fair weather cumulus over Estancia, New Mexico
photo Sally Beers
Since thermals originate as the result of differential heating of the ground it should be possible to generate thermals in a desired location and configuration by creating areas of higher thermal absorption in an otherwise uniform ground, basically creating black spots on a lighter colored surface. These black spots would would trigger thermals which ultimately would produce visible clouds higher in the atmosphere. Initially it is proposed to apply circles of a dark asphalt-like coating in selective locations of an otherwise flat and highly reflective desert surface such as a dry lakebed or salt flat. These circles would be made by spraying a commercial pavement treatment such as those used for asphalt coating or chip sealing roads. These coatings are relatively low cost and can be applied economically and quickly over large areas using applicator trucks which deliver a computer-controlled sprayed film of material as they drive along. This becomes an important concern due to the size requirements of these thermal trigger zones. Sailplane pilots around the world are adept at identifying naturally occurring "hot spots" and creation of a thermal typically requires features with sizes measured in the hundreds of feet up to more than a mile. A commonly trigger for thermals in the area where I fly are crop fields where circular irrigation rigs are used which can be up to a mile in diameter. Perhaps the smallest sites for triggering thermals are large blacktop parking lots, which can be as small as 100 yards across.
Two preliminary studies would be completed to determine the basic vocabulary available to cloud compositions. Two major parameters are of interest in determining the configuration of the ground trigger zones and the effect on the resultant cloud formations. First is the surface area of the trigger zone. (It is assumed that circular trigger zones will be used.) Study of atmospheric science literature will determine if there is an optimal size area for these trigger zones and the effects of area and other trigger zone parameters on the resultant thermal and cloud. It will almost certainly be somewhat site specific subject to parameters such as the radiant energy absorption difference between the coating and the native surface, altitude of the location, average humidity and temperature, the dominant type of local air mass, and sunlight incident energy. The initial study will be a test of a line of trigger zones of increasing diameter, centered upon a size determined to be optimal from the literature, spaced several diameters apart, to determine if there is an optimal size for a ground trigger area in terms of predictability of the thermal and persistence of the visible cloud.
The performance of the various trigger zones would be analyzed by time lapse video of the test site over a period of several months with varying climate. If possible it would be very desirable to measure the performance of these trigger zones using doppler radar as well, to be able to measure thermal size and velocity when the effects of the trigger zone are still invisible, below the condensation level. It is well known that these thermal-driven cumuli cycle throughout the day, experiencing repeated development and decay over periods of hours. It may be the case that various sizes of trigger circles may be employed to obtain differing cloud qualities such as size (the extent of vertical and horizontal development), stability and longevity, and optical properties such as opacity and brightness.
The second parameter of interest is the spacing between adjacent trigger zones. From personal soaring experience and simple common sense it is obvious that thermals which are located in close proximity to each other interact, often deleteriously. The rising, swirling columns of air can disrupt each other, impeding cloud development. Again the scientific literature will be examined to see if any work has been reported on the effects of spacing between trigger zones. It is desirable to be able to place trigger zones sufficiently close so as to be able to make connected cloud shapes, lines and curves, as opposed to the single point of an isolated cloud. This second study will involve one or more lines of trigger zones, each line having zones of the same size, but at graduated spacing ranging from less than a diameter to several diameters. The effect of proximity of the zones will be studied to determine how closely placed zones may be in the interest of making connected clouds without negatively impacting cloud formation.
This is the title of the first piece in the series. The work consists of an artificial cloud formation forming the intersection of two line segments. This is effectively one of the most minimal visual artifacts which can conclusively demonstrate deliberate compositional intent. It is also a recurring image in early land art, possibly for that reason. Obviously, naturally occurring clouds can form points of various sizes and these points of development combine to form irregular amorphous masses. What is not so well know is that due to natural phenomena which are still not completely understood, clear air cumulus, particularly in desert climates, can form pronounced linear patterns which can extend for many miles. These are called "cloud streets" by soaring pilots due to their use as virtual roads in the sky for sailplanes. These configurations are thought to be the result of moderate winds displacing thermals and their attendant clouds which are being continuously generated by a particularly strong fixed ground trigger. There may be secondary effects relating to additional triggers being generated by the downwind shadows of these clouds, contributing to additional linear development. At any rate, lines of clouds do, in fact occur naturally. Hence, the choice of the intersection of two lines as the initial work.
The work consists of a ground configuration of circular trigger zones arranged in the form of a X or plus sign +, each line being tentatively 2 and 1/4 miles in length and composed of five 1/4 mile diameter circular zones spaced at two diameters. This configuration should produce at various times of day a configuration of clear air cumulus in the form of a cross, floating between 3 to ten thousand feet above the desert floor. The form has inescapable religious significance but is in fact one of the more simple shapes which can be used to signify deliberate marking or drawing. I like to think of pre-figurative primitive art and what the earliest drawing might be considered or look like could we find it. Also of interest are the drawings of very young children. It should be noted that the largest Christian cross in the world is located in West Texas and that might make an interesting location for the work. The work is definitely intended for the continental US, specifically the southwest. Perhaps it would be better to consider it an X, as in "x marks the spot", with the obvious intimations of a target or crosshairs. Of course the American desert southwest is the site of early atomic tests. An interesting locus for the work would be at Trinity Site in New Mexico, the location of the first atomic test.
