It is important to describe the surface, and its properties, as well as possible. To do this SURFEX uses elevation data (from the GTOPO3 database of USGS), data on sand- and clay fraction in soil (from the HWSD database of FAO) and data on land surface parameters (from the ECOCLIMAP-II).
SURFEX
Figure 1. The processes simulated with the model SURFEX (from the SURFEX website).
The current set-up
/weather/articles/nr/3232
scientists at Gígjökull.
[No scientific overflight today.]
Eruption plume:
Height (a.s.l.): Estimated from web-camera views and observers on the ground at an
elevation of 4–5.4 km (13–18,000 ft). Clouds of ash at lower elevations
observed drifting south-east of the eruption site. No verifiable
detections from the weather radar at Keflavík Airport.
Heading: South-east from
/media/jar/2010-05-02_En-IES_IMO.pdf
• Analyse future snow scenarios
Introduction Data & Methods Results
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/media/ces/Dyrrdal_Anita_CES_2010.pdf
subcatchments vhm 167 and vhm 269) and the non-glacier covered watershed Sandá í
Þistilfirði vhm 26. ................................................................................................................. 9
Figure 2. Elevation distribution for Sandá í Þistilfirði (vhm 26, blue curve) and Austari-
Jökulsá (vhm 144, red broken curve
/media/ces/2010_016.pdf
.................................................................................................................. 10
Figure 4. Elevation distribution for Sandá í Þistilfirði (vhm 26, blue curve) and Austari-
Jökulsá (vhm 144, red broken curve). .................................................................................... 16
Figure 5. Comparison of mean yearly temperature 1961–2005 for Sandá í Þistilfirði (vhm
26); an interpolation
/media/ces/2010_017.pdf
was derived from
observations in the area of Swiss Camp (h is the surface elevation in m a.s.l):
τcl = 1.0 − 0.78n
2 exp(−0.00085h) (3)
3.2 Validation Procedure
Implemented in the mass balance model is the comparison of the RCM-data (= the model
input) to observations from weather stations on the ground. The observations are compared
to the values of the RCM grid-cells they are located in. Before
/media/ces/ces_geus_paakitsoq_full_report.pdf
caldera
covered by 150- to 250-m-thick ice (Figure
1). Its highest peak, Grímsfjall, on the southern
caldera rim, reaches an elevation of 1722 m.
Volcanic eruptions there, numbering several
per century, are phreatomagmatic because
of the ice cover, and they usually persist for
days to weeks. Geothermal activity continu-
ously melts the overlying ice, and meltwater
accumulates in a subglacial
/media/jar/myndsafn/2005EO260001.pdf
of validation data.
COMPARISON WITH GLACIOLOGICAL DATA
The spatial variability of the mass balance on large ice masses, such as
Vatnajökull and Langjökull ice caps, can be mapped given data along several
profiles extending over the elevation range of the ice caps. Mass balance has
been observed on parts of Vatnajökull ice cap in SE-Iceland since 1991 (Björns-
son et al., 1998) and from 1996
/media/ces/Paper-Olafur-Rognvaldsson_91.pdf
elevation contour lines are drawn at 1000 mASL, indicating roughly
the extent of the glaciers.
15
3 Radiation fluxes at the surface
With increasing time past the summer solstice (20 June 2012), the solar energy per unit area
received at the Earth’s surface, for the same cloud and snow conditions, decreases due to the
shorter days and lower sun altitude angles. The characteristics of the solar cycle
/media/vedurstofan/utgafa/skyrslur/2015/VI_2015_006.pdf