Lightning

[enorbet2]

I hope you don't mind two slightly connected stories at once. Many years ago I was living in a very small town in Western Colorado and in a nearby town's paper I read about four people who had just been released from the hospital having been struck by lightning on a relatively clear day while they laid on those aluminum and fabric lawn chairs and chaise lounges near a pool. The very next day I was to meet a candidate for a replacement 2nd guitar player for my band and it turned out to be the one who'd had his shoes blown off. We had to put off the audition for a few days until he got off crutches. He described how they could feel "the air go weird" just before it hit but in nowhere near enough time to react much beyond trying to get off the chairs. Everyone recovered in just a few days but were considered extremely lucky. I hired him.

 

A few months later, I was returning home, driving alone from a gig around 3:30 AM crossing section of high desert between Grand Junction and Delta and it was raining with increasing gusto and soon the lightning became so close and so bright that 1) I could not count any time between the strike and the thunder, and 2) It almost felt as if I could feel heat from the strikes that were really wide like hot ribbons (not "snaky") and coming so quick in succession, maybe one to three seconds apart that I had to slow down driving successively downshifting into first gear finally because my eyes couldn't recover between incredible blackness and searing white... I didn't want to outdrive my lights. I felt I had to keep driving though because once the hail reached over golf ball size I became very worried I was near a tornado due to the hail, lightning, and cacophony of wind that was trying to blow me off the road. It only lasted for about 4 miles, maybe a total of 20 minutes, but it was truly both exhilarating and frightening and obviously never to be forgotten.

 

BTW have any here seen the photos or shows of the various sprites above the clouds? Whoa! new phenomena!

[Turtle]

I hope you don't mind two slightly connected stories at once. ...

BTW have any here seen the photos or shows of the various sprites above the clouds? Whoa! new phenomena!

 

don't mind at all; thanks for posting. :rant::

 

we have a thread on sprites, though it's not much. >> http://hypography.com/forums/earth-science/7427-sprites.html

 

another short thread on jets. >> http://hypography.com/forums/physics-and-mathematics/12657-gigantic-jets.html

 

another thread on superlightning. >> http://hypography.com/forums/earth-science/3540-super-lightning.html

 

some links are repeated in them, but i think each thread has a little something different. :doh:

[Turtle]

Something new on lightning turned up at Spaceweather.com today. Here's a link and the abstract.

 

Evidence for solar wind modulation of lightning

Abstract

The response of lightning rates over Europe to arrival of high speed solar wind streams at Earth is investigated using a superposed epoch analysis. Fast solar wind stream arrival is determined from modulation of the solar wind V y component, measured by the Advanced Composition Explorer spacecraft. Lightning rate changes around these event times are determined from the very low frequency arrival time difference (ATD) system of the UK Met Office. Arrival of high speed streams at Earth is found to be preceded by a decrease in total solar irradiance and an increase in sunspot number and Mg II emissions. These are consistent with the high speed stream's source being co-located with an active region appearing on the Eastern solar limb and rotating at the 27 d period of the Sun. Arrival of the high speed stream at Earth also coincides with a small (~1%) but rapid decrease in galactic cosmic ray flux, a moderate (~6%) increase in lower energy solar energetic protons (SEPs), and a substantial, statistically significant increase in lightning rates. These changes persist for around 40 d in all three quantities. The lightning rate increase is corroborated by an increase in the total number of thunder days observed by UK Met stations, again persisting for around 40 d after the arrival of a high speed solar wind stream. This result appears to contradict earlier studies that found an anti-correlation between sunspot number and thunder days over solar cycle timescales. The increase in lightning rates and thunder days that we observe coincides with an increased flux of SEPs which, while not being detected at ground level, nevertheless penetrate the atmosphere to tropospheric altitudes. This effect could be further amplified by an increase in mean lightning stroke intensity that brings more strokes above the detection threshold of the ATD system. In order to remove any potential seasonal bias the analysis was repeated for daily solar wind triggers occurring during the summer months (June to August). Though this reduced the number of solar wind triggers to 32, the response in both lightning and thunder day data remained statistically significant. This modulation of lightning by regular and predictable solar wind events may be beneficial to medium range forecasting of hazardous weather.

Edited May 17, 2014 by Turtle

[LaurieAG]

Something new on lightning turned up at Spaceweather.com today. Here's a link and the abstract.

 

Evidence for solar wind modulation of lightning

 

Hi Turtle, the upper atmosphere changes described below are due to a similar solar mechanism. I found the pdf in the references for the wikipedia page below.

 

http://www.ips.gov.au/Category/Educational/Space%20Weather/Space%20Weather%20Effects/SatelliteOrbitalDecayCalculations.pdf

 

Summary: The decay of a satellite from low earth orbit is of interest to many people. The drag force that such a satellite experiences is due to its interaction with the few air molecules that are present at these altitudes. The density of the atmosphere at LEO heights is controlled by solar X-ray flux and particle recipitation from the magnetosphere and so varies with the current space weather conditions.

 

http://en.wikipedia.org/wiki/Orbital_decay

[Turtle]

Hi Turtle, the upper atmosphere changes described below are due to a similar solar mechanism. I found the pdf in the references for the wikipedia page below.

 

http://www.ips.gov.au/Category/Educational/Space%20Weather/Space%20Weather%20Effects/SatelliteOrbitalDecayCalculations.pdf

 

 

http://en.wikipedia.org/wiki/Orbital_decay

Hi Laurie,

 

That's an interesting observation and indeed the solar wind has a great many effects here on Earth. I introduced my article here only because it describes a new-found effect on lightning. :weather_storm:

[LaurieAG]

Hi Laurie,

 

That's an interesting observation and indeed the solar wind has a great many effects here on Earth. I introduced my article here only because it describes a new-found effect on lightning. :weather_storm:

 

It's a pity that all of the old links are gone because I recall that sprites have been recorded between the tops of the storm clouds and the upper atmosphere during lightning storms. It would be really interesting if sprites were included in future analysis to see if they also increase with lightning and upper atmosphere density during increased solar activity.

[Turtle]

It's a pity that all of the old links are gone because I recall that sprites have been recorded between the tops of the storm clouds and the upper atmosphere during lightning storms. It would be really interesting if sprites were included in future analysis to see if they also increase with lightning and upper atmosphere density during increased solar activity.

The links are bad but the threads remain. Here's the new links.

 

Gigantic Jets

http://www.scienceforums.com/topic/12325-gigantic-jets/?hl=sprites&do=findComment&comment=187622

 

Sprites

http://www.scienceforums.com/topic/7260-sprites/?hl=sprites

 

Super Lightning

http://www.scienceforums.com/topic/3441-super-lightning/?hl=sprites&do=findComment&comment=54340

 

Not sure if you saw the thread on the NASA HD camera experiment aboard the ISS, but it would be cool to spot some form of lightning live. (A meteor would do too. ;) )

>> http://eol.jsc.nasa.gov/HDEV/