Radiation session report Chair: Shulin Liang, Mark Chopping Rapporteur: Eric Vermote Participants: C

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Radiation session reportChair Shulin Liang,
Mark ChoppingRapporteur Eric VermoteParticipan
ts Crystal Schaaf, Robert Friedel,Kenlo Nishida,
Gabriela Shaepman-Strub,Youngryel Ryu, Hirofumi
Hashimoto, Steve Klooster, Craig Smith, Jicheny
Liu

• Product Overview Presentations focus on
  Algorithm-Sensors/Validation.
• Surface directional reflectances (E. Vermote)
• MODIS/MISR/POLDER/ETM/MERIS/VEGETATION/SeaWIFS/AV
  HRR
• Validation RT Validation AERONET
• Albedo (C. Schaaf)
• MODIS/MISR/POLDER/CERES/METEOSAT/MSG
• BSRN Sites (9)
• Radiation PAR/Radiation Budget (S. Liang)
• MODIS and Geostationnary based
• Validation on FLUXNET sites
• Surface Temperature emissivity (ESDR white paper
  S. Liang)
• MODIS/ASTER Ambitious requirements / Difficulty
  in Validation
• ESDR White Papers a step towards Measurement
  Teams at NASA LCLUC Web Site

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Radiation session discussions
Product validation AERONET is crucial to the
surface directional reflectance
validation AERONET is also needed when comparing
to ground measurements (affected by atmospheric
effects) AERONET and Albedo measurements should
be collocated. Recommendation to ensure that
AERONET continues (through VIIRS) Currently we
are restricted to 9 BSRN sites for Albedo.
Recommendation to improve data protocol at
FLUXNET and BSRN (up/down). Acquiring high
spatial resolution data (c. 30m), on continuous
basis for validation sites (Albedo sites in
priority AERONET sites). Recommendation to
target all high res sensors for these
sites Validation needs to characterize spectral,
temporal, spatial error Consistent high quality
thermal atmospheric profile are needed to assess
atmospheric correction in the thermal (following
the AERONET example for surface directional
reflectance) e.g. lidar profiles Thermal
products need the same radiative transfer rigor
as shortwave
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Radiation session /Discussions

• Product Intercomparison
• Intercomparison of performance of the surface
  directional reflectance products over the AERONET
  sites MODIS/MERIS/Vegetation (supported in
  collaboration with F. Baret and M. Leroy). This
  needs to be extended to other sensors e.g.
  POLDER/MISR (to be supported)
• Intercomparison of Albedo products
  (MODIS/MISR/METEOSAT completed, other sensors to
  be analyzed) following the analysis protocol used
  in the LAI product intercomparison.

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Radiation session /Discussions

• Product fusion
• Fusion of geostationnary satellite data with
  polar orbiter data will improve the usefulness
  and quality of the albedo, radiation and LST
  (diurnal cycle important for modellers).
• Product producers and users
• Most Users are not familiar with the issues of
  surface radiation product quality
• Need to build a better informed user community
  and have better interactions with them (listing
  users and requirements on LPV).
• Need to demonstrate the impact of improved
  products to users (e.g. AVHHR albedo vs
  MODIS/MISR) preferably with the associated
  improvement to the science
• Get explicit user requirements will help make
  the case for investment in this area (e.g. is
  longwave surface upwelling radiance needed or
  Emissivity and temperature?)
• Obstacles remain in obtaining coincident data
  from different systems
• Need Easier Data Access - different systems
  have different access policies
• In some cases not obvious how to even get the
  data
• Future missions
• Overlap is crucial (2 years of operation) to
  ensure continuity (e.g MODISgtVIIRS).
• Continuous high spatial resolution (30m) is
  needed in support of validation (spatial
  heterogeneity)

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Summary Recommendations

• Recommendation to ensure that AERONET continues
  (through VIIRS) (Funding agency)
• Recommendation to improve FLUXNET/BSRN data
  protocols to match albedo validation needs.
• Recommendation to target all high res sensors for
  the validation (Albedo in priority AERONET
  sites) (Data providers)
• Recommendation for products intercomparisons
  (Product developers)