IASI cal/val sorties

1. IASI cal/val sorties Jonathan Taylor

2. IASI cal/val plus others Metop was launched on 19th October it contains a range of instruments: AVHRR HIRS AMSU-A – 15 channels from 23-90GHz MHS – 89, 157 and 183GHz channels IASI – 3.3 to 16microns ASCAT – wind speed and direction GOME – vertical profiles of ozone, nitrogen dioxide, water vapour, oxygen / oxygen dimer, bromine oxide and other trace gases, as well as aerosols.

3. Phases of IASI cal/val • UK – up to three flights over water – IASI overpasses are ~0930 and ~2130 local • Kiruna – possibly one flight in Sweden in early Feb, JPT will be mission scientist whenever it happens. • USA – approx 10 flights around Gulf of Mexico and Oklahoma.

4. UK IASI cal/val – 11th to 29th January including weekends! • Satellite overpass – 0930 and 2130 local equator crossing • Take off will be ~115 mins plus transit times before overpass time. • Typical day assuming ~40 min transit: • Miss scientist in looking at weather – 0430 (1630) • Briefing – 0500 (1700) • Take off – 0700 (1900) • Overpass – 0930 (2130) • Landing – 1230 (0030) • Note late landings will be at East Midlands airport with either a recovery to Cranfield or another science flight the following day.

5. Sortie A2 – IASI overpass over ocean (146 only) • Location: Over open ocean ideally along sub satellite track • Weather conditions: Completely cloud free conditions at all altitudes are highly desirable; small amounts of cloud in limited areas are acceptable. • Key instruments: ARIES; AVAPS; SWS; temperature and water vapour sensors. ARIES to view in the nadir during the IASI overpass, a combination of nadir and zenith views at low level. Core chem to have an operator. • Fixed Points: BAe 146 is to follow fixed way points on ground positions located approximately parallel to the satellite track. The way points are • A = °N °W (Northernmost end of straight and level run) • B = °N °W (Middle of run, coincides with overpass time) • C = °N °W (Southernmost end of straight and level run) • 1. Take off, transit to operating area arriving at low level (45 mins) • 2. Start straight and level run from A to C at 100ft (25 mins) • 3. Profile ascent from 50ft to max altitude (e.g. FL320) at 1000ft/min to finish at point C (45 mins) • 4. Start run from C to A; turn (17 mins) • 5. Start run from A to C launching 4 sondes; turn (17 mins) • 6. Start run from C to A to coincide with IASI overpass at B at overpass time launching 4 sondes; turn (17 mins) • 7. Start run from A to C launching 4 sondes; turn (17 mins) • 8. Start run from C to A (15 mins) • 9. Start of profile descent from max altitude to 50ft @ 1000ft/min to finish at point C (35 mins) • 10. Start straight and level run between C and A at 100ft (25 mins) • 11. Transit home (45 mins) • 12. Land (Total sortie time 5:05)

6. Instrument operators • ARIES and SWS • Both instruments must point in the same direction as each other (except during cal) no SWS at night time! • ARIES • At high level mainly Nadir, short view of zenith during one run. • At low level short view to nadir then mainly zenith – important to ensure that Heimann is NOT being calibrated during the short nadir view. • HEIMAN • Miss scientists please ensure Flight Manager performs short cal of Heimann during the 100ft runsn(at start or end) but that this does not clash with the ARIES nadir views.

7. Instruments • Desirable • MARSS/Deimos • Turbulence • FFSSP • 2DP • Heimann • Critical • ARIES • Temp • Humidity • AVAPS • Core chem (manual)

8. Houston Data Processing Exercise • In order to prepare for the Houston campaign we will have a complete practise of the data processing during the latter weeks of Wintex with all processing being completed in room 84A • This will include full flight processing, ARIES, MARSS/Deimos and cloud physics with some radiation modelling as well.

9. Questions & Answers