Jump to content

Sudden stratospheric warming

From Wikipedia, the free encyclopedia

A sudden stratospheric warming (SSW) is an event in which polar stratospheric temperatures rise by several tens of kelvins (up to increases of about 50 °C (90 °F)) over the course of a few days.[1] The warming is preceded by a slowing then reversal of the westerly winds in the stratospheric polar vortex, commonly measured at 60  ° latitude at the 10 hPa level[2]. SSWs occur about six times per decade in the northern hemisphere (NH),[3] and about once every 20-30 years in the southern hemisphere (SH).[4][5] In the SH, SSW accompanied by a reversal of the vortex westerly (which is soon after followed by a vortex recovery) was observed once during the period 1979–2024; this was in September 2002[6]. Stratospheric warming in September 2019 was comparable to or even greater than that of 2002, but the wind reversal did not occur.[7][8][9]

History

[edit]

The first continued measurements of the stratosphere were taken by Richard Scherhag in 1951 using radiosondes to take reliable temperature readings in the upper stratosphere (~40 km) and he became the first to observe stratospheric warming on 27 January 1952. After his discovery, he assembled a team of meteorologists at the Free University of Berlin specifically to study the stratosphere, and this group continued to map the NH stratospheric temperature and geopotential height for many years using radiosondes and rocketsondes.

In 1979 when the satellite era began[dubious – discuss], meteorological measurements became far more frequent. Although satellites were primarily used for the troposphere, they also recorded data for the stratosphere. Today both satellites and stratospheric radiosondes are used to take measurements of the stratosphere.

Classification and description

[edit]

SSW is closely associated with polar vortex breakdown. Meteorologists typically classify vortex breakdown into three categories: major, minor, and final. No unambiguous standard definition of these has so far been adopted.[3] However, differences in the methodology to detect SSWs are not relevant as long as circulation in the polar stratosphere reverses.[10] "Major SSWs occur when the winter polar stratospheric westerlies reverse to easterlies. In minor warmings, the polar temperature gradient reverses but the circulation does not, and in final warmings, the vortex breaks down and remains easterly until the following boreal autumn".[3] However, this classification is based on the NH SSWs, as no major SSW by this definition has been observed in the SH in winter[11].

Sometimes a fourth category, the Canadian warming, is included because of its unique and distinguishing structure and evolution.

"There are two main types of SSW: displacement events in which the stratospheric polar vortex is displaced from the pole and split events in which the vortex splits into two or more vortices. Some SSWs are a combination of both types".[3]

Major

[edit]

These occur when the westerly winds at 60°N and 10 hPa reverse, i.e. become easterly. A complete disruption of the polar vortex is observed and the vortex will either be split into daughter vortices, or displaced from its normal location over the pole.

According to the World Meteorological Organization's Commission for Atmospheric Sciences:[12]: 19  "a stratospheric warming can be said to be major if at 10 mb or below the latitudinal mean temperature increases poleward from 60 degree latitude and an associated circulation reversal is observed (that is, the prevailing mean westerly winds poleward of 60° latitude are succeeded by mean easterlies in the same area)."

Minor

[edit]

Minor warmings are similar to major warmings; however, they are less dramatic: the westerly winds are slowed but do not reverse. Therefore, a breakdown of the vortex is never observed. All the SH SSWs observed since 1979 were minor warmings except for that in September 2002.Cite error: A <ref> tag is missing the closing </ref> (see the help page).[13][14] In this sense, SH SSWs represent faster-than-normal seasonal march of the westerly polar vortex.[13][15][16]

Canadian

[edit]

Canadian warmings occur in early winter in the stratosphere of the NH, typically from mid-November to early December. They have no counterpart in the SH.

Dynamics

[edit]

In a usual NH winter, several minor warming events occur, with a major event occurring roughly every two years. One reason for major stratospheric warmings in the NH is that orography and land-sea temperature contrasts are responsible for the generation of long (wavenumber 1 or 2)[clarification needed] Rossby waves in the troposphere. These planetary-scale waves travel upward to the stratosphere and dissipate there, decelerating the westerly winds and warming the Arctic.[17] This is the reason that major warmings are usually only observed in the NH, with an exception observed in September 2002.[18][19][20] As the SH is largely an ocean hemisphere[21], the planetary-scale wave activity is much weaker, and the SH vortex westerly is much stronger in winter, which partly explains why major SSW has not been observed in the SH winter at least in the instrumental observation era.

