Swarm equatorial electric field (EEF) L2 product, an introduction

Transcription

1 Swarm equatorial electric field (EEF) L2 product, an introduction British Geological Survey (BGS) National Space Institute DTU Space (DTU) Delft Institute of Earth Observation and Space Systems (DUT) Helmholtz Centre Potsdam - German Research Centre for Geosciences (GFZ) Eidgenössische Technische Hochschule Zürich (ETH) Institut de Physique du Globe de Paris (IPGP) The Swedish Institute of Space Physics (IRF) Laboratoire d'électronique des technologies de l'information (Leti) University of Calgary (UoC) Aerospace Research And Test Establishment (VZLU) with additional contributions from NASA Goddard Space Flight Center (GSFC) University of Colorado (CIRES) Charles University Prague (CUP) Doc. no: SW- TN- IPGP- GS- 0002, Rev: 1 da, Institut de Physique du Globe de Paris, France, Proprietary and intellectual rights of Institut de Physique du Globe de Paris, France are involved in the subject- matter of this material and all manufacturing, reproduction, use, disclosure, and sales rights pertaining to such subject- matter are expressly reserved. This material is submitted for a specific purpose as agreed in writing, and the recipient by accepting this material agrees that this material will not be used, copied, or reproduced in whole or in part nor its contents (or any part thereof) revealed in any manner or to any third party, except own staff, to meet the purpose for which it was submitted and subject to the terms of the written agreement. This document is released for use only if signed by the Project Manager or the Team Leader. Page 1 of 5

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3 Swarm equatorial electric field (EEF) L2 product, an introduction Doc. no: SW- TN- IPGP- GS- 0002, Rev: 1 da Page 3 of 5 Record of Changes Reason Description Rev Date Initial vers. Released 1 da The use and/or disclosure, etc. of the contents of this document (or any part thereof) is subject to the restrictions referenced on the front page.

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5 Swarm equatorial electric field (EEF) L2 product, an introduction Doc. no: SW- TN- IPGP- GS- 0002, Rev: 1 da Page 5 of 5 The day- time eastward equatorial electric field (EEF) in the ionospheric E- region plays a crucial role in equa- torial ionospheric dynamics. It is responsible for driving the equatorial electrojet (EEJ) current system, equatorial vertical ion drifts, and the equatorial ionization anomaly (EIA). Due to its importance, there is much interest in accurately measuring and modeling the EEF for both climatological and near real- time studies. The Swarm satellites make it possible to derive estimates of this equatorial electric field from measure- ments of the geomagnetic field. Indeed, due to the near- polar orbits of each satellite, the on- board magne- tometers record a full profile in latitude of the ionospheric current signatures at satellite altitude. These latitudinal magnetic profiles can be modeled using a first principles approach with empirical climatological inputs specifying the state of the ionosphere. Since the EEF is the primary driver of the low- latitude iono- spheric current system, the observed magnetic measurements can then be inverted for the EEF. The determination of the EEF using this principle has been implemented as a chain to routinely provide such estimates as Swarm Level 2 products Details of the algorithm for recovering the EEF from Swarm geomagnetic field measurements are provided in [AD- 1]. Applicable Documents [AD- 1] Alken, P., Maus, S., Vigneron, P., Sirol, O., Hulot, G., Swarm SCARF Equatorial Electric Field Inver- sion Chain, Earth Planets Space, 65, , 2013, doi: /eps The use and/or disclosure, etc. of the contents of this document (or any part thereof) is subject to the restrictions referenced on the front page.