Ice NUcleation Process Investigation And Quantification

In this proposal we are seeking funds to take part in a field campaign that we have been invited to contribute to, which has international participants, is multidisciplinary, and will study aerosol-cloud interactions at the Jungfraujoch mountain site in the Swiss Alps in winter 2013.

This is a cost effective and timely project, building on previous NERC investment.

The Earth's radiation budget is very greatly affected by clouds, and human-induced changes to the particle loading affecting them, known as indirect effects, are large and highly uncertain. A large part of this uncertainty is the result of poor knowledge of the fundamental aerosol and cloud properties and processes, leading to their poor representation in the current state-of-the-science models. Indeed the IPCC did not have any assessment of the sign, let alone the uncertainty in radiative forcing, which was attributable to the effects of aerosols on ice clouds as they thought that the uncertainties were at present too large.

Hypotheses:
1. That the rapid transitions between ice and mixed phase / liquid clouds are due to aerosol-cloud interactions.
2. That the number of ice crystals within the clouds observed at Jungfraujoch can be explained by the heterogeneous IN observed at a site upwind of the clouds
3. That laboratory derived ice nucleation parameterisations, based on surrogates of atmospheric particles (e.g. dust, biological particles, soot) are adequate to explain primary ice formation rates within the clouds.
4. That the ice-ice aggregation rates derived from the NERC SIMPLEX project (PI: Connolly) can be used to explain ice-ice aggregation in the real atmosphere.
5. That the secondary ice multiplication is a strong contributor to ice within these clouds.

We propose to gain further insight into these problems and test these hypotheses by conducting a field campaign followed by extensive data analysis and modelling.

The field campaign will have several novel facets:
1. State-of-the-science cloud microphysics measurements, including, 2DS and CPI-3V.
2. Novel measurements of biological, dust, black carbon, volatile and total aerosols as well as their enrichment within ice particles at the site.
3. Measurements of ice nuclei using IN counters, both at the site (in-cloud) and at an upwind site.
4. A proven collaboration with international partners, involving scientists from Switzerland and several institutes in Germany.
5. Expertise from NCAS instrument scientists in the deployment of instruments into the field.
6. Measurements of profiles of aerosols and turbulence using lidar at the upwind site.

In order to interpret the measurements we will use a detailed aerosol-cloud and precipitation interactions model, developed at Manchester as part of the APPRAISE research programme by the PI: Connolly. This will enable us to take the aerosols measured at two sites and use them to test ice nucleation parameterisations in the model and verify them against data from ice nucleus counters and in-cloud measurements of ice crystal concentrations. The model will be used to derive enrichment factors for the different particles. It will also allow us to address the various objectives.

The data analysis and modelling program will benefit from:
1. Expertise from NCAS instrument scientists in the analysis of data and derivation of data products.
2. PDRA: Christopher Dearden who has a range of expertise in modelling cloud microphysical processes using both mesoscale models and detailed bin microphysics models.
3. PDRA: Ian Crawford who has a range of expertise in field deployment of microphysics probes and interpretation.
4. Close collaboration with colleagues in the field ice nucleation and parameterisation so that the latest developments can be incorporated into the analysis.

We feel that there is the potential to make large gains here by bringing together world leading scientists to the same field campaign with similar, but distinct aims.

We have a clear pathway to impact throughout; this involves:
1. Inviting a film crew to attend the project and film a documentary that can be disseminated via national television. PI: Paul Connolly has worked closely with the media and has made appearances on television to describe his research (Bang goes the winter weather, The One Show, Newsround). These programs carry a certain amount of impact as they disseminate to large numbers and affect public opinion on topics such as climate change.
2. Producing Podcasts of various aspects of the work - via Manchester PDRAs - using `the Barometer' podcast. These links are distributed to schools and colleges and also advertised on our departmental web pages.
3. Visiting schools in the local area to enrich school children's education - Both PDRA: Chris Dearden and PI: Paul Connolly have links with schools in the area and are involved this kind of outreach. Chris Dearden especially who was an Ogden Teaching Fellow during his PhD.
4. Collaborating with climate modellers who have input into the IPCC who will use the results to inform their model development of key processes describing ice formation and evolution within clouds.
5. Collaboration with the Met Office who will use the results to inform their model development activities and ultimately improve weather forecasting services.
6. Working closely with instrument developers, Biral-UK, who wish to test and validate a new prototype instrument in the extreme conditions at the site.

A UK web site will be set up, linked to the UK NCAS web site, which will describe the project and its outcomes with specific areas designed for both the scientific user as well as lay communities. A good example of a web site designed by one of our PDRA's to engage the wider community can be seen at http://data.cas.manchester.ac.uk/micc/micc.htm.

In addition, a video podcast will be produced describing the experiment and its science during the intensive field experiments. This will be made freely available to interested parties via the i-Tunes Education Site as well as the University of Manchester "Barometer: web site run by CAS research students.

To extend the impact of the programme into the public sector INUIT is developing web-based educational materials that will explain the impact of climate change in the study area. This will extend to providing real-time data from the Jungfraujoch Sphinx Laboratory. The data and internet systems that allow for the display of real time data are already in place, as are the necessary resources for website development. This proposal will contribute to this by providing real-time biological aerosol data.