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Gary P. Ellrod and Andrew A. Bailey

1. Introduction Geostationary and polar-orbiting meteorological satellites have been used to help detect supercooled clouds that cause in-flight icing since the early 1990s ( Curry and Liu 1992 ; Ellrod 1996 ; Vivekanandan et al. 1996 ; Thompson et al. 1997 ; Smith et al. 2000 ). Satellite data have a number of distinct benefits in the analysis of aircraft icing such as multispectral capabilities, frequent sampling (geostationary satellites only), and excellent spatial coverage and

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Ben C. Bernstein and Christine Le Bot

1. Introduction In-flight icing can pose a significant hazard to aircraft and has been implicated as a contributing factor to many accidents. Drop sizes associated with icing cover a broad range and include supercooled large drops (SLD; including freezing drizzle and freezing rain), which are not covered by aircraft certification envelopes ( Federal Aviation Administration 1999 ). SLD has been shown to cause ice to form on unprotected surfaces, sometimes causing significant degradation in

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Jiazheng Lu, Li Li, Xunjian Xu, and Tao Feng

1. Introduction Overhead transmission line icing refers to the phenomenon of freezing rain, rime, wet snow, and mixed icing on overhead transmission lines ( National Meteorological Bureau of China 1979 ). Ice accumulation on transmission lines is one of the most serious threats to power grid safety ( Kiessling et al. 2003 ; Pytlak et al. 2010 ). Extremely heavy ice loads and transmission line galloping (high-amplitude, low-frequency resonant oscillations of transmission lines, induced by the

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Ronald M. Thorkildson, Kathleen F. Jones, and Maggie K. Emery

droplets rather than freezing rain or drizzle, and 2) that winds during the in-cloud icing event were from the west. When seen with the aid of binoculars, the ice on the conductors appeared to have the classic pennant shape, typical of ice accretion on the windward side of a nonrotating wire. The ice on the ground wires also formed on the windward side, but had an uncharacteristic broad, flat shape ( Fig. 1a ). Some sort of unusual motion of the ground wires may have led to the odd shape of the ice

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Zunya Wang, Song Yang, Zongjian Ke, and Xingwen Jiang

1. Introduction As important disastrous weather phenomena, icing events, especially extensive and persistent icing events, have great impacts on power industry and communication networks and have caused heavy socioeconomic losses. For example, unprecedented snow and icing hazards hit most of China, especially southern China, from 10 January to 2 February 2008. Over 100 million people were affected, with the direct economic loss exceeding 110 billion RMB ( L. Wang et al. 2008 ; Z. Wang et al

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E. Gregow, B. Bernstein, I. Wittmeyer, and J. Hirvonen

electricity network. It is important to recognize the large economic impact such decisions can make. For example, the buying and selling of electricity is highly dependent on the forecasts of the potential for wind energy that is expected in the coming hours and days. Beyond the direct and obvious effects of wind speed, the accretion and persistence of ice can have a large impact on turbine efficiency and thus the amount of electricity generated. In some cases, the effects of icing from supercooled clouds

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Ben C. Bernstein, Roy M. Rasmussen, Frank McDonough, and Cory Wolff

1. Introduction It is well known that in-flight icing caused by aircraft encounters with supercooled liquid water can pose a significant safety hazard. This is especially true for supercooled large-drop (SLD) icing, which has been identified as a contributing factor in numerous accidents [e.g., National Transportation Safety Board ( NTSB) 1996 , 2002 , 2006 , 2007 ; Green 2006 , 2015 ]. Over the last ~30 years, extensive flight, engineering and meteorological research has greatly improved

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Neil Davis, Andrea N. Hahmann, Niels-Erik Clausen, and Mark Žagar

locations. As of 2012, wind parks in cold climates account for approximately 4.1% of the 240 GW of global wind energy capacity ( Ronsten et al. 2012 ). For wind parks in cold climates, one of the largest sources of risk comes from atmospheric icing on the turbine blades. Atmospheric icing occurs on all structures that are exposed to moisture at temperatures below 0°C. There have been extensive studies of atmospheric icing both on cylinders, largely related to overhead power lines summarized in Farzaneh

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Stewart G. Cober and George A. Isaac

1. Introduction The Code of Federal Regulations Title 14 Chapter 1 Part 25 Appendix C (FAR 25-C) ( Federal Aviation Administration 1999 ) presents characterizations of aircraft icing environments for continuous maximum (stratiform) and intermittent maximum (convective) clouds. The icing environments are defined as functions of air temperature, maximum liquid water content (LWC), droplet mean effective drop diameter (MED), and horizontal extent. Note that MED and drop median volume diameter (MVD

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Cyril Morcrette, Katie Brown, Rebecca Bowyer, Philip Gill, and Dan Suri

handling of the aircraft, which can ultimately lead to a disastrous loss of control ( Cole and Sand 1991 ; Lankford 2000 , 2001 ; Politovich 2003 ). Meteorological factors, such as air temperature, humidity, and the presence and size of supercooled cloud particles, are important in determining the probability and severity of an in-flight icing event. In addition to some automated forecasts derived from numerical weather prediction (NWP) model output, operational meteorologists at the Met Office

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