Identifies which convective events originated due to local surface forcing. When θdef = 0 then the convection is identified as being triggered locally, otherwise the event was triggered by other non-local sources. When applying this distinction to model output be mindful of horizontal resolution because coarser resolutions would likely not capture the necessary surface heterogeneity. Generally grid sizes finer enough to resolve the dominate land surface type is sufficient, but the finer the better. See Figure Figures 2 and 7 from Part I, and Figures 5-8 from Part II
Quantifies that atmospheric background state by the variable θBM and hBCL. Higher θBM and hBCL translate to drier, more stable atmospheric background state with respect to convection. Practically these variables put the local surface forcing within the context of the background state. See Figure 7 from Part I, and Figure 1 from Part 2<
Helps assess whether the moisture or surface heating pathway is most efficient for triggering convection as quantified by Eadv. When Eadv is greater than 45, injecting moisture into the boundary layer through either evaporation or advection is more effective at triggering convection. When Eadv less than 45 means heating the surface is more efficient at triggering convection than injecting moisture. See Figures 5 and 6 from Part I, and Figure 9 from Part II.
Use morning measurements of the atmospheric background state, θBM, and collocated soil moisture to identify the states that are most conducive to triggering convection later in the day. This is a method for identifying positive and negative feedbacks between soil moisture and convection. See Figure 11 from Part II.
The above usages can be calculated from observations and models and then used to explore biases in convective initiation timing, atmospheric background state of convective triggering, the most energy efficient pathways for triggering, and local soil moisture-convection interactions.
Needs vertical profiles of temperature, specific humidity, pressure, and height. Works well with radiosonde data and model/reanalysis output.
Prototype Subroutine Call
How to Calculate
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
Tawfik, A., P.A. Dirmeyer, J.A. Santanello Jr. (2015), The Heated Condensation Framework. Part I: Description and Southern Great Plains Case Study, Journal of Hydromet. doi:10.1175/JHM-D-14-0117.1  Detailed Evaluation
Tawfik, A., P.A. Dirmeyer, J.A. Santanello Jr. (2015), 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