CO₂ _ PAL _ surface - insitu _ FMI _ data1

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Organization

NO	25
Acronym	FMI
Name	Finnish Meteorological Institute
Address 1
Address 2
Address 3	P.O. BOX 503 FI-00101 HELSINKI FINLAND
Country/Territory	Finland
Website	http://www.fmi.fi/en

Contact(s)

Last updated date	2024-11-11
Name	Juha Hatakka
Prefix
Email	juha.hatakka@fmi.fi
Organization No	25
Organization acronym	FMI
Organization name	Finnish Meteorological Institute
Organization country/territory	Finland
Address 1	Finnish Meteorological Institute
Address 2	Erik Palmenin aukio 1
Address 3	FI-00560 Helsinki, Finland
Country/territory	Finland
Tel	+358-29-539 5491
Fax	+358-29-539 3503

Collaborator(s)
Aim of Observation	Background observation
Data Time zone	UTC+02:00
Unit	ppm
Calibration Scale	9999-12-31 00:00:00 - 9999-12-31 23:59:59: WMO CO2 X2019
Instrument(s)	1998-07-01 00:00:00 - 2000-04-10 23:59:59: LI-6262 (Li-Cor Inc.)(NDIR) 2000-04-11 00:00:00 - 2005-08-18 23:59:59: LI-6252 (Li-Cor Inc.)(NDIR) 2005-08-19 00:00:00 - 2006-07-07 23:59:59: LI-6262 (Li-Cor Inc.)(NDIR) 2006-07-08 00:00:00 - 2009-01-26 23:59:59: LI-7000 (Li-Cor Inc.)(NDIR) 2009-01-27 00:00:00 - 2011-12-16 23:59:59: G1301 (Picarro)(CRDS) 2011-12-17 00:00:00 - 2012-06-10 23:59:59: G2401 (Picarro)(CRDS) 2012-06-11 00:00:00 - 2012-07-31 23:59:59: G1301 (Picarro)(CRDS) 2012-08-01 00:00:00 - 2012-10-17 23:59:59: LI-7000 (Li-Cor Inc.)(NDIR) 2012-10-18 00:00:00 - 9999-12-31 23:59:59: G2401 (Picarro)(CRDS)
Intake Height above ground level	9999-12-31 00:00:00 - 9999-12-31 23:59:59: 7 (m)
Sampling Frequency	1 minute
Measurement Calibration	Three working standards, a reference gas and a "target" gas cylinders are calibrated against a set of seven WMO/CCL station standards five to six times a year. This is made at the station with the system that is normally measuring ambient concentration. Analyser is calibrated against the working standards every 2.5 hours. Reference gas is measured every 7.5 hours together with a target cylinder. Each cylinder is measured for four minutes, and the last minute average is used in further calculations. Calibration of working standards (+reference and target) is made in pyramid fashion, with pyramid run through ca. 6-7 times (i.e. 12-14 measurements/cylinder). The CRDS system has one working standard (WS) cylinder, and one target (T) cylinder. WS cylinder is measured ca. 4 times a day, and T cylinder once a day. WS cylinder readings are used to compensate analyzer drift (response changes). Station standards (7 WMO/CCL cylinders) have been calibrated at the station several times against newer sets of WMO/CCL standards. Current scale is based on 2018 recalibrated set of 4 cylinders. The two systems gave very similar results, in 2010 the average difference between hourly mean values was 0.00 ppm with standard deviation of 0.09 ppm (Licor system was missing 2 months worth of data).
Data Processing	Data is collected from the NDIR analyser as one minute mean values with min,max,deviation (up to 2000-08-08 one minute mean every 5 minutes). These values are stored and used to calculate mixing ratios taking into consideration bracketing working standard measurements. For CRDS system the processing is similar. Data is flagged automatically for abnormal values (outliers), and this flagging is checked later on (when final results are calculated) manually.
Processing for averaging	[Hourly] Valid one minute mean values are averaged with standard deviations. [Daily] [Monthly]
Original Data Quality Flag	Hourly data before 2018 was flagged based on wind speed, hourly average standard deviations and 120 h back trajectories, which are calculated for every 3 hours. Since 2018 flagging is based only on wind speed and hourly standard deviation. Flags: M - missing value (or rejected due to system problems) Z - not classified: missing wind data (or trajectory data before 2018) X - not background air ("local"), value did not pass wind and/or standard deviation test 1 - marine background air (see below) 2 - continental background air (before 2010: trajectory >= 50% of the time over continent, 2010: trajectory < 20% of the time above sea) T - classification to marine or continental not possible Criteria for flag 'X': * wind speed <= 3.0 m/s during June-August, <= 4.0 m/s otherwise. * hourly stdev >= 0.5 ppm during July-August, >=0.3 otherwise Additional criteria for flag '1' (marine): * polynomial+harmonic fit were made for the whole data period (1999->) for data for which trajectory is >=70% of the time over sea. This was used to determine standard deviation (1.6 ppm) between the fit and measured results. Hourly averages that are farther away than 2stdev (3.2 ppm) are flagged with 'T'. Additional criteria for flag '2' (continental) since 2010 data: As above, except for trajectory is <20% of the time over sea. Standard deviation is 3.4 (2*stdev 6.8 ppm). Since 2010 data, source area (flags '1' and '2') analysis is based on dispersion model and footprints. Requirements for marine ('1'): less than 2% of the footprint is on continental areas, and in addition less than 20% on local area. For continental ('2') the requirement is less than 20% of the footprint is over marine areas. Since 2018 data trajectories have not been used in classification (no more '1' and '2' flags)
Data Quality Flag (Valid/Invalid)	Valid: X Valid (background): 1 Valid (background): 2 Valid (background): T Valid: Z Invalid: M
Observation Status	Operational/Reporting
Description	The sample is taken from a common sampling line (inlet at the height of 7 m above ground, line made of acid resistant stainless steel OD 60 mm, flow speeed ca. 20 m/s) at 3 litres/minute and dried cryostatically to dewpoint ca -25 C. The flow going to the NDIR analyser, 100 ml/min, is further dried with magnesiumperchlorate. The sample air of the CRDS (cavity ring-down spectroscopy) analyser is taken from the same common sampling line, and it is dried with a Nafion dryer since 2009-05-07 to dewpoint ca. -20 C. Since 2013-10-26 the CRDS system has been measuring sample air as it is (i.e. wet)
Meteorological Data Availability (1: Available)	Wind direction: 1 Wind speed: 1 Relative humidity: 1 Precipitation amount: 0 Air pressure: 1 Air temperature: 1 Dew point temperature: 1 Sea water temperature: 0 Sea surface water temperature: 0 Sea water salinity: 0 Sea surface water salinity: 0
Meteorological Data Description	Meteorological data may remain as first provided, even when greenhouse gas data are updated. Anemometer height is 9 m a.g.l. Wind speed and direction is calculated (as vectors) from 1-minute values for the whole hour.

