SGER:Humidity and Ice Supersaturation Observations at South Pole Station

冰成核和冰云形成的确切机制的几个方面仍然没有解决，尽管，例如，卷云的属性被认为是一个很大的不确定性，在大气的辐射平衡。 在气候模式中准确地描述这些系统的微观物理特性对于模拟其辐射强迫以及确定对流层上层的人为粒子是否会影响冰云特性至关重要。卷云微观物理学的现场研究通常只能由限于中纬度或热带地区的相对较高高度的飞机进行。这就限制了观测时间和仪器有效载荷。 飞机测量还可能受到仪器表面的高撞击速度和加热速率的额外复杂性的影响，导致环境温度和湿度读数的不确定性。这项探索性研究（SGER）的小额赠款支持PI及时利用以前资助的，尚未执行的实地活动的机会，调查新湿度传感器的使用，以便更好地了解在独特的可访问环境中的冰成核和冰晶生长，即高海拔南极大气层。该提案符合SGER标准，即具有风险因素（即，不确定或不可预见的工程问题），但潜在的高回报（即，独特的数据集允许在难以进入的环境系统中跟踪冰晶的时间变化）。 该提案符合一个额外的SGER标准，代表一个独特的，预先存在的现场活动measurementopportunity.Broader影响的快速反应：预期的数据集，沿着与辅助数据收集的父项目（ESTA-0337876）的应用将有助于更好地了解冰微物理，卷云辐射强迫，并提高气候模拟工作的保真度。

Several aspects of the exact mechanisms of ice nucleation and ice cloud formation remain unsettled despite, for example, the properties of cirrus clouds being recognized as a large uncertainty in the radiative balance of the atmosphere. Accurate representation of the microphysics of these systems in climate models is crucial to simulation of their radiative forcing, and also to determining whether anthropogenic particles in the upper troposphere may be affecting ice cloud properties. In situ studies of the microphysics of cirrus clouds are normally accessible only by relatively high altitude aircraft restricted to the mid-latitudes, or the tropics. This poses limits on observation time and instrumentation payloads. Aircraft measurements may also be subject to additional complications of high impaction velocities and heating rates on instrument surfaces leading to uncertainties in ambient temperature and humidity readings. This Small Grant for Exploratory Research (SGER) supports the PI to take a timely opportunity of a previously funded, not yet executed field campaign, to investigate the use of a new humidity sensor in order to better understand the ice nucleation and ice crystal growth at a uniquely accessible environment, namely the high altitude South Pole atmosphere.The proposal meets the SGER criteria of having both an element of risk (i.e. uncertain or unforseen engineering issues) but a potentially high pay-off (i.e. a unique data set allowing temporal change of ice crystals to be followed in a difficult to access environmental system). The proposal meets an additional SGER criterion of representing a quick response to a unique, pre-existing field campaign measurement opportunity.Broader impacts: Applications of the expected data set, along with the ancillary data collected by the parent project (OPP-0337876) will contribute to better understanding of ice microphysics, radiative forcing of cirrus clouds, and improve the fidelity of climate modeling efforts.