Preprints
Filtering by Subject: Meteorology
A multi-indicator framework for assessing the likelihood of ENSO impacts across southern Africa
Published: 2026-07-02
Subjects: Atmospheric Sciences, Climate, Meteorology, Oceanography and Atmospheric Sciences and Meteorology
The El Niño-Southern Oscillation (ENSO) is the dominant source of seasonal predictability for southern Africa, yet operational guidance rarely conveys which agriculturally relevant variables it can skillfully predict, or where ENSO impacts are most likely. We present an operational analysis framework that converts an ENSO state, classified by phase and strength, into gridded, analogue-composite [...]
A State-dependent Error Covariance Model of Surface Atmospheric Forcings over the Arctic Sea Ice
Published: 2026-07-01
Subjects: Atmospheric Sciences, Meteorology, Oceanography, Other Oceanography and Atmospheric Sciences and Meteorology
This paper presents a state-dependent error covariance model of surface atmospheric forcings over Arctic sea ice for constraining atmospheric influences on short-range sea ice forecast errors. Atmospheric influences are argued to be a dominant source of sea ice forecast errors at shorter lead times and thus need to be properly accounted for in generating ensemble sea ice forecasts relevant for [...]
Resolving microscale surface temperature variability during a heatwave using a dense sensor network
Published: 2026-06-29
Subjects: Climate, Environmental Monitoring, Environmental Sciences, Meteorology, Oceanography and Atmospheric Sciences and Meteorology
High-resolution observations of near-surface temperature variability are essential for understanding heat exposure during extreme weather events, yet are rarely available from dense, regularly spaced in situ measurement grids, with most existing observations derived from unevenly distributed sensor networks. Here, we analyse temperature measurements derived from a dense network of over 3,000 [...]
Measurement and Tracking of Blowing and Falling Snow Particles Using an Automotive 1550 nm LiDAR
Published: 2026-06-26
Subjects: Atmospheric Sciences, Fresh Water Studies, Glaciology, Hydrology, Meteorology
The prevalence and affordability of fast-scanning commercially available LiDARs are increasing due to the rapid expansion of the autonomous vehicle industry. These LiDAR units can provide >1 Hz measurements of millions of laser reflections at ranges of hundreds of meters with high precision. In this study we investigate the often overlooked 1550 nm wavelength LiDAR for measurements of airborne [...]
Dress Rehearsal: 2023 El Niño Anticipatory Action Somalia, in the Shadow of 1997
Published: 2026-06-10
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Environmental Studies, Human Geography, Meteorology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Other Geography, Physical and Environmental Geography
In 2023 Somalia saw the largest-ever scale of anticipatory action (AA) linked to a seasonal forecast. $24m was spent on preparedness and early response, based on forecasted flooding driven by El Niño and a positiveIn 2023 Somalia saw the largest-ever scale of anticipatory action (AA) linked to a seasonal forecast. $24m was spent on preparedness and early response, based on forecasted flooding [...]
ENSO Modulation of the Amazonian Low-Level Jet: More Moisture, Less Rain, and the Role of Land Surface Reception
Published: 2026-05-30
Subjects: Climate, Hydrology, Meteorology
The Amazonian Low-Level Jet (ALLJ) carries moisture from the tropical Atlantic coast into the basin interior, sustaining wet-season convection. Here we analyze 45 years of ERA5 reanalysis (1979–2023), 44 years of CHIRPS precipitation (1981–2024), GRACE terrestrial water storage (2002–2025), and SMAP root-zone soil moisture (2015–2024) to determine how ENSO modulates this transport pathway and its [...]
Analysis of sub-regional climates in the European Alps based on the EEAR-Clim observational dataset
Published: 2026-05-22
Subjects: Atmospheric Sciences, Climate, Meteorology
The European Alps exhibit a complex geomorphology and undergo the influences of different climate regimes, resulting in high spatial variability of climatic variables and their changes. To provide a detailed analysis of climate regions and climatic changes occurring at a sub-regional scale during the 1961-2020 period, we exploited an updated regionalization of the European Alps that benefits from [...]
