Christopher Thorncroft

Christopher D. Thorncroft

Studies tropical weather and climate with an emphasis on variability of West African monsoon rainfall, tropical waves and Atlantic hurricanes

The World Within Reach
Christopher D. Thorncroft

College of Arts and Sciences
Department: Atmospheric and Environmental Sciences

ES 226



University of Bristol      Physics           BSc Hons   1984
University of Reading   Meteorology   MSc            1985
University of Reading   Meteorology   PhD            1988

Research Interests

My research is mainly focused on improving our understanding of the West African monsoon and how it impacts Atlantic tropical cyclone variability. The research spans a wide range of timescales from diurnal to multidecadal. At the weather scale my research is focused on understanding the physical processed that impact the nature  and variability of African easterly waves (AEWs). This includes a special emphasis on how AEWs interact with the ubiquitous mesoscale convective systems and ultimately how this affects the probability that AEWs will help spawn tropical cyclones. Recent work at the weather scale has also emphasized the role of convectively coupled equatorial waves on the West African monsoon and Atlantic tropical cyclogenesis frequency. At the climate scale I am interested in better understanding the annual cycle of the West African monsoon as well as the processes that impact interannual to decadal variability and predictability of Sahel rainfall.


* indicates a student or post doc.

Thorncroft, C.D. and Hoskins, B.J. 1990: Frontal Cyclogenesis. J. Atmos. Sci., 47, 2317-2336.

Thorncroft, C.D., Hoskins, B.J. and McIntyre, M.E. 1993: Two paradigms of baroclinic wave life-cycle behaviour. Q.J.R. Meteorol. Soc., 119, 17-55.

Thorncroft, C.D. and Hoskins, B.J. 1994: An idealized study of African easterly waves. I: A linear view. Q.J.R. Meteorol. Soc., 120, 953-982.

Thorncroft, C.D. and Hoskins, B.J. 1994: An idealized study of African easterly waves. II: A non-linear view. Q.J.R. Meteorol. Soc., 120, 983-1015.

Thorncroft, C.D. 1995: An idealized study of African easterly waves. III: More realistic basic states Q.J.R. Meteorol. Soc., 121, 1589-1614.

Thorncroft, C.D. and Haile*, M. 1995: The mean dynamic and thermodynamic fields for July 1989 over tropical north Africa and their relationship to convective activity. Mon. Wea. Rev., 123, 3016-3031.

Thorncroft, C.D. and Flokas, H. 1997: A case study of Saharan cyclogenesis. Mon. Wea. Rev., 125, 1147-1165.

Hodges, K.I. and Thorncroft, C.D. 1997: Distribution and statistics of African mesoscale convective weather systems based on the ISCCP METEOSAT imagery. Mon. Wea. Rev., 125, 2821-2837.

Jones, C.G. and Thorncroft, C.D. 1998: The role of El Nino on Atlantic tropical cyclone activity. Weather, 53, 324-336.

Thorncroft, C.D. and Rowell, D. 1998: Interannual variability of African easterly waves in a GCM. Int. Jour. Clim., 18, 1305-1323.

Thorncroft, C.D. and Blackburn, M.1999: Maintenance of the African easterly jet. Q.J.R. Meteorol. Soc., 125, 763-786.

Pytharoulis*, I. and Thorncroft, C.D. 1999: The low-level structure of African easterly waves in 1995. Mon. Wea. Rev., 127, 2266-2280.

Thorncroft, C.D. and Jones, S.C. 2000: The extratropical transitions of hurricane Felix and Iris in 1995. Mon. Wea. Rev., 128, 947-972.

Thorncroft, C.D. and Hodges, K.I. 2001: Interannual variability of African easterly wave activity and its relationship to tropical cyclone activity. J. Climate, 14, 1166-1179.

Thorncroft, C.D. and Pytharoulis*, I. 2001: A dynamical approach to seasonal prediction of Atlantic tropical cyclone activity. Weather and Forecasting, 16, 725-734.

Thorncroft, C.D., Parker, D.J., Burton, R.R., Diop, M., Ayers, J.H., Barjat, H., Dumelow, R., Kindred, D.R., Price, N.M., Saloum, M., Taylor, C.M. and Tompkins, A.M. 2003: The JET2000 experiment: Aircraft observations of the African easterly jet and African easterly waves. Bull. Amer. Met. Soc., 84, 337-351.

Hodges, K.I., Hoskins, B.J., Boyle, J. and Thorncroft, C. 2003: A comparison of recent reanalysis datasets using objective feature tracking: storm tracks and tropical easterly waves.  Mon. Wea. Rev., 131, 2012-2037.

