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 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

Selected stations

Discussion on trend methodology

A note on trend methodology by MSC-E

A note on the use of Mann Kendall statistics by CCC

Description of MSCE trend methodology

Software tools

Open Air R package

Makesens Excel tool for Trend analysis

MSCE trend tool