|
Experimental phase function and degree of linear polarization curves of millimeter-sized cosmic dust analogs We present laboratory measurements of the phase functions and degree of linear polarization(DLP) curves of a selection of millimeter-sized cosmic dust analog particles. The set includes particles with similar sizes but diverse internal structure(compact and porous) and absorbing properties. The measured phase functions are found to be in all cases very different from those of micron-sized particles. They show a monotonic decrease with increasing phase angle from the back- to the side-scattering region, reaching a minimum at large phase angles before a steep increase of the forward peak. |
|
Light scattering from volcanic-sand particles in deposited and aerosol form The light-scattering properties of volcanic sand collected in Iceland are studied here to characterize the sand particles and develop a reference for future remote-sensing observations. While such sand is common in Iceland, the smaller-size fraction can be readily transported by winds and found in the atmosphere at distant locations. The sand appears dark when deposited on a surface due to the high optical absorption of the material. Therefore, atmospheric regions containing such particles during a dust storm may absorb sunlight considerably, causing redistribution of solar energy. |
|
Experimental phase function and degree of linear polarization of cometary dust analogues We present experimental phase function and degree of linear polarization curves for seven samples of cometary dust analogues namely: ground pieces of Allende, DaG521, FRO95002, and FRO99040 meteorites, Mg-rich olivine and pyroxene, and a sample of organic tholins. The experimental curves have been obtained at the IAA Cosmic Dust Laboratory at a wavelength of 520 nm covering a phase angle range from 3◦ to 175◦. We also provide values of the backscattering enhancement for our cometary analogue samples. |