Prospects for meteotsunami detection in earth's atmosphere using GNSS observations

Abstract

We study, for the first time, the physical coupling and detectability of meteotsunamis in the earth's atmosphere. We study the June 13, 2013 event off the US East Coast using Global Navigation Satellite System (GNSS) radio occultation (RO) measurements, Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) temperatures, and ground-based GNSS ionospheric total electron content (TEC) observations. Hypothesizing that meteotsunamis also generate gravity waves (GWs), similar to tsunamigenic earthquakes, we use linear GW theory to trace their dynamic coupling in the atmosphere by comparing theory with observations. We find that RO data exhibit distinct stratospheric GW activity at near-field that is captured by SABER data in the mesosphere with increased vertical wavelength. Ground-based GNSS-TEC data also detect a far-field ionospheric response 9 h later, as expected by GW theory. We conclude that RO measurements could increase understanding of meteotsunamis and how they couple with the earth's atmosphere, augmenting ground-based GNSS TEC observations.

Keywords: Atmosphere; GNSS; Meteotsunami; Radio occultations; Total electron content.

Fig. 1

Geographic distribution of buoys (blue triangles), ground-based GNSS stations (green dots), and radio occultation (RO) soundings (magenta squares). Buoys marked in red asterisks and an 8-digit number are analyzed, and buoy #8,452,660 is collocated with an RO sounding

Fig. 2

Sea-level height and normalized spectrograms as a function of time from 16:00 UTC until 23:59 UTC on June 13, 2013 for the four buoy stations marked with red asterisks in Fig. 1

Fig. 3

Snapshot of the June 13, 2013, meteotsunami together with wind conditions and GW properties at 18:30 UTC at the US coastal region. a Meteotsunami wavefront produced by the RIFT model (see, https://www.youtube.com/watch?v=ykABRe5Yt3c). b, c Vertical profiles of the eastward and northward wind components from MERRA-2, and d the estimated intrinsic frequency and vertical wavelength of anticipated meteotsunami-generated GWs

Fig. 4

An example of the atmospheric response to the meteotsunami at 18:30 UTC captured by multiple space-based observing platforms together with the anticipated GW properties. a Observed vertical wavenumber spectra in the troposphere (solid black) and stratosphere (solid blue) and theoretical saturation lines (dashed). b Vertical temperature profiles from MERRA-2 (blue), AIRS v7 (red), ERA-Interim (green), COSMIC (black), and the background fit (dashed orange). c Zoom-in of vertical temperature profiles in the 14–30 km altitude range, d vertical temperature fluctuations, and e normalized wavelet power with respect to its variance of the temperature residuals in panel (d) between 15 and 40 km

Fig. 5

Signatures of meteotsunami-induced gravity waves (GWs) in the neutral atmosphere and ionosphere. We quantify their 3D properties as a function of time and altitude. a Estimated vertical group velocity from COSMIC (black) and TIMED/SABER observations (blue circles) with altitude. b Vertical temperature profile from TIMED/SABER (black) with the background fit (dashed orange), and c estimated vertical temperature fluctuations. d Time series of vertical TEC perturbations over station CTPU (black) with its precision level (purple rectangle), and e periodogram of the vertical TEC perturbations with time

Fig. 6

Time series of vertical TEC perturbations over GNSS stations CTPU, URIL, and CTEG tracking GPS satellites pseudorandom noise (PRN) 04 and 02. Purple rectangles mark the typical vertical TEC noise level and the dashed blue lines mark the start of the vertical TEC enhancement. (Bottom right) TerraSAR-X RO vertical temperature profile (black) and the background fit (orange) at 20:38 UTC

Fig. 7

Keograms of ionospheric vertical TEC perturbations as a function of time on June 14, 2013, from 01:00 UTC until 09:00 UTC and distance centered over the URIL station at a −90° and b 0° azimuths, respectively. Coherent ionospheric vertical TEC perturbations at 250 km as a function of distance and time over the URIL station at c −90° and d 0° azimuths, respectively