DLR-Logo -> http://www.dlr.de
DLR Portal Home | Imprint | Privacy Policy | Contact | Deutsch
Fontsize: [-] Text [+]

Spring-fall asymmetry in VLF amplitudes recorded in the North Atlantic region: The fall-effect

Macotela, E.L. and Clilverd, Mark and Renkwitz, Toralf and Chau, Jorge L. and Manninen, J. and Banyś (geb. Wenzel), Daniela (2021) Spring-fall asymmetry in VLF amplitudes recorded in the North Atlantic region: The fall-effect. Geophysical Research Letters, 48 (16), e2021GL094581. Wiley. doi: 10.1029/2021GL094581. ISSN 0094-8276.

[img] PDF - Published version


A spring-fall asymmetry is observed in daytime amplitude values of very low frequency (VLF) radio wave signals propagating over the North Atlantic during 2011-2019. We explore the processes behind this asymmetry by comparing against mesospheric mean temperatures and the semidiurnal solar tide (S2) in mesospheric winds. The solar radiation influence on VLF subionospheric propagation was removed from the daytime VLF amplitude values, isolating the fall-effect. Similarly, the symmetric background level was removed from mesospheric mean temperatures undertaking comparable analysis. During fall, all three analyzed parameters experience significant deviation from their background levels. The VLF amplitude variation during spring is explained by the seasonal variation in solar illumination conditions, while the fall-effect can be interpreted as a mean zonal wind reversal associated with both a S2 enhancement, and temperature reductions. Decreases in temperature can produce decreases in collision frequency, reducing VLF signal absorption, driving the observed VLF asymmetry.

Item URL in elib:https://elib.dlr.de/148776/
Document Type:Article
Title:Spring-fall asymmetry in VLF amplitudes recorded in the North Atlantic region: The fall-effect
AuthorsInstitution or Email of AuthorsAuthor's ORCID iDORCID Put Code
Macotela, E.L.UNSPECIFIEDhttps://orcid.org/0000-0003-3076-1946UNSPECIFIED
Clilverd, MarkBritish Antarctic Survey, High Cross, Cambridge, UKhttps://orcid.org/0000-0002-7388-1529UNSPECIFIED
Renkwitz, ToralfLeibnitz Inst. Univ. Rostock, Kühlungsborn, Germanyhttps://orcid.org/0000-0002-0739-2655UNSPECIFIED
Chau, Jorge L.Leibniz Institute of Atmospheric Physics, Kühlungsborn, Germanyhttps://orcid.org/0000-0002-2364-8892UNSPECIFIED
Manninen, J.University of Ouluhttps://orcid.org/0000-0003-2866-4231UNSPECIFIED
Banyś (geb. Wenzel), DanielaUNSPECIFIEDhttps://orcid.org/0000-0001-6623-6612UNSPECIFIED
Date:30 July 2021
Journal or Publication Title:Geophysical Research Letters
Refereed publication:Yes
Open Access:Yes
Gold Open Access:No
In ISI Web of Science:Yes
Page Range:e2021GL094581
Keywords:VLF propagation, very low frequencies, ionosphere, D-region, mesosphere, fall-effect, october effect
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Space
HGF - Program Themes:Communication, Navigation, Quantum Technology
DLR - Research area:Raumfahrt
DLR - Program:R KNQ - Communication, Navigation, Quantum Technology
DLR - Research theme (Project):R - Ionosphere
Location: Neustrelitz
Institutes and Institutions:Institute for Solar-Terrestrial Physics
Deposited By: Banyś (geb. Wenzel), Daniela
Deposited On:14 Oct 2022 12:07
Last Modified:28 Jun 2023 13:33

Repository Staff Only: item control page

Help & Contact
electronic library is running on EPrints 3.3.12
Website and database design: Copyright © German Aerospace Center (DLR). All rights reserved.