Convection: Initiation and Growth
Although there have been tremendous strides in understanding how convection is triggered, develops, and sustained, there are still gaps in the when, where, and how particularly in the context of forecast and climate models with coarse resolution. It is well-recognized for example that climate models tend to trigger convection too early in the day and also tend to have more drizzle than observed. On the forecasting side, even high resolution convection-permitting models oftentimes fail to capture area of initiation and growth of storms beyond several hour lead times. Addressing these issues can quickly improve response times allowing industry and municipalities to strategically position assets ahead of storms, and help individuals plan accordingly.
With the mission of helping address these issues, my research has been focused on exploring how to better understand the processes involved in convective initiation. In particular I have developed a suite of variables and metrics that can be used to understand how “close” an atmospheric profile is to convection and how probability of trigger convection. This framework is referred to as the Heated Condensation Framework (HCF) and only requires routinely measured temperature and humidity vertical profiles to calculate the full suite of variables.
Tawfik, A., D.M. Lawrence, and P.A. Dirmeyer (2016), Representing sub-grid convective initiation in CESM, JAMES (In-Review)
Chen, L., Dirmeyer, P.A., Tawfik, A., and Lawrence D.M. (2016), Sensitivity of Land Cover-Precipitation Feedback to Convective Triggering (In-Review)
Itterly, K., Taylor, P., Dodson, J., Tawfik, A. (2016), On the Sensitivity of the Diurnal Cycle in the Amazon to Convective Intensity, J. Geophys. Res., 21, doi:10.1002/2016JD025039
Bombardi, R., Tawfik, A., Marx, L., Shin, C., Schneider, E., Dirmeyer, P.A., and Kinter III, J.L., The Heated Condensation Framework as a Convective Trigger in the NCEP Climate Forecast System version 2, J. Adv. Model. Earth Syst., Accepted Author Manuscript. doi:10.1002/2016MS000668
Tawfik, A., P.A. Dirmeyer, J.A. Santanello Jr., The Heated Condensation Framework. Part I: Description and Southern Great Plains Case Study, Journal of Hydromet. doi:10.1175/JHM-D-14-0117.1
Tawfik, A., P.A. Dirmeyer, J.A. Santanello Jr., The Heated Condensation Framework. Part II: Climatological behavior of convective initiation and land-atmosphere coupling over the Continental United States, Journal of Hydromet. doi:10.1175/JHM-D-14-0118.1
Tawfik, A.B., and P.A. Dirmeyer (2014), A process-based framework for quantifying the atmospheric preconditioning of surface-triggered convection, Geophys. Res. Lett., 41, doi:10.1002/2013GL057984
Bombardi, R., Schneider, E., Marx, L., Halder, S., Singh, B., Tawfik, A., Dirmeyer, P.A., and Kinter III, J.L., Improvements in the representation of the Indian Summer Monsoon in the NCEP Climate Forecast System version 2, Climate Dynamics, doi:10.1007/s00382-015-2484-6