Browse
Submit Data
Databases
API
Help

Dataset Information

28 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Assessing the impact of suppressing Southern Ocean SST variability in a coupled climate model.

ABSTRACT: The Southern Ocean exerts a strong influence on global climate, regulating the storage and transport of heat, freshwater and carbon throughout the world's oceans. While the majority of previous studies focus on how wind changes influence Southern Ocean circulation patterns, here we set out to explore potential feedbacks from the ocean to the atmosphere. To isolate the role of oceanic variability on Southern Hemisphere climate, we perform coupled climate model experiments in which Southern Ocean variability is suppressed by restoring sea surface temperatures (SST) over 40°-65°S to the model's monthly mean climatology. We find that suppressing Southern Ocean SST variability does not impact the Southern Annular Mode, suggesting air-sea feedbacks do not play an important role in the persistence of the Southern Annular Mode in our model. Suppressing Southern Ocean SST variability does lead to robust mean-state changes in SST and sea ice. Changes in mixed layer processes and convection associated with the SST restoring lead to SST warming and a sea ice decline in southern high latitudes, and SST cooling in midlatitudes. These results highlight the impact non-linear processes can have on a model's mean state, and the need to consider these when performing simulations of the Southern Ocean.

SUBMITTER: Purich A

PROVIDER: S-EPMC8585967 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Decadal climate predictability in the southern Indian Ocean captured by SINTEX-F using a simple SST-nudging scheme.

Project description:Decadal climate variability in the southern Indian Ocean has great influences on southern African climate through modulation of atmospheric circulation. Although many efforts have been made to understanding physical mechanisms, predictability of the decadal climate variability, in particular, the internally generated variability independent from external atmospheric forcing, remains poorly understood. This study investigates predictability of the decadal climate variability in the southern Indian Ocean using a coupled general circulation model, called SINTEX-F. The ensemble members of the decadal reforecast experiments were initialized with a simple sea surface temperature (SST) nudging scheme. The observed positive and negative peaks during late 1990s and late 2000s are well reproduced in the reforecast experiments initiated from 1994 and 1999, respectively. The experiments initiated from 1994 successfully capture warm SST and high sea level pressure anomalies propagating from the South Atlantic to the southern Indian Ocean. Also, the other experiments initiated from 1999 skillfully predict phase change from a positive to negative peak. These results suggest that the SST-nudging initialization has the essence to capture the predictability of the internally generated decadal climate variability in the southern Indian Ocean.

| S-EPMC5786087 | biostudies-other

Critical Southern Ocean climate model biases traced to atmospheric model cloud errors.

Project description:The Southern Ocean is a pivotal component of the global climate system yet it is poorly represented in climate models, with significant biases in upper-ocean temperatures, clouds and winds. Combining Atmospheric and Coupled Model Inter-comparison Project (AMIP5/CMIP5) simulations, with observations and equilibrium heat budget theory, we show that across the CMIP5 ensemble variations in sea surface temperature biases in the 40-60°S Southern Ocean are primarily caused by AMIP5 atmospheric model net surface flux bias variations, linked to cloud-related short-wave errors. Equilibration of the biases involves local coupled sea surface temperature bias feedbacks onto the surface heat flux components. In combination with wind feedbacks, these biases adversely modify upper-ocean thermal structure. Most AMIP5 atmospheric models that exhibit small net heat flux biases appear to achieve this through compensating errors. We demonstrate that targeted developments to cloud-related parameterisations provide a route to better represent the Southern Ocean in climate models and projections.

| S-EPMC6134029 | biostudies-literature

Ocean mesoscale mixing linked to climate variability.

Project description:Mesoscale turbulence in the ocean strongly affects the circulation, water mass formation, and transport of tracers. Little is known, however, about how mixing varies on climate timescales. We present the first time-resolved global dataset of lateral mesoscale eddy diffusivities at the ocean surface, obtained by applying the suppressed mixing length theory to satellite-observed velocities. We find interannual variability throughout the global ocean, regionally correlated with climate indices such as ENSO, NAO, DMI, and PDO. Changes in mixing length, driven by variations in the large-scale flow, often exceed the effect of variations in local eddy kinetic energy, previously thought of as the primary driver of variability in eddy mixing. This mechanism, not currently represented in global climate models, could have far-reaching consequences for the distribution of heat, salt, and carbon in the global ocean, as well as ecosystem dynamics and regional dynamics such as ENSO variance.

| S-EPMC6357734 | biostudies-literature

Upper Ocean Cooling in a Coupled Climate Model Due to Light Attenuation by Yellowing Materials.

Project description:Colored detrital matter consists of dissolved organic molecules and detrital materials that impart a yellow shift to the ocean's color. These materials reduce light penetration, concentrating heating by sunlight closer to the surface. We ran two climate model simulations: one of an ocean including colored detrital matter (Yellow Ocean) and one without (Green Ocean). Due to the decreased water clarity in the Yellow Ocean, upper ocean heat content was lower and temperatures were colder compared to the Green Ocean. The difference between these simulations is opposite to the ocean warming that has been observed in recent decades. Increasing precipitation in high-latitude regions has also been observed, with greater inputs of terrestrial organic materials to the ocean. We suggest that an increase in these yellowing materials behaves as a buffer that mitigates some effects of a warming climate. Future studies should investigate this link between the atmosphere, land, and ocean systems.

| S-EPMC7440400 | biostudies-literature

Influence of internal climate variability on Indian Ocean Dipole properties.

