Development of a Quality-Controlled and Homogenised Long-Term Daily Maximum and Minimum Air Temperature Network Dataset for Ireland

Carla Mateus,Aaron Potito

doi:10.3390/cli9110158

Abstract

Accurate long-term daily maximum and minimum air temperature series are needed to assess the frequency, intensity, distribution, and duration of extreme climatic events. However, quality control and homogenisation procedures are required to minimise errors and inhomogeneities in climate series before the commencement of climate data analysis. A semi-automatic quality control procedure consisting of climate consistency, internal consistency, day-to-day step-change, and persistency tests was applied for 12 long-term series registered in Ireland from 1831–1968, Armagh Observatory (Northern Ireland) from 1844–2018, and for 21 short-term series dating to the mid-19th century. There were 976,786 observations quality-controlled, and 27,854 (2.9%) values flagged. Of the flagged records, 98.5% (n = 27,446) were validated, 1.4% (n = 380) corrected and 0.1% (n = 28) deleted. The historical long-term quality-controlled series were merged with the modern series quality-controlled by Met Éireann and homogenised using the software MASHv3.03 in combination with station metadata for 1885–2018. The series presented better homogenisation outcomes when homogenised as part of smaller regional networks rather than as a national network. The homogenisation of daily, monthly, seasonal, and annual series improved for all stations, and the homogenised records showed stronger correlations with the Central England long-term temperature series.

Highlights

The Island of Ireland has a great heritage of meteorological observations dating back to the 17th century, the majority of the records remain as paper data-sources which need to be rescued to fill critical gaps in climate research [1]
A total of 21 short-term and long-term daily maximum air temperature (MAX) and daily minimum air temperature (MIN) series registered in the Island of Ireland and dating back to the 19th century were rescued from multiple data-sources and digitised [2,3]
The quality-controlled and homogenised MAX and MIN series as part of regional networks that were produced in this research will be employed to calculate trends and assess the frequency, duration, intensity, and distribution of extreme air temperature indices recommended by the ETCCDI, as well as heat waves and cold waves dating back to the 19th century [4,5,6]

Summary

Introduction

The Island of Ireland has a great heritage of meteorological observations dating back to the 17th century, the majority of the records remain as paper data-sources which need to be rescued to fill critical gaps in climate research [1]. A total of 21 short-term and long-term daily maximum air temperature (MAX) and daily minimum air temperature (MIN) series registered in the Island of Ireland and dating back to the 19th century were rescued from multiple data-sources and digitised [2,3]. Quality control of instrumental datasets involves checking for data keying errors and detecting other errors which can be deleted or corrected to ensure the accuracy and consistency of data. Data validation applies quality control tests to flag, and subsequently inspect, suspicious data [8]

Methods

Results

Discussion

Conclusion