Separation of internal and forced variability of climate using a U-Net DOI Open Access
Constantin Bône, Guillaume Gastineau, Sylvie Thiria

et al.

Authorea (Authorea), Journal Year: 2023, Volume and Issue: unknown

Published: Aug. 22, 2023

The internal variability pertains to fluctuations originating from processes inherent the climate component and their mutual interactions. On other hand, forced delineates influence of external boundary conditions on physical system. A methodology is formulated distinguish between within surface air temperature. noise-to-noise approach employed for training a neural network, drawing an analogy image noise. large dataset compiled using temperature data spanning 1901 2020, obtained ensemble Atmosphere-Ocean General Circulation Model (AOGCM) simulations. network utilized U-Net, widely adopted convolutional primarily designed segmentation. To assess performance, comparisons are made outputs two single-model initial-condition ensembles (SMILEs), mean, U-Net’s predictions. U-Net reduces by factor four, although notable discrepancies observed at regional scale. While demonstrating effective filtering El Niño Southern Oscillation, encounters challenges in areas dominated variability, such as Arctic sea ice retreat region. This holds potential extension variables, facilitating insights into enduring changes triggered forcings over long term.

Language: Английский

Petrogenesis of Mesoproterozoic kimberlites in the Chigicherla region, Eastern Dharwar craton, Southern India: Insights into the origin of small-volume, enriched-mantle derived melts and link to subduction and supercontinent cycle DOI

Hero Kalra,

Ashish Dongre, Fanus Viljoen

et al.

Journal of Asian Earth Sciences, Journal Year: 2025, Volume and Issue: unknown, P. 106508 - 106508

Published: Feb. 1, 2025

Language: Английский

Citations

1
Comparison of UKESM1 and CESM2 simulations using the same multi-target stratospheric aerosol injection strategy DOI Creative Commons

Matthew Henry,

Jim Haywood, Andy Jones

et al.

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(20), P. 13369 - 13385

Published: Oct. 24, 2023

Abstract. Solar climate intervention using stratospheric aerosol injection (SAI) has been proposed as a method which could offset some of the adverse effects global warming. The Assessing Responses and Impacts on Earth system with Stratospheric Aerosol Injection (ARISE-SAI) set simulations is based moderate-greenhouse-gas-emission scenario employs sulfur dioxide at four off-equatorial locations control algorithm maintains global-mean surface temperature 1.5 K above pre-industrial conditions (ARISE-SAI-1.5), well latitudinal gradient inter-hemispheric difference in temperature. This first comparison between two models (CESM2 UKESM1) applying same multi-target SAI strategy. CESM2 successful reaching its targets, but UKESM1 considerable residual Arctic occurs because pattern change determined by both structure forcing (mainly greenhouse gases aerosols) models' feedbacks, latter favour strong amplification warming UKESM1. Therefore, research constraining level future would also inform any hypothetical deployment strategy aims to maintain Equator-to-pole near-surface differences. Furthermore, despite broad agreement precipitation response extratropics, changes over tropical land show important inter-model differences, even under gas only. In general, this ensemble step comparing policy-relevant scenarios will help design an experimental protocol reduces known negative side simple enough encourage more participate.

Language: Английский

Citations

22
Uncertainties in critical slowing down indicators of observation-based fingerprints of the Atlantic Overturning Circulation DOI Creative Commons
Maya Ben‐Yami, Vanessa Skiba, Sebastian Bathiany

et al.

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Dec. 15, 2023

Observations are increasingly used to detect critical slowing down (CSD) measure stability changes in key Earth system components. However, most datasets have non-stationary missing-data distributions, biases and uncertainties. Here we show that, together with the pre-processing steps deal them, these can bias CSD analysis. We present an uncertainty quantification method address such issues. how propagate uncertainties provided analysis develop conservative, surrogate-based significance tests on indicators. apply our three observational sea-surface temperature salinity fingerprints of Atlantic Meridional Overturning Circulation derived from them. find that properties especially specific gap filling procedures some cases indeed cause false indication CSD. indicators North still significant when accounting for dataset coverage.

Language: Английский

Citations

16
Uncertainties too large to predict tipping times of major Earth system components from historical data DOI Creative Commons
Maya Ben‐Yami, Andreas Morr, Sebastian Bathiany

et al.

Science Advances, Journal Year: 2024, Volume and Issue: 10(31)

Published: Aug. 2, 2024

One way to warn of forthcoming critical transitions in Earth system components is using observations detect declining stability. It has also been suggested extrapolate such stability changes into the future and predict tipping times. Here, we argue that involved uncertainties are too high robustly We raise concerns regarding (i) modeling assumptions underlying any extrapolation historical results future, (ii) representativeness individual component time series, (iii) impact preprocessing used observational datasets, with focus on nonstationary coverage gap filling. explore these general specifically for example Atlantic Meridional Overturning Circulation. even under assumption a given an approaching point, large reliably estimate times by extrapolating information.

Language: Английский

Citations

6
Global total precipitable water variations and trends over the period 1958–2021 DOI Creative Commons
Nenghan Wan, Xiaomao Lin,

Roger A. Pielke

et al.

