Optical constants of ice from the ultraviolet to the microwave


Reference: Warren, S. G., and R. E. Brandt (2008), Optical constants of ice from the ultraviolet to the microwave: A revised compilation.
J. Geophys. Res., 113, D14220, doi:10.1029/2007JD009744. PDF link

This research was supported by the National Science Foundation under grants ANT-00-03826 and OPP-06-36993.

The 2008 compilation is a revision of the 1984 compilation:

Warren, S.G., 1984: Optical constants of ice from the ultraviolet to the microwave. Applied Optics, 23, 1206-1225. PDF link


Description of data set

This compilation of the optical constants of ice Ih is an update to the review by Warren (1984). Changes to the imaginary part mim of the complex index of refraction m are made in the following wavelength regions to incorporate more-accurate measurements made since 1984. References are given in Warren & Brandt (2008).

Wavelength
(microns)
Data source
0.161 - 0.181 Linear interpolation of log(mim) vs. wavelength between Warren 1984 and Minton (1971).
0.181 - 0.185 Minton (1971) revised for misinterpretation of original figure.
0.185 - 0.202 Linear extrapolation of log(mim) vs. wavelength of Minton.
0.202 -0.390 Extremely low value of mim in this wavelength range has not been quantified. See Warren et al (2006).
0.390 - 0.600 Warren et al. (2006).
1.40-1.43 Linear interpolation of log(mim) vs. wavelength between Warren 1984 and Gosse et al. (1995).
1.43 - 2.89 Gosse et al. (1995).
3.36 - 7.81 Gosse et al. (1995).
7.81 - 10.4 Cubic spline interpolation of mim vs. wavelength between Gosse et al. (1995) and Warren 1984.
26.0 - 75.0 Curtis et al (2005), temperature-adjusted to 266K. See Warren and Brandt (2008) for details.
75.0 - 300 Cubic spline interpolation of log(mim) vs. log(wavelength) between Curtis et al (2005) and Maetzler (2006).
300 - 2e+6 Maetzler (2006) at 266K .

The updated real part mre of the complex index of refraction m was computed using Kramers-Kronig analysis applied to the new mim, by the method described in Warren (1984). The real index differs substantially from the 1984 values in the far-infrared, 30-200 microns. Elsewhere it differs from the 1984 values by at most 2%.

Interpolation procedure for users:

For intermediate wavelengths not given in the table one should interpolate mre linearly in log(wavelength); log(mim) linearly in log(wavelength).


Download data set click on underlined link

ASCII data: 44 nm - 2 meter wavelength
column 1: wavelength (microns)
column 2: mre
column 3: mim

Printable Table to replace tables in Warren 1984
Format: pdf

Printable Plots comparing Warren 1984 with Warren and Brandt 2008
Format: pdf


Can black carbon in snow be detected by remote sensing?

Stephen G. Warren
Department of Atmospheric Sciences
University of Washington, Seattle WA 98195, USA

In review for Geophysical Research Letters
29 Oct 2012

Figure 1 Data Figure 1a Data Figure 1b

         

Figure 1

Figure 1.  Comparison of the spectral signature of snow thinness to that of black carbon (BC) in snow, for snow grain radius of 1 mm and solar zenith angle 60°.  (a) Spectral albedo of pure snow over a black surface for a variety of snow depths expressed in liquid equivalent.  The top curve is for semi-infinite depth.  Redrawn from Figure 13c of Wiscombe and Warren [1980], using updated optical constants of ice [Warren and Brandt, 2008].  (b) Spectral albedo of deep snow containing various mixing ratios of BC in parts per billion.  Redrawn from Figure 7b of Warren and Wiscombe [1980], using updated optical constants of ice and BC.  The optical constants and size distribution for BC used in the model are those described by Brandt et al. [2011].

 

 


Page maintained by Richard Brandt
brandt@atmos.washington.edu
Updated 30 Oct 2012