Studying Ice and Mixed Phase clouds using Laboratory EXperiments - SIMPLEX

Lead Research Organisation: University of Manchester
Department Name: Earth Atmospheric and Env Sciences

Abstract

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.

Publications

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Connolly P (2012) A laboratory investigation into the aggregation efficiency of small ice crystals in Atmospheric Chemistry and Physics

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Dickinson C (2011) Lidar atmospheric measurements on Mars and Earth in Planetary and Space Science

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Emersic C (2011) The breakup of levitating water drops observed with a high speed camera in Atmospheric Chemistry and Physics

 
Description The project key findings are as follows:

1. Ice crystal aggregation (snow formation) efficiencies have been measured and quantified for the first time

2. Ice crystal growth by vapour deposition and ice crystal fall speed parameterisations are shown to perform well when compared to data.

3. Numerical models that treat clouds may suffer from numerical diffusion (artificial smearing out) unless care is taken. This is important when quantifying cloud processes in a laboratory setting and quantitatively modelling clouds.

4. Raindrop break up parameterisations are shown to be inadequate when explaining the break-up of large mm sized drops. Necessary fixes have been derived.

5. Work in progress involves calibration of state of the art cloud probes - paper in progress and quantitative measurements of ice crystal formation relevant to the atmosphere.
Exploitation Route The cloud chamber is being used to investigate how LEDs perform as runway lights in fogging conditions, as opposed to the old halogen type bulbs. It is through the funding received that we are able to do this research. The microphysical processes investigated can be input into numerical weather models to enable more accurate, physically based, parameterisations of clouds and precipitation.
We have been discussing how the findings on ice crystal aggregation (and ways of modelling it) can be included in Met Office models.
Sectors Environment

URL http://data.cas.manchester.ac.uk/micc/micc.htm
 
Description The findings have been used to improve model descriptions of cloud processes. It is expected that these improvements may feed into improvements in numerical weather forecast models. However, this impact is a work in progress.
First Year Of Impact 2012
Sector Environment
Impact Types Economic,Policy & public services

 
Description ACID-PRUF NERC directed program
Amount £1,083,850 (GBP)
Funding ID NE/I020121/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 09/2011 
End 03/2015
 
Description Consortium
Amount £839,084 (GBP)
Funding ID NE/J010073/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 03/2012 
End 03/2016
 
Description Standard grants
Amount £644,966 (GBP)
Funding ID NE/L007827/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 08/2014 
End 08/2017
 
Description Standard grants
Amount £461,074 (GBP)
Funding ID NE/J022594/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 10/2012 
End 10/2015
 
Title New software for processing cloud particle imager data 
Description The community use instruments to measure / image cloud particles at ground-based, laboratory and using aircraft platforms. An important instrument is the cloud particle imager. Software to process these data and images and to classify them has been written and made available to the public, here: https://github.com/maul1609/CPI-3V-processing 
Type Of Material Improvements to research infrastructure 
Year Produced 2018 
Provided To Others? Yes  
Impact To early to tell 
URL https://github.com/maul1609/CPI-3V-processing
 
Title Development of a research model: The Aerosol Cloud and Precipitation Interactions Model 
Description The Aerosol-Cloud and Precipitation Interactions Model (ACPIM) is a numerical model of aerosol, cloud and precipitation interactions. It was written and tested at the University of Manchester by me. It is a very detailed cloud microphysics model. 
Type Of Material Computer model/algorithm 
Year Produced 2011 
Provided To Others? Yes  
Impact Further collaborations / funding have resulted from this development. It has also been a useful resource for the training of PhD students. 
URL http://personalpages.manchester.ac.uk/staff/paul.connolly/research/acpim01.html
 
Title The Aerosol-Cloud and Precipitation Interactions Model 
Description The Aerosol Cloud and Precipitation Interactions Model is a detailed cloud microphysical model written in the Fortran-90 language by me. It is a useful tool for understanding how aerosols and cloud microphysical processes interact. 
Type Of Technology Software 
Year Produced 2012 
Open Source License? Yes  
Impact International collaboration, useful tool in the training of PhD students. 
URL http://personalpages.manchester.ac.uk/staff/paul.connolly/research/acpim01.html
 
Description Appearance on the BBC's Newsround 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact I was interviewed by the BBC's Newsround, which featured the cloud chamber I was using for my research. At the time this was because of large interest in snow because of the recent disruption to services by the winter weather. It generated further interest from the media.
Year(s) Of Engagement Activity 2009
URL http://news.bbc.co.uk/cbbcnews/hi/newsid_8420000/newsid_8420300/8420340.stm
 
Description Appearance on the BBC's The One Show 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact I was interviewed by Carol Kirkwood on the BBCs The One Show about how snow forms in the atmosphere. We then made snow in the lab, which sparked further interest from potential students.
Year(s) Of Engagement Activity 2009
URL http://www.bbc.co.uk/programmes/b00p99rd
 
Description Article published in New Scientist 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact New Scientist contacted and interviewed me and asked to write an article about my research. This led to further interest from the media.
Year(s) Of Engagement Activity 2008
URL https://www.newscientist.com/article/mg20026876-600-snowflake-maker-to-improve-weather-forecasts/
 
Description BBC documentary: Bang Goes The Winter Weather. 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact This was a special hour-long edition of Bang Goes the Theory where the science of snow / rain formation was covered in detail. In this episode I showed them our cloud chamber at Manchester and acted as a "consultant" to tell them how they could make their own huge cloud chamber. This was useful as it generated interest from future PhD students.
Year(s) Of Engagement Activity 2011
URL http://www.bbc.co.uk/programmes/b00zf9vx
 
Description BBC documentary: Will It Snow? 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact This aired during prime time on the BBC because of the recent large snowfalls over the UK and disruption to services. It talked about the different kinds of snow and how they form. This led to further interviews and interest in my research.
Year(s) Of Engagement Activity 2011
URL http://www.bbc.co.uk/programmes/b0175m9n
 
Description Invited lecture at the Institute of Physics on the physics of snow. 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Undergraduate students
Results and Impact I was invited to give the Christmas lecture at the Institute of Physics in Lancaster in 2009. The audience was mainly undergraduate physics students and sparked interest / discussion in the subject.
Year(s) Of Engagement Activity 2009
 
Description Podcast about my research 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact I was interviewed by NERCs Planet Earth in my laboratory and talked about clouds and aerosol particles. The Podcast made use of the various "atmospheric" sounds in the lab, turning valves, rushing air, etc. It was used as a resource to share out with pupils when performing outreach at Schools, etc.
Year(s) Of Engagement Activity 2009
URL http://planetearth.nerc.ac.uk/multimedia/story.aspx?id=600&cookieConsent=A