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Hohenpeissenberg
-O3-
| 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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18 |
| Description |
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continuous |
| Sampling and analysis frequency |
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Continuous, measuring interval is 10 seconds (7 seconds flushing and 3 seconds integrating time). |
| Sampling environment |
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Hohenpeissenberg is an isolated mountain at 985 m a.s.l., 40 km north of Zugspitze (Alps) in a hilly area. The mountain rises 300m above the surrounding area, which is populated to an extent typical for central Europe and partly covered with meadows (~ 70%) and forests (~ 30%). The Meteorological Observatory situated on top of Hohenpeissenberg mountain has a long history of meteorological and climatological observations (since 1781) and is well-known for its long ozone record.
Ozone is a secondary pollutant, so it has no direct sources but it is produced from precursors like nitrogen oxides and VOC in presence of sunlight.
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| Description for sampling analysis |
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Continuous UV absorption, ethylene chemiluminescence and wet chemical potassium iodide analyzer.
Teflon PFA inlet line: about 18m above ground; 1/2 inch diameter, 4 m length, together with other trace gases; residence time < 2 seconds.
The Thermo Instruments TE 49 C -56028-306 is the master instrument. |
| Instrument and Analysis |
| Measurement method |
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Light absorption analysis (UV) |
| Current status and history of instrument |
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Jan.1971 - Dec.1986 : Potassium Iodide (self built)
Jan.1987 - Jun.1988 : Chemiluminescence (Monitor Labs)
Jun.1988 - Dec.1996 : UV abs. (Dasibi)
since Oct.1992 : Chemiluminescence, UPK (similar Bendix),
#UPK8002 920962
since Jan.1997 (add.): dual beam UV absorption, Thermo Instruments,
#TE49C - 56028-306
since Jan.1997 (add.): Potassium Iodid (self built, #56)
since Jan.2007 (add.): dual beam UV absorption, Thermo Instruments,
#TE49i - 0632519672 |
| Description of instrument |
: |
All analyzer working continuously. Time resolution is about 1 minute. They are linear for a brought range from 0 to at least 300 ppb. The LDL for the UV analyzers are about 0.5 ppb, for the other about 1 ppb.
The #TE49C - 56028-306 serves as "master instrument", the others as backup instruments |
| Calibration |
| Current scale employed in the measurement |
: |
TE 49i PS (primary standard) is used for calibration, traceable to GAW/CCL.
Audits by WCC in 1999, 2006 and 2011, all with excellent agreement.
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| Measurement calibration |
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A 5-point-calibration is carried out every second month with the following points: 0;100;50;150;30;70;0ppb. Our primary standard (TE 49 PS #49821-284) is compared to the WCC tansfer standard. The deviation
during the last field audit in June 2011 between the WCC standard and our calibration standard was smaller than 0.5%. Additionally the calibrations are checked by calculation according to Lamber-Beers-Law.
Several informal inter comparisons with other groups has been undertaken, with excellent agreement.
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| Scale and calibration(treasability) |
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The data refer to the WCC O3 standard. |
| Data Processing |
| Measurement unit |
: |
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 into calibrated data. Invalid data caused by local contamination, 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 detection limit (LDL; 1 ppb) are set to the half of detection limit. Data smaller than the neg. LDL ( < -1 ppb) are rejected.
Normally only data from the "master ozone analyzer" (TE 49C) are sent to the WDCGG. Gaps in data record, caused by calibration or malfunction of the TE49 #306, are filled up with data from the other instruments, if following precondition is fulfilled: The deviation between master instrument and respective instrument in the last six ten minutes mean values before and in the first six ten minutes mean values after the gap must be below 1% or 0.5 ppb (whichever is greater).
10 min mean values are generated by calculating the arithmetic mean of the remaining data with number of data being 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). |
| Data flag |
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only validated data are reported |
| Data remarks |
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| Other Information |
| Scientific aim |
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Key component for tropospheric chemistry, oxidation capacity of the atmosphere, interpretation with respect to ozone formation/ transport, climatic effects. |
| Reference |
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Gilge, S., C. Plass-Duelmer, W. Fricke, A. Kaiser, L. Ries, B. Buchmann, and M. Steinbacher, Ozone, carbon monoxide and nitrogen oxides time series at four alpine GAW mountain stations in central Europe, Atmos. Chem. Phys., 10, 12295–12316, 2010 (doi:10.5194/acp-10-12295-2010).
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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