Abstract
For the first time in several years, the El Nino-Southern Oscillation did not dominate regional climate conditions around the globe. A weak La Niña dissipated to ENSO-neutral conditions by spring, and while El Nino appeared to be emerging during summer, this phase never fully developed as sea surface temperatures in the eastern equatorial Pacific uncharacteristically returned to neutral conditions. Nevertheless, other large-scale climate patterns and extreme weather events impacted various regions during the year. A negative phase of the Arctic Oscillation from mid-January to early February contributed to frigid conditions in parts of northern Africa, eastern Europe, and western Asia. A lack of rain during the 2012 wet season led to the worst drought in at least the past three decades for northeastern Brazil. Central North America also experienced one of its most severe droughts on record. The Caribbean observed a very wet dry season and it was the Sahel's wettest rainy season in 50 years. Overall, the 2012 average temperature across global land and ocean surfaces ranked among the 10 warmest years on record. The global land surface temperature alone was also among the 10 warmest on record. In the upper atmosphere, the average stratospheric temperature was record or near-record cold, depending on the dataset. After a 30-year warming trend from 1970 to 1999 for global sea surface temperatures, the period 2000-12 had little further trend. This may be linked to the prevalence of La Niña-like conditions during the 21st century. Heat content in the upper 700 m of the ocean remained near record high levels in 2012. Net increases from 2011 to 2012 were observed at 700-m to 2000-m depth and even in the abyssal ocean below. Following sharp decreases in global sea level in the first half of 2011 that were linked to the effects of La Niña, sea levels rebounded to reach records highs in 2012. The increased hydrological cycle seen in recent years continued, with more evaporation in drier locations and more precipitation in rainy areas. In a pattern that has held since 2004, salty areas of the ocean surfaces and subsurfaces were anomalously salty on average, while fresher areas were anomalously fresh. Global tropical cyclone activity during 2012 was near average, with a total of 84 storms compared with the 1981-2010 average of 89. Similar to 2010 and 2011, the North Atlantic was the only hurricane basin that experienced above-normal activity. In this basin, Sandy brought devastation to Cuba and parts of the eastern North American seaboard. All other basins experienced either near- or below-normal tropical cyclone activity. Only three tropical cyclones reached Category 5 intensity-all in the Western North Pacific basin. Of these, Super Typhoon Bopha became the only storm in the historical record to produce winds greater than 130 kt south of 7°N. It was also the costliest storm to affect the Philippines and killed more than 1000 residents. Minimum Arctic sea ice extent in September and Northern Hemisphere snow cover extent in June both reached new record lows. June snow cover extent is now declining at a faster rate (-17.6% per decade) than September sea ice extent (-13.0% per decade). Permafrost temperatures reached record high values in northernmost Alaska. A new melt extent record occurred on 11-12 July on the Greenland ice sheet; 97% of the ice sheet showed some form of melt, four times greater than the average melt for this time of year. The climate in Antarctica was relatively stable overall. The largest maximum sea ice extent since records begain in 1978 was observed in September 2012. In the stratosphere, warm air led to the second smallest ozone hole in the past two decades. Even so, the springtime ozone layer above Antarctica likely will not return to its early 1980s state until about 2060. Following a slight decline associated with the global financial crisis, global CO2 emissions from fossil fuel combustion and cement production reached a record 9.5 ± 0.5 Pg C in 2011 and a new record of 9.7 ± 0.5 Pg C is estimated for 2012. Atmospheric CO2 concentrations increased by 2.1 ppm in 2012, to 392.6 ppm. In spring 2012, for the first time, the atmospheric CO2 concentration exceeded 400 ppm at 7 of the 13 Arctic observation sites. Globally, other greenhouse gases including methane and nitrous oxide also continued to rise in concentration and the combined effect now represents a 32% increase in radiative forcing over a 1990 baseline. Concentrations of most ozone depleting substances continued to fall.