First Observational Evidence That Biological Giant CCN Control Urban Rainfall Character: A Natural Experiment from Islamabad's Paper Mulberry Removal
Published: 2026-05-22
Subjects: Atmospheric Sciences, Earth Sciences, Hydrology, Meteorology
Modeling studies predict that biological aerosol, specifically pollen acting as giant cloud condensation nuclei (GCCN), can modify precipitation character by initiating collision-coalescence and warm rain in shallow cloud (Steiner et al., 2015; Wozniak et al., 2018; Paukert et al., 2025). No observational study has tested this prediction. We exploit a natural experiment, the removal of ~29,000 [...]
Deep learning identification of SST teleconnections driving early-winter North Atlantic climate
Published: 2026-05-22
Subjects: Atmospheric Sciences, Climate, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Seasonal predictability over the North Atlantic-European (NAE) sector is strongly modulated by the background climate state, particularly in early winter. In this season, different ENSO teleconnections have been reported before and after the 1990s. However, these studies rely on linear analysis, and the reasons for this lack of stationarity and its implications for seasonal forecasting have not [...]
Spatiotemporal evolution of temperature extremes across India’s agro-climatic zones (1951–2025)
Published: 2026-04-11
Subjects: Atmospheric Sciences, Climate, Meteorology, Oceanography
Long-term changes in temperature extremes are a robust signature of anthropogenic climate change, yet their spatial structure across India’s agro-climatic zones (ACZs) remains insufficiently resolved at policy scales. Here, we quantify changes in temperature extremes across 14 mainland ACZs during 1951–2025 using the India Meteorological Department 1°×1° gridded daily dataset. We compute 22 [...]
Forward-Only Temporal-Coherence Occupancy Regimes in Atlantic Tropical Cyclone Intensity Evolution (1851–2024)
Published: 2026-04-01
Subjects: Atmospheric Sciences, Meteorology, Physical Sciences and Mathematics
Rapid intensification (RI) remains one of the most consequential and difficult-to-characterize aspects of tropical cyclone intensity evolution, commonly defined as an increase in maximum sustained wind speed of at least 30 kt within 24 h (Kaplan and DeMaria 2003; Kaplan et al. 2010; DeMaria et al. 2021). This study asks whether Atlantic best-track intensity records contain forward-detectable [...]
Do Less Predictable Tropical Cyclones Induce Larger Damages?
Published: 2026-03-17
Subjects: Atmospheric Sciences, Hydrology, Meteorology, Statistical Models
Tropical cyclones (TCs) cause substantial disaster losses worldwide. Forecast skill for TC track and intensity has been improved by enhanced observations, high-resolution numerical models, advanced data assimilation methods, and applications of machine-learning methods. Yet these improvements have not consistently translated into reduced losses, in part because disaster outcomes depend on many [...]
The Response of Onset and Withdrawal of the Indian Summer Monsoon to Volcanic Aerosols
Published: 2026-03-04
Subjects: Atmospheric Sciences, Climate, Meteorology
Large volcanic eruptions are a source of climate variability, affecting the seasonal mean precipitation of the Indian summer monsoon. However, the extent to which changes in seasonal precipitation can be attributed to variations in monsoon length vs. monsoon intensity has remained unclear. Using large ensemble simulations of idealised volcanic eruptions at varying latitudes, we find that the [...]
Visualizing Pyroclimotology
Published: 2026-02-25
Subjects: Climate, Environmental Education, Meteorology, Natural Resources Management and Policy, Physical and Environmental Geography, Remote Sensing
Background: Wildland fire activity often demonstrates distinct seasonality adhering to the alignment of climatologically favorable fuels, weather, and ignitions for wildfire or prescribed burning. Improved characterization of conditions that increase fire ignition probabilities, extreme fire behavior, and beneficial fire potential would enhance our understanding of fire regimes and provide [...]
Quantifying the Causal Strength of Compound Drought–Heatwaves: Implications for Fire Events and Cropland Productivity
Published: 2026-02-21
Subjects: Atmospheric Sciences, Climate, Meteorology
Compound drought and heatwave (CDHW) events represent one of the most disruptive forms of climate extremes, as the simultaneous occurrence of dry and hot conditions signifies their impacts far beyond those of individual events. Yet, despite their increasing significance, the causal influence of CDHW frequency and severity on fire activity and crop yield variability remains poorly quantified, [...]