| ![](../../../figure/gaw_stations.gif)
Pic du Midi
-O3-
Observation |
Category |
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Air sampling observation |
Situation |
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ongoing |
Time zone |
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UTC |
Sampling |
Sampling height |
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4 |
Description |
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continuous |
Sampling and analysis frequency |
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O3 is sampled every 10 seconds. Data are averaged every five minutes, and stored in database. |
Sampling environment |
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Situated in free troposphere, this station receive synoptic scale environnemental influences.
On the one hand, industrial pollution from plain activities , on the other hand, the downwards movement of stratospheric ozone
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Description for sampling analysis |
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Instrument and Analysis |
Measurement method |
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Light absorption analysis (UV) |
Current status and history of instrument |
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Thermo Environmental Instruments 49C |
Description of instrument |
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Ranges: 0-0.005 to 200ppm
0-0.1 to 400 mg/m3
Zero noise: 0.5 ppb RMS
Zero drift: <1ppb/24 hour
<2ppb/7 day
Span drift: <1% per month
Precision: 1 ppb |
Calibration |
Current scale employed in the measurement |
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Traceable to national standard scale ( EMD : Ecole des Mines de Douai - France ) |
Measurement calibration |
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Scale and calibration(treasability) |
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Data Processing |
Measurement unit |
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ppb |
Data processing |
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The raw data from the instrument is collected by the data acquisition system and sended to database computer in five minutes average raw data |
Processing for averaging |
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Processing for Hourly Data: Hourly data are generated by arithmetic means of the previous hour data
Invalid data are not included. An hour interval with less than 75% avalabl values is forced with a "-999" mean Processing for Daily Data: Daily data are generated by arithmetic means of the previous day data
Invalid data are not included. An daily interval with less than 75% avalable values is forced with a "-999" mean Processing for Monthly Data: Monthly data are generated by arithmetic means of the previous month data
Invalid data are not included. An monthly interval with less than 75% avalable values is forced with a "-999" mean |
Data flag |
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Data remarks |
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Other Information |
Scientific aim |
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Reference |
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submitted by Laboratoire d'Aérologie |
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