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Zugspitze / Schneefernerhaus
-O3-
| Observation |
| Category |
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Air sampling observation |
| Situation |
: |
ongoing |
| Time zone |
: |
Local time +1 |
| Sampling |
| Sampling height |
: |
2670 |
| Description |
: |
continuous |
| Sampling and analysis frequency |
: |
Continuous sampling --- 500 ltr/minute with a borosilicate glass system, which is fortified by a stainless steel tube. Continous measurement. Every 10 seconds one value, which gives 1minute mean.
The minute data are visualized and flagged by the use of the meta information in the station logbook. Once a week a calibration with Span and Zero. and once a month a 5 point calibration. |
| Sampling environment |
: |
High mountain station. Effective short time sinks can happen because of the effect of NOx and NOy. Short time sources can happen because of stratospherical intrusions. Typically in winter the night time from 21:00h until 6:00h and in summer from 00:00h until 5:00 is especially close to the lower troposphere conditions. About this circumstances a masters work is in preparation. |
| Description for sampling analysis |
: |
Height of the line is 20 meters above the ground and 2.5m over the top of the measurement station. |
| Instrument and Analysis |
| Measurement method |
: |
Light absorption analysis (UV) |
| Current status and history of instrument |
: |
UV Absorption,
Thermo Science or thermo Fisher TS49i, starting in march 2008.
From 2001 until 2008 we used a TE49 on the same place. |
| Description of instrument |
: |
Thermo Environmental Instruments Inc.
# 49C 65220-347 |
| Calibration |
| Current scale employed in the measurement |
: |
WMO mole fraction scale |
| Measurement calibration |
: |
Calibration gas: gas calibrator, calibrated according to NIST standard. Calibrations are carried out every 25 hours with an additional monthly calibration. |
| Scale and calibration(treasability) |
: |
All data are based on WMO mole fraction scale. |
| Data Processing |
| Measurement unit |
: |
ppb |
| Data processing |
: |
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 impact, malfunction or other effects are detected by comparison/ correlation with other trace substances and meteorological data and with information from the station logbook and then are rejected. 30 min mean values are generated by calculating the arithmetic mean of the remaining data with number of data more than 15. For reporting to GAW hourly mean values are calculated from these half hourly data. |
| Processing for averaging |
: |
Processing for Hourly Data:
The validated and flagged data are aggregated to hourly and daily data with a self written software tool, called dafit.
This is available for whole GAW for free.
The tool facilitates automation and standardization of data quality assurance, validation, flagging, aggregation and export to WDCGG.
More info and a detailed description on the website www.gawstat.de
The documentation about the automated export to WDCGG will be finished in November 2015.
Processing for Daily Data:
Daily: Take the arithmetic mean of selected half hourly data with the number of data more than 67%
Processing for Monthly Data:
Monthly: Take the arithmetic mean of selected half hourly data with the number of data more than 76% of underlying 1 minute data in case not noted, that other criterions had been applied. |
| Data flag |
: |
Three digit code, according to NOAA scheme Scheme for hourly data
… Usable, representative data, background conditions – valid Data
C.. Calibration – invalid Data, not representative—data value -999
I.. Instrument malfunction, invalid data or artefact, here the
data value will be -999
O.. Outlier or Spike, not usable, typically for short time
means,like 1minute – invalid data- not representative- data
value -999
A.. Audit or Intercomparison measurement, valid data, not
representative, data value -999
N.. No measurement, instrument off, e.g. under repair -- here the
data value will be -999.
4.. Standard deviation over 4 sigma, output -999
.B. Background polluted air mass– valid data, not representative
.L. Locally polluted air – valid data, not representative
.U. non representative air mass, such as daily convective upwind
during summer – valid data, not representative
.S. Stratospheric intrusion – valid data, not representative
.R. Correct measured but not representative and possibly
correctable e.g. such as negative Values or below detection
limit
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| Data remarks |
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| Other Information |
| Scientific aim |
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To provide data for research to reveal long term trends of air pollution, long distance transport and climate change in Central Europe. |
| Reference |
: |
"Qualitatssicherungs-Handbuch des UBA-Messnetzes", UBA Texte 28/04, (Handbook for quality assurance for the measurement network for the Federal Environmental Agency, Germany), Dr.Klaus Nienerowski, Umweltbundesamt, Berlin, Juni 2004
http://www.umweltbundesamt.de/luft/luftmessnetze/ubamessnetz.htm |
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| submitted by Federal Environmental Agency Germany |
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