Studying Ice and Mixed Phase clouds using Laboratory EXperiments - SIMPLEX

使用实验室实验研究冰和混合相云 - SIMPLEX

• 批准号: NE/G000875/1
• 负责人: Paul Connolly
• 金额: $ 11.37万
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FG000875%2F1
• 关键词: Studying; Ice; Mixed; Phase; clouds

At any one time cloud coverage over the earth is around 70% on average and to some extent they may warm or cool the planet. I think everybody in the UK is familiar with clouds blocking the suns light and making it cooler, thick liquid clouds generally do this by reflecting the suns radiation back to space. However, ice clouds that are high up within the atmosphere may actually cause a warming effect at the surface by trapping and emitting thermal radiation. The relative amount of cooling vs heating ice dependent on the number and size of ice particles within high clouds. Our current measurements in the true atmosphere have failed to quantify the radiative properties of these clouds due to current instrumental difficulties in measuring small ice particles from aircraft. Precipitation is also an important factor in climate change and one that ice particles play a huge role in. As early as 1789 Benjamin Franklin suggested that `much of what is rain, when it arrives at the surface of the earth might have been snow when it began its descent...'. And this is very true, current estimates place the ice phase responsible for the majority of precipitation in the tropics (60%). In the part of the earths atmosphere in which we live, temperature decreases significantly with height. Furthermore, one must also consider the annual damage to crop caused by hail storms. It is a wide misconception that ice particles form when the temperature is colder than 0C. The current theories show that this only happens when liquid water has enough impurities. So for example when the water touches a dirty surface like the ground or even a car window - even if your windows are clean they still contain enough impurities to form ice crystals - the water can freeze. However, in the atmosphere water droplets are in a very pure state, and most of them do not freeze until the temperature is as cold as -35C. But there are some impurities albeit few in the atmosphere, and if these particles are contained within the cloud, then ice particles will form at temperatures perhaps as warm as -5C. The problem is that the number of these impurities alone can not explain the number of ice particles that are observed within the cloud. There are several theories that have been put forward to explain this and some have good experimental evidence for them. However, in order to accurately assess climate change we need to quantitatively determine their importance. This work will seek to resolve the three aforementioned problems by gaining an understanding of effiency of snow formation under simulated laboratory conditions and perform experiments looking at the physics of ice particle formation. Scientists at the University of Manchester, School of Earth, Atmospheric and Environmental Sciences will produce realistic clouds in a so called ice-fall chamber. They will simulate the physics of natural cloud formation itself and use state-of-the-science instrumentation to probe the particles within the cloud. By understanding the fundamental physics, they will be able to work with the met office and other universities to better understand the problem of climate change. The Manchester scientists also seek to collaborate with leading scientists from Hertfordshire university, Germany and the US in order to make progress in this area.

在任何时候，云覆盖地球的平均面积都在70%左右，在某种程度上，它们可能会使地球变暖或变冷。我想英国的每个人都很熟悉云层阻挡太阳的光线，使它变冷，厚厚的液态云通常通过将太阳辐射反射回太空来做到这一点。然而，位于大气层高处的冰云实际上可能通过捕获和释放热辐射而在地表造成变暖效应。冷却与加热冰的相对量取决于高云中冰粒的数量和大小。我们目前在真实大气中的测量未能量化这些云的辐射特性，这是因为目前在测量飞机上的小冰粒时存在仪器困难。降水也是气候变化的一个重要因素，冰粒在其中发挥了巨大作用。早在1789年，本杰明·富兰克林就提出：“大部分的雨，当它到达地球表面的时候，在它开始降落的时候可能已经是雪了. '.这是非常正确的，目前的估计认为，热带地区的大部分降水（60%）都是由冰相造成的。在我们生活的地球大气层中，温度随高度的增加而显著下降。此外，还必须考虑冰雹风暴对农作物造成的年度损失。认为冰粒是在温度低于0摄氏度时形成的，这是一个普遍的误解。目前的理论表明，只有当液态水含有足够的杂质时，才会发生这种情况。所以，例如，当水接触到一个肮脏的表面，如地面，甚至车窗-即使你的窗户是干净的，他们仍然含有足够的杂质形成冰晶-水可以冻结。然而，在大气中，水滴处于非常纯净的状态，它们中的大多数直到温度低至-35 ℃才冻结。但是大气中有一些杂质，尽管很少，如果这些粒子包含在云中，那么冰粒将在温度可能高达-5摄氏度的情况下形成。问题是，这些杂质的数量本身并不能解释在云中观察到的冰粒的数量。有几个理论已经提出来解释这一点，有些有很好的实验证据。然而，为了准确评估气候变化，我们需要定量地确定其重要性。这项工作将寻求解决上述三个问题，通过获得在模拟实验室条件下的雪形成的效率的理解，并进行实验，看看冰粒子形成的物理。曼彻斯特大学地球、大气和环境科学学院的科学家们将在一个所谓的冰瀑室中制造出逼真的云。他们将模拟自然云形成本身的物理过程，并使用最先进的仪器来探测云内的粒子。通过理解基础物理学，他们将能够与英国气象局和其他大学合作，更好地理解气候变化问题。曼彻斯特的科学家们还寻求与赫特福德郡大学、德国和美国的顶尖科学家合作，以便在这一领域取得进展。

项目成果

Microscopic Observations of Riming on an Ice Surface Using High Speed Video

• DOI: 10.1016/j.atmosres.2016.10.014
• 发表时间: 2017-03
• 期刊: Atmospheric Research
• 影响因子: 5.5
• 作者: C. Emersic;P. Connolly

The breakup of levitating water drops observed with a high speed camera

• DOI: 10.5194/acp-11-10205-2011
• 发表时间: 2011-01-01
• 期刊: ATMOSPHERIC CHEMISTRY AND PHYSICS
• 影响因子: 6.3
• 作者: Emersic, C.;Connolly, P. J.
• 通讯作者: Connolly, P. J.

A laboratory investigation into the aggregation efficiency of small ice crystals

小冰晶聚集效率的实验室研究

• DOI: 10.5194/acp-12-2055-2012
• 发表时间: 2012
• 期刊: Atmospheric Chemistry and Physics
• 影响因子: 6.3
• 作者: Connolly P

Studies of propane flame soot acting as heterogeneous ice nuclei in conjunction with single particle soot photometer measurements

结合单粒子烟灰光度计测量研究丙烷火焰烟灰作为异质冰核的作用

• DOI: 10.5194/acpd-11-11007-2011
• 发表时间: 2011
• 作者: Crawford I

Lidar atmospheric measurements on Mars and Earth

火星和地球上的激光雷达大气测量

• DOI: 10.1016/j.pss.2010.03.004
• 发表时间: 2011
• 期刊: Planetary and Space Science
• 影响因子: 2.4
• 作者: Dickinson C