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Related information

Format

Text (WDCGG Data Format Table, WDCGG Meteorological Data Format Table), NetCDF

Relation List (Is Part Of)

All CO₂ data contributed to WDCGG by GAW stations and mobiles by 2024-09-24
All CO₂ data contributed to WDCGG by GAW stations and mobiles by 2023-09-13
All CO₂ data contributed to WDCGG by GAW stations and mobiles by 2022-09-07
All CO₂ data contributed to WDCGG by GAW stations and mobiles by 2021-09-08
All CO₂ data contributed to WDCGG by GAW stations and mobiles by 2020-09-28
All CO₂ data contributed to WDCGG by GAW stations and mobiles by 2019-09-19
All CO₂ data contributed to WDCGG by GAW stations and mobiles by 2018-10-25

Geolocation Point

Latitude (north: +; south: -)	67.9736099243
Longitude (east: +; west: -)	24.1158332825

GAW Data Policy

"For Scientific purposes, access to these data is unlimited and provided without charge. By their use you accept that an offer of co-authorship will be made through personal contact with the data providers or owners whenever substantial use is made of their data. In all cases, an acknowledgement must be made to the data providers or owners and to the data centre when these data are used within a publication."

Citation format

This format is an example of the WDCGG standard citation.
Please follow the citation format which the data providers or owners indicate.

Juha Hatakka (FMI), Atmospheric CO₂ at Pallas by Finnish Meteorological Institute , dataset published as CO₂_PAL_ surface-insitu_FMI_data1 at WDCGG, ver. 2024-06-19-0538 (Reference date^*: YYYY/MM/DD)

* As the reference date, please indicate the date you downloaded the files.