Overview of Camborne, UK and Jungfraujoch, Switzerland Field Campaigns CAVIAR Annual Meeting 15 th Dec 2009, Abingdon Marc Coleman, Tom Gardiner, Nigel.

Overview of Camborne, UK and Jungfraujoch, Switzerland Field Campaigns

CAVIAR Annual Meeting

15th Dec 2009, Abingdon

Marc Coleman, Tom Gardiner, Nigel Swann (NPL)

Liam Tallis (University of Reading)

Stuart Newman, Jonathan Taylor (Met Office)

Paul Green, Ralph Beeby, Juliet Pickering (Imperial College)

+ FAAM team

Monday, April 10, 2023

2

Background• Field measurements of water vapour continuum

required to help validate modelling work• Key instruments radiometrically calibrated at NPL

prior to each measurements campaign– Two instruments for airborne measurements (mounted on

the FAAM BAe146 aircraft)– One instrument for ground-based measurements

• Two measurement campaigns carried out– Camborne, UK: Low altitude – wet– Jungfraujoch, Switzerland: High altitude – dry

• Carried out at high and low altitude sites so that it is possible to access the centre of water bands, which facilitates characterisation of the dependence of the continuum on water abundance


3

Key Instruments(1): TAFTS and ARIES

• Both instruments passive Fourier transform infrared (FTIR) spectrometers

• TAFTS (Imperial College)– Measures difference

spectrum between nadir and zenith views

– 4 internal black bodies. One warm and one cold for each view

• ARIES (Met Office)– Can measure nadir and

zenith (not a difference measurement)

– Internal black bodies

TAFTS – tropospheric airborne Fourier transform spectrometer

ARIES – airborne research interferometer evaluation system


4

Key Instruments(2): NPLs High Resolution FTIR

• Instrument is a Bruker IFS125M FTIR augmented with NPL optics

• Unlike TAFTS and ARIES system is active– Uses sun as a light source– Interfaced with a solar tracker to track sun

• Capable of resolutions of up to 0.0035 cm-1

• Broad spectral coverage

Solar tracker


5

Radiometric Calibration of TAFTS & ARIES

• TAFTS and ARIES calibrated using a custom built black body – CAVIAR Black Body (CBB)– -80 to +40°C temp. range– Traceable to the primary radiometer (method by which the Candela is realised

in the UK)

Grooves for ethanol coolant

CAVIAR Black Body (CBB)

TAFTS


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Radiometric Calibration of NPL FTIR

• For active FTIR use NPLs ultra high temperature black body– ~3000K– Used to realise the primary radiance scale in the UK– Traceable to the primary radiometer (as is the CBB)

• All three instruments traceable, therefore have comparability


7

Facility for Airborne Atmospheric Measurements (FAAM)

• After calibration TAFTS & ARIES re-installed on FAAM plane for first CAVIAR field trial

• Also on-board:– Chilled mirror dew

point– Total water Lyman-

– Fluorescence water

vapour sensor– SAW hygrometer– CVI hygrometer– dropsondes

Rosemount temp probes

Cloud Physics Probes


SHIMS

SHIMS

Rearward and Downward Video Cameras

Short-wave spectrometer (0.3 – 1.7µm)

Microwave radiometers

Aries Interferometer (3-16 µm)

TaftsInterferometer (10 to 125 µm)

Broad band radiometers

Lidar Dropsondes




SHIMS

SHIMS







Lidar Dropsondes




SHIMS

SHIMS







Lidar Dropsondes


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Camborne Field Trial• August – September 2008• FAAM flew out of Cranfield base• NPL FTIR & Reading

MICROTOPS (aerosol optical thickness) based at Camborne Met Office site

• Other relevant instrumentation at Camborne– Routine sonde launches from

Camborne at 11:15 and 23:15 U.T.

• Additional launches made on ‘good’ measurement days

– GPS water vapour column– Laser cloud base and visibility– Surface dew point

NPL FTIR

Sonde launch


9

FAAM Flights over Camborne• South east inaccessible due to military

operations• Operated mainly starting from north and

west– Allowed runs at low level over sea providing

surface temperature and emissivity data

• Runs of 40 nautical miles lasted ~10min at 10,000 feet

• Polygon FAAM accents (“balloon chasing”) will allow comparison between sonde and FAAM water vapour measurements


10

Camborne Water Vapour Profiles

• Aircraft straight and level runs divided into three sections: Camborne and northern and southern areas over ocean

• (Corrected) radiosonde and dropsonde profiles were used as the nearest coincident measurements of temperature and water vapour

• ECMWF analysis and forecast fields were used to account for changes in air mass with time and distance, allowing the sonde profiles to be modified accordingly

