Pacific cloudscape, SF->Hnl. 2005. Can you see the curvature of the Earth? I almost thought I could.
Complex cloud system east of Honolulu dropping rain in the center right and with a rainbow added on the top.
Orographic cloud trails from Maui and Big Island, viewed from near Blowhole, Oahu. Maui is visible easily. I half think I see Big Island to its right. Supposedly, this kind of cloud can help lost sailors find an island they cannot see.
Cap cloud over Ko'olau mtns, from Manoa
Lenticular cloud from the Saddle Rd between Maunas Kea and Loa. It lasted at least 15 minutes but we lost sight of it as we drove along. The blueness is courtesy of Costco's lacklustre photo development service (yes, this is from my old film camera).
Lenticular clouds near Kitt Peak, Az, viewed under the arm of the McMath Solar Tower. The clouds held in position for at least 30 minutes, but changed in form on timescales of a few (5?) minutes. In the distance I could see many similar, but smaller, clouds. A bit like giant white UFOs lurking behind the telescope.
This lenticular spent half an hour at sunset trying to grow in the wind-shadow of a ridge by my house.
Wave cloud, probably from ripples on the interface between two airmasses. From the winds and cloud speeds I am guessing that this cloud was about 0.5 to 1 km up and the wavelength was maybe 100 or 200 m, but I don't really know. Shefford, UK. The ripples lasted about half an hour before smearing out.
Rayleigh-Taylor instability traced by cirrus clouds. This was in the morning, a couple of hours after sunrise, in deepest, darkest Wales. The clouds mark slightly cooler, denser air that is falling into warmer, less dense air, so making the instability. The streaks above the mushroom caps show the net motion of the cirrus, downwards in this picture. This picture is further explained in this paper: http://rsta.royalsocietypublishing.org/content/368/1916/1663
Low morning clouds, Manoa Valley. These ones are probably 150m up, adjacent to the west wall. They just met the rising sun and are starting to evaporate. Half an hour later they were gone.
A very wet morning, in the "40 days of rain".
A very low (100m?) stratus cloud base.
Volcanic fog ("vog") layer to the east of Mauna Kea, beneath cirrus clouds and above the thermal inversion-capped convective clouds. The vog is not so white as the water clouds because of sulphur in the droplets. The inversion at the time of this picture was at 6000ft. The photo was taken from 14000ft.
Low ocean clouds and their shadows. South of Maui from 25000ft.
Three bands: next to the coast brown = nearly lifeless rock; then yellow = parched grass; green = living grass. The clouds tell the story: the land is higher to the left in this image, forced cloud formation there gives rain and shadow protection for plants. The coast is a desert, too hot and dry for much to grow. In between, plants grow when they can but are summarily cooked to yellow when the rain fails to materialize. This is the Waikoloa area on the NE side of Big Island, looking south to Hualalei (whose black flows are visible near the top).
Sunset from Manoa
Clouds lit from underneath by the setting sun.
Oil film on a wet, grooved concrete road surface. Grooves about 1cm wavelength. Field width about 2 feet.
Night rain. I placed the camera near ground level and shot horizontally. The light is backscattered from the camera flash. Exposure is 1/80th second. The region where the drops are in focus is about 0.5m across. Nearly vertical lines are falling rain. These drops are brighter at the top end, presumably because the flash intensity fades through the duration of the exposure (but maybe there is another reason?). You can use this to see which way the drops were going: the brightest part marks the start of each trail. Shorter arcs, many of them near horizontal, are droplets splashed up from the ground. Note the helical tracks. I think these are either spinning droplets with elongated shapes or drops whose shapes are unstably oscillating just after their formation by impact. The more obvious helixes have 3 or 4 turns, corresponding to 240 - 320 turns per second (half that if doubly periodic). Water surface tension is ~0.1 J/m2, giving maximum spin rate 400/s for droplet radius 0.5mm. So, consistent.
