State of the climate in 2012

Christine Achberger, Stephen A. Ackerman, Adelina Albanil, P. Alexander, Eric J. Alfaro, Rob Allan, Lincoln M. Alves, Jorge A. Amador, Peter Ambenje, Solonomenjanahary Andrianjafinirina, John Antonov, Jose A. Aravequia, A. Arendt, Juan Arévalo, Derek S. Arndt, I. Ashik, Zachary Atheru, Viva Banzon, Molly O. Baringer, Sandra Barreira & 372 others David E. Barriopedro, Grant Beard, Andreas Becker, Michael J. Behrenfeld, Gerald D. Bell, Angela Benedetti, Germar Bernhard, Paul Berrisford, David I. Berry, U. Bhatt, Mario Bidegain, Nathan Bindoff, Peter Bissolli, Eric S. Blake, Jessica Blunden, Raj Booneeady, Michael Bosilovich, J. E. Box, Tim Boyer, Geir O. Braathen, David H. Bromwich, R. Brown, L. Brown, Lori Bruhwiler, Olga N. Bulygina, D. Burgess, John Burrows, Blanca Calderón, Suzana J. Camargo, Jayaka Campbell, Y. Cao, J. Cappelen, Gualberto Carrasco, Don P. Chambers, L. Chang'A, Petra Chappell, Wissam Chehade, Muthuvel Cheliah, Hanne H. Christiansen, John R. Christy, Phillipe Ciais, Caio A.S. Coelho, J. G. Cogley, Steve Colwell, J. N. Cross, Jake Crouch, Stuart A. Cunningham, Milan Dacic, Richard A.M. De Jeu, Francis S. Dekaa, Mesut Demircan, C. Derksen, Howard J. Diamond, Ed J. Dlugokencky, Kathleen Dohan, A. Johannes Dolman, Catia M. Domingues, Shenfu Dong, Wouter A. Dorigo, D. S. Drozdov, Claude R. Duguay, Robert J.H. Dunn, Ana M. Dúran-Quesada, Geoff S. Dutton, Christian Ehmann, James W. Elkins, Christian Euscátegui, James S. Famiglietti, Fan Fang, Nicolas Fauchereau, Richard A. Feely, Balázs M. Fekete, Chris Fenimore, Vitali E. Fioletov, Chris T. Fogarty, Ryan L. Fogt, Chris K. Folland, Michael J. Foster, Eleanor Frajka-Williams, Bryan A. Franz, Stacey H. Frith, I. Frolov, Catherine Ganter, Silvia Garzoli, M. L. Geai, S. Gerland, Wilson Gitau, Karin L. Gleason, Nadine Gobron, Stanley B. Goldenberg, Gustavo Goni, Simon A. Good, Jonathan Gottschalck, Margarita C. Gregg, Georgina Griffiths, Jens Uwe Grooß, Charles Chip Guard, Shashi K. Gupta, Bradley D. Hall, Michael S. Halpert, Yayoi Harada, C. Hauri, Andrew K. Heidinger, Anu Heikkilä, Richard R. Heim, Patrick Heimbach, Hugo G. Hidalgo, Kyle Hilburn, Shu Peng Ho, Will R. Hobbs, Simon Holgate, Anahit Hovsepyan, Zeng Zhen Hu, P. Hughes, Dale F. Hurst, R. Ingvaldsen, Antje Inness, Ena Jaimes, Martin Jakobsson, Adamu I. James, Martin O. Jeffries, William E. Johns, Bjorn Johnsen, Gregory C. Johnson, Bryan Johnson, Luke T. Jones, Guillaume Jumaux, Khadija Kabidi, Johannes W. Kaiser, Andre Kamga, Kyun Kuk Kang, Torsten O. Kanzow, Hsun Ying Kao, Linda M. Keller, John J. Kennedy, J. Key, Samar Khatiwala, H. Kheyrollah Pour, A. L. Kholodov, Mahbobeh Khoshkam, Agnes Kijazi, T. Kikuchi, B. M. Kim, S. J. Kim, Todd B. Kimberlain, John A. Knaff, Natalia N. Korshunova, T. Koskela, Vernon E. Kousky, Natalya Kramarova, David P. Kratz, R. Krishfield, Andries Kruger, Michael C. Kruk, Arun Kumar, Gary S.E. Lagerloef, K. Lakkala, Mark A. Lander, Chris W. Landsea, Matthias Lankhorst, T. Laurila, Matthew A. Lazzara, Craig Lee, Eric Leuliette, Sydney Levitus, Michelle L'Heureux, Jan Lieser, I. I. Lin, Y. Y. Liu, Y. Liu, Hongxing Liu, Yanju Liu, Rene Lobato-Sánchez, Ricardo