| Original language | English |
|---|---|
| Journal | Bulletin of the American Meteorological Society |
| Volume | 94 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - Aug 2013 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Atmospheric Science
Cite this
State of the climate in 2012. / Achberger, Christine; Ackerman, Stephen A.; Albanil, Adelina; Alexander, P.; Alfaro, Eric J.; Allan, Rob; Alves, Lincoln M.; Amador, Jorge A.; Ambenje, Peter; Andrianjafinirina, Solonomenjanahary; Antonov, John; Aravequia, Jose A.; Arendt, A.; Arévalo, Juan; Arndt, Derek S.; Ashik, I.; Atheru, Zachary; Banzon, Viva; Baringer, Molly O.; Barreira, Sandra; Barriopedro, David E.; Beard, Grant; Becker, Andreas; Behrenfeld, Michael J.; Bell, Gerald D.; Benedetti, Angela; Bernhard, Germar; Berrisford, Paul; Berry, David I.; Bhatt, U.; Bidegain, Mario; Bindoff, Nathan; Bissolli, Peter; Blake, Eric S.; Blunden, Jessica; Booneeady, Raj; Bosilovich, Michael; Box, J. E.; Boyer, Tim; Braathen, Geir O.; Bromwich, David H.; Brown, R.; Brown, L.; Bruhwiler, Lori; Bulygina, Olga N.; Burgess, D.; Burrows, John; Calderón, Blanca; Camargo, Suzana J.; Campbell, Jayaka; Cao, Y.; Cappelen, J.; Carrasco, Gualberto; Chambers, Don P.; Chang'A, L.; Chappell, Petra; Chehade, Wissam; Cheliah, Muthuvel; Christiansen, Hanne H.; Christy, John R.; Ciais, Phillipe; Coelho, Caio A.S.; Cogley, J. G.; Colwell, Steve; Cross, J. N.; Crouch, Jake; Cunningham, Stuart A.; Dacic, Milan; De Jeu, Richard A.M.; Dekaa, Francis S.; Demircan, Mesut; Derksen, C.; Diamond, Howard J.; Dlugokencky, Ed J.; Dohan, Kathleen; Dolman, A. Johannes; Domingues, Catia M.; Dong, Shenfu; Dorigo, Wouter A.; Drozdov, D. S.; Duguay, Claude R.; Dunn, Robert J.H.; Dúran-Quesada, Ana M.; Dutton, Geoff S.; Ehmann, Christian; Elkins, James W.; Euscátegui, Christian; Famiglietti, James S.; Fang, Fan; Fauchereau, Nicolas; Feely, Richard A.; Fekete, Balázs M.; Fenimore, Chris; Fioletov, Vitali E.; Fogarty, Chris T.; Fogt, Ryan L.; Folland, Chris K.; Foster, Michael J.; Frajka-Williams, Eleanor; Franz, Bryan A.; Frith, Stacey H.; Frolov, I.; Ganter, Catherine; Garzoli, Silvia; Geai, M. L.; Gerland, S.; Gitau, Wilson; Gleason, Karin L.; Gobron, Nadine; Goldenberg, Stanley B.; Goni, Gustavo; Good, Simon A.; Gottschalck, Jonathan; Gregg, Margarita C.; Griffiths, Georgina; Grooß, Jens Uwe; Guard, Charles Chip; Gupta, Shashi K.; Hall, Bradley D.; Halpert, Michael S.; Harada, Yayoi; Hauri, C.; Heidinger, Andrew K.; Heikkilä, Anu; Heim, Richard R.; Heimbach, Patrick; Hidalgo, Hugo G.; Hilburn, Kyle; Ho, Shu Peng; Hobbs, Will R.; Holgate, Simon; Hovsepyan, Anahit; Hu, Zeng Zhen; Hughes, P.; Hurst, Dale F.; Ingvaldsen, R.; Inness, Antje; Jaimes, Ena; Jakobsson, Martin; James, Adamu I.; Jeffries, Martin O.; Johns, William E.; Johnsen, Bjorn; Johnson, Gregory C.; Johnson, Bryan; Jones, Luke T.; Jumaux, Guillaume; Kabidi, Khadija; Kaiser, Johannes W.; Kamga, Andre; Kang, Kyun Kuk; Kanzow, Torsten O.; Kao, Hsun Ying; Keller, Linda M.; Kennedy, John J.; Key, J.; Khatiwala, Samar; Kheyrollah Pour, H.; Kholodov, A. L.; Khoshkam, Mahbobeh; Kijazi, Agnes; Kikuchi, T.; Kim, B. M.; Kim, S. J.; Kimberlain, Todd B.; Knaff, John A.; Korshunova, Natalia N.; Koskela, T.; Kousky, Vernon E.; Kramarova, Natalya; Kratz, David P.; Krishfield, R.; Kruger, Andries; Kruk, Michael C.; Kumar, Arun; Lagerloef, Gary S.E.; Lakkala, K.; Lander, Mark A.; Landsea, Chris W.; Lankhorst, Matthias; Laurila, T.; Lazzara, Matthew