At an initial time a blocking-type circulation pattern establishes in the troposphere. This blocking pattern causes[clarification needed] Rossby waves with zonal wavenumber 1 and/or 2[22] to grow to unusually large amplitudes. The growing wave propagates into the stratosphere and decelerates the westerly mean zonal winds.[clarification needed] Thus the polar night jet weakens and simultaneously becomes distorted by the growing planetary waves. Because the wave amplitude increases with decreasing density, this easterly acceleration process is not effective at fairly high levels.[why?] If the waves are sufficiently strong, the mean zonal flow may decelerate sufficiently so that the winter westerlies turn easterly. At this point planetary waves may no longer penetrate into the stratosphere [23][clarification needed]). Hence, further upward transfer of energy is completely blocked and a very rapid easterly acceleration and the polar warming occur at this critical level, which must then move downward until eventually the warming and zonal wind reversal affect the entire polar stratosphere. This wave-mean flow interaction explains the stratosphere-troposphere downward coupling during the SH SSW events as well.[8][24] The upward propagation of planetary waves and their interaction with the stratospheric mean flow is traditionally diagnosed via so-called Eliassen-Palm fluxes.[25][26]

There is a link between sudden stratospheric warmings and the quasi-biennial oscillation (QBO): if the QBO is in its easterly phase, the atmospheric waveguide is modified in such a way that upward-propagating Rossby waves are focused on the polar vortex, intensifying their interaction with the mean flow. Thus, there exists a statistically significant imbalance between the frequency of sudden stratospheric warmings if these events are grouped according to the QBO phase (easterly or westerly). However, the QBO-polar vortex relationship is less statistically significant in the SH.[9][13]

Weather and climate effects

[edit]

Although sudden stratospheric warmings are mainly forced by planetary-scale waves which propagate up from the lower atmosphere, there is also a subsequent return effect of sudden stratospheric warmings on surface weather and climate. Following a sudden stratospheric warming, the high altitude westerly winds reverse and are replaced by easterlies. The easterly winds progress down through the atmosphere, often leading to a weakening of the tropospheric westerly winds, resulting in dramatic reductions in temperature in Northern Europe.[27] This process can take a few days to a few weeks to occur.[1]

Similar downward processes are found in the SH in the austral late spring to early summer seasons. SH SSWs in austral spring tend to cause the Antarctic ozone concentration to be higher than normal from spring to early summer.[14][28][29][30], and they together cause the tropospheric jet to shift equatorward[31], which is expressed as a negative phase of the Southern Annular Mode (SAM)[32][[1]] in the SH extratropical geopotential height and surface pressure fields in the subsequent late spring to early summer seasons.[14][16][33] SSWs in austral spring have been found to result in warmer and drier conditions over eastern Australia during late spring-early summer[34][35], increasing the risk of forest/bush fires[35], but cooler and wetter conditions over Patagonia.[14] Also, austral spring to late spring SSWs influence the Antarctic sea-ice extent in the subsequent early summer season.[14][36]

Table of major mid-winter Sudden Stratospheric Warming Events in Reanalyses[clarification needed] Products[37]

[edit]

[What do the four asterisks mean?]