Milk foam. This is back-illuminated through about 5cm of foam. The yellowy color is from the milk itself. Cell size is roughly 1 mm. Here are the cell side counts: (Nsides:Ncounts) = 3:0, 4:2, 5:15, 6:17, 7:5, 8:3, 9:1, 10:1, 11:0. (e.g. 5:15 means I counted 15 pentagons). I counted shapes in two strips, at the top and bottom, to make it easier. There's some evidence for a spatial variation in cell size - e.g. the large N cells tend to be at the top. Most surprising is that there are not more hexagons. And there are no triangles. Why not? Also, if you plot Ncounts as a function of Nsides, the distribution is like a Maxwellian. Why? This has to be a minimum energy configuration but my first guess would be that minimum energy would associate with a particular shape (hexagon) and you should see a lot of side-by-side hexagons. Evidently not.
Another milk foam picture, this time in B/W and contrast enhanced.
Caustics in a swimming pool. Note the colors on the ring. Field width about 2m.
Manoa Falls with, to its left, a new channel caused by a rockslide during a very wet 2006. Erosion in action. A quick calculation suggests that this is not a dominant mode of erosion in the valley - i.e. Manoa Valley was not primarily excavated by rockslides like this one.
Here's the "before" picture. A little misaligned and with a different camera, but the rockslide track is clearly not there.
Wave action in beach sand, Santa Barbara.
Picture of the Moon taken by holding a Canon XTi to the eyepiece of an 8" Celestron. Note the blue tinge on Mare Tranquilitatis (11 o'clock from the middle of the picture).
Same image but stretched to emphasize color differences. The blue tinge on Mare Tranquilitatis is clear. The edges of Serenitatis are also blue. These color differences result from compositional differences, principally the TiO2 content, in the basalts that fill the giant basins. Bluer means higher Ti content.
Lava cross-section, Manoa Valley. The layers are roughly 1 meter thick, alternating ash (reddish) and basalt (grey).
Basalt dyke. This is the side of a road cut at the Pali Lookout, Oahu. The layering of the rock at the left and right is horizontal. A vertical crack in the middle has been opened by intruded rock, which shows a *vertically* banded structure of slightly lighter rock (I guess because the dyke was intruded into cold rock and cooled by conduction horizontally). The feature is 2-m wide at the top. Small holes at the bottom are unused dynamite holes from the road cutters.
Enhanced, magnified view of the vertically banded structure from the previous picture. Some of the vertical joints are being used by plants, at the top of the picture. The lighter region is about 2m wide at the top.
Stalagmite (left) and stalagtite (right) growing side-by-side. In fact, the stalactite grows into the base of the stalagmite. How did this happen? Both are about 8 meters tall. Luray Caverns, Virginia.
Same two structures closer up. Quite intricate.
Extremely fine layers (just 2 or 3 mm thick) of volcanic ash exposed near the Makapuu Lighthouse trail. The layers are cemented so weakly that they can be broken off with the slightest touch, and pulverized to sand between the fingers. Sticks at the bottom are roots that have driven right through.
The very fine, layered ash has eroded from this cut making the sand pile at the bottom. Above is a layer with plant matter mixed in ("soil"). Vertical and horizontal light bands appear to be channels taken by roots of plants from above. I don't know why they are light, though. It looks like the wooden roots have been replaced with some agglomerated mineral almost as crumbly as the ash deposits around them.
Part of a rusty corrugated iron water pipe, discarded on the beach. Absolutely beautiful.
Close-up of the same pipe.
Close-up of the footpath leading to the sea, near Makapuu Lighthouse. The system of cracks is due to the sun heating and drying-out wet ground (the day before the picture was taken was rainy). Numerous plant parts are scattered across the picture. Also visible are coral (shaped like a person's head), glass, vesicular lava and other small stones. Width of frame about 4 inches.
Close-up of a footpath composed of weakly cemented, heavily degraded, sun-baked, iron-rich volcanic ash. Field width is about 30 cm. The trumpet-shaped objects are flower supports from some nearby bush. This is on Kuliouou trail about 1500 ft up.
Drying cracks in concrete. Keck HQ, Waimea. Even more excellent when zoomed.