A.; Lee, Craig; Leuliette, Eric; Levitus, Sydney; L'Heureux, Michelle; Lieser, Jan; Lin, I. I.; Liu, Y.; Liu, Y.; Liu, Hongxing; Liu, Yanju; Lobato-Sánchez, Rene; Locarnini, Ricardo; Loeb, Norman G.; Loeng, H.; Long, Craig S.; Lorrey, Andrew M.; Luhunga, P.; Lumpkin, Rick; Luo, Jing Jia; Lyman, John M.; Macdonald, Alison M.; Maddux, Brent C.; Malekela, C.; Manney, Gloria; Marchenko, S. S.; Marengo, Jose A.; Marotzke, Jochem; Marra, John J.; Martínez-Güingla, Rodney; Massom, Robert A.; Mathis, Jeremy T.; McBride, Charlotte; McCarthy, Gerard; McVicar, Tim R.; Mears, Carl; Meier, W.; Meinen, Christopher S.; Menéndez, Melisa; Merrifield, Mark A.; Mitchard, Edward; Mitchum, Gary T.; Montzka, Stephen A.; Morcrette, Jean Jacques; Mote, Thomas; Mühle, Jens; Mühr, Bernhard; Mullan, A. Brett; Müller, Rolf; Nash, Eric R.; Nerem, R. Steven; Newlin, Michele L.; Newman, Paul A.; Ng'Ongolo, H.; Nieto, Juan José; Nishino, S.; Nitsche, Helga; Noetzli, Jeannette; Oberman, N. G.; Obregón, Andre; Ogallo, Laban A.; Oludhe, Christopher S.; Omar, Mohamed I.; Overland, James; Oyunjargal, Lamjav; Parinussa, Robert M.; Park, Geun Ha; Park, E. Hyung; Parker, David; Pasch, Richard J.; Pascual-Ramírez, Reynaldo; Pelto, Mauri S.; Penalba, Olga; Peng, L.; Perovich, Don K.; Pezza, Alexandre B.; Phillips, David; Pickart, R.; Pinty, Bernard; Pitts, Michael C.; Purkey, Sarah G.; Quegan, Shaun; Quintana, Juan; Rabe, B.; Rahimzadeh, Fatemeh; Raholijao, Nirivololona; Raiva, I.; Rajeevan, Madhavan; Ramiandrisoa, Voahanginirina; Ramos, Alexandre; Ranivoarissoa, Sahondra; Rayner, Nick A.; Rayner, Darren; Razuveav, Vyacheslav N.; Reagan, James; Reid, Phillip; Renwick, James; Revedekar, Jayashree; Richter-Menge, Jacqueline; Rivera, Ingrid L.; Robinson, David A.; Rodell, Matthew; Romanovsky, Vladimir E.; Ronchail, Josyane; Rosenlof, Karen H.; Sabine, Christopher L.; Salvador, Mozar A.; Sánchez-Lugo, Ahira; Santee, Michelle L.; Sasgen, I.; Sawaengphokhai, P.; Sayouri, Amal; Scambos, Ted A.; Schauer, U.; Schemm, Jae; Schlosser, P.; Schmid, Claudia; Schreck, Carl; Semiletov, Igor; Send, Uwe; Sensoy, Serhat; Setzer, Alberto; Severinghaus, Jeffrey; Shakhova, Natalia; Sharp, M.; Shiklomanov, Nicolai I.; Siegel, David A.; Silva, Viviane B.S.; Silva, Frabricio D.S.; Sima, Fatou; Simeonov, Petio; Simmonds, I.; Simmons, Adrian; Skansi, Maria; Smeed, David A.; Smethie, W. M.; Smith, Adam B.; Smith, Cathy; Smith, Sharon L.; Smith, Thomas M.; Sokolov, V.; Srivastava, A. K.; Stackhouse, Paul W.; Stammerjohn, Sharon; Steele, M.; Steffen, Konrad; Steinbrecht, Wolfgang; Stephenson, Tannecia; Su, J.; Svendby, T.; Sweet, William; Takahashi, Taro; Tanabe, Raymond M.; Taylor, Michael A.; Tedesco, Marco; Teng, William L.; Thépaut, Jean Noel; Thiaw, Wassila M.; Thoman, R.; Thompson, Philip; Thorne, Peter W.; Timmermans, M. L.; Tobin, Skie; Toole, J.; Trewin, Blair C.; Trigo, Ricardo M.; Trotman, Adrian; Tschudi, M.; Van De Wal, Roderik S.W.; Van Der Werf, Guido R.; Vautard, Robert; Vazquez, J. L.; Vieira, Gonçalo; Vincent, Lucie; Vose, Russ S.; Wagner, Wolfgang W.; Wahr, John; Walsh, J.; Wang, Junhong; Wang, Chunzai; Wang, M.; Wang, Sheng Hung; Wang, Lei; Wanninkhof, Rik; Weaver, Scott; Weber, Mark; Werdell, P. Jeremy; Whitewood, Robert; Wijffels, Susan; Wilber, Anne C.; Wild, J. D.; Willett, Kate M.; Williams, W.; Willis, Joshua K.; Wolken, G.; Wong, Takmeng; Woodgate, R.; Worthy, D.; Wouters, B.; Wovrosh, Alex J.; Xue, Yan; Yamada, Ryuji; Yin, Zungang; Yu, Lisan; Zhang, Liangying; Zhang, Peiqun; Zhao, Lin; Zhao, J.; Zhong, W.; Ziemke, Jerry; Zimmermann, S.
