5 Properties of the transition to strong deep convection, as previously observed in satellite pre6 cipitation statistics, are analyzed using parcel stability computations and a convective plume 7 velocity equation. A set of alternative entrainment assumptions yield very different char8 acteristics of the deep convection onset boundary (here measured by conditional instability 9 and plume vertic...

A method is described for parameterizing thermodynamic forcing by the mesoscale updrafts and downdrafts of mesoscale convective systems (MCSs) in models with resolution too coarse to resolve these drafts. The parameterization contains improvements over previous schemes, including a more sophisticated convective driver and inclusion of the vertical distribution of various physical processes obta...

n Flight delays are now a major problem in the U.S. National Airspace System. A significant fraction of these delays are caused by reductions in en route capacity due to severe convective weather. The Corridor Integrated Weather System (CIWS) is a fully automated weather analysis and forecasting system designed to support the development and execution of convective weather impact mitigation pla...

The Madden-Julian oscillation (MJO) skeleton model is a low-order model for intraseasonal oscillations that, in an extended form, includes off-equatorial and antisymmetric components. Previous studies of this extended model have used an idealized background state and forcing terms. In the current study, observation-based estimates of these forcing terms and background state are used. Linear sol...

The effective management of convective weather in congested airspace requires decision support tools that can translate weather information available to air traffic managers into anticipated impact on air traffic operations. The Convective Weather Avoidance Model (CWAM) has been under development at Lincoln Lab under sponsorship of NASA to develop a correlation between pilot behavior and observ...

Although severe thunderstorms are one of the primary causes of catastrophic loss in the United States, their response to elevated greenhouse forcing has remained a prominent source of uncertainty for climate change impacts assessment. We find that the Coupled Model Intercomparison Project, Phase 5, global climate model ensemble indicates robust increases in the occurrence of severe thunderstorm...

The propagation of a reaction front through a packed bed is analyzed theoretically. The chemical reaction rate is represented by Arrhenius temperature kinetics with external transfer limitation and general power law dependency on both gaseous and solid reactant concentrations. Analogous to so-called “Activation Energy Asymptotics” developed for premixed laminar flames, the largeness of the acti...

In previous work, we have shown that recent updated standard solar models cannot reproduce the radial profile of the sound speed at the base of the convective zone and fail to predict the photospheric lithium abundance. In parallel, helioseismology has shown that the transition from differential rotation in the convective zone to almost uniform rotation in the radiative solar interior occurs in...

Loblolly pine trees (Pinus taeda L.) occupy more than 20% of the forested area in the southern United States, represent more than 50% of the standing pine volume in this region, and remove from the atmosphere about 500 g C m-2 per year through net ecosystem exchange. Hence, their significance as a major regional carbon sink can hardly be disputed. What is disputed is whether the proliferation o...

Recent observational analysis reveals the central role of three cloud types, congestus, stratiform, and deep-convective cumulus clouds, in the dynamics of large scale convectively coupled Kelvin waves, westward propagating 2-day waves, and the Madden–Julian oscillation. Recently, a systematic model convective parametrization highlighting the dynamic role of the three cloud types has been develo...