Drying cracks in concrete, closer view. Keck HQ, Waimea.
Sand near Makapuu beach, Oahu. The black grains are volcanic, the white ones are mostly shell-parts and perhaps some coral.
Sand from the turtle beach, near Haleiwa. Many fewer dark volcanics than in the previous sample.
Pollution trail from a barge being pulled out of Pearl Harbor. I don't know what's in the barge. Looks like it could be sewage, mud, or even oily sludge from some Navy clean-up. The channel is deep enough to accept aircraft carriers, so I don't think the barge is dredging up bottom sludge (and the bottom is bright coral sand in any case). The picture is here because it shows the shape of the wake nicely, and look how the sludge is diced-up perpendicular to the motion. Why?
Drainage system on the flatlands east of Denver, Colorado, highlighted by a light snowfall.
Waterspout south east of Honolulu (about 5 minutes before landing). Unlike the rain sheets all around it, the spout is narrower at the bottom than at the top and there is disturbed water (fall-back) at the bottom. My eye showed it better. Try the zoom tool (upper right magnifying glass).
Approximately 1.5cm of rime on an angle-iron at the UH telescope, Mauna Kea, complete with perfect holes where the air blew through, each with nicely rounded edges.
Ice sculpture made in rime at 14000 ft. This ice formed over about a week of cold, wet summit conditions, with wind consistent from the north east (right to left in this picture). The rime grows on the right sides of objects hit by the airflow. Although the air temperature remained <0 during this period, the rime is slowly ablated in the wind (which was rapid, about 35 mph at the time of this photo). Places where the ice was thin have opened into holes, and the weight of the ice is pulling some of the material downwards.
Rime build-up on a car wing mirror, Kitt Peak AZ summit.
An enormous convection cell dumping rain on Manoa Valley. As I watched for 2.5 hrs from a nearby boat, 5 or 6 such clouds appeared and then vanished, each dropping huge amounts of water. They form over the Koolau mountains on the far side as wet air is pushed upwards, cools, releases latent heat from forming droplets, and goes unstable.
Vortex on the wing of a 777 at about 10,000ft while descending into Honolulu.
Contrail and its shadow in the cold sky above Shefford.
Low clouds seen against a background of LA city lights.
Lunar eclipse at moonrise, Sandy Beach, Oahu.
Koko at sunset, from the east.
Convection cells in a bottom-heated open pan containing miso soup, at Ichiriki. Field diameter about 15 cm. This is just after heating started and before the convection became vigorous to turbulent.
The triple blowhole at the base of the Makapuu Lighthouse trail, Oahu. The three vents are fed by a single tube to the ocean and work in tandem. They spit droplets, vapor or just air depending on the phases of the waves, and emit a terrible booming sound. Highest jets I saw in a 2.5 hour stay were about 20 ft tall.
Hanauma Bay crater erupted recently (50kyr) on the Eastern tip of Oahu through pre-existing basalts and coral formations. Bits of basalt and coral embedded in tephra are on display along the eroded inside wall of the Bay, most sub-centimeter some up to fist size and a few as big as your head. This surface is exposed by collapsing after wave-cutting at the bottom.
Close up of embedded basalt and coral from the pre-existing terrain at Hanauma Bay. Field here is about 6 inches across. Where the stones have fallen out there is a yellow glassy substance.
In a tide pool on the North Shore, small rafts of self-sticking sand float on the water and cast bright-rimmed shadows on the sandy bottom 10cm below. The bending caused by the surface tension edge of the sand rafts is obvious here as it images the sand bed into a sunspot-like penumbra around each raft. The same curved water surface creates the bright shadow rims, many of which appear chromatic.
Fog cap descending a mountain ridge between San Fran and Santa Barbara and evaporating as it warms adiabatically. It's not at all thick - note the radio mast sticking through the cap.
Heavy hydrocarbons oozing out of an upturned rock on the beach at Santa Barbara.
Even though baked in the full sun for a long time the oily ooze remains soft to the touch and sticky, for feathers and fingers alike. Some blobs, like this one, appear to have floated in on the ocean.
