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The deposition mode ice nucleation efficiency of various dust aerosols was investigated at cirrus cloud temperatures between 196 K and 223 K using the aerosol chamber facility AIDA (Aerosol Interaction and Dynamics in the Atmosphere). Arizona test dust (ATD) as a reference material and two dust samples from the Takla Makan desert in 5 Asia (AD1) and Sahara(More)
The large (7 m×4 m cylinder, 84 m 3) AIDA (Aerosol Interactions and Dynamics in the Atmosphere) cloud chamber facility at Forschungszentrum, Karlsruhe, Germany was used to test the ice nucleating ability of two desert dust samples from the Sahara and Asia. Aerosol samples were lognormally distributed with a mode diameter of 0.4(±0.1) µm and geometric(More)
We present results of experiments at the aerosol interactions and dynamics in the atmosphere (AIDA) chamber facility looking at the freezing of water by three different types of mineral particles at temperatures between −12 • C and −33 • C. The three different dusts are Asia Dust-1 (AD1), Sahara Dust-2 (SD2) and Arizona test Dust (ATD). The dust samples(More)
We describe preliminary results from an optical scattering instrument designed to assess the shapes and sizes of microscopic atmospheric cloud particles, especially the smallest ice crystals, that can profoundly affect cloud processes and radiative properties. The new instrument captures high-resolution spatial light scattering patterns from individual(More)
The idea behind the marine cloud-brightening (MCB) geoengineering technique is that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre sea water particles might significantly enhance the cloud droplet number concentration, and thereby the cloud albedo and possibly longevity. This would produce a cooling, which(More)
We investigate the sensitivity of marine cloud brightening to the properties of the added salt particle distribution using a cloud parcel model, with an aim to address the question of, 'what is the most efficient particle size distribution that will produce a desired cooling effect?' We examine the effect that altering the aerosol particle size distribution(More)
Keywords: Asymmetry parameter Hollowness Ice crystal Ray Tracing RTDF Phase function a b s t r a c t Measurements are presented of the phase function, P 11 , and asymmetry parameter, g, of five ice clouds created in a laboratory cloud chamber. At À 7 1C, two clouds were created: one comprised entirely of solid columns, and one comprised entirely of hollow(More)
Proton-proton coupling can generate artifacts in sensitivity-enhanced HSQC spectra. These artifacts appear as cross-peaks involving remote protons. They are caused by relayed coherence transfer during the back-transfer portion of the pulse sequence. We present a product operator analysis of artifact formation and experimental results which demonstrate that(More)
The large (7 m×4 m cylinder) AIDA (Aerosol Interactions and Dynamics in the Atmosphere) cloud chamber facility at Forschungszentrum, Karlsruhe, Germany was used to test the ice nucleating ability of two desert dust samples from the Sahara and Asia. At temperatures warmer than −40 • C droplets were formed before ice crystals formed, 5 there was no deposition(More)
Keywords: Linear depolarisation ratio Cirrus Hollowness Ray tracing Back scattering Ice crystal a b s t r a c t Ice clouds were generated in the Manchester Ice Cloud Chamber (MICC), and the back-scattering linear depolarisation ratio, δ, was measured for a variety of habits. To create an assortment of particle morphologies, the humidity in the chamber was(More)