Planetary wave-driven enhanced NO descent into the top of the Arctic polar vortex during major and minor SSWs

Abstract. It is well established that variable wintertime planetary wave forcing in the stratosphere controls the variability of Arctic stratospheric ozone through changes in the strength of the polar vortex and the residual circulation. While previous studies focused on the variations in upward wave flux entering the lower stratosphere, here the impact of downward planetary wave reflection on ozone is investigated for the first time. Utilizing the MERRA2 reanalysis and a fully coupled chemistry–climate simulation with the Community Earth System Model (CESM1(WACCM)) of the National Center for Atmospheric Research (NCAR), we find two downward wave reflection effects on ozone: (1) the direct effect in which the residual circulation is weakened during winter, reducing the typical increase of ozone due to upward planetary wave events and (2) the indirect effect in which the modification of polar temperature during winter affects the amount of ozone destruction in spring. Winter seasons dominated by downward wave reflection events (i.e., reflective winters) are characterized by lower Arctic ozone concentration, while seasons dominated by increased upward wave events (i.e., absorptive winters) are characterized by relatively higher ozone concentration. This behavior is consistent with the cumulative effects of downward and upward planetary wave events on polar stratospheric ozone via the residual circulation and the polar temperature in winter. The results establish a new perspective on dynamical processes controlling stratospheric ozone variability in the Arctic by highlighting the key role of wave reflection.

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Preconditioning of Arctic Stratospheric Polar Vortex Shift Events

Journal of Climate ◽

10.1175/jcli-d-17-0695.1 ◽

2018 ◽

Vol 31 (14) ◽

pp. 5417-5436 ◽

Cited By ~ 11

Author(s):

Jinlong Huang ◽

Wenshou Tian ◽

Lesley J. Gray ◽

Jiankai Zhang ◽

Yan Li ◽

...

Keyword(s):

North America ◽

North Atlantic ◽

Planetary Wave ◽

Polar Vortex ◽

The Arctic ◽

Bering Strait ◽

Surface Cooling ◽

Stratospheric Polar Vortex ◽

Significant Difference ◽

Eastern North Atlantic

Abstract This study examines the preconditioning of events in which the Arctic stratospheric polar vortex shifts toward Eurasia (EUR events), North America (NA events), and the Atlantic (ATL events) using composite analysis. An increase in blocking days over northern Europe and a decrease in blocking days over the Bering Strait favor the movement of the vortex toward Eurasia, while the opposite changes in blocking days over those regions favor the movement of the vortex toward North America. An increase in blocking days over the eastern North Atlantic and a decrease in blocking days over the Bering Strait are conducive to movement of the stratospheric polar vortex toward the Atlantic. These anomalous precursor blocking patterns are interpreted in terms of the anomalous zonal wave-1 or wave-2 planetary wave fluxes into the stratosphere that are known to influence the vortex position and strength. In addition, the polar vortex shift events are further classified into events with small and large polar vortex deformation, since the two types of events are likely to have a different impact at the surface. A significant difference in the zonal wave-2 heat flux into the lower stratosphere exists prior to the two types of events and this is linked to anomalous blocking patterns. This study further defines three types of tropospheric blocking events in which the spatial patterns of blocking frequency anomalies are similar to the blocking patterns prior to EUR, NA, and ATL events, respectively, and our reanalysis reveals that the polar vortex is indeed more likely to shift toward Eurasia, North America, and the Atlantic in the presence of the above three defined tropospheric blocking events. These shifts of the polar vortex toward Eurasia, North America, and the Atlantic lead to statistically significant negative height anomalies near the tropopause and corresponding surface cooling anomalies over these three regions.

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How Does Downward Planetary Wave Coupling Affect Polar Stratospheric Ozone in the Arctic Winter Stratosphere?

10.5194/acp-2016-558 ◽

2016 ◽

Author(s):

Sandro W. Lubis ◽

Vered Silverman ◽

Katja Matthes ◽

Nili Harnik ◽

Nour-Eddine Omrani ◽

...