In: Bulletin of the American Meteorological Society, Vol. 94, No. 8, 08.2013.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - State of the climate in 2012
AU - Achberger, Christine
AU - Ackerman, Stephen A.
AU - Albanil, Adelina
AU - Alexander, P.
AU - Alfaro, Eric J.
AU - Allan, Rob
AU - Alves, Lincoln M.
AU - Amador, Jorge A.
AU - Ambenje, Peter
AU - Andrianjafinirina, Solonomenjanahary
AU - Antonov, John
AU - Aravequia, Jose A.
AU - Arendt, A.
AU - Arévalo, Juan
AU - Arndt, Derek S.
AU - Ashik, I.
AU - Atheru, Zachary
AU - Banzon, Viva
AU - Baringer, Molly O.
AU - Barreira, Sandra
AU - Barriopedro, David E.
AU - Beard, Grant
AU - Becker, Andreas
AU - Behrenfeld, Michael J.
AU - Bell, Gerald D.
AU - Benedetti, Angela
AU - Bernhard, Germar
AU - Berrisford, Paul
AU - Berry, David I.
AU - Bhatt, U.
AU - Bidegain, Mario
AU - Bindoff, Nathan
AU - Bissolli, Peter
AU - Blake, Eric S.
AU - Blunden, Jessica
AU - Booneeady, Raj
AU - Bosilovich, Michael
AU - Box, J. E.
AU - Boyer, Tim
AU - Braathen, Geir O.
AU - Bromwich, David H.
AU - Brown, R.
AU - Brown, L.
AU - Bruhwiler, Lori
AU - Bulygina, Olga N.
AU - Burgess, D.
AU - Burrows, John
AU - Calderón, Blanca
AU - Camargo, Suzana J.
AU - Campbell, Jayaka
AU - Cao, Y.
AU - Cappelen, J.
AU - Carrasco, Gualberto
AU - Chambers, Don P.
AU - Chang'A, L.
AU - Chappell, Petra
AU - Chehade, Wissam
AU - Cheliah, Muthuvel
AU - Christiansen, Hanne H.
AU - Christy, John R.
AU - Ciais, Phillipe
AU - Coelho, Caio A.S.
AU - Cogley, J. G.
AU - Colwell, Steve
AU - Cross, J. N.
AU - Crouch, Jake
AU - Cunningham, Stuart A.
AU - Dacic, Milan
AU - De Jeu, Richard A.M.
AU - Dekaa, Francis S.
AU - Demircan, Mesut
AU - Derksen, C.
AU - Diamond, Howard J.
AU - Dlugokencky, Ed J.
AU - Dohan, Kathleen
AU - Dolman, A. Johannes
AU - Domingues, Catia M.
AU - Dong, Shenfu
AU - Dorigo, Wouter A.
AU - Drozdov, D. S.
AU - Duguay, Claude R.
AU - Dunn, Robert J.H.
AU - Dúran-Quesada, Ana M.
AU - Dutton, Geoff S.
AU - Ehmann, Christian
AU - Elkins, James W.
AU - Euscátegui, Christian
AU - Famiglietti, James S.
AU - Fang, Fan
AU - Fauchereau, Nicolas
AU - Feely, Richard A.
AU - Fekete, Balázs M.
AU - Fenimore, Chris
AU - Fioletov, Vitali E.
AU - Fogarty, Chris T.
AU - Fogt, Ryan L.
AU - Folland, Chris K.
AU - Foster, Michael J.
AU - Frajka-Williams, Eleanor
AU - Franz, Bryan A.
AU - Frith, Stacey H.
