Summary of Spectral Signatures Labs in Bertinoro 23 Aug – 2 Sep 2004 Paul Menzel NOAA/NESDIS/ORA

1. Summaryof Spectral SignaturesLabs in Bertinoro 23 Aug – 2 Sep 2004Paul MenzelNOAA/NESDIS/ORA

2. Solar (visible) and Earth emitted (infrared) energy Incoming solar radiation (mostly visible) drives the earth-atmosphere (which emits infrared). Over the annual cycle, the incoming solar energy that makes it to the earth surface (about 50 %) is balanced by the outgoing thermal infrared energy emitted through the atmosphere. The atmosphere transmits, absorbs (by H2O, O2, O3, dust) reflects (by clouds), and scatters (by aerosols) incoming visible; the earth surface absorbs and reflects the transmitted visible. Atmospheric H2O, CO2, and O3 selectively transmit or absorb the outgoing infrared radiation. The outgoing microwave is primarily affected by H2O and O2.

3. Solar Spectrum

4. VIIRS, MODIS, FY-1C, AVHRR CO2 O2 H2O O2 H2O H2O H2O O2 H2O H2O CO2

5. MODIS MODIS IR Spectral Bands

6. GOES Sounder Spectral Bands: 14.7 to 3.7 um and vis

7. II II I |I I ATMS Spectral Regions

9. MODIS

11. Ice reflectance High ice cld Midlevel cld Midlevel cld Low water cld

21. Kaolinite montmorillonite Kaolinite montmorillonite

26. Optical properties of cloud particles: imaginary part of refraction index SW & LW channel differences are used for cloud identification {4 m - 11m}, {4.13 m - 12.6m}, and {4.53 m - 13.4m}

27. BT11-BT12 > 0 for ice BT11-BT12 < 0 for volcanic ash Frank Honey 1980s

28. SO2 calculations from F. Prata

30. Fog Detection over Snow Surfaces "Non-detection" of fog over snow surfaces with VIS channels:thick clouds and snow have the same reflectance

32. Emissivity more variable near 3.9 m • Sandy areas appear 5-10 K cooler at IR3.9 than at IR10.8 (at night, dry atmosphere) • Different appearance of land surfaces during daytime, depending on surface type IR3.9 IR10.8 Dry sand: 0.8 0.95 Emissivity as a function of wavelength and surface type

34. Imaginary Index of Refraction of Ice and Dust Dust and Cirrus Signals • Both ice and silicate absorption small in 1200 cm-1 window • In the 800-1000 cm-1 atmospheric window: • Silicate index increases • Ice index decreases • with wavenumber Volz, F.E. : Infrared optical constant of ammonium sulphate, Sahara Dust, volcanic pumice and flash, Appl Opt 12 564-658 (1973) wavenumber

35. Dust IR spectra – green clr sky vs dust particles of different size

36. Dust IR spectra – green clr sky vs dust layers at different heights

37. Fog and Low Stratus

38. Comparison of snow reflectance in VIS and NIR 1.6 channels

41. Ch08 is in the centre of the O3 absorption band around 9  Energy spectrum Source:EUMETSAT Ch08

42. Signals from lower parts of troposphere; But: Secondary maximum from higher than 100 hPa Weighting functions Source:EUMETSAT Figure 3c

43. AIRS radiance changes (in deg K) to atm & sfc changes 43

44. 12 m 9 m Inferring surface properties with S-HIS high spectral resolution data - Note the large change, especially for bare soil, in surface emissivity between 960 and 1060 cm-1. The HES minimum mission would not cover both regions. 44 Pure Vegetation 1.0 Aircraft S-HIS LSE S-HIS OBS Bare Soil 0.85 Wavenumber (cm-1)