Search

Your search keyword '"Folland, Chris K."' showing total 140 results
Start Over Author "Folland, Chris K."
140 results on '"Folland, Chris K."'

1. The Summer North Atlantic Oscillation, Arctic sea ice, and Arctic jet Rossby wave forcing.

Author

Folland, Chris K., Tinghai Ou, Linderholm, Hans W., Scaife, Adam A., Knight, Jeff, and Deliang Chen

Subjects
*NORTH Atlantic oscillation, *SEA ice, *ROSSBY waves, *WAVE forces, *ATMOSPHERIC circulation, *ARCTIC oscillation
Abstract

We use Coupled Model Intercomparison Project Phase 6 (CMIP6) coupled and Atmospheric Model Intercomparison Project (AMIP) climate models, dynamical analyses, and observations to investigate interactions between summer Arctic sea ice concentration (SIC) variations and the Summer North Atlantic Oscillation (SNAO). Observations suggest that SIC-SNAO relationships mainly come from the East Siberian to Arctic Canada (ESAC) region where a weak atmospheric jet stream exists in summer. Twelve CMIP6 models with the most realistic atmospheric climatologies over the North Atlantic and Europe agree well with reanalyses on relationships between SIC and Northern Hemisphere atmospheric circulation. CMIP6 model data indicate that ESAC SIC influences the SNAO with a lead time of several weeks. However, AMIP simulations do not reproduce the observed atmospheric circulation when observed sea ice is prescribed. Rossby wave analyses do though support observed ESAC SIC influences on the SNAO. We conclude that ESAC Arctic SIC modestly influences the SNAO, and such investigations require the use of coupled models. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

2. Why Does the Ensemble Mean of CMIP6 Models Simulate Arctic Temperature More Accurately Than Global Temperature?

Author

Chylek, Petr, Folland, Chris K., Klett, James D., Wang, Muyin, Lesins, Glen, and Dubey, Manvendra K.

Subjects
*GLOBAL warming, *ATMOSPHERIC models, *ATMOSPHERIC temperature, *TUNDRAS, *CLIMATE change, *SURFACE temperature
Abstract

An accurate simulation and projection of future warming are needed for a proper policy response to expected climate change. We examine the simulations of the mean global and Arctic surface air temperatures by the CMIP6 (Climate Models Intercomparison Project phase 6) climate models. Most models overestimate the observed mean global warming. Only seven out of 19 models considered simulate global warming that is within ±15% of the observed warming between the average of the 2014–2023 and 1961–1990 reference period. Ten models overestimate global warming by more than 15% and only one of the models underestimates it by more than 15%. Arctic warming is simulated by the CMIP6 climate models much better than the mean global warming. The reason is an equal spread of over and underestimates of Arctic warming by the models, while most of the models overestimate the mean global warming. Eight models are within ±15% of the observed Arctic warming. Only three models are accurate within ±15% for both mean global and Arctic temperature simulations. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

3. Global Warming and the Next Ice Age

Author

Dubey, Manvendra K, Chylek, Petr, Zender, Charlie S, and Folland, Chris K

Subjects
Astronomical and Space Sciences, Atmospheric Sciences, Physical Geography and Environmental Geoscience, Meteorology & Atmospheric Sciences
Abstract

The Second International Conference on Global Warming and the Next Ice Age (GWNIA) held in Halifax, Nova Scotia, aimed to provide a venue for detaile discussions regarding how the Earth's climate is responding to an array of forcings, such as anthropogenic carbon dioxide and aerosols, and solar variability besides long-lived greenhouse gases (GHGs). The conference discussed the shortcomings of current models, observations, and theory, and developed a path toward using observational data refining these models. Meanwhile, the understanding and reducing climate prediction uncertainties caused by anthropogenic aerosol forcing were the focused on the second half of the conference.

Published
2008

4. High Values of the Arctic Amplification in the Early Decades of the 21st Century: Causes of Discrepancy by CMIP6 Models Between Observation and Simulation.

Author

Chylek, Petr, Folland, Chris K., Klett, James D., Wang, Muyin, Lesins, Glen, and Dubey, Manvendra K.

Subjects
TWENTY-first century, ATMOSPHERIC models, GLOBAL warming, SPRING, TWENTIETH century, TUNDRAS
Abstract

