Long-term evolution of ocean eddy activity in a warming world

Beech, Nathan; Rackow, Thomas; Semmler, Tido; Danilov, Sergey; Wang, Qiang; Jung, Thomas

doi:10.1038/s41558-022-01478-3

Cited by 43 publications

(21 citation statements)

References 87 publications

(136 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A vast effort is currently underway to increase the spatial resolution of ocean climate models, in order to resolve mesoscale fronts and eddies, notably in the context of HighResMIP (Haarsma et al, 2016). Positive impacts of resolving ocean eddies on the dynamics of western boundary currents, equatorial currents, and the Antarctic Circumpolar Current have been demonstrated in forced ocean models (Chassignet et al, 2020;Hecht and Hasumi, 2008) as well as in the recent HighResMIP coupled models (Beech et al, 2022;Grist et al, 2018;Roberts et al, 2018Roberts et al, , 2020 for the representation of these currents and heat transports. However, Chassignet et al (2020) did not find systematic improvements in salinity and temperature metrics with resolution.…”

Section: Introductionmentioning

confidence: 99%

The Mixed Layer Depth in the Ocean Model Intercomparison Project (OMIP): Impact of Resolving Mesoscale Eddies

Tréguier

Montégut

Bozec

et al. 2023

Preprint

View full text Add to dashboard Cite

Abstract. The ocean mixed layer is the interface between the ocean interior and the atmosphere or sea ice, and plays a key role in climate variability. It is thus critical that numerical models used in climate studies are capable of a good representation of the mixed layer, especially its depth. Here we evaluate the mixed layer depth (MLD) in six pairs of non-eddying (1° resolution) and eddy-rich (up to 1/16°) models from the Ocean Model Intercomparison Project (OMIP), forced by a common atmospheric state. For model validation, we use an updated MLD dataset computed from observations using the OMIP protocol (a constant density threshold). In winter, low resolution models exhibit large biases in the deep water formation regions. These biases are reduced in eddy-rich models but not uniformly across models and regions. The improvement is most noticeable in the mode water formation regions of the northern hemisphere. Results in the Southern Ocean are more contrasted, with biases of either sign remaining at high resolution. In eddy-rich models, mesoscale eddies control the spatial variability of MLD in winter. Contrary to a hypothesis that the deepening of the mixed layer in anticyclones would make the MLD larger globally, eddy-rich models tend to have a shallower mixed layer at most latitudes than coarser models do. In addition, our study highlights the sensitivity of the MLD computation to the choice of a reference level and the spatio-temporal sampling, which motivates new recommendations for MLD computation in future model intercomparison projects.

show abstract

Section: Introductionmentioning

confidence: 99%

The Mixed Layer Depth in the Ocean Model Intercomparison Project (OMIP): Impact of Resolving Mesoscale Eddies

Tréguier

Montégut

Bozec

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…This is supported by modern observations that the strength of the EAC extension and TF shows an anticorrelation on decadal time scales (Hill et al., 2011). In addition, model simulations reveal an increase of EKE in the EAC extension region and a decrease in the TF when compared to EKE changes between historical timescales (1860–1949) and projections (2061–2090), implying that the long‐term trend in eddy activity may also show an anticorrelation between TF and EAC extension (Beech et al., 2022).…”

Section: Resultsmentioning

confidence: 99%

Intensification of the East Australian Current After ∼1400 CE

Zhai

Mohtadi

Dolman

et al. 2022

Geophysical Research Letters

View full text Add to dashboard Cite

The South Pacific poleward-flowing western boundary current (WBC)-the East Australian Current (EAC)flows along the east coast of Australia and redistributes heat and moisture between the tropics and the mid-latitudes, and thus plays an important role in climate changes in the southwest Pacific. For example, the timing and intensity of EAC changes have been shown to influence both regional climates (e.g., Sprintall et al., 1995) and East Coast lows (severe weather events) along the east Australian coast (Hopkins & Holland, 1997). Specifically, a weaker EAC transport is linked to anomalous cool conditions in New Zealand (Sprintall et al., 1995), whereas a stronger EAC is shown to increase rainfall along the eastern Australian coast (Shi et al., 2008). Furthermore, the EAC also exerts a strong influence on the marine productivity offshore eastern Australia through formation of eddies and coastal upwelling (Roughan & Middleton, 2004;Schaeffer et al., 2014;Suthers et al., 2011). The EAC is the result of the bifurcation of the South Equatorial Current (SEC) between 13° and 25°S (Hu et al., 2015), when it collides with the Queensland Plateau (Ridgway & Dunn, 2003) (Figure S1 in Supporting Information S1). After its formation, the EAC follows the coastline until ∼30°S, where the outflow of the EAC current separates and flows east across the Tasman Sea forming the Tasman Front (TF) (Andrews et al., 1980). A minor portion of the EAC continue to flow south along the Australian coast as EAC extension (Ridgway & Godfrey, 1994;Wyrtki, 1962). The EAC is strongest during austral summer and weakens during the austral winter (Godfrey

show abstract

“…This is because the magnitude of the seasonally integrated bloom is dictated by the sum of intermittent pulses occurring at approximately weekly timescales (as hypothesized for the light green regions in figure 1c [29]). The impact of this understanding is that changes in annual mean chlorophyll-a (and by association the BCP) are tied to forcings that drive sub-seasonal fluctuations [74], such that the impact of climate variability will likely be reflected in localized responses to adjustments in wind [124][125][126] and/or eddy activity [127,128]. That said, although the degree to which largescale atmospheric variability drives intense short-term wind events remains unclear [129,130], a study by Hell et al [131] statistically explored variability in the SAM (i.e.…”

Section: Closing the Gap Between Fine-scales And Long-term Trends: Fu...mentioning

confidence: 99%

Southern Ocean phytoplankton dynamics and carbon export: insights from a seasonal cycle approach

Thomalla

Plessis

Fauchereau

et al. 2023

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

Quantifying the strength and efficiency of the Southern Ocean biological carbon pump (BCP) and its response to predicted changes in the Earth's climate is fundamental to our ability to predict long-term changes in the global carbon cycle and, by extension, the impact of continued anthropogenic perturbation of atmospheric CO 2 . There is little agreement, however, in climate model projections of the sensitivity of the Southern Ocean BCP to climate change, with a lack of consensus in even the direction of predicted change, highlighting a gap in our understanding of a major planetary carbon flux. In this review, we summarize relevant research that highlights the important role of fine-scale dynamics (both temporal and spatial) that link physical forcing mechanisms to biogeochemical responses that impact the characteristics of the seasonal cycle of phytoplankton and by extension the BCP. This approach highlights the potential for integrating autonomous and remote sensing observations of fine scale dynamics to derive regionally optimized biogeochemical parameterizations for Southern Ocean models. Ongoing development in both the observational and modelling fields will generate new insights into Southern Ocean ecosystem function for improved predictions of the sensitivity of the Southern Ocean BCP to climate change. This article is part of a discussion meeting issue 'Heat and carbon uptake in the Southern Ocean: the state of the art and future priorities'.

show abstract

Long-term evolution of ocean eddy activity in a warming world

Cited by 43 publications

References 87 publications

The Mixed Layer Depth in the Ocean Model Intercomparison Project (OMIP): Impact of Resolving Mesoscale Eddies

The Mixed Layer Depth in the Ocean Model Intercomparison Project (OMIP): Impact of Resolving Mesoscale Eddies

Intensification of the East Australian Current After ∼1400 CE

Southern Ocean phytoplankton dynamics and carbon export: insights from a seasonal cycle approach

Contact Info

Product

Resources

About