Prépublication
· 2026 arXiv
EN
Rainfall forecasts over the Western Himalaya remain poor, and the relative contributions of the cumulus and microphysics parameterizations to that error are not well constrained.
Satyam Kumar, Akshay Sunil et al.
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Prépublication
· 2026 arXiv
EN
We present HiRO-ACEv2 (High Resolution Output Ai2 Climate Emulator), a two-stage framework for AI emulation of the 3~km resolution X-SHiELD global storm-resolving model (GSRM), and highlight its ability to generate large ensembles of data for studying the char...
Anna Kwa, W. Andre Perkins et al.
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Prépublication
· 2026 arXiv
EN
The Hybrid forecast covariance model is an operationally successful way to build a background error covariance matrix. It is constructed as a weighted sum, with scalar weights, of the climatological covariance matrix and a localized ensemble covariance matrix,...
Francesco Sardelli, Craig H. Bishop
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Prépublication
· 2026 arXiv
EN
Global reanalyses are too coarse to resolve the convective systems that produce most West African monsoon rainfall. In this work, we use U-Net based architectures to downscale daily ERA5 fields (0.25°) to IMERG V07 satellite precipitation (0.1°) over West Afri...
David Sagna, Redouane Lguensat et al.
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Prépublication
· 2026 arXiv
EN
A potentially super El Niño is forecasted in 2026, raising the need to anticipate land carbon-cycle risks before its impacts unfold. We develop a prospective early-warning framework that uses dynamic global vegetation models driven by an ensemble of ECMWF seas...
Xiaomeng Du, Runda Jiang et al.
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Prépublication
· 2026 arXiv
EN
This work investigates the incidence of rapid ice-loss events in the Arctic, in which a substantial fraction of September sea-ice is lost in only a few years. Such events are seen to occur in climate model simulations forced with increasing greenhouse gas conc...
Matthew Patterson, Ioana Colfescu et al.
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Prépublication
· 2026 arXiv
EN
Ensemble forecasts from the ECMWF's Integrated Forecasting System (IFS) and the Artificial Intelligence Forecasting System (AIFS-ENS) are compared using a multi-dimensional evaluation framework. Within this framework, the uncertainty is interpreted as the line...
Martin Bonte, Stéphane Vannitsem
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Prépublication
· 2026 arXiv
EN
A long-standing challenge in climate science since the Charney Report in 1979 is to determine how much the Earth's climate warms in response to a unit external energy input at the top of the atmosphere (TOA). In this study, we show from first principles that t...
Ming Cai, Jie Sun et al.
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Prépublication
· 2026 arXiv
EN
The notion of tipping points and related terminology have so far had inconsistent and sometimes confusing definitions in both scientific and popular literature. While it is difficult for the scientific community to align popular usage of the term tipping point...
Niklas Boers, Robert E. Kopp et al.
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Prépublication
· 2026 arXiv
EN
Currently available methods for processing atmospheric wave disturbances are often based on integral wavelet transform techniques, which efficiently estimate spectral data but are fundamentally limited by the uncertainty principle. To address this limitation,...
Yuriy Klymenko, Alla Fedorenko et al.
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Prépublication
· 2026 arXiv
EN
In this report, 15 variants of nine parametric models for non-directional ocean wave spectra are reviewed. They are compared against observation-based spectra created by taking spectra measured by moored buoys, binning by wind speed, and averaging. Surface Sto...
W. Erick Rogers, Yalin Fan et al.
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Prépublication
· 2026 arXiv
EN
Legacy Fortran physics packages in atmospheric models such as CESM, WRF, and E3SM pose a barrier to GPU modernization, while manual porting requires accelerator-programming expertise. We present LAFT (LLM-Assisted Fortran Translation), an agentic framework for...
Iris Linck, John Dennis et al.
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