Preprints
Filtering by Subject: Atmospheric Sciences
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 [...]
Remote sensing of ammonia point sources at high spatial resolution with satellite-based imaging spectrometers
Published: 2026-06-24
Subjects: Atmospheric Sciences, Environmental Monitoring
Ammonia (NH3) emissions play a key role in air pollution and the disruption of the nitrogen cycle. Global emissions of ammonia are expected to increase in the future, making their monitoring essential to better understand their impacts and to support effective environmental policies. Recent studies have demonstrated the potential of satellite imaging spectrometers operating in the shortwave [...]
Performance validation of the GHGSat Methane Constellation via controlled releases
Published: 2026-06-20
Subjects: Atmospheric Sciences, Environmental Monitoring
Satellite remote sensing has become an important tool for detecting, quantifying, and attributing methane emissions, yet a rigorous, condition-dependent characterization of point-source imager performance has not previously been established, despite being essential to support its use in regulatory and voluntary reporting frameworks. We present a comprehensive performance assessment of the GHGSat [...]
Toward Fit-for-Purpose Evapotranspiration Observations
Published: 2026-06-20
Subjects: Atmospheric Sciences, Earth Sciences, Hydrology, Oceanography and Atmospheric Sciences and Meteorology
Evapotranspiration (ET) underpins water, energy, and carbon cycling, yet remains among the least observed hydrologic fluxes, creating a persistent paradox: hydrology is advancing rapidly through artificial intelligence and data-driven methods while its observational foundation remains sparse and fragmented. Eddy covariance provides robust ET measurements, but high cost and operational demands [...]
Why the Earth Exhibits Interhemispheric Albedo Symmetry: Erosion–formation asymmetry of low-cloud responses to circulation reorganization.
Published: 2026-06-16
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Earth exhibits a striking near symmetry in interhemispheric mean albedo despite substantial asymmetries in surface properties, aerosols, and geography. Whether this symmetry is coincidental or dynamically constrained remains unresolved. Here we present a minimal theoretical framework showing that a moist atmosphere provides a physically constrained, but bounded, tendency to oppose [...]
Implicit-tuning signal quantified through a tri-experiment design in a legacy spectral GCM
Published: 2026-06-15
Subjects: Atmospheric Sciences, Climate, Numerical Analysis and Scientific Computing
We quantify the climate response of the MGO atmospheric general circulation model (MGO-03 T42L25) to two alternative implementations of a structural fix in the vertical-exchange parameterization. A companion parallelization study (under review) identifies an unintended inter-latitude state leakage through SAVE-persistent working arrays in the boundary-layer scheme. Here we contrast the legacy [...]
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 [...]
Two decades of kilometer-scale daily PM2.5 from satellite observations and machine learning reveal geographically diverging exposure in Ghana
Published: 2026-06-06
Subjects: Artificial Intelligence and Robotics, Atmospheric Sciences, Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Environmental Monitoring, Environmental Public Health, Environmental Sciences, Geographic Information Sciences, Geography, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Remote Sensing, Spatial Science
Exposure to fine particulate matter (PM2.5) is a major contributor to global burden of disease, yet air quality data remain sparse in many low- and middle-income countries, limiting nationwide monitoring and effective policy development. We address this gap by developing a high-resolution gridded (1 km × 1 km) dataset for daily surface PM2.5 concentrations in Ghana from 2005 to 2025 by training [...]
Empirical constraints on the fraction of surface latent heat flux reaching the top of atmosphere as net radiative cooling
Published: 2026-06-04
Subjects: Atmospheric Sciences, Climate, Hydrology
The transfer fraction η, defined as the ratio of net cloud radiative effect at the top of atmosphere to surface latent heat flux (η = |CRE_net| / LE), is a fundamental coupling parameter linking surface hydrology to TOA radiation. Despite its relevance to cloud feedback and biophysical forcing, η has not been directly constrained by co-located observations at the spatial scales relevant to [...]
The three causal pathways of ENSO teleconnections to High Mountain Asia winter precipitation
Published: 2026-06-04
Subjects: Atmospheric Sciences, Climate
High Mountain Asia (HMA), spanning from the Hindu Kush to the Tibetan Plateau, encompasses tropical and subtropical regions highly susceptible to extreme precipitation events and associated hazards. El Niño–Southern Oscillation (ENSO) is one of the dominant external climate modes that influence subseasonal to seasonal precipitation over HMA through various dynamical pathways. We hypothesize three [...]
Spatially and temporally dense measurements reveal meteorological driver of atmospheric mercury variability
Published: 2026-06-02
Subjects: Atmospheric Sciences
The environmental fate of mercury (Hg) is determined by its atmospheric processing, yet the relative role of surface fluxes, chemistry, and transport on atmospheric loadings remains poorly understood. We use multiyear gaseous elemental Hg (Hg0) concentration measurements at two rural sites and two urban sites in the northeastern US coordinated by the National Atmospheric Deposition Program (NADP) [...]
Development and Evaluation of the High-Resolution MUSICA UK Domain: A Case Study of Global and Regional Biomass Burning Impacts
Published: 2026-05-29
Subjects: Atmospheric Sciences, Civil and Environmental Engineering, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Regional air quality models provide insights into local pollution and exposure, but limitations in representing large-scale atmospheric processes and long-range transport can introduce inconsistencies across spatial scales, which can be addressed using multi-scale chemical transport models. We develop the first UK-specific regionally refined grid (UKne30×16; ∼7 km), alongside a global uniform [...]
Public Understanding of the Atmospheric River Scale
Published: 2026-05-27
Subjects: Atmospheric Sciences, Social and Behavioral Sciences
Atmospheric rivers (ARs) are long, narrow bands of moisture in the atmosphere that transport large amounts of water vapor, producing hazards ranging from heavy rain to high winds once they reach land. In 2019, researchers at the Center for Western Weather and Water Extremes, with partners including the National Weather Service and the California Department of Water Resources, developed the AR [...]
Wildfire smoke offsets decades of progress in reducing ozone exposure across the United States
Published: 2026-05-23
Subjects: Atmospheric Sciences, Climate, Environmental Sciences
Ground-level ozone (O3) pollution has declined in the U.S., yet the progress has stalled in recent years, coinciding with increasing wildfire smoke. Using ensemble machine learning models trained on surface observations, we develop a gridded daily smoke O3 dataset across the contiguous U.S. from 2006-2023. We estimate that wildfire smoke placed an additional 29 million people each year in areas [...]
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 [...]