AU - Frolov, I.
AU - Ganter, Catherine
AU - Garzoli, Silvia
AU - Geai, M. L.
AU - Gerland, S.
AU - Gitau, Wilson
AU - Gleason, Karin L.
AU - Gobron, Nadine
AU - Goldenberg, Stanley B.
AU - Goni, Gustavo
AU - Good, Simon A.
AU - Gottschalck, Jonathan
AU - Gregg, Margarita C.
AU - Griffiths, Georgina
AU - Grooß, Jens Uwe
AU - Guard, Charles Chip
AU - Gupta, Shashi K.
AU - Hall, Bradley D.
AU - Halpert, Michael S.
AU - Harada, Yayoi
AU - Hauri, C.
AU - Heidinger, Andrew K.
AU - Heikkilä, Anu
AU - Heim, Richard R.
AU - Heimbach, Patrick
AU - Hidalgo, Hugo G.
AU - Hilburn, Kyle
AU - Ho, Shu Peng
AU - Hobbs, Will R.
AU - Holgate, Simon
AU - Hovsepyan, Anahit
AU - Hu, Zeng Zhen
AU - Hughes, P.
AU - Hurst, Dale F.
AU - Ingvaldsen, R.
AU - Inness, Antje
AU - Jaimes, Ena
AU - Jakobsson, Martin
AU - James, Adamu I.
AU - Jeffries, Martin O.
AU - Johns, William E.
AU - Johnsen, Bjorn
AU - Johnson, Gregory C.
AU - Johnson, Bryan
AU - Jones, Luke T.
AU - Jumaux, Guillaume
AU - Kabidi, Khadija
AU - Kaiser, Johannes W.
AU - Kamga, Andre
AU - Kang, Kyun Kuk
AU - Kanzow, Torsten O.
AU - Kao, Hsun Ying
AU - Keller, Linda M.
AU - Kennedy, John J.
AU - Key, J.
AU - Khatiwala, Samar
AU - Kheyrollah Pour, H.
AU - Kholodov, A. L.
AU - Khoshkam, Mahbobeh
AU - Kijazi, Agnes
AU - Kikuchi, T.
AU - Kim, B. M.
AU - Kim, S. J.
AU - Kimberlain, Todd B.
AU - Knaff, John A.
AU - Korshunova, Natalia N.
AU - Koskela, T.
AU - Kousky, Vernon E.
AU - Kramarova, Natalya
AU - Kratz, David P.
AU - Krishfield, R.
AU - Kruger, Andries
AU - Kruk, Michael C.
AU - Kumar, Arun
AU - Lagerloef, Gary S.E.
AU - Lakkala, K.
AU - Lander, Mark A.
AU - Landsea, Chris W.
AU - Lankhorst, Matthias
AU - Laurila, T.
AU - Lazzara, Matthew A.
AU - Lee, Craig
AU - Leuliette, Eric
AU - Levitus, Sydney
AU - L'Heureux, Michelle
AU - Lieser, Jan
AU - Lin, I. I.
AU - Liu, Y.
AU - Liu, Y.
AU - Liu, Hongxing
AU - Liu, Yanju
AU - Lobato-Sánchez, Rene
AU - Locarnini, Ricardo
AU - Loeb, Norman G.
AU - Loeng, H.
AU - Long, Craig S.
AU - Lorrey, Andrew M.
AU - Luhunga, P.
AU - Lumpkin, Rick
AU - Luo, Jing Jia
AU - Lyman, John M.
AU - Macdonald, Alison M.
AU - Maddux, Brent C.
AU - Malekela, C.
AU - Manney, Gloria
AU - Marchenko, S. S.
AU - Marengo, Jose A.
AU - Marotzke, Jochem
AU - Marra, John J.
AU - Martínez-Güingla, Rodney
AU - Massom, Robert A.
AU - Mathis, Jeremy T.
AU - McBride, Charlotte
AU - McCarthy, Gerard
AU - McVicar, Tim R.
AU - Mears, Carl
AU - Meier, W.
AU - Meinen, Christopher S.
AU - Menéndez, Melisa
AU - Merrifield, Mark A.
AU - Mitchard, Edward
AU - Mitchum, Gary T.
AU - Montzka, Stephen A.
AU - Morcrette, Jean Jacques
AU - Mote, Thomas
AU - Mühle, Jens
AU - Mühr, Bernhard
AU - Mullan, A. Brett
AU - Müller, Rolf
AU - Nash, Eric R.
AU - Nerem, R. Steven
AU - Newlin, Michele L.