Locarnini, Norman G. Loeb, H. Loeng, Craig S. Long, Andrew M. Lorrey, P. Luhunga, Rick Lumpkin, Jing Jia Luo, John M. Lyman, Alison M. Macdonald, Brent C. Maddux, C. Malekela, Gloria Manney, S. S. Marchenko, Jose A. Marengo, Jochem Marotzke, John J. Marra, Rodney Martínez-Güingla, Robert A. Massom, Jeremy T. Mathis, Charlotte McBride, Gerard McCarthy, Tim R. McVicar, Carl Mears, W. Meier, Christopher S. Meinen, Melisa Menéndez, Mark A. Merrifield, Edward Mitchard, Gary T. Mitchum, Stephen A. Montzka, Jean Jacques Morcrette, Thomas Mote, Jens Mühle, Bernhard Mühr, A. Brett Mullan, Rolf Müller, Eric R. Nash, R. Steven Nerem, Michele L. Newlin, Paul A. Newman, H. Ng'Ongolo, Juan José Nieto, S. Nishino, Helga Nitsche, Jeannette Noetzli, N. G. Oberman, Andre Obregón, Laban A. Ogallo, Christopher S. Oludhe, Mohamed I. Omar, James Overland, Lamjav Oyunjargal, Robert M. Parinussa, Geun Ha Park, E. Hyung Park, David Parker, Richard J. Pasch, Reynaldo Pascual-Ramírez, Mauri S. Pelto, Olga Penalba, L. Peng, Don K. Perovich, Alexandre B. Pezza, David Phillips, R. Pickart, Bernard Pinty, Michael C. Pitts, Sarah G. Purkey, Shaun Quegan, Juan Quintana, B. Rabe, Fatemeh Rahimzadeh, Nirivololona Raholijao, I. Raiva, Madhavan Rajeevan, Voahanginirina Ramiandrisoa, Alexandre Ramos, Sahondra Ranivoarissoa, Nick A. Rayner, Darren Rayner, Vyacheslav N. Razuveav, James Reagan, Phillip Reid, James Renwick, Jayashree Revedekar, Jacqueline Richter-Menge, Ingrid L. Rivera, David A. Robinson, Matthew Rodell, Vladimir E. Romanovsky, Josyane Ronchail, Karen H. Rosenlof, Christopher L. Sabine, Mozar A. Salvador, Ahira Sánchez-Lugo, Michelle L. Santee, I. Sasgen, P. Sawaengphokhai, Amal Sayouri, Ted A. Scambos, U. Schauer, Jae Schemm, Peter Schlosser, Claudia Schmid, Carl Schreck, Igor Semiletov, Uwe Send, Serhat Sensoy, Alberto Setzer, Jeffrey Severinghaus, Natalia Shakhova, M. Sharp, Nicolai I. Shiklomanov, David A. Siegel, Viviane B.S. Silva, Frabricio D.S. Silva, Fatou Sima, Petio Simeonov, I. Simmonds, Adrian Simmons, Maria Skansi, David A. Smeed, W. M. Smethie, Adam B. Smith, Cathy Smith, Sharon L. Smith, Thomas M. Smith, V. Sokolov, A. K. Srivastava, Paul W. Stackhouse, Sharon Stammerjohn, M. Steele, Konrad Steffen, Wolfgang Steinbrecht, Tannecia Stephenson, J. Su, T. Svendby, William Sweet, Taro Takahashi, Raymond M. Tanabe, Michael A. Taylor, Marco Tedesco, William L. Teng, Jean Noel Thépaut, Wassila M. Thiaw, R. Thoman, Philip Thompson, Peter W. Thorne, M. L. Timmermans, Skie Tobin, J. Toole, Blair C. Trewin, Ricardo M. Trigo, Adrian Trotman, M. Tschudi, Roderik S.W. Van De Wal, Guido R. Van Der Werf, Robert Vautard, J. L. Vazquez, Gonçalo Vieira, Lucie Vincent, Russ S. Vose, Wolfgang W. Wagner, John Wahr, J. Walsh, Junhong Wang, Chunzai Wang, M. Wang, Sheng Hung Wang, Lei Wang, Rik Wanninkhof, Scott Weaver, Mark Weber, P. Jeremy Werdell, Robert Whitewood, Susan Wijffels, Anne C. Wilber, J. D. Wild, Kate M. Willett, W. Williams, Joshua K. Willis, G. Wolken, Takmeng Wong, R. Woodgate, D. Worthy, B. Wouters, Alex J. Wovrosh, Yan Xue, Ryuji Yamada, Zungang Yin, Lisan Yu, Liangying Zhang, Peiqun Zhang, Lin Zhao, J. Zhao, W. Zhong, Jerry Ziemke, S. Zimmermann

