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El Tololo
-O3-
| Observation |
| Category |
: |
Air sampling observation |
| Situation |
: |
ongoing |
| Time zone |
: |
Local time -4 |
| Sampling |
| Sampling height |
: |
2 |
| Description |
: |
continuous |
| Sampling and analysis frequency |
: |
data are recorded continuously (sampling rate every few seconds) and are stored as 15min averages |
| Sampling environment |
: |
El Tololo is a background station in a pristine arid environment. Local emissions are rare and vegetation is sparse. |
| Description for sampling analysis |
: |
tubing material: teflon 1/4" OD; 3m length; flow rate 1 l/min; no drying prior to analysis |
| Instrument and Analysis |
| Measurement method |
: |
Light absorption analysis (UV) |
| Current status and history of instrument |
: |
TECO 49–003, S/N #49978-285; all measurements of this time series (1995 - now) were made with the same analyzer. |
| Description of instrument |
: |
UV photometric ambient ozone analyzer with internal ozonator |
| Calibration |
| Current scale employed in the measurement |
: |
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| Measurement calibration |
: |
zero and (multi-point) span checks are performed twice weekly. |
| Scale and calibration(treasability) |
: |
instrument performance of the analyzer was assessed during the SMN/WMO/GAW - 4th Tropospheric Ozone Analyzer Intercomparion at the Servicio Meteorologico Nacional, Observatorio Central de Buenos Aires, Buenos Aires, Argentina in September, 2010. The instrument passed all checks and a comparison with an ozone traveling standard (TEI 49i-PS #0810-153) of the World Calibration Centre for Surface Ozone (WCC-Empa) confirmed that the calibration of the instrument was still valid. |
| Data Processing |
| Measurement unit |
: |
ppb |
| Data processing |
: |
data processing includes visual inspection of the time series and removal of span and zero checks. |
| Processing for averaging |
: |
Processing for Hourly Data:
ND denotes the number of available 15min averages per hour; 15-min averages are the highest time resolution operationally stored.
Processing for Daily Data:
ND denotes the number of available hourly averages per day.
Processing for Monthly Data:
ND denotes the number of available daily averages per month. |
| 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. |
| Other Information |
| Scientific aim |
: |
long-term investigation of O3 mole fractions in the unpolluted atmosphere in South America |
| Reference |
: |
L. Gallardo, J. Carrasco, G. Olivares, An analysis of ozone measurements at Cerro Tololo (30S, 70W, 2200 m.a.s.l.) in Chile, Tellus, 52B, 50-59 (2000).
R. Rondanelli, L. Gallardo, R.D. Garreaud, Rapid changes in ozone mixing ratios at Cerro Tololo (30deg10'S, 70deg48'W, 2200 m) in connection with cutoff lows and deep troughs, Journal of Geophysical Research, Vol. 107, No. D23, 4677, doi:10.1029/2001JD001334, 2002 |
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| submitted by Direccion Meteorologica de Chile |
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