The form will probably be far from regular more often than not due to the effects of winds, local micrometeorological variations, the effects of shadows, and the lack of complete predictability of the very mechanism of cloud generation itself. On many days the atmospheric conditions will not be right for cloud development at all. On other days, high winds may destroy the order of the thermals rising from the desert floor before they reach cloud base, destroying any perceptible organization in the visible clouds. Also, thermals certainly will not continuously trigger from the ground from all sites simultaneously. Clouds may appear intermittently at random locations along the cross, with randomly occurring cycles of development and decay throughout the shape. It may well be that a complete cross pattern may itself only be visible in time-lapse photography of the site except at very rare times.
Unlike the Reentry Pieces, the Cloud Pieces are not purely ephemeral. If properly prepared, the site may have a life as an organized cloud trigger of up to 10 years, as that is the life of the typical application of the road sealing surfaces which would be used. Another significant limit to life of the site would be the influx of wind-borne dust, which would gradually envelop the trigger zones, destroying the solar absorption and resulting thermal differential. This could be addressed by periodically blowing or sweeping the invading dust from the zones using a helicopter.
The second piece in the series consists of an artificial cloud formation in the shape of the outline of a square. This is also one of the most minimal visual artifacts which would conclusively demonstrate deliberate compositional intent. The number of line segments has now doubled to four, and they join at their endpoints instead of their centers. The box forms a frame of the site, a boundary, as well as a shape. It is a play on the idea that clouds, perhaps as amorphous an entity as has ever existed, are being used as a container, a boundary, a containment. It affirms the idea that once a natural phenomena can be synthesized it can be used to delimit and contain space. Continuing the nuclear age line of inquiry, perhaps the cloud box site should be at one of the large nuclear waste disposal sites in the southwest, such as WHIPP in New Mexico or the Yucca Mountain site in Nevada. The idea of a cloud box is sort of like attempting to contain the nuclear genie in a bottle. It is also evocative of the difficulty of forming the "magnetic bottle" required to contain nuclear fusion, the long-term salvation from large scale use of fossil fuel as well as the much dirtier nuclear alternative of fission reactors.
The work consists of a ground configuration of circular trigger zones arranged in the form of a square, each side being tentatively 3 and 1/4 miles in length and composed of a line of 7 circular zones 1/4 mile in diameter spaced at two diameters. This configuration should produce at various times of day a configuration of clear air cumulus in the form of a square, floating between 3 to ten thousand feet above the desert floor. As with the cloud cross, the form will not often not be regular or even identifiable but may partially appear then decay as another part appears due to the unsynchronized thermal cycles of various portions of the perimeter
The title is also a reference to the imaginary volume in the sky in which aircraft aerobatic competitions are conducted, the "aerobatic box" is a prescribed volume in the shape of a cube, 1 mile on a side, in which all aerial maneuvers must be completed. The work is most definitely a box, with an opaque floor (the ground) with a very visible geometric definition of its bound in the form of the circumscribing dots of the trigger zones. The sides of the box are formed by the invisible rising air currents of the thermals, and the top of the box is marked by the formation of clouds at the condensation level and above. Except in absolutely still air the box will never be a regular cube with orthogonal sides but will be trapezoidal in elevation from the effects of wind. Since the height of cloud base is a naturally occurring phenomena, the height of the box will vary from day to day, sometimes being tall and narrow in aspect, and sometimes, when the cloud base is very low, being short and broad.
The final Cloud piece is Cloud Array, and consists of a regular square array of trigger zones on the ground measuring eight rows by eight columns, or 64 individual trigger zones. Each trigger zone, in addition to being composed of an absorptive material sprayed on the ground, is covered by a remotely controlled louvered shade, allowing it to be in effect turned on, off, or set to some intermediate, partial setting. These trigger zones then become the equivalent of pixels in a digital drawing, with the ability to generate cloud compositions digitally. Any composition, so long as it can be represented by this 8 by 8 matrix, can be displayed. Cloud Array is not really a composition but a drawing machine, capable of many compositions, 2**64 in fact, or 18,446,744,073,709,551,616 to be precise. And that is static images. It could be used for very long term animations, providing a vastly extended repertoire.
Since the cloud array can form many images it takes on an element of signalling and communication, even language. The louvers over each circular trigger zone are like the louvers on a ships semaphore lantern. One can think of them as sending some sort of semaphoric message into space. They also evoke Native American smoke signals, except now organized into a regular array or chorus.
The Cloud Array continues the process begun on the Reentry Series of mimicking the development of electronic display drawing. While the Reentry Series compositions work very much like a vector display, the Cloud Array functions as a raster display, with the composition being built up of discreet "cloud pixels". It is conceptually similar to a contemporary flat plasma panel or LCD display. The choice of resolution is a homage to computer graphics, using familiar binary powers of 2 and the ubiquitous 8 bit byte as a common unit of information. The very low resolution of the device evokes both very early computer graphics display devices as well as the coarse grids of points of light involved in attempts to provide artificial sight in the blind using direct stimulus of the optical cortex.
As a purely technical note, the element of remote control provides for at least two interesting capabilities. First, the array could be changed over the course of a day, resulting in a time-varying composition as suggested above. Secondly, if feedback from doppler radar were employed, it might be possible to more accurately render the desired composition, if desired, modulating the louver over each trigger zone to control the amplitude and timing of the resultant thermal to more closely synchronize the formation of the cloud composition.
Computer graphical renditions of various cloud configurations will be developed as maquettes of the Cloud Pieces. In addition, time lapse studies will be made of cloud formation at a variety of locations. This would be a related and intersecting effort with the Time Landscape Series.
5/9/04 - 5/12/04
Estancia, New Mexico