Earth Science Pic of the Day for Nov. 23

Lenticular Sky at Sunrise

November 23, 2011

Lenticular clouds in Argentina

Photographer: Hector Fabian Garrido
Summary Author: Hector Fabian Garrido; Jim Foster

The photo above showing a sensational display of lenticular clouds was snapped near La Rioja, Argentina, at the base of the Andes Mountains, on September 9, 2011. I was doing seismic testing just after sunrise and was taken aback by the gold and tawny wave clouds that appeared across much of the sky. These lenticulars took shape to the lee (east) of the Andes, just west of my location — the Sun was behind the camera. Lenticular clouds are generally orographic in origin, forming in lee waves when air is forced to rise over elevated terrain. On this early spring morning, the smooth structure of the waves, the illumination by the low Sun, and the absence of other types of clouds, gave the sky a surreal look.

Earth Science Pic of the Day for November 10th

Lake Loma Sunset

November 10, 2011


: Robert Farrimond
Summary Author: Robert Farrimond; Jim Foster

The photo above showing a magnificent early autumn sunset was taken at Lake Loma, near Marysville, Washington on September 24, 2010. When I first noticed this sunset I was in my front yard. As the impact of the colors started to sink in, I grabbed my camera and then loped over to the lake’s boat launch to snap this shot. It seems that often the camera doesn’t record what you’re actually seeing but fortunately, this wasn’t one of those times.

The formula for the most vibrant sunsets and sunrises does not include an expression for clear skies. When the sky is as clear as a bell as the Sun is setting, the western sky is in fact not very remarkable at all. To get the best colors, there must be something in the sky to scatter and reflect sunlight. On this evening, it was clouds at different heights. Even without clouds, certain aerosols and particulates (including smoke, soot and ash) may produce fine color too. The upper and most colorful cloud layer on this photo is composed of cirrus clouds. These are high enough to capture fiery color though at the surface the Sun had already set several minutes earlier. Clouds carrying less and less color are seen lower and lower in the sky. Accent these lower clouds with a few odd holes, add in some silhouetted conifers plus a rippled lake that reflects the sunset and conifers, then place some floating vegetation and reeds in the foreground, and voila – your masterpiece is complete.

Photo details: Canon T1i camera; 50mm EF lens; f/8.

Earth Science Pic for November 3rd

Balloon Flight Over Central Italy with Blue and Black Sky

November 03, 2011

Stratospera3-highest-small (2)

Image Created By: Francesco Bonomi; Francesco’s Web site
Summary Author: Paolo Amoroso; Jim Foster

The photo above was taken onboard a high-altitude balloon flight (StratoSpera 3 — the Italian StratoSpera Project) above Tuscany, Italy on September 10, 2011. The altitude is 129,892 ft (39,591 m). This photo is perhaps the highest ever captured from a non-scientific balloon. The view here is toward the south – the Tyrrhenian Sea is at top center and Lake Bolsena is at the upper left.

Note the blue color of the sky along the Earth’s limb and the black above it. This blue color is due to scattering of white sunlight – Rayleigh scattering. Scattering by very small particles (molecules of air) is greater at the violet end of the electromagnetic spectrum than at the yellow or red portions of the spectrum. Because our eyes aren’t as sensitive to the violet wavelengths as they are to blue colors, the sky takes on a bluish hue. At sufficiently high altitudes there are simply too few air molecules to effectively scatter sunlight and the sky is therefore mostly devoid of color. Passengers riding in the Concorde, altitude of 60,000 ft or (18,000 m), were able to observe a mostly black sky during daytime trans-Atlantic crossings.

Earth Science Pic for Thursday, October 20th

Fog and Redwoods

October 20, 2011

CanyonRidgePortrait (2)
Photographer: Hugh S. Stickney
Summary Author: Hugh S. Stickney; Jim Foster
The photo above showing sunny hillsides and valleys choked with fog was snapped in Sibley Volcanic Regional Preserve, California. This view looks down into the redwoods and bay laurels (Laurus nobilis) in the direction of the town of Canyon. Redwood Park is in the distance. Typically, the biggest and oldest redwood trees (Sequoia sempervirens) are found in deep valleys and ravines. Here, in addition to the cyclonic storms of fall and winter, fog drip and condensation is a regular occurrence. Trees above the fog layer, approximately 2,300 ft (700 m), are deprived of this source of moisture and are somewhat stunted in comparison. Photo taken on January 17, 2011

Earth Science Pic for Sept. 28th – Cloud Carpet Across the Alps

Cloud Carpet Across the Alps

September 28, 2011


Photographer: Hans van Hoogstraten; Hans’s Web page
Summary Author: Hans van Hoogstraten; Jim Foster


This stratocumulus cloud deck is blanketing the Jungfrau, the third highest mountain of the Bernese Alps, after Finsteraarhorn and Aletschhorn. The photo was snapped at approximately 11,500 ft (3,505 m) above sea level. At such altitudes, mountain slopes are still snow covered even in mid to late summer, as can be seen in the foreground. On this day, it seemed as though you could walk across the billowy carpet of clouds to the adjacent ranges. Photo taken on July 25, 2011.

Earth Science Photo of the Day for Sept. 27th

Cloud Fingers Over Tracy, California

September 27, 2011

Fingerclouds (3)
Photographer: Isolde Irene
Summary Author: Isolde Irene; Jim Foster
On the photo above, finger-like altocumulus clouds are seen stretching across an azure blue sky. These billow clouds (undulatus) formed in atmospheric waves. They’re oriented more or less perpendicular to the wind direction. Slots between the clouds appear where the wave dips (trough). The air temperature in the wave crest (where the wave climbs) is slightly cooler than in the trough, so atmospheric water vapor more readily condenses here. Cloud droplets evaporate; however, where the wave moves the cloud into the trough. Photo taken in the late afternoon of July 31, 2011, from Tracy, California.

Photo details: Olympus E-5 camera; f/11; 1/1000 sec. exposure; ISO 200; 14 mm focal length.