compared to previous models, which used fewer intervals and less detailed representations of energy loss [ 5 ], [ 2 ].
Our model is designed to analyze the ionization contributions from different types of cosmic rays( CRs) in the ionosphere and middle atmosphere. These types include Galactic Cosmic Rays( GCRs), Solar Cosmic Rays( SCRs), and Anomalous Cosmic Rays( ACRs). Each sub-model within our framework is tailored to evaluate the specific ionization contributions of these CR types, taking into account their distinct energy characteristics across the atmosphere.
To accurately assess the impact of differential energy spectra on ionization processes in the middle atmosphere, we rely on satellite measurements of cosmic ray spectra. In this study, we place particular emphasis on ACR spectra. By decomposing the ACR spectra into various groups based on the nuclei type and corresponding energy intervals, we can analyze their properties and understand how they influence ionization losses at different atmospheric boundaries.
Our newly developed model, CORSIMA( COsmic Ray Spectra and Intensity in the Middle Atmosphere), builds upon advancements made in our previous model, CORIMIA( COsmic Ray Ionization Model for Ionosphere and Atmosphere) [ 16 ]. CORSIMA refines the analysis by introducing more detailed energy intervals, which allows us to capture the contributions of ACRs more accurately across different atmospheric layers. This improvement helps us provide a comprehensive understanding of how ACR spectra contribute to ionization in the middle atmosphere, especially in the context of space weather interactions.
By leveraging the capabilities of CORSIMA and refining the treatment of energy intervals, we aim to enhance the precision of ionization models and offer new insights into the behavior of cosmic rays in the Earth ' s atmosphere.
3. MODEL DESCRIPTION FOR ACRS
The submodel for calculating the ionization rate profiles of Anomalous Cosmic Rays( ACRs) differs significantly from the submodels used for Galactic Cosmic Rays( GCRs) and Solar Cosmic Rays( SCRs). One of the key differences is that ACR constituents are multiply charged, unlike most GCRs and SCRs. This requires the introduction of a charge decrease interval to account for the effects of multiple ionizations as ACRs travel through the atmosphere [ 16 ], 1 ]. Additionally, the atomic weight A of the particles is taken into consideration, as it plays a significant role in the ionization process.
When analyzing the penetration of ACRs into the atmosphere, we focus on the electron production rate within three energy intervals. These intervals pertain to the low-energy range of ionization losses, measured in MeV. g− ¹. cm ², and follow the Bohr-Bethe-Bloch formula. This formula allows us to calculate the energy loss per unit of path length based on the particle ' s charge and energy.
Unlike single-ionized particles, which have a more straightforward ionization loss function, multiply charged ACRs introduce new dependencies across the energy intervals. As a result, the ionization loss function for ACRs becomes more complex and generalized compared to the case where the charge Z = 1. This refinement provides a more accurate representation of how ACRs interact with the atmosphere, particularly in the low-energy regime where ionization losses are most significant.
By incorporating these adjustments into the model, we are able to better understand the impact of ACRs on atmospheric ionization and how they contribute to electron production at different altitudes.
2.57 � 10�E�. � if kT � E � 0.15 MeV / n, interval 1
( 3) � � �� � � �. �� 1540E if 0.15 �E�E
� �� � � 0.15Z � MeV / n, interval 2 �
231 �Z � E ��. �� if E � �E�200 MeV / n, interval 2
We will now present the interval values crucial for calculating cosmic ray( CR) spectra, intensities, and ionization rates in the middle atmosphere and lower ionosphere. All particle energies are given in units of MeV / nucleon. The lower energy bound is defined by the parameter kTkTkT, which reflects the thermal state of charged particles.
In the first two intervals, kT < E < 0.15 < Ea = 0.15Z2, the CR spectrum exhibits both descending and ascending phases. The particle intensities change their slope at approximately 0.15 MeV / nucleon, with interval 2 * representing the charge decrease interval due to electron capture during atmospheric penetration. These first two intervals also highlight the increase in ionization losses, as demonstrated by the ionization loss function in equation( 1).
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