A big blob of heavy hydrocarbon ooze into which many small rocks have stuck, probably as this thing rolled around on the beach. The oily material has subsequently oozed out the bottom.
Clouds over Maui caused by the adiabatic cooling of air rising to pass the island. From a Continental 767 approaching Honolulu.
Cloud streets over southern Texas.
Sediment in meandering river, southern Texas. This may be the Rio Grande.
Meander, oxbows and other failed stream paths. Southern Texas.
Convective anvils with stratus in the upper foreground. Over Texas.
Black mountains from an ancient continent-collision eroding into debris aprons and desert dunes beyond.
Channel eroded through loose sediment by an ice-fed river running across the Gobi desert, near the end of the Great Wall at Jiuquan. The cut is about 50-m tall and widens towards the bottom. Why? Maybe erosion by sideways "splatter" droplets that becomes more important as the drop distance increases? Also, the front face shows that rock drops off from the top down (the lower parts stick out relative to the upper). That is strange because I would have thought that the dominant erosion is from the river, which would tend to undercut the banks and cause the bottom bits to fall out first, followed by collapse up to the top later.
Thermal inversion seen above a steel-making factory near Jiuquan, Gansu. This picture, taken in the morning (at about 8 or 9 am) shows how stable is the air on the plains between the mountains. Presumably, cold air rolls down from the mountains at night and pools on the valley floor, creating the inversion. Maybe this would be a good place for a high-resolution imaging telescope.
A nice mushroom cloud over the inner Mongolian part of the Gobi desert.
Row of collapsing convection cells viewed in projection against the sunset sky, Manoa.
Water droplets condensed on a glass window at the top of a kettle. Field width about 10 cm.
Mirage on the Saddle Road, Big Island. A dip in the road about 300 yards ahead gives grazing angles suitable for total reflection. Things to see: 1) The indistinct nature of the images above the total reflection line, caused by extreme road turbulence (the camera *is* focused) 2) the convergent reflections of the edge white strips 3) reflection of the distant yellow center markers as a stubby vertical line to the right of the actual yellow markers in the foreground 4) reflection of the distant orange traffic cone. The latter gives an idea of the angles...the cone is about 2 ft tall and it was about 200 yards beyond the mirage: 2/600 = 1/300 or about 0.2 degrees. I crouched in the road with the camera at a similar height to take this picture. Question: why does the mirage have shiny upper and lower edges, but a matte interior?
Solidified bubbles in a pancake.
Rust on a child's slide. About 10cm across.
Reflections in a swimming pool on a windy night (no people in the pool). The source is a sodium light, to the left. On the right, individual specular reflections of the light make little loops as the waves move by. Some loops show the 50 Hz electricity frequency. Black spaces are the wave bottoms reflecting only dark sky. On the left the reflections merge (greater distance), the wave bottoms are invisible because of the grazing view angle and there are no angles that can reflect the sky. Redder color is from the illuminated wall behind the light. [Try zoom tool].
FeS crystals in a sample from Cornwall, UK. The biggest ones are a little more than a millimeter across. [zoom tool = good]
Small cloud in a vortex over the wing of a 777 approaching Honolulu on a humid evening.
Wrap-over cloud formed when a cap of moist air is suddenly pushed upwards (and cooled) by the force of an ascending cumulus cell. It differs from the cloud beneath it by not being convective. This one (the diffuse band at the top of the main fluffy cloud) lasted about 2 minutes.
Glass from a smashed window on a car. Looks great under the zoom tool, as well.
Diffraction through an aperture. Plane waves enter, circular ones leave. Picture looking down from Diamond Head: simple, but effective.
Simultaneous eruption clouds from Halemaumau (right) and the ocean lava entry point (left). Viewed before sunrise from the Mauna Kea access road after a night of observing on Sept 28 2008.
