Tag: Glory

A Very Foggy Morning

Fog at sunrise in the Mormon Lake Basin.
Fog at sunrise in the Mormon Lake Basin.

A few days ago we had a cold front move across the area and overnight temperatures fell below freezing for a few hours in the higher terrain. It turns out that October is a good month for fog formation from these first frontal incursions. Area lakes still have relatively warm water from the recently ended summer. The passage of the cold air over the warm water allows for increased moisture flux from the warm water into the colder air that increases the dewpoint (and relative humidity) and can result in fog. Also, the shorter days–and longer nights–allows radiation fog to develop in the valleys.

Fog in the Mormon Lake basin with a colorful but diffuse glory.
Fog in the Mormon Lake basin with a colorful but diffuse glory.
A small sailboat lies at anchor on a foggy morning at Upper Lake Mary.
A small sailboat lies at anchor on a foggy morning at Upper Lake Mary.
Fog and Upper Lake Mary.
Fog and Upper Lake Mary.

With that in mind, I found myself driving past Lake Mary to Mormon Lake before sunrise on Tuesday morning. As I approached Lake Mary visibility dropped quickly to 1/4 mile, then 1/8 mile, and then 1/16 mile. Visibility improved once I passed both Lower and Upper Lake Mary. At Mormon Lake, there was fog swirling in the basin and the rising Sun was just starting to illuminate the summits of the San Francisco Peaks.

Fogbow over Upper Lake Mary.
Fogbow over Upper Lake Mary.
Fogbow over Upper Lake Mary.
Fogbow over Upper Lake Mary.

After the fog dissipated in Mormon Lake, I returned to Lake Mary where the fog was still present and I was able to capture fogbows plus a nice photo of a sailboat anchored in the lake.

Time-lapse video of the swirling fog in the Mormon Lake basin.

Time-lapse video of the swirling fog and glory in the Mormon Lake basin.

The time-lapse videos show remarkable motion of the swirling for over Mormon Lake as well as the colorful but diffuse glory that was present.

A very fun morning.

Fog definitions from Weather.gov:

(1) Steam fog (arctic sea smoke). Steam fog forms when water vapor is added to air that is much colder, then condenses into fog. It is commonly seen as wisps of vapor emanating from the surface of water. This fog is most common in middle latitudes near lakes and rivers during autumn and early winter, when waters are still warm and colder air masses prevail.

(2) Radiation fog (ground or valley fog). Radiational cooling produces this type of fog. Under stable nighttime conditions, long-wave radiation is emitted by the ground; this cools the ground, which causes a temperature inversion. In turn, moist air near the ground cools to its dew point. Depending upon ground moisture content, moisture may evaporate into the air, raising the dew point of this stable layer, accelerating radiation fog formation.

Fogbows, Glories, and Brocken Spectres

Another winter storm brought some snow but also morning fog to some of the low-lying areas. This type of shallow fog can produce fogbows as well as a Glory and Brocken spectre. I was not disappointed as all three were visible.

Fog bow with Glory and Brocken spectre.
Fog bow with Glory and Brocken spectre.
Glory and Brocken Spectre (center) with partial segments of a Fogbow.
Glory and Brocken Spectre (center) with partial segments of a Fogbow.

Time lapse (50x) of fog.

Another round of snow is expected this week.

Fog and Atmospheric Optics

Fog with a Glory, Brocken spectre, and two segments of a fogbow.

In the wake of a departing low pressure system I expected that there might be areas of dense fog in the morning. I awoke well before sunrise to look at satellite images to see if fog was developing. And, yes, there were some hints that fog was present. Good!

GOES-16 IR satellite image from ~5 a.m. showing large areas of fog across northern Arizona.
GOES-16 IR satellite image from ~5 a.m. showing large areas of fog across northern Arizona.

I left the house around 6 a.m. and headed east on Lake Mary Road. A few miles outside of town I ran into fog. Visibility dropped quickly to around 1/4 mile. Drive carefully!

