What causes St. Elmos fire?

As a retired advanced weather spotter for the National Weather Service in Pontiac Michigan, I have observed numerous weather phenomon. I have “ball lightning” on video.

St. Elmo’s Fire is an electrical weather phenomenon in which visible plasma is created by a coronal discharge originating from a grounded object in an atmospheric electric field (such as those generated by thunderstorms).

St. Elmo’s fire is named after Erasmus of Formiae (also called St. Elmo), the patron saint of sailors (who sometimes held its appearance to be auspicious). Alternatively, Peter Gonzalez is said to be the St. Elmo after whom St. Elmo’s fire has its name.

Ball lightning is often erroneously identified as St. Elmo’s Fire. They are separate and distinct meteorological phenomena.(Wikipedia)

Physically, St. Elmo’s Fire is a bright blue or violet glow, appearing like fire in some circumstances, from tall, sharply pointed structures such as lightning rods, masts, spires and chimneys, and on aircraft wings. St. Elmo’s Fire can also appear on leaves, grass, and even at the tips of cattle horns. Often accompanying the glow is a distinct hissing or buzzing sound.

Benjamin Franklin correctly observed in 1749 that it is electric in nature.

Scientific Explanation

Although referred to as “fire”, St. Elmo’s Fire is in fact plasma. The electric field around the object in question causes ionization of the air molecules, producing a faint glow easily visible in low-light conditions. Approximately 1,000 – 30,000 volts per centimeter is required to induce St. Elmo’s Fire; however, this number is greatly dependant on the geometry of the object in question. Sharp points tend to require lower voltage levels to produce the same result because electric fields are more concentrated in areas of high curvature, thus discharges are more intense at the end of pointed object.

The nitrogen and oxygen in earth’s atmosphere causes St. Elmo’s Fire to fluoresce with blue or violet light; this is similar to the mechanism that causes neon lights to glow.

Flying through Iraq thunderstorm

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FMS Global News

Source

US soldiers in Iraq fighting drug-resistant bacteria after injuries

Contact: Amy Jenkins
amy@jenkinspr.com
312-836-0613
University of Chicago Press Journals

ALEXANDRIA, Va. — US soldiers in Iraq do not carry the bacteria responsible for difficult-to-treat wound infections found in military hospitals treating soldiers wounded in Iraq, according to an article to be published electronically on Wednesday, May 16, 2007, in Infection Control and Hospital Epidemiology. The article will appear in the June issue of the journal.

Investigator Matthew E. Griffith, MD, (Brooke Army Medical Center at Fort Sam Houston, San Antonio, Texas) and colleagues found that drug-resistant strains of Acinetobacter calcoaceticus-baumannii complex are not present on the skin of uninjured soldiers in Iraq, as had been expected.

A. calcoaceticus-baumannii complex is an important cause of trauma-associated and hospital-acquired infection throughout the world, and multidrug-resistant strains of the bacteria have been infecting injured soldiers treated in US military hospitals in Iraq.

“We need to know where these infections are coming from,” explains Dr. Griffith. “One of the possibilities was that A. calcoaceticus-baumannii was on the soldiers’ skin before injury and simply traveled to the wound site to cause the infection. However, our research shows that this is not the case.”

Although the consequences of the outbreak A. calcoaceticus-baumannii infection in US military hospitals serving soldiers wounded in Iraq are well described, the source of the outbreak is unknown.

To determine whether A. calcoaceticus-baumannii complex is carried on the skin of healthy US Army soldiers, investigators cultured skin swab specimens from 102 active military soldiers stationed at a base in Iraq. The base is in an environment representative of all Iraqi environments with desert, irrigated farmland and an urban area nearby.

Several previous reports have described skin carriage of Acinetobacter species in healthy people. The carriage rates have been found to vary with climate and geography. These reports may not be generalizable to US Army soldiers in Iraq, which has an extremely dry climate.

“If skin carriage is not the source of A. calcoaceticus-baumannii complex infection, then the other possibility is that the bacteria contaminates the wounds after injury,” explains Dr. Griffith. “This could happen while an injured soldier is awaiting treatment or in the hospital during or after receiving medical care.”

“This observation refutes the concept that the bacterium is acquired prior to injury among soldiers deployed to Iraq,” Dr. Griffith says. “In addition, this observation adds to the ever growing body of evidence implicating nosocomial transmission as the cause of the ongoing military outbreak.”

Because of this and similar research, an increased emphasis on infection control has been put in place in the US military’s combat hospitals.

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Infection Control and Hospital Epidemiology provides original, peer-reviewed scientific articles for anyone involved with an infection control or epidemiology program in a hospital or healthcare facility. Written by infection control practitioners and epidemiologists and guided by an editorial board composed of the nation’s leaders in the field, ICHE provides a critical forum for this vital information.

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