3D Simulation Data for: Localized Convection in Sputnik Planitia, Pluto

Numerical simulations of bottom-heated convection in a layer of nitrogen ice under temperature conditions expected on Sputnik Planitia, Pluto. Numerical calculations are performed in a 12x12x1 box, where the top and bottom boundaries are maintained at constant temperatures of 36 K and 63 K, respectively. The top boundary is free-slip, whereas the bottom boundary is no-slip. The vertical boundaries are free-slip and thermally insulated. The viscosity follows the power-law creep function, i.e., it depends on both temperature and stress, and the experimentally determined flow-law parameters for power-law creep in nitrogen ice are used (Yamashita et al., 2010). The calculations are conducted using CitcomCU (Moresi and Gurnis, 1996; Zhong, 2006). The numerical domain is divided into cube-shaped finite elements, and the number of elements in the vertical direction is 32. For a 12x12x1 box, this resolution translates into 4,718,592 finite elements. The stability boundaries of the localized convection planform are determined using the approach described in previous studies (e.g., Solomatov, 2024). Localized plume is found to be stable between the Rayleigh numbers Ra = 770 and Ra = 840. The outputs of our simulations at Ra = 770 and Ra = 840 are provided. For each case, the nondimensional values of the temperature at the transverse cross-section through the center of the plume (i.e., transverse slice at y = 6) and the nondimensional values of the surface observables- the topographic anomaly, surface heat flux, and absolute surface convective velocity - along this cross-section are given. The procedure to dimensionalize the quantities is also described, which can help reproduce Fig. 3 in the paper.针对冥王星史普尼克平原（Sputnik Planitia）预期的温度条件下，氮冰层内底部加热对流的数值模拟研究。数值计算在12×12×1的计算域内开展，其上下边界分别维持在36 K与63 K的恒定温度。上边界采用自由滑移（free-slip）边界条件，下边界则为无滑移（no-slip）边界条件；垂直边界同时满足自由滑移与绝热条件。流体黏度遵循幂律蠕变（power-law creep）函数形式，即同时依赖于温度与应力；计算中采用了由实验测定的氮冰幂律蠕变流动定律参数（Yamashita等，2010）。本计算采用CitcomCU数值程序完成（Moresi与Gurnis，1996；Zhong，2006）。数值计算域被离散为立方体形有限单元，垂向单元数量为32。针对12×12×1的计算域，该离散分辨率对应的总单元数为4718592个。局地对流流型的稳定边界采用前人研究中的方法确定（例如Solomatov，2024）。研究发现，局地羽流在瑞利数（Rayleigh number，Ra）770至840区间内保持稳定。本数据集提供了Ra=770与Ra=840两组模拟工况的输出结果。针对每组工况，均给出了穿过羽流中心的横向截面（即y=6处的横向切片）上的无量纲温度分布，以及该截面上的地表可观测物理量——地形异常、表面热流与表面绝对对流速度——的无量纲数值。同时还给出了各物理量的无量纲化转换方法，可用于复现论文中的图3。