Event Name NCEP-NCAR
[clarification needed] 		ERA40
[clarification needed] 		ERA-Interim JRA-55
[clarification needed] 		MERRA2
[clarification needed] 		ENSO
[clarification needed] 		QBO 50mb
JAN 1958 30-Jan-58 31-Jan-58 30-Jan-58 El Niño West
NOV 1958 30-Nov-58 **** **** El Niño East
JAN 1960 16-Jan-60 17-Jan-60 17-Jan-60 Neutral West
JAN 1963 **** 28-Jan-63 30-Jan-63 Neutral East
MAR 1965 23-Mar-65 **** **** La Niña West
DEC 1965 8-Dec-65 16-Dec-65 18-Dec-65 El Niño East
FEB 1966 24-Feb-66 23-Feb-66 23-Feb-66 El Niño East
JAN 1968 **** 7-Jan-68 7-Jan-68 La Niña West
NOV 1968 27-Nov-68 28-Nov-68 29-Nov-68 El Niño East
MAR 1969 13-Mar-69 13-Mar-69 **** El Niño East
JAN 1970 2-Jan-70 2-Jan-70 2-Jan-70 El Niño West
JAN 1971 17-Jan-71 18-Jan-71 18-Jan-71 La Niña East
MAR 1971 20-Mar-71 20-Mar-71 20-Jan-71 La Niña East
JAN 1973 2-Feb-73 31-Jan-73 31-Jan-73 El Niño East
JAN 1977 **** 9-Jan-77 9-Jan-77 El Niño East
FEB 1979 22-Feb-79 22-Feb-79 22-Feb-79 22-Feb-79 Neutral West
FEB 1980 29-Feb-80 29-Feb-80 29-Feb-80 29-Feb-80 29-Feb-80 El Niño East
FEB 1981 **** **** **** 6-Feb-81 **** Neutral West
MAR 1981 **** 4-Mar-81 4-Mar-81 4-Mar-81 **** Neutral West
DEC 1981 4-Dec-81 4-Dec-81 4-Dec-81 4-Dec-81 4-Dec-81 Neutral East
FEB 1984 24-Feb-84 24-Feb-84 24-Feb-84 24-Feb-84 24-Feb-84 La Niña West
JAN 1985 2-Jan-85 1-Jan-85 1-Jan-85 1-Jan-85 1-Jan-85 La Niña East
JAN 1987 23-Jan-87 23-Jan-87 23-Jan-87 23-Jan-87 23-Jan-87 El Niño West
DEC 1987 8-Dec-87 8-Dec-87 8-Dec-87 8-Dec-87 8-Dec-87 El Niño West
MAR 1988 14-Mar-88 14-Mar-88 14-Mar-88 14-Mar-88 14-Mar-88 El Niño West
FEB 1989 22-Feb-89 21-Feb-89 21-Feb-89 21-Feb-89 21-Feb-89 La Niña West
DEC 1998 15-Dec-98 15-Dec-98 15-Dec-98 15-Dec-98 15-Dec-98 La Niña East
FEB 1999 25-Feb-99 26-Feb-99 26-Feb-99 26-Feb-99 26-Feb-99 La Niña East
MAR 2000 20-Mar-00 20-Mar-00 20-Mar-00 20-Mar-00 20-Mar-00 La Niña West
FEB 2001 11-Feb-01 11-Feb-01 11-Feb-01 11-Feb-01 11-Feb-01 La Niña West
DEC 2001 2-Jan-02 31-Dec-01 30-Dec-01 31-Dec-01 30-Dec-01 Neutral East
FEB 2002 **** 18-Feb-02 **** **** 17-Feb-02 Neutral East
JAN 2003 18-Jan-03 18-Jan-03 18-Jan-03 18-Jan-03 El Niño West
JAN 2004 7-Jan-04 5-Jan-04 5-Jan-04 5-Jan-04 Neutral East
JAN 2006 21-Jan-06 21-Jan-06 21-Jan-06 21-Jan-06 La Niña East
FEB 2007 24-Feb-07 24-Feb-07 24-Feb-07 24-Feb-07 El Niño West
FEB 2008 22-Feb-08 22-Feb-08 22-Feb-08 22-Feb-08 La Niña East
JAN 2009 24-Jan-09 24-Jan-09 24-Jan-09 24-Jan-09 La Niña West
FEB 2010 9-Feb-10 9-Feb-10 9-Feb-10 9-Feb-10 El Niño West
MAR 2010 24-Mar-10 24-Mar-10 24-Mar-10 24-Mar-10 El Niño West
JAN 2013 7-Jan-13 6-Jan-13 7-Jan-13 6-Jan-13 Neutral East
FEB 2018 12-Feb-18 12-Feb-18 12-Feb-18 12-Feb-18 La Niña West
JAN 2019 2-Jan-19 2-Jan-19 2-Jan-19 2-Jan-19 El Niño East
JAN 2021[38][39] La Niña[40] West[41]

See also

[edit]