Research output: Contribution to journalArticle

63 Citations (Scopus)

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 languageEnglish (US)
JournalBulletin of the American Meteorological Society
Volume94
Issue number8
DOIs
StatePublished - Aug 1 2013
Externally publishedYes

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climate
tropical cyclone
wet season
sea ice
melt
basin
snow cover
new record
El Nino-Southern Oscillation
ice sheet
land surface
sea surface
sea surface temperature
drought
ozone
sea level
Arctic Oscillation
temperature
financial crisis
twenty first century

ASJC Scopus subject areas

  • Atmospheric Science

Cite this

Achberger, C., Ackerman, S. A., Albanil, A., Alexander, P., Alfaro, E. J., Allan, R., ... Zimmermann, S. (2013). State of the climate in 2012. Bulletin of the American Meteorological Society, 94(8). https://doi.org/10.1175/2013BAMSStateoftheClimate.1

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. 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, Peter; 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, 01.08.2013.

Research output: Contribution to journalArticle

Achberger, C, Ackerman, SA, Albanil, A, Alexander, P, Alfaro, EJ, Allan, R, Alves, LM, Amador, JA, Ambenje, P, Andrianjafinirina, S, Antonov, J, Aravequia, JA, Arendt, A, Arévalo, J, Arndt, DS, Ashik, I, Atheru, Z, Banzon, V, Baringer, MO, Barreira, S, Barriopedro, DE, Beard, G, Becker, A, Behrenfeld, MJ, Bell, GD, Benedetti, A, Bernhard, G, Berrisford, P, Berry, DI, Bhatt, U, Bidegain, M, Bindoff, N, Bissolli, P, Blake, ES, Blunden, J, Booneeady, R, Bosilovich, M, Box, JE, Boyer, T, Braathen, GO, Bromwich, DH, Brown, R, Brown, L, Bruhwiler, L, Bulygina, ON, Burgess, D, Burrows, J, Calderón, B, Camargo, SJ, Campbell, J, Cao, Y, Cappelen, J, Carrasco, G, Chambers, DP, Chang'A, L, Chappell, P, Chehade, W, Cheliah, M, Christiansen, HH, Christy, JR, Ciais, P, Coelho, CAS, Cogley, JG, Colwell, S, Cross, JN, Crouch, J, Cunningham, SA, Dacic, M, De Jeu, RAM, Dekaa, FS, Demircan, M, Derksen, C, Diamond, HJ, Dlugokencky, EJ, Dohan, K, Dolman, AJ, Domingues, CM, Dong, S, Dorigo, WA, Drozdov, DS, Duguay, CR, Dunn, RJH, Dúran-Quesada, AM, Dutton, GS, Ehmann, C, Elkins, JW, Euscátegui, C, Famiglietti, JS, Fang, F, Fauchereau, N, Feely, RA, Fekete, BM, Fenimore, C, Fioletov, VE, Fogarty, CT, Fogt, RL, Folland, CK, Foster, MJ, Frajka-Williams, E, Franz, BA, Frith, SH, Frolov, I, Ganter, C, Garzoli, S, Geai, ML, Gerland, S, Gitau, W, Gleason, KL, Gobron, N, Goldenberg, SB, Goni, G, Good, SA, Gottschalck, J, Gregg, MC, Griffiths, G, Grooß, JU, Guard, CC, Gupta, SK, Hall, BD, Halpert, MS, Harada, Y, Hauri, C, Heidinger, AK, Heikkilä, A, Heim, RR, Heimbach, P, Hidalgo, HG, Hilburn, K, Ho, SP, Hobbs, WR, Holgate, S, Hovsepyan, A, Hu, ZZ, Hughes, P, Hurst, DF, Ingvaldsen, R, Inness, A, Jaimes, E, Jakobsson, M, James, AI, Jeffries, MO, Johns, WE, Johnsen, B, Johnson, GC, Johnson, B, Jones, LT, Jumaux, G, Kabidi, K, Kaiser, JW, Kamga, A, Kang, KK, Kanzow, TO, Kao, HY, Keller, LM, Kennedy, JJ, Key, J, Khatiwala, S, Kheyrollah