TY - JOUR A1 - Leung, Tsz Yan A1 - Leutbecher, Martin A1 - Reich, Sebastian A1 - Shepherd, Theodore G. T1 - Atmospheric Predictability: Revisiting the Inherent Finite-Time Barrier JF - Journal of the atmospheric sciences N2 - The accepted idea that there exists an inherent finite-time barrier in deterministically predicting atmospheric flows originates from Edward N. Lorenz’s 1969 work based on two-dimensional (2D) turbulence. Yet, known analytic results on the 2D Navier–Stokes (N-S) equations suggest that one can skillfully predict the 2D N-S system indefinitely far ahead should the initial-condition error become sufficiently small, thereby presenting a potential conflict with Lorenz’s theory. Aided by numerical simulations, the present work reexamines Lorenz’s model and reviews both sides of the argument, paying particular attention to the roles played by the slope of the kinetic energy spectrum. It is found that when this slope is shallower than −3, the Lipschitz continuity of analytic solutions (with respect to initial conditions) breaks down as the model resolution increases, unless the viscous range of the real system is resolved—which remains practically impossible. This breakdown leads to the inherent finite-time limit. If, on the other hand, the spectral slope is steeper than −3, then the breakdown does not occur. In this way, the apparent contradiction between the analytic results and Lorenz’s theory is reconciled. KW - Atmosphere KW - Turbulence KW - Error analysis KW - Spectral analysis KW - models KW - distribution KW - Numerical weather prediction KW - forecasting Y1 - 2019 U6 - https://doi.org/10.1175/JAS-D-19-0057.1 SN - 0022-4928 SN - 1520-0469 VL - 76 IS - 12 SP - 3883 EP - 3892 PB - American Meteorological Soc. CY - Boston ER - TY - GEN A1 - Ayzel, Georgy A1 - Varentsova, Natalia A1 - Erina, Oxana A1 - Sokolov, Dmitriy A1 - Kurochkina, Liubov A1 - Moreydo, Vsevolod T1 - OpenForecast BT - The First Open-Source Operational Runoff Forecasting System in Russia T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The development and deployment of new operational runoff forecasting systems are a strong focus of the scientific community due to the crucial importance of reliable and timely runoff predictions for early warnings of floods and flashfloods for local businesses and communities. OpenForecast, the first operational runoff forecasting system in Russia, open for public use, is presented in this study. We developed OpenForecast based only on open-source software and data-GR4J hydrological model, ERA-Interim meteorological reanalysis, and ICON deterministic short-range meteorological forecasts. Daily forecasts were generated for two basins in the European part of Russia. Simulation results showed a limited efficiency in reproducing the spring flood of 2019. Although the simulations managed to capture the timing of flood peaks, they failed in estimating flood volume. However, further implementation of the parsimonious data assimilation technique significantly alleviates simulation errors. The revealed limitations of the proposed operational runoff forecasting system provided a foundation to outline its further development and improvement. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1338 KW - OpenForecast KW - open KW - operational service KW - runoff KW - forecasting KW - Russia Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-473295 SN - 1866-8372 IS - 1338 ER - TY - JOUR A1 - Ayzel, Georgy A1 - Varentsova, Natalia A1 - Erina, Oxana A1 - Sokolov, Dmitriy A1 - Kurochkina, Liubov A1 - Moreydo, Vsevolod T1 - OpenForecast BT - The First Open-Source Operational Runoff Forecasting System in Russia JF - Water : Molecular Diversity Preservation International N2 - The development and deployment of new operational runoff forecasting systems are a strong focus of the scientific community due to the crucial importance of reliable and timely runoff predictions for early warnings of floods and flashfloods for local businesses and communities. OpenForecast, the first operational runoff forecasting system in Russia, open for public use, is presented in this study. We developed OpenForecast based only on open-source software and data-GR4J hydrological model, ERA-Interim meteorological reanalysis, and ICON deterministic short-range meteorological forecasts. Daily forecasts were generated for two basins in the European part of Russia. Simulation results showed a limited efficiency in reproducing the spring flood of 2019. Although the simulations managed to capture the timing of flood peaks, they failed in estimating flood volume. However, further implementation of the parsimonious data assimilation technique significantly alleviates simulation errors. The revealed limitations of the proposed operational runoff forecasting system provided a foundation to outline its further development and improvement. KW - OpenForecast KW - open KW - operational service KW - runoff KW - forecasting KW - Russia Y1 - 2019 U6 - https://doi.org/10.3390/w11081546 SN - 2073-4441 VL - 11 IS - 8 PB - MDPI CY - Basel ER - TY - JOUR A1 - Pennekamp, Frank A1 - Iles, Alison C. A1 - Garland, Joshua A1 - Brennan, Georgina A1 - Brose, Ulrich A1 - Gaedke, Ursula A1 - Jacob, Ute A1 - Kratina, Pavel A1 - Matthews, Blake A1 - Munch, Stephan A1 - Novak, Mark A1 - Palamara, Gian Marco A1 - Rall, Bjorn C. A1 - Rosenbaum, Benjamin A1 - Tabi, Andrea A1 - Ward, Colette A1 - Williams, Richard A1 - Ye, Hao A1 - Petchey, Owen L. T1 - The intrinsic predictability of ecological time series and its potential to guide forecasting JF - Ecological monographs : a publication of the Ecological Society of America. KW - empirical dynamic modelling KW - forecasting KW - information theory KW - permutation entropy KW - population dynamics KW - time series analysis Y1 - 2019 U6 - https://doi.org/10.1002/ecm.1359 SN - 0012-9615 SN - 1557-7015 VL - 89 IS - 2 PB - Wiley CY - Hoboken ER -