Air temperature lapse rates vary geographically and temporally. Sub-Antarctic Macquarie Island provides an opportunity to compare lapse rates between windward and leeward slopes in a hyper-oceanic climate. Lapse rates were steep by global standards, typically close to the dry adiabatic lapse rate despite the near-constant high humidity. Limited diurnal and seasonal variation occurs in lapse rates on Macquarie Island. High variability of lapse rates on the eastern (lee) slope in summer months and in the midday hours appears to be driven by solar radiation. No diurnal or seasonal pattern was evident on the western slope. Development of orographic cloud is expected to modify lapse rates, given the theoretical shift between dry and saturated adiabatic lapse rates that occurs with condensation of water vapour. Cloud cover was frequent, with higher elevations being under cloud 50% of the time, with no seasonal variation. However, cloud base level did not explain variation in lapse rates. Low cloud is likely to be of ecological importance because it influences fog precipitation, solar radiation and evapotranspiration. Year-round dominance of westerly airflows and limited seasonal variation in air temperature and humidity explain the limited seasonal variation in cloud cover and lapse rates on Macquarie Island.

中文翻译：

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超海洋气候中的气温递减率和云量

气温下降率因地域和时间而异。亚南极麦格理岛提供了一个机会来比较超海洋气候中迎风坡和背风坡之间的递减率。按照全球标准，失效率很高，尽管湿度几乎恒定，但通常接近干绝热失效率。麦格理岛的递减率存在有限的昼夜和季节性变化。在夏季月份和中午时间，东部（背风）斜坡上的高变化率似乎是由太阳辐射驱动的。西坡没有明显的昼夜或季节性模式。考虑到随着水蒸气的凝结而发生的干绝热递减率和饱和绝热递减率之间的理论转变，预计地形云的发展会改变递减率。云层频繁，海拔较高的地区有 50% 的时间处于云层之下，没有季节性变化。然而，云底水平并不能解释失效率的变化。低云可能具有生态重要性，因为它会影响雾降水、太阳辐射和蒸散。西风气流的全年主导地位和气温和湿度的有限季节性变化解释了麦格理岛云量和递减率的有限季节性变化。