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Zugspitze / Schneefernerhaus
-SO2-
| Observation |
| Category |
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Air sampling observation |
| Situation |
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ongoing |
| Time zone |
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Local time +1 |
| Sampling |
| Sampling height |
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30 |
| Description |
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continuous |
| Sampling and analysis frequency |
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Continuous, measuring interval is 10 seconds. The maximum time resolution provided by the data acquisition system is 1 minute. |
| Sampling environment |
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Zugspitze is the highest mountain of the German Alps (2964 m a.s.l.). It is located in southern Germany, about 90km southwest of Munich, at the Austrian border. Monitoring of air pollution up to 1999 was carried out from an aluminum sheltered cabin on the view point terrace (47°25'N, 10°59'E, 2962m a.s.l.). Trace gas measurements were re-located in 2000 to the new Environmental Research Station "Schneefernerhaus" at 2656m a.s.l. on the southern slope of Zugspitze.
Together with the Meteorological Observatory Hohenpeissenberg (40 km north), this platform establishes the Global Station Zugspitze/Hohenpeissenberg. The monitoring program is operated jointly by the Federal Environmental Agency (Umweltbundesamt, UBA) and the German Meteorological Service (Deutscher Wetterdienst, DWD).
SO2 is the most important source for sulfate aerosol and for that also important for cloud formation processes and climatic effects (e.g. anti-greenhouse effect). SO2/sulfuric acid affects the aerosol mass, aerosol chemistry, radiation effects of aerosol, formation of cloud condensation nuclei, is the most important trace gas for the particle new formation and is involved in acid rain formation. SO2 originates mainly from anthropogenen sources, i.e. from industrial combustion processes. In addition, it is emitted by volcanic eruptions. Major sinks are reaction by OH radicals and by wet deposition, i.e. by solution in cloud drops, in which it is converted to sulfurous acid and sulfuric acid. The mean life time in the atmosphere is around 3-4 days (life span against OH 5-20 days). SO2 can be used as tracer for European-wide air mass transport. |
| Description for sampling analysis |
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Stainless steel inlet line, 1 inch diameter, 5 m length, together with other trace gases. Residence time < 5 seconds by bypass pump. Inlet line is heated to avoid condensation.
Continuous SO2 UV pulsed fluorescence analyzer, model Thermo Instruments 43 BS, #43BS-51632-288.
The experimentally identified LDL with this set-up is about 50 pptv.
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| Instrument and Analysis |
| Measurement method |
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Fluorometry |
| Current status and history of instrument |
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Jan.2000 - Jan.2002 : Thermo Instruments 43 CTL, #43CTL-56118-306
Jan.2002 - Aug.2007 : Thermo Instruments 43 BS , #43BS-51632-288
Dec.2007 - ongoing : Thermo Instruments 43iTLE, |
| Description of instrument |
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Time resolution is one minute (limited by data acquisition system), LDL and resolution is about 50 ppt. The instrument is linear from LDL up to at least 50 ppb.
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| Calibration |
| Current scale employed in the measurement |
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Certified SO2 in N2 in cylinders and dynamic dilution with synthetic air is used for calibration.
From time to time inter-comparisons between Hohenpeissenberg and Schneefernerhaus site. |
| Measurement calibration |
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Certified SO2 in N2 in cylinders and dynamic dilution with synthetic air is used for calibration. For zero measurement ambient air after removal of SO2 by activated charcoal is used. Zero and span check every 49 hours, 5 point calibration twice per year.
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| Scale and calibration(treasability) |
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Calibration gases and analyzer are compared with the SO2 standard at Meteorological Observatory Hohenpeissenberg.
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| Data Processing |
| Measurement unit |
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ppb |
| Data processing |
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The data acquisition system provides one minute mean raw data. Zero/calibration factors and data protocols are used to convert raw data in calibrated data. Invalid data caused by local impact, malfunction or other effects were recognised by comparison/correlation with other trace substances and meteorological data or with information from the station logbook and were rejected. Data below LDL (50 ppt) were set to the 50% of LDL. Data below the negative LDL were rejected. 10 min mean values are generated by calculating the arithmetic mean of the remaining data with number of data more than 6. |
| Processing for averaging |
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Processing for Hourly Data:
Hourly data take the arithmetic mean of respective one minute mean validated data with the number of data more than 40.
Processing for Daily Data:
Daily data take the arithmetic mean of respective hourly data with the number of hourly data more than 16.
Processing for Monthly Data:
Monthly data take the arithmetic mean of respective hourly data with the number of daily data more than 20 (for February more than 19, respectively).
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| Data flag |
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Only validated data era sent to the WDCGG. |
| Data remarks |
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| Other Information |
| Scientific aim |
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Aerosol formation from gas phase, tracer for anthropogenic impact. |
| Reference |
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Stefan Gilge, Measurement of reactive Trace Gases at Hohenpeissenberg as Part of GAW, in „The German Contribution to the WMO/GAW Program: Upon the 225th anniversary of GAW Hohenpeissenberg Observatory, ed. W.Fricke, GAW Report 169, 2006
http://www.dwd.de/gaw
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| submitted by Meteorological Observatory Hohenpeissenberg, German Meteorological Service |
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