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 Organization

NO 27
Acronym HKO
Name Hong Kong Observatory
Address 1
Address 2 Hong Kong Observatory
Address 3 134A Nathan Road, Kowloon, Hong Kong.
Country/Territory Hong Kong, China
Website http://www.hko.gov.hk

 Contact(s)

Name David H.Y. Lam
Prefix Dr.
Email dlam@hko.gov.hk
Organization No 27
Organization acronym HKO
Organization name Hong Kong Observatory
Organization country/territory Hong Kong, China
Address 1
Address 2
Address 3
Country/territory Hong Kong, China
Tel +852 2926 8024
Fax +852 2375 2645
Last updated date 2019-10-15


Name Olivia S.M. Lee
Prefix Ms.
Email olee@hko.gov.hk
Organization No 27
Organization acronym HKO
Organization name Hong Kong Observatory
Organization country/territory Hong Kong, China
Address 1
Address 2
Address 3
Country/territory Hong Kong, China
Tel +852 2926 8421
Fax +852 2375 2645
Last updated date 2019-10-15


 Background observation
 UTC+08:00
 ppm
 9999-12-31 00:00:00 - 9999-12-31 23:59:59: WMO CO2 X2007
 9999-12-31 00:00:00 - 9999-12-31 23:59:59: LI-820 from LI-COR Biosciences Ltd.(NDIR)
 9999-12-31 00:00:00 - 9999-12-31 23:59:59: 4 (m)
 1 second
 The LI820 CO2 analyzer is calibrated once every two weeks (based on past experience of the stability of the analyzer; the zero drift as well as the overall system drift is less than 2 ppm in two weeks' time). During the calibration, secondary standard gases of concentration 404 ppm and 603 ppm are used for performance check and span calibration of the LI820 respectively. Before the calibration of LI820, the secondary gases are checked for any drift using a LI7000 CO2 analyzer which is calibrated using the NOAA standard gases.

Before the calibration, the LI820 is checked for its performance using the 404 ppm secondary standard gas and a zero gas.
1. The 404 ppm standard gas is applied to check for any instrument drift;
2. The zero gas is applied to check for any zero drift;
3. The measured data from steps (1) and (2) are kept for future ref.;
4. Due to the limitation of LI820, only the zero and span calibration are carried out;
5. The LI820 is set zero using the zero gas and then the span point is set using the 603 ppm secondary standard gas;
6. Finally, the performance of LICOR at around 400 ppm is checked using the 404 ppm secondary standard gas and the data is kept for future reference.
 1. 1-minute average CO2 concentration is calculated from 60 1-second data once every minute;
2. The time series of the raw 1-minute average CO2 concentration is first examined manually to identify any suspicious/erroneous data. Erroneous data are not used for compilation of the hourly and daily mean.
3. Hourly mean CO2 concentration is derived from the 1-minute average;
4. Daily mean CO2 concentration is derived from the hourly mean.
 [Hourly] Please refer to the "data processing" section
 [Daily] Please refer to the "data processing" section
 [Monthly] Monthly mean are derived from the daily mean
 At present, only daily mean CO2 concentration data are submitted and data quality assurance have been carried out at HKO. Hence all data QC flags are 1, meaning data checked OK.
 Valid: 1
 Valid: 2
 Invalid: 3
 Operational/Reporting
 
No data available