References

[edit]
  1. ^ a b "Sudden Stratospheric Warming". Met Office.
  2. ^ Butler, Amy H.; Gerber, Edwin P. (15 March 2018). "Optimizing the Definition of a Sudden Stratospheric Warming". Journal of Climate. 31 (6): 2337–2344. Bibcode:2018JCli...31.2337B. doi:10.1175/JCLI-D-17-0648.1.
  3. ^ a b c d Butler, Amy H.; Sjoberg, Jeremiah P.; Seidel, Dian J.; Rosenlof, Karen H. (9 February 2017). "A sudden stratospheric warming compendium". Earth System Science Data. 9 (1): 63–76. Bibcode:2017ESSD....9...63B. doi:10.5194/essd-9-63-2017.
  4. ^ Wang, L; Hardiman, S C; Bett, P E; Comer, R E; Kent, C; Scaife, A A (2020-09-24). "What chance of a sudden stratospheric warming in the southern hemisphere?". Environmental Research Letters. 15 (10). IOP Publishing: 104038. Bibcode:2020ERL....15j4038W. doi:10.1088/1748-9326/aba8c1. ISSN 1748-9326.
  5. ^ Jucker, Martin; Reichler, Thomas; Waugh, Darryn (2021). "How frequent are Antarctic sudden stratospheric warmings in present and future climate?". Geophysical Research Letters. 48 (11). Bibcode:2021GeoRL..4893215J. doi:10.1029/2021GL093215. hdl:1959.4/unsworks_79028. S2CID 236260013.
  6. ^ Newman, Paul A.; Nash, Eric R. (1 March 2005). "The Unusual Southern Hemisphere Stratosphere Winter of 2002". Journal of the Atmospheric Sciences. 62 (3): 614–628. Bibcode:2005JAtS...62..614N. doi:10.1175/JAS-3323.1.
  7. ^ Rao, Jian; Garfinkel, Chaim I.; White, Ian P.; Schwartz, Chen (27 July 2020). "The Southern Hemisphere Minor Sudden Stratospheric Warming in September 2019 and its Predictions in S2S Models". Journal of Geophysical Research: Atmospheres. 125 (14). Bibcode:2020JGRD..12532723R. doi:10.1029/2020JD032723.
  8. ^ a b Lim, Eun-Pa; Hendon, Harry H.; Butler, Amy H.; Thompson, David W. J.; Lawrence, Zachary D.; Scaife, Adam A.; Shepherd, Theodore G.; Polichtchouk, Inna; Nakamura, Hisashi; Kobayashi, Chiaki; Comer, Ruth; Coy, Lawrence; Dowdy, Andrew; Garreaud, Rene D.; Newman, Paul A.; Wang, Guomin (June 2021). "The 2019 Southern Hemisphere Stratospheric Polar Vortex Weakening and Its Impacts". Bulletin of the American Meteorological Society. 102 (6): E1150–E1171. Bibcode:2021BAMS..102E1150L. doi:10.1175/BAMS-D-20-0112.1.
  9. ^ a b Shen, Xiaocen; Wang, Lin; Osprey, Scott (2020). "The Southern Hemisphere sudden stratospheric warming of September 2019". Science Bulletin. 65 (21): 1800–1802. Bibcode:2020SciBu..65.1800S. doi:10.1016/j.scib.2020.06.028. PMID 36659119.
  10. ^ Palmeiro, Froila M; Barriopedro, David; Garcia-Herrera, Ricardo; Calvo, Natalia (2015). "Comparing Sudden Stratospheric Warming Definitions in Reanalysis Data" (PDF). Journal of Climate. 28 (17): 6823–6840. Bibcode:2015JCli...28.6823P. doi:10.1175/JCLI-D-15-0004.1. hdl:10261/122618. S2CID 53970984.
  11. ^ NASA. NASA Ozone Watch. NASA Goddard Space Flight Center https://ozonewatch.gsfc.nasa.gov/meteorology/figures/merra2/wind/u60s_10_2024_merra2.pdf. {{cite web}}: Missing or empty |title= (help)
  12. ^ McInturff, Raymond M., ed. (1978). Stratospheric warmings: Synoptic, dynamic and general-circulation aspects (PDF) (Report). NASA Scientific and Technical Information Office. Retrieved 3 July 2024.
  13. ^ a b c Hio, Yasuko; Yoden, Shigeo (1 March 2005). "Interannual Variations of the Seasonal March in the Southern Hemisphere Stratosphere for 1979–2002 and Characterization of the Unprecedented Year 2002". Journal of the Atmospheric Sciences. 62 (3): 567–580. doi:10.1175/JAS-3333.1.