Hydrology and earth system sciences, Journal Year: 2024, Volume and Issue: 28(9), P. 2123 - 2137

Published: May 15, 2024

Abstract. Global responses of the hydrological cycle to climate change have been widely studied, but uncertainties still remain regarding water vapor lower-tropospheric temperature. Here, we investigate trends in global total precipitable (TPW) and surface temperature from 1958 2021 using ERA5 JRA-55 reanalysis datasets. We further validate these radiosonde 1979 2019 Atmospheric Infrared Sounder (AIRS) Special Sensor Microwave Imager/Sounder (SSMIS) observations 2003 2021. Our results indicate a increase ∼ 2 % per decade 1993–2021. These variations TPW reflect interactions warming feedback mechanisms across different spatial scales. also revealed significant near-surface (T2 m) trend 0.15 K decade−1 over period 1958–2021. The consistent at rate 0.21 after 1993 corresponds strong response 9.5 K−1 globally, with land areas approximately twice as fast oceans. relationship between T2 m showed variation around 6 K−1–8 15–55° N latitude band, aligning theoretical estimates Clausius–Clapeyron equation.

Language: Английский

Citations

5
Evidence lacking for a pending collapse of the Atlantic Meridional Overturning Circulation DOI
Xianyao Chen, Ka Kit Tung

Nature Climate Change, Journal Year: 2023, Volume and Issue: 14(1), P. 40 - 42

Published: Nov. 30, 2023

Language: Английский

Citations

13
Comparison of UKESM1 and CESM2 Simulations Using the Same Multi-Target Stratospheric Aerosol Injection Strategy DOI Creative Commons

Matthew Henry,

Jim Haywood, Andy Jones

et al.

Published: June 5, 2023

Abstract. Solar climate intervention using stratospheric aerosol injection (SAI) has been proposed as a method which could offset some of the adverse effects global warming. The Assessing Responses and Impacts on Earth system with Stratospheric Aerosol Injection (ARISE-SAI) set simulations is based moderate greenhouse gas emission scenario employs sulphur dioxide at four off-equatorial locations control algorithm maintains global-mean surface temperature 1.5 K above preindustrial conditions (ARISE-SAI-1.5), well latitudinal gradient inter-hemispheric difference in temperature. This first comparison between two models (CESM2 UKESM1) applying same multi-target SAI strategy. CESM2 successful reaching its targets, but UKESM1 considerable residual Arctic occurs because pattern change geoengineered determined both by structure forcing (mainly gases aerosols) models’ feedbacks, latter favour strong amplification warming UKESM1. Therefore, research constraining level future would also inform any hypothetical deployment strategy aims to maintain interhemispheric equator-to-pole near-surface differences. Furthermore, despite broad agreement precipitation response extratropics, changes over tropical land show important inter-model differences, even under only. In general, this ensemble step comparing policy-relevant scenarios SAI, will help design an experimental protocol reduces known negative side simple enough encourage more participate.

Language: Английский

Citations

11
Projections of the North Atlantic warming hole can be constrained using ocean surface density as an emergent constraint DOI Creative Commons
In‐Hong Park, Sang‐Wook Yeh

Communications Earth & Environment, Journal Year: 2024, Volume and Issue: 5(1)

Published: Feb. 23, 2024

Abstract There are large uncertainties in the projections of future warming hole, which is defined as cooling trend subpolar North Atlantic Ocean despite global warming. Here, we found that uncertainty changes hole mainly due to model bias rather than either natural variability or climate change scenario. Observations and results constrain intensity terms its relationship with present-day surface density Atlantic. Models a low tend project weaker (i.e., stronger temperature increase) suppressed oceanic deep convection models high density. This was robust across all scenarios used reduce by 39% emissions

Language: Английский

Citations

4
Structural stability changes of the Atlantic Meridional Overturning Circulation DOI Creative Commons
Mihai Dima, Gerrit Lohmann,

Denis‐Răducu Nichita

et al.

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

Published: Feb. 25, 2025

Language: Английский

Citations

0
Analyzing climate scenarios using dynamic mode decomposition with control DOI Creative Commons
Nathan Mankovich, Shahine Bouabid, Peer Nowack

et al.

Environmental Data Science, Journal Year: 2025, Volume and Issue: 4

Published: Jan. 1, 2025

Abstract Understanding the complex dynamics of climate patterns under different anthropogenic emissions scenarios is crucial for predicting future environmental conditions and formulating sustainable policies. Using Dynamic Mode Decomposition with control (DMDc), we analyze surface air temperature from simulations to elucidate effects various climate-forcing agents. This improves upon previous DMD-based methods by including forcing information as a variable. Our study identifies both common patterns, like North Atlantic Oscillation El Niño Southern Oscillation, distinct impacts aerosol carbon emissions. We show that these emissions’ vary scenarios, particularly higher radiative forcing. findings confirm DMDc’s utility in analysis, highlighting its role extracting modes variability while controlling contributions exposing trends spatial change.

Language: Английский

Citations

0