Johannes Schmetz

1
The Need for Hyperspectral Sounders in
Geostationary OrbitInternational Perspective

• Presented by
• Johannes Schmetz
• EUMETSAT

2
The Coordination Group for Meteorological
Satellites (CGMS) has recognised the need for
hyperspectral sounding from geo-stationary orbit

• Action 31.36 from CGMS in 2003
• CGMS satellite operators to inform CGMS 32
• on plans to achieve the goal that all
• geostationary imagers should be upgraded to
• at least the level of SEVIRI by the 2015
• timeframe and frequent IR sounding should
• be made by high resolution spectrometers
• within the same timeframe.

3
WMO Commission for Basic SystemsExpert Team on
Evolution of the global observing system (1)

• From Report of the 4th Session, Geneva, 7-11 July
  2008,
• chaired by Dr. John Eyre
• GEO Sounders
• All meteorological geostationary satellites
  should be equipped with hyperspectral infrared
  sensors for frequent temperature/humidity
  sounding as well as tracer wind profiling with
  adequately high resolution (horizontal, vertical
  and time).

4
WMO Commission for Basic SystemsExpert Team on
Evolution of the global observing system (2)

• Quote from commentary in report of the 4th
  Session, Geneva, 7-11 July 2008
• Instruments of this type in geosynchronous orbit
  are high priority
• enhancements to the Global Observing System (GOS)
  
• based on the experience gained from classical IR
  sounding from
• GEO satellites and from hyperspectral Infrared
  sounding from LEO
• satellites, the impact of hyper-spectral sensors
  on GEO satellites is
• expected to be very positive.
• . it would be useful to proceed with a direct
  demonstration mission
• based e.g. on the USAs GIFTS development in
  advance of the
• planned operational series.

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Hyperspectral InfraRed Sounding (IRS) on
Meteosat Third Generation (MTG)
IRS high level user needs

• First priority is on operational meteorology NWP
  and NWC
• IRS will also support in synergy with the other
  MTG candidate missions emerging applications as
  chemical weather and air quality.
• Priorities of IRS applications
• Time sequences of small scale (horizontally/vertic
  ally) water vapour structures in support of
  regional/global NWP and NWC
• Atmospheric dynamic variables with improved
  height information (e.g. wind profile)
• Monitoring of instability / forecasting onset of
  convection / early warning of convective
  intensity
• Cloud microphysical structure and temporal
  evolution
• Support to air quality applications (as emerging
  application)

6
MTG-IRS will detect moisture changes and
gradients
MTG-IRS mission will give new information on
horizontal and vertical gradients of moisture,
wind and temperature.
7
Case study 3rd December 2003 Montpellier, France
ALADIN (10 km res) forecasts up to 9h were
reasonably good -gt ALADIN model physics
already capable for predicting heavy precipitation
Beyond 9h lead time ALADIN failed predicting key
elements (place and structure of convergence
line) accurate enough to depict the floods
hitting the town of Montpellier. -gt
Better knowledge on initial state could have
significantly improved precipitation forecasts
and warnings
9UTC RADAR and 10m wind 9h ALADIN forecast
12UTC RADAR and 10m wind 12h ALADIN forecast
Breakthrough in precipitation forecast is
expected with the IRS information Assimilated in
advanced non-hydrostatic regional models as AROME
in France
8
Conclusions from J.N. Thepaut (ECMWF) at 3rd MTG
Users Consultation Workshop, December 2007

• MTG-IRS mission is justified for global NWP
• as an initial step towards a full GEO
  constellation?
• because of the high temporal, horizontal and
  vertical resolution
• Going from 6 hour ( METOP/NPOESS) to 1 hour
  repetition time
• Better constraint on humidity structures that are
  relevant to analysis in high resolution NWP
  models (10km global in 2015-2020)
• assuming the height assignment problem for water
  vapour winds is solved, thanks to high spectral
  resolution of the instrument
• Quantitative assessment difficult with
  state-of-the-art data assimilation and
  observations
• REGIONAL NWP remains the main driver for this
  mission
• ADDED by JS for this talk Better model physics
  is needed to fully utilise humidity information
  gt better cloud formation in model gt better
  precipitation f/c

9
CGMS and WMO have clearly recognised the need
for hyperspectral sounding from geo-stationary
orbit (2)

• Recommendation 36.15 from CGMS in 2008 reads
• In view of the most recent studies showing the
  great benefit of hyperspectral sounding to
  predict the onset of severe weather with much
  longer lead times and the potential for climate
  monitoring and improved satellite
  intercalibration, CGMS sees a firmly established
  need to fly hyperspectral sounders on
  next-generation geostationary satellites.