Variations in equatorial F2-layer parameters and comparison with IRI-2007 during a deep solar minimum

During the deep solar minimum between 23rd and 24th solar cycles, we study the variations in F2-layer peak electron density (NmF2), its height (hmF2), and the F2-layer thickness parameter (B0) at Jicamarca, and compare the observation with IRI-2007 predication. The observation results show that the hmF2, NmF2, and B0 are greater and smaller during daytime and nighttime, respectively. The sunrise peaks in hmF2 and B0 appear in all months. However, the post-sunset peaks do not occur in hmF2 and B0, except hmF2 in the equinox months. Seasonal variations show that the daytime hmF2 and NmF2 are greater in the equinox and summer months, while the daytime B0 are slightly greater in the equinox and winter months. For the comparison of observation with IRI-2007, the observed hmF2 is close to the predicted one during 19:00–23:00 LT. The NmF2 of URSI map and observation are close to each other during 00:00–13:00 LT, while the CCIR map modeled value generally agrees with the observed ones. Regarding the B0 comparison, the evident discrepancy between observation and Gulyaeva option is the locations of annual maxima. For the other option, the daily B0 peak is much broader in the IRI-B0-table option than observation. The CCIR map and Gulyaeva option produce a slightly better predication of NmF2 and B0, respectively. In contrast to the comparison results in preceding solar minimum, IRI-2007 provides a worse predication in the deep solar minimum.

► This study shows the variations in equatorial F2-layer during a deep solar minimum for the first time.
► The comparison of observation with IRI model during a deep solar minimum.
► The IRI predication is worse in the deep solar minimum than preceding solar minimum.