Keyword(s):

Ozone Concentration ◽

Planetary Wave ◽

Stratospheric Ozone ◽

Polar Vortex ◽

The Arctic ◽

Climate Simulation ◽

Residual Circulation ◽

Wave Coupling ◽

Wave Flux ◽

The Impact

Abstract. It is well established that variable wintertime planetary wave forcing in the stratosphere controls the variability of Arctic stratospheric ozone through changes in the strength of the polar vortex and the residual circulation. While previous studies focused on the variations in upward wave flux entering the lower stratosphere, here the impact of downward planetary wave coupling (DWC) on ozone is investigated for the first time. Utilizing the MERRA-2 reanalysis and a fully coupled chemistry-climate simulation with NCAR's Community Earth System Model (CESM1[WACCM]), we find two DWC effects on ozone: (1) the direct effect in which the residual circulation is modified and prevents the typical increase of ozone due to upward planetary wave events in winter, and (2) the indirect effect in which the modification of polar temperature during winter affects the amount of ozone destruction in spring. Winter seasons dominated by DWC events (i.e., reflective winters) are characterized by lower Arctic ozone concentration, while seasons dominated by increased upward wave events (i.e., absorptive winters) are characterized by relatively higher ozone concentration. This behavior is consistent with the cumulative effects of downward and upward planetary wave events on polar stratospheric ozone via the residual circulation and the polar temperature in winter. The results establish a new perspective on dynamical processes controlling stratospheric ozone variability in the Arctic.

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Stratosphere–Troposphere Coupling and Links with Eurasian Land Surface Variability

Journal of Climate ◽

10.1175/2007jcli1725.1 ◽

2007 ◽

Vol 20 (21) ◽

pp. 5335-5343 ◽

Cited By ~ 201

Author(s):

Judah Cohen ◽

Mathew Barlow ◽

Paul J. Kushner ◽

Kazuyuki Saito

Keyword(s):

Land Surface ◽

Planetary Wave ◽

Vertical Component ◽

Polar Vortex ◽

Subsequent Development ◽

Wave Activity ◽

The Arctic ◽

Surface Circulation ◽

The Arctic Oscillation ◽

Hemisphere Winter

Abstract A diagnostic of Northern Hemisphere winter extratropical stratosphere–troposphere interactions is presented to facilitate the study of stratosphere–troposphere coupling and to examine what might influence these interactions. The diagnostic is a multivariate EOF combining lower-stratospheric planetary wave activity flux in December with sea level pressure in January. This EOF analysis captures a strong linkage between the vertical component of lower-stratospheric wave activity over Eurasia and the subsequent development of hemisphere-wide surface circulation anomalies, which are strongly related to the Arctic Oscillation. Wintertime stratosphere–troposphere events picked out by this diagnostic often have a precursor in autumn: years with large October snow extent over Eurasia feature strong wintertime upward-propagating planetary wave pulses, a weaker wintertime polar vortex, and high geopotential heights in the wintertime polar troposphere. This provides further evidence for predictability of wintertime circulation based on autumnal snow extent over Eurasia. These results also raise the question of how the atmosphere will respond to a modified snow cover in a changing climate.

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Extratropical Ocean Warming and Winter Arctic Sea Ice Cover since the 1990s

Journal of Climate ◽

10.1175/jcli-d-14-00629.1 ◽

2015 ◽

Vol 28 (14) ◽

pp. 5510-5522 ◽

Cited By ~ 18

Author(s):

Fei Li ◽

Huijun Wang ◽

Yongqi Gao

Keyword(s):

