Cell-to-cell communication was characterized in cumulus-oocyte complexes from rat ovarian follicles before and after ovulation. Numerous, small gap junctional contacts were present between cumulus cells and oocytes before ovulation. The gap junction are formed on the oocyte surface by cumulus cell processes that transverse the zona pellucida and contact the oolemma. The entire cumulus mass was ...

An ensemble Kalman filter (EnKF) coupled to the Advanced Research version of the Weather Research and Forecasting (WRF) model is used to generate ensemble analyes and forecasts of a strong African Easterly Wave (AEW) during the African Monsoon Multidisciplinary Analysis field campaign. Ensemble sensitivity analysis is then used to evaluate the impact of initial condition errors on AEW amplitude...

Idealized large-eddy simulations of shallow convection often utilize horizontally periodic computational domains. The development precipitation in cumulus changes the spatial structure and creates large-scale organization. However, limited domain constrains horizontal variability atmospheric boundary layer. Small domains cannot capture mesoscale layer organization artificially constrain structu...

Vertical accelerations during the early stages of convective cloud formation are often the result of buoyancy and the perturbation vertical pressure gradient forces. Convection modifies the local pressure field surrounding the cloud. Measurement of the cloud perturbation pressure field is challenging over distance scales on the order of the convective elements, since the signals are often small...

A new stochastic multi-cloud model (SMCM) convective parametrization, which mimics the interactions at sub-grid scales of multiple cloud types, is incorporated into the National Centers for Environmental Prediction (NCEP) Climate Forecast System version 2 (CFSv2) model (referred to as CFSsmcm hereafter) in lieu of the pre-existing simplified Arakawa-Schubert (SAS) cumulus scheme. A detailed ana...

We present simulations of cumulus convection over land with shortwave radiation computed by a Monte Carlo ray tracer coupled to the flow solver. Ray tracing delivers very realistic in-cloud heating rates and global horizontal irradiance fields. The necessary performance has been enabled raw power GPU computing from techniques for accelerating data lookup convergence. used case study grassland i...

Observations have been made in six small cumulus clouds using instrumented aircraft, a ground-based radar, and a 95 GHz airborne Doppler radar. The clouds occurred on two days during the Small Cumulus Microphysics Study in east-central Florida, summer 1995. Cloud tops were below 3 km and in-cloud temperatures were warmer than 108C. Maximum observed reflectivity factors were less than 0 dBZ. The...

Trade wind regions cover most of the tropical oceans, and the prevailing cloud type is shallow cumulus. These small clouds are parameterized by climate models, and changes in their radiative effects strongly and directly contribute to the spread in estimates of climate sensitivity. This study investigates the structure and variability of these clouds in observations and climate models. The stud...