We study horizontal ice plates in clouds using satellite lidar measurements of the Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). This study investigates global microphysical and geographical properties of horizontal ice plates to obtain insights into ice‐plate climatology based on lidar’s long‐term measurements during 2006–2014. We then summarize the effects of the lidar's viewing angle change from 0.3° to 3.0° in 2007 on satellite particle phase/shape classifications. Using a classification algorithm developed in the previous studies, we show that the ice plate detection decreases by 81.7% due the tilting. With an updated version of this algorithm, 30.8% of these are recovered, although 50.8% remain undetected. Nevertheless, this study also shows that geographical characteristics of ice plates are still preserved during the off‐nadir period (within the remaining 50%), suggesting the undiscovered climatological information on ice plates in the post‐2007 observations. According to our analysis, the tilting mainly affects horizontal ice plate detection, while the impacts on water and randomly oriented ice detections are limited. The temperature of the ice plates ranges from −25.5°C and −7.5°C, with a mode temperature of −13.5°C, although the ice plates also occur ubiquitously across mid‐ to high‐latitudes between −20°C and −40°C, which is much colder than what found in previous nadir studies. This study offers a detailed discussion on the fundamental characteristics of horizontal ice plates that will provide robust information for the algorithm preparation for future satellite lidar observations such as the Earth, Clouds, Aerosol and Radiation Explorer (EarthCARE).

中文翻译：

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云层中水平冰盖的气候学观点：天底和离天底CALIPSO观测结果

我们使用Cloud-Aerosol Lidar和红外Pathfinder卫星观测（CALIPSO）的卫星激光雷达测量研究了云中的水平冰盖。这项研究调查了水平冰盖的全球微物理和地理特性，以基于2006-2014年激光雷达的长期测量获得对冰盖气候学的见识。然后，我们总结了2007年激光雷达的视角从0.3°变为3.0°对卫星粒子相位/形状分类的影响。使用先前研究中开发的分类算法，我们显示由于倾斜，冰盖检测减少了81.7％。使用此算法的更新版本，可以恢复其中的30.8％，尽管仍未检测到50.8％。尽管如此，这项研究还表明，在离最低点的时期（剩余的50％以内），冰盖的地理特征仍然得以保留，这表明2007年以后的观测中尚未发现冰盖的气候学信息。根据我们的分析，倾斜主要影响水平冰板的探测，而对水和随机定向冰的探测的影响是有限的。冰盖的温度范围为-25.5°C至-7.5°C，模式温度为-13.5°C，尽管冰盖也普遍出现在−20°C至−40的中高纬度范围内°C，比以前的最低温度研究低得多。