Role of Ocean and Atmosphere Variability in Scale‐Dependent Thermodynamic Air‐Sea Interactions

Abstract

This study investigates the influence of oceanic and atmospheric processes in extratropical thermodynamic air‐sea interactions resolved by satellite observations (OBS) and by two climate model simulations run with eddy‐resolving high‐resolution (HR) and eddy‐parameterized low‐resolution (LR) ocean components. Here, spectral methods are used to characterize the sea surface temperature (SST) and turbulent heat flux (THF) variability and co‐variability over scales between 50 and 10,000 km and 60 days to 80 years in the Pacific Ocean. The relative roles of the ocean and atmosphere are interpreted using a stochastic upper‐ocean temperature evolution model forced by noise terms representing intrinsic variability in each medium, defined using climate model data to produce realistic rather than white spectral power density distributions. The analysis of all datasets shows that the atmosphere dominates the SST and THF variability over zonal wavelengths larger than ∼2,000–2,500 km. In HR and OBS, ocean processes dominate the variability of both quantities at scales smaller than the atmospheric first internal Rossby radius of deformation (R1, ∼600–2,000 km) due to a substantial ocean forcing coinciding with a weaker atmospheric modulation of THF (and consequently of SST) than at larger scales. The ocean forcing also induces oscillations in SST and THF with periods ranging from intraseasonal to multidecadal, reflecting a red spectrum response to ocean forcing similar to that driven by atmospheric forcing. Such features are virtually absent in LR due to a weaker ocean forcing relative to HR.

Effect of Oceanic Stochastic Forcing on Wintertime Atmospheric Decadal Variability Over Midlatitude North Pacific

“…The possible reason may reside in the dependence on the principal variability of atmospheric background state as well as the energy cascade between the high frequency of oceanic stochastic forcing and the low frequency of PDO (Blackmon, Lee, Wallace, 1984; Blackmon, Lee, Wallace, & Hsu, 1984; Hendon & Hartmann, 1985) which help to increase and maintain the observed prominent decadal variability over the west of North Pacific (Figure 3). Several recent works also have shown that mesoscale eddies influence spatial scales of atmospheric variability larger than the scales of the eddies themselves at monthly‐to‐interannual and even longer timescales (Chang et al., 2020; Constantinou & Hogg, 2021; Kirtman et al., 2012; Laurindo et al., 2022; Martin et al., 2021; Patrizio & Thompson, 2022; Xiaoshan Sun & Wu, 2021, 2022).…”

“…The mesoscale SSTAs can influence the large‐scale air‐sea interaction (Bishop et al., 2017; Laurindo et al., 2022; Martin et al., 2021; Small, Bryan, et al., 2019; Xiaoshan Sun & Wu, 2022). On one hand, mesoscale SSTAs usually appear as groups, and they are widely distributed in the mid‐to‐high latitude ocean regions (Chelton, Gaube, et al., 2011; Chelton, Schlax, & Samelson, 2011; Early et al., 2011; H. Hu et al., 2021; Itoh & Yasuda, 2010; Zhang et al., 2019).…”

Small‐Scale Spatial Variations of Air‐Sea Heat, Moisture, and Buoyancy Fluxes in the Tropical Trade Winds

“…Global and regional climate models that resolve mesoscale ocean features show a stronger influence of ocean variability on air‐sea interaction (Laurindo et al., 2022) and have reduced biases compared to lower‐resolution models (Bryan et al., 2010; R. J. Small et al., 2014; Su et al., 2018), including in the tropical Atlantic (Seo et al., 2006).…”

“…This can also be the case away from regions with coherent ocean mesoscale activity. Global and regional climate models that resolve mesoscale ocean features show a stronger influence of ocean variability on air-sea interaction (Laurindo et al, 2022) and have reduced biases compared to lower-resolution models (Bryan et al, 2010;R. J.…”

Quantifying the Contribution of Ocean Advection and Surface Flux to the Upper‐Ocean Salinity Variability Resolved by Climate Model Simulations

“…Mesoscale ocean currents play a significant role in setting the upper‐ocean temperature variability over much of the extratropical oceans. Indeed, estimates based on observations and model simulations indicate that the heat flux convergence associated with the mesoscale ocean eddy variability dominates over other terms of the heat budget equation at spatial scales smaller than about 1,000 km and timescales ranging from intraseasonal to interannual (e.g., Martin et al., 2021; Patrizio & Thompson, 2021, 2022; Putrasahan et al., 2017; Small et al., 2020) and potentially longer (Laurindo et al., 2022). While the conclusions drawn for the upper‐ocean temperature suggest that advection by transient ocean motions can also be relevant for driving the upper‐ocean salinity variability, only regional assessments of salinity have been made, and they show contrasting conclusions on the role of advection.…”