Preprints
Filtering by Subject: Atmospheric Sciences
Changes to the Madden-Julian Oscillation with Surface Temperature Warming in Aquaplanet Simulations
Published: 2026-09-23
Subjects: Atmospheric Sciences, Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Interactions between waves and the mean-state in the tropics are of fundamental importance for reliable future projection of tropical waves and their impacts under anthropogenic climate change. The Madden-Julian Oscillation (MJO) is the dominant source of weather variability over many parts of the globe on intraseasonal timescales. In this study, we investigate the influence of mean-state changes [...]
Estimating Extreme Gusts via Optical Flow Tracking from Defoliated Tree Motion
Published: 2026-09-23
Subjects: Atmospheric Sciences, Meteorology
Peak 3-second gusts (s₃) during severe storms are critical drivers of wind damage, yet their fine-scale dynamics remain difficult to measure. Visual Anemometry (VA) unlocks the possibility of spatially dense wind speed estimates, yet its performance under extreme winds remains poorly understood. Here, we combine physics-based simulations of tree motion with Optical Flow Tracking Velocimetry [...]
Extreme Precipitation Indices Trends and Patterns in the Philippines
Published: 2026-09-20
Subjects: Atmospheric Sciences, Climate, Environmental Sciences, Meteorology
The Philippines experiences approximately 86% of its recorded disaster events from extreme precipitation, yet national-scale trend studies remain constrained by sparse station networks and narrow index coverage. This study mapped the spatial patterns and long-term trends of 12 extreme precipitation indices across the Philippine archipelago using 45 years of daily gridded precipitation data from [...]
Quantification of Power Plant NOx Emissions: A Reference for Diurnal and Seasonal Accuracy of TEMPO
Published: 2026-09-19
Subjects: Atmospheric Sciences, Remote Sensing
Satellite observations of NO2 from geostationary orbit provide an opportunity to study daytime emissions with hourly temporal resolution. We used NO2 column measurements from Tropospheric Emissions: Monitoring of Pollution (TEMPO) with a new fitting function, the rise-decay (RD) model, to derive NOx emissions at 64 power plants in the continental United States. The RD model separately fits the [...]
A Changing North Atlantic Background Amplifies Western European Heatwaves
Published: 2026-09-06
Subjects: Atmospheric Sciences, Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Western European summer heatwaves have increased markedly since the 1990s, culminating in the record warmth of May–July 2026 since 1950. We show that this rise is closely associated with the slowly evolving North Atlantic background. We combine two leading April sea surface temperature modes, representing basin-wide warming and a tripole-like pattern, into an Atlantic Two-Mode Index (ATMI). The [...]
Methodological Bias between Trajectory Geometric Co-location and Air-Parcel Lagrangian Co-location: Evidence from UAV Re-penetration Observations over the Western Sichuan Plateau
Published: 2026-09-05
Subjects: Atmospheric Sciences, Meteorology
Whether "trajectory geometric co-location" is equivalent to "air-parcel Lagrangian co-location" remains a methodological blind spot in evaluating UAV cloud-seeding re-penetration (the UAV performed a repeated cloud penetration—hereafter, re-penetration—to re-sample the same cloud volume). Using silver iodide (AgI) seeding observations from a Wing Loong-2 UAV flight over the Western Sichuan [...]
Automated identification, industrial attribution and conditional emission-rate quantification of recurrent CO enhancement source regions from TROPOMI observations
Published: 2026-09-03
Subjects: Atmospheric Sciences, Remote Sensing
The TROPOspheric Monitoring Instrument (TROPOMI) repeatedly measures global carbon monoxide (CO) total columns, but industrial CO studies generally begin with known cities or facilities; a general method is therefore needed to discover where enhancements recur globally. We developed an automated workflow that searches without facility coordinates. A weakly supervised model screens scenes for [...]
