Abstract A fully unified parameterization of boundary layer and moist convection (shallow deep) is presented. The new based on the stochastic multiplume eddy-diffusivity/mass-flux (EDMF) approach, which distinguishes between convective plumes nonconvective mixing. represent both surface-forced updrafts evaporatively driven downdrafts. type (i.e., dry, shallow, or represented by not defined a priori, but rather depends near-surface updraft properties interactions environment through lateral...

Abstract A layer of intensive mixing (entrainment interface layer, [EIL]) at the top marine stratocumulus under a strong inversion has been investigated with 10 cm resolution using an ultrafast thermometer (UFT‐F; temperature), particle volume monitor PVM–100A (liquid water content), and fast forward scattering spectrometer probe (FFSSP; droplet spectra). Measurements were collected on board NCAR C‐130 aircraft during research flight RF05 DYCOMS‐II field study. The EIL consists mutual...

Large‐eddy simulations of a Lagrangian transition from vertically well‐mixed stratocumulus‐topped boundary layer to situation in which shallow cumuli penetrate an overlying thin and broken stratocumulus are compared with aircraft observations collected during the Atlantic Stratocumulus Transition Experiment. Despite complexity case long simulation period 40 h, six participating state‐of‐the‐art models skillfully consistently represent observed gradual deepening layer, negative buoyancy flux...

Abstract Anelastic and compressible solutions are compared for two moist deep convection benchmarks, a two-dimensional thermal rising in saturated moist-neutral atmosphere, three-dimensional supercell formation. In the anelastic model, pressure applied thermodynamics comes from either environmental hydrostatically balanced profile standard model or is combined with nonhydrostatic perturbations elliptic solver generalized model. The applies an explicit acoustic-mode-resolving scheme requiring...

Abstract. Differential Absorption Radar (DAR) is an emerging technique for high resolution humidity profiling inside clouds and precipitation. This study evaluates the potential of using a spaceborne DAR operating near 380 GHz water vapor absorption line to profile in mid upper troposphere, particularly deep convective systems. To quantify expected precision accuracy define optimal channel selection, we modeled radar reflectivities from large-eddy simulation fields then implemented...

Abstract Large-eddy simulation is used to investigate the effects of cold pools driven by rain evaporation on shallow-to-deep convection transition over land. The physically consistent methodologies are developed obtain a time-dependent reference ensemble without and apply interactive surface heat fluxes modeling energy water budgets. Three different ensembles contrasted. ensemble, in spirit one-dimensional single-column models, eliminates horizontally homogenizing negative buoyancy...

Abstract. The diurnal susceptibility of clouds to aerosols is examined during the transition from subtropical stratocumulus shallow cumulus regimes. Using large-eddy simulations, a six-day air mass evolution along 3800-km observed trajectory coast Peru toward equator analyzed. Pristine and polluted scenarios are simulated with forcing imposed weather reanalysis. scenario exhibits stronger variations in cloud water, fraction, albedo, enhanced entrainment suppressed precipitation. overall...

Abstract Entrainment into the stratocumulus‐topped boundary layer (STBL) is investigated by means of large‐eddy simulations. Set‐up numerical experiment based on research flight RF‐01 in DYCOMS‐II field campaign. We focus stability flow cloud‐top region known as Interface Layer (EIL). calculate local gradient Richardson number, Ri , at surface maximum static and material top STBL defined a threshold total water content. found that regions which updraughts impinge upon inversion diverge...

Abstract Moist anelastic and compressible numerical solutions to the planetary baroclinic instability climate benchmarks are compared. The obtained by applying a consistent framework for discrete integrations of various nonhydrostatic flow equations. extension benchmark is formulated as an analog dry case. Flow patterns, surface vertical vorticity pressure, total kinetic energy, power spectra, amount condensed water analyzed. extends study addressing long-term statistics idealized...

Abstract A pragmatic scale-adaptive turbulent kinetic energy (TKE) closure is proposed to simulate the dry convective boundary layer for a variety of horizontal grid resolutions: from 50 m, typical large-eddy simulation models that use three-dimensional turbulence parameterizations/closures, up 100 km, climate one-dimensional and convection parameterizations/closures. Since parameterizations/closures using TKE approach have been frequently used in these two asymptotic limits, simple method...

Abstract This study addresses key aspects of shallow moist convection, as simulated by a multiplume eddy-diffusivity/mass-flux (EDMF) model. Two factors suggested in the literature to be essential for development convective plumes are investigated: surface conditions and lateral entrainment. The model consistently decomposes subgrid vertical mixing into nonconvective environment. modeled convection shows low sensitivity plume area. results indicate that subcloud layer is controlled both...

Abstract. Global Navigation Satellite System radio occultation (GNSS-RO) and microwave radiometry (MWR) are two of the most impactful spaceborne remote sensing techniques for numerical weather prediction (NWP). These provide complementary information about atmospheric temperature water vapor structure. GNSS-RO provides high vertical resolution measurements with cloud penetration capability, but moisture coupled in retrieval process their separation requires use a priori or auxiliary...

