Sorry for the forum being offline some hours, guys! DM
Interesting photos ASLR, where were they taken - do you know?A4R
Hi Neven,I'd welcome your reporting it...Will you kindly give "honorable mention"? It is a major change and the details are on my blog.A4R
Neven: It is an unexpected honor to have something posted on the site.
Lightning was detected with a thunderstorm located over the Arctic Ocean north of Siberia between 00-02 UTC on 11 August 2019. A sequence of AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images from NOAA-15 (at 2315 UTC), NOAA-19 (at 0113 UTC) and NOAA-15 (at 0243 UTC)
Sprites or red sprites are large-scale electrical discharges that occur high above thunderstorm clouds, or cumulonimbus, giving rise to a quite varied range of visual shapes flickering in the night sky. They are usually triggered by the discharges of positive lightning between an underlying thundercloud and the ground.Sprites appear as luminous reddish-orange flashes. They often occur in clusters above the troposphere at an altitude range of 50–90 km (31–56 mi). Sporadic visual reports of sprites go back at least to 1886,[citation needed] but they were first photographed on July 6, 1989 by scientists from the University of Minnesota and have subsequently been captured in video recordings many thousands of times.Sprites are sometimes inaccurately called upper-atmospheric lightning. However, sprites are cold plasma phenomena that lack the hot channel temperatures of tropospheric lightning, so they are more akin to fluorescent tube discharges than to lightning discharges.
Lightning near the North Pole?Social media lit up this past weekend when a total of 48 lightning discharges were reported north of 85°N latitude, or within about 450 miles of the North Pole. The lightning came from low-topped, elevated thunderstorms that occasionally pop up over the Arctic, but seldom so close to 90°N. Elevated storms develop when moist, unstable air sits above cooler, more stable air near the surface. In this case, a surge of warm air swept toward the pole, riding atop much cooler air just above the mostly ice-covered central Arctic Ocean.
What’s most impressive about last weekend isn’t that lightning was detected so close to the North Pole, but that there was so much of it. Consider the admittedly short history of lightning detection over this northernmost part of the globe, as summarized for Category 6 by Vaisala researcher/engineer Ryan Said, developer of the GLD360 system. Since observations began in 2012, according to Said, only three prior lightning events were detected north of 85°N, and they produced a total of just nine flashes. By comparison, last weekend brought a total of 48 flashes to that region. All but seven of those were CGs, according to Said.In the larger area north of 80°N, a typical summer brings two to five events, with several dozen flashes in all. No single event on record had produced more than about 50 flashes until July 2018, when just over 300 flashes were observed on a single day. Last weekend, more than 1000 flashes were detected. About 80% of these were CGs, Said told Category 6.
WASHINGTON—Lightning strikes in the Arctic tripled from 2010 to 2020, a finding researchers attribute to rising temperatures due to human-caused climate change. The results suggest Arctic residents in northern Russia, Canada, Europe and Alaska need to prepare for the danger of more frequent lightning strikes, according to the researchers.A new study in Geophysical Research Letters, AGU’s journal publishing high-impact, short-format reports with immediate implications spanning all Earth and space sciences, used data from the World Wide Lightning Location Network (WWLLN) to map lightning strikes across the globe from 2010 to 2020 (interactive graphic). WWLLN sensors detect the short burst of radio waves emitted during a lightning strike.Lightning in the Arctic is historically rare, as it usually isn’t warm enough to generate the right thunderstorm conditions during which lightning occurs. But researchers have recently noticed more strikes occurring in the northernmost latitudes and they even reported several lightning strikes near the north pole in August 2019. Lightning strikes that do occur in the Arctic tend to happen in the summer when thunderstorms are most likely to form.The new study found the number of lightning strikes above 65 degrees north latitude during the summer months tripled from 2010 to 2020 as compared to the total number of lightning strikes over the entire globe during the same period.The Arctic is warming faster than any other region on Earth, and the study authors found the uptick in lightning strikes matched rising temperatures in the region over the past decade. Arctic temperatures increased by 0.3 degrees Celsius from 2010 to 2020; that warming has created more favorable conditions for intense summer thunderstorms that produce lightning, according to the authors.
