Citation: Lab study indicates feldspar dominates ice nucleation in clouds with mix of water and ice (2013, June 13) retrieved 18 August 2019 from https://phys.org/news/2013-06-lab-feldspar-dominates-ice-nucleation.html Explore further Feldspars are a group of minerals that are believed to make up as much as 60 percent of the Earth’s crust. The name comes from the German words “field” and Spath (rocks that don’t have any ore in them.) Prior research has shown that they make up on average just 3 percent of the dust found in clouds, which has led scientists to conclude that they play a minor role in ice formation. In this new effort, the researchers found just the opposite to be true.The amount of ice that forms in clouds is important because it determines how large clouds grow, how long they last and their radiative properties. Because they make up so much of the mass of dust (about two thirds) in clouds, scientists have believed that clay minerals were responsible for most ice nucleation—where water adheres to dust particles kicking off the formation of ice crystals. Now it appears that feldspars play an inordinately important role.To find out what really goes on inside of clouds, the researchers used special cooling chambers in their lab along with various mixtures of dust created to simulate that found in the natural atmosphere. Water vapor in the chamber formed droplets on slides allowing the researchers to study the ice crystals that grew on the minerals that were in them. By watching the process as it happened, the researchers were able to see that most ice nucleation occurred on feldspars rather than clay mineral material.The findings by the team suggest that human activities may be having a larger impact on cloud formation and their properties than has been previously thought—the amount of feldspars in the atmosphere has been rising consistently over the past several decades due to landscape changes in arid areas. Prior research has shown that dust that winds up in clouds comes predominately from arid regions such as the Sahara desert. An increase in feldspars in the atmosphere, the researchers conclude, may be having a still unknown impact on global climate. (Phys.org) —A team of researchers at Britain’s Institute for Climate and Atmospheric Science, University of Leeds, with assistance from Australian Matthew Woodhouse of Commonwealth Scientific and Industrial Research Organization has found that feldspar minerals play a far larger role in ice formation in clouds than has been realized. In their paper published in the journal Nature, the team describes their lab studies that revealed the important nature of feldspar in ice nucleation in clouds. Cloud in Nepali sky. Credit: Wikipedia More information: The importance of feldspar for ice nucleation by mineral dust in mixed-phase clouds, Nature (2013) doi:10.1038/nature12278AbstractThe amount of ice present in mixed-phase clouds, which contain both supercooled liquid water droplets and ice particles, affects cloud extent, lifetime, particle size and radiative properties1, 2. The freezing of cloud droplets can be catalysed by the presence of aerosol particles known as ice nuclei2. One of the most important ice nuclei is thought to be mineral dust aerosol from arid regions2, 3. It is generally assumed that clay minerals, which contribute approximately two-thirds of the dust mass, dominate ice nucleation by mineral dust, and many experimental studies have therefore focused on these materials1, 2, 4, 5, 6. Here we use an established droplet-freezing technique4, 7 to show that feldspar minerals dominate ice nucleation by mineral dusts under mixed-phase cloud conditions, despite feldspar being a minor component of dust emitted from arid regions. We also find that clay minerals are relatively unimportant ice nuclei. Our results from a global aerosol model study suggest that feldspar ice nuclei are globally distributed and that feldspar particles may account for a large proportion of the ice nuclei in Earth’s atmosphere that contribute to freezing at temperatures below about −15 °C. Dust dries clouds by gobbling up water vapor: Scientists show how different cloud seeds can influence greenhouse effect © 2013 Phys.org Journal information: Nature This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
The NCC Republic Day (RD) Camp 2017 began at the NCC Camp, Cariappa Parade Ground, Delhi Cantt on January 1 this year. Lt Gen Vinod Vashisht, VSM and Bar, Director General National Cadet Corps addressed the cadets and officials on the occasion and called upon all to derive a deep sense of purpose from each activity in the camp which is unique with no parallel.2068 Cadets including 696 girl cadets drawn from 17 NCC Directorates, covering all the States and Union Territories of the country are participating in this Camp. Also Read – Add new books to your shelfThis also includes 102 cadets from J&K and 162 cadets from North Eastern Region (NER). The cadets are selected through a tough selection process. The cadets attending the camp follow an intense schedule over one month while participating in a number of activities like cultural, national integration awareness programme and institutional training competitions. The camp will be visited by a large number of civilian dignitaries including the Vice President of India, Raksha Mantri, Raksha Rajya Mantri and the Chiefs of the Army, Navy and Air Force. Also Read – Over 2 hours screen time daily will make your kids impulsiveThe aim of the Republic Day Camp is to enhance the self confidence of cadets, deepen their value systems and provide an exposure to the rich culture and traditions of our nation and the important events that take place in the national Capital during the run up for Republic Day. Projection of cherished ideals and capabilities of the cadets of the NCC is intrinsic. The camp portrays a reflection of ‘Mini India’.While speaking to the media, the Director General highlighted the major achievements of the NCC in Youth and Nation Building, Social Awareness Campaigns, Community Development, Environment Protection, Sports and Adventure.The conduct of NCC National Games in Oct 2016 has added another feather in the cap of this premier youth organization of the nation.Lt Gen Vashisht also mentioned that the Training Philosophy of the Cadets had been refined to accommodate the changing aspirations of our youth and expectations of the society.