Status: this preprint was under review for the journal ANGEO but the revision was not accepted.
The linear growth rate of Rayleigh–Taylor instability in ionospheric F layer
Kangkang Liu
Abstract. It is generally considered that the perturbation electric field generated by the charge accumulation caused by the current divergence is the driving force for Rayleigh–Taylor instability (RTI) in plasma. However, in previous calculation of the linear growth rate of RTI the current continuity equation was applied, which means the contribution of charge accumulation to the growth of RTI was ignored. Applying the perturbation electric field and the current continuity equation simultaneously in calculating the linear growth rate of RTI of the ionospheric F layer will give erroneous results. In this paper, we calculated the linear growth rate of RTI with the standard instability analysis method. The charge conservation equation was used in the calculation instead of the current continuity to study the contribution of charge accumulation to the growth of RTI. The results show that the contribution of charge accumulation to the linear growth rate of RTI is proportional to the ratio of Alfvén speed to the light speed. In ionospheric F layer the ratio is small, the contribution of charge accumulation to the growth of RTI is negligible. This indicates that the previous physical description of the RTI in the ionospheric F layer is wrong and a new physical description of RTI is needed. In the new physical description perturbation electric field and charge accumulation is not the cause, but the result of RTI. In ionospheric layer, background electric field and neutral wind velocity have no effect on the linear growth rate of RTI.
Received: 25 Feb 2019 – Discussion started: 06 Mar 2019
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When studying the Rayleigh-Taylor instability (RTI) in the ionosphere, I found that the physical description of RTI in ionosphere attribute the growth of RTI to charge accumulation, however, the current continuity equation was used during the calculation of the linear growth rate. Also, the linear growth rate widely used tends to infinity when the collision frequency tends to zero. In this paper, we derived the linear growth rate of RTI and rectified the physical description of the RTI process.
When studying the Rayleigh-Taylor instability (RTI) in the ionosphere, I found that the physical...
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