Heat Flux ◽

Wave Propagation ◽

Sea Ice ◽

Planetary Wave ◽

Polar Vortex ◽

Arctic Sea Ice ◽

The Arctic ◽

Arctic Sea ◽

Planetary Wave Propagation ◽

Sst Anomalies

Abstract Despite the fact that the Arctic Oscillation (AO) has reached a more neutral state and a global-warming hiatus has occurred in winter since the late 1990s, the Arctic sea ice cover (ASIC) still shows a pronounced decrease. This study reveals a close connection (R = 0.5) between the extratropical sea surface temperature (ET-SST) and ASIC in winter from 1994 to 2013. In response to one positive (negative) unit of deviation in the ET-SST pattern, the ASIC decreases (increases) in the Barents–Kara Seas and Hudson Bay (the Baffin Bay and Bering Sea) by 100–400 km2. This relationship might be maintained because of the impact of warming extratropical oceans on the polar vortex. Positive SST anomalies in the midlatitudes of the North Pacific and Atlantic (around 40°N) strengthen the equatorward planetary wave propagation, whereas negative SST anomalies in the high latitudes weaken the upward planetary wave propagation from the lower troposphere to the stratosphere. The former indicates a strengthening of the poleward meridional eddy momentum flux, and the latter implies a weakening of the poleward eddy heat flux, which favors an intensified upper-level polar night jet and a colder polar vortex, implying a stronger-than-normal polar vortex. Consequently, an anomalous cyclone emerges over the eastern Arctic, limiting or encouraging the ASIC by modulating the mean meridional heat flux. A possible reason for the long-term changes in the relationship between the ET-SST and ASIC is also discussed.

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Tropospheric forcing of the boreal polar vortex splitting in January 2003

Annales Geophysicae ◽

10.5194/angeo-28-2133-2010 ◽

2010 ◽

Vol 28 (11) ◽

pp. 2133-2148 ◽

Cited By ~ 9

Author(s):

D. H. W. Peters ◽

P. Vargin ◽

A. Gabriel ◽

N. Tsvetkova ◽

V. Yushkov

Keyword(s):

Rossby Wave ◽

Planetary Wave ◽

Winter Season ◽

Polar Vortex ◽

Wave Activity ◽

The Arctic ◽

Stratospheric Warming ◽

Sudden Stratospheric Warming ◽

Stratospheric Polar Vortex ◽

Wave Trains

Abstract. The dynamical evolution of the relatively warm stratospheric winter season 2002–2003 in the Northern Hemisphere was studied and compared with the cold winter 2004–2005 based on NCEP-Reanalyses. Record low temperatures were observed in the lower and middle stratosphere over the Arctic region only at the beginning of the 2002–2003 winter. Six sudden stratospheric warming events, including the major warming event with a splitting of the polar vortex in mid-January 2003, have been identified. This led to a very high vacillation of the zonal mean circulation and a weakening of the stratospheric polar vortex over the whole winter season. An estimate of the mean chemical ozone destruction inside the polar vortex showed a total ozone loss of about 45 DU in winter 2002–2003; that is about 2.5 times smaller than in winter 2004–2005. Embedded in a winter with high wave activity, we found two subtropical Rossby wave trains in the troposphere before the major sudden stratospheric warming event in January 2003. These Rossby waves propagated north-eastwards and maintained two upper tropospheric anticyclones. At the same time, the amplification of an upward propagating planetary wave 2 in the upper troposphere and lower stratosphere was observed, which could be caused primarily by those two wave trains. Furthermore, two extratropical Rossby wave trains over the North Pacific Ocean and North America were identified a couple of days later, which contribute mainly to the vertical planetary wave activity flux just before and during the major warming event. It is shown that these different tropospheric forcing processes caused the major warming event and contributed to the splitting of the polar vortex.

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The Diurnal Variation in Stratospheric Ozone from MACC Reanalysis, ERA-Interim, WACCM, and Earth Observation Data: Characteristics and Intercomparison

Atmosphere ◽

10.3390/atmos12050625 ◽

2021 ◽

Vol 12 (5) ◽

pp. 625

Author(s):

Ansgar Schanz ◽

Klemens Hocke ◽

Niklaus Kämpfer ◽

Simon Chabrillat ◽

Antje Inness ◽

...

