Abstract
Measurements from the Solar Occultation For Ice Experiment (SOFIE) are
used to characterize meteoric smoke and meteor influx in both
hemispheres. New smoke extinction retrievals from sunrise measurements
in the Northern Hemisphere (NH) are presented, which complement the
previously reported sunset observations in the Southern Hemisphere (SH).
The sunrise observations are in good agreement with simulations from the
Whole Atmosphere Community Climate Model (WACCM), for both the seasonal
and height dependence of smoke in the mesosphere. The SOFIE - WACCM
comparisons assumed that smoke in the mesosphere exists purely as
Fe-rich olivine. This is justified because olivine is detected optically
by SOFIE, it has the same elemental abundance as incoming meteoroids,
and it is anticipated by theory and laboratory experiments. Treating
mesospheric smoke as olivine furthermore brings closure in terms of the
ablated and total meteoric influx determined here from SOFIE and a
recent and independent investigation based on models and observations.
SOFIE observations from 2007 - 2021 indicate a global ablated meteoric
influx of 7.3 +/- 2.0 metric tons per day (t/d), which corresponds to a
total influx (ablated plus surviving material) of 25.0 +/- 7.0 t/d.
Finally, SOFIE indicates less smoke in the polar winter SH compared to
NH winter. Finally, the results indicate stronger descent in the NH
polar winter mesosphere than in the SH winter. This hemispheric
asymmetry is indicated by smoke and water vapor results from both SOFIE
and WACCM.