Jones, S.C., Harr, Abraham, Bosart, Bowyer, Evans, Hanley, Hanstrum, Hart, Lalaurette, Sinclair, Smith and Thorncroft, C.D. 2003: The extratropical transition of tropical cyclones: forecast challenges, current understanding and future directions  Weather and Forecasting 18, 1052-1092.

Taylor, C.M., Ellis, R.J., Parker, D.J., Burton, R.R. and Thorncroft, C.D. 2003: Linking boundary layer variability with convection – a case study from JET2000, Q.J.R. Meterol. Soc, 129, 2233-2254.

Agusti-Panareda*, A., Thorncroft, C.D., Craig, G.C. and Gray, S.L. 2004: The extratropical transition of hurricane Irene (1999): A potential vorticity perspective. Q.J.R. Meteorol. Soc., 130, 1047-1074.

Agusti-Panareda*, A., Gray, S.L., Craig, G.C. and Thorncroft, C. D. 2005: Extratropical transition of tropical cyclone Lili (1996), Q.J.R. Meteorol. Soc., 1562-1573.

Berry*, G., and Thorncroft, C. 2005: Case study of an intense African easterly wave. Mon. Wea. Rev., 133, 752-766.

Parker, D., Thorncroft, C., Burton, R. and Diongue, A. 2005: Analysis of the African easterly jet using aircraft observations from the JET2000 experiment. Q.J.R. Meteorol. Soc, 1461-1482.

Taylor, C. M., Parker, D. J., Lloyd, C .R. and Thorncroft, C. D. 2005: Observations of synoptic scale land surface variability and its coupling with the atmosphere’, Q.J.R. Meteorol. Soc., 131, 913-938.

Tompkins, A.M., Diongue, A., Parker, D. J., and Thorncroft, C. D. 2005: The African easterly jet in the ECMWF Integrated forecast system: 4DVar analysis, Q. J. R. Meteorol. Soc., 131, 2861-2886

Parker, D.J., Burton, R., Diongue, A.,  Ellis, R.J.,  Felton, M., Taylor, C. M., Thorncroft, C.D., and Bessemoulin, P. 2005: The diurnal cycle of the west African monsoon circulation, Q. J. R. Meteorol. Soc., 131, 2839-2860.

Aiyyer*, A. and Thorncroft, C. 2006: Climatology of vertical shear over the tropical Atlantic J. Climate, 19, 2969-2983

Mohr, K. and Thorncroft, C.  2006: Intense convective systems in West Africa and their relationship with the African easterly jet , Q.J.R. Meteorol. Soc. 132, 163-176

Mekonnen*, A., Thorncroft, C. and Aiyyer, A. 2006: On the significance of African easterly waves on convection, J. Climate, 19, 5405-5421

Hall, N., Kiladis, G. and Thorncroft, C. 2006: Three-dimensional structure and dynamics of  African easterly waves: part II: Dynamical modes and growth mechanisms, J. Atmos. Sci., 63, 2231-2245.

Kiladis, G., Thorncroft, C. and Hall, N. 2006: Three-dimensional structure and dynamics of African easterly waves: part I: Observed structures, J. Atmos. Sci., 63, 2210-2230.

Berry*, G., Thorncroft, C. and Hewson, T. 2006: African easterly waves in 2004 – Analysis using objective techniques  Mon. Wea. Rev., 133, 752-766

Redelsperger, J.L., Thorncroft, C.D., Diedhiou, A., Lebel, T., Parker, D.J. and Polcher, J. 2006: African Monsoon Multidisciplinary Analysis: An International Research Project and Field Campaign, BAMS, 1739-1746.

Hopsch*, S.B., Thorncroft, C., Hodges, K. I. and Aiyyer, A. 2007: West African storm tracks and their relationship with tropical cyclones, J. Climate, 20, 2468-2483.

Parker, D.J., Fink, A., Janicot, S., Ngamini, J.-B., Douglas, M., Afiesimama, E., Agusti- Panareda, A., Beljaars, A., Dide, F., Diedhiou, A., Lebel, T., Polcher, J., Redelsperger, J.-L., Thorncroft, C.D, Wilson, G.A. 2008: The AMMA radiosonde program and its implications for the future of atmospheric monitoring over Africa, BAMS. 89, 1015-1027.

Zhang, C., Nolan, D., Thorncroft, C.D. and Nguyen*, H. 2008: Shallow Meridional Circulations in the Tropical Atmosphere, J. Climate, 21, 3453-3470.

