Propagation properties of weakly nonlinear ion acoustic waves are investigated in a plasma at the Venusian ionosphere. The plasma model consists of two positive cold ions (oxygen O ⁺ and hydrogen H ⁺), as well as isothermal electrons. The basic set of fluid equations is reduced to Zakharov-Kuznetsov (ZK) equation and linear inhomogeneous ZK-type equation (LIZKT) equation. The renormalization method is adopted to obtain solitary solutions of both equations. The effects of plasma parameters and higher-order correction on the nature of the solitary waves are investigated. It is found that the wave phase velocity is supersonic, which is in agreement with the observations. Furthermore, the higher-order correction enlarges the soliton amplitude, which is suitable for describing the solitary waves when the wave amplitude grows.

在金星电离层的等离子体中研究了弱非线性离子声波的传播特性。等离子体模型包含两个正的冷离子（氧O ⁺和氢H ⁺）以及等温电子。流体方程的基本集合简化为Zakharov-Kuznetsov（ZK）方程和线性非均匀ZK型方程（LIZKT）方程。采用重归一化方法获得两个方程的孤立解。研究了等离子体参数和高阶校正对孤立波性质的影响。发现波相速度是超音速的，这与观测结果一致。此外，高次校正会增大孤子振幅，适合于在波幅增大时描述孤立波。