Arctic cyclones have become more intense and longer-lived over the past seven decades

Datasets created and used for the paper:

Zhang, X., Tang, H, Zhang, J., Walsh, J. E., Roesler, E. L., Hillman, B., Ballinger, T. J. & Weijer, W. Arctic cyclones have become more intense and longer-lived over the past seven decades. Commun. Earth Environ. https://doi.org/10.1038/s43247-023-01003-0 (2023).

EnCAI-Jan1950-Dec2021.txt: Monthly Energy-based Arctic Cyclone Activity (EnCAI) Index from January 1950 – December 2021.

Count_SLP_Bins_Winter.dat: The Arctic cyclone count anomalies for winter (October – March) from 1950/51 – 2020/21.

Count_SLP_Bins_Summer.dat: The Arctic cyclone count anomalies for summer (April – September) from 1950 – 2021.

Duration_SLP_Bins_Winter.dat: The Arctic cyclone duration anomalies for winter (October – March) from 1950/51 – 2020/21.

Duration_SLP_Bins_Summer.dat: The Arctic cyclone duration anomalies for summer (April – September) from 1950 – 2021.

Freq_Winter_1985-86-2020_21.dat: Spatial frequencies of strong cyclones during winter (October – March) from 1985/86 – 2020/21.

Freq_Winter_1950-51-1984-85.dat: Spatial frequencies of strong cyclones during winter (October – March) from 1950/51 – 1984/85.

Freq_Winter_Diff.dat: Differences of the spatial frequencies of winter strong cyclones between 1985/86 – 2020/21 and 1950/51 - 1984/85.

Freq_Summer_1986-2021.dat: Spatial frequencies of strong cyclones during summer (April - September) from 1986 – 2021.

Freq_Summer_1950-1985.dat: Spatial frequencies of strong cyclones during summer (April - September) from 1950 – 1985.
Freq_Summer_Diff.dat: Differences of the spatial frequencies of summer strong cyclones between 1986 – 2021 and 1950 - 1985.

EGR.nc: Climatological mean Maximum Eady Growth Rate (EGR) for winter (October - March) from 1950/51 - 1984/85 and from 1985/86 - 2020/21; Climatological mean Maximum Eady Growth Rate (EGR) for summer (April - September) from 1950 - 1985 and from 1986 - 2021; Differences of winter and summer EGRs between the two multidecadal time periods.

z500.nc: Climatological mean 500 hPa Goepotential Height (GHT) for winter (October - March) from 1950/51 - 1984/85 and from 1985/86 - 2020/21; Climatological mean 500 hPa Goepotential Height (GHT) for summer (April - September) from 1950 - 1985 and from 1986 - 2021; Differences of winter and summer 500 hPa GHTs between the two multidecadal time periods.

z300.nc: The same as z500.nc, but for 300 hPa.

z50.nc: The same as z500.nc, but for 50 hPa.

PV300.nc: Climatological mean 300 hPa Geopotential Vorticity (PV) for winter (October - March) from 1950/51 - 1984/85 and from 1985/86 - 2020/21; Climatological mean 300 hPa Goepotential Vorticity (PV) for summer (April - September) from 1950 - 1985 and from 1986 - 2021; Differences of winter and summer 300 hPa PVs between the two multidecadal time periods.

Note: the data files ending with "txt" and "dat" are in ascii format and with "nc" are in NetCDF format.