Janicot, S., Thorncroft, C. D., and many co-authors 2008: Large-scale overview of the summer monsoon over West Africa during the AMMA field experiment in 2006. Ann. Geophys, 26, 2569-2595.

Thorncroft, C.D., Hall, N. and Kiladis, G., 2008: Three-dimensional structure and dynamics of African easterly waves: part III: Genesis, J. Atmos. Sci., 65, 3596-3607.

Mekonnen*, A., Thorncroft, C.D., Aiyyer, A. and Kiladis, G., 2008: Convectively coupled Kelvin waves over tropical Africa during boreal summer: Structure and Variability, J. Climate, 21,.6649-6667.

Cornforth*, R.J., Hoskins, B.J. and Thorncroft, C.D. 2009: The impact of moist processes on the African Easterly Jet-African Easterly Wave system, Q. J. R. Meteorol. Soc., 135, 894-913.

Mohr, K. I., Molinari, J. and Thorncroft, C.D. 2009: The interannual variability of cumulative frequency distributions for convective system size and intensity, J. Climate, 22, 5218-5231.

Hopsch*, S.B., Thorncroft, C.D. and Tyle, K.R. 2010: Analysis of African Easterly Wave Structures and their Role in Influencing Tropical Cyclogenesis, Mon. Wea. Rev., 138, 1399-1419.

Lebel, T., Parker, D.J., Flamant, C., Bourles, B., Marticorena, B., Mougin, E., Peugeot, C., Diedhiou, A., Haywood, J.M., Ngamini, J.B., Polcher, J., Redelsperger, J.-L., Thorncroft, C.D. 2010: The AMMA field campaigns: multiscale and multidisciplinary observations in the West African region, Quart. Jour. Roy. Meteorol. Soc., 136, 8-33.

Agusti-Panareda, A., Beljaars, A., Cardinali, C., Genkova, I. and Thorncroft, C.D. 2010: Impact of assimilating AMMA soundings on ECMWF analyse and forecasts, Weather and Forecasting, 25, 1142-1160.

Thorncroft, C.D., Nguyen*, H., Zhang, C. and Peyrille*, P. 2011: Annual Cycle of the West African Monsoon: Regional Circulations and associated Water Vapor Transport, Quart. Jour. Roy. Meteorol. Soc., 137, 129-147.

Aiyyer*, A. and Thorncroft, C.D. 2011: Interannual to Multidecadal Variability of Vertical shear and Tropical Cyclone Activity, J. Climate,24, 2949-2962

Nguyen*, H., Thorncroft, C. D. and Zhang, C. 2011: Guinean coastal rainfall of the West African Monsoon. Quarterly Journal of the Royal Meteorological Society, 137, 1828–1840.

Ventrice*, M. J., Thorncroft, C. D., Roundy, P. E. 2011: The Madden–Julian Oscillation’s Influence on African Easterly Waves and Downstream Tropical Cyclogenesis. Mon. Wea. Rev., 139, 2704–2722.

Polcher, J., Parker, D. J., Gaye, A., Diedhiou, A., Eymard, L., Fierli, F., Genesio, L., Höller,  H., Janicot, S., Lafore, J.-P., Karambiri, H., Lebel, T., Redelsperger, J.-L., Reeves, C. E., Ruti, P., Sandholt, I. and Thorncroft, C., 2011: AMMA's contribution to the evolution of prediction and decision-making systems for West Africa. Atmospheric Science Letters, 12: 2–6.

Lafore, J.-P., Flamant, C., Guichard, F., Parker, D. J., Bouniol, D., Fink, A. H., Giraud, V., Gosset, M., Hall, N., Höller, H., Jones, S. C., Protat, A., Roca, R., Roux, F., Saïd, F. and Thorncroft, C., 2011: Progress in understanding of weather systems in West Africa. Atmospheric Science Letters, 12: 7–12.

Lebel, T., Parker, D. J., Flamant, C., Höller, H., Polcher, J., Redelsperger, J.-L., Thorncroft, C., Bock, O., Bourles, B., Galle, S., Marticorena, B., Mougin, E., Peugeot, C.,  Cappelaere, B., Descroix, L., Diedhiou, A., Gaye, A. and Lafore, J.-P. , 2011: The AMMA field campaigns: accomplishments and lessons learned. Atmospheric Science Letters, 12: 123–128.

Wu, Man-Li C., Reale, O., Schhubert, S. D., Suarez, M. J. and Thorncroft, C. D., 2012: African Easterly Jet: barotropic instability, waves and cyclogenesis, J. Clim., 25, 1489-1510.

