H. Fagerli, TFMM Bordeux, 24-26 april 2008 Using the EMEP Intensive campaign data for evaluating the EMEP model – first results for N H. Fagerli, TFMM Bordeux, 24-26 april 2008

Background Essential for the deposition/transport how much is in gas phase and how much is particles Little data (and with artefacts) from the EMEP network ’Only’ daily data – difficult to study processes that differ in day/night

Questions Do we distribute gas-particle correctly ? Coarse versus fine nitrate Do the model have the correct diurnal variations? (results with the updated model version) 1.) Some material from before

Available data (total=13 sites) HNO3 NH3 PM1 PM25 PMco PM10 aerosol GB33 06,30mn GB36 06 GB48 06,07 CH02 06,07, 07, DE44 07 IT04 NL11 06(no3),07 IE31 AT02 ES17 FI17 IT01 NO01 Blue: hourly data Red: daily data Lots of problems in measurement data!

June, 2006 Daily Hourly Fine nitrate tends to be underestimated in june 06 No systematic relation between over-/underestimated HNO3 and part. NO3

June, 2006 (Fine and) Coarse nitrate slightly underestimated

EMEP network – june 2005 HNO3: mixed Nitrate: underestimated =same conclusions as from Intensive campaign

January, 2007 Nitric acid underestimated in winter Nitrate ok except IT04

January, 2007 Fine nitrate slightly underestimated, coarse nitrate mixed, PM10 low

EMEP network – jan 2005 HNO3: mixed (IT01 overestimated) Nitrate: mixed (in general not as good comparison as the campaign)

Summary, HNO3-NO-3 partitioning Both coarse and fine nitrate underestimated in summer, HNO3 mixed. Agrees with comparison to EMEP network In january EMEP Intensive campaign, the modelled nitrate is in agreement or slightly lower than measurement for nitrate (fine and coarse). HNO3 is underestimated. Comparison with EMEP network show mixed results for both. Do different methods explain this or the selection of sites?

June, 2006 No systematic behaviour for NH3/NH4+

EMEP network – june 2005 NH3, NH4+ and sum mixed, but somewhat Low (too little formation of NH4NO3?)

January 2007 No systematic behaviour for NH3/NH4+ fine

EMEP network, jan 2005 NH3 and NH4+ ; no systematic behaviour

Conclusion NH3-NH4+ partitioning Mixed NH3 in june, somewhat low NH4+ -campaign: agree with EMEP network comparison Intensive campaign and network show no systematic behaviour in january

Diurnal variation, Cabauw No systematic Behaviour in summer Typically low in winter Model capture peak around noon (except GB48 do not have this- very little and strange data) and the lack of daily variation in winter

Ammonia, daily variation, june 06 Model and observations show opposite variation (except for NL11). Most extreme example:

Ammonia, daily variation, january 07

If NH3 is too low during the day – could this be the reason for underestimating NH4NO3 in june (only 3 sites to look at)? NH3 HNO3 Site: HARWELL (GB36) NO3- (PM25)

Diurnal variation of NH3 emissions changed HNO3 Site:HARWELL (GB36) NO3- (PM25)

Conclusions The new data allows for a more comprehensive evaluation of the nitrogen chemistry in the model – we have just begun… In general better comparison with Intensive campaign data Using campaign data or data from the ’standard’ EMEP network give same conclusions (except for HNO3 winter): No systematic behavior for reduced nitrogen. Low nitrate in summer, low HNO3 in winter. Low coarse nitrate. Consequences for the EMEP model: Revise NH3 emissions diurnal variation? Look at temperature effect in the equilibrium module Formation of coarse nitrate

Different methods, IT01, 2006 Filterpack+ denuder PM10 PM25

Different methods, IT01, 2007 Filterpack + denuder PM25

GB48

Cabauw, june 2006 Why so much PMco?

Cabauw, january 2007

Cabauw (NL11) JUNE 06 JAN 07 High HNO3/low NO3(coarse) Substantial coarse no3 Low nh3 All comp underestimated Low/no coarse NH4

Diurnal variation of NH3 emissions changed HNO3 Site: Auchencort (GB48) NO3- (PM25)

Diurnal variation of NH3 emissions changed HNO3 Site: Cabauw (NL11) NO3- (PM25)