Global Climate

• Published in: Bulletin of the American Meteorological Society
• Main Authors: Dunn, Robert J. H., Aldred, Freya, Gobron, Nadine, Miller, John B., Willett, Kate M., Ades, Melanie, Adler, Robert, Allan, R. P., Anderson, John, Anneville, Orlane, Aono, Yasuyuki, Argüez, Anthony, Arosio, Carlo, Augustine, John A., Azorin-Molina, Cesar, Barichivich, Jonathan, Basu, Aman, Beck, Hylke E., Bellouin, Nicolas, Benedetti, Angela, Blagrave, Kevin, Blenkinsop, Stephen, Bock, Olivier, Bodin, Xavier, Bosilovich, Michael G., Boucher, Olivier, Bove, Gerald, Buechler, Dennis, Buehler, Stefan A., Carrea, Laura, Chang, Kai-Lan, Christiansen, Hanne H., Christy, John R., Chung, Eui-Seok, Ciasto, Laura M., Coldewey-Egbers, Melanie, Cooper, Owen R., Cornes, Richard C., Covey, Curt, Cropper, Thomas, Crotwell, Molly, Cusicanqui, Diego, Davis, Sean M., de Jeu, Richard A. M., Degenstein, Doug, Delaloye, Reynald, Donat, Markus G., Dorigo, Wouter A., Durre, Imke, Dutton, Geoff S.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2022
• Subjects: Antarctic; The Antarctic; Pacific; Indian; Antarc*; North Atlantic; North Atlantic oscillation
• Online Access: http://nora.nerc.ac.uk/id/eprint/533249/; https://nora.nerc.ac.uk/id/eprint/533249/1/%5B15200477%20-%20Bulletin%20of%20the%20American%20Meteorological%20Society%5D%20Global%20Climate.pdf; https://doi.org/10.1175/BAMS-D-22-0092.1

In 2021, both social and economic activities began to return towards the levels preceding the COVID-19 pandemic for some parts of the globe, with others still experiencing restrictions. Meanwhile, the climate has continued to respond to the ongoing increase in greenhouse gases and resulting warming. La Niña, a phenomenon which tends to depress global temperatures while changing rainfall patterns in many regions, prevailed for all but two months of the year. Despite this, 2021 was one of the six-warmest years on record as measured by global mean surface temperature with an anomaly of between +0.21° and +0.28°C above the 1991–2020 climatology. Lake surface temperatures were their highest on record during 2021. The number of warm days over land also reached a new record high. Exceptional heat waves struck the Pacific Coast of North America, leading to a new Canadian maximum temperature of 49.6°C at Lytton, British Columbia, on 29 June, breaking the previous national record by over 4°C. In Death Valley, California, the peak temperature reached 54.4°C on 9 July, equaling the temperature measured in 2020, and the highest temperature recorded anywhere on the globe since at least the 1930s. Over the Mediterranean, a provisional new European record of 48.8°C was set in Sicily on 11 August. In the atmosphere, the annual mean tropospheric temperature was among the 10 highest on record, while the stratosphere continued to cool. While La Niña was present except for June and July, likely influencing Australia’s coolest year since 2012 and wettest since 2016, other modes of variability played important roles. A negative Indian Ocean dipole event became established during July, associated with a warmer east and cooler west Indian Ocean. Northern Hemisphere winters were affected by a negative phase of the North Atlantic Oscillation at both the beginning and end of 2021. In the Southern Hemisphere, a very strong positive Southern Annular Mode (also known as the Antarctic Oscillation) contributed to New Zealand’s record warm year ...