Awesome sheared anvil cloud spotted at sea-level sunset. Like an atomic bomb cloud, this one rises and is sheared left (south-ish) by the prevailing high altitude winds. Vigorous convection cells in the rising air cause the lumpy ''mammiform'' underside of the upper left. The grey clouds are dark because they are out of the Sun - they moved quickly to cover the cloud from left to right, interrupting the timelapse movie I took of the anvil ascending. The lower parts of the anvil are reddish because they are illuminated only by the red rays of the near-horizon Sun.
Turbulent convection in the air above a hot grill at a restaurant. The point-like camera flash casts distinct "shadows" and freezes the motion, whereas to the eye these cells are barely visible as a low contrast shimmer. The hot plate is (I'm guessing) 200K hotter than room temperature.
Shell sand. Nearly every grain in this sand is a smashed, wave-polished shell or a tiny piece of coral. Only the black grains are rounded volcanic grains. Note the green spiral to the right of center and the pink banded shell at 1 o'clock. Average grain size about 1mm, at a guess. From a beach west of Shark's Cove, Oahu. Try the zoom tool. [too bad about the focus gradient - this was an extreme macro shot with a lens not really good enough].
Ice crystals growing on the window of a 767 at 34,000 ft.
The natural color of ice: blue. This is the top view of a 300lb columnar block of ice. Tiny bubbles and fractures cause the white coloration in the rectangular core and round the edges. The blue regions are where the ice is transparent and long path lengths are possible. These columns are roughly a meter tall, so the absorption length for red light must be something like a few meters up to maybe 10 meters (because the color is not really strongly blue). If the absorption length is 1/[opacity*density], this means the opacity is about a few * 10^(-4) m^2/kg at, say, 6500Å. I'll check that out on google. In this picture the light is mostly sunlight streaming through an open door to the right, passing through several blocks, then entering the columnar transparent zones. In the freezer at the Union Ice Company, Van Nuys, CA.
Stalagmites forming inside the refrigerated warehouse of the Union Ice Company, Van Nuys, CA. About 10cm tall. I told myself they were brown because they formed from drips from a rusty pipe.
Pattern of cracks in the window of an Embraer aircraft taking us from LA to Boise, seen projected against the blue sky. Picture width is about 15cm. My guess from the curvature is that they are stress cracks, but I don't know why they have those snake-like bends in them. I thought they were filled with ice but they remained nearly as visible upon landing, so probably not. Nice when zoomed.
The painted surface of the boot of a car, stained and eroded by exposure to the elements, including exposure to falling ash from a forest fire (the black bits). Region shown is about 60cm across.
Sand ripples at the edge of a lake in Potsdam, Germany.
Row of vortices shed by a fish swimming (from 5 o'clock to 11 o'clock in this picture). Although they're individually spun off by the flap of the fish tail, they otherwise resemble a von Karman vortex street formed by alternating eddies shed from an obstacle in a viscous flow. Scale here is maybe 3m left to right and 8m top to bottom (foreshortened picture from bridge over a lake). I waited forever to get a better vortex sheet - this remained the best I saw.
Morning fog in a gently-sloped river valley, Buellton, CA.
Fog bank crossing US101 in Buellton, CA.
Cracked ice puddle on a grass hillside.
Wind-blown snow field on ploughed ground. Wavelength about a foot.
20 cm patch of snow. Black bits are debris from pine trees nearby. The surface has been partially melted and refrozen with the day-night cycle, so the grain size is quite large and most of the pine bits are embedded. [zoom]
High brightness cut of the same image, show distribution of glints.
Glass fracture pattern, amazingly symmetric, made when my head hit a stressed glass window at NRAO. The pattern extended vertically about 3 to 4 feet from the point of impact, yet has tiny symmetric structures (like the central butterfly wings) only a few millimeters across. This was a triple layer safety window about 8 ft tall - only the middle window fractured. The outer panels held the cracked fragments in-place, luckily for me.
Magnificent convective column show several classic features. At the bottom is the flat base where ascending water condenses out. Visually, but less obvious in this picture, the flat base was not horizontal, maybe caused by a wedge effect between two airmasses (I'm guessing). The column corkscrews as it rises, completing about 1.5 or 2 turns in total. This is initial angular momentum picked up from shearing winds and amplified. At the top, the column overshoots into warmer air and is no longer bouyant, falling out into a flattened, asymmetric disk-like structure. Behind the column, rain or ice grains fall out in opaque sheets.