  14. ^ a b c d e Lim, E.‐P.; Hendon, H. H.; Thompson, D. W. J. (16 November 2018). "Seasonal Evolution of Stratosphere‐Troposphere Coupling in the Southern Hemisphere and Implications for the Predictability of Surface Climate". Journal of Geophysical Research: Atmospheres. 123 (21). doi:10.1029/2018JD029321.
  15. ^ Shiotani, Masato; Shimoda, Naoki; Hirota, Isamu (April 1993). "Interannual variability of the stratospheric circulation in the southern hemisphere". Quarterly Journal of the Royal Meteorological Society. 119 (511): 531–546. doi:10.1002/qj.49711951110.
  16. ^ a b Byrne, Nicholas J.; Shepherd, Theodore G. (May 2018). "Seasonal Persistence of Circulation Anomalies in the Southern Hemisphere Stratosphere and Its Implications for the Troposphere". Journal of Climate. 31 (9): 3467–3483. doi:10.1175/JCLI-D-17-0557.1.
  17. ^ Eliassen, A; Palm, T (1960). "On the transfer of energy in stationary mountain waves". Geofysiske Publikasjoner. 22: 1023.
  18. ^ Varotsos, C. (2002). "The southern hemisphere ozone hole split in 2002". Environmental Science and Pollution Research. 9 (6): 375–376. Bibcode:2002ESPR....9..375V. doi:10.1007/BF02987584. PMID 12515343. S2CID 45351011.
  19. ^ Manney, Gloria L.; Sabutis, Joseph L.; Allen, Douglas R.; Lahoz, William A.; Scaife, Adam A.; Randall, Cora E.; Pawson, Steven; Naujokat, Barbara; Swinbank, Richard (2005). "Simulations of Dynamics and Transport during the September 2002 Antarctic Major Warming". Journal of the Atmospheric Sciences. 62 (3): 690. Bibcode:2005JAtS...62..690M. doi:10.1175/JAS-3313.1. S2CID 119492652.
  20. ^ Lewis, Dyani (2019). "Rare warming over Antarctica reveals power of stratospheric models". Nature. 574 (7777): 160–161. Bibcode:2019Natur.574..160L. doi:10.1038/d41586-019-02985-8. PMID 31595070.
  21. ^ CSIRO. "New research centre focuses on the 'ocean hemisphere'". www.csiro.au.
  22. ^ Ripesi, Patrizio; Ciciulla, Fabrizio; Maimone, Filippo; Pelino, Vinizio (2012). "The February 2010 Arctic Oscillation Index and its stratospheric connection". Quarterly Journal of the Royal Meteorological Society. 138 (669): 1961–1969. Bibcode:2012QJRMS.138.1961R. doi:10.1002/qj.1935. S2CID 122729063.
  23. ^ Charney, J. G.; Drazin, P. G. (1961). "Propagation of planetary-scale disturbances from the lower into the upper atmosphere". Journal of Geophysical Research. 66 (1): 83–109. Bibcode:1961JGR....66...83C. doi:10.1029/JZ066i001p00083. S2CID 129826760.
  24. ^ Hartmann, Dennis L.; Mechoso, Carlos R.; Yamazaki, Koji (February 1984). "Observations of Wave-Mean Flow Interaction in the Southern Hemisphere". Journal of the Atmospheric Sciences. 41 (3): 351–362. doi:10.1175/1520-0469(1984)041<0351:OOWMFI>2.0.CO;2.
  25. ^ Andrews, D.G.; McIntyre, M.E. (1976). "Planetary waves in horizontal and vertical shear: the generalized Eliassen-Palm relation and the mean zonal acceleration". Journal of the Atmospheric Sciences. 33 (11): 2031–2048. Bibcode:1976JAtS...33.2031A. doi:10.1175/1520-0469(1976)033<2031:PWIHAV>2.0.CO;2.
  26. ^ Jucker, Martin (2021). "Scaling of Eliassen-Palm flux vectors". Atmospheric Science Letters. 22 (4). Bibcode:2021AtScL..22E1020J. doi:10.1002/asl.1020.
  27. ^ King, A.D.; Butler, A.H.; Jucker, M.; Earl, N.O.; Rudeva, I. (2019). "Observed Relationships Between Sudden Stratospheric Warmings and European Climate Extremes". Journal of Geophysical Research: Atmospheres. 124 (24): 13943–13961. Bibcode:2019JGRD..12413943K. doi:10.1029/2019JD030480. hdl:11343/286789.