Ventrice*, M.J., Thorncroft, C.D. and Janiga, M. A. 2012: Atlantic tropical cyclogenesis: A three-way interaction between an African easterly wave, diurnally varying convection, and a convectively coupled atmospheric Kelvin wave, Mon. Wea. Rev. 140, 1108-1124.

Berry*, G. and Thorncroft, C. D., 2012: African Easterly Wave Dynamics in a Mesoscale Numerical Model: The Upscale Role of Convection, J. Atmos. Sci., 69, 1267-1283.

Waliser et al 2012: The “Year” of Tropical Convection (May 2008-April 2010) Climate Variability and Weather Highlights, Bull. American. Meteorol. Soc., 1189-1218.

Ventrice*, M.J., Thorncroft, C.D. and Schreck, C. J.  2012: Impacts of convectively coupled Kelvin waves on environmental conditions for Atlantic tropical cyclogenesis, Mon. Wea. Rev. 140, 2198-2214.

Zhou, L., Tian, Y., Baidya, R., Thorncroft, C., Bosart, L. F. and Hu, Yuanlong, 2012: Impacts of wind farms on land surface temperature, Nature Climate change, 2, 539-543.

Ventrice*, M.J. and Thorncroft, C.D. 2013,  The role of convectively coupled atmospheric Kelvin waves on African easterly wave activity, Mon. Wea. Rev., 141(6), 1910-1924.

Martin*, E. R. and Thorncroft, C. D. 2013: The impact of the AMO on the West African monsoon annual cycle. Q.J.R. Meteorol. Soc.. doi: 10.1002/qj.2107

Vera, C., Gutowski, W., Mechoso, R., Goswami, B., Reason, C., Thorncroft, C.D., Marengo, J.,Hewitson, B., Hendon, H., Jones, C., and Lionello, P. 2013: Understanding and Predicting Climate Variability and Change at Regional Scales, Chapter in “Climate Science for Serving Society”, Asrar, G. M and Hurrel, J. W. (Eds), 480pp, Springer.

Janiga*, M. A. and Thorncroft, C. D. 2013: Regional Differences in the Kinematic and Thermodynamic Structure of African Easterly Waves, Quart. Roy. Meteorol. Soc.,  139, 1598-1614.

Ventrice*, M.J., Wheeler, M.C., Hendon, H.H., Schreck, C.J. , Thorncroft, C.D. and Kiladis, G. N. 2013: A modified multivariate Madden Julian Oscillation index using velocity potential, Mon. Wea. Rev., 141, 4197-4210.

Martin*, E.R. ,Thorncroft, C.D., and Booth, B.B.B. 2014: The multidecadal Atlantic SST- Sahel rainfall teleconnection in CMIP5 simulations, J. Climate, 27, 784-806.

Dunion*, J.P., Thorncroft, C.D. and Velden, C.S. 2014: The tropical cyclone diurnal cycle, Mon. Wea. Rev., 142, 3900-3919.

Martin*, E.R. and Thorncroft, C.D. 2014: Sahel Rainfall in Multimodel CMIP5 Decadal Hindcasts, Geophys. Res. Letts. 41(6), 2169-2175.

Janiga*, M. A. and Thorncroft, C.D. 2014: Convection over Tropical Africa and the East Atlantic during the West African Monsoon: Regional and Diurnal Variability, J. Climate, 11, 4159-4188

Karam, D. B., Williams, E., Janiga*, M., Flamant, C., McGraw-Herdeg, M., Cuesta, J., Auby,   A. and Thorncroft, C. D.  2014: Synoptic scale dust emissions over the Sahara desert initiated by a moist convective cold pool in early August 2006, Q. Jour. Roy. Meteorol. Soc., 140, 2591-2607.

Brammer*, A. and Thorncroft, C.D. 2015: Variability and Evolution of African Easterly Wave Structure and the Relationship with Tropical Cyclogenesis over the Eastern Atlantic, Mon. Wea. Rev., 143, 4975–4995.

Janiga*, M.A. and Thorncroft, C.D. 2016: The Influence of African Easterly Waves on Convection over Tropical Africa and the East Atlantic, Mon. Wea. Rev., 144, 171–192.

Martin*, E.R. and Thorncroft, C.D. 2016: Representation of African Easterly Waves in CMIP5 Models, J. Clim., (in press)

Mekonnen, A. and Thorncroft, C.D. 2016: On the mechanisms that determine the 3-4 day time scale convection over East Africa, Int. Jour. Clim., (in press).