====== TFMM trend methodology ====== This page allows for exchanging and share information on recommended methods for the TFMMM trend assessment in 2015. A summary of the recommendations from the workshop in Paris in November 2015 can be found in Laurence Rouil's [[http://www.nilu.no/projects/ccc/tfmm/paris_2014/presentations_18nov2014/trends_workplan.pptx|presentation]] ===== 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 [[emep:emep-experts:tfmmtrendstations|Selected stations]] **Discussion on trend methodology** [[http://www.msceast.org/trends/noteontrends.doc|A note on trend methodology by MSC-E]] [[https://wiki.met.no/_media/emep/emep-experts/mannkendall_note.pdf | A note on the use of Mann Kendall statistics by CCC ]] [[http://www.msceast.org/trends/methodology.doc|Description of MSCE trend methodology]] ===== Software tools ===== [[http://www.openair-project.org|Open Air R package]] [[http://en.ilmatieteenlaitos.fi/makesens|Makesens Excel tool for Trend analysis]] [[http://www.msceast.org/trends/program.zip|MSCE trend tool]] [[http://www.msceast.org/trends/Program_v1.zip|MSCE trend tool version 1]]