2.  Introduction  Surface Albedo  Albedo on different surfaces  Seasonal change in albedo  Aerosol radiative forcing  Spectrometer (measure the surface albedo)  Measurement of the albedo on gray concrete.  Measurement of the albedo on black surfaces.  Measurement of the albedo on grass surfaces  Measurement of the albedo on water surface at different zenith angles.  Comparison of the surface albedo on different surfaces  Conclusion

3. value of one means that all incoming light is reflected  Surface albedo is the fraction of Sun’s radiation reflected from a surface.  Albedo is measured on a scale of 0 to 1  value of zero indicates the surface does not reflect, it absorbs all incoming light.  value of one means that all incoming light is reflected from the surface.  An ideal white body has an albedo of 1 and an ideal black body has albedo of 0

4. Earth receives both short and long wave radiation from the Sun Some radiation is reflected back to space – Albedo-global mean planetary reflectance Clouds, air molecules, particles, surface reflection Earth’s albedo  ~ 0.3 About 30% of the incoming solar flux is reflected back to space reflection of solar radiation are due to ice, snow, clouds, aerosols, and deserts surfaces.

8. Liou Xie et.al. 2002  This graph shows the land surface albedo over wavelengths 400- 1000nm.  From this graph we can see that the average albedo is approximately 0.3 or 30% and peaks around 900nm.

9. R. T. A. Prado, F. L. Ferreira/ Energy and Buildings 37 (2005) 295-300.  This graph shows the curve of reflection for red ceramics.  Values of reflectance were found to be around 9% in the UV range.  33% in the visible range  79% in the infrared(IV) range  The average albedo over all wavelengths between 290.0 and 2500.0nm was found to be 67.7%

10. Williams et al., 1993.

11. AEROSOL RADIATIVE FORCING Top of Atmosphere Idea Modified from Dr. Seth Olsen’s AGU Presentation 2006. Single scattering approximation S = Solar constant (1386 [W/m 2 ]) T = Atmospheric transmission (0.8) N = Cloudiness (0.5) g = Asymmetry parameter (0.7) w = Single scattering albedo (0.75) a = Surface albedo (MODIS)  = Aerosol optical depth Chylek and Wong, GRL, 1995 Strong Impacts on Boundary Layer Meteorology and Surface Radiative Forcing.

12. AEROSOL RADIATIVE FORCING James Hansen, NASA Climatologist

13. Red Tide spectrometer  Low cost  Small foot print (89.1mm x 63.3 mm)  The spectral response from 350nm to 1000nm wavelength  Utilizes a detector with 650 active pixel, that is 650 data point in one full spectrum.  Integration times as fast as 3 milliseconds Spectrometer help to measure :  Absorbance  Transmission  Reflectance

15. Solar Radiation  Visible light (42% of solar energy)  Near-infrared light (52%)  Ultraviolet light (5%) Albedo is the amount of sunlight that is reflected by a particular surface.

16. Black Asphalt Date: 28 th April, 2012 Time: 12:08 pm Black Paper Date: 1 st May, 2012 Time: 4:35 pm

17. Zenith Angle = 64.5544° Time: 16:35:00 Date: 05/01/2012 Albedo = 0.015 – 0.08 Zenith Angle = 27.0551° Time: 12:08:03 Date: 4/28/2012 Albedo = 0.08 – 0.22 Zenith Angle = 27.0551° Time: 12:08:03 Date: 4/28/2012 Albedo = 0.08 – 0.22 Zenith Angle = 64.5544° Time: 16:35:00 Date: 05/01/2012 Albedo = 0.015 – 0.08

18. Date : 28 th April, 2012 Time : 3:52 pm

19. (nm) Zenith Angle = 45.8890° Time: 15:52:15 Date: 4/28/2012 Albedo = 0.22 – 0.42

20. Date: 28 th April, 2012 Time: 11:50 am Date: 28 th April, 2012 Time: 12:00 pm

21. Green Grass Zenith Angle = 28.8215° Time: 11:50:02 Date: 4/28/2012 Albedo = 0.14 – 0.34 Green Grass Zenith Angle = 28.8215° Time: 11:50:02 Date: 4/28/2012 Albedo = 0.14 – 0.34 Dry grass Zenith Angle = 28.001° Time: 12:00:30 Date: 4/28/2012 Albedo = 0.18 – 0.47 Dry grass Zenith Angle =28.001° Time: 12:00:30 Date: 4/28/2012 Albedo = 0.18 – 0.47

22. Date: 29 th April, 2012 Time: 1:19 pm and Time : 5:10 pm

23. Zenith Angle = 31.0610° Time: 13:19:03 Date: 4/29/2012 Albedo = 0.1 – 0.27 Zenith Angle = 60.3233° Time: 17:10:20 Date: 4/29/2012 Albedo = 0.31 – 0.76 Zenith Angle = 60.3233° Time: 17:10:20 Date: 4/29/2012 Albedo = 0.31 – 0.76 Zenith Angle = 31.0610° Time: 13:19:03 Date: 4/29/2012 Albedo = 0.1 – 0.27

24. Gray Concrete Grass Surface Water Surface Black Road Wavelength(nm) Albedo Liou Xie et.al. 2002 Wavelength(nm) Albedo

25. Date: 5 th April, 2012 Time: 5:06 pm Date: 12 th April, 2012 Time: 4:30 pm

26. Clear day Zenith Angle = 67.5875° Time: 16:30:30 Date: 4/12/2012 Albedo = 0.16 – 0.30 Cloudy day Zenith Angle = 75.3181° Time: 17:06:10 Date: 4/05/2012 Albedo = 0.01 – 0.22 Clear day Zenith Angle = 67.5875° Time: 16:30:30 Date: 4/12/2012 Albedo = 0.16 – 0.30 Cloudy day Zenith Angle = 75.3181° Time: 17:06:10 Date: 4/05/2012 Albedo = 0.01 – 0.22 (nm)

27.  Measuring and monitoring surface albedo plays an important role in the earths energy balance and climate.  The Surfaces which have albedo 1 or close to 1, reflect almost all incoming solar radiation.  Most surfaces that have an albedo of 1 or near 1 are white in color.  The surfaces which have albedo zero or close to zero, absorb almost all incoming radiation.  Our measurements reveal that the albedo of black or dark surfaces was very low, ranging from around zero to approximately 0.2.  The albedo of grass varied from around 0.15 to 0.45 depending on the condition of the grass.  The albedo of water is dependent on the zenith angle and ranged from 0.1 to 0.76.  Concrete was found to have the highest average albedo out of the surfaces we measured, remaining at a fairly constant value of 0.3.  Our measurements are consistent with current known surface albedo values for various surfaces.