AU - Newman, Paul A.
AU - Ng'Ongolo, H.
AU - Nieto, Juan José
AU - Nishino, S.
AU - Nitsche, Helga
AU - Noetzli, Jeannette
AU - Oberman, N. G.
AU - Obregón, Andre
AU - Ogallo, Laban A.
AU - Oludhe, Christopher S.
AU - Omar, Mohamed I.
AU - Overland, James
AU - Oyunjargal, Lamjav
AU - Parinussa, Robert M.
AU - Park, Geun Ha
AU - Park, E. Hyung
AU - Parker, David
AU - Pasch, Richard J.
AU - Pascual-Ramírez, Reynaldo
AU - Pelto, Mauri S.
AU - Penalba, Olga
AU - Peng, L.
AU - Perovich, Don K.
AU - Pezza, Alexandre B.
AU - Phillips, David
AU - Pickart, R.
AU - Pinty, Bernard
AU - Pitts, Michael C.
AU - Purkey, Sarah G.
AU - Quegan, Shaun
AU - Quintana, Juan
AU - Rabe, B.
AU - Rahimzadeh, Fatemeh
AU - Raholijao, Nirivololona
AU - Raiva, I.
AU - Rajeevan, Madhavan
AU - Ramiandrisoa, Voahanginirina
AU - Ramos, Alexandre
AU - Ranivoarissoa, Sahondra
AU - Rayner, Nick A.
AU - Rayner, Darren
AU - Razuveav, Vyacheslav N.
AU - Reagan, James
AU - Reid, Phillip
AU - Renwick, James
AU - Revedekar, Jayashree
AU - Richter-Menge, Jacqueline
AU - Rivera, Ingrid L.
AU - Robinson, David A.
AU - Rodell, Matthew
AU - Romanovsky, Vladimir E.
AU - Ronchail, Josyane
AU - Rosenlof, Karen H.
AU - Sabine, Christopher L.
AU - Salvador, Mozar A.
AU - Sánchez-Lugo, Ahira
AU - Santee, Michelle L.
AU - Sasgen, I.
AU - Sawaengphokhai, P.
AU - Sayouri, Amal
AU - Scambos, Ted A.
AU - Schauer, U.
AU - Schemm, Jae
AU - Schlosser, P.
AU - Schmid, Claudia
AU - Schreck, Carl
AU - Semiletov, Igor
AU - Send, Uwe
AU - Sensoy, Serhat
AU - Setzer, Alberto
AU - Severinghaus, Jeffrey
AU - Shakhova, Natalia
AU - Sharp, M.
AU - Shiklomanov, Nicolai I.
AU - Siegel, David A.
AU - Silva, Viviane B.S.
AU - Silva, Frabricio D.S.
AU - Sima, Fatou
AU - Simeonov, Petio
AU - Simmonds, I.
AU - Simmons, Adrian
AU - Skansi, Maria
AU - Smeed, David A.
AU - Smethie, W. M.
AU - Smith, Adam B.
AU - Smith, Cathy
AU - Smith, Sharon L.
AU - Smith, Thomas M.
AU - Sokolov, V.
AU - Srivastava, A. K.
AU - Stackhouse, Paul W.
AU - Stammerjohn, Sharon
AU - Steele, M.
AU - Steffen, Konrad
AU - Steinbrecht, Wolfgang
AU - Stephenson, Tannecia
AU - Su, J.
AU - Svendby, T.
AU - Sweet, William
AU - Takahashi, Taro
AU - Tanabe, Raymond M.
AU - Taylor, Michael A.
AU - Tedesco, Marco
AU - Teng, William L.
AU - Thépaut, Jean Noel
AU - Thiaw, Wassila M.
AU - Thoman, R.
AU - Thompson, Philip
AU - Thorne, Peter W.
AU - Timmermans, M. L.
AU - Tobin, Skie
AU - Toole, J.
AU - Trewin, Blair C.
AU - Trigo, Ricardo M.
AU - Trotman, Adrian
AU - Tschudi, M.
AU - Van De Wal, Roderik S.W.
AU - Van Der Werf, Guido R.
AU - Vautard, Robert
AU - Vazquez, J. L.
AU - Vieira, Gonçalo
AU - Vincent, Lucie
AU - Vose, Russ S.
AU - Wagner, Wolfgang W.
AU - Wahr, John
AU - Walsh, J.
AU - Wang, Junhong
AU - Wang, Chunzai
AU - Wang, M.
