ENSO Impacts in Central Andes El Niño (warm-phase ENSO) is typically associated with warm and sometimes drier conditions, leading to glacier retreat low albedo bare ice is exposed to intense tropical sun at higher temperatures La Niña (cold-phase ENSO) is typically associated with cool and sometimes wetter conditions, leading to glacier advance high albedo fresh snow covers most glacier surfaces, cloud cover is increased, and temperatures are lower

Arctic Oscillation What is the Arctic Oscillation and why is it important?

Arctic Oscillation Seesaw variation in air pressure between the North Pole and middle latitudes Associated changes in the horizontal air pressure gradient alter the speed of the band of winds aloft that blows counterclockwise around the Arctic Impacts middle latitude winter weather and contributes to climate variability Shifts between negative and positive phases © AMS

Arctic Oscillation (AO) “An atmospheric circulation pattern in which the atmospheric pressure over the polar regions varies in opposition with that over middle latitudes (about 45 degrees North) on time scales ranging from weeks to decades.” (NSIDC) Also largely synonymous with the North Atlantic Oscillation (NAO) Negative AO = colder air over mid-latitudes Positive AO = warmer air over mid-latitudes

North Atlantic Oscillation NAO Index varies significantly from one year to the next and from decade to decade Record of the North Atlantic Oscillation (NAO) during winter through 2007-2008 © AMS

Arctic Oscillation (AO) NCDC 2010

Accuweather 2004

Arctic Oscillation Links http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.shtml https://www.aer.com/science-research/climate-weather/arctic-oscillation

NOAA 2011

Pacific Decadal Oscillation “The Pacific Decadal Oscillation (PDO) is a long-lived El Niño-like pattern of Pacific climate variability” (Univ. of Washington 2011) Decadal variations in Pacific SSTs and sea level pressure Warm Phase Cool Phase

Pacific Decadal Oscillation Variations in the Pacific Decadal Oscillation (PDO) Index between warm phases (positive values) and cool phases (negative values), 1900-2014 © AMS

Madden-Julian Oscillation (MJO) Large-scale coupling between atmospheric circulation and tropical deep convection

MJO Links https://www.climate.gov/news-features/blogs/enso/what-mjo-and-why-do-we-care http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/Composites/Temperature/ http://www.atmos.albany.edu/facstaff/roundy/waves/phasediags.html

Warm Arctic Cold Continents Pattern NSF 2010

El Niño-Southern Oscillation North Atlantic Oscillation Late 1970s Climate Shift Pacific Decadal Oscillation “Decadal variations in teleconnections considerably complicate the interpretation of climate change. Since the TAR, it has become clear that a small number of teleconnection patterns account for much of the seasonal to interannual variability in the extratropics” (Trenberth et al. 2007, Chapter 3 of IPCC Physical Science Basis)

Warm-phase of ENSO (El Niño) has accelerated tropical Chacaltaya Glacier, Bolivia Antizana Glacier 15, Ecuador Warm-phase of ENSO (El Niño) has accelerated tropical Andean glacier retreat since the late 1970s 1997-98 Warm-phase ENSO Glacier Recession in Cord. Vilcanota, Peru Francou et al. (2003) Seimon et al. (2007)

Recession of the plateau glaciers on Mt Recession of the plateau glaciers on Mt. Kilimanjaro in East Africa has been primarily a result of less precipitation and more sunshine in association with changes in atmospheric circulation. Kaser et al. (2010) http://www.mountkenyaexpeditions.com/images/mountkilimanjarofromAmboseli.jpg