Climate Variability, El Nino and Southern Oscillation and a Very Preliminary Summer Outlook. Anthony R. Lupo, Professor Department of Soil, Environmental, and Atmospheric Science 302 ABNR Building University of Missouri Columbia, MO 65211

Introduction Climate Change has become an important issue for society to confront. We can’t avoid it… It is believed (in some quarters) much or all of the increase since the mid-19th century is due solely to human activities.

Introduction Global climate has been steady for the last 18 years, in spite of the continuous increase in atmospheric CO2

Introduction This has led to an increased interest in the (return to? ) concept of climate variability as a possible reason for the “hiatus”. Climate has always changed?

Climate: Definition Climate  Is the long-term or time mean state of the earth- atmosphere system and the state variables along with higher order statistics. Also, we must describe extremes and recurrence frequencies. Climate Change  is any change in the long term statistics. Climate Variability  internal fluctuations that result from the interactions between parts of the climate system or within one subsection.

Climate The earth-atmosphere system, courtesy of Dr. Richard Rood. (http://aoss.engin.umich.edu/class/aoss605/lectures/)

El Niño and Southern Oscillation El Niño and Southern Oscillation / La Niña El Niño has a periodicity of two to seven years. (Philander, 1989) Defined as five straight months of the running six-month sea surface temperatures in the Pacific Ocean region < -0.5o C from the climatological mean.

El Niño and Southern Oscillation Maps / Data – January 2018

El Niño and Southern Oscillation El Niño history; Noted in South America by the indigenous peoples of the region and “coined” El Niño by the Spanish in the 1660’s. Sir Gilbert Walker and the Southern Oscillation in the 1920s

El Niño and Southern Oscillation J. Bjernes (1969) links SO to El Niño. El Niño of 1982-1983 makes news! (Images “stolen” from PMEL – NOAA.

El Niño and Southern Oscillation La Niña

El Niño and Southern Oscillation Impact on the USA is via the jet stream (El Niño: the 800 lb gorilla of short term variability)

Pacific Decadal Oscillationon Pacific Decadal Oscillation  Only Known since the late 1990’a starting with Minobe (1997) and Gershunov and Barnett (1998). PDO is a Pacific ocean basin-wide fluctuation (50 – 70 years) in SSTs.

Pacific Decadal Oscillation Maps: PDO+ Warm east Pacific / Cold West Pacific PDO+ PDO-

Pacific Decadal Oscillation PDO+ from 1977 – 1998, and 1924 – 1946. PDO- from 1947-1976, 1999 – present. Modulates El Niño (Berger et al. 2003; Lupo and Johnston 2000; Lupo et al. 2002; Kelsey et al, 2007, Lupo et al. 2008; Birk et al. 2010).  May be linked to global themohaline circulation and North Atlantic Oscillation.

Missouri Impacts The impact of El Niño on Missouri weather is very complex, but the impact of the PDO is to modulate the El Niño signal. During PDO-, the El Niño signal is weak over most of the state, the only exception in southern Missouri. Columbia, MO Temperatures -PDO La Niña Season Warm Months Cool Months Normal Months Winter 11.8% 3.9% 84.3% Spring 9.8% 78.4% Summer 5.9% 17.6% 76.5% Fall 13.7% 80.4%

Missouri Impacts La Niña winters – generally cold for Missouri with more snow, and decent precipitation. Southern part warmer and drier. El Niño – two types Weak – Like La Niña Strong – warm and dry winters with less snow, but southern Missouri is cooler and wetter with more snow.

Agricultural Impacts El Niño thought to have no impact on summer weather. New Research is showing that it is the transition between El Niño to La Niña that is correlated to summer weather, especially in Missouri. Newberry et al. (2016).

Agricultural Impacts The transition toward La Niña generally is associated with hot dry weather in the summer (1954, 1988, 2011, 2012). Transition to La Nina summers are 1-2o F warmer than other summers. Also drier The transition toward El Niño means generally favorable summer weather, cool and moist, but a dry spell late (2015).

Agricultural Impacts Temperature – crop production

Agricultural Impacts Precipitation – crop production

Climate Prediction Center Forecasts Spring 2018 Forecast (March – May)

Climate Prediction Center Forecasts Summer 2018 Forecast (June – August)

Model Projections December 2017 January 2018

Our Very Early Preliminary Forecast – Summer 2018 Temperatures within the range of normal or “typical for a summer season in Missouri. Possibly a hot spell in mid-late August. Basically good news for cooling bills. Normal to above normal amounts of precipitation, especially June and July. Reasoning: We are in a La Nina year now. Models project the Pacific moves into El Nino next year. This kind of transition is positive for agriculture.

Conclusions Climate change is expected to influence this region over the next century, models are probably over-stating the strength of the changes. Climate variability particularly the El Niño and Pacific Decadal Oscillation have a profound impact on our weather and climate in both winter and summer.

Conclusions Climate variability is perhaps the larger issue for agricultural interests. Economically, adaptation is the best strategy for climate change whether it is human or naturally forced. We have enough information now to project probable temperature and precipitation patterns for 4 – 12 months regularly and make reasonable generalized projections out one to two decades.

The End! Questions? Comments? Criticisms? lupoa@missouri.edu