We examine the latest decadal predictions performed with the coupled model MPI‐ESM as part of the Coupled Model Intercomparison Project Phase 5 (CMIP5). We use ensembles of uninitialized and yearly ...initialized experiments to estimate the forecast skill for surface air temperature. Like for its precursor, the initialization of MPI‐ESM improves forecast skill for yearly and multi‐yearly means, predominately over the North Atlantic for all lead times. Over the tropical Pacific, negative skill scores reflect a systematic error in the initialization. We also examine the forecast skill of multi‐year seasonal means. Skill scores of winter means are predominantly positive over northern Europe. In contrast, summer to autumn means reveal positive skill scores over central and south‐eastern Europe. The skill scores of summer means are attributable to an observed pressure‐gradient response to the North Atlantic surface temperatures.
Key Points
We provide decadal prediction for IPCC AR5
For the first time multi‐year seasonal means are considered
Skill for summer in central Europe are associated with North Atlantic SST
Ensemble experiments are performed with five coupled atmosphere–ocean models to investigate the potential for initial-value climate forecasts on interannual to decadal time scales. Experiments are ...started from similar model-generated initial states, and common diagnostics of predictability are used. We find that variations in the ocean meridional overturning circulation (MOC) are potentially predictable on interannual to decadal time scales, a more consistent picture of the surface temperature impact of decadal variations in the MOC is now apparent, and variations of surface air temperatures in the North Atlantic Ocean are also potentially predictable on interannual to decadal time scales, albeit with potential skill levels that are less than those seen for MOC variations. This intercomparison represents a step forward in assessing the robustness of model estimates of potential skill and is a prerequisite for the development of any operational forecasting system.
The ICON Earth System Model Version 1.0 Jungclaus, J. H.; Lorenz, S. J.; Schmidt, H. ...
Journal of advances in modeling earth systems,
April 2022, 2022-04-00, 20220401, 2022-04-01, Letnik:
14, Številka:
4
Journal Article
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This work documents the ICON‐Earth System Model (ICON‐ESM V1.0), the first coupled model based on the ICON (ICOsahedral Non‐hydrostatic) framework with its unstructured, icosahedral grid concept. The ...ICON‐A atmosphere uses a nonhydrostatic dynamical core and the ocean model ICON‐O builds on the same ICON infrastructure, but applies the Boussinesq and hydrostatic approximation and includes a sea‐ice model. The ICON‐Land module provides a new framework for the modeling of land processes and the terrestrial carbon cycle. The oceanic carbon cycle and biogeochemistry are represented by the Hamburg Ocean Carbon Cycle module. We describe the tuning and spin‐up of a base‐line version at a resolution typical for models participating in the Coupled Model Intercomparison Project (CMIP). The performance of ICON‐ESM is assessed by means of a set of standard CMIP6 simulations. Achievements are well‐balanced top‐of‐atmosphere radiation, stable key climate quantities in the control simulation, and a good representation of the historical surface temperature evolution. The model has overall biases, which are comparable to those of other CMIP models, but ICON‐ESM performs less well than its predecessor, the Max Planck Institute Earth System Model. Problematic biases are diagnosed in ICON‐ESM in the vertical cloud distribution and the mean zonal wind field. In the ocean, sub‐surface temperature and salinity biases are of concern as is a too strong seasonal cycle of the sea‐ice cover in both hemispheres. ICON‐ESM V1.0 serves as a basis for further developments that will take advantage of ICON‐specific properties such as spatially varying resolution, and configurations at very high resolution.
Plain Language Summary
ICON‐ESM is a completely new coupled climate and earth system model that applies novel design principles and numerical techniques. The atmosphere model applies a non‐hydrostatic dynamical core, both atmosphere and ocean models apply unstructured meshes, and the model is adapted for high‐performance computing systems. This article describes how the component models for atmosphere, land, and ocean are coupled together and how we achieve a stable climate by setting certain tuning parameters and performing sensitivity experiments. We evaluate the performance of our new model by running a set of experiments under pre‐industrial and historical climate conditions as well as a set of idealized greenhouse‐gas‐increase experiments. These experiments were designed by the Coupled Model Intercomparison Project (CMIP) and allow us to compare the results to those from other CMIP models and the predecessor of our model, the Max Planck Institute for Meteorology Earth System Model. While we diagnose overall satisfactory performance, we find that ICON‐ESM features somewhat larger biases in several quantities compared to its predecessor at comparable grid resolution. We emphasize that the present configuration serves as a basis from where future development steps will open up new perspectives in earth system modeling.