  28. ^ Stolarski, Richard S.; McPeters, Richard D.; Newman, Paul A. (1 March 2005). "The Ozone Hole of 2002 as Measured by TOMS". Journal of the Atmospheric Sciences. 62 (3): 716–720. doi:10.1175/JAS-3338.1.
  29. ^ Seviour, William J. M.; Hardiman, Steven C.; Gray, Lesley J.; Butchart, Neal; MacLachlan, Craig; Scaife, Adam A. (1 October 2014). "Skillful Seasonal Prediction of the Southern Annular Mode and Antarctic Ozone". Journal of Climate. 27 (19): 7462–7474. doi:10.1175/JCLI-D-14-00264.1.
  30. ^ Jucker, M.; Goyal, R. (28 February 2022). "Ozone‐Forced Southern Annular Mode During Antarctic Stratospheric Warming Events". Geophysical Research Letters. 49 (4). doi:10.1029/2021GL095270.
  31. ^ Hendon, H. H.; Lim, E.‐P.; Abhik, S. (27 August 2020). "Impact of Interannual Ozone Variations on the Downward Coupling of the 2002 Southern Hemisphere Stratospheric Warming". Journal of Geophysical Research: Atmospheres. 125 (16). doi:10.1029/2020JD032952.
  32. ^ Thompson, David W. J.; Wallace, John M. (March 2000). "Annular Modes in the Extratropical Circulation. Part I: Month-to-Month Variability*". Journal of Climate. 13 (5): 1000–1016. doi:10.1175/1520-0442(2000)013<1000:AMITEC>2.0.CO;2.
  33. ^ Thompson, David W. J.; Baldwin, Mark P.; Solomon, Susan (1 March 2005). "Stratosphere–Troposphere Coupling in the Southern Hemisphere". Journal of the Atmospheric Sciences. 62 (3): 708–715. doi:10.1175/JAS-3321.1.
  34. ^ Bandoro, Justin; Solomon, Susan; Donohoe, Aaron; Thompson, David W. J.; Santer, Benjamin D. (15 August 2014). "Influences of the Antarctic Ozone Hole on Southern Hemispheric Summer Climate Change". Journal of Climate. 27 (16): 6245–6264. doi:10.1175/JCLI-D-13-00698.1.
  35. ^ a b Lim, Eun-Pa; Hendon, Harry H.; Boschat, Ghyslaine; Hudson, Debra; Thompson, David W. J.; Dowdy, Andrew J.; Arblaster, Julie M. (November 2019). "Australian hot and dry extremes induced by weakenings of the stratospheric polar vortex". Nature Geoscience. 12 (11): 896–901. doi:10.1038/s41561-019-0456-x.
  36. ^ Wang, Guomin; Hendon, Harry H.; Arblaster, Julie M.; Lim, Eun-Pa; Abhik, S.; van Rensch, Peter (2 January 2019). "Compounding tropical and stratospheric forcing of the record low Antarctic sea-ice in 2016". Nature Communications. 10 (1). doi:10.1038/s41467-018-07689-7.
  37. ^ Laboratory (CSL), NOAA Chemical Sciences. "NOAA CSL: Chemistry & Climate Processes: SSWC". csl.noaa.gov. Retrieved 2022-11-23.
  38. ^ Lu, Qian; Rao, Jian; Liang, Zhuoqi; Guo, Dong; Luo, Jingjia; Liu, Siming; Wang, Chun; Wang, Tian (2021-07-28). "The sudden stratospheric warming in January 2021". Environmental Research Letters. 16 (8): 084029. Bibcode:2021ERL....16h4029L. doi:10.1088/1748-9326/ac12f4. ISSN 1748-9326.
  39. ^ "On the sudden stratospheric warming and polar vortex of early 2021 | NOAA Climate.gov". www.climate.gov. Retrieved 2022-11-23.
  40. ^ Center, NOAA's Climate Prediction. "NOAA's Climate Prediction Center". origin.cpc.ncep.noaa.gov. Retrieved 2022-11-23.
  41. ^ "Climate Prediction Center - Monitoring & Data: Current Monthly Atmospheric and Sea Surface Temperatures Index Values". www.cpc.ncep.noaa.gov. Retrieved 2022-11-23.

Further reading

[edit]
[edit]
Retrieved from "https://en.wikipedia.org/w/index.php?title=Sudden_stratospheric_warming&oldid=1250452108"