Pour, H, Kholodov, AL, Khoshkam, M, Kijazi, A, Kikuchi, T, Kim, BM, Kim, SJ, Kimberlain, TB, Knaff, JA, Korshunova, NN, Koskela, T, Kousky, VE, Kramarova, N, Kratz, DP, Krishfield, R, Kruger, A, Kruk, MC, Kumar, A, Lagerloef, GSE, Lakkala, K, Lander, MA, Landsea, CW, Lankhorst, M, Laurila, T, Lazzara, MA, Lee, C, Leuliette, E, Levitus, S, L'Heureux, M, Lieser, J, Lin, II, Liu, YY, Liu, Y, Liu, H, Liu, Y, Lobato-Sánchez, R, Locarnini, R, Loeb, NG, Loeng, H, Long, CS, Lorrey, AM, Luhunga, P, Lumpkin, R, Luo, JJ, Lyman, JM, Macdonald, AM, Maddux, BC, Malekela, C, Manney, G, Marchenko, SS, Marengo, JA, Marotzke, J, Marra, JJ, Martínez-Güingla, R, Massom, RA, Mathis, JT, McBride, C, McCarthy, G, McVicar, TR, Mears, C, Meier, W, Meinen, CS, Menéndez, M, Merrifield, MA, Mitchard, E, Mitchum, GT, Montzka, SA, Morcrette, JJ, Mote, T, Mühle, J, Mühr, B, Mullan, AB, Müller, R, Nash, ER, Nerem, RS, Newlin, ML, Newman, PA, Ng'Ongolo, H, Nieto, JJ, Nishino, S, Nitsche, H, Noetzli, J, Oberman, NG, Obregón, A, Ogallo, LA, Oludhe, CS, Omar, MI, Overland, J, Oyunjargal, L, Parinussa, RM, Park, GH, Park, EH, Parker, D, Pasch, RJ, Pascual-Ramírez, R, Pelto, MS, Penalba, O, Peng, L, Perovich, DK, Pezza, AB, Phillips, D, Pickart, R, Pinty, B, Pitts, MC, Purkey, SG, Quegan, S, Quintana, J, Rabe, B, Rahimzadeh, F, Raholijao, N, Raiva, I, Rajeevan, M, Ramiandrisoa, V, Ramos, A, Ranivoarissoa, S, Rayner, NA, Rayner, D, Razuveav, VN, Reagan, J, Reid, P, Renwick, J, Revedekar, J, Richter-Menge, J, Rivera, IL, Robinson, DA, Rodell, M, Romanovsky, VE, Ronchail, J, Rosenlof, KH, Sabine, CL, Salvador, MA, Sánchez-Lugo, A, Santee, ML, Sasgen, I, Sawaengphokhai, P, Sayouri, A, Scambos, TA, Schauer, U, Schemm, J, Schlosser, P, Schmid, C, Schreck, C, Semiletov, I, Send, U, Sensoy, S, Setzer, A, Severinghaus, J, Shakhova, N, Sharp, M, Shiklomanov, NI, Siegel, DA, Silva, VBS, Silva, FDS, Sima, F, Simeonov, P, Simmonds, I, Simmons, A, Skansi, M, Smeed, DA, Smethie, WM, Smith, AB, Smith, C, Smith, SL, Smith, TM, Sokolov, V, Srivastava, AK, Stackhouse, PW, Stammerjohn, S, Steele, M, Steffen, K, Steinbrecht, W, Stephenson, T, Su, J, Svendby, T, Sweet, W, Takahashi, T, Tanabe, RM, Taylor, MA, Tedesco, M, Teng, WL, Thépaut, JN, Thiaw, WM, Thoman, R, Thompson, P, Thorne, PW, Timmermans, ML, Tobin, S, Toole, J, Trewin, BC, Trigo, RM, Trotman, A, Tschudi, M, Van De Wal, RSW, Van Der Werf, GR, Vautard, R, Vazquez, JL, Vieira, G, Vincent, L, Vose, RS, Wagner, WW, Wahr, J, Walsh, J, Wang, J, Wang, C, Wang, M, Wang, SH, Wang, L, Wanninkhof, R, Weaver, S, Weber, M, Werdell, PJ, Whitewood, R, Wijffels, S, Wilber, AC, Wild, JD, Willett, KM, Williams, W, Willis, JK, Wolken, G, Wong, T, Woodgate, R, Worthy, D, Wouters, B, Wovrosh, AJ, Xue, Y, Yamada, R, Yin, Z, Yu, L, Zhang, L, Zhang, P, Zhao, L, Zhao, J, Zhong, W, Ziemke, J & Zimmermann, S 2013, 'State of the climate in 2012', Bulletin of the American Meteorological Society, vol. 94, no. 8. https://doi.org/10.1175/2013BAMSStateoftheClimate.1
Achberger C, Ackerman SA, Albanil A, Alexander P, Alfaro EJ, Allan R et al. State of the climate in 2012. Bulletin of the American Meteorological Society. 2013 Aug 1;94(8). https://doi.org/10.1175/2013BAMSStateoftheClimate.1
