Adam J Durant

Phone: +44 (0) 117 9545400
Fax: +44 (0) 117 9253385
Email: adam.durant - atnospam -bristol.ac.uk

Postal Address:
Department of Earth Sciences
University of Bristol
Wills Memorial Building
Queens Road
BRISTOL
BS8 1RJ, UK

current research | curriculum vitae | publications | carrer development plan (internal)

Current Research: Climate forcing by dust

The global atmospheric dust load influences the radiation budget of the Earth and modifies climate. From a modelling perspective, the largest uncertainty associated with all climate change drivers is from the effects of radiative forcing by aerosol particles suspended in the atmosphere [e.g., IPCC, 2007]. The aim of this project is to develop an improved understanding of how physical properties of aerosol particles alter the global balance of incoming and outgoing radiation, and ultimately, how this influences climate. The main objective of this research is to investigate how micro-scale properties of aerosols (size, shape, mineralogy) affect radiative transfer and to determine if the treatment of aerosol radiative effects in current general circulation models (GCM) requires modification.

The project will involve: (a) improvement of existing radiative code to account for dust particle characteristics; (b) development of a global data set of dust properties that can be used in conjunction with existing emission models; and (c) application of the improved radiative scheme to simulate the impact of dust on regional and global forcing of (i) modern and (ii) past climates. In (a), a series of experiments will be performed to evaluate the importance of particle size, shape and mineral composition on radiative transfer. Sensitivity testing will be carried out using a simple forward model (based on MODTRAN) developed to corroborate satellite-based volcanic ash retrievals (VAR), which predicts the radiance spectrum at the top of the atmosphere after passing through a cloud layer with specified aerosol characteristics. A module that describes particle shape will be coupled to the model. Modelled radiances will be validated using volcanic ash retrievals for a selection of satellite-observed volcanic clouds. In (b), a novel observational atmospheric dust loading database will be developed that covers a short period (1-2 years) of recent time: the VAR will be modified to account for all mineral dust types [e.g. Gu et al., 2004] and MODIS imagery will be analysed over a 1-2 year period to provide a robust estimate of present-day atmospheric dust loading. Using a geographic resolution of 0.5° latitude-longitude and averaging over 2 month intervals, it should be possible to characterize inter-annual variability. In addition, an established record of atmospheric dust through geologic time (e.g., DIRTMAP) will be applied in the final part of the project. In (c), the effects of particle characteristics will be evaluated on both regional and global scales through modification of the radiative transfer scheme in a designated GCM, taking atmospheric dust load constraints from both the satellite-based modern-day dust record developed in this project, and a database such as DIRTMAP. Additionally, the climatic consequences of supervolcanic eruption will be investigated using a Quaternary eruption as a case study (e.g., Mount Mazama eruption, ~6.8 ka; Toba eruption, ~74 ka).

It is anticipated that collaborations will be established with the Hadley Centre, UK, and Institut Pierre-Simon Laplace, France. This project (ER 5) contributes to GREENCYCLES science objective 6 (Quantify impacts of vegetation and climate changes on atmospheric dust, and its feedbacks on CO2 and climate).

References:

IPCC (2007), Summary for Policymakers, in Climate Change 2007: The Physical Science Basis, Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, edited by S. Solomon, D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M.Tignor and H.L. Miller, Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

Gu, Y., W. I. Rose, and G. J. S. Bluth (2003), Retrieval of mass and sizes of particles in sandstorms using two MODIS IR bands: A case study of April 7, 2001 sandstorm in China, Geophys. Res. Lett., 30(15), 1805, doi:10.1029/2003GL017405

Wen, S., and W.I. Rose (1994), Retrieval of sizes and total masses of particles in volcanic clouds using AVHRR bands 4 and 5, J. Geophys. Res., 99, 5421-5431.

Publications

Accepted or in review

Durant, A. J., S. P. Harrison, B. Maher, and Y. Balkanski (2008), The QUEST Working Group on Dust and the future of dust-cycle research, CLIVAR Exchanges, April 2008.

Schultz, D.M., A.J. Durant, J.M. Straka, T.J. Garrett (2007), Reply, J. Atmos. Sci., accepted.

W.I. Rose, S. Self, P.J. Murrow, C. Bonadonna, A.J. Durant and G.G.J. Ernst (2007), Pyroclastic Fall Deposit from the October 14, 1974, Eruption of Fuego, Guatemala, Bull. Volcanol., in review.

Durant, A.J., R.A. Shaw and W.I. Rose, Ice Nucleation and Overseeding of Ice in Volcanic Clouds (2007), J. Geophys. Res. – Atmospheres, in review.

Schultz, D.M., K.M. Kanak, J.M. Straka, R.J. Trapp, B.A. Gordon, D.S. Zrnic, G.H. Bryan, A.J. Durant, T.J. Garrett, P. M. Klein and D. K. Lilly (2006), The Mysteries of Mammatus Clouds: Observations and Formation Mechanisms, J. Atmos. Sci., 63(10), 2409–2435.

2005

Shaw, R.A., A.J. Durant and Y. Mi (2005), Heterogeneous surface crystallization observed in undercooled water. J. Phys. Chem. B, 109, 9865-9868.

Durant, A.J., and R.A. Shaw (2005), Evaporation Freezing by Contact Nucleation Inside-Out, Geophys. Res. Lett., 32, L20814, doi:10.1029/2005GL024175.

