Advances in high‐performance computing have enabled large‐eddy simulations (LES) of turbulence, convection, and clouds. However, their potential to improve parameterizations in global climate models (GCMs) is only beginning to be harnessed, with relatively few canonical LES available so far. The purpose of this paper is to begin creating a public LES library that expands the training data available for calibrating and evaluating GCM parameterizations. To do so, we use an experimental setup in which LES are driven by large‐scale forcings from GCMs, which in principle can be used at any location, any time of year, and in any climate state. We use this setup to create a library of LES of clouds across the tropics and subtropics, in the present and in a warmer climate, with a focus on the transition from stratocumulus to shallow cumulus over the East Pacific. The LES results are relatively insensitive to the choice of host GCM driving the LES. Driven with large‐scale forcing under global warming, the LES simulate a positive but weak shortwave cloud feedback, adding to the accumulating evidence that low clouds amplify global warming.

Abstract. We introduce ClimateMachine, a new open-source atmosphere modeling framework which uses the Julia language and is designed to be scalable on central processing units (CPUs) and graphics processing units (GPUs). ClimateMachine uses a common framework both for coarser-resolution global simulations and for high-resolution, limited-area large-eddy simulations (LESs). Here, we demonstrate the LES configuration of the atmosphere model in canonical benchmark cases and atmospheric flows using a total energy-conserving nodal discontinuous Galerkin (DG) discretization of the governing equations. Resolution dependence, conservation characteristics, and scaling metrics are examined in comparison with existing LES codes. They demonstrate the utility of ClimateMachine as a modeling tool for limited-area LES flow configurations.

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A network of acceleration and displacement sensors installed in the Christchurch Women's Hospital (CWH) in July 2011 captured an extensive range of earthquake signals, allowing for a unique opportunity to analyze the performance of the New Zealand South Island's only base-isolated structure. Key characteristics of a range of earthquake signals, including frequency spectra and response patterns, are identified, with particular focus on the swarm of earthquakes on 23 December 2011, including four earthquake events greater than magnitude 5.0 on the Richter scale. The findings indicate that the response of the isolators and the superstructure was essentially elastic for the events analyzed during this period. Accelerations measured above and below the isolators were similar, indicating that the behavior of the devices resembled that of rigid blocks. No significant rocking or torsional motion of the building was observed.

A semi-empirical model is presented that describes the development of a fully developed turbulent boundary layer in the presence of surface roughness with length scale $k_{s}$ that varies with streamwise distance $x$. Interest is centred on flows for which all terms of the von Kármán integral relation, including the ratio of outer velocity to friction velocity $U_{\infty }^{+}\equiv U_{\infty }/u_{\unicode[STIX]{x1D70F}}$, are streamwise constant. For $Re_{x}$ assumed large, use is made of a simple log-wake model of the local turbulent mean-velocity profile that contains a standard mean-velocity correction for the asymptotic fully rough regime and with assumed constant parameter values. It is then shown that, for a general power-law external velocity variation $U_{\infty }\sim x^{m}$, all measures of the boundary-layer thickness must be proportional to $x$ and that the surface sand-grain roughness scale variation must be the linear form $k_{s}(x)=\unicode[STIX]{x1D6FC}x$, where $x$ is the distance from the boundary layer of zero thickness and $\unicode[STIX]{x1D6FC}$ is a dimensionless constant. This is shown to give a two-parameter $(m,\unicode[STIX]{x1D6FC})$ family of solutions, for which $U_{\infty }^{+}$ (or equivalently $C_{f}$) and boundary-layer thicknesses can be simply calculated. These correspond to perfectly self-similar boundary-layer growth in the streamwise direction with similarity variable $z/(\unicode[STIX]{x1D6FC}x)$, where $z$ is the wall-normal coordinate. Results from this model over a range of $\unicode[STIX]{x1D6FC}$ are discussed for several cases, including the zero-pressure-gradient ($m=0$) and sink-flow ($m=-1$) boundary layers. Trends observed in the model are supported by wall-modelled large-eddy simulation of the zero-pressure-gradient case for $Re_{x}$ in the range $10^{8}{-}10^{10}$ and for four values of $\unicode[STIX]{x1D6FC}$. Linear streamwise growth of the displacement, momentum and nominal boundary-layer thicknesses is confirmed, while, for each $\unicode[STIX]{x1D6FC}$, the mean-velocity profiles and streamwise turbulent variances are found to collapse reasonably well onto $z/(\unicode[STIX]{x1D6FC}x)$. For given $\unicode[STIX]{x1D6FC}$, calculations of $U_{\infty }^{+}$ obtained from large-eddy simulations are streamwise constant and independent of $Re_{x}$ when this is large. The present results suggest that, in the sense that $U_{\infty }^{+}(\unicode[STIX]{x1D6FC},m)$ is constant, these flows can be interpreted as the fully rough limit for boundary layers in the presence of small-scale linear roughness.