Arctic Amplification (AA) in the first decade of the 21st century has reached values between 4 and 5, with a subsequent decrease to current values of about 3.6, while the value was from 2 to 3 during the twentieth century. The ensemble mean of the CMIP6 models has difficulty in reproducing the recently observed high values of the AA. In this report, we identify the main reason for this difficulty to be the CMIP6 models overestimate of the mean global temperature trend since about 1990. The largest values of the AA are observed in winter and spring. A sharp AA peak in 1987 spring was caused by a peak in the Arctic temperature trend occurring at the same time as a dip in the trend of mean global temperature. The winter AA has increased almost monotonically since 1990. Dividing the AA between the Arctic land and ocean areas shows that the ocean area makes a larger contribution to the AA. Our future projection of the AA suggests an increasing AA for about the next decade, followed by a slow decrease to about 3.5 in the 2050s. Plain Language Summary: The Arctic is warming faster than the average warming of the whole earth. The Arctic Amplification (AA) is defined as the ratio of the Arctic to global mean warming rates. Thus, the AA increases when the rate of Arctic warming increases, when the rate of global warming decreases, or when both happen at the same time. For most of the twentieth century, the AA was between 2 and 3. However, during the first few years of the 21st century, the AA has reached over four. The current climate models are not able to reproduce the observed early 21st‐century high values of AA. We find that the main reason for this difficulty is the models' overestimate of the global warming rates after 1990. Key Points: The early 21st century high values of the AA are caused by a higher temperature trend over the Arctic and a lower global temperature trendThe CMIP6 models' difficulty in reproducing the observed AA is due to the models' overestimate of the rate of mean global warming after 1990The future projection of the AA suggests an increasing AA for about the next decade with a slowly decreasing trend after that [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

10. THE NEED FOR A DYNAMICAL CLIMATE REANALYSIS

Author

Bengtsson, Lennart, Arkin, Phil, Berrisford, Paul, Bougeault, Philippe, Folland, Chris K., Gordon, Chris, Haines, Keith, Hodges, Kevin I., Jones, Phil, Kallberg, Per, Rayner, Nick, Simmons, Adrian J., Stammer, Detlef, Thorne, Peter W., Uppala, Sakari, and Vose, Russell S.

Published
2007

11. VERTICAL PROFILES OF TEMPERATURE TRENDS

Author

Thorne, Peter W., Karl, Thomas R., Coleman, Holly, Folland, Chris K., Murray, Bill, Parker, David E., Ramaswamy, V., Rossow, William, Scaife, Adam A., and Tett, Simon F. B.

Published
2005

22. Pen portraits of Presidents – Professor Raymond Hide, CBE, ScD, FRS.

Author

Folland, Chris K. and Read, Peter L.

Subjects
*GEOPHYSICAL fluid dynamics, *PLASMA physics, *ROTATING fluid, *GEOPHYSICS, *JET streams, *EDDIES
Abstract

We describe the life and scientific accomplishments of Professor Raymond Hide. It is clear from Hide (2010) that Raymond was much inspired by the seminal early work on non-linear dynamics related to atmospheric predictability, vacillation and deterministic chaos carried out while he was at MIT by Ed Lorenz. A summary of Raymond Hide's life Raymond received a very impressive series of national and international awards and leadership appointments across geophysics. This was also the advent of the era of space exploration and Raymond was early to appreciate the potential of spacecraft to explore the dynamics of the atmospheres and interiors of the planets (e.g. Hide, 1966b) though he was never to take up a formal role in specific projects, probably because of the bureaucracy involved. [Extracted from the article]

Published
2022
Full Text
View/download PDF

28. Pen portraits of Presidents – Sir Basil John Mason, CB, DSc, FRS.

Author

Folland, Chris K. and Mitchell, John F. B.

Subjects
*CLOUD physics, *PORTRAITS, *BASIL, *PENS, *CLIMATE change
Abstract

We present a short biography of Sir John Mason, part of Weather's series of pen portraits of Past Presidents of the Royal Meteorological Society. This biography is longer than a normal pen portrait to reflect Sir John Mason's exceptional and wide‐ranging achievements and to show how he contributed to the debate about climate change. We include a discussion of his early years, particularly his pioneering work in cloud physics. We particularly review the key activities of the Met Office with which he was closely involved in his years as Director General, followed by his activities after retirement and his main awards. [ABSTRACT FROM AUTHOR]

Published
2020
Full Text
View/download PDF

33. Changes in the future summer Mediterranean climate: contribution of teleconnections and local factors.

Author

Barcikowska, Monika J., Kapnick, Sarah B., Krishnamurty, Lakshmi, Russo, Simone, Cherchi, Annalisa, and Folland, Chris K.

Subjects
MEDITERRANEAN climate, TELECONNECTIONS (Climatology), GEOPHYSICAL fluid dynamics, LAND-atmosphere interactions, ATMOSPHERIC circulation, NORTH Atlantic oscillation
Abstract

Abstract. The realistic simulation of the summer Mediterranean climate requires not only refined spatial scales, but also an adequate representation of land-atmosphere interactions and teleconnections. Addressing all of these issues remains a challenge for most of the CMIP3/CMIP5 generation models. In this study we analyze high-resolution (~0.5° lat x lon) RCP8.5 future projections of the Geophysical Fluid Dynamics Laboratory CM2.5 model with a new incorporated land model (LM3). The simulated regional future changes suggest pronounced warming and drying over most parts of the Mediterranean. However the changes are distinctively less radical when compared with the CMIP5 multimodel ensemble. Moreover, changes over the Southeast (off the coast area of the Balkans) and Central Europe indicate not only a very modest warming, compared to the CMIP5 projections, but also wetting tendencies. The difference of CM2.5 projections of future changes over previous-generation models highlights the importance of a) a correctly projected magnitude of changes of the North Atlantic Oscillation and its regional impacts, which have the capacity to partly offset the anthropogenic warming and drying over the western and central Mediterranean; b) a refined representation of land surface-atmospheric interactions, which are a governing factor for thermal- and hydro-climate over Central and Southeastern Europe. The CM2.5 projections also indicate a maximum of warming (Levant) and drying (Asia Minor) over the eastern Mediterranean. The changes derived in this region indicate a decreasing influence of atmospheric dynamics in maintaining the regional temperature and precipitation balance and instead an increasing influence of local surface temperature on the local surface atmospheric circulation. [ABSTRACT FROM AUTHOR]