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. 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, Peter ; 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. / State of the climate in 2012. In: Bulletin of the American Meteorological Society. 2013 ; Vol. 94, No. 8.
@article{fb040edf3c05488db43b6b99842698f5,
title = "State of the climate in 2012",
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 Ni{\~n}a 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 Ni{\~n}a-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 Ni{\~n}a, 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.",
author = "Christine Achberger and Ackerman, {Stephen A.} and Adelina Albanil and P. Alexander and Alfaro, {Eric J.} and Rob Allan and Alves, {Lincoln M.} and Amador, {Jorge A.} and Peter Ambenje and Solonomenjanahary Andrianjafinirina and John Antonov and Aravequia, {Jose A.} and A. Arendt and Juan Ar{\'e}valo and Arndt, {Derek S.} and I. Ashik and Zachary Atheru and Viva Banzon and Baringer, {Molly O.} and Sandra Barreira and Barriopedro, {David E.} and Grant Beard and Andreas Becker and Behrenfeld, {Michael J.} and Bell, {Gerald D.} and Angela Benedetti and Germar Bernhard and Paul Berrisford and Berry, {David I.} and U. Bhatt and Mario Bidegain and Nathan Bindoff and Peter Bissolli and Blake, {Eric S.} and Jessica Blunden and Raj Booneeady and Michael Bosilovich and Box, {J. E.} and Tim Boyer and Braathen, {Geir O.} and Bromwich, {David H.} and R. Brown and L. Brown and Lori Bruhwiler and Bulygina, {Olga N.} and D. Burgess and John Burrows and Blanca Calder{\'o}n and Camargo, {Suzana J.} and Jayaka Campbell and Y. Cao and J. Cappelen and Gualberto Carrasco and Chambers, {Don P.} and L. Chang'A and Petra Chappell and Wissam Chehade and Muthuvel Cheliah and Christiansen, {Hanne H.} and Christy, {John R.} and Phillipe Ciais and Coelho, {Caio A.S.} and Cogley, {J. G.} and Steve Colwell and Cross, {J. N.} and Jake Crouch and Cunningham, {Stuart A.} and Milan Dacic and {De Jeu}, {Richard A.M.} and Dekaa, {Francis S.} and Mesut Demircan and C. Derksen and Diamond, {Howard J.} and Dlugokencky, {Ed J.} and Kathleen Dohan and Dolman, {A. Johannes} and Domingues, {Catia M.} and Shenfu Dong and Dorigo, {Wouter A.} and Drozdov, {D. S.} and Duguay, {Claude R.} and Dunn, {Robert J.H.} and D{\'u}ran-Quesada, {Ana M.} and Dutton, {Geoff S.} and Christian Ehmann and Elkins, {James W.} and Christian Eusc{\'a}tegui and Famiglietti, {James S.} and Fan Fang and Nicolas Fauchereau and Feely, {Richard A.} and Fekete, {Bal{\'a}zs M.} and Chris Fenimore and Fioletov, {Vitali E.} and Fogarty, {Chris T.} and Fogt, {Ryan L.} and Folland, {Chris K.} and Foster, {Michael J.} and Eleanor Frajka-Williams and Franz, {Bryan A.} and Frith, {Stacey H.} and I. Frolov and Catherine Ganter and Silvia Garzoli and Geai, {M. L.} and S. Gerland and Wilson Gitau and Gleason, {Karin L.} and Nadine Gobron and Goldenberg, {Stanley B.} and Gustavo Goni and Good, {Simon A.} and Jonathan Gottschalck and Gregg, {Margarita C.} and Georgina Griffiths and Groo{\ss}, {Jens Uwe} and Guard, {Charles Chip} and Gupta, {Shashi K.} and Hall, {Bradley D.} and Halpert, {Michael S.} and Yayoi Harada and C. Hauri and Heidinger, {Andrew K.} and Anu Heikkil{\"a} and Heim, {Richard R.