Scottish Road Network Climate Change Study: UKCP09 update Autumn 2011
3 Climatic variables investigated
The climate change variables targeted in this study are the same as those assessed in the Scottish Road Network - Climate Change study" (Scottish Executive, 2005). The identification of appropriate variables has not been re-visited as part of this study. As there are slight differences in the range of variables offered by UKCIP02 and UKCP09 it has been possible to include some variables which are not available in the earlier study. Conversely others have been lost. Table 3.1 tabulates the UKCP09 variables investigated.
| Variable | Assessed in this study | Comment |
|---|---|---|
| Annual mean temperature | √ | Available as standard UKCP09 output |
| Frost days | √ | Derived from weather generator output |
| Freeze-thaw | √ | Derived from weather generator output |
| Winter duration | √ | Derived from weather generator output |
| Temperature exceeding 25 ºC | √ | Derived from weather generator output |
| Temperature exceeding 30 ºC | √ | Derived from weather generator output |
| Growing season length | √ | Derived from weather generator output |
| Annual mean precipitation | √ | Available as standard UKCP09 output |
| Seasonal mean precipitation | √ | Available as standard UKCP09 output |
| 10-year extreme daily rainfall | √ | Derived from weather generator output |
| 2-year extreme daily rainfall | √ | Derived from weather generator output |
| Wettest day in a season | √ | Available as standard UKCP09 output |
| Soil moisture deficit | √ | Derived from weather generator output |
| Groundwater recharge | √ | Derived from weather generator output |
| Sea-level rise | √ | Available as standard UKCP09 output |
| Snow | x | Not available from UKCP09 |
| Extreme or average wind speed | x | Not available from UKCP09 |
As noted above, the climate variables offered by UKCIP02 and UKCP09 are not always directly comparable. Where necessary, reasonable interpretations have been made to allow a sensible comparison between UKCIP02 and UKCP09 projections. For the purposes of the current study, this is considered to be an acceptable approach.