An understanding of the current state of the Martian North Polar Residual Cap (NPRC) is needed to understand the North Polar Layered Deposits (NPLD) as a whole and the recent climate history of Mars. We investigate the evolution of small‐scale (∼10s of m) surface topography on the NPRC using an insolation‐driven ice accumulation/ablation model. We apply a coupled thermal and atmospheric model that calculates ice fluxes at each point on a model surface, allowing the topography to evolve through time. Our thermal model is validated using NPRC surface temperature data gathered by the Mars Climate Sounder (MCS) onboard the Mars Reconnaissance Orbiter (MRO). Roughness developed on the model surface is comparable to that of the NPRC, as we demonstrate using two examples of NPRC surface texture observed using the High‐Resolution Imaging Science Experiment (HiRISE) onboard MRO. We find that insolation‐driven accumulation and/or ablation yields surface roughness with characteristic spatial wavelengths ∼10 − 50 m—comparable to those observed on the NPRC—over timescales of 1–10 ka. The dominant topographic wavelength of a model surface increases as the surface evolves, implying that the wavelengths of topographic features observed on the NPRC may be indicative of the surface ages of those regions.

中文翻译：

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表面粗糙度的演变及其对火星北极残留帽年龄的影响

需要了解火星北极残留盖（NPRC）的当前状态，以了解整个北极分层沉积（NPLD）以及火星的近期气候史。我们使用日射驱动的积冰/消融模型研究了NPRC上小规模（约10s m）表面形貌的演变。我们应用耦合的热和大气模型，该模型计算模型表面上每个点的冰通量，从而使地形随时间变化。我们的热模型已使用火星侦察轨道飞行器（MRO）上的火星气候探测仪（MCS）收集的NPRC表面温度数据进行了验证。模型表面产生的粗糙度可与NPRC媲美，正如我们使用MRO机载高分辨率成像科学实验（HiRISE）观察到的两个NPRC表面纹理示例所展示的那样。我们发现，在1–10 ka的时间尺度上，日射驱动的累积和/或烧蚀产生的表面粗糙度具有特征性的空间波长〜10-50 m（与在NPRC上观察到的波长相比）。模型表面的主要地形波长随着表面的发展而增加，这意味着在NPRC上观察到的地形特征的波长可能表示这些区域的表面年龄。