AU - Wang, Sheng Hung
AU - Wang, Lei
AU - Wanninkhof, Rik
AU - Weaver, Scott
AU - Weber, Mark
AU - Werdell, P. Jeremy
AU - Whitewood, Robert
AU - Wijffels, Susan
AU - Wilber, Anne C.
AU - Wild, J. D.
AU - Willett, Kate M.
AU - Williams, W.
AU - Willis, Joshua K.
AU - Wolken, G.
AU - Wong, Takmeng
AU - Woodgate, R.
AU - Worthy, D.
AU - Wouters, B.
AU - Wovrosh, Alex J.
AU - Xue, Yan
AU - Yamada, Ryuji
AU - Yin, Zungang
AU - Yu, Lisan
AU - Zhang, Liangying
AU - Zhang, Peiqun
AU - Zhao, Lin
AU - Zhao, J.
AU - Zhong, W.
AU - Ziemke, Jerry
AU - Zimmermann, S.
PY - 2013/8
Y1 - 2013/8
N2 - For the first time in several years, the El Nino-Southern Oscillation did not dominate regional climate conditions around the globe. A weak La Niña dissipated to ENSO-neutral conditions by spring, and while El Nino appeared to be emerging during summer, this phase never fully developed as sea surface temperatures in the eastern equatorial Pacific uncharacteristically returned to neutral conditions. Nevertheless, other large-scale climate patterns and extreme weather events impacted various regions during the year. A negative phase of the Arctic Oscillation from mid-January to early February contributed to frigid conditions in parts of northern Africa, eastern Europe, and western Asia. A lack of rain during the 2012 wet season led to the worst drought in at least the past three decades for northeastern Brazil. Central North America also experienced one of its most severe droughts on record. The Caribbean observed a very wet dry season and it was the Sahel's wettest rainy season in 50 years. Overall, the 2012 average temperature across global land and ocean surfaces ranked among the 10 warmest years on record. The global land surface temperature alone was also among the 10 warmest on record. In the upper atmosphere, the average stratospheric temperature was record or near-record cold, depending on the dataset. After a 30-year warming trend from 1970 to 1999 for global sea surface temperatures, the period 2000-12 had little further trend. This may be linked to the prevalence of La Niña-like conditions during the 21st century. Heat content in the upper 700 m of the ocean remained near record high levels in 2012. Net increases from 2011 to 2012 were observed at 700-m to 2000-m depth and even in the abyssal ocean below. Following sharp decreases in global sea level in the first half of 2011 that were linked to the effects of La Niña, sea levels rebounded to reach records highs in 2012. The increased hydrological cycle seen in recent years continued, with more evaporation in drier locations and more precipitation in rainy areas. In a pattern that has held since 2004, salty areas of the ocean surfaces and subsurfaces were anomalously salty on average, while fresher areas were anomalously fresh. Global tropical cyclone activity during 2012 was near average, with a total of 84 storms compared with the 1981-2010 average of 89. Similar to 2010 and 2011, the North Atlantic was the only hurricane basin that experienced above-normal activity. In this basin, Sandy brought devastation to Cuba and parts of the eastern North American seaboard. All other basins experienced either near- or below-normal tropical cyclone activity. Only three tropical cyclones reached Category 5 intensity-all in the Western North Pacific basin. Of these, Super Typhoon Bopha became the only storm in the historical record to produce winds greater than 130 kt south of 7°N. It was also the costliest storm to affect the Philippines and killed more than 1000 residents. Minimum Arctic sea ice extent in September and Northern Hemisphere snow cover extent in June both reached new record lows. June snow cover extent is now declining at a faster rate (-17.6% per decade) than September sea ice extent (-13.0% per decade). Permafrost temperatures reached record high values in northernmost Alaska. A new melt extent record occurred on 11-12 July on the Greenland ice sheet; 97% of the ice sheet showed some form of melt, four times greater than the average melt for this time of year. The climate in Antarctica was relatively stable overall. The largest maximum sea ice extent since records begain in 1978 was observed in September 2012. In the stratosphere, warm air led to the second smallest ozone hole in the past two decades. Even so, the springtime ozone layer above Antarctica likely will not return to its early 1980s state until about 2060. Following a slight decline associated with the global financial crisis, global CO2 emissions from fossil fuel combustion and cement production reached a record 9.5 ± 0.5 Pg C in 2011 and a new record of 9.7 ± 0.5 Pg C is estimated for 2012. Atmospheric CO2 concentrations increased by 2.1 ppm in 2012, to 392.6 ppm. In spring 2012, for the first time, the atmospheric CO2 concentration exceeded 400 ppm at 7 of the 13 Arctic observation sites. Globally, other greenhouse gases including methane and nitrous oxide also continued to rise in concentration and the combined effect now represents a 32% increase in radiative forcing over a 1990 baseline. Concentrations of most ozone depleting substances continued to fall.