Project description:The Indian Ocean Dipole (IOD) is the dominant mode of interannual variability over the tropical Indian Ocean (IO) and its future changes are projected to impact the climate and weather of Australia, East Africa, and Indonesia. Understanding the response of the IOD to a warmer climate has been largely limited to studies of individual coupled general circulation models or multi-model ensembles. This has provided valuable insight into the IOD's projected response to increasing greenhouse gases but has limitations in accounting for the role of internal climate variability. Using the Community Earth System Model Large Ensemble (CESM-LE), the IOD is examined in thirty-five present-day and future simulations to determine how internal variability influences properties of the IOD and their response to a warmer climate. Despite small perturbations in the initial conditions as the only difference between ensemble members, significant relationships between the mean state of the IO and the IOD arise, leading to a spread in the projected IOD responses to increasing greenhouse gases. This is driven by the positive Bjerknes feedback, where small differences in mean thermocline depth, which are caused by internal climate variability, generate significant variations in IOD amplitude, skewness, and the climatological zonal sea surface temperature gradient.

| S-EPMC6131175 | biostudies-other

Regional Wind Variability Modulates the Southern Ocean Carbon Sink.

Project description:The Southern Ocean south of 35°S accounts for approximately half of the annual oceanic carbon uptake, thereby substantially mitigating the effects of anthropogenic carbon dioxide (CO2) emissions. The intensity of this important carbon sink varies considerably on inter-annual to decadal timescales. However, the drivers of this variability are still debated, challenging our ability to accurately predict the future role of the Southern Ocean in absorbing atmospheric carbon. Analysing mapped sea-air CO2 fluxes, estimated from upscaled surface ocean CO2 measurements, we find that the overall Southern Ocean carbon sink has weakened since ~2011, reversing the trend of the reinvigoration period of the 2000s. Although we find significant regional positive and negative responses of the Southern Ocean carbon uptake to changes in the Southern Annular Mode (SAM) over the past 35 years, the net effect of the SAM on the Southern Ocean carbon sink variability is approximately zero, due to the opposing effects of enhanced outgassing in upwelling regions and enhanced carbon uptake elsewhere. Instead, regional shifts in sea level pressure, linked to zonal wavenumber 3 (ZW3) and related changes in surface winds substantially contribute to the inter-annual to decadal variability of the Southern Ocean carbon sink.

| S-EPMC6517586 | biostudies-literature

Arctic-Eurasian climate linkage induced by tropical ocean variability.

Project description:Eurasian continent has experienced cold winters over the past two decades in contrast with Arctic warming. Previous studies have suggested that the cold Eurasian winters are associated with Arctic sea-ice loss, while others attributed them to atmospheric internal variability. However, here we show that the Arctic and Eurasian climate linkage is driven by the combination between atmospheric teleconnection originating in the tropical oceans and Arctic sea ice. Like a battery charges a capacitor, El Niño heats the tropical Atlantic, and the warmer Atlantic condition persists until early winter of El Niño-decay year. We find that the persisting tropical Atlantic warming induces anomalous Rossby wave train arching to Eurasia, leading to Arctic sea-ice increase and Eurasian warming. In La Niña phase these changes are reversed. Our results therefore suggest that the combination of recent tropical Pacific cooling and Arctic sea-ice loss have contributed to the frequent Eurasian cold winters.

| S-EPMC6672006 | biostudies-literature

Southern Ocean Metagenomes

Project description:SO-METAG

| PRJEB37465 | ENA

Southern Ocean Metatrascnriptomes

Project description:SO-METAT

| PRJEB37466 | ENA

The importance of internal climate variability in climate impact projections.

Project description:Uncertainty in climate projections is driven by three components: scenario uncertainty, intermodel uncertainty, and internal variability. Although socioeconomic climate impact studies increasingly take into account the first two components, little attention has been paid to the role of internal variability, although underestimating this uncertainty may lead to underestimating the socioeconomic costs of climate change. Using large ensembles from seven coupled general circulation models with a total of 414 model runs, we partition the climate uncertainty in classic dose-response models relating county-level corn yield, mortality, and per-capita gross domestic product to temperature in the continental United States. The partitioning of uncertainty depends on the time frame of projection, the impact model, and the geographic region. Internal variability represents more than 50% of the total climate uncertainty in certain projections, including mortality projections for the early 21st century, although its relative influence decreases over time. We recommend including uncertainty due to internal variability for many projections of temperature-driven impacts, including early-century and midcentury projections, projections in regions with high internal variability such as the Upper Midwest United States, and impacts driven by nonlinear relationships.

| S-EPMC9586330 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data