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Jungfraujoch
-O3-
| Observation |
| Category |
: |
Air sampling observation |
| Situation |
: |
ongoing |
| Time zone |
: |
Local time +1 |
| Sampling |
| Sampling height |
: |
|
| Description |
: |
continuous |
| Sampling and analysis frequency |
: |
Continuous |
| Sampling environment |
: |
measurements in pristine air, usually negligible local sources |
| Description for sampling analysis |
: |
UV Absorption |
| Instrument and Analysis |
| Measurement method |
: |
Light absorption analysis (UV) |
| Current status and history of instrument |
: |
UV Photometer |
| Description of instrument |
: |
until 26 June 2012: TEI49C (Thermo Environmental Instruments Inc.)
since 26 June 2012: Thermo 49i (Thermo Scientific) |
| Calibration |
| Current scale employed in the measurement |
: |
NIST SRP #15 |
| Measurement calibration |
: |
Every 25 hours an automatic zero-check and an automatic span-check is performed. Manual check is performed every two weeks and manual calibration is performed every 3 months. O3-Concentrations are referred to the NIST SRP#15.
A second O3 instrument is running on-site in parallel for quality control purposes since March 1992.
All instruments undergo comprehensive instrument tests and quality check after first receipt and before being installed at the measurement sites. In operation, instruments are replaced in regular intervals (roughly 2 years) and are sent to manufacturer representatives in Switzerland for service such as cleaning and replacement of wear parts. This is again followed by standard quality checks / instrument tests at Empa. Standard operating procedures exist for the instrument tests, the regular on-site maintenance and daily and monthly data processing procedures.
|
| Scale and calibration(treasability) |
: |
NIST SRP #15 |
| Data Processing |
| Measurement unit |
: |
ppb |
| Data processing |
: |
Data availability required for calculation of hourly averages: >= 75% of 10-minute values."
|
| Processing for averaging |
: |
Processing for Hourly Data:
Estimated standard uncertainty for hourly averages:
until 31 December 2007: 1.2 ppbv for values below 60 ppbv; 2 % for values greater than 60 ppbv.
[2008-01-01 thru 2009-01-01] uncertainty = [(0.6028 ppb)^2 + (0.0088 *c)^2]^0.5;
[2009-01-01 thru 2010-01-01] uncertainty = [(0.8190 ppb)^2 + (0.0085 *c)^2]^0.5;
[2010-01-01 thru 2015-01-01] uncertainty = [(0.8351 ppb)^2 + (0.0086 *c)^2]^0.5
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| Data flag |
: |
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| Data remarks |
: |
Data are given as mole fractions with respect to moist air, i.e. no sample drying was applied prior to analysis. Please refer to the standard literature and make use of the available meteorological data to convert the data from moist to dry air mole fractions.
SD: If the SD is listed: Instead of the SD (standard deviation), the standard uncertainty is given.
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| Other Information |
| Scientific aim |
: |
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| Reference |
: |
Logan, J.A., J. Staehelin, I.A. Megretskaia, J.-P. Cammas, V. Thouret, H. Claude, H. de Backer, M. Steinbacher, H.E. Scheel, R. Stübi, M. Fröhlich, R. Derwent, 2012. Changes in ozone over Europe: analysis of ozone measurements from sondes, regular aircraft (MOZAIC) and alpine surface sites. Journal of Geophysical Research, 117, D09301, doi: 10.1029/2011JD016952.
Parrish D. D., K. S. Law, J. Staehelin, R. Derwent, O. R. Cooper, H. Tanimoto, A. Volz-Thomas, S. Gilge, H. E. Scheel, M. Steinbacher, E. Chan, 2012. Long-term changes in lower tropospheric baseline ozone concentrations at northern mid-latitudes. Atmospheric Chemistry and Physics, 12, 11485-11504. |
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| submitted by Swiss Federal Laboratories for Materials Testing and Research |
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