Abstract When daytime tropical convection develops away from mesoscale disturbances, it typically transitions gradually dry to shallow deep on hourly timescales. The transition is commonly associated with the formation of larger horizontal boundary‐layer structures and an increasing level cloud organization aloft. This study demonstrates that a spectral analysis resolved high‐resolution sub‐cloud flow features allows for robust identification dominant length scales quantification their...

Abstract The key assumption underlying convection parameterizations is that rising plumes develop in a horizontally homogeneous environment. With this mind, we investigate the impact of environmental cloud layer heterogeneities on shallow using large‐eddy simulation applies driver‐piggybacker methodology. In approach, two independent sets thermodynamic variables (primary and secondary) are driven by one dynamics (coupled with driver) to remove internal variability dynamical system...

Abstract The role of nonlocal transport on the development and maintenance marine stratocumulus (Sc) clouds in coarse-resolution models is investigated, with a special emphasis downdraft contribution. A new parameterization cloud-top-triggered downdrafts proposed validated against large-eddy simulation (LES) for two Sc cases. applied mass-flux scheme part stochastic multiplume eddy-diffusivity/mass-flux (EDMF) framework decomposing turbulent into local contributions. complementary...

Abstract A systematic underestimation of subtropical planetary boundary layer (PBL) stratocumulus clouds by the GEOS model has been significantly improved a new eddy-diffusivity/mass-flux (EDMF) parameterization. The EDMF parameterization represents subgrid-scale transport in dry and moist parts PBL unified manner it combines an adjusted eddy-diffusivity scheme from with stochastic multiplume mass-flux model. version is first compared against CONTROL single-column (SCM) framework for two...

Abstract Modern general circulation models continue to require parameterizations of subgrid transport due planetary boundary layer (PBL) turbulence and convection. Some schemes that unify these processes rely on assumed joint probability distributions vertical velocity moist conserved thermodynamic variables predict the subgrid-scale contribution mean state atmosphere. The multivariate double-Gaussian mixture has been proposed as an appropriate model for PBL shallow convection, but it is...

Abstract Idealized large-eddy simulation (LES) is a basic tool for studying three-dimensional turbulence in the planetary boundary layer. LES capable of providing benchmark solutions parameterization development efforts. However, real small-scale atmospheric flows develop heterogeneous and transient environments with locally varying vertical motions inherent to open multiscale interactive dynamical systems. These variations are often too subtle detect them by state-of-the-art remote situ...

Abstract. Differential absorption radar (DAR) near the 183 GHz water vapor line is an emerging measurement technique for humidity profiling inside of clouds and precipitation with high vertical resolution, as well measuring integrated (IWV) in clear-air regions. For transmit frequencies on flank away from highly attenuating center, DAR system becomes most sensitive to planetary boundary layer (PBL), which a region atmosphere that poorly resolved by existing spaceborne temperature...

Abstract This paper discusses the incorporation of phase changes water substance that accompany moist atmospheric flows into all-scale model based on soundproof equations. A specific issue involves developing a theoretical basis and practical implementation to include pressure perturbations associated with circulations, from small scale global, representations thermodynamics. In small-scale modeling using equations, are obtained elliptic solver typically excluded argues in larger-scale...

The modular structure of the boundary layer and convection parameterizations in atmospheric models have long been affecting numerical representation subgrid-scale motions their mutual interactions. A promising alternative, eddy-diffusivity/mass-flux approach (EDMF), has potential for unifying existing formulations into a consistent scheme improving some long-standing issues. This study documents step towards developing such unified by implementing stochastic multi-plume EDMF Community...

A comparison between anelastic and compressible convection-permitting weather forecasts for the Alpine region is presented. This involves mesoscale simulation of a typical westerly flow accompanied by passage frontal systems as well intense airmass convection orographic convection. The limited-area model employing 2.2-km horizontal grid length driven time-dependent boundary conditions from coarse-resolution model. results obtained with versions show good agreement. Validations 10-m wind, 2-m...

Abstract. Daytime clear-sky total column water vapour (TCWV) is commonly retrieved from visible and shortwave infrared reflectance (VSWIR) measurements, modern missions such as the upcoming Earth Surface Mineral Dust Source Investigation (EMIT) offer unprecedented horizontal resolution of order 30–80 m. We provide evidence that for convective planetary boundary layers (PBLs), spatial variability in TCWV corresponds to PBL vapour. Using an observing system simulation experiment (OSSE) applied...

Abstract A new version of the stochastic multiplume Jet Propulsion Laboratory Eddy‐Diffusivity/Mass‐Flux (JPL‐EDMF) parameterization which consistently couples simplified Khairoutdinov and Kogan (2000), https://doi.org/10.1175/1520-0493(2000)128<0229:ANCPPI>2.0.CO;2 , warm phase cloud microphysical with macrophysical subgrid scale dynamical processes is described. The combines EDMF approach an assumed shape a joint probability density function thermodynamic kinematic variables provide...