© Crown copyright Met Office An update on plans for CAVIAR field campaigns Stuart Newman NPL, 2 June 2008

© Crown copyright Met Office Observations versus simulations Methodology for Camborne field campaign  Accurate interferometer measurements combined with a well- characterised atmospheric state are essential requirements  Need frequent dropsonde profiling (temperature and water vapour) in addition to Camborne radiosonde launches  Need ARIES and TAFTS to view both upwelling and downwelling radiances at a series of heights in the atmosphere NPL FTS and radiosondes at Camborne Surface temperature and emissivity from runs at low level

© Crown copyright Met Office Flying discussion 16/4/2008 Orientation of straight-and-level runs constrained slightly by military “danger areas” off Cornish coast from Google Maps Camborne Danger Areas Runs of 40 nautical miles (74 km) approximate to 10 minutes at ft

© Crown copyright Met Office “Balloon chasing” Camborne station staff have agreed to launch balloons according to our requirements either side of the 1115 UTC midday ascent FAAM pilots to perform polygon ascent to “chase” balloon Intercomparison of sonde and aircraft water vapour instruments important for understanding errors

© Crown copyright Met Office Water vapour instrumentation FAAM 146: Chilled mirror dew point (2) Total water Lyman-  Fluoresence water vapour sensor SAW hygrometer (Cambridge) CVI hygrometer Dropsonde dew point Radiosondes:Dew point sensor Camborne:GPS water vapour Surface dew point Note also that Met Office MICROTOPS aerosol optical thickness sun photometer will be deployed at Camborne, other instruments to be confirmed

© Crown copyright Met Office Campaign logistics Communications between FAAM 146 and NPL / Camborne best achieved by use of the aircraft satellite phone ( with the aircraft is also possible) Desirable to maximise science time by refuelling at a local airport before return transit to Cranfield base (e.g. Newquay or Cardiff)

© Crown copyright Met Office Jungfraujoch

© Crown copyright Met Office Jungfraujoch key points Advantages for FAAM 146 to be based in Switzerland, Geneva or Sion as candidate airfields Minimum altitude for FAAM aircraft is 2000 feet above terrain (Jungfraujoch station at feet) Proposal for aircraft to follow a stepped climb, with lower altitude flying possible in valleys (surface emissivity measurements require flying as low as possible) Careful planning required for busy airspace Nearest radiosonde observations need to be identified (Bern…)

© Crown copyright Met Office Questions and answers