AB - For the first time in several years, the El Nino-Southern Oscillation did not dominate regional climate conditions around the globe. A weak La Niña dissipated to ENSO-neutral conditions by spring, and while El Nino appeared to be emerging during summer, this phase never fully developed as sea surface temperatures in the eastern equatorial Pacific uncharacteristically returned to neutral conditions. Nevertheless, other large-scale climate patterns and extreme weather events impacted various regions during the year. A negative phase of the Arctic Oscillation from mid-January to early February contributed to frigid conditions in parts of northern Africa, eastern Europe, and western Asia. A lack of rain during the 2012 wet season led to the worst drought in at least the past three decades for northeastern Brazil. Central North America also experienced one of its most severe droughts on record. The Caribbean observed a very wet dry season and it was the Sahel's wettest rainy season in 50 years. Overall, the 2012 average temperature across global land and ocean surfaces ranked among the 10 warmest years on record. The global land surface temperature alone was also among the 10 warmest on record. In the upper atmosphere, the average stratospheric temperature was record or near-record cold, depending on the dataset. After a 30-year warming trend from 1970 to 1999 for global sea surface temperatures, the period 2000-12 had little further trend. This may be linked to the prevalence of La Niña-like conditions during the 21st century. Heat content in the upper 700 m of the ocean remained near record high levels in 2012. Net increases from 2011 to 2012 were observed at 700-m to 2000-m depth and even in the abyssal ocean below. Following sharp decreases in global sea level in the first half of 2011 that were linked to the effects of La Niña, sea levels rebounded to reach records highs in 2012. The increased hydrological cycle seen in recent years continued, with more evaporation in drier locations and more precipitation in rainy areas. In a pattern that has held since 2004, salty areas of the ocean surfaces and subsurfaces were anomalously salty on average, while fresher areas were anomalously fresh. Global tropical cyclone activity during 2012 was near average, with a total of 84 storms compared with the 1981-2010 average of 89. Similar to 2010 and 2011, the North Atlantic was the only hurricane basin that experienced above-normal activity. In this basin, Sandy brought devastation to Cuba and parts of the eastern North American seaboard. All other basins experienced either near- or below-normal tropical cyclone activity. Only three tropical cyclones reached Category 5 intensity-all in the Western North Pacific basin. Of these, Super Typhoon Bopha became the only storm in the historical record to produce winds greater than 130 kt south of 7°N. It was also the costliest storm to affect the Philippines and killed more than 1000 residents. Minimum Arctic sea ice extent in September and Northern Hemisphere snow cover extent in June both reached new record lows. June snow cover extent is now declining at a faster rate (-17.6% per decade) than September sea ice extent (-13.0% per decade). Permafrost temperatures reached record high values in northernmost Alaska. A new melt extent record occurred on 11-12 July on the Greenland ice sheet; 97% of the ice sheet showed some form of melt, four times greater than the average melt for this time of year. The climate in Antarctica was relatively stable overall. The largest maximum sea ice extent since records begain in 1978 was observed in September 2012. In the stratosphere, warm air led to the second smallest ozone hole in the past two decades. Even so, the springtime ozone layer above Antarctica likely will not return to its early 1980s state until about 2060. Following a slight decline associated with the global financial crisis, global CO2 emissions from fossil fuel combustion and cement production reached a record 9.5 ± 0.5 Pg C in 2011 and a new record of 9.7 ± 0.5 Pg C is estimated for 2012. Atmospheric CO2 concentrations increased by 2.1 ppm in 2012, to 392.6 ppm. In spring 2012, for the first time, the atmospheric CO2 concentration exceeded 400 ppm at 7 of the 13 Arctic observation sites. Globally, other greenhouse gases including methane and nitrous oxide also continued to rise in concentration and the combined effect now represents a 32% increase in radiative forcing over a 1990 baseline. Concentrations of most ozone depleting substances continued to fall.
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U2 - 10.1175/2013BAMSStateoftheClimate.1
DO - 10.1175/2013BAMSStateoftheClimate.1
M3 - Article
AN - SCOPUS:84883271925
VL - 94
JO - Bulletin of the American Meteorological Society
JF - Bulletin of the American Meteorological Society
SN - 0003-0007
IS - 8
ER -