Iceland-Lofotes-Difference-Index (ILD) 1957-2017

• Main Author: Jahnke-Bornemann, Annika
• Format: Dataset
• Language: English
• Published: 2019
• Subjects: climate index; Iceland; Lofoten; North Atlantic; ILD; pressure; low; Irminger Sea; Norwegian Sea
• Online Access: https://doi.org/10.25592/uhhfdm.638

The weather and climate change in the North Atlantic has a strong influence on Europe's weather and especially the position of steering lows is of great interest. In the long-term mean of atmospheric pressure in the North Atlantic appeared two regions with increased activity. These lows have a significant impact on the meridional heat flows to Europe. The two activity centres are located on the one hand over the Irminger Sea near Iceland and on the other over the Norwegian Sea near the Lofoten Islands. There is also a primary and secondary minimum in the long-term mean air pressure field at sea level. To study these minima, a climate index of the Iceland-Lofoten pressure difference (ILD index) was defined [Jahnke-Bornemann 2008, 2010]. The calculation of the index was carried out, analogous to the station-based NAO index [Hurrell, 1995], as the difference of the standardized atmospheric pressure anomalies of a defined Iceland and Lofoten region. This data set contains the monthly ILD-Index, calculated from mean sea level pressure (MSLP) fields from ECMWF Reanalysis data ERA 40 (9/1957-12/1978) and ERA Interim (1/1979-1/2017) for the period September 1957 to January 2017, with the reference period 01/1979-12/2000. The areas used for the calculation of pressure means are 70N to 72.5N, 13.5E to 15.75 E for Lofoten, and 60N to 63N, 35W to 38W for Iceland.