Key Points
This work documents ICON‐ESM 1.0, the first version of a coupled model based on the ICON framework
Performance of ICON‐ESM is assessed by means of CMIP6 Diagnosis, Evaluation, and Characterization of Klima experiments at standard CMIP‐type resolution
ICON‐ESM reproduces the observed temperature evolution. Biases in clouds, winds, sea‐ice, and ocean properties are larger than in MPI‐ESM
Revelation 20:1–10 has been discussed and debated from the earliest of times within Christian circles. The question has always been whether Revelation 20 ‘occurs’ after the return of Jesus Christ or ...whether it is to be appreciated as having a unique contribution to the overall message of the Apocalypse addressing the present church age. The objective of this article is to argue for the coherent complex structure of the Apocalypse including Revelation 20:1–10. The method will be a study of the entire Apocalypse to demonstrate how it functions coherently within its genre. The goal is to argue for a meaningful appreciation of the unique contribution of Revelation 20:1–10 to the present eschatological context of the church within the overall theological thrust. The chances of this chapter succeeding the return of Jesus Christ depicted in Revelation 19, as some would argue, are very remote. Three major themes are given in these 10 verses which are covered within the overall body of the Apocalypse and find a climax in this important chapter.
The Paris Agreement calls for efforts to limit anthropogenic global warming to less than 1.5 °C above preindustrial levels. However, natural internal variability may exacerbate anthropogenic warming ...to produce temporary excursions above 1.5 °C. Such excursions would not necessarily exceed the Paris Agreement, but would provide a warning that the threshold is being approached. Here we develop a new capability to predict the probability that global temperature will exceed 1.5 °C above preindustrial levels in the coming 5 years. For the period 2017 to 2021 we predict a 38% and 10% chance, respectively, of monthly or yearly temperatures exceeding 1.5 °C, with virtually no chance of the 5‐year mean being above the threshold. Our forecasts will be updated annually to provide policy makers with advanced warning of the evolving probability and duration of future warming events.
Plain Language Summary
The Paris Agreement calls for efforts to limit human‐induced global warming to less than 1.5 °C above preindustrial levels. Observations of global mean temperature contain both human‐induced temperature change and superimposed natural variability. Natural variability may temporarily add to the underlying human‐induced warming, leading to observed temperatures that are higher than 1.5 °C for short‐term periods. This would not necessarily exceed the Paris agreement, which is usually interpreted to refer to long‐term averages, but would give an important indication that the threshold is being approached. If exceedance occurs, policy makers will require guidance regarding how long temperatures will remain above the threshold. Here we develop a new capability to predict the likelihood that global temperature will exceed 1.5 °C above preindustrial levels in the coming 5 years. We use decadal climate predictions that are regularly produced by several international climate prediction centers. Importantly, these predictions take into account the observed present day conditions since this is essential to predict the evolution of natural variability. For the period 2017 to 2021 we predict a 38% and 10% chance, respectively, of monthly or yearly temperatures exceeding 1.5 °C, with virtually no chance of the 5‐year mean being above the threshold. We will update our forecasts every year to provide policy makers with advanced warning of the evolving probability and duration of future warming events.
