A digital holographic technique for studying mineral dust content in snow and ice cores

We propose a digital in-line holographic technique for accurate particle-by-particle characterization of airborne particles stored in meltwater samples from the cryosphere. Deriving information about particle shapes is critical to determine the intrinsic optical properties of dust, which are of great importance to increase the knowledge about aerosols and their contribution to radiative transfer through the atmosphere. To this end, digital holography has proven to be an excellent suite for distinguishing non-spherical particles, going beyond the common spherical approximation. It ensures a simultaneous measurement of particle cross-sectional area and extinction cross-section, which are important proxies in paleoclimate research and relevant to quantyifing the particle role in radiative forcing.