My plane was at 30,000ft over Kansas (headed west) and we took 10 minutes to pass this thing to our south at 500 mph. From this, I judge that it was about 15 km tall (> scale height!), 4 km wide at the base and roughly 75 km away. The overshoot disk was about 80 km in diameter and perhaps 1km thick, full of organized, seemingly spiral structure.
The column from slightly further west.
This is roughly a Megaton of TNT, in energy. A nuclear bomb.
Mammiform clouds falling from the underside of the overshoot disk in the same cloud. I have to say they look a bit like Rayleigh-Taylor instabilities, but I don't think that is the accepted origin of mammiform clouds. Wispy streaks show precipitation from this massive plug of water shoved up into a dry place and you can see the spiral structure in the disk, albeit highly foreshortened. About an hour before sunset, you can see low-level convective clouds near the ground.
I put the full photo set here
Fresh (<24 hr) lava erupted from the flanks of Kilauea. Fresh lava appears silvery because it is coated in glass formed by rapid cooling of the surface skin. After a few days the glass breaks off by thermal fracture and mechanical stresses, and the surface becomes dull. The cool surface layer here is about 10cm thick - glowing red lava was visible underneath several of the sack-like bags. The surface did not deform under my weight and there is no danger of sinking in because the lava is dense, but it's so hot you could easily die from making contact through the conductively-cooled crust. Even the radiant heat from this patch was intense.
Viscous flow in a 2ft wide section of freshly erupted lava, still slightly glassy, with thermally fractured plates littering the scene. The color in this picture is quite accurate. Looks good in the zoom tool.
Dendritic desert drainage channels highlighted by hardy shrubs. Approaching Phoenix, Az.
Los Angeles from the south at about 5000 ft at 9am. The invisible coast is horizontal about 1/5 the way up from the bottom. Foreground cloud is the marine layer, which extends inland a few km. Haze fills the low region bounded by the fold mountains at the back of the basin. The passenger behind me said "look at all that smog", but none of it is smog. I frequently hear that from people. But when I see real yellow smog, in SF, Salt Lake City, Baltimore....others never mention it. Notice the 767 descending on the left side of the picture.
Wildfire, northern California, facing east from a 737 at 32,000 ft headed north. I saw about 6 distinct fires in the course of a 2.5 hr flight. This was the biggest one.
Markings in Ying's garage. The pattern resembles convection cells, especially solar granulation patterns. I suspect that these *are* formed by convection, presumably in wet concrete self-heated by the exothermic hydration reaction. Largest cells here are about 8cm across. The cells extended over about 2 meters of the concrete floor: this is the most distinct portion.
Chocolate, showing fat separation from storage at too high a temperature. About a cm-sized piece.
Meandering river trapped between mountain ridges, west of the Massanutten, Virginia. The strange thing is that wide meanders imply slow flow and small slope, but the terrain around the river looks quite lumpy. Looking south-west in the middle afternoon.
Meanders abutting linear ridge mountains. The picture was taken into the sun through a dirty airplane window, and has been stretched. Airplane was over Front Royal, Virginia: the Massanutten ridges represent an eroded syncline. My puzzlement here is that the sinuous river shape is normally formed on a nearly flat plane, but here it seems to cut into quite steep slopes. The left and right sides of the wave are symmetric, as well, which doesn't seem consistent with the asymmetry in the rock, left vs. right.
Lunar lowlands (Apollo 11 soil sample on the left) and lunar highlands (Apollo 16 sample on the right). Note the difference in albedo. Dishes are about 10cm in diameter.
Top-side view of stratus clouds with weakly developed convection evidently capped by a temperature inversion (hence the flat top). This was "marine layer" cloud over Los Angeles when we took off. It was perhaps 1000 ft - 1500 ft thick. The cloud continued unbroken to Hawaii, but the character, especially the degree of convection, changed with distance.
