EARLINET and Satellites: Partners for Aerosol Observations Matthias Wiegner Universität München Meteorologisches Institut (Satellites: spaceborne passive radiometry)
Radiative transfer equation RTE
radiance (upward) Radiative transfer equation
source function Radiative transfer equation
optical depth (=0 at top at atmosphere) zenith and azimuth angle of radiance Radiative transfer equation
source function Radiative transfer equation Source Fkt.
Single scattering albedo Radiative transfer equation source function
phase function Radiative transfer equation source function
Radiative transfer equation RTE
Solution Radiative transfer equation Solution
contribution from atmosphere Radiative transfer equation Solution
contribution from surface Radiative transfer equation Solution
phase function, single scattering albedo air molecules, aerosol particles, cloud droplets size, refractive index, shape; height dependent and surface properties as the vertical coordinate is the optical depth, radiance also depends on the extinction coefficient Radiance at satellite depends on Radiance Dependences
optical and microphysical parameters of aerosols radiances at satellite sensor other atmospheric and surface parameters Radiance and aerosols: link Link
optical and microphysical parameters of aerosols radiances at satellite sensor other atmospheric and surface parameters retrieval algorithms Radiance and aerosols: link
optical and microphysical parameters of aerosols radiances at satellite sensor other atmospheric and surface parameters EARLINET- satellite partnership retrieval algorithms calibrated, validated, supplemented partnership
This was the introduction Main topic of my talk How can we establish an „EARLINET-Satellite partnership“? Intro Ende
Calibration and validation of satellite data and retrieval algorithms Supply of complementary information Ground truthing Consequence: Definition of the small workpackage „WP8“ Possible EARLINET contributions Possible contrib. overview
Calibration and validation of satellite data and retrieval algorithms Supply of complementary information Ground truthing Consequence: Definition of the small workpackage „WP8“ Possible EARLINET contributions
Use the EARLINET data-base averaged data (e.g., monthly means) „point by point“ intercomparisons (lidar measurements during an overpass) Ground truth (cal/val)
Validation and calibration of MIPAS Focus on ozone (balloon) No aerosols intercomparions yet Status: waiting for overpasses Examples of partnership Vincenzo Rizi et al., L'Aquila Example (1)
Validation and calibration of SAGE Focus on stratospheric aerosols Regular measurements began in summer 02 Status: ongoing, no final results Examples of partnership Thomas Trickl et al., Garmisch-Partenkirchen
Validation and calibration of MIPAS + GOMOS Focus on water vapour and aerosols Few overpasses, but no aerosol data Status: ongoing (waiting) Examples of partnership Gelsomina Pappalardo et al., Potenza
Examples of partnership MIM in co-operation with : Project for On-Board Autonomy Small Satellite Mission Compact High Resolution Imaging Spectrometer GTCO Validation and calibration of CHRIS Focus on land surfaces Four intensive field experiments scheduled near Gilching
Acquisition mode CHRIS: 18 km swath, 25 m resolution, 19 spectral bands ( µm), along track (5 angles) Time and place May to August 2002 in Gilching Goal Full characterization of surface and atmosphere of exactly the same scene Requirements co-incidence, co-location, very small satellite pixel Examples of partnership
Results/Conclusions Satellite PROBA encountered severe problems: no data were available in summer A new intensive field experiment is uncertain Examples of partnership MIM & GTCO
Calibration and Validation of satellite data and retrieval algorithms Supply of complementary information Ground truthing Consequence: Definition of the small workpackage „WP8“ Possible EARLINET contributions Supplementary Data
Aerosol optical depth Aerosol type Aerosol (vertical) distribution Surface albedo Solar zenith angle Fixed wavelength (532 nm) Relevant Aerosol Parameters Relevant (aerosol) parameters
Vertical aerosol distribution: 5 cases (1) (2) (3) (4) (5) A-Profiles Model calculations
as a function of aerosol optical depth for different aerosol profiles fixed aerosol type Change of Radiance Difference of isotropic radiance at TOA, rel. to „no aerosol“-case Sensitivity profiles
Change of Radiance different aerosol type
Change of Radiance different aerosol type
Change of Radiance different aerosol type
Change of Radiance different aerosol type
Change of Radiance as a function of aerosol optical depth for different 2-layer aerosol profiles fixed aerosol type 2-layer profiles
Change of Radiance different aerosol type
Change of Radiance different aerosol type
Change of Radiance different aerosol type
Change of Radiance different aerosol type
Change of Radiance different layer width
Satellite radiances are significantly influenced by aerosols: -- optical depth -- aerosol type -- aerosol profile Conclusions Simul. Conclusions from simulations
Aerosol vertical distribution is hardly retrievable from satellites Examples of partnership EARLINET can provide this missing information Vertical aerosol distribution is relevant for local energy budget, hydrological cycle, validation of CTM, ecology, and satellite validation as well
TOMS
TOMS
Results/Conclusions Aerosol profiles from more than 20 lidar stations, two times a week and for three years are available. Data and instruments have undergone QA. Benefit of partnership Benefit: Results EARLINET can provide aerosol data that cannot be obtained from passive radiometry. Validation of aerosol retrievals requires a careful selection of time and place, and averaging over reasonable periods. First co-operations are initiated.
The (bright) future Envisat and MSG are still at the beginning of their operation. Benefit of partnership Co-operation requires extra funding !!!! Benefit: Actions Most of the EARLINET-systems stay operational Data archive of EARLINET is available Spaceborne lidar is (almost) ready to launch