Preprints
Filtering by Subject: Atmospheric Sciences
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 whichmean-sea-level-pressure isobars cross 1000–500 hPa thickness contours: steep crossings cut thechart into small quadrilaterals and imply strong advection, while parallel families imply none.This note shows the practice is an identity within geostrophic balance rather than a rule ofthumb, and implements it [...]
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 [...]
Methane emissions intensity mapping from space reveals outsized emissions impact from marginal oil and gas production in the U.S.
Published: 2026-08-09
Subjects: Atmospheric Sciences, Environmental Monitoring, Oil, Gas, and Energy
Methane emissions reduction from the oil/gas sector, the largest industrial methane source, is a widely-recognized effective strategy for slowing the rate of climate warming. There are over 600,000 well-pads in the U.S.; one-fifth produce most of the economic value, while the remainder produce limited oil/gas. We use high-resolution MethaneSAT satellite data covering >80% of US onshore [...]
SCI-VIS: Lightweight Visibility Tagging for Coastal Camera Monitoring
Published: 2026-07-29
Subjects: Atmospheric Sciences, Environmental Monitoring, Oceanography, Remote Sensing
Observations and measurements made from coastal cameras are conditional on the frame being interpretable. Sea fog, glare, rain and condensation on the housing, haze and low light each degrade the imagery, and the shoreline positions, wave measurements and counts derived from a degraded frame are corrupted or spurious. This paper evaluates a per-frame visibility classifier, based on a compact [...]
Cloud-Free Imaging Probability Forecasting for Optical Earth-Observation Tasking over Yerevan, Armenia
Published: 2026-07-17
Subjects: Artificial Intelligence and Robotics, Atmospheric Sciences, Environmental Monitoring, Numerical Analysis and Scientific Computing, Remote Sensing
Optical Earth-observation satellites such as Sentinel-2 cannot see through cloud, so a tasking attempt over a cloudy target wastes a limited imaging window along with onboard power and downlink bandwidth. We study whether next-day cloud conditions over Yerevan, Armenia can be forecast accurately enough to automate the binary Go/No-Go tasking decision. Daily cloud-free fractions are derived from [...]
Historical Pattern Effects and Climate Sensitivity Revisited with Novel Constraints on Past Warming Patterns
Published: 2026-07-17
Subjects: Atmospheric Sciences, Climate, Oceanography and Atmospheric Sciences and Meteorology
The historical record (1850–present) can constrain equilibrium climate sensitivity (ECS) only if we know the patterns of sea-surface temperature (SST) and sea ice concentration (SIC) that shape radiative feedbacks. Feedbacks depend on spatial patterns of SST and SIC (“pattern effects”), yet the impact of historical SST/SIC uncertainty on feedback estimates has not been systematically quantified. [...]