The lunar polar regions offer permanently shadowed regions (PSRs) representing the only regions which are cold enough for water ice to accumulate on the surface. The Lunar Exploration Neutron Detector (LEND) aboard the Lunar Reconnaissance Orbiter (LRO) has mapped the polar regions for their hydrogen abundance which possibly resides there in the form of water ice. Neutron suppression regions (NSRs) are regions of excessive hydrogen concentrations and were previously identified using LEND data. At each pole, we applied thermal modeling to three NSRs and one unclassified region to evaluate the correlation between hydrogen concentrations and temperatures. Our thermal model delivers temperature estimates for the surface and for 29 layers in the sub-surface down to 2 m depth. We compared our temperature maps at each layer to LEND neutron suppression maps to reveal the range of depths at which both maps correlate best. As anticipated, we find the three south polar NSRs which are coincident with PSRs in agreement with respective (near)-surface temperatures that support the accumulation of water ice. Water ice is suspected to be present in the upper ≈19 cm layer of regolith. The three north polar NSRs however lie in non-PSR areas and are counter-intuitive as such that most surfaces reach temperatures that are too high for water ice to exist. However, we find that temperatures are cold enough in the shallow sub-surface and suggest water ice to be present at depths down to ≈35–65 cm. Additionally we find ideal conditions for ice pumping into the sub-surface at the north polar NSRs. The reported depths are observable by LEND and can, at least in part, explain the existence and shape of the observed hydrogen signal. Although we can substantiate the anticipated correlation between hydrogen abundance and temperature the converse argument cannot be made.

中文翻译：

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LEND预测的月球两极附近温度及其与氢的相关性

月球极地地区提供永久阴影区 (PSR)，代表唯一冷到足以让水冰在地表积聚的地区。月球勘测轨道飞行器 (LRO) 上的月球探索中子探测器 (LEND) 已经绘制了极地地区的氢丰度图，这些氢丰度可能以水冰的形式存在于那里。中子抑制区 (NSR) 是氢浓度过高的区域，之前使用 LEND 数据进行了识别。在每个极点，我们将热模型应用于三个 NSR 和一个未分类区域，以评估氢浓度与温度之间的相关性。我们的热模型提供地表和地下至 2 m 深的 29 层的温度估计值。我们将每一层的温度图与 LEND 中子抑制图进行了比较，以揭示两个图最相关的深度范围。正如预期的那样，我们发现与 PSR 重合的三个南极 NSR 与支持水冰积累的各自（近）地表温度一致。水冰被怀疑存在于风化层的上部约 19 厘米层中。然而，三个北极 NSR 位于非 PSR 区域并且违反直觉，因此大多数表面达到的温度对于水冰来说太高而无法存在。然而，我们发现浅层地下的温度足够低，并表明水冰存在于约 35-65 厘米的深度。此外，我们找到了将冰泵入北极 NSR 地下的理想条件。LEND 可以观测到报告的深度，并且至少可以部分解释观测到的氢信号的存在和形状。虽然我们可以证实氢丰度和温度之间的预期相关性，但不能提出相反的论点。