Low latitude monthly total electron content composite correlations

Spatial correlations of total electron content (TEC) variability are compared among two SAMI3 model runs and Jet Propulsion Laboratory Global Ionospheric Maps (JPL/GIM). Individual monthly correlation maps constructed with Equatorial reference points at 12 evenly spaced longitudes universal times. TEC composite (TCCs) then calculated by averaging the individual maps, shifted zonally to synchronize local time. The TCC structures quantified using Gaussian fits in zonal meridional directions. A non-zero large-scale “base correlation” is found all three datasets for 2014, a year high solar activity. Higher base generally occur than JPL/GIM. run driven climatological neutral fields shows higher neutrals from Whole Atmosphere Community Climate Model ionosphere extension (WACCM-X) simulation. Base values strongly correlate F10.7 standard deviations. Empirical Orthogonal Function (EOF) analyses confirm usually, although not always, related forcing. Strong between Ap index EOF modes also observed, consistent geomagnetic forcing field. width examined, these vary considerably time, month, dataset. Off-Equator conjugate point each dataset variations month time analyzed. Analysis TCCs 2010, low activity, that as well first mode weaker 2014.