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| Titel |
Measurements of Humidity in the Atmosphere and Validation Experiments (MOHAVE)-2009: overview of campaign operations and results |
| VerfasserIn |
T. Leblanc, T. D. Walsh, I. S. McDermid, G. C. Toon, J.-F. Blavier, B. Haines, W. G. Read, B. Herman, E. Fetzer, S. Sander, T. Pongetti, D. N. Whiteman, T. G. McGee, L. Twigg, G. Sumnicht, D. Venable, M. Calhoun, A. Dirisu, D. Hurst, A. Jordan, E. Hall, L. Miloshevich, H. Vömel, C. Straub, N. Kämpfer, G. E. Nedoluha, R. M. Gomez, K. Holub, S. Gutman, J. Braun, T. Vanhove, G. Stiller, A. Hauchecorne |
| 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 ; 4, no. 12 ; Nr. 4, no. 12 (2011-12-01), S.2579-2605 |
| Datensatznummer |
250002142
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| Publikation (Nr.) |
 copernicus.org/amt-4-2579-2011.pdf |
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| Zusammenfassung |
The Measurements of Humidity in the Atmosphere and Validation Experiment
(MOHAVE) 2009 campaign took place on 11–27 October 2009 at the JPL Table
Mountain Facility in California (TMF). The main objectives of the campaign
were to (1) validate the water vapor measurements of several instruments,
including, three Raman lidars, two microwave radiometers, two
Fourier-Transform spectrometers, and two GPS receivers (column water), (2)
cover water vapor measurements from the ground to the mesopause without
gaps, and (3) study upper tropospheric humidity variability at timescales
varying from a few minutes to several days.
A total of 58 radiosondes and 20 Frost-Point hygrometer sondes were
launched. Two types of radiosondes were used during the campaign. Non
negligible differences in the readings between the two radiosonde types used
(Vaisala RS92 and InterMet iMet-1) made a small, but measurable impact on
the derivation of water vapor mixing ratio by the Frost-Point hygrometers.
As observed in previous campaigns, the RS92 humidity measurements remained
within 5% of the Frost-point in the lower and mid-troposphere, but were
too dry in the upper troposphere.
Over 270 h of water vapor measurements from three Raman lidars (JPL and
GSFC) were compared to RS92, CFH, and NOAA-FPH. The JPL lidar profiles
reached 20 km when integrated all night, and 15 km when integrated for 1 h. Excellent agreement between this lidar and the frost-point hygrometers
was found throughout the measurement range, with only a 3% (0.3 ppmv)
mean wet bias for the lidar in the upper troposphere and lower stratosphere
(UTLS). The other two lidars provided satisfactory results in the lower and
mid-troposphere (2–5% wet bias over the range 3–10 km), but suffered from
contamination by fluorescence (wet bias ranging from 5 to 50% between 10 km and 15 km), preventing their use as an independent measurement in the
UTLS.
The comparison between all available stratospheric sounders allowed to
identify only the largest biases, in particular a 10% dry bias of the
Water Vapor Millimeter-wave Spectrometer compared to the Aura-Microwave Limb
Sounder. No other large, or at least statistically significant, biases could
be observed.
Total Precipitable Water (TPW) measurements from six different co-located
instruments were available. Several retrieval groups provided their own TPW
retrievals, resulting in the comparison of 10 different datasets. Agreement
within 7% (0.7 mm) was found between all datasets. Such good agreement
illustrates the maturity of these measurements and raises confidence levels
for their use as an alternate or complementary source of calibration for the
Raman lidars.
Tropospheric and stratospheric ozone and temperature measurements were also
available during the campaign. The water vapor and ozone lidar measurements,
together with the advected potential vorticity results from the
high-resolution transport model MIMOSA, allowed the identification and study
of a deep stratospheric intrusion over TMF. These observations demonstrated
the lidar strong potential for future long-term monitoring of water vapor in
the UTLS. |
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