The Antarctic Atmospheric Energy Budget. Part I: Climatology and Intraseasonal-to-Interannual Variability

Previdi, Michael; Smith, Kay; Polvani, Lorenzo M.

doi:10.1175/jcli-d-12-00640.1

Cited by 14 publications

(9 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In response to twenty‐first century stratospheric ozone recovery, the CESM1 projects an increase in the net incoming radiation at the TOA during most months of the year, with the largest increases occurring during austral spring (Figure (a)). In order to maintain atmospheric energy balance, changes in the TOA radiation over the Antarctic tend to be compensated, on annual and longer time‐scales, by changes in the atmospheric energy‐flux convergence (Previdi et al , ; Smith et al , ). In accordance with this, decreases in the energy flux convergence over the polar cap are simulated throughout most of the year (Figure (c)), with the largest decreases lagging the largest increases in the TOA radiation by 2–3 months.…”

Section: Climate‐system Response To Stratospheric Ozone Recoverymentioning

confidence: 99%

Climate system response to stratospheric ozone depletion and recovery

Previdi

Polvani

2014

Quart J Royal Meteoro Soc

Self Cite

153

117

View full text Add to dashboard Cite

We review what is presently known about the climate system response to stratospheric ozone depletion and its projected recovery, focusing on the responses of the atmosphere, ocean and cryosphere. Compared with well‐mixed greenhouse gases (GHGs), the radiative forcing of climate due to observed stratospheric ozone loss is very small: in spite of this, recent trends in stratospheric ozone have caused profound changes in the Southern Hemisphere (SH) climate system, primarily by altering the tropospheric midlatitude jet, which is commonly described as a change in the Southern Annular Mode. Ozone depletion in the late twentieth century was the primary driver of the observed poleward shift of the jet during summer, which has been linked to changes in tropospheric and surface temperatures, clouds and cloud radiative effects, and precipitation at both middle and low latitudes. It is emphasized, however, that not all aspects of the SH climate response to stratospheric ozone forcing can be understood in terms of changes in the midlatitude jet. The response of the Southern Ocean and sea ice to ozone depletion is currently a matter of debate. For the former, the debate is centred on the role of ocean eddies in possibly opposing wind‐driven changes in the mean circulation. For the latter, the issue is reconciling the observed expansion of Antarctic sea‐ice extent during the satellite era with robust modelling evidence that the ice should melt as a result of stratospheric ozone depletion (and increases in GHGs). Despite lingering uncertainties, it has become clear that ozone depletion has been instrumental in driving SH climate change in recent decades. Similarly, ozone recovery will figure prominently in future climate change, with its impacts expected to largely cancel the impacts of increasing GHGs during the next half‐century.

show abstract

Section: Climate‐system Response To Stratospheric Ozone Recoverymentioning

confidence: 99%

Climate system response to stratospheric ozone depletion and recovery

Previdi

Polvani

2014

Quart J Royal Meteoro Soc

Self Cite

153

117

View full text Add to dashboard Cite

show abstract

“…The air loses energy through transfer toward the ice-sheet surface and via the emission of longwave radiation to space (Previdi et al, 2013). This climatological energy deficit is mainly compensated by a horizontal convergence of atmospheric energy transport (Genthon & Krinner, 1998;Previdi et al, 2013). The near-surface Antarctic atmosphere experienced significant changes during the last decades (Steig et al, 2009;Turner et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

“…As such, it is critical to understand the atmospheric heat exchanges over the white continent in the context of global warming. The air loses energy through transfer toward the ice‐sheet surface and via the emission of longwave radiation to space (Previdi et al, ). This climatological energy deficit is mainly compensated by a horizontal convergence of atmospheric energy transport (Genthon & Krinner, ; Previdi et al, ).…”

Section: Introductionmentioning

confidence: 99%

Modeling the Dynamics of the Atmospheric Boundary Layer Over the Antarctic Plateau With a General Circulation Model

