Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 1807.05676

On the Warming of the Southern Hemisphere since 1955 and Recent Slowing-Down: Role of Sea Ice, Sun Spot and El Nino Variability

Alfred Laubereau·Hristo Iglev
View original source ↗Read source document ↗Export metadata ↓

Abstract

The importance of the sea ice retreat in the polar regions for the global warming and the role of ice-albedo feedback was recognized by various authors [1,2]. Similar to a recent study of the phenomenon in the Arctic [3] we present a semi-quantitative estimate of the mechanism for the Southern Hemisphere (SH). Using a simple model, we estimate the contribution of ice-albedo feedback to the mean temperature increase in the SH to be 0.5 +/- 0.1 K in the years 1955 to 2015, while from the simultaneous growth of the greenhouse gases (GHG) we derive a direct warming of only 0.2 +/- 0.05 K in the same period. These numbers are in nice accordance with the reported mean temperature rise of 0.75 +/- 0.1 K of the SH in 2015 since 1955 (and relative to 1880). Our data also confirm previously noticed correlations between the annual fluctuations of solar intensity and El Nino observations on the one hand and the annual variability of the SH surface temperature on the other hand. Our calculations indicate a slowing down of the temperature increase during the past few years that is likely to persist. Assuming a continuation of the present trends for the southern sea ice and GHG concentration we predict the further temperature rise to decrease by 33 % in 2015 to 2025 as compared to the previous decade.

Explore related subjects

physics.geo-phphysics.ao-ph

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Alfred Laubereau, Hristo Iglev. 2018-07-16. On the Warming of the Southern Hemisphere since 1955 and Recent Slowing-Down: Role of Sea Ice, Sun Spot and El Nino Variability. https://arxiv.org/abs/1807.05676

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

SPBench: A Multi-Task Evaluation Benchmark for Exploration Seismic Processing

Exploration seismic processing underpins subsurface imaging and resource exploration, but learning-based methods remain difficult to compare across studies. Our survey of 368 papers finds widespread reliance on private or difficult-to-reproduce datasets, with only 25 providing public code. This obscures whether reported gains arise from model design or experimental settings. We introduce the Seismic Processing Benchmark (SPBench), covering six tasks: random noise attenuation, trace interpolation, ground-roll suppression, multiple suppression, deblending, and first-arrival picking. We reproduce 24 supervised methods on 10 datasets under 43 standardized settings and release datasets, implementations, configurations, evaluation scripts, and results. To complement global scores and per-trace pick errors, we introduce signal-component-resolved evaluation (SCoRE) for reconstruction and a reference-free ridge-curvature score (RC_norm) for first-arrival picking. Our analyses show that synthetic rankings do not reliably predict field rankings, with task-dependent agreement when models train within each setting. As degradation strengthens, rankings reorder more under coherent ground roll than under random-like interference. The ridge score agrees with MAE-based model rankings in the evaluated settings, with a mean Kendall correlation of 0.881 across three field surveys, while SCoRE reveals frequency- and energy-dependent differences hidden by global scores. SPBench provides a reproducible basis for comparing learning-based seismic processing methods and characterizes how their relative advantages vary across data settings, degradation strengths, and evaluation criteria.

physics.geo-ph↗
arXiv2026

Assessing foundational atomistic models for iron alloys under Earth's core conditions

We assess the capability of recently developed foundational atomistic models (FAMs) to simulate iron alloys under the extreme pressures and temperatures of Earth's core. Static equations of state for hexagonal close-packed (hcp) and body-centered cubic (bcc) iron, computed using 17 FAMs, are benchmarked against ab initio calculations. Two representative models, MatterSim and MACE, are further evaluated for their ability to reproduce phonon spectra, liquid structure, and melting relations of iron at core conditions. While both models capture several key properties, MACE substantially overestimates the stability of bcc iron and fails to correctly describe the stability of hcp iron. Their performance is also examined for binary liquids, superionic phases, and a seven-component Fe-Ni-Si-S-O-H-C liquid. Although these FAMs were not explicitly trained on data from core conditions, they can reproduce several structural and dynamical properties across a wide range of compositions. However, none of the tested models consistently reproduces all first-principles benchmarks. By analyzing the origins of these discrepancies, we identify several limitations of current FAMs, particularly the lack of an explicit treatment of thermal electronic excitations, which significantly affect phase stability and thermodynamic properties under core conditions. We further discuss directions for improving FAMs to enable predictive simulations of core-forming materials under extreme conditions.

physics.geo-ph↗
arXiv2026

Time-Resolved Surface-Fault Displacement During the 2026 Kumamoto Earthquake From Near-Fault Video

Video recordings can reveal how rapidly fault displacement develops at the Earth's surface, but camera motion and recording artifacts can obscure the ground signal. We analyze a secondary copy of security-camera footage that captured surface displacement during the 28 July 2026 Kumamoto earthquake; the native recording was unavailable and could not be recovered. Two independent image-tracking methods were used. Optical flow follows identifiable image features, whereas normalized cross-correlation (NCC) template matching follows fixed image patches by their similarity. Both measured target-region motion relative to spatially separated reference regions while correcting motion shared by the recording. Image displacement was calibrated to the magnitude of the field-measured offset vector: 1.05 m right-lateral and 0.90 m east-side-up, or 1.383 m in total. We characterize the principal rise by the time required for displacement to progress from 20% to 80% of the selected final level. Across prespecified endpoint choices, optical flow gives 0.866-0.901 s and NCC gives 0.910-0.928 s. These durations correspond to average rates of 0.920-0.958 and 0.895-0.912 m/s, respectively. Checks using independently published tracking windows reproduce the displacement scale, although exact timing is more sensitive in spatially restricted tests. The record also shows an early apparent peak and decline followed by renewed apparent horizontal displacement. Because that later motion may represent either continued ground displacement or the geometry of the secondary recording, neither the permanent endpoint nor physical overshoot can be determined. The most robust conclusion is that the central part of the surface displacement developed in approximately 0.9 s at an average rate near 0.9 m/s.

physics.geo-ph↗