Laser Investigation of the Mesospheric Magnetic Field in the Auroral Zone
Abstract
By means of laser optical pumping and Larmor-resonance detection, it is possible to use the naturally occurring sodium layer in the mesosphere to measure Earth's scalar magnetic field at 90 km above ground. This is an altitude otherwise only accessible by rockets, which only will provide point measurements of very short time scales. During the winter of 2018-19 we have installed a cw sum-frequency laser for probing the sodium-atom Larmor resonance at the Artic Lidar Observatory for Mesospheric Research (ALOMAR) at Andøya in northern Norway, to measure and monitor the magnetic field in-situ in the high latitude mesosphere over longer time scales. The technique, which has been proved earlier at mid-latitudes, will in our project be applied to high latitudes in the auroral zone. This opens for a completely new domain of measurements of externally generated geomagnetic variations related to currents in the magnetosphere-ionosphere system. Here we report on the instrumental setup and present initial measurements of the mesospheric magnetic field. Furthermore, we discuss future improvements and plans.
- Publication:
-
EGU General Assembly Conference Abstracts
- Pub Date:
- April 2019
- Bibcode:
- 2019EGUGA..21.4905J