} and Patrick Heimbach and Hidalgo, {Hugo G.} and Kyle Hilburn and Ho, {Shu Peng} and Hobbs, {Will R.} and Simon Holgate and Anahit Hovsepyan and Hu, {Zeng Zhen} and P. Hughes and Hurst, {Dale F.} and R. Ingvaldsen and Antje Inness and Ena Jaimes and Martin Jakobsson and James, {Adamu I.} and Jeffries, {Martin O.} and Johns, {William E.} and Bjorn Johnsen and Johnson, {Gregory C.} and Bryan Johnson and Jones, {Luke T.} and Guillaume Jumaux and Khadija Kabidi and Kaiser, {Johannes W.} and Andre Kamga and Kang, {Kyun Kuk} and Kanzow, {Torsten O.} and Kao, {Hsun Ying} and Keller, {Linda M.} and Kennedy, {John J.} and J. Key and Samar Khatiwala and {Kheyrollah Pour}, H. and Kholodov, {A. L.} and Mahbobeh Khoshkam and Agnes Kijazi and T. Kikuchi and Kim, {B. M.} and Kim, {S. J.} and Kimberlain, {Todd B.} and Knaff, {John A.} and Korshunova, {Natalia N.} and T. Koskela and Kousky, {Vernon E.} and Natalya Kramarova and Kratz, {David P.} and R. Krishfield and Andries Kruger and Kruk, {Michael C.} and Arun Kumar and Lagerloef, {Gary S.E.} and K. Lakkala and Lander, {Mark A.} and Landsea, {Chris W.} and Matthias Lankhorst and T. Laurila and Lazzara, {Matthew A.} and Craig Lee and Eric Leuliette and Sydney Levitus and Michelle L'Heureux and Jan Lieser and Lin, {I. I.} and Liu, {Y. Y.} and Y. Liu and Hongxing Liu and Yanju Liu and Rene Lobato-S{\'a}nchez and Ricardo Locarnini and Loeb, {Norman G.} and H. Loeng and Long, {Craig S.} and Lorrey, {Andrew M.} and P. Luhunga and Rick Lumpkin and Luo, {Jing Jia} and Lyman, {John M.} and Macdonald, {Alison M.} and Maddux, {Brent C.} and C. Malekela and Gloria Manney and Marchenko, {S. S.} and Marengo, {Jose A.} and Jochem Marotzke and Marra, {John J.} and Rodney Mart{\'i}nez-G{\"u}ingla and Massom, {Robert A.} and Mathis, {Jeremy T.} and Charlotte McBride and Gerard McCarthy and McVicar, {Tim R.} and Carl Mears and W. Meier and Meinen, {Christopher S.} and Melisa Men{\'e}ndez and Merrifield, {Mark A.} and Edward Mitchard and Mitchum, {Gary T.} and Montzka, {Stephen A.} and Morcrette, {Jean Jacques} and Thomas Mote and Jens M{\"u}hle and Bernhard M{\"u}hr and Mullan, {A. Brett} and Rolf M{\"u}ller and Nash, {Eric R.} and Nerem, {R. Steven} and Newlin, {Michele L.} and Newman, {Paul A.} and H. Ng'Ongolo and Nieto, {Juan Jos{\'e}} and S. Nishino and Helga Nitsche and Jeannette Noetzli and Oberman, {N. G.} and Andre Obreg{\'o}n and Ogallo, {Laban A.} and Oludhe, {Christopher S.} and Omar, {Mohamed I.} and James Overland and Lamjav Oyunjargal and Parinussa, {Robert M.} and Park, {Geun Ha} and Park, {E. Hyung} and David Parker and Pasch, {Richard J.} and Reynaldo Pascual-Ram{\'i}rez and Pelto, {Mauri S.} and Olga Penalba and L. Peng and Perovich, {Don K.} and Pezza, {Alexandre B.} and David Phillips and R. Pickart and Bernard Pinty and Pitts, {Michael C.} and Purkey, {Sarah G.} and Shaun Quegan and Juan Quintana and B. Rabe and Fatemeh Rahimzadeh and Nirivololona Raholijao and I. Raiva and Madhavan Rajeevan and Voahanginirina Ramiandrisoa and Alexandre Ramos and Sahondra Ranivoarissoa and Rayner, {Nick A.} and Darren Rayner and Razuveav, {Vyacheslav N.