Sentences with phrase «balance measurement network»

Not exact matches

The highest density network is probably the highest measurement density ever used in mass balance observations.

The annual balance in meters of water equivalent determined from field measurements networks of varying number of measurement sites on Columbia Glacier.

On Columbia Glacier, we used a measurement network with a maximum density of 375 points / km2, and a maximum spacing between points of 90 m and a mean spacing of 45 m. Annual mass balance (1984 - 1998) was typically determined on Columbia Glacier from a measurement network with a spacing of 187 points / km2 (Pelto, 1996), and a mean spacing of 50 m.

However, the consistency of the error for each year indicated by the parallel nature of the annual balance trendlines for the varying point networks suggests even greater accuracy was possible if the overall glacier balance distribution has been determined at some time using a denser measurement network (Figure 5).

On Columbia Glacier in the North Cascades, Washington and Lemon Creek Glacier Juneau Icefield, Alaska, we determined annual mass balance from measurement networks of varying density.

We calculated the mass balance for each measurement network simply from the mean of all the observations, without biasing the results according to the representativeness of the specific sites.

We had the advantage of already understanding the overall mass balance pattern of each glacier in selecting measurement networks that would provide the most representative coverage for the glacier given the total number of measurements in each sample (Pelto, 1996; Miller and Pelto, 1999).

To ascertain the annual balance of a glacier from a sparse network of observations is optimized by detailed mapping of mass balance across the glacier determined from a high - density measurement network during several years.

Cogley (1999) pointed out that with a measurement network spaced at 50 - 100 m apart the largest source of uncertainty is the error in actual point mass balance measurement (> 0.05 m), and sampling error is negligible.

Determining the most efficient sampling pattern and identifying the overall accuracy of the sampling network is key to assessing error in annual mass balance measurement.

We compared the mass balance results from a dense network of measurements with variously sparse networks, to determine the error resulting from using increasingly sparse networks.

Each network of points was chosen to provide the most even distribution possible of measurements across each glacier, given the known mass balance pattern.

This 14 glacier monitoring network, covering an area of 14,000 km2, represents the most extensive network of mass balance measurements for alpine glaciated areas in the world.

This paper focuses on the latter two programs, which together provides the most extensive regional network of glacier annual balance measurements in the world.