Atlantic overturning inferred from air-sea heat fluxes indicates no decline since the 1960s

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: Jan. 15, 2025

The Atlantic Meridional Overturning Circulation (AMOC) is crucial for global ocean carbon and heat uptake, controls the climate around North Atlantic. Despite its importance, quantifying AMOC's past changes assessing vulnerability to change remains highly uncertain. Understanding AMOC has relied on proxies, most notably sea surface temperature anomalies over subpolar Here, we use 24 Earth System Models from Coupled Model Intercomparison Project Phase 6 (CMIP6) demonstrate that these cannot robustly reconstruct AMOC. Instead, find air-sea flux north of any given latitude in between 26.5°N 50°N are tightly linked anomaly at decadal centennial timescales. On timescales, strongly AMOC-driven northward through conservation energy. annual however, mostly altered by atmospheric variability less anomalies. Based here identified relationship observation-based estimates reanalysis products, averaged not weakened 1963 2017 although substantial exists all latitudes. overturning circulation authors CMIP6 25.6°N this relationship, they 26.5° 2017.

Language: Английский

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Freshwater input from glacier melt outside Greenland alters modeled northern high-latitude ocean circulation

Earth System Dynamics, Journal Year: 2025, Volume and Issue: 16(2), P. 347 - 377

Published: March 4, 2025

Abstract. As anthropogenic climate change depletes Earth's ice reservoirs, large amounts of fresh water are released into the ocean. Since ocean has a major influence on climate, understanding how changes in response to an increased freshwater input is crucial for ongoing shifts system. Moreover, comprehend evolution ice–ocean interactions, it important investigate if and might affect marine-terminating glaciers' stability. Though most attention this context been from Greenland, other Northern Hemisphere glacierized regions losing mass at combined rate roughly half that Greenland should not be neglected. In order get first estimate glacier loss around Arctic affects potential circulation glaciers, we conduct one-way coupled experiments with general model (NEMO-ANHA4) (Open Global Glacier Model; OGGM) years 2010 2019. We find increase heat content Baffin Bay due enhanced gyre leads transport through Davis Strait. also subpolar gyre's structure: density decrease sea surface height eastern part vice versa western part. Additionally, decreased Barents Sea Svalbard Russian Arctic. The rerouting Atlantic Opening Fram Strait Ocean thickness area.

Language: Английский

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Eutrophication Exacerbates Microplastic Bioaccumulation Risks in Coastal Fish

Environmental Science & Technology, Journal Year: 2025, Volume and Issue: unknown

Published: April 22, 2025

Microplastic bioaccumulation (MPB) within marine fish through the food chain has been extensively validated in traditional experimental studies. However, idealized conditions of these studies fail to fully capture complex, nonlinear interactions among microplastics, biota, and environmental factors real-world scenarios, spatiotemporal characteristics risks are lacking studies, hindering accurate assessment control risk. To address above knowledge gaps, we constructed an improved sparrow search algorithm/geographic random forest (ISSA-GRF) conceptual framework analyzed MPB 82 common species from coastal ecosystems. The rate 22 major ecosystems increased by average 3.56% over past decade. Hotspot areas such as Red Sea coast, Gulf Thailand Sulawesi coast were identified; rates 8.00%, 5.68%, 5.34%, respectively. Ocean eutrophication, triggered changes nutrient levels, was revealed main driver via a causal analysis. These findings not only independently validate increasing risk microplastic biological accumulation outside laboratory environment but also highlight importance controlling eutrophication mitigate associated with microplastics.

Language: Английский

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Understanding Possible Physical Mechanisms Associated With Variability of March to May Seasonal Extreme Wettest Days Rainfall in Tanzania

International Journal of Climatology, Journal Year: 2025, Volume and Issue: unknown

Published: April 29, 2025

ABSTRACT Extreme rainfall remains the most impactful natural disaster affecting environment and ecological system in Tanzania. Understanding possible physical mechanisms behind these events is crucial for mitigating associated risks. Therefore, interannual variability of extreme wettest days (EWDs) during March to May from 1981 2020 was examined using daily ground observations gridded data Climate Hazards Group InfraRed Precipitation with Station data. EWDs were determined by 99th percentile‐based method. The assessed empirical orthogonal function (EOF) wavelet methods. To understand their connectivity mechanisms, methods such as regression correlation applied analysis. Results show a significant increase under 95% confidence level, especially recent years, notable peak 2020, explaining 19.3% variance leading EOF1, which positively loaded across EOF1's principal component exhibits predominantly positive values, indicating close relationship between high regions EWDs. Wavelet analysis reveals oscillations at 2 5‐year intervals, linked climate phenomena like Indian Ocean Dipole El Niño‐Southern Oscillation. Climatologically, southwest‐oriented vertical integrated moisture flux (VIMF) vectors are predominant, moving westward over Tanzania due an anticyclonic southwestern Ocean. study concludes that EWD influenced convergence southerly westerly VIMF along Tanzania's coastal zone western Warming sea surface temperature anomalies various oceans (i.e., northwestern Atlantic Ocean, tropical northern Pacific Ocean) correlated These enhance or suppress creating low (upper) level (divergence) winds linking ascending (sinking) limb Walker‐type circulation (Pacific Atlantic)

Language: Английский

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Attributing climate and weather extremes to Northern Hemisphere sea ice and terrestrial snow: progress, challenges and ways forward

npj Climate and Atmospheric Science, Journal Year: 2025, Volume and Issue: 8(1)

Published: May 3, 2025

Abstract Sea ice and snow are crucial components of the cryosphere climate system. Both sea spring in Northern Hemisphere (NH) have been decreasing at an alarming rate a changing climate. Changes NH linked with variety weather extremes including cold spells, heatwaves, droughts wildfires. Understanding these linkages will benefit predictions extremes. However, existing work on this has largely fragmented is subject to large uncertainties physical pathways methodologies. This prevented further substantial progress attributing change, potentially risk loss critical window for effective change mitigation. In review, we synthesize current by evaluating observed linkages, their pathways, suggesting ways forward future research efforts. By adopting same framework both snow, highlight combined influence cryospheric feedback We suggest that from improving observational networks, addressing causality complexity using multiple lines evidence, large-ensemble approaches artificial intelligence, achieving synergy between different methodologies/disciplines, widening context, coordinated international collaboration.

Language: Английский

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