Ionospheric respons to gravity waves induced by tropospheric deep convection in mid-latitudes

Our case study investigates coincidental occurrence of intense tropospheric convection and upper atmospheric variability, focusing on gravity wave (GW) generation in the tropospheric height and its possible effects on the ionospheric layers E, sporadic E (Es), and F2. Our analysis presents: several extreme convective storm events that occurred over Central Europe under tropical air mass conditions, not directly linked to the passage of a cold front. Two primary classifications of convective systems are considered: (1) rapidly propagating supercells characterized by strong, rotating updrafts; and (2) long-lived linear mesoscale convective systems (MSCs) connected to derecho. The latter are distinguished by their broad horizontal extent, long lifetimes of several hours and storm trajectories exceeding 400 km. Based on satellites data, meteorological radar data, and ionospheric radar and Doppler sounding techniques, we investigate ability of such types of severe weather events acting as an effective sources of gravity waves capable of propagating into the middle and eventually reaching the upper atmosphere. We focus on effects of GW within the stratosphere and ionosphere in E, Es, and F2 regions. Results contribute and enlarge our investigation of connection between the intense activity of the lower atmosphere and the dynamics of the upper atmosphere in mid-latitudes.

Our previous studies identified simultaneous (a few hour delay) effects in the ionospheric parametrs from the lower ionosphere up to peak of F2 layer. Our study indicates differences in the ionospheric response according to the GW source. In particular, we focus on sporadic E characteristics, its occurrence and blanketing ability. Es layer formation in midlatitude, during low geomagnetic conditions and stable solar forcing, is dependent on neutral atmosphere motion, hence is influenced by GW propagation or depositing their momentum. Sporadic E layers in well pronounced summer phenomenon, while the tropospheric convective events appeared to intensify according to recent climatic studies.

This research was supported by the Johannes Amos Comenius Programme (P JAC), project No. CZ.02.01.01/00/22_008/0004605, Natural and anthropogenic georisks, by the GA ČR GA25-14158L, and also by the ESA project HORIZON 2020, PITHIA-NRF 101007599.