(YELLOWKNIFE, NORTHWEST TERRITORIES) Noctilucent clouds are a common target of northern astronomers during the bright summer months, but with wildfires and smoke dominating the news and skies these days, it seems there may be a new summer cloud on the rise: pyrocumulus clouds or “fire clouds.”
This 45-second time-lapse movie shows a unique side view of pyrocumulus cloud formation on July 4, 2015. This “fire cloud” event was triggered by gusty north winds that fanned a wildfire ENE of Yellowknife for over 12 hours. Convection peaked just before noon (about 15 seconds into the movie) when the surging heat of the fire generated enough upward thrust to form a cumulus cloud that was easily seen from the capital.
Pyrocumulus clouds are a signature of atmospheric turbulence commonly attributed to forest fires and volcanic eruptions – and indeed Saturday’s clouds were grand – however these clouds were nowhere near as ominous as the massive pyrocumulonibus clouds that towered above Fort Smith and Wood Buffalo National Park last fire season.
Photographer James Pugsley used a Canon 6D to capture one image every 20 seconds for over 12 hours. Boat traffic on Yellowknife Bay is shown in the foreground for context.
(YELLOWKNIFE, NORTHWEST TERRITORIES) A G4 (Severe) geomagnetic storm erupted this morning after a gust of solar wind known as a Coronal Mass Ejection slammed into Earth’s magnetic field approximately 15 hours earlier than expected, and with a lot more power than space weather forecasters had predicted.
The impact triggered one the most powerful geomagnetic storms of Solar Cycle 24, an event that peaked at G4 (Severe) near the top of the space weather scales for geomagnetic storms. Similar to hurricanes and tornadoes, geomagnetic storms are classified from G1-G5 by the National Oceanic and Atmospheric Administration.
While it is anticipated the G4 conditions will subside in the coming hours, it is very possible that storm activity will continue Tuesday evening and storm levels may return to G2 or higher overnight. Observers in Yukon, Northwest Territories and Nunavut should be on alert for colourful auroras in the East after sunset, and stay tuned to our Twitter feed as events unfold!