} and James Reagan and Phillip Reid and James Renwick and Jayashree Revedekar and Jacqueline Richter-Menge and Rivera, {Ingrid L.} and Robinson, {David A.} and Matthew Rodell and Romanovsky, {Vladimir E.} and Josyane Ronchail and Rosenlof, {Karen H.} and Sabine, {Christopher L.} and Salvador, {Mozar A.} and Ahira S{\'a}nchez-Lugo and Santee, {Michelle L.} and I. Sasgen and P. Sawaengphokhai and Amal Sayouri and Scambos, {Ted A.} and U. Schauer and Jae Schemm and Peter Schlosser and Claudia Schmid and Carl Schreck and Igor Semiletov and Uwe Send and Serhat Sensoy and Alberto Setzer and Jeffrey Severinghaus and Natalia Shakhova and M. Sharp and Shiklomanov, {Nicolai I.} and Siegel, {David A.} and Silva, {Viviane B.S.} and Silva, {Frabricio D.S.} and Fatou Sima and Petio Simeonov and I. Simmonds and Adrian Simmons and Maria Skansi and Smeed, {David A.} and Smethie, {W. M.} and Smith, {Adam B.} and Cathy Smith and Smith, {Sharon L.} and Smith, {Thomas M.} and V. Sokolov and Srivastava, {A. K.} and Stackhouse, {Paul W.} and Sharon Stammerjohn and M. Steele and Konrad Steffen and Wolfgang Steinbrecht and Tannecia Stephenson and J. Su and T. Svendby and William Sweet and Taro Takahashi and Tanabe, {Raymond M.} and Taylor, {Michael A.} and Marco Tedesco and Teng, {William L.} and Th{\'e}paut, {Jean Noel} and Thiaw, {Wassila M.} and R. Thoman and Philip Thompson and Thorne, {Peter W.} and Timmermans, {M. L.} and Skie Tobin and J. Toole and Trewin, {Blair C.} and Trigo, {Ricardo M.} and Adrian Trotman and M. Tschudi and {Van De Wal}, {Roderik S.W.} and {Van Der Werf}, {Guido R.} and Robert Vautard and Vazquez, {J. L.} and Gon{\cc}alo Vieira and Lucie Vincent and Vose, {Russ S.} and Wagner, {Wolfgang W.} and John Wahr and J. Walsh and Junhong Wang and Chunzai Wang and M. Wang and Wang, {Sheng Hung} and Lei Wang and Rik Wanninkhof and Scott Weaver and Mark Weber and Werdell, {P. Jeremy} and Robert Whitewood and Susan Wijffels and Wilber, {Anne C.} and Wild, {J. D.} and Willett, {Kate M.} and W. Williams and Willis, {Joshua K.} and G. Wolken and Takmeng Wong and R. Woodgate and D. Worthy and B. Wouters and Wovrosh, {Alex J.} and Yan Xue and Ryuji Yamada and Zungang Yin and Lisan Yu and Liangying Zhang and Peiqun Zhang and Lin Zhao and J. Zhao and W. Zhong and Jerry Ziemke and S. Zimmermann",
year = "2013",
month = "8",
day = "1",
doi = "10.1175/2013BAMSStateoftheClimate.1",
language = "English (US)",
volume = "94",
journal = "Bulletin of the American Meteorological Society",
issn = "1087-3562",
publisher = "American Meteorological Society",
number = "8",

}

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. 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, Peter

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 - 2013/8/1

Y1 - 2013/8/1

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.

UR - http://www.scopus.com/inward/record.url?scp=84883271925&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84883271925&partnerID=8YFLogxK

U2 - 10.1175/2013BAMSStateoftheClimate.1

DO - 10.1175/2013BAMSStateoftheClimate.1

M3 - Article

VL - 94

JO - Bulletin of the American Meteorological Society

JF - Bulletin of the American Meteorological Society

SN - 1087-3562

IS - 8

ER -