Preprints
Filtering by Subject: Climate
Stable estimates of when global temperature thresholds will be crossed: least-squares fits as the end date of the fitted span is reduced
Published: 2026-07-07
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Reliable estimates of when global mean temperature will exceed the Paris Agreement's 2°C threshold1 are generally derived from emissions scenarios and climate models rather than from the observed temperature record itself. This study investigates whether the observed warming trajectory alone can provide a stable empirical estimate of the crossing date. Least-squares exponential, quadratic and [...]
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 [...]
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 [...]
A Phanerozoic Atlas of Earth’s Atmosphere, Surface, and Interior Derived from the PANALESIS Plate Tectonic Model
Published: 2026-06-22
Subjects: Climate, Earth Sciences, Environmental Sciences, Geology, Other Environmental Sciences, Tectonics and Structure
Reconstructing the Earth system evolution through deep time requires spatially consistent, multi‑layer datasets that integrate geological, geophysical, and climatic information. Here we present a unified, high‑resolution (10×10km) global dataset describing the Earth’s evolution over the past 545 million years. This atlas provides 45 time slices spanning the Phanerozoic, each including quantified [...]
ENSO-Driven Modulation of the Caribbean Subsurface Salinity Maximum
Published: 2026-06-16
Subjects: Climate, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
This study identifies El Niño–Southern Oscillation (ENSO) as the primary driver of interannual subsurface salinity variability in the Caribbean Sea. Using 30 years of high-resolution, data-assimilative ocean reanalysis (1993–2022), we show that the Subsurface Salinity Maximum (SSM) closely tracks ENSO cycles: El Niño events correspond to a saltier and deeper SSM, while La Niña drives a fresher [...]
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: 2026-06-14
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 [...]
Deglacial reconstruction of the spatial extent and intensity of the North Atlantic Subtropical High
Published: 2026-06-13
Subjects: Climate, Physical Sciences and Mathematics
Rainfall-related hazards are growing in southeastern North America (SENA) but well-documented climate-model biases cast doubt on projected rainfall changes. The North Atlantic Subtropical High (NASH) supplies the moisture that drives extreme rainfall in SENA, so reconstructing its past behavior offers a test of model fidelity. Using the hydrogen-isotope composition of leaf-wax biomarkers (δDwax) [...]
A scoping review to map research gaps and opportunities relating to heat-related health hazards in countries surrounding Lake Victoria, Africa.
Published: 2026-06-11
Subjects: Climate, Environmental Public Health, Physical and Environmental Geography, Sustainability
Urban populations in sub-Saharan Africa are at rising risks of climate-related health hazards due to global climate change and uncontrolled rapid urbanization. Despite the increasing recognition of these challenges, the extent to which urban climates impact health outcomes in Africa remains poorly understood. East African countries surrounding the Lake Victoria Basin (Kenya, Uganda, Rwanda, [...]
Novel Data-driven High-Frequency Mass Change Models from GRACE orbit residuals
Published: 2026-06-11
Subjects: Climate, Earth Sciences, Fresh Water Studies, Glaciology, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Other Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
We present a fully data-driven framework for transforming residual K-band range-rate (KBRR) data from GRACE into 5-day mass change models expressed in Equivalent Water Height (EWH). The approach first derives residual range and Line-of-Sight Gravity Differences (LGDs) from monthly post-fit residual range-rates and combines them with 5-day post-fit residuals. A hybrid formulation, merging LGD- and [...]
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 [...]
Simulations of Minnesota water budget components using the Soil-Water-Balance model, past (1981–2022) and future (2040–59 and 2080–99)
Published: 2026-06-08
Subjects: Climate, Hydrology, Water Resource Management
This study presents historical estimates and future projections of net infiltration (potential recharge), actual evapotranspiration (ET), surface runoff, and related water budget components across Minnesota using the USGS Soil Water Balance model, version 2 (SWB). The model was calibrated to streamflow and actual ET observations from 2000–2022, achieving an overall r² of 0.973 with a standard [...]
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: 2026-06-03
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 [...]
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 [...]