Joule heating rates in the Northern Hemisphere (JOIN ESA 4D Ionosphere project)

Gridded Joule heating rates in the Northern Hemisphere Joule heating rates in the Northern Hemisphere estimated in the Joule heating effects on ionosphere-thermosphere coupling and neutral density (JOIN) project as part of ESA's 4D ionosphere initiative. The dataset is related to the article "Joule Heating in the Northern Hemisphere During Geomagnetic Storms Driven by High-Speed Streams and Coronal Mass Ejections" and the algorithm to estimate the Joule heating is outlined in Section 2. Joule heating data files are only available for days with geomagnetic storms (including one day before the storm main phase begins and one day after the storm recovery phase ends) for the days where AMPERE, SuperMAG and SuperDARN data were available (1181 storm days between January 2010 and July 2023). For convenience, the data can be downloaded in two ways: a single bulk download containing all years at once (Jheat2010-2023.zip), or as individual yearly downloads (Jheat2010.zip, Jheat2011.zip, etc). The variables in the daily data files are listed in the table below. N_Time is the number of timesteps, N_MLat is the number of magnetic latitudes (MLat) and N_MLT is the number of magnetic local times (MLT) in the gridded data. Variable name Dimensions Units Content year (N_Time, 1) Year Year of measurement doy (N_Time, 1) Day of year Day of year (1-366 days) time (N_Time, 1) Fractional hour of day Start time of measurement in fractional hour (0 to 23.9667 hours) Jheat (N_MLat, N_MLT, N_Time) mW/m² Joule heating rates JheatInt (N_Time, 1) GW Total Joule heating in the Northern Hemisphere above 40° MLAT mlat (N_MLat, N_MLT) deg MLat for the Joule heating rates MLT (N_MLat, N_MLT) deg MLT for the Joule heating rates JheatQF (N_Time, 1) - Quality flags0 = Good data1 = Unreliable data bndryA (N_Time, 1) deg Equatorward boundary enclosing 80% of the AMPERE radial current densities (° MLat). Used in producing the quality flags bndrySD (N_Time, 1) deg Equatorward boundary of the SuperDARN convection region (° MLat). Used in producing the quality flags Time step 2 min (note: input AMPERE data is averaged over 10 min) Spatial grid 2° MLat / 1 hour of MLT, above 40° MLat Filler Values NaN File size 1.8 MB for each daily file File format NetCDF Metadata Date created and input filenames of the AMPERE and SuperMAG data used in the derivation of the Joule heating, used for version control File name [Date]_Joule_Heating_Gridded_[Version].ncdf For data inquiries contact Heikki Vanhamäki (heikki.vanhamä[e-mail]) or Marcus Pedersen ([e-mail]).