41 research outputs found
Surface warming and wetting due to methane’s long-wave radiative effects muted by short-wave absorption
Although greenhouse gases absorb primarily long-wave radiation, they also absorb short-wave radiation. Recent studies have highlighted the importance of methane short-wave absorption, which enhances its stratospherically adjusted radiative forcing by up to ~ 15%. The corresponding climate impacts, however, have been only indirectly evaluated and thus remain largely unquantified. Here we present a systematic, unambiguous analysis using one model and separate simulations with and without methane short-wave absorption. We find that methane short-wave absorption counteracts ~30% of the surface warming associated with its long-wave radiative effects. An even larger impact occurs for precipitation as methane short-wave absorption offsets ~60% of the precipitation increase relative to its long-wave radiative effects. The methane short-wave-induced cooling is due largely to cloud rapid adjustments, including increased low-level clouds, which enhance the reflection of incoming short-wave radiation, and decreased high-level clouds, which enhance outgoing long-wave radiation. The cloud responses, in turn, are related to the profile of atmospheric solar heating and corresponding changes in temperature and relative humidity. Despite our findings, methane remains a potent contributor to global warming, and efforts to reduce methane emissions are vital for keeping global warming well below 2 °C above preindustrial values
Worldwide impact of aerosol’s time scale on the predicted long-term concentrating solar power potential
Evaluating the performance and energy efficiency of the COSMO-ART model system
In this paper we investigate the energy footprint and performance profiling of COSMO-ART on various HPC platforms. This model is an extension of the operational weather forecast model of the German weather service (DWD), developed for the evaluation of the interactions of reactive gases and aerosol particles with the state of atmosphere at the regional scale. Different measurement devices and energy-aware techniques are described to evaluate both time and energy to solution of the considered application and to gain detailed insights into power and performance requirements. Our motivation is to improve corresponding code sections to sustain performance while minimizing energy-to-solution. This preliminary work sets the basis for subsequent studies to tackle challenges related to energy efficient high performance computing in the framework of the Exa2Green project (EU FET Project, http://​exa2green.​eu/​)
Subcutaneous implantable cardioverter defibrillator eligibility according to a novel automated screening tool and agreement with the standard manual electrocardiographic morphology tool
Purpose: Since subcutaneous implantable cardioverter defibrillator (S-ICD) introduction, the pre-implant screening based on a dedicated manual ECG tool (MST) was required to assure adequate sensing by the S-ICD. A novel automated screening tool (AST) has been recently developed. We assessed and compared the pass rate with AST and MST, and we measured the agreement between screening tools. Methods: Three electrodes were positioned at locations mimicking the placement of the S-ICD, and ECG recordings were collected in the supine and standing postures at rest. The three sensing vectors were analyzed with the MST and the AST. Eligibility was defined by the presence of at least one or two appropriate vectors in both postures. Results: A total of 235 patients with an indication to ICD and no need for permanent pacing were enrolled. At least one suitable vector was identified in 214 (91%) patients with MST and 221 (94%) patients with AST (p = 0.219). At least two vectors were appropriate in 162 (69%) patients with MST and 187 (80%) patients with AST (p = 0.008). Overall, out of 1587 ECG analyzed, 1035 (65%) qualifying leads were identified with MST and 1111 (70%) with AST (p = 0.004). The agreement between the results of MST and AST ECG analysis was moderate (Kappa = 0.570; standard error = 0.022; CI = 0.526–0.613). The results were consistent regardless of the underlying cardiomyopathy. The most frequent reason for screening failure with MST was a high-amplitude T-wave (31% of failures). With AST, 23% of recordings that failed with MST for high-amplitude T-wave were classified as acceptable. Conclusion: The AST is associated with higher pass rate than the standard MST. It seems more tolerant of high-amplitude T-waves. Consequently, the agreement between MST and AST findings was only moderate