View of the same clouds a couple of minutes later from a greater altitude.
The orange layer is real but it's hard to see what might have caused it. The picture was taken far from the coast (maybe 200 or 300 miles) and the orange layer is strongest towards the west (i.e. even further from land).
Organized convection in stratus clouds over the Pacific. I guess these are classified as stratocumulus clouds. By this time the sun had been up all day, causing the more pronounced overturn.
Dust devil, maybe 70 m tall.
Burned pine tree bark, Yosemite. Region about 1 ft across.
Convergent cloud shadows viewed from a plane descending into murky skies above Boston. The 767 shadow is visible as a tiny dot at the convergence point (the antisolar point).
Counterpart to this phenomenon in which waves and ripples focus and defocus sunlight, casting "shadows" into the deeper water that appear convergent about the sun-viewer line. The black blob is the shadow of my head. The black region is the shadow of Santa Barbara pier, about 25 feet above the water. The bright specks are glints. The water-level field of view here is about 30 feet.
Exfoliating limestone, Wupatki National Monument, near Flagstaff, AZ.
Strange, almost vine-like landscape on hills next to the town of San Lucas, CA (south of San Jose). The characteristic brown color is of the lifeless hill surface but where it is disturbed, a bright white material shows through. Some of the white stuff has spilled down onto the green fields at the bottom, showing its powdery nature. The white channels seem to be man-made but google maps shows that they are not. They are just naturally eroded channels exposing this bright material.
Fresh sand ripples, Goleta beach. Shadow for scale.
Sand ripples, shoe-print for scale.
Multiple dendritic drainage patterns, Goleta.
Smoke from a fire (left of house) trapped at a thermal inversion about 3 m above the ground, about 1 hr after sunrise. Flagstaff, from a speeding car.
Smoke from a large fire trapped at a thermal inversion maybe 100 m above the ground. About 3pm, El Centro.
Large scale K-H wave-train on a cloud layer near Belfast, just after sunrise, and presumably caused by flow over mountains.
Line of volcanoes, near Seattle. Picture by Jing.
Rock strata, Point Dume
Weathered surface of a copper statue in Juan Carlos park, Madrid. Width about 1 meter. The white spot is probably an attempt to clean the black mark, which might be graffiti. The rest of it is all natural. When zoomed it looks like a planetary surface. Staggering, actually.
Downtown LA under low cloud (stratocumulus), from a 757 landing to the west before sunset.
Icebergs and sea ice, northern Canada, Hudson Straights, viewed from a 747 at 36,000 ft, with oblique illumination (maybe 10 degrees solar altitude). Looking north. Region shown is probably a mile across.
Great Salt Lake, mountains, powerplant and factory plumes capped by thermal inversion, ship. A highly oblique view from 39,000 ft.
Sinuous river channels highlighted by snow, in a glacially scoured, sediment-filled valley, Montana.
Sulphurcles - vertical sulphur structures a few cm long produced by condensation from rising vapor at a hot vent. Sulphur Banks - Kilauea.
Gravel bar, Blakeney Point
Differential spheroidal weathering of a composite rock containing hard nodules, Kitt Peak, Az.
Salt evaporation pond, San Francisco Bay
Colorful lava on Kilauea
Inversion over wildfire, northern CA
Periodic gravel mounds on Goleta beach. Wavelength is about 10 meters and there were 6 of them, exposed as little patches below the berm, only on this section of the beach. I've not seen them before. What instability determines the wavelength?
More periodic gravel patches, wavelength about 7 or 8 meters, a few miles south of Los Osos. Maybe the instability occurs when water on the beach finds a quick way to drain, making a fast-flow channel that strips pebbles. The periodicity might come from the relative ease of draining sideways into the nearest channel vs. finding a new channel straight to the sea. If so, the spacing should depend on beach slope, with steeper beaches having smaller pebble mound wavelengths. But it must depend on the pebble size, shape and many other things. And they don't occur everywhere.
Sandbar blocking the Moro Bay estuary near Los Osos, CA. Moro Rock in the distance.