China
Africa
Explore chapters and articles related to this topic
Solar Radiation and Earth's Climate
Published in Robert Ehrlich, Harold A. Geller, John R. Cressman, Renewable Energy, 2023
Robert Ehrlich, Harold A. Geller, John R. Cressman
Finally, another example of a tipping point involves the multistability of the meridional overturning circulation (MOC). The MOC is a network of global oceanic currents produced by a number of forces including thermal and salinity-driven density changes as well as wind and tidal forces. In the northern Atlantic, hot salty water is transported toward the North Pole by the wind-driven gulf stream, an important component of the Atlantic meridional overturning circulation (AMOC). As hot, salty water cools in the northern latitudes it becomes denser and falls through the water column displacing deep water to the south. Another region of recirculation occurs in the southern ocean and this network of surface and deep currents moves and mixes water around the globe. Higher temperatures in the north have led to greater amounts of fresh water from ice sheet and glacial melt, further leading to less dense surface waters and weakened convection. In fact, the Gulf Stream and AMOC have been weakening for the last 150 years and modeling shows that the AMOC has weakened to the point that it may be close to destabilizing. The effects of losing this global conveyer belt are complicated and not well understood however the vast quantities of thermal energy, approximately 25% of the atmospheric and oceanic heat flow, will most certainly effect the climate of the northern Europe and North America.
Copernicus Marine Service Ocean State Report
Published in Journal of Operational Oceanography, 2018
Karina von Schuckmann, Pierre-Yves Le Traon, Neville Smith, Ananda Pascual, Pierre Brasseur, Katja Fennel, Samy Djavidnia, Signe Aaboe, Enrique Alvarez Fanjul, Emmanuelle Autret, Lars Axell, Roland Aznar, Mario Benincasa, Abderahim Bentamy, Fredrik Boberg, Romain Bourdallé-Badie, Bruno Buongiorno Nardelli, Vittorio E. Brando, Clément Bricaud, Lars-Anders Breivik, Robert J.W. Brewin, Arthur Capet, Adrien Ceschin, Stefania Ciliberti, Gianpiero Cossarini, Marta de Alfonso, Alvaro de Pascual Collar, Jos de Kloe, Julie Deshayes, Charles Desportes, Marie Drévillon, Yann Drillet, Riccardo Droghei, Clotilde Dubois, Owen Embury, Hélène Etienne, Claudia Fratianni, Jesús García Lafuente, Marcos Garcia Sotillo, Gilles Garric, Florent Gasparin, Riccardo Gerin, Simon Good, Jérome Gourrion, Marilaure Grégoire, Eric Greiner, Stéphanie Guinehut, Elodie Gutknecht, Fabrice Hernandez, Olga Hernandez, Jacob Høyer, Laura Jackson, Simon Jandt, Simon Josey, Mélanie Juza, John Kennedy, Zoi Kokkini, Gerasimos Korres, Mariliis Kõuts, Priidik Lagemaa, Thomas Lavergne, Bernard le Cann, Jean-François Legeais, Benedicte Lemieux-Dudon, Bruno Levier, Vidar Lien, Ilja Maljutenko, Fernando Manzano, Marta Marcos, Veselka Marinova, Simona Masina, Elena Mauri, Michael Mayer, Angelique Melet, Frédéric Mélin, Benoit Meyssignac, Maeva Monier, Malte Müller, Sandrine Mulet, Cristina Naranjo, Giulio Notarstefano, Aurélien Paulmier, Begoña Pérez Gomez, Irene Pérez Gonzalez, Elisaveta Peneva, Coralie Perruche, K. Andrew Peterson, Nadia Pinardi, Andrea Pisano, Silvia Pardo, Pierre-Marie Poulain, Roshin P. Raj, Urmas Raudsepp, Michaelis Ravdas, Rebecca Reid, Marie-Hélène Rio, Stefano Salon, Annette Samuelsen, Michela Sammartino, Simone Sammartino, Anne Britt Sandø, Rosalia Santoleri, Shubha Sathyendranath, Jun She, Simona Simoncelli, Cosimo Solidoro, Ad Stoffelen, Andrea Storto, Tanguy Szerkely, Susanne Tamm, Steffen Tietsche, Jonathan Tinker, Joaquín Tintore, Ana Trindade, Daphne van Zanten, Luc Vandenbulcke, Anton Verhoef, Nathalie Verbrugge, Lena Viktorsson, Karina von Schuckmann, Sarah L. Wakelin, Anna Zacharioudaki, Hao Zuo
The North Atlantic basin hosts the unique northern hemisphere deep convection regions where most dense water is formed, supplying the deep limb of the Atlantic Meridional Overturning Circulation (AMOC). The latter, controlled by a variety of processes worldwide (Kuhlbrodt et al. 2007), in turn controls the ocean's capability to store heat and anthropogenic carbon. European climate variability is strongly regulated by fluctuations in the intensity and extent of AMOC. While direct observations of the AMOC are limited, monitoring fluctuations of deep convection in the North Atlantic may be useful to picture past, present and future changes in the AMOC. Nevertheless, the North Atlantic is an area with strong ocean-ice–atmosphere interactions, high interannual and decadal variability and its long-term changes in temperature and salinity over the last century are still a matter of debate. After a monotonic decrease of winter convection intensity (often suggested as an indicator of AMOC slowing down) since the mid-1990s (Yashayaev and Loder 2016), intense convection has been reported since 2014. It still remains to be understood if the AMOC intensity is actually decreasing at multidecadal time scales (Terray 2012) or is directly controlled by fluctuations in the Labrador Sea deep convection. In order to contribute to the debate, this section provides an insight on the recent Labrador Sea convective activity and the associated anomalies in hydrographic properties at intermediate depth.