Vignon

Hourdin

Genthon

et al. 2018

J Adv Model Earth Syst

View full text Add to dashboard Cite

Observations evidence extremely stable boundary layers (SBL) over the Antarctic Plateau and sharp regime transitions between weakly and very stable conditions. Representing such features is a challenge for climate models. This study assesses the modeling of the dynamics of the boundary layer over the Antarctic Plateau in the LMDZ general circulation model. It uses 1 year simulations with a stretched‐grid over Dome C. The model is nudged with reanalyses outside of the Dome C region such as simulations can be directly compared to in situ observations. We underline the critical role of the downward longwave radiation for modeling the surface temperature. LMDZ reasonably represents the near‐surface seasonal profiles of wind and temperature but strong temperature inversions are degraded by enhanced turbulent mixing formulations. Unlike ERA‐Interim reanalyses, LMDZ reproduces two SBL regimes and the regime transition, with a sudden increase in the near‐surface inversion with decreasing wind speed. The sharpness of the transition depends on the stability function used for calculating the surface drag coefficient. Moreover, using a refined vertical grid leads to a better reversed “S‐shaped” relationship between the inversion and the wind. Sudden warming events associated to synoptic advections of warm and moist air are also well reproduced. Near‐surface supersaturation with respect to ice is not allowed in LMDZ but the impact on the SBL structure is moderate. Finally, climate simulations with the free model show that the recommended configuration leads to stronger inversions and winds over the ice‐sheet. However, the near‐surface wind remains underestimated over the slopes of East‐Antarctica.

show abstract

“…The positive polarity of the SAM is associated with anomalously warm conditions across the Antarctic Peninsula and generally cool conditions across East Antarctica and much of West Antarctica [e.g., Thompson and Solomon , ; Kwok and Comiso , ; Marshall , ]. The cooler surface air temperatures (SATs) over East Antarctica are consistent with reduced poleward advection of heat and moisture [ Previdi et al ., ] and a weakening of the strength of katabatic winds over the continent [ van den Broeke and van Lipzig , ; Marshall et al ., ]. Conversely, the warmer SATs over the Peninsula are consistent with anomalous onshore flow of warm maritime air into the Peninsula region associated with a deeper Amundsen Sea Low [ Fogt et al ., ; Hosking et al ., ; Raphael et al ., ], which forms a marked nonannular component to the SAM west of the Peninsula [e.g., Fogt et al ., ].…”

Section: Introductionmentioning

confidence: 99%

The signatures of large‐scale patterns of atmospheric variability in Antarctic surface temperatures

2016

View full text Add to dashboard Cite

We investigate the impact that the four principal large-scale patterns of Southern Hemisphere (SH) atmospheric circulation variability have on Antarctic surface air temperature (SAT): (1) the southern baroclinic annular mode (BAM), which is associated with variations in extratropical storm amplitude; (2) the Southern Annular Mode (SAM), associated with latitudinal shifts in the midlatitude jet; and (3) the two Pacific-South American patterns (PSA1 and PSA2), which are characterized by wave trains originating in the tropical Pacific that extend across the SH extratropics. A key aspect is the use of 35 years of daily observations and reanalysis data, which affords a sufficiently large sample size to assess the signatures of the circulation patterns in both the mean and variability of daily mean SAT anomalies. The BAM exerts the weakest influence on Antarctic SAT, albeit it is still important over select regions. Consistent with previous studies, the SAM is shown to influence SAT across most of the continent throughout the year. The PSA1 also affects SAT across almost all of Antarctica. Regionally, both PSA patterns can exert a greater impact on SAT than the SAM but also have a significantly weaker influence during summer, reflecting the seasonality of the SH response to El Niño-Southern Oscillation. The SAM and PSA patterns have distinct signatures in daily SAT variance that are physically consistent with their signatures in extratropical dynamic variability. The broad-scale climate linkages identified here provide benchmarks for interpreting the Antarctic climate response to future changes in tropical sea surface temperatures, ozone recovery, and greenhouse gas increases.

show abstract

The Antarctic Atmospheric Energy Budget. Part I: Climatology and Intraseasonal-to-Interannual Variability

Cited by 14 publications

References 45 publications

Climate system response to stratospheric ozone depletion and recovery

Climate system response to stratospheric ozone depletion and recovery

Modeling the Dynamics of the Atmospheric Boundary Layer Over the Antarctic Plateau With a General Circulation Model

The signatures of large‐scale patterns of atmospheric variability in Antarctic surface temperatures

Contact Info

Product

Resources

About