1. Time Series and Trends at GAW Global Site Hohenpeissenberg
Christian Plass-Duelmer, Stefan Gilge, Harald Flentje, Anja Werner, Stéphane Sauvage
And the GAW Team at Hohenpeissenberg
TFMM Meeting, Krakow, May 2015

2. TFMM Meeting, Krakow, May 2015
Long-term observations at Hohenpeissenberg
TFMM Meeting, Krakow, May 2015

3. TFMM Meeting, Krakow, May 2015
Time series by monthly means (anthropog. VOC)
Fit of an exponential decay and sine-curve
Zeitreihen ausgewählter anthropogener Kohlenwasserstoffe
Yields:
exponential decay
seasonal amplitude
phase shift
Comparison of different time series
TFMM Meeting, Krakow, May 2015

4. TFMM Meeting, Krakow, May 2015
Exponential decay compared for different stations
Different Central European Stations
show similar trends -
gives confidence in observed trends
TFMM Meeting, Krakow, May 2015

5. TFMM Meeting, Krakow, May 2015
Hohenpeissenberg NOxy:
Monthly means, linear trends, 12 months running mean
12 months running means enable visualization of long-term changes
TFMM Meeting, Krakow, May 2015

6. TFMM Meeting, Krakow, May 2015
Linear trends of 12-months-running-means:
before and after 2000
trends need long-term observation
TFMM Meeting, Krakow, May 2015

7. TFMM Meeting, Krakow, May 2015
Non-organic trace gases
12-M-running-means, normalized to year 2000
Max.
Min.
TFMM Meeting, Krakow, May 2015

8. TFMM Meeting, Krakow, May 2015
Organic gases (alkanes)
Max.
Min.
Again, similar general max/min = „chemical weather“
Similar sources(fossil)/sinks(OH)/transport(meteo) fluctuations
Interesting tool for long-term trends: use of ratios
TFMM Meeting, Krakow, May 2015

9. Hohenpeissenberg aerosol time series Linear trends of monthly means
-37 ± 9 cm-3yr-1
Declining aerosol concentrations whereas increasing scattering ?
Neph data need to be checked w.r.t. humidity and sampling changes
TFMM Meeting, Krakow, May 2015

10. TFMM Meeting, Krakow, May 2015
PMF yields factors representing
different sources and different ageing
Factor contributions to total NMHC
Factor contributions to individual NMHC
NMHC annual/weekly patterns represent various source impacts –
powerful tool for model evaluation
Leuchner et al., 2015
TFMM Meeting, Krakow, May 2015

11. TFMM Meeting, Krakow, May 2015
Evaluation of CAMS Model
(Copernicus)
Expand NRT delivery from ACTRIS/GAW/ EMEP stations for CO, O3, NO, NO2, SO2
TFMM Meeting, Krakow, May 2015

12. ACTRIS
Aerosols, Clouds, and Trace gases Research Infrastructure Network
FP7-INFRASTRUCTURES
ACTRIS – 2
H2020-INFRAIA
“Integrating the key ground-based facilities for long-term observation of aerosols, cloud-aerosol interactions, and trace gases in Europe”
GAW+
EMEP-Aerosol
EMEP-VOC
EMEP-NOx
IGACO
GALION
Longitude [°]
Latitude [°]
Example: European VOC network
TFMM Meeting, Krakow, May 2015

13. Round Robin and Side-by-side intercomparison OVOC NOx in guest-lab
ACTRIS Quality Assessment
Round Robin and Side-by-side intercomparison
OVOC NOx
in guest-lab
Hohenpeissenberg
10x CLD LIF
CEAS
CAPS CRDS
5 on-line GC
1 off-line GC
DNPH/HPLC
3 PTR-MS
Good results can be achieved by suitable techniques, but challenging
Need for enhanced quality management – ACTRIS-2
TFMM Meeting, Krakow, May 2015

14. TFMM Meeting, Krakow, May 2015
Questions in trend assessment / verification of emissions
Which measurements do we need?
Those regulated (EC) and those relevant for atmospheric processes (GAW and EMEP) important: NO2 not by MO-converters, VOC not just NMHC but also OVOC/BVOC
What quality of measurements do we need?
Such that we can evaluate regulations and understand processes e.g. GAW/ACTRIS DQO‘s of 5-10%, standardized quality management (ACTRIS)
Which density of measurements do we need?
Model related question
How can we verify emissions?
Models, inverse modelling, source apportionment (e.g. PMF), trend analyses
How can we separate emission changes from transport/meteorology changes?
Models, variability in weekly and seasonal cycles,
Models and long-term observations must go hand in hand
TFMM Meeting, Krakow, May 2015

15. TFMM Meeting, Krakow, May 2015
Thanks!
We acknowledge the contribution by the ACTRIS Research Infrastructure Project supported by the European Union Seventh Framework Programme (FP7/ ) under grant agreement n
TFMM Meeting, Krakow, May 2015