Towards a Definitive Historical High-Resolution Climate Dataset for Ireland – Promoting Climate Research in Ireland

There is a constant demand from industry, research and governmental sectors for high-quality, long-term, gridded climate datasets with high spatial and temporal resolution for conducting climate research in Ireland. Such datasets have the potential to be utilised in a wide range of applications, including agricultural, hydrology, public health, energy (wind, wave and solar), socio-economic planning and fundamental studies in observed climate change trends and variability. However, with the exception of temperature and precipitation, spatially and temporally homogeneous, multi-decadal, gridded observational climate datasets are not readily available for climate research applications in Ireland. Climatologically important variables, such as wind direction, humidity, soil moisture, evapotranspiration and radiation are measured at a limited number of weather stations.

Researchers at ICHEC and Met Éireann addressed this lack of homogeneous, long-term, gridded datasets by completing the following downscaled ERAInterim high-resolution simulations:

• ICHEC WRF with 2-km grid spacing
• ICHEC COSMO-CLM5 with 1.5-km grid spacings
• Met Éireann re-analysis (MÉRA) with 2.5-km grid spacings.

Each simulation covers the period 1981-Present and fields are archived at one-hour intervals. Table 1 provides an outline of the archived COSMO-CLM5 fields. The WRF and MÉRA archived fields are similar. Figures 1 presents preliminary validation results for rainfall.

The MÉRA simulation employed a data assimilation component which results in a more complete estimate of the atmospheric state that is both dynamically consistent and optimally close to observations. The benefit of such datasets is that they provide the best estimate of the four-dimensional atmospheric state, not only of the observed variables, but also the Essential Climate Variables (ECVs) and parameters which are not routinely monitored by observations.

A key component of the current project is to promote the use of these datasets and enhance climate research in Ireland. The datasets are currently being analysed and validated with the overall aim to produce a definitive historical climate dataset for Ireland. The climate data, together with assigned uncertainty estimates, will be made publicly available so that researchers, policy makers, Irish industry and the general public can utilise the datasets according to their specific needs. In addition, it is envisaged the datasets will be used as a basis for more-focused climate impact studies with a wide range of applications such as wind farm modelling, public health and socio-economic modelling.

If you are interested in learning more about the project or obtaining datasets, please contact jason.flanagan@ichec.ie