Место издания:COSPAR COSPAR Scientific Assembly Афины Fabys, Uhtwbz
Первая страница:C1.5-0000-22
Последняя страница:C1.5-0000-22
Номер статьи:30008
Аннотация:question arises as to what will happen to the atmosphere during the geomagnetic reversal,
when the dipole component weakens. For an answer, atmospheric erosion models were generalized
to the case of a dipolar-quadrupolar magnetosphere. The dependence of ion escape
rates on the configuration and strength of the geomagnetic field showed that, during reversal,
magnetic shielding still effectively protects the atmosphere from sputtering and pickup of ions,
but contributes to polar and auroral winds from polar caps and cusps. This conclusion is valid
for quiet periods of solar activity. However, the geomagnetic reversal duration covers several
thousand years, during which many extreme events occur, that require the model to take into
account changes in solar wind pressure and EUV radiation, as the source of ion production. In
addition to solar activity, these parameters also depend on the age of Sun, which is important
for paleomagnetic reversals. Paleodata indicate an increase in isotope ratios 18O and 15N with
an increase in the reversal rates during the Phanerozoic eon that, according to estimates of the
efficiency of isotope fractionation by each escape mechanism, may be due to the atmospheric
loss by solar wind-driven escape.
This work is supported by the grant MK-5053.2022.6 of the Ministry of Science and Higher
Education of the Russian Federation.