Characteristics of mesoscale convective systems over China and its vicinity using geostationary satellite FY2 ABSTRACT This study investigates mesoscale convective systems (MCSs) over China and its vicinity during the boreal warm season (May-August) from 2005 to 2012 based on data from the geostationary satellite Fengyun 2 (FY2) series. The authors classified and analyzed the quasi-circular and elongated MCSs on both large and small scales, including mesoscale convective complexes (MCCs), persistent elongated convective systems (PECSs), meso-b circular convective systems (MbCCSs), meso-b elongated convective system (MbECSs), and two additional types named small meso-b circular convective systems (SMbCCSs) and small meso-b elongated convective systems (SMbECSs). Results show that nearly 80% of the 8696 MCSs identified in this study fall into the elongated categories. Overall, MCSs occur mainly at three zonal bands with average latitudes around 208, 308, and 508N. The frequency of MCSs occurrences is maximized at the zonal band around 208N and decreases with increase in latitude. During the eight warm seasons, the period of peak systems occurrences is in July, followed decreasingly by June, August, and May. Meanwhile, from May to August three kinds of monthly variations are observed, which are clear northward migration, rapid increase, and persistent high frequency of MCS occurrences. Compared to MCSs in the United States, the four types of MCSs (MCCs, PECSs, MbCCSs, and MbECSs) are relatively smaller both in size and eccentricity but exhibit nearly equal life spans. Moreover, MCSs in both countries share similar positive correlations between their duration and maximum extent. Additionally, the diurnal cycles of MCSs in both countries are similar (local time) regarding the three stages of initiation, maturation, and termination.

Here we demonstrate flexible polymer solar cells with a record high power conversion efficiency of 8.7% and a very high specific power of 400 W kg−1, by depositing a physical blend of a conjugated semiconducting polymer and a fullerene derivative on a highly flexible polyethylene terephthalate (PET) substrate.

Flexible supercapacitors, which can sustain large deformations while maintaining normal functions and reliability, are playing an increasingly important role in portable electronics. Here we report the preparation of a three-dimensional α-Fe 2 O 3 /carbon nanotube (CNT@Fe 2 O 3 ) sponge electrode with a porous hierarchical structure, consisting of a compressible, conductive CNT network, coated with a layer of Fe 2 O 3 nanohorns. The specific capacitance of these hybrid sponges has been significantly improved to above 300 F/g, while the equivalent series resistance remains at about 1.5 Ω. The highly deformed CNT@Fe 2 O 3 sponge retains more than 90 % of the original specific capacitance under a compressive strain of 70% (corresponding to a volume reduction of 70%). The hybrid sponge still works stably and sustains similar specific capacitance as initial value even after 1000 compression cycles at a strain of 50%. The outstanding properties of this hybrid sponge make it a highly promising candidate for flexible energy devices.

The U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) user facility recently initiated the Large-Eddy Simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) activity focused on shallow convection at ARM’s Southern Great Plains (SGP) atmospheric observatory in Oklahoma. LASSO is designed to overcome an oft-shared difficulty of bridging the gap from point-based measurements to scales relevant for model parameterization development, and it provides an approach to add value to observations through modeling. LASSO is envisioned to be useful to modelers, theoreticians, and observationalists needing information relevant to cloud processes. LASSO does so by combining a suite of observations, LES inputs and outputs, diagnostics, and skill scores into data bundles that are freely available, and by simplifying user access to the data to speed scientific inquiry. The combination of relevant observations with observationally constrained LES output provides detail that gives context to the observations by showing physically consistent connections between processes based on the simulated state. A unique approach for LASSO is the generation of a library of cases for days with shallow convection combined with an ensemble of LES for each case. The library enables researchers to move beyond the single-case-study approach typical of LES research. The ensemble members are produced using a selection of different large-scale forcing sources and spatial scales. Since large-scale forcing is one of the most uncertain aspects of generating the LES, the ensemble informs users about potential uncertainty for each date and increases the probability of having an accurate forcing for each case.