1. Aerosol Retrieval Research Algorithm for TEMPO
TEMPO Aerosol Workshop
11 Sept. 2017
Aerosol Retrieval Research Algorithm for TEMPO
Jun Wang, Weizhen Hou, Scott Janz, Jay Al-Saadi,
Xiong Liu, Kelly Chance, Omar Torres

2. Brief History of Geo. Weather Satellite
Himawari-8
Latest geo weather, JAXA
Launched 10/7/2014
GOES-A/1
1st geo for environment
GOES-1, launched 10/16/1975, NASA
Better imager
Advanced Himawari
Imager (AHI)
16 bands
3 vis. , 1 km & .5 km
4 NIR, 2 km
9 TIR, 2 km.
10 minutes/full disk
1st geo., launched in 02/14/1963,
a communication sat., NASA
Syncom I
Spin Scan Radiometer (VISSR)
μm, 1 km
μm, 9 km

3. Brief History of Geo. Aerosol/ Air Pollution Satellite
Launch 2020?
Brief History of Geo. Aerosol/ Air Pollution Satellite
GOES-R
2016
Imager  Spectrometer
GOCI
6/10/2010I
Fishman et al., 2012
Lahoz et al., 2012
Schmit et al., 2017
Lee et al., 2010.
RSE
6 visible
2 NIR
GOES-2
MSG, 8/28/2002
12 channels
2 visible
Fraser, Kaufman, Mahoney, 1984, AE

4. Hyperspectral GEO Era is coming!
TEMPO
GOES-R
Sentinel-4
MSG
GEMS
Himawari
Courtesy Jhoon Kim,
Andreas Richter
Policy-relevant science and environmental services enabled by common observations
Improved emissions, at common confidence levels, over industrialized Northern Hemisphere
Improved air quality forecasts and assimilation systems
Improved assessment, e.g., observations to support the United Nations Convention on Long Range Transboundary Air Pollution

5. Most aerosol algorithms use data from radiometers
Wang et al., 2014, JQSRT

6. Aerosol properties retrieved from current sensors
Hou et al., 2017

7. Past work done using spectral fitting, primarily in the infrared spectrum
ACP, 2013
(sulfate acid, ammonium sulfate, dust, smoke, volcanic ashes)

8. Hyperspectral remote sensing of aerosols in the shortwave spectrum?
Need to characterize the surface reflectance spectra.
TOA spectral variation more or less reflects surface spectra except in shorter wavelengths ( <~500 nm)
AOD=1

9. TEMPO/GEO-TASO

10. What have been done?
A framework for hyperspectral simultaneous retrieval of aerosol & surface properties
Surface reflectance spectra can be reconstructed with 6 principal components. (PCs)
Analytically compute Jacobians of TOA reflectance w.r.t. each surface reflectance PC.
Aerosol information content analysis for hyperspectral satellite sensor in visible
Common bands exist for aerosol retrieval over a wide range of surface conditions
Feasibility study of retrieving both aerosol & surface from geostationary sensor
This feasibility is shown when multiple measurements from geo sensor are used
Self-adjustable algorithm for aerosol is proposed for geostationary sensor

11. Information content analysis results for individual observation (retrieving 1 or 2 aerosol parameter together with w)
Refff
Reffc
50 green spectra from vegetated spectral dataset and 10 AOD (τa = 0.05, 0.1, 0.15, 0.2, 0.3,0.4, 0.5, 0.6, 0.8, 550nm) are considered for individual observation, then calculate the averaged DFS and standard deviation (error bar).

12. Information content analysis results for multiple observation (retrieving 3 aerosol parameter together with w)
50 green spectra from vegetated spectral dataset and 10 AOD (τa = 0.05, 0.1, 0.15, 0.2, 0.3,0.4, 0.5, 0.6, 0.8, 550nm) are considered for multi-observations.
3 multi-observations means selecting the 120 combinations of 3 AOD from 10 AOD,then calculate the averaged DFS and standard deviation.

13. Test with GEO-TAOS data during Korus-AQ

14. Study region of GeoTAOS (May 17, 2016, UTC)

15. True-color images river forest urban
The matching regions of 6 flights from May 16 to May 18, 2016

16. Solar Zenith Angles
Two different times

17. Viewing Zenith Angles
flight
direction

18. GEO-TASO Radiance at 340 nm

19. GEO-TASO Radiance at 380 nm

20. Summary
The theoretical basis for TEMPO research algorithm for aerosol retrieval is established.
Progress of using real data is on the way…

21. Thank you !

22. Aerosol Index

23. GEO-TASO observation in Korus-AQ