In line with the GAW Data Policy, users should contact the contributors of all data of interest and propose co-authorship or acknowledgement.
Organization
| NO | 7 |
|---|---|
| Acronym | ANSTO |
| Name | Australian Nuclear Science and Technology Organisation |
| Address 1 | Locked Bag 2001 |
| Address 2 | Kirrawee DC, NSW 2232 |
| Address 3 | Australia |
| Country/Territory | Australia |
| Website | http://www.ansto.gov.au/ |
Contact(s)
| Name | Alastair Williams |
|---|---|
| Prefix | Dr. |
| agw@ansto.gov.au | |
| Organization No | 7 |
| Organization acronym | ANSTO |
| Organization name | Australian Nuclear Science and Technology Organisation |
| Organization country/territory | Australia |
| Address 1 | ANSTO, Locked Bag 2001 |
| Address 2 | Kirrawee DC, NSW 2232 |
| Address 3 | Australia |
| Country/territory | Australia |
| Tel | +61 2 9717 3694 |
| Fax | |
| Last updated date | 2020-06-10 |
| Name | Scott Chambers |
|---|---|
| Prefix | Dr. |
| szc@ansto.gov.au | |
| Organization No | 7 |
| Organization acronym | ANSTO |
| Organization name | Australian Nuclear Science and Technology Organisation |
| Organization country/territory | Australia |
| Address 1 | ANSTO, Locked Bag 2001 |
| Address 2 | Kirrawee DC, NSW 2232 |
| Address 3 | Australia |
| Country/territory | Australia |
| Tel | +61 2 9717 3058 |
| Fax | |
| Last updated date | 2020-06-10 |
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| Atmospheric tracer | |||||||
| UTC+02:00 | |||||||
| mBq/m3 | |||||||
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9999-12-31 00:00:00 - 9999-12-31 23:59:59: Unknown |
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9999-12-31 00:00:00 - 9999-12-31 23:59:59: 1500 L(Unknown) |
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9999-12-31 00:00:00 - 9999-12-31 23:59:59: 30 (m) |
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| hourly | |||||||
| Ambient radon counts at the time of the calibration peak are estimated by linearly interpolating the ambient values between the start and end points of the calibration injection (a period of 8 - 10 hours). This procedure is most reliable when air mass fetch over the calibration period is oceanic. The net peak count is then determined by removing the ambient count rate from the peak calibration count rate. The net peak count is then converted to a value in counts per second. The radon concentration in the tank at the time of peak counts is then estimated as a ratio of the source radon delivery rate (2.501 Bq/min 222Rn) and the sample flow rate (90 L/min). A calibration factor (counts per second, per Bq/m3) is then determined as the ratio of the net peak counts per second and the radon concentration in the detector. This calibration factor is scaled up by 7% to account for the fact that the radon concentration in the detector would not have fully come to equilibrium within the 4-6 hour injection period. The raw 30 minute detector counts are aggregated to hourly values, the instrumental background is removed, and then the calibration factor is applied to derive hourly radon concentrations in Bq/m3. | |||||||
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All reported hourly 222Rn concentrations are in mBq/m3. Prior to removing instrumental background counts and calibrating to concentrations, the monthly raw data are checked for spiking (usually electrical noise) or periods of instrument malfunction. These periods, as well as calibration and instrumental background check periods are set to a value of -999.999 in the data stream. The following information is to be used as a GUIDE ONLY to processing and should be verified using back-trajectory analysis: - Air with radon concentrations >0.2 Bq/m3 has likely experienced recent (South African) land contact. - Air with radon concentrations between 0.04 - 0.2 Bq/m3 may have experienced distant (South American) terrestrial influence. - Air masses in equilibrium with the oceanic radon source (ie that have spent a long time within the marine boundary layer, away from land) are likely to have radon concentrations between 0.02-0.04 Bq/m3. - Air masses with radon concentrations between 0.0 - 0.2 Bq/m3 likely represent mixing of aged baseline tropospheric air with marine boundary layer air. - Depending on the species of interest (and the distribution of sources/sinks in the MBL/troposphere), any air masses with radon concentrations between 0.0 - 0.04 Bq/m3 may be considered "baseline". |
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[Hourly] Hourly data are aggregates of 30-minute counts and calibrated as described above. All periods of invalid data are shown as -999.999. If one 30-minute sample of the hour is bad/missing, the whole hour is flagged as "-999.999". No other averaging is performed. [Daily] [Monthly] |
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| There is no data quality flag. Bad/missing data points are indicated by -999.999 in the data stream. | |||||||
| Temporarily suspended | |||||||