Key Points
Early temporary excursions above 1.5 °C would provide a warning that one of the Paris Agreement thresholds is being approached
Initialized climate predictions indicate a 38% (10%) chance of at least 1 month (year) exceeding 1.5 °C in the 5 year period 2017‐2021
Five‐year mean temperatures above 1.5 °C are extremely unlikely in this period
A multi-model ensemble of decadal prediction experiments, performed in the framework of the EU-funded COMBINE (Comprehensive Modelling of the Earth System for Better Climate Prediction and ...Projection) Project following the 5th Coupled Model Intercomparison Project protocol is examined. The ensemble combines a variety of dynamical models, initialization and perturbation strategies, as well as data assimilation products employed to constrain the initial state of the system. Taking advantage of the multi-model approach, several aspects of decadal climate predictions are assessed, including predictive skill, impact of the initialization strategy and the level of uncertainty characterizing the predicted fluctuations of key climate variables. The present analysis adds to the growing evidence that the current generation of climate models adequately initialized have significant skill in predicting years ahead not only the anthropogenic warming but also part of the internal variability of the climate system. An important finding is that the multi-model ensemble mean does generally outperform the individual forecasts, a well-documented result for seasonal forecasting, supporting the need to extend the multi-model framework to real-time decadal predictions in order to maximize the predictive capabilities of currently available decadal forecast systems. The multi-model perspective did also allow a more robust assessment of the impact of the initialization strategy on the quality of decadal predictions, providing hints of an improved forecast skill under full-value (with respect to anomaly) initialization in the near-term range, over the Indo-Pacific equatorial region. Finally, the consistency across the different model predictions was assessed. Specifically, different systems reveal a general agreement in predicting the near-term evolution of surface temperatures, displaying positive correlations between different decadal hindcasts over most of the global domain.
TCH346 exerts antiapoptotic effects by binding to glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and blocking the apoptotic pathway in which GAPDH is involved. Apoptosis is considered to be a key ...pathogenic mechanism in neurodegenerative diseases including ALS.
Patients were randomly assigned in a double-blind fashion to receive either placebo or one of four doses of TCH346 (1.0, 2.5, 7.5, or 15 mg/day) administered orally once daily for at least 24 weeks. The primary outcome measure was the rate of change in the revised ALS functional rating scale (ALSFRS-R). The trial design included a 16-week lead-in phase to determine each patient's rate of disease progression. The between treatment comparison was adjusted for the individual pretreatment rates of progression. The study was powered to detect a 25% reduction in the rate of decline of the ALSFRS-R as compared with placebo. Secondary outcome measures included survival, pulmonary function, and manual muscle testing (MMT).
Five hundred ninety-one patients were enrolled at 42 sites in Europe and North America. There were no differences in baseline variables. There were no significant differences between placebo and active treatment groups in the mean rate of decline of the ALSFRS-R or in the secondary outcome measures (survival, pulmonary function, and MMT).
The trial revealed no evidence of a beneficial effect of TCH346 on disease progression in patients with ALS.
•Experiments on a circular track with 20+ vehicles show stop-and-go waves emerge.•Control of an autonomous vehicle can dampen stop-and-go waves in field experiments.•Control of one autonomous vehicle ...reduces total traffic fuel consumption.•Mobile traffic control is possible when a small fraction of vehicles are automated.
Traffic waves are phenomena that emerge when the vehicular density exceeds a critical threshold. Considering the presence of increasingly automated vehicles in the traffic stream, a number of research activities have focused on the influence of automated vehicles on the bulk traffic flow. In the present article, we demonstrate experimentally that intelligent control of an autonomous vehicle is able to dampen stop-and-go waves that can arise even in the absence of geometric or lane changing triggers. Precisely, our experiments on a circular track with more than 20 vehicles show that traffic waves emerge consistently, and that they can be dampened by controlling the velocity of a single vehicle in the flow. We compare metrics for velocity, braking events, and fuel economy across experiments. These experimental findings suggest a paradigm shift in traffic management: flow control will be possible via a few mobile actuators (less than 5%) long before a majority of vehicles have autonomous capabilities.
There is growing interest in the field of decadal climate prediction, supported by observational evidence of natural decadal climate variations with significant regional impacts, and evidence of ...potential skill from idealized predictability studies and pioneering attempts at predictions obtained by initializing climate models with observations. A synthesis of the current state of observed decadal climate variability (DCV) characteristics and some examples of DCV impacts on climate on land is given. Aspects of DCV arising either from internal climate variability or from natural external forcing were described. The potential predictability from these sources, and also from the influence of anthropogenic external forcing is considered. As this new area of climate science is at an early stage, a number of significant challenges need to be addressed if practical prediction systems capable of producing credible projections at regional scales for use by scientists, stakeholders and planners are to be provided and summary of these challenges is given.
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