothenburg protocol. A question is whether the latter period 2002-2012 is 11 years (including 2002 and 2012), I assume so. If one wants to dived the two periods and look at the first period separately, that should then be 1990-2011 (12 years).
Which trends?
Species: PM10, PM25, O3, NO2, Deposition (S and N), heavy metals (Hg,Cd,Pb), POPs (BaP)
Filters: Transport Sectors, Day/Night…
| Comments: |
Wenche Aas: For studying trends in deposition it would be beneficial to actually rather look at concentrations in precipitation and air/aerosols, especially when looking at measured data since dry deposition is not measured. Precipitation amount can be look at separately or in addition to concentration in precipitation.
Statistical Methods
75% data coverage per year and 75% of period
References to statistical methods