1. Central Laser Facility, Research Complex, STFC Rutherford Appleton Laboratory, Oxford, OX11 0FA, UK
2. Department of Earth Sciences, Royal Holloway, University of London, Egham, Surrey, TW20 0EX, UK
3. School of Geography, Earth & Environmental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
4. School of Earth Science, University of Bristol, Wills Memorial Building, Bristol, BS8 1RJ, UK
5. National Centre for Earth Observation, Atmospheric, Oceanic and Planetary Physics, University of Oxford, Parks Road, Oxford OX1 3PU, UK
6. Met Office, Fitzroy Road, Exeter, EX1 3PB, UK
7. College of Engineering Maths and Physical Sciences, University of Exeter, Exeter, EX4 4PY, UK