Keyword(s):

Diurnal Variation ◽

Climate Model ◽

Stratospheric Ozone ◽

Polar Vortex ◽

Model Systems ◽

Atmospheric Composition ◽

The Arctic ◽

Observation Data ◽

High Latitudes ◽

Free Running

In this study, we compare the diurnal variation in stratospheric ozone of the MACC (Monitoring Atmospheric Composition and Climate) reanalysis, ECMWF Reanalysis Interim (ERA-Interim), and the free-running WACCM (Whole Atmosphere Community Climate Model). The diurnal variation of stratospheric ozone results from photochemical and dynamical processes depending on altitude, latitude, and season. MACC reanalysis and WACCM use similar chemistry modules and calculate a similar diurnal cycle in ozone when it is caused by a photochemical variation. The results of the two model systems are confirmed by observations of the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) experiment and three selected sites of the Network for Detection of Atmospheric Composition Change (NDACC) at Mauna Loa, Hawaii (tropics), Bern, Switzerland (midlatitudes), and Ny-Ålesund, Svalbard (high latitudes). On the other hand, the ozone product of ERA-Interim shows considerably less diurnal variation due to photochemical variations. The global maxima of diurnal variation occur at high latitudes in summer, e.g., near the Arctic NDACC site at Ny-Ålesund, Svalbard. The local OZORAM radiometer observes this effect in good agreement with MACC reanalysis and WACCM. The sensed diurnal variation at Ny-Ålesund is up to 8% (0.4 ppmv) due to photochemical variations in summer and negligible during the dynamically dominated winter. However, when dynamics play a major role for the diurnal ozone variation as in the lower stratosphere (100–20 hPa), the reanalysis models ERA-Interim and MACC which assimilate data from radiosondes and satellites outperform the free-running WACCM. Such a domain is the Antarctic polar winter where a surprising novel feature of diurnal variation is indicated by MACC reanalysis and ERA-Interim at the edge of the polar vortex. This effect accounts for up to 8% (0.4 ppmv) in both model systems. In summary, MACC reanalysis provides a global description of the diurnal variation of stratospheric ozone caused by dynamics and photochemical variations. This is of high interest for ozone trend analysis and other research which is based on merged satellite data or measurements at different local time.

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Chemical ozone loss and ozone mini-hole event during the Arctic winter 2010/2011 as observed by SCIAMACHY and GOME-2

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-3247-2014 ◽

2014 ◽

Vol 14 (7) ◽

pp. 3247-3276 ◽

Cited By ~ 16

Author(s):

R. Hommel ◽

K.-U. Eichmann ◽

J. Aschmann ◽

K. Bramstedt ◽

M. Weber ◽

...

Keyword(s):