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- Continuous hourly atmospheric 222Rn concentrations are measured directly (not via filtered ambient progeny) at Cape Point using a 1500L dual flow loop, two filter detector. - Time series have not been shifted to account for sensor response and delay times (total shift recommended: 60min). - No STP corrections have been applied. The principal of operation for ANSTO-built dual flow loop two filter detectors is described in Whittlestone and Zahorowski (1998) and Chambers et al. (2011). The instrument response time (time to reach half-peak magnitude) is 45 minutes. To account for the response time, and the sample delay, a lag of 1 hour is recommended compared to simultaneously observed parameters. The instruments 'lower limit of detection' (defined here to be the radon concentration at which the counting error first exceeds 30%) is approximately 0.03 Bq/m3. The detectors observation range spans 5 orders of magnitude. Assuming a Poisson process for 222Rn activity, the median standard deviation of ambient hourly counts is 6% the reported concentration (influenced by the fact that ambient concentrations are not necessarily constant over the hour). Instrumental background counts (primarily due to the accumulation of long-lived 210Pb on the detectors second filter) are characterised every 3 months. The background (modelled linearly with time) is removed from the raw counts prior to calibration. Typically, the standard deviation of a background measurement is equivalent to about 0.005 Bq/m3. Consequently, when ambient radon concentrations fall well below the detection limit, very small negative concentrations can sometimes be reported. The 1500L radon detector, designed and built by the Australian Nuclear Science and Technology Organisation (ANSTO), is situated inside a building of the Cape Point station to avoid being subjected to large diurnal temperature fluctuations and buffeting winds. Sample air is drawn from 30m agl on the sampling tower to the base of the tower through 40mm HDPE pipe using a stack blower (Becker, SV 8.130/1-01). A 'goose-neck' inlet has been fitted to the end of the inlet line to minimise the ingestion of precipitation. Between the stack blower and detector the sample air is ducted through 19mm reinforced plastic hose. Prior to entering the detector an additional 500L delay volume has been added to the sampling line. At the sampling flow rate of 90 L/min the total volume of the intake line results in a delay of approximately 6 minutes. This is sufficient time to reduce the ambient 220Rn (thoron) concentration to negligible levels. The sample exhaust valve of the detector is left slightly constricted such that, with the stack blower upstream of the detector, the portion of the inlet pipe close to the surface, as well as the detector itself, are always maintained at a slight positive pressure compared to ambient (+100 Pa). This minimises the likelihood of near-surface air (high in 222Rn and 220Rn) entering the sampling stream should any small leaks develop over time. |
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Wind direction: Wind speed: Relative humidity: Precipitation amount: Air pressure: Air temperature: Dew point temperature: Sea water temperature: Sea surface water temperature: Sea water salinity: Sea surface water salinity: |
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Meteorological data may remain as first provided, even when greenhouse gas data are updated. |
No DOI available
Related information
| Format | Text (WDCGG Data Format Table, WDCGG Meteorological Data Format Table), NetCDF | ||||
|---|---|---|---|---|---|
| Relation List (Is Part Of) |
All 222Rn data contributed to WDCGG by GAW stations and mobiles by 2023-08-16 All 222Rn data contributed to WDCGG by GAW stations and mobiles by 2022-07-11 All 222Rn data contributed to WDCGG by GAW stations and mobiles by 2021-02-22 All 222Rn data contributed to WDCGG by GAW stations and mobiles by 2020-06-19 All 222Rn data contributed to WDCGG by GAW stations and mobiles by 2019-03-07 All 222Rn data contributed to WDCGG by GAW stations and mobiles by 2018-06-08 |
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| Geolocation Point |
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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.
Please follow the citation format which the data providers or owners indicate.
Alastair Williams (ANSTO),
Scott Chambers (ANSTO),
Atmospheric 222Rn
at Cape Point by Australian Nuclear Science and Technology Organisation
,
dataset published as 222Rn_CPT_
surface-insitu_ANSTO_data1 at WDCGG,
ver. 2023-11-30-0852 (Reference date*: YYYY/MM/DD)
* As the reference date, please indicate the date you downloaded the files.
* As the reference date, please indicate the date you downloaded the files.
Reference(s)
| 1 | Whittlestone S. and Zahorowski W (1998) Baseline radon detectors for shipboard use: development and deployment in the first Aerosol Characterization Experiment (ACE 1). J. Geophys. Res. 103, 16743-16751 |
|---|---|
| 2 | Zahorowski W., Griffiths AD, et al (2013) Constraining annual and seasonal radon-222 flux density from the Southern Ocean using radon-222 concentrations in the boundary layer at Cape Grim, Tellus B, 65, 19622, http://dx.doi.org/10.3402/tellusb.v65i0.19622 |
| 3 | Botha R, Labuschagne C, Williams AG, Bosman G, Brunke EG, Rossouw A and Lindsay R, 2018: ‘Characterising fifteen years of continuous atmospheric radon activity observations at Cape Point (South Africa)’. Atmospheric Environment 176, 30-39. https://doi.org/10.1016/j.atmosenv.2017.12.010 |
| 4 | Chambers S, Williams AG, Zahorowski W, Griffiths A, Crawford J (2011) Separating remote fetch and local mixing influences on vertical radon measurements in the lower atmosphere. Tellus 63B:843-859 |
