London scoping - ukcip

Final Report
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Predictor A variable that is assumed to have predictive skill for another
variable of interest, the predictand. For example, day–to–day
variations in atmospheric pressure may be a useful predictor of
daily rainfall occurrence.
Radiative forcing The change in net vertical irradiance (expressed as Watts per
square metre) at the tropopause due to an internal change or a
change in the external forcing of the climate system, such as, for
example, a change in the concentration of carbon dioxide, or the
output of the Sun.
Random See stochastic.
Regional Climate Model
(RCM)
A three–dimensional, mathematical model that simulates regional
scale climate features (of 20–50 km resolution) given
time–varying, atmospheric properties modelled by a General
Circulation Model. The RCM domain is typically ‘nested’
within the three–dimensional grid used by a GCM to simulate
large–scale fields (e.g. surface pressure, wind, temperature and
vapour).
Regression A statistical technique for constructing empirical relationships
between a dependent (predictand) and set of independent
(predictor) variables. See also black box, transfer function.
Relative humidity A relative measure of the amount of moisture in the air to the
amount needed to saturate the air at the same temperature
expressed as a percentage.
Resolution The grid separation of a climate model determining the smallest
physical feature that can be realistically simulated.
Scenario A plausible and often simplified description of how the future
may develop based on a coherent and internally consistent set of
assumptions about driving forces and key relationships.
Scenarios may be derived from projections, but are often based
on additional information from other sources, sometimes
combined with a ‘narrative story–line’.
SDP Strategic Development Plan.
Specific humidity The ratio of the mass of water vapour (in grams) to the mass of
moist air (in kilograms) in a given volume of air.
Station The individual site at which meteorological measurements are
systematically observed and recorded.