Transport Model ◽

Polar Vortex ◽

The Arctic ◽

Optical Absorption Spectroscopy ◽

Late Winter ◽

Total Column Ozone ◽

Bromine Oxide ◽

Ozone Loss ◽

Catalytic Cycles ◽

Total Column

Abstract. Record breaking loss of ozone (O3) in the Arctic stratosphere has been reported in winter–spring 2010/2011. We examine in detail the composition and transformations occurring in the Arctic polar vortex using total column and vertical profile data products for O3, bromine oxide (BrO), nitrogen dioxide (NO2), chlorine dioxide (OClO), and polar stratospheric clouds (PSC) retrieved from measurements made by SCIAMACHY (Scanning Imaging Absorption SpectroMeter for Atmospheric CHartography) on-board Envisat (Environmental Satellite), as well as total column ozone amount, retrieved from the measurements of GOME-2 (Global Ozone Monitoring Experiment) on MetOp-A (Meteorological Experimental Satellite). Similarly we use the retrieved data from DOAS (Differential Optical Absorption Spectroscopy) measurements made in Ny-Ålesund (78.55° N, 11.55° E). A chemical transport model (CTM) has been used to relate and compare Arctic winter–spring conditions in 2011 with those in the previous year. In late winter–spring 2010/2011 the chemical ozone loss in the polar vortex derived from SCIAMACHY observations confirms findings reported elsewhere. More than 70% of O3 was depleted by halogen catalytic cycles between the 425 and 525 K isentropic surfaces, i.e. in the altitude range ~16–20 km. In contrast, during the same period in the previous winter 2009/2010, a typical warm Arctic winter, only slightly more than 20% depletion occurred below 20 km, while 40% of O3 was removed above the 575 K isentrope (~23 km). This loss above 575 K is explained by the catalytic destruction by NOx descending from the mesosphere. In both Arctic winters 2009/2010 and 2010/2011, calculated O3 losses from the CTM are in good agreement to our observations and other model studies. The mid-winter 2011 conditions, prior to the catalytic cycles being fully effective, are also investigated. Surprisingly, a significant loss of O3 around 60%, previously not discussed in detail, is observed in mid-January 2011 below 500 K (~19 km) and sustained for approximately 1 week. The low O3 region had an exceptionally large spatial extent. The situation was caused by two independently evolving tropopause elevations over the Asian continent. Induced adiabatic cooling of the stratosphere favoured the formation of PSC, increased the amount of active chlorine for a short time, and potentially contributed to higher polar ozone loss later in spring.

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The Arctic vortex in March 2011: a dynamical perspective

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-11447-2011 ◽

2011 ◽

Vol 11 (22) ◽

pp. 11447-11453 ◽

Cited By ~ 47

Author(s):

M. M. Hurwitz ◽

P. A. Newman ◽

C. I. Garfinkel

Keyword(s):

Planetary Wave ◽

La Niña ◽

The Arctic ◽

Late Winter ◽

Quasi Biennial Oscillation ◽

The North ◽

La Nina ◽

Sea Surface Temperature Anomalies ◽

Biennial Oscillation ◽

The North Pacific

Abstract. Despite the record ozone loss observed in March 2011, dynamical conditions in the Arctic stratosphere were unusual but not unprecedented. Weak planetary wave driving in February preceded cold anomalies in the polar lower stratosphere in March and a relatively late breakup of the Arctic vortex in April. La Niña conditions and the westerly phase of the quasi-biennial oscillation (QBO) were observed in March 2011. Though these conditions are generally associated with a stronger vortex in mid-winter, the respective cold anomalies do not persist through March. Therefore, the La Niña and QBO-westerly conditions cannot explain the observed cold anomalies in March 2011. In contrast, positive sea surface temperature anomalies in the North Pacific may have contributed to the unusually weak tropospheric wave driving and strong Arctic vortex in late winter 2011.

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Volcanic activity sparks the Arctic Oscillation

Scientific Reports ◽

10.1038/s41598-021-94935-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Weizheng Qu ◽

Fei Huang ◽

Jinping Zhao ◽

Ling Du ◽

Yong Cao

Keyword(s):

Volcanic Activity ◽

Volcanic Eruption ◽

Arctic Oscillation ◽

Polar Vortex ◽

Volcanic Eruptions ◽

The Arctic ◽

Vortex System ◽

Significant Fluctuation ◽

The Arctic Oscillation

AbstractThe parasol effect of volcanic dust and aerosol caused by volcanic eruption results in the deepening and strengthening of the Arctic vortex system, thus stimulating or strengthening the Arctic Oscillation (AO). Three of the strongest AOs in more than a century have been linked to volcanic eruptions. Every significant fluctuation of the AO index (AOI = ΔH_middle latitudes − ΔH_Arctic) for many years has been associated with a volcanic eruption. Volcanic activity occurring at different locations in the Arctic vortex circulation will exert different effects on the polar vortex.

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