Evaluating forecast baselines and network representativeness for daily PM2.5 in the Kathmandu Valley, Nepal
Published: 2026-09-03
Subjects: Atmospheric Sciences, Climate, Environmental Indicators and Impact Assessment, Environmental Monitoring, Meteorology
An order-fair attribution of daily PM2.5 predictability in the Kathmandu Valley assigns 72% of achievable error reduction to persistence, 19% to meteorology and 9% to day-of-year climatology, with the latter two largely redundant; no fitted model, including random forests and gradient boosting tuned by nested chronological cross-validation, outperforms an unfitted lag-1 forecast (11.22 µg m-3). [...]
Super El Niño Winters and the Arctic Polar Vortex: Response Heterogeneity, QBO Modulation, and a Prospectively Defined Test for Winter 2026/27
Published: 2026-08-30
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Other Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
In the three strongest El Niño winters of the instrumental record (1982/83, 1997/98, 2015/16) the Arctic polar vortex did not collapse in a major midwinter sudden stratospheric warming (SSW). This study starts from the premise that the observation is not a paradox: 58% of El Niño winters contain at least one major SSW, so the chance probability of three consecutive SSW-free winters is 0.42³≈0.07, [...]
Contrasting oil and gas methane emission intensities across Algeria's major production basins derived using MethaneSAT data
Published: 2026-08-28
Subjects: Atmospheric Sciences, Climate, Natural Resources Management and Policy, Oil, Gas, and Energy
Algeria, Africa's largest natural gas producer and a major European Union gas supplier, has limited basin-scale assessment of oil and gas methane emissions. Here, we use MethaneSAT observations from September 2024 to May 2025 to quantify methane emissions across three Algerian production regions representing 73% of national onshore production. Total methane emissions are 18 t h⁻¹ [11–25] in Hassi [...]
Coupling between Walker and Hadley circulations mediated by low cloud feedback
Published: 2026-08-28
Subjects: Atmospheric Sciences, Climate
The tropical Pacific hosts the primary region of deep convection and forms the shared ascending branch of the Walker and Hadley circulations, which regulate the distribution of energy, angular momentum, and moisture across the climate system. Despite their importance and spatial entanglement, the dynamical coupling between these two circulations remains poorly understood. Here we show that the [...]
Biological Dynamics for Sustainable Carbon Sequestration
Published: 2026-08-27
Subjects: Atmospheric Sciences, Biology, Climate, Environmental Microbiology and Microbial Ecology Life Sciences, Forest Management, Planetary Biogeochemistry
Earth’s atmosphere is shaped by the interplay of biological systems operating across interlinked biogeochemical cycles and, more recently, by anthropogenic emissions. Here, we thoroughly examine the potential for engineering biological systems across ecosystems for sustainable carbon storage. This centralization and comparative analysis of the potential of all key global ecosystems aims to [...]
Boxology: the isobar–thickness box count as an exact advection integral, and its rendering
Published: 2026-08-24
Subjects: Atmospheric Sciences, Meteorology, Oceanography and Atmospheric Sciences and Meteorology
"Boxology" is the hand-analysis practice of reading thermal advection from the angle at which mean-sea-level-pressure isobars cross 1000-500 hPa thickness contours: steep crossings cut the chart into small quadrilaterals and imply strong advection, parallel families imply none. This note shows the practice is an identity within geostrophic balance rather than a rule of thumb, and implements it as [...]
Independent lidar observations support declining low cloud cover trends seen in satellite and reanalysis records
Published: 2026-08-21
Subjects: Atmospheric Sciences, Climate
Low clouds strongly influence Earth's radiation budget, yet their response to climate change remains uncertain. Recent satellite and reanalysis studies indicate declining low cloud cover that may have contributed to increasing absorbed solar radiation, but independent ground-based evidence over land is limited. Here we show that ground-based lidar observations support a decrease in low cloud [...]
Large-Scale Modulation of Mesoscale Convective System Propagation and Diurnal Rainfall over the Western Maritime Continent
Published: 2026-08-14
Subjects: Atmospheric Sciences, Climate, Meteorology
The western Maritime Continent exhibits a pronounced regional diurnal cycle of rainfall, to which the propagating Mesoscale Convective Systems (MCSs) make a significant contribution. Using an automated tracking algorithm based on brightness temperature, we quantify the contribution of MCSs to the regional diurnal cycle over Singapore and the South China Sea. MCSs affecting the Singapore sector [...]