Controlled irradiative formation of penitentes.

  title={Controlled irradiative formation of penitentes.},
  author={Vance Bergeron and C. Berger and Meredith D. Betterton},
  journal={Physical review letters},
  volume={96 9},
Spike-shaped structures are produced by light-driven ablation in very different contexts. Penitentes 1-4 m high are common on Andean glaciers, where their formation changes glacier dynamics and hydrology. Laser ablation can produce cones 10-100 microm high with a variety of proposed applications in materials science. We report the first laboratory generation of centimeter-scale snow and ice penitentes. Systematically varying conditions allows identification of the parameters controlling the… 
Physical processes causing the formation of penitentes.
This work investigates the physical processes at the initial stage of penitente growth and performs the linear stability analysis of a flat surface submitted to the solar heat flux and found that it is controlled by aerodynamic mixing of vapor above the ice surface.
Formation of spiky structures in high-altitude snow patches: penitente tilting
Penitentes are spikes formed on the surface of the snow, which are present typically at high altitude in the Andes and Himalayas. They are a consequence of a thermodynamic instability, as a result of
Spiky ice and penitente tilting
Under certain conditions, at high altitude, the surface of snow develops spike-like structures known as penitentes. This is a rather counterintuitive phenomenon, which is a consequence of surface
3D surface properties of glacier penitentes over an ablation
Penitentes are a common feature of snow and ice surfaces in the semi-arid Andes where very low 10 humidity, in conjunction with persistently cold temperatures and sustained high solar radiation
Penitentes as the origin of the bladed terrain of Tartarus Dorsa on Pluto
Simulations, based upon a recent model representing conditions on Pluto, show that deepening penitentes reproduce both the tri-modal (north–south, east–west and northeast–southwest) orientation and the spacing of the ridges of this bladed terrain.
Penitente formation is unlikely on Europa
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA. *e-mail: Europa’s icy surface is unknown at the metre scale. Hobley et al.1 argue that 15-m-tall
Sublimation as a landform-shaping process on Pluto
Fields of pits, both large and small, in Tombaugh Regio (Sputnik Planitia, and the Pitted Uplands to the east), and along the scarp of Piri Rupes, are examples of landscapes on Pluto where we
Formation of glacier tables caused by differential ice melting
Abstract. Glacier tables are structures frequently encountered on temperate glaciers. They consist of a rock supported by a narrow ice foot which forms through differential melting of the ice. In
Formation of metre-scale bladed roughness on Europa’s surface by ablation of ice
On Earth, the sublimation of massive ice deposits at equatorial latitudes under cold and dry conditions in the absence of any liquid melt leads to the formation of spiked and bladed textures eroded
Bladed Terrain on Pluto: Possible origins and evolution
Abstract Bladed Terrain on Pluto consists of deposits of massive CH 4 , which are observed to occur within latitudes 30° of the equator and are found almost exclusively at the highest elevations (> 2


Characterization of the progressive growth of columns by excimer laser irradiation of silicon
The growth mechanism of columns produced by excimer laser irradiation of a silicon target is investigated. The micrometric columns are formed by a cumulative process with well-defined steps. The
Excimer-laser ablation and micro-patterning of ceramic Si3N4
3N4 has been investigated. The ablation threshold in air, Φth, is around 0.3±0.1 J/cm2 with ArF- and 0.9±0.2 J/cm2 with KrF-laser radiation. With fluences Φth<Φ<4 J/cm2 the irradiated surface is
Theory of structure formation in snowfields motivated by penitentes, suncups, and dirt cones.
  • M. Betterton
  • Geology, Medicine
    Physical review. E, Statistical, nonlinear, and soft matter physics
  • 2001
A minimal model for the formation of ablation morphologies as a function of measurable parameters is formulates and the linear stability of this model is considered and an interesting result is the prediction of a dirt-induced traveling instability for a range of parameters.
Formation of conical microstructures upon laser evaporation of solids
Abstract.The formation and development of the large-scale periodic structures on a single crystal Si surface are studied upon its evaporation by pulsed radiation of a copper vapor laser (wavelength
Investigation of conical structures created by ArF excimer laser irradiation of polycarbonate
Conical structures develop on the surface of ArF excimer laser ablated polycarbonate between 20 and 600 mJ/cm2. The cause of this is that the particulate impurities (which are responsible for the
We report that silicon surfaces develop an array of sharp conical spikes when irradiated with 500 laser pulses of 100-fs duration, 10-kJ/m2 fluence in 500-Torr SF6 or Cl2. The spikes are up to 40-μm
Formation of ‘‘intrinsic’’ surface defects during 248 nm photoablation of polyimide
Photoablation of polymers by pulsed excimer laser radiation is commonly believed to be a controlled layer‐by‐layer removal process. A mass spectrometer was used to monitor neutral species ejected
Microcolumn development on titanium by multipulse laser irradiation in nitrogen
We report the growth of titanium nitride microcolumns under multipulse Nd:yttrium aluminum garnet ( 1.064 m, ∼ 300 ns, 30 kHz) laser irradiation of titanium targets in nitrogen atmosphere. The laser
Structural origin of surface morphological modifications developed on poly(ethylene terephthalate) by excimer laser photoablation
The ablation of poly(ethylene terephthalate) (PET) by Ar‐F laser radiation has been studied at different fluences for amorphous and semicrystalline samples by scanning electron microscopy (SEM) and
Femtosecond laser ablation of polytetrafluoroethylene (Teflon) in ambient air
Teflon, polytetrafluorethylene (PTFE), is an important material in bioscience and medical application due to its special characteristics (bio-compatible, nonflammable, antiadhesive, and heat