Published
2019
Full Text
View/download PDF

34. State of the Climate in 2012

Author

Blunden, Jessica, Arndt, Derek S., 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., Arevalo, Juan, 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., 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, Calderon, 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, 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., Duran-Quesada, Ana M., Dutton, Geoff S., Ehmann, Christian, Elkins, James W., Euscategui, Christian, Famiglietti, James S., Fang Fan, Fauchereau, Nicolas, Feely, Richard A., Fekete, Balazs 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., Heikkila, 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, Pour, H. Kheyrollah, 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-Sanchez, 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., Martinez-Gueingla, Rodney, Massom, Robert A., Mathis, Jeremy T., Mcbride, Charlotte, Mccarthy, Gerard, Mcvicar, Tim R., Mears, Carl, Meier, W., Meinen, Christopher S., Menendez, Melisa, Merrifield, Mark A., Mitchard, Edward, Mitchum, Gary T., Montzka, Stephen A., Morcrette, Jean-Jacques, Mote, Thomas, Muehle, Jens, Muehr, Bernhard, Mullan, A. Brett, Mueller, Rolf, Nash, Eric R., Nerem, R. Steven, Newlin, Michele L., Newman, Paul A., Ng Ongolo, H., Nieto, Juan Jose, Nishino, S., Nitsche, Helga, Noetzli, Jeannette, Oberman, N. G., Obregon, Andre, Ogallo, Laban A., Oludhe, Christopher S., Omar, Mohamed I., Overland, James, Oyunjargal, Lamjav, Parinussa, Robert M., Park, Geun-Ha, Park, E-Hyung, David Berry, Pasch, Richard J., Pascual-Ramirez, 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., Sanchez-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., Thepaut, 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., Wal, Roderik S. W., Werf, Guido R., Vautard, Robert, Vazquez, J. L., Vieira, Goncalo, 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., ICOS-ATC (ICOS-ATC), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Extrèmes : Statistiques, Impacts et Régionalisation (ESTIMR), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), and Repositório da Universidade de Lisboa

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Atmospheric Science, 13. Climate action, Photosynthetically active radiation, Climate, Dynamics (mechanics), Data_FILES, Environmental science, Fraction (chemistry), 14. Life underwater, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Remote sensing
Abstract

For the first time in serveral years, the El Nino-Southern Oscillation did not dominate regional climate conditions around the globe. A weak La Ni a dissipated to ENSOneutral 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 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 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 to the effects of La Ni 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 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 2 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, 2 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.

Published
2013
Full Text
View/download PDF

37. Multi-annual droughts in the water-stressed English lowlands: long-term variability and climate drivers

Author

Daniell, Trevor M., Hannaford, Jamie, Folland, Chris K., Kendon, Mike C., Bloomfield, John P., Daniell, Trevor M., Hannaford, Jamie, Folland, Chris K., Kendon, Mike C., and Bloomfield, John P.

Abstract

The English Lowlands is the most populated part of the UK, and parts of the region are already water-stressed. The region is heavily dependent on groundwater resources, and is thus vulnerable to long, multi-annual drought episodes that include dry winters (winter being the time groundwater is replenished). This study uses a range of meteorological and hydrological datasets to characterise multi-annual droughts in the region from 1910 to 2012. As a prelude to a wider study of climate drivers affecting these historical long droughts, the role of ENSO in affecting dry winters in the English Lowlands is investigated. Many historical long droughts are associated with La Nińa episodes, although the relationship is complex and more work is required to disentangle the many climatic drivers of multi-annual droughts in this region.

Published
2014

38. Vertical profiles of temperature trends

Author

Thorne, Peter, Karl, Thomas R., Coleman, Holly, Folland, Chris K., Murray, Bill, Parker, David E., Ramaswamy, Venkatachalam, Rossow, William, Scaife, Adam A., and Tett, Simon F.B.

Abstract

No abstract available

Published
2005

39. Biases in satellite-derived sea-surface-temperature data

Author

Reynolds, Richard W., Folland, Chris K., and Parker, David E.

Subjects
Global warming -- Research, Scientific satellites -- Evaluation, Environmental issues, Science and technology, Zoology and wildlife conservation
Published
1989

Catalog

Books, media, physical & digital resources
See catalog results