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| Titel |
Propagation of radiosonde pressure sensor errors to ozonesonde measurements |
| VerfasserIn |
R. M. Stauffer, G. A. Morris, A. M. Thompson, E. Joseph, G. J. R. Coetzee, N. R. Nalli |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1867-1381
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 7, no. 1 ; Nr. 7, no. 1 (2014-01-10), S.65-79 |
| Datensatznummer |
250115557
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| Publikation (Nr.) |
 copernicus.org/amt-7-65-2014.pdf |
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| Zusammenfassung |
| Several previous studies highlight pressure (or equivalently, pressure
altitude) discrepancies between the radiosonde pressure sensor and that
derived from a GPS flown with the radiosonde. The offsets vary during the
ascent both in absolute and percent pressure differences. To investigate
this problem further, a total of 731 radiosonde/ozonesonde launches from the
Southern Hemisphere subtropics to northern mid-latitudes are considered,
with launches between 2005 and 2013 from both longer term and campaign-based
intensive stations. Five series of radiosondes from two manufacturers
(International Met Systems: iMet, iMet-P, iMet-S, and Vaisala: RS80-15N and
RS92-SGP) are analyzed to determine the magnitude of the pressure offset.
Additionally, electrochemical concentration cell (ECC) ozonesondes from
three manufacturers (Science Pump Corporation; SPC and ENSCI/Droplet
Measurement Technologies; DMT) are analyzed to quantify the effects these
offsets have on the calculation of ECC ozone (O3) mixing ratio profiles
(O3MR) from the ozonesonde-measured partial pressure. Approximately
half of all offsets are > ±0.6 hPa in the free
troposphere, with nearly a third > ±1.0 hPa at 26 km,
where the 1.0 hPa error represents ~ 5% of the total
atmospheric pressure. Pressure offsets have negligible effects on O3MR
below 20 km (96% of launches lie within ±5% O3MR error
at 20 km). Ozone mixing ratio errors above 10 hPa (~ 30 km),
can approach greater than ±10% (> 25% of launches
that reach 30 km exceed this threshold). These errors cause disagreement
between the integrated ozonesonde-only column O3 from the GPS and
radiosonde pressure profile by an average of +6.5 DU. Comparisons of total
column O3 between the GPS and radiosonde pressure profiles yield
average differences of +1.1 DU when the O3 is integrated to burst
with addition of the McPeters and Labow (2012) above-burst O3 column
climatology. Total column differences are reduced to an average of −0.5 DU
when the O3 profile is integrated to 10 hPa with subsequent addition of
the O3 climatology above 10 hPa. The RS92 radiosondes are superior in
performance compared to other radiosondes, with average 26 km errors of
−0.12 hPa or +0.61% O3MR error. iMet-P radiosondes had average
26 km errors of −1.95 hPa or +8.75 % O3MR error. Based on
our analysis, we suggest that ozonesondes always be coupled with a
GPS-enabled radiosonde and that pressure-dependent variables, such as
O3MR, be recalculated/reprocessed using the GPS-measured altitude,
especially when 26 km pressure offsets exceed ±1.0 hPa/±5%. |
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