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Are the projections at sea level or are local topographical effects taken into account?
Do the projections include intense convective rainfall such as occurs in thunderstorms?
Does UKCP09 provide any information beyond 2100?
Does UKCP09 consider changes to the Gulf Stream (Meridional Overturing Circulation)?
How are the estimates of land movement used in the relative sea level projections derived?
How are the models used in UKCP09 weighted, and how sensitive are the projections to this weighting?
How can I deal with changes in UK since the 1961-1990 baseline period?
How do the projections in UKCP09 compare with those in UKCIP02?
How do the storm projections for UKCIP02 and UKCP09 compare? Does UKCP09 show an increase in the frequency, intensity and severity of storms?
How do I load the observed trends gridded data into ArcGIS?
How does the Met Office Hadley Centre model compare with other models?
How does UKCP09 model sea level rise?
How have Cooling Degree Days (CDD) and Heating Degree Days (HDD) been calculated in UKCP09?
What are the sources of uncertainty in the Marine & coastal projections?
What atmospheric processes and feedbacks are included in the UKCP09 modelling?
What does the frequency distribution associated with the sea level projections actually mean?
What methodology was used to generate Potential Evapotranspiration in the 11-member RCM?
What uncertainties exist with the sea level rise and storm surge projections?
What variables are available from the different UKCP09 terrestrial data sources?
Where can I find information on the coordinates and IDs of the grids?
Why is the baseline period for the sea level rise projections different from the UKCP09 1961-1990 baseline?
Why are the storm surge, sea level waves and multi-level ocean projections not probabilistic?
Why was the IPCC AR2 emissions scenario not used as the UKCP09 High emissions scenario?
Why can't I aggregate two grid cells together with the probabilistic data?
Will the PDFs incorporate the effect of natural multi-decadal variability as well as climate change?

How are the models used in UKCP09 weighted, and how sensitive are the projections to this weighting?

A set of global metrics of observed climate are used to weight the Met Office Hadley Centre models. The alternative global climate models are not weighted in UKCP09, and are considered equally valid.

In detail

The Met Office Hadley Centre models in the large ensemble which underpins the are weighted as described in the first FAQ, opposite. The alternative climate models are not weighted, for reasons explained in the second FAQ, opposite.

Last updated: Thursday, 05 July 2012

How are the models used in UKCP09 weighted, and how sensitive are the projections to this weighting?

In detail

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