Abstract:
Version 2.0
This data set contains mesospheric carbon monoxide (CO) data acquired by the ground-based microwave radiometer of the British Antarctic Survey (BAS radiometer) stationed at Troll station in Antarctica (72 deg S, 2.5 deg E, 1270 amsl). The BAS radiometer has been designed in order to study the effects of energetic particle precipitation on the middle and upper atmosphere, using nitric oxide and ozone measurements. This data set contains the CO measurements carried out in order to study the dynamical context.
The data set covers the period from February 2008 to January 2010, however, due to very low CO concentrations below approximately 80 km altitude in summer, profiles can only be retrieved during Antarctic winter. CO is measured for approximately 2 hours each day (80 percent of the profiles are within +-2 hours around local noon) and profiles are retrieved approximately every half hour. The retrieved profiles, cover two independent layers in the pressure range from 1 to 0.01 hPa (approximately 48 to 80 km, altitude resolution of approximately 16 km).
In this version of the data; an additional column of "apriori vmr" has been included in the data files.
Keywords:
Espy, P., Straub, C., & Newnham, D. (2012). Middle atmospheric carbon monoxide above Troll station, Antarctica from February 2008 - January 2010: V2.0 (Version "2.0") [Data set]. Polar Data Centre; British Antarctic Survey, Natural Environment Research Council; Cambridge, CB3 0ET, UK.. https://doi.org/10.5285/25d329ad-69de-4bd3-846d-427863b27781
| Creation Date: | 2013-04-23 |
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| Dataset Progress: | Complete |
| Dataset Language: | English |
| ISO Topic Categories: |
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| Parameters: |
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| Personnel: | |
| Name | Dr Patrick Espy |
| Role(s) | Investigator |
| Organisation | Norwegian University of Science and Technology |
| Name | Dr David Newnham |
| Role(s) | Investigator |
| Organisation | British Antarctic Survey |
| Name | Dr Corinne Straub |
| Role(s) | Investigator |
| Organisation | Norwegian University of Science and Technology |
| Name | Mr Peter J Kirsch |
| Role(s) | Metadata Author |
| Organisation | British Antarctic Survey |
| Parent Dataset: | N/A |
| Lineage: | The ground-based microwave radiometer of the British Antarctic Survey (BAS) measures spectra in the region of the rotational transitions centered at 250.796 GHz (nitric oxide, NO), 249.79 GHz and 249.96 GHz (ozone, O3) and 230.538 GHz (carbon monoxide, CO). A three-way mechanical chopper system selects the microwave signal either from the main reflector pointing to the sky at 30 deg elevation angle, a 60 K cold load or an ambient-temperature calibration load mounted on the chopper wheel, and directs it into the main receiver. The sky signal is then calibrated using the Dicke switching technique. One calibration cycle takes 26 s with 8 s integration time on each target. However, in order to achieve a high enough signal to noise ratio for the profile retrieval, several measured spectra are integrated. To produce this data set 80 spectra from consecutive calibration cycles were averaged, which under good observing conditions results in a measurement noise of less than 0.15 K and an integration time of less than 30 minutes. Spectra with measurement noise higher than 0.25 K, due to e.g. high tropospheric opacity, were not considered for profile retrieval. During the winters 2008 and 2009 (492 measurement days) the radiometer acquired a total of 1974 integrated spectra over 394 days that are suited for profile retrieval. The inversions of the CO spectra were performed using the optimal estimation method implemented in the Qpack software package (v2.0.0). The forward model is provided by the Atmospheric Raditative Transfer Simulator (ARTS), a modular program simulating atmospheric radiative transfer. |
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| Temporal Coverage: | |
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| Start Date | 2008-02-29 |
| End Date | 2009-10-31 |
| Spatial Coverage: | |
| Latitude | |
| Southernmost | -72.01667 |
| Northernmost | -72.01667 |
| Longitude | |
| Westernmost | 2.53333 |
| Easternmost | 2.53333 |
| Altitude | |
| Min Altitude | 1270 metres |
| Max Altitude | 1270 metre |
| Depth | |
| Min Depth | N/A |
| Max Depth | N/A |
| Location: | |
| Location | Antarctica |
| Detailed Location | Troll |
| Sensor(s): |
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| Distribution: | |
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| Distribution Media | Online Internet (HTTP) |
| Distribution Size | N/A |
| Distribution Format | ASCII |
| Fees | N/A |