Final Report Summary - ICE (Laboratory and modelling studies of ice nucleation and crystallisation in the Earth's atmosphere)
In this project my ERC funded team has driven forward both our understanding of the formation of ice in clouds and the nature of the ice that forms. This is important because the formation of ice in clouds remains one of the least well understood aspects of clouds and the climate system. My team has made a number of major scientific advances, these include:
1) We demonstrated that feldspar is the mineral in desert dust which makes it good at nucleating ice (Atkinson et al., 2013). It was previously thought that the clay minerals were the most important component. We also used a global aerosol model to show that feldspar is one of the most important ice nucleating materials in the Earth’s atmosphere. This has changed the way our community approach ice nucleation studies by desert dust and our findings have now been borne out by other group’s research.
2) My team demonstrated that stacking disorder in ice is much more prevalent than previously thought (Malkin et al., 2015). We show that when ice crystallises from water it does not necessarily take on the normal hexagonal crystal structure, instead it takes on a form which has a degree of disorder. We have coined the term stacking disordered ice (or ice Isd for short). We went on to show that ice crystals made of this ice can take on a triangular shape and that they may be important in a range of cloud types (Murray et al., In Press).
3) We demonstrated that aqueous aerosol in a glassy state nucleate ice under conditions of upper tropospheric cirrus (Murray et al., 2010). This was a major surprise since it was thought that they would not do so. We used a cloud resolving model to show that we could explain elevated in-cloud humidity if ice crystals nucleate as they did in our experiments.
In addition to my team’s scientific achievements, I have also capitalised on our work on desert dust ice nucleants with a patent and am working with a company with the objective of improving the efficacy of cryopreservation techniques.
References
Atkinson, J. D., Murray, B. J., Woodhouse, M. T., Whale, T. F., Baustian, K. J., Carslaw, K. S., Dobbie, S., O'Sullivan, D., and Malkin, T. L.: The importance of feldspar for ice nucleation by mineral dust in mixed-phase clouds, Nature, 498, 355-358, 10.1038/nature12278 2013.
Malkin, T. L., Murray, B. J., Salzmann, C. G., Molinero, V., Pickering, S. J., and Whale, T. F.: Stacking disorder in ice I, Phys. Chem. Chem. Phys., 17, 60-76, 10.1039/C4CP02893G 2015.
Murray, B. J., Wilson, T. W., Dobbie, S., Cui, Z. Q., Al-Jumur, S., Mohler, O., Schnaiter, M., Wagner, R., Benz, S., Niemand, M., Saathoff, H., Ebert, V., Wagner, S., and Karcher, B.: Heterogeneous nucleation of ice particles on glassy aerosols under cirrus conditions, Nature Geosci., 3, 233-237, 10.1038/ngeo817 2010.
Murray, B. J., Salzmann, C. G., Dobbie, S., Heymsfield, A. J., and Neely III, R. R.: Trigonal ice crystals in the atmosphere, Bull. Am. Met. Soc., In Press.
1) We demonstrated that feldspar is the mineral in desert dust which makes it good at nucleating ice (Atkinson et al., 2013). It was previously thought that the clay minerals were the most important component. We also used a global aerosol model to show that feldspar is one of the most important ice nucleating materials in the Earth’s atmosphere. This has changed the way our community approach ice nucleation studies by desert dust and our findings have now been borne out by other group’s research.
2) My team demonstrated that stacking disorder in ice is much more prevalent than previously thought (Malkin et al., 2015). We show that when ice crystallises from water it does not necessarily take on the normal hexagonal crystal structure, instead it takes on a form which has a degree of disorder. We have coined the term stacking disordered ice (or ice Isd for short). We went on to show that ice crystals made of this ice can take on a triangular shape and that they may be important in a range of cloud types (Murray et al., In Press).
3) We demonstrated that aqueous aerosol in a glassy state nucleate ice under conditions of upper tropospheric cirrus (Murray et al., 2010). This was a major surprise since it was thought that they would not do so. We used a cloud resolving model to show that we could explain elevated in-cloud humidity if ice crystals nucleate as they did in our experiments.
In addition to my team’s scientific achievements, I have also capitalised on our work on desert dust ice nucleants with a patent and am working with a company with the objective of improving the efficacy of cryopreservation techniques.
References
Atkinson, J. D., Murray, B. J., Woodhouse, M. T., Whale, T. F., Baustian, K. J., Carslaw, K. S., Dobbie, S., O'Sullivan, D., and Malkin, T. L.: The importance of feldspar for ice nucleation by mineral dust in mixed-phase clouds, Nature, 498, 355-358, 10.1038/nature12278 2013.
Malkin, T. L., Murray, B. J., Salzmann, C. G., Molinero, V., Pickering, S. J., and Whale, T. F.: Stacking disorder in ice I, Phys. Chem. Chem. Phys., 17, 60-76, 10.1039/C4CP02893G 2015.
Murray, B. J., Wilson, T. W., Dobbie, S., Cui, Z. Q., Al-Jumur, S., Mohler, O., Schnaiter, M., Wagner, R., Benz, S., Niemand, M., Saathoff, H., Ebert, V., Wagner, S., and Karcher, B.: Heterogeneous nucleation of ice particles on glassy aerosols under cirrus conditions, Nature Geosci., 3, 233-237, 10.1038/ngeo817 2010.
Murray, B. J., Salzmann, C. G., Dobbie, S., Heymsfield, A. J., and Neely III, R. R.: Trigonal ice crystals in the atmosphere, Bull. Am. Met. Soc., In Press.