Sunset overlooking the Front Range from Longmont, CO in a stable atmosphere.
The purpose of this class is to visualize flow phenomena. For this image, we were tasked with taking pictures of clouds. Due to the many variables present in the physics of clouds, there were many distinct images submitted. For my submission, I photographed altostratus clouds at sunset.
Circumstances of Image
This image was taken in Longmont, CO at a friend’s house that overlooks the Front Range. I was facing west at the time and had the camera angled parallel with the horizon. It was taken on October 8th, 2016 at 6:32 pm. The weather was fair that day, with temperatures in the mid 60’s.
The sky to the east was fairly clear, indicating an orographic influence on the cloud formation. The atmosphere was stable, with a cape indication of 0, as can be seen in the Skew-T graph in Figure 1. Based on observation, I would guess the clouds are altostratus. The dew point was close to 11,000 meters and 5,800 meters. Altostratus clouds typically form between 2,000 and 7,000 meters .
Figure 1: Skew-T from the University of Wyoming.
Altostratus clouds usually form right before storms. In this case, there was no storm in the forecast. The clouds could have been formed due to warm air rising due to the mountains. This warm air is then cooled and condenses around the dew point level, which in this case is about 5,800 meters.
Figure 2 and Figure 3 show the image before and after post processing, respectively. I cropped the bottom to focus in on the clouds, while supplementing the image with them for context. Additionally, I adjusted the contrast and exposure to bring out the colors of the sunset. This in turn, darkened the mountains.
Figure 2: Original image.
Figure 3: Final, edited image.
The table below shows the camera specifications and settings for the image.
|Distance: Mnts to Lens||~4-5 miles|
|Focal Length||95 mm|
|Shutter Speed||1/400 sec|
I was very happy with the outcome of the image. Often sunset pictures feature pinks and reds, but mine is mostly blues and yellows. Also, I really like silhouette pictures, and was happy to finally try my hand at capturing this. I wish that the details of the clouds were more defined. I was hoping the contrast would bring them out, but it did not happen as much as I would have liked. Overall, I really like the image.