210 likes | 226 Views
Cutting-edge spectrometer for atmospheric research results from test-flight series using AERONET-like and AATS-like capabilities. Gather data on AOD, size distributions, and more. Collaboration with key institutions. Future missions planned. Funded by NASA, DOE & more.
E N D
4STAR: Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric ResearchResults from Test-flight Series A collaboration involving:
AERONET-like capability • Ground-based direct beam + sky scanning yields column-integrated properties: • AOD • Size distributions • Single-scattering albedo • Asymmetry parameter • Sphericity • Cloud OD 4STAR: Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research AATS-like capability: AOD at 13 wavelengths H2O horizontally and vertically resolved 4STAR:
Meet the family… AATS-6 (1985-2001) AATS-14 (1996- 4STAR (2012-
Anticipated 4STAR data products: • Solar Direct Beam • Atmospheric Transmittance • Aerosol Optical Depth and Ångstrom exponent • Aerosol Extinction (via aircraft vertical profiling) • Gases: H2O, O3, NO2, CO2 (column and in profile) • Angularly-resolved sky radiance inversions • Scattering phase function, asymmetry parameter • Aerosol size distributions, fine/coarse mode fraction • Aerosol sphericity • Aerosol absorption • Zenith radiance cloud retrievals • Cloudy/clear transition zone (Marshak, Chiu) • Cloud Optical Depth, Droplet effective Radius (with auxilliary measurements, Barker et al.) • Water vapor, liquid water, ice water fractionation (Daniels et al.)
4STAR-Ground AERONET Cimel Jens Redemann Roy Johnson
Sun Photometer Inter-Comparison Experiment Mauna Loa, Aug. 24 - Sep. 2 2008 AATS-14 Prede 3 AERONET Cimels 4STAR
max alt 5.7 km • 3 flights in Sep 2010: • Pilots only: Airworthiness certification • Science ops: Pasco, WA to San Jose, CA • Science ops: San Jose local • 2 flights in April 2011: Pasco - Eastern WA, Idaho 12
Vertical profile of optical depth(normalized to top of layer) l (nm) 9/28/2010 SJC ~10 am 13
Final flight series (late Aug 2011) max alt 5.7 km Langley Calibration Science Example Test Capability FORJC Testing 14
Sensitivity of retrievals to stray light close to sun (3-6°) 15% 20%
Sensitivity of retrievals to stray light close to sun (3-6°) Poster A11H-0196, Kassianov et al.
Next steps… • FY12: bring 4STAR to full science capability • Improve FOV uniformity of sun optics • Improve scattering isolation of sky optics • Apply correction of stray light inside spectrometer • Hardening and retrieval algorithms • DOE/ARM Mission on G-1, Cape Cod, July 2012 & Feb 2013 • Possible Mission on NASA DC-8,(SEAC4RS, Asia), Aug-Sep 2012 Funding: NASA, DOE ARM, BMI, PNNL