Research-Related Articles

Sastry (2005), Water: Ins and outs of ice nucleation, Nature, 438(7069), 746.

Peer-Reviewed Conference Presentations (presenting author underlined)

Mann, C.P., H. Delgado Granados, R. Escobar Wolf, A.J. Durant and 10 others (2007), Earth Hazards Consortium: a Novel Approach to Student Education in Geoscience, Eos Trans. AGU, Jt. Assem. Suppl., Session ED05, in review.

Durant, A.J., W.I. Rose, C.J. Horwell, A.M. Sarna-Wojcicki, E. Wan, S. Dartevelle and A.C. Volentik (2006), Reanalysis of the Pyroclastic Fall Deposit from the 18 May 1980 Eruption of Mount Saint Helens, USA, Eos Trans. AGU, 87(52), Fall Meet. Suppl., Abstract V33B-0656.

Servranckx, R., A.J. Durant, A. Malo, R. D'Amours, S. Trudel and J. Gauthier (2006), Trajectory Analysis of Volcanic Clouds Produced by the 1992 Eruptions of Mount Spurr, Alaska, Eos Trans. AGU, 87(52), Fall Meet. Suppl., Abstract V22B-04.

Rose, W.I., A.J. Durant and C.J. Horwell (2006), The formation and fate of fine volcanic ash, Eos Trans. AGU, 87(52), Fall Meet. Suppl., Abstract V21C-01.

Rose, W.I., A.J. Durant and C.J. Horwell (2006), Fate of fine basaltic ash from subplinian eruptions of Fuego, Guatemala 1973-74, Eos Trans. AGU, 87(52), Fall Meet. Suppl., Abstract V33B-0648.

Carter, A.J., M.S. Ramsey, A.J. Durant, I.P. Skilling (2006), Multitemporal 3-D Imaging of Volcanic Products on the Macro- and Micro- Scale, Eos Trans. AGU, 87(52), Fall Meet. Supl., Abstr. V53B-1752.

Mann, C.P., H.D. Granados, A.J. Durant and 7 others (2006), Earth Hazards Consortium: a Unique Approach to Student-Centered Learning, Eos Trans. AGU, 87(52), Fall Meet. Suppl., Abstr. ED21A-1222.

Durant, A.J., W.I. Rose, R.A. Shaw and A.B. Kostinski (2005), A Meteorological Approach to Calculate Volcanic Cloud Parameters, Eos Trans. AGU, 86(52), Fall Meet. Suppl., Abstract V31D-0648.

Shaw, R.A., and A.J. Durant (2005), Contact Nucleation Linked to ‘Evaporation Freezing’, Eos Trans. AGU, 86(52), Fall Meet. Suppl., Abstract A23C-0970.

Durant, A.J., Y. Mi, R. A. Shaw, G. G. J. Ernst, and W. I. Rose (2004), Ice Nucleation by Volcanic Ash: Influence of Composition and Morphology, paper presented at IAVCEI General Assembly, Chile.

Ernst, G.G.J., A.J. Durant, W.I. Rose, S. Self (2004), Accretionary lapilli and water-rich eruption columns: New Constraints, paper presented at IAVCEI General Assembly, Chile.

Shaw, R.A., A.J. Durant, and Y. Mi (2004), Ice Nucleation by Volcanic Ash: Contact Nucleation Inside Out, paper presented at IAVCEI General Assembly, Chile.

Mi, Y., A.J. Durant, and R.A. Shaw (2004), Laboratory Measurements of Heterogeneous Ice Nucleation: Contact Nucleation Inside-Out, paper presented at 14th Int. Conf. on Clouds and Precip., Bologna, Italy.

Durant, A.J. (2003), Ash Aggregation in Volcanic Plumes during Dispersal and Fall-out, paper presented at 1st Meeting of the IAVCEI Working Group on Modeling Tephra-Fall Hazards, Cities on Volcanoes 3, Hilo, Hawaii.

Durant, A.J., W.I. Rose, P.J. Baxter, and C.J. Horwell (2003), Mt. Hudson Revisited 12 Years on: What are the Long-Term Health Effects from Fine Ash Produced During the 1991 Eruption?, paper presented at Cities on Volcanoes 3, Hilo, Hawaii.

Durant, A.J., D.A. Swanson, and W.I. Rose (2002), Accretionary Lapilli Beds in the Keanakako'i Ash: Footprint Bearing Beds not 1790 in Age, Eos Trans. AGU, 83(47), Fall Meet. Suppl., Abstr. V12B-1433.

Durant, A.J., and G.G.J. Ernst (2002), Role of Water and Ice in Ash Aggregation: Constraints from the Upper Scoriae 1, Santorini, Greece, paper presented at Volcanic and Magmatic Studies Group Annual Meeting, London, UK.

Durant, A.J., and G.G.J. Ernst (2001), Role of Water and Ice in Ash Aggregation: Constraints from the Upper Scoriae 1, Santorini, Greece, Eos Trans. AGU, 82(47), Fall Meet. Suppl., Abstract V42D-1064.

Educational Outreach (non-peer reviewed)

Durant, A. J., C. P. Mann, J. Stix and W. I. Rose (2007),Virtual Course Promotes Student-Directed Learning, Geological Society of America Geoscience Education Division Newsletter, Summer 2007 (http://gsaged.org).