Satellite Observations of SST‐Induced Wind Speed Perturbation at the Oceanic Submesoscale

Gaube, Peter; Chickadel, C. Chris; Branch, Ruth; Jessup, Andrew T.

doi:10.1029/2018gl080807

Cited by 22 publications

(21 citation statements)

References 17 publications

(31 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These results contribute to the recent advances in the study of the effects that both permanent and transient spatial SST structures have on the marine atmospheric boundary layer. As mentioned above, despite the existence of a negative correlation between large‐scale wind speed and SST, a modulation of wind velocity is found in the presence of the thermal signatures of oceanic structures at the mesoscale and submesoscale (Chelton et al., 2004; Laurindo et al., 2019; Gaube et al., 2019; Shao et al., 2019).…”

Section: Surface Ocean Sst Structures Contribute To Small‐scale Atmosmentioning

confidence: 99%

Air‐Sea Interactions in the Cold Wakes of Tropical Cyclones

Pasquero

Desbiolles

Meroni

2021

Geophysical Research Letters

View full text Add to dashboard Cite

The climate system is composed of different compartments which communicate and exchange properties at their boundaries, such as at the air-sea interface, modifying momentum, gas concentrations, heat, and moisture content. The air-sea fluxes depend on the thermal, chemical, and dynamical disequilibrium between the upper ocean and the lower atmosphere. Despite being crucial for both weather and climate phenomena, their observations are still challenging, especially at high-spatiotemporal resolution (Cronin et al., 2019; Gentemann et al., 2020). Air-sea fluxes are enhanced in presence of strong winds, which favor the vertical mixing both in the atmosphere and in the ocean, inhibiting the formation of a very shallow interface layer in quasi-equilibrium conditions that would limit further exchanges. Strong winds increase sensible heat flux and evaporation from the ocean into the atmosphere and input momentum into the upper ocean, generating turbulence that deepens the oceanic mixed layer. Both processes tend to reduce the sea surface temperature (SST). Atmospheric internal dynamics generates variability in the surface winds at the synoptic scale (O(1,000 km) and more), driving an upper ocean response that results in a widespread negative correlation between largescale winds and SST (see Figure 1a, the positive correlation in the eastern equatorial Pacific is due to the dynamics of El Niño Southern Oscillation, which is a fully coupled phenomenon). At smaller scales, the negative correlation disappears (see Figure 1b), indicating that winds no longer drive ocean surface conditions but rather are affected by SST mesoscale and submesoscale variability (O(100s km) and less). The scale separation between the two behaviors is thus related to the scale of the instabilities that generate balanced structures in the two media. Tropical cyclones are atmospheric phenomena with a size of O(100s km), in between atmospheric synoptic scales and oceanic mesoscales. They both affect and are affected by the SST

show abstract

Section: Surface Ocean Sst Structures Contribute To Small‐scale Atmosmentioning

confidence: 99%

Air‐Sea Interactions in the Cold Wakes of Tropical Cyclones

Pasquero

Desbiolles

Meroni

2021

Geophysical Research Letters

View full text Add to dashboard Cite

show abstract

“…Due to the dynamic coupling of the atmosphere and ocean, the influence of transient, mesoscale structures at the ocean surface effectively creates an imprint of the upper ocean on the MABL (Frenger et al, 2013;Small et al, 2008). A similar process may also occur at the submesoscale regime (Gaube et al, 2019). Submesoscale fronts (SFs), one kind of oceanic submesoscale phenomena, can be detected by their surface expression.…”

Section: Research Articlementioning

confidence: 99%

“…The assumed logarithmic vertical profile of wind speed indicates that there is a strong velocity gradient within the ASL, which produces the most energetic air‐sea fluxes occurring in the MABL. The variability of the log layer across SF is unknown from previous aircraft measurements (Vickers & Mahrt, ) and satellite observation (Gaube et al, ).…”

