Sentences with phrase «ablation surface»

We used satellite and in situ technologies to assess surface drainage conditions on the southwestern ablation surface after an extreme 2012 melting event.

The probe is driven through the snowpack until the previous ablation surface is reached.

In the North Cascades the ablation surface of the previous year is always marked by a 2 - 5 cm thick band of dirty firn or glacier ice.

Not exact matches

Dresselhaus also analysed graphite using techniques including laser ablation in which energy from a laser beam is used to strip material from a surface.

Dresselhaus also analyzed graphite, using techniques including laser ablation, in which energy from a laser beam is used to strip material from a surface.

Therefore ablation (removal of the material from the surface of an object by vaporization, or other erosive processes) of the ear may be necessary.

If significant area becomes an ablation zone, then once the previous winters snow has melted, the surface is composed of old ice, which every year becomes older than the last.

Detailed studies of the energy balance and ablation of the Zongo and Chacaltaya glaciers support the importance of air temperature increase, and identify the increase in downward infrared radiation as the main way that the effect of the warmer air is communicated to the glacier surface [Wagnon et al. 1999; Francou et al, 2003].

Therefore, if conditions allow the glacier surface to warm to 0 C, the amount of ablation that can be sustained by a given energy input increases dramatically.

As the authors point out, even if the whole story comes down to precipitation changes which favor ablation, the persistence of these conditions throughout the 20th century still might be an indirect effect of global warming, via the remote effect of sea surface temperature on atmospheric circulation.

However, there is both theoretical and observational evidence that melting now occurs on the horizontal surfaces of the Kilimanjaro Northern Ice Field, and contributes to ablation [Moelg and Hardy 2004; Thompson et al 2002].

Even the admirable Revkin doesn't get it quite right: On horizontal surfaces, observations and modeling show a role for melting in both the baseline ablation and the sensitivity of ablation to precipitation and temperature; melting is the dominant ablation mechanism on vertical ice cliffs; and though Kaser et al find «no evidence» about rising temperatures, it is only because the in situ studies don't cover a long enough period to detect trends.

Though air temperature has so far remained below freezing, melting has begun to occur, and the glacier is suffering net ablation over its entire surface.

What is called surface mass balance refers simply to snowfall minus surface ablation (ablation is melting plus sublimation).

On marine terminating outlet glaciers the mechanisms to trigger thinning is surface ablation causing thinning, and potentially basal melting, though not yet observed (though see this recent paper by Holland et al, 2008).

In addition to the measured retreat we have measured the surface profiles of these glaciers, measured annual snowpack on the glaciers and annual ablation.

Annual ice and firn ablation (firn and ice net balance: Mayo et al., 1972) is determined using ablation stakes drilled into the glacier surface and simultaneously checked on the same date in late September.

The amount of runoff provided by a glacier is the product of its surface area and ablation rate.

Each program monitors ablation during specific time periods using stakes emplaced in the glacier surface.

The accumulation area decreased by 24.8 %, while ablation area increased by 17.7 % with nearly 6 % increase in debris - cover surface in ablation zone in 1958 to 2011.

Surface ablation and basal ice ablation are determined by the climatic and oceanographic conditions at near the glacier front.

D denotes change in ice discharge while SMB denotes the net surface mass balance (accumulation minus ablation).

This is their sensitivity Achilles Heel: relatively little increases in melt can expand the ablation zone appreciably given the low surface slopes and low accumulation rates.

Ablation stakes made of plywood strips 10 - cm wide and marked with alternating black and white 10 - cm squares are planted in the ice near the buoy to indicate visually the amount of surface melting as the summer proceeds.

The specific surface mass balance is positive in the accumulation area and negative in the ablation area.

Ludicrous as it may sound to you, a rigorous system model of the effect upon surface temperatures from albedo changes due to snow / ice ablation will not have any feedback loop whatsoever back to the fundamental input of insolation.

Eventually, I will add an online surface budget computation, allowing the reader to play with various parameters and see how they affect the ablation.)

The energy available for ablation of a glacier is determined by the energy budget of the glacier surface, illustrated in the accompanying figure.

The surface mass balance observations similarly indicate that the ELA has migrated upwards at a rate of 44 m / a over the 1997 — 2011 period in West Greenland, resulting in a more than doubling of the ablation zone width during this period...»

van den Broeke, M. R., C. J. P. P. Smeets, and R. S. W. van de Wal (2011), The seasonal cycle and interannual variability of surface energy balance and melt in the ablation zone of the west Greenland ice sheet, Cryosphere, 5, 377 — 390.

We also need in situ measurements in the GrIS's ablation zone that can distinguish the relative contributions of different impurity types (e.g., black carbon, dust, algae) to albedo reduction as well as models that accurately simulate the GrIS surface energy balance and mass balance.