Meoscale weather systems over Montserrat, an active volcanic island in the Caribbean
Supervisers – Ian Renfrew, Adrian Matthews
Atmospheric flow over and round isolated mountains has been the subject of much scientific study. Theoretical, laboratory-based and numerical studies have determined regimes where flow tends to pass over or around the obstacle depending upon, e.g., the flow speed, the height of the mountain, the atmospheric stability, the Coriolis force, and so on (e.g. Smith 1989). This project will extend that work to the study of the flow around an isolated active volcano. The major difference will be the large surface temperature anomaly associated with hot lava and volanic rocks at, or near, the surface of the volcano. Such a temperature anomaly will act to change the local atmospheric circulation, for example, enhancing convection over the anomaly. Further consideration suggests there may be other interesting and important volcano-weather system interactions, e.g. enhanced cloud formation aided by the ready supply of volcanic gases being vented. Little research has previously been carried out on such mesoscale volcano-weather system interactions. Previous climate studies have focused on the long-term global impacts of major volcanic eruptions, such as from Mt Pinatubo (e.g. Robock, 2000).
Montserrat, in the Lesser Antilles island chain in the Caribbean Sea, is just such an isolated active volcano – the island is approximately 16 by 11 km in size. The Soufrière Hills Volcano (SHV), dominates the island, rising dramatically to a peak of approximately 1000 m, depending on whether its volcanic dome is currently growing or has recently collapsed. Previously dormant, the SHV started erupting in July 1995 and has been active ever since, with various major eruptive periods.
Montserrat has been a focus of attention for volcanology, sedimentology and meteorology here at UEA. Recent work has investigated the role that heavy precipitation plays in triggering volcanic eruptions (Matthews et al., 2002; Matthews and Barclay, 2004; Barclay et al., 2006) and lahars. We have built up a precipitation data set covering the last 8 years.
This PhD will involve a climatological analysis for the island of Montserrat and dedicated mesoscale atmospheric modelling of particular cases. The modelling studies will include several simple parameterisations for the effect of the volcano on the atmosphere.
Further reading
Barclay J, Johnstone JE, Matthews AJ, 2006: Meteorological monitoring of an active volcano: Implications for eruption prediction. J. Volcanol. Geotherm. Res., 150, 339-358.
Matthews AJ, Barclay J, 2004: A thermodynamical model for rainfall-triggered volcanic dome collapse. Geophys. Res. Lett., 31 (5), L05614.
Matthews AJ, Barclay J, Carn S, Thompson G, Alexander J, Herd R, Williams C, 2002: Rainfall-induced volcanic activity on Montserrat. Geophys. Res. Lett., 29 (13), 1644.
Robock A. 2000. Volcanic eruptions and climate. Rev. Geophys. 38: 191–219.
Smith, RB. 1989. Hydrostatic Air-Flow Over Mountains. Advances In Geophysics 31: 1-41.
Smith, RB; Gleason, AC; Gluhosky, PA; Grubisic, V. 1997. The wake of St. Vincent. Journal of the Atmospheric Sciences 54 (5): 606-623.