Section: Introductionmentioning

confidence: 99%

The Variability of Winds and Fluxes Observed Near Submesoscale Fronts

et al. 2019

View full text Add to dashboard Cite

Submesoscale oceanic fronts (SFs), which typically occur on a spatial scale of 0.1-10 km, may have a large influence on the atmospheric surface layer (ASL). However, due to their short temporal-spatial scales, evaluating their direct impact on this layer remains challenging and characterizing the nature of SF-ASL interaction has not been done in the field. To address this, a study of the air-sea response to SFs was conducted using observations collected during the Lagrangian Submesoscale Experiment, which took place in the northern Gulf of Mexico. This manuscript focuses on the meteorological measurements made from a pair of masts installed on the bow of the R/V Walton Smith. This work represents one of the first observation-based investigations into the potential influence that SFs have on the ASL. Contemporaneous measurements from an X-band marine radar, moving vessel profiler, and Lagrangian drifters were also used to analyze the SF dynamics. Systematic surface wind velocity changes over several cross-frontal transects were observed, a process previously associated with mesoscale fronts. A comparison between the eddy covariance and parameterized (COARE 3.5) air-sea fluxes revealed that the directly observed heat flux was 1.5 times larger than the bulk value in the vicinity of the SFs. This suggests that the hydrodynamic processes near the front enhance the local exchange of sensible and latent heat. Given the prevalence of SF over the global upper ocean, these findings suggest that these features may have a widely distributed and cumulative impact on air-sea interactions. Plain Language SummaryThe atmosphere responds to the ocean over all scales-from microscopic to planetary scales. Previous studies showed that surface wind and even the entire atmospheric boundary layer could be affected by the relatively large-scale (10-1,000 km) temperature variations across the open ocean, for example, the Gulf Stream. However, the impacts of relatively small-scale (100 m to 10 km) and rapidly (hours to days) evolving fronts are largely unknown due to the difficulty in actually observing the physical processes. As part of an ongoing effort to better understand surface material dispersion across the northern Gulf of Mexico, we conducted ship-based measurements of air-sea fluxes across near small-scale fronts. The observations showed that the physical mechanism used to explain the interaction between the atmosphere and large-scale ocean temperature gradients readily downscales to these smaller fronts, which have a direct impact of wind directly above the ocean surface. These small-scale fronts were also observed to locally enhance the air-sea heat flux, and the conventional model used to predict this underestimates the observed value by as much as 50%. These small-scale frontal features are common across the global ocean, and our findings suggest that they could cumulatively impact the global energy budget.

show abstract

“…(), Seo (), and Gaube et al . (). The latter find evidence of the SST–wind relationship at kilometric and sub‐kilometric spatial scales, with cutting‐edge satellite measurements of wind speed and SST from a case‐study along the Gulf Stream frontal system.…”

Section: Introductionmentioning

confidence: 97%

Observational evidence of the preferential occurrence of wind convergence over sea surface temperature fronts in the Mediterranean

Meroni

Giurato

Ragone

et al. 2020

Quart J Royal Meteoro Soc

View full text Add to dashboard Cite

Air and sea interact on a wide range of scales, shaping climate and influencing weather. The direct effect of sea surface temperature (SST) structures on the extratropical atmosphere at the daily time-scale is generally masked by the large variability associated with atmospheric dynamics. With 25 years of daily SST and surface wind observational products, obtained with data from buoys, satellite and atmospheric analysis in the Mediterranean, we show that strong surface wind convergence preferentially occurs when the air encounters a cold SST front. The mechanism responsible for the influence of ocean fronts on surface winds is rooted in the thermal disequilibrium that emerges at the air-sea interface, where cold water enhances the stability of the boundary layer, decoupling surface winds from the stronger winds aloft. Surface convergence drives upward motion which, under appropriate conditions, favours cloud formation. Thus, these results suggest that weather forecast models need to properly represent the small-scale ocean thermal structures, which could affect rainfall. K E Y W O R D Sair-sea interactions, climatology, wind response

show abstract

Satellite Observations of SST‐Induced Wind Speed Perturbation at the Oceanic Submesoscale

Cited by 22 publications

References 17 publications

Air‐Sea Interactions in the Cold Wakes of Tropical Cyclones

Air‐Sea Interactions in the Cold Wakes of Tropical Cyclones

The Variability of Winds and Fluxes Observed Near Submesoscale Fronts

Observational evidence of the preferential occurrence of wind convergence over sea surface temperature fronts in the Mediterranean

Contact Info

Product

Resources

About