© crown copyright met office overview of camborne field campaign stuart newman imperial college, 16...
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© Crown copyright Met Office
Overview of Camborne field campaignStuart Newman
Imperial College, 16 December 2008
© Crown copyright Met Office
CAVIAR field campaign #1Overview of Camborne campaign
CAVIAR work package 3.3 Campaign centred on Camborne (Cornwall), 13 August to 25 September 2008
Site provides measurements of meteorological variables and radiosonde balloon profiles of temperature and water vapour
FAAM aircraft flew in conjunction with measurements of NPL’s high resolution solar-tracking FTS on the ground
As a coastal site can exploit downward pointing interferometer measurements from the FAAM aircraft over the sea (homogeneous surface emission) as well as upward pointing measurements
Campaign #2 (Jungfraujoch Swiss Alps scientific station, Sept 2009) will be complementary with ≈ tenth column water vapour c.f. Camborne
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FAAM BAe 146-301 capability
Blister containing ARIES and TAFTS
ARIES interferometer (Bomem MR200)Spectral range 550-3000 cm-1
TAFTS interferometer (Imperial College)Spectral range 80-800 cm-1
Both instruments view upwelling and downwelling radiances
• Dropsondes
• Core chemistry (ozone and CO)
• Temperature and humidity probes
• Multi-spectral radiometer (solar)
• Microwave radiometers
• Particulates (aerosols and cloud particles)
• Winds (and more…)
Endurance 5½ hoursAltitude 20 m – 10.5 km
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Camborne radiosonde station
• NPL solar-tracking FTS based on site
• Regular radiosonde ascents (midday) plus extra ascents on request
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Observations versus simulationsMethodology for Camborne field campaign
NPL solar-tracking FTS at CamborneSurface temperature and emissivity from
runs at low level
Intensive profiling
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Summary of flights
• British “summer” weather in August and September not always conducive to clear sky conditions!
• Flights conducted on five separate days
• One day (22/8) included a double flight with refuel
• Two flights were aborted due to excessive cloud
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Ground-based data
• NPL solar-tracking Fourier transform spectra
• Radiosonde balloons
• GPS integrated water vapour
• Lidar backscatter
• Microwave T, q retrievals
• MICROTOPS sun photometer
6:00 8:00 10:00 12:00 14:00 16:00 18:00
U.T. / hh:mm
12/08/2008
13/08/2008
19/08/2008
22/08/2008
18/09/2008
23/09/2008
24/09/2008
Dat
e / d
d:m
m:y
yyy
CAV33: Duration of NPL Camborne Ground Based Measurements
Volume of Reading University Mircotops Data
0
10
20
30
40
50
60
07/23/2008 08/07/2008 08/12/2008 08/13/2008 08/19/2008 08/22/2008 09/18/2008 09/23/2008
Date / dd/mm/yyyy
Num
ber o
f Mea
surm
ents
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Campaign data cont.
• Met Office and ECMWF analyses (model fields)
• MetOp satellite data
• Aircraft instrument data
• See http://badc.nerc.ac.uk/data/caviar/
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B396 flight (19 Aug 2008)
• Persistent boundary layer cloud over Camborne, with some clear sky breaks
• 10 dropsondes released
• 12 aircraft runs over Camborne at different altitudes
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B397 flight (22 Aug 2008)
• Occasional broken boundary layer cloud over Camborne, with good clear sky breaks
• Double flight with refuel
• 17 dropsondes released
• 22 aircraft runs over Camborne at different altitudes
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B400 flight (18 Sep 2008)
• Very good clear sky conditions
• Flight included “chase” of radiosonde for water vapour intercomparison
• 6 dropsondes released
• 8 aircraft runs over Camborne at different altitudes
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B400 flight (18 Sep 2008)
• Best clear sky conditions encountered – no need for cloud hole hunting
• ARIES and TAFTS seemed to operate well
• Reasonably stable atmospheric structure
• High aerosol loading but IR measurements insensitive to this
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ARIES data from 3 altitudes
residual differences (obs-calc) / K
ARIES nadir brightness temperatures
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TAFTS summary
Date Flight no. Meteorology Useful science
TAFTS performance
13/08/08 B394 N/A Test flight
19/08/08 B396 Persistent broken StCu, increasing late on
Yes Partial laser up to 1.5hrs
22/08/08 B397/398 Some broken StCu Yes No laser
11/09/08 B399 Too cloudy (Aborted) Good
18/09/08 B400 Excellent Yes Excellent
23/09/08 B404 Too cloudy (Aborted) Good
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TAFTS example data Comparison with simulation
Upwelling
Downwelling
Local OAT
Simulation (both UW
and DW)
Ch0
Ch1
Run 4, 34kft (7mins of data) against dropsonde #3
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NPL solar-tracking FTS High resolution spectra at IR/solar wavelengths
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Summary and future work
• Three successful flights were completed over Camborne in Summer 2008
• Comprehensive data set combining radiance observations and measurements of the atmospheric state
• Ongoing work to derive best estimates for temperature and water vapour profiles for case studies
• Aircraft interferometer data quality looks good for B400
• Future work: corroborate results by comparing with other flight days, and intercompare results from ARIES, TAFTS and NPL FTS
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Questions and answers
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North South
ARIES retrieval (B400)
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B400 case for initial analysis
FL340 (250 hPa)
FL290 (314 hPa)
FL145 (583 hPa)