The histories, written by Irish monks, over 1,200 years, have proved to be a useful resource to researchers who were examining climate change in relation to volcanic explosions.

The volcanic ash cloud emanating from Iceland has impacted service at several of Ireland’s airports on Sunday.

Donegal, Sligo and Knock airports will be operating on restricted service from 3 p.m. local time, says the Irish Aviation Authority.

Any further changes in service on these three western airports will be confirmed later today.

For now, Waterford, Cork and Dublin airports will remain open until 1 p.m. local time on Monday.

Shannon will remain open until at least 7 a.m. local time Monday.

Fluctuating weather patterns could bring the ash cloud over Ireland again over the coming days, with the west of the country most likely to be impacted.

Transatlantic flights may fall victim to the latest weather patters, and all passengers are strongly advised to check with their airlines before heading to the airport.

Aer Lingus and Ryanair have had to cancel numerous flights to mainland Europe because of the ash cloud.