Total Solar Eclipse - 21/08/2017
My two weeks in the USA are coming to an end (at the time of writing), as we drive an RV across the barren desert of northern Nevada. A few days ago, what was undoubtedly the most documented total solar eclipse in history took place from the west to the east coast of the USA. Totality was almost exclusive to the US, with a partial eclipse visible across most of the Western Hemisphere. This blog post will give a brief overview of that epic day (from what I can remember).
 
Along with five friends, we planned a road trip across the western portion of the US - the first initial planning took place almost two years ago. The eclipse was the centrepiece of the entire trip, and the route was planned around this event. With five meteorologists on board, we had a distinct advantage over the many millions who watched the event - the initial plan was to head to Grand Teton National Park in Wyoming for totality. Checking the models 5 days in advance, we stuck to this plan, since they showed mostly clear skies, and there was still uncertainty in the forecast at this stage. 

However, the main NWP models eventually converged to show a very weak cold front associated with a small short-wave trough passing over the area during the event. This would bring a thin cirrus cloud shield during the eclipse. Ironically, in a situation the exact opposite to storm chasing, we were looking for an area that was completely cloud-free. Parts of central and western Idaho seemed like the ideal choice, since this was within a reasonable driving distance from Grand Teton (which we knew would be unbelievably busy). 

We initially chose a 11,000 ft high mountain close to the centre-line of totality, but upon driving through the area, we found the land to be owned by the US Government, with “No Trespassing” signs everywhere. We found out that they had been conducting nuclear research and testing all across the region, and there was a real threat of radiation poisoning. So, we eventually settled on the small community of Howe, about 10 miles south of the centre line. There was a steep hill around 300m high that overlooked the town, as well as the vast desert of central Idaho, to the east.  The view to the west was blocked by higher mountains, but we would have a great view of the Moon’s shadow racing away from us to the east.

​The view from the top of the hill (looking east).
Me on top of the hill (after the eclipse). The small town of Howe is directly behind me. Panorama is looking east. Credit: Hristo Chipilski. 

Setting off at around 9 am local time, it took us an hour to climb to the top of the hill (involving rock scrambling with heavy equipment), and we arrived about 20 minutes before the start of the partial eclipse phase. We remained at the top of the hill for over 3 hours and the entire duration of the eclipse (partial and total). With my home-made solar filter and a 300mm lens on my Nikon D3300, I took photos roughly every 5 minutes of the partial phases. Totality was 2m 14s, around 2s less than right at the centre of totality. Totality itself occurred at 11:31 MDT, and we enjoyed completely clear skies for the entire duration of the eclipse. The surface boundary layer was rather hazy, although the Sun was angled well above this. 

For the first 30 minutes or so of the partial phase, there was little discernible difference to the Sun from the naked eye. However, as partiality increased passed 50%, the sunlight became noticeably weaker and cooler, bathing the mountains in a strangely pale sunlight. This effect became more and more obvious towards totality (I eventually had to put a jumper on - the forecast high was around 30˚C). 

The events around and during totality are difficult to describe, not just because there was so much going on that I can’t remember it all, but also because I lack the vocabulary to fully portray the beauty of the event. In the final 10 seconds before totality, it became dark very quickly, and the moon’s shadow raced towards us quickly from the west. Totality itself was about the same brightness as a full moon, and I recall easily being able to spot Venus to the right of the Sun (I never noticed the other planets - there was too much going on). The street lights came on in the town below us, and we could hear cheers rising up from the crowds of people gathering there. Seconds after totality, my eyes shot to the ground to look for “shadow bands” - shimmering light patterns on flat surfaces that are the result of the last rays of light being retraced through both the Moon and Earth’s atmospheres. The distinct circular outline of the Moon's shadow could then be seen on the boundary layer haze, racing away from us to the east - an impressive sight. 

I watched both the beginning and end of totality - to see the famous “Diamond Ring” and Baily’s Beads, so I don't have any photos of this. During totality, I quickly took to solar filter off, and spent around a minute taking photos at various exposures - using a fixed aperture of f/10 and ISO 200, I took 11 photos at 300mm, with shutter speeds ranging from 1/4000s to 1.3s. I also took a single photo at 55mm with a 1.3s shutter speed (which didn't turn out very well). My video of totality using an iPhone 5s also completely failed, as the dynamic range was too great for the little sensor to cope with! All in all, I was very happy with my DSLR photos, and I also got to gaze at the eclipsed Sun for over a minute (and in-between photo exposures). Below is a fully compiled image of the eclipse (each photo is taken at 20-minute intervals). The Moon moved from top right to bottom left, relative to the Sun’s position. The image at totality was taken with a 1/50s shutter speed.

Compiled image of the phase of the eclipse. Moon moved from top right to bottom left, relative to the Sun.
Image of the eclipsed Sun with a 1/500s shutter speed. Prominences can be seen extending from the solar surface (red lines extending from the surface at approximately 12 o’clock and 2 o’clock).
Enhanced photo of the eclipsed Sun, taken with a 1/20s shutter speed. The Sun’s magnetic field lines extending from the surface can be clearly seen at approximately 10 and 4 o’clock.

​I simply remember gazing in awe and wonder at the beauty and brilliance of the eclipsed Sun during totality. There was so much visually going on during those brief 2 minutes, that I cannot begin to describe everything. However, now that the event has ended, a total solar eclipse is definitely something that I want to see again. Bring on totality in Texas on April 8 2024!
Best image of the eclispe - croped and edited. 1/160s, f/10.0, 300mm Nikon DX lens.