In this paper, we present near‐simultaneous observations of a gravity wave (GW) event in the stratosphere, mesosphere, and ionosphere over the South Central United States and track it from its convective source region in the troposphere to the ionosphere, where it appears as a traveling ionospheric disturbance (TID). On 4 April 2014 concentric GW ring patterns were seen at stratospheric heights in close proximity to a convective storm over North Texas in the Atmospheric Infrared Sounder data on board the NASA Aqua satellite. Concentric GWs of similar orientation and epicenter were also observed in mesospheric nightglow measurements of the Day/Night Band of the Visible/Infrared Imaging Radiometer Suite on the Suomi National Polar‐orbiting Partnership satellite. Concentric TIDs were seen in total electron content data derived from ground‐based GPS receivers distributed throughout the U.S. These new multisensor observations of TIDs and atmospheric GWs can provide a unique perspective on ionosphere‐atmosphere coupling.

The 11 March 2011 Tohoku earthquake generated a massive tsunami off the Pacific coast of Japan, which launched intense atmospheric gravity waves (AGWs) in the atmosphere. Within the context of this study, the Tohoku tsunami event was unique in the sense that it enabled a rare, controlled experiment for investigating how AGWs are launched, propagate, and dissipate in relation to tsunamis. This tsunami was a long‐lived, rapidly traveling source of a rich spectra of AGWs excited just above the ocean‐atmosphere interface. In this paper we use GPS total electron content (TEC) data from the United States (U.S.) to look for these AGWs in the ionosphere via their signatures as traveling ionospheric disturbances (TIDs). We find a spectrum of TIDs in the TEC data propagating in the direction of the tsunami that last for several hours over the West Coast of the U.S. and as far inland as western Colorado. The observed TIDs have periods that range from 14 to 30 min, horizontal wavelengths that range from 150 and 400 km, and horizontal phase speeds that range from 180 to 260 m/s. We use reverse ray tracing to show that the Tohoku tsunami was likely the source of these TIDs. Using the networks of GPS receivers in the U.S., we map the tsunami‐launched TIDs over the western U.S. and investigate the spectrum of gravity waves enabling an enhanced understanding/verification of the properties of AGWs as a function of the launch angle.

We examine the total electron content (TEC) from GPS receivers over the United States on March 25–26, 2015. We observe partial to nearly fully concentric rings of traveling ionospheric disturbances (TIDs) with centers close to deep convection. Many of these TIDs have observed horizontal phase speeds cH > 300 m/s, suggesting they are induced by gravity waves (GWs) created in the thermosphere. We investigate the largest‐amplitude concentric TIDs at 23:00 UT on March 25 and 01:20 UT on March 26. We find that cH and the GW period τr increase linearly with radius and the horizontal wavelength, λH, increases quadratically with radius. This is expected if the GWs are excited by point sources. For these GWs, cH = 150–530 m/s, τr ∼ 8–40 min, and λH ∼ 100–500 km. Using reverse ray‐tracing, no GW with cH > 200 m/s propagates below z = 100 km, 73% of the GWs in the first case cannot propagate below z ∼ 100 km, all of the GWs in the second case cannot propagate below z ∼ 100 km, and the inferred thermospheric point sources are ∼2–4° from deep convection. Because the underlying GWs are most likely excited by a point source and most must be created in the thermosphere, we find that these concentric TIDs are most likely induced by GWs generated in the thermosphere, including those with cH = 150–200 m/s. Their close proximity to deep convection and the TEC map asymmetries suggest these TIDs are likely induced by secondary GWs from local horizontal body forces created by the dissipation of primary GWs from deep convection.

[1] The evolution of the pre-reversal enhancement in the vertical ion drift in the equatorial F region is described via an examination of the current systems determined from a coupled ionosphere thermosphere model. We find that the pre-reversal enhancement is produced by a reversal in the F region zonal wind that results in an additional upward current where the E region Pedersen conductivity is declining across the dusk sector. The continuity of the total current is maintained through an enhancement in the eastward zonal current and an associated upward drift of the ions.Citation: Heelis, R. A., G. Crowley, F. Rodrigues, A. Reynolds, R. Wilder, I. Azeem, and A. Maute (2012), The role of zonal winds in the production of a pre-reversal enhancement in the vertical ion drift in the low latitude ionosphere,

During 30 September to 9 October 2016, Hurricane Matthew traversed the Caribbean Sea to the east coast of the United States. During its period of greatest intensity, in the central Caribbean, Matthew excited a large number of concentric gravity waves (GWs or CGWs). In this paper, we report on hurricane‐generated CGWs observed in both the stratosphere and mesosphere from spaceborne satellites and in the ionosphere by ground Global Positioning System receivers. We found CGWs with horizontal wavelengths of ~200–300 km in the stratosphere (height of ~30–40 km) and in the airglow layer of the mesopause (height of ~85–90 km), and we found concentric traveling ionospheric disturbances (TIDs or CTIDs) with horizontal wavelengths of ~250–350 km in the ionosphere (height of ~100–400 km). The observed TIDs lasted for more than several hours on 1, 2, and 7 October 2016. We also briefly discuss the vertical and horizontal propagation of the Hurricane Matthew‐induced GWs and TIDs. This study shows that Hurricane Matthew induced significant dynamical coupling between the troposphere and the entire middle and upper atmosphere via GWs. It is the first comprehensive satellite analysis of gravity wave propagation generated by hurricane event from the troposphere through the stratosphere and mesosphere into the ionosphere.