My destination was the Mormon Lake Overlook. I had some success last winter at this site with a similar fog situation. As I approached the overlook the fog lifted becoming a low cloud deck above me. Hmmmm….not quite what I wanted. Ahead, I could see the edge of the cloud/fog. As I made the final approach to the overlook the road gained a bit of elevation and, suddenly, I was above the cloud/fog deck. Wonderful.

The sun had not yet risen but it was light enough to see that there was a shallow layer of fog covering the Mormon Lake basin. Moments later the sun began to rise through the dense fog.

Sunrise through the fog.
Sunrise through the fog.
Layers of fog at sunrise.
Layers of fog at sunrise.

With the sunrise a Glory and Brocken spectre became visible. Moments later, two short segments of a fog bow appeared. Also visible is a shadow of the overlook.

Fog with a Glory, Brocken spectre, and two segments of a fogbow.
Fog with a Glory, Brocken spectre, and two segments of a fogbow.
Fog begins to dissipate across the Mormon Lake basin.
Fog begins to dissipate across the Mormon Lake basin.

As the fog began to dissipate over Mormon Lake, I headed towards Anderson Mesa Station (home to several telescopes) because it is high enough to be above the fog. But first, along the way, the road dropped down into the fog and I saw this fog bow.

Fogbow near Lake Mary.
Fogbow near Lake Mary.

Finally, atop Anderson Mesa I once again was above the fog and able to photograph a Glory—this time projected onto trees with autumn colors.

Another glory and Brocken spectre projected onto fall foliage.
Another glory and Brocken spectre projected onto fall foliage.

Finally, here is a time-lapse of the fog over Mormon Lake that includes the Glory and the right-hand side of the fog bow.

Edit: Replaced GOES-16 visibile image with IR image.

Mormon Lake with Fog, Snow, Rime, and a Glory

A winter storm in late February brought hope again of getting some photographs of the San Francisco Peaks covered in snow. So I departed before sunrise one morning to head out towards Mormon Lake. Because of the warm winter up through mid-February, most of Lower Lake Mary and Upper Lake Mary remained mostly ice free. With very cold early morning temperatures it was no surprise that there was fog over the relatively warm open waters of the lakes. When I left my house, the temperature was about +3°F. When I reached Lower Lake Mary, the temperature had fallen to -10°F—and there was considerable fog.

A shallow layer of fog covers Mormon Lake.
A shallow layer of fog covers Mormon Lake.

It was the same over Upper Lake Mary. I debated whether to change my plans and shoot photographs of the fog over this lake but after viewing the scene I chose to continue to the Mormon Lake Overlook. As I approached the overlook, I could see a layer of fog. Luckily, the overlook was just high enough to be above the fog.

It was a beautiful scene with a shallow layer of fog covering the lake bed and snow on the distant San Francisco Peaks.

San Francisco Peaks as seen from the Mormon Lake Overlook.
San Francisco Peaks as seen from the Mormon Lake Overlook.

After getting a few quick photos I set about to capture a panorama. I shot 12 images: 2 rows of 6 shots. The resulting image is huge and clocks in around 190 megapixels. I can make a print of this that’s 8 feet wide. But I probably won’t because I don’t have a wall large enough for something that big.

It was obvious that sometime during the night the fog layer was much deeper as all the grasses, bushes, and trees were covered with rime ice.

Rime ice coats the grasses and bushes.
Rime ice coats the grasses and bushes.
Rime ice coats the grasses and bushes.
Rime ice coats the grasses and bushes.

The rime created needles that pointed in the direction of the light wind that had been present during formation. As the sun rose above the horizon, the rime caught the light and sparkled brilliantly.

A glory and a small segment of a fog bow are visible on the fog layer.
A glory and a small segment of a fog bow are visible on the fog layer.

So we had fog over the lake bed, snow on the mountain, and rime ice on the grasses. What else? Well, a glory became visible as the sun rose high enough to illuminate the fog layer below me. And a short segment of a fog bow was also visible in the fog layer.

Not a bad day for photography.