• Similar process is being undertaken for the Jungfraujoch measurements


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Camborne Flights

• A typically “British” summer!• On 22nd Aug a double flight was possible, although throughout the day

broken cloud caused occasional obstruction• However, 18th Sep saw excellent clear sky conditions, hence so far

analysis has focussed on this day• nb. silver lining to fewer flights than planned was that additional flights

were available for the Jungfraujoch field trial

= aborted flight

= successful flight

AU G U S T 2008Sunday Monday Tuesday Wednesday Thursday Friday Saturday

1 2

3 4 5 6 7 8 9

10 11 12 13 14 15 16

17 18 19 20 21 22 23

24 25 26 27 28 29 30

31 Notes:

© 2007 Vertex42 LLC http ://w w w .vertex42.com

S M T W Th F Sa1 2 3 4 5

6 7 8 9 10 11 1213 14 15 16 17 18 1920 21 22 23 24 25 2627 28 29 30 31

J uly 2008S M T W Th F Sa

1 2 3 4 5 67 8 9 10 11 12 1314 15 16 17 18 19 2021 22 23 24 25 26 2728 29 30

September 2008

S E PTE M B E R 2008Sunday Monday Tuesday Wednesday Thursday Friday Saturday

1 2 3 4 5 6

7 8 9 10 11 12 13

14 15 16 17 18 19 20

21 22 23 24 25 26 27

28 29 30

Notes:


S M T W Th F Sa1 2

3 4 5 6 7 8 910 11 12 13 14 15 1617 18 19 20 21 22 2324 25 26 27 28 29 3031

August 2008S M T W Th F Sa

1 2 3 45 6 7 8 9 10 1112 13 14 15 16 17 1819 20 21 22 23 24 2526 27 28 29 30 31

October 2008


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Jungfraujoch Field Trial

• NPL FTIR (1.8 tonne of equipment!) transported to Jungfraujoch research station (~3500m above sea level)

• FAAM plane based in Basel

Jungfraujoch research station

(NPL FTIR)

JungfrauMönch

Eiger

FAAM in Basel


13

FAAM Flights• Used glacier on approach for

uniform surface temperature and emissivity measurements

• Runs at 15,000 to 35,000 feet• Spiral ascents over the

Jungfrau• Dropsondes from a high level


14

Jungfraujoch Research Station

• NPL FTIR & MICROTOPS installed at research station. Solar tracker mounted on balcony to face south looking down valley

• Other data available from the station– Liege FTIR (part of NDACC)

– LIDAR (unfortunately v.little coincidence with flights)

– Sonde launches from Payerne

– GPS water vapour


15

Example Effect of High Altitude

• Camborne and Jungfraujoch spectra from NPL FTIR show effect of measuring from high altitude

8000 8200 8400 8600 8800 9000 9200 9400 9600 9800

0

0.05

0.1

0.15

0.2

0.25

Wavenumber / cm-1

FT

IR r

espo

nse

/ a.u

.

CamborneJungfraujoch


16

Jungfraujoch Flights

• 9 flights, compared to 3 in Camborne, justified spending the summer out of Britain!• Sonde launch from Payerne on evening of 20th Jul

– Will allow for comparison against FAAM instruments

• MetOp overpass on morning of 27th Jul• Dates when there was the most coincident air- and ground-based measurements with

the smallest amount of cloud interruption were– 19th, 26th, 27th Jul and 4th Aug – Analysis initially to focus on 27th July as measurement conditions very good (i.e. very clear) and

coincides with MetOp overpass

J U L Y 2009Sunday Monday Tuesday Wednesday Thursday Friday Saturday

1 2 3 4

5 6 7 8 9 10 11

12 13 14 15 16 17 18

19 20 21 22 23 24 25

26 27 28 29 30 31

Notes:


S M T W Th F Sa1 2 3 4 5 6

7 8 9 10 11 12 1314 15 16 17 18 19 2021 22 23 24 25 26 2728 29 30

J une 2009S M T W Th F Sa

12 3 4 5 6 7 89 10 11 12 13 14 1516 17 18 19 20 21 2223 24 25 26 27 28 2930 31

August 2009

AU G U S T 2009Sunday Monday Tuesday Wednesday Thursday Friday Saturday

1

2 3 4 5 6 7 8

9 10 11 12 13 14 15

16 17 18 19 20 21 22

23 24 25 26 27 28 29

30 31 Notes:


S M T W Th F Sa1 2 3 4

5 6 7 8 9 10 1112 13 14 15 16 17 1819 20 21 22 23 24 2526 27 28 29 30 31

J uly 2009S M T W Th F Sa

1 2 3 4 56 7 8 9 10 11 1213 14 15 16 17 18 1920 21 22 23 24 25 2627 28 29 30

September 2009

= aborted flight

= successful flight


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Summary

• Achieved traceable, radiometric calibration of TAFTS, ARIES and NPL FTIR– Custom built CAVIAR BB will be available for future

calibrations

• Two successful field trials at a low and high altitude sites– Bad weather days in Camborne off-set with better than

expected weather in Jungfruajoch. So overall we posses a large body of data

– Have identified key days from each field trial for focussed analysis

• Instrument intercomparison• In support of modelling work

Overview of Camborne, UK and Jungfraujoch, Switzerland Field Campaigns CAVIAR Annual Meeting 15 th Dec 2009, Abingdon Marc Coleman, Tom Gardiner, Nigel.

Documents

faam water vapour measurements

faam team slide

jungfraujoch measurements

faam flights

water abundance slide

basel slide

high level slide

camborne flights