Meet Mr. Madden, Mr. Julian and Their Oscillation

This year’s Climate and Society class is out in the field (or lab or office) completing a summer internship or thesis. They’ll be documenting their experiences one blog post at a time. Read on to see what they’re up to.

Yiting (Will) Chen, C+S ’17

Super Typhoon Noru turned into a Category 5 storm in late July, the strongest so far in 2017 in the northern hemisphere. Noru’s approach to central Japan prompted evacuation advisories for tens of thousands of people, and more than 400 flights were canceled. In the past few days, tropical cyclone activity increased markedly as tropical storms Kulap and Sonca also formed near East Asia, pounding Southeast Asia with more than a month’s worth of rain. The related flooding has caused more than $3 million and killed 23 across Thailand.

Better forecasts have the potential to save lives. These storms and cyclones didn’t come out of nowhere. They emerged in part because of an atmospheric pattern, the Madden-Julian Oscillation (MJO), which was discovered by Roland Madden and Paul Julian in the early 1970s. The MJO is about more than typhoons in the Pacific. It can also modulate the timing and strength of monsoons in India, influence tropical cyclone numbers and strength in nearly all ocean basins, and drive cold air outbreaks, heat waves and flooding rains over North America. Despite all these impacts, the average person has probably never heard of the MJO. I am working on a project this summer to change that, which could help the general public better understand the climate pattern.

Unlike the more well-known El Niño-Southern Oscillation which forms and stays in the Pacific region, the MJO is a travelling pattern that propagates eastward from the Indian Ocean to the Central Pacific. The pattern typically recurs every 30-60 days. Imagine the MJO as a person riding a bike on a stage. He/she enters the stage on the left and slowly exits to the right. The changing location of the rider is associated with the changes of rainfall and winds that are linked to the MJO. This bike rider may cross the stage from left to right several times during the show.

The MJO consists of two phases: a convective phase with enhanced rainfall and a suppressed rainfall phase. Usually the two phases separate the globe in half.

During the enhanced convective phases of the MJO, heavy precipitation can become the most devastating weather phenomena, as it is frequently accompanied by hazardous events such as lightning, hail, heavy snow, and strong surface winds. The MJO was active in the 2004–05 winter over most of the Western and Midwestern U.S. A large region received up to 400 percent more precipitation than average and four major storms hit the country with heavy precipitation and snow. The impact of the storms was widespread, causing tens of millions of dollars in damage and killing more than 20.

When it comes to the suppressed convective phase of the MJO, the impacts are quite the opposite. Due to the coupled effects of El Niño and the MJO, the drought of 2012 in Northeast Brazil became one of the worst in the past 40 years, and caused the loss of more than 80% of bean and corn crops, according to the National Food Supply Agency. A total of 880,000 farmers received federal assistance from social support programs after accumulating huge debts. Other problems included migration, disease, and malnutrition. The aftermaths of the disaster still haunting the region, hampering local economic and social developments.

The complexity of analyzing MJO phases and its variability make it rather difficult for people with no prior knowledge in climate and atmospheric science to understand its movements and effects. This is why I started my internship at the International Research Institute for Climate and Society (IRI). My supervisor and I decided to produce a maproom — a digital climate resource on IRI’s website — that will help people understand and even utilize the knowledge of the impacts and prediction to better prepare for disasters and even improve local forecasts. The maproom will present the viewers with brief introductions of the MJO and its phases and impacts. More importantly, it will display anomaly values of forecast temperature (figure 1), precipitation and sea level pressure to help the average person understand the actual impacts of the MJO. The final product will be posted on the IRI website as a free and open-source tool for anyone that would like to learn about the climate pattern.

An example of the components of the maproom showing ensemble-mean weekly averages for temperature 2-meter above the ground based on the ECMWF model for the period between Jan 2016 and Jul 2017 (Source: Will Yiting Chen)

When I told my friends about my work at IRI, some of them were quite suspicious, questioning me how much of an impact this project can make to the general public.

“Even if this maproom is designed specifically to help ordinary people understand the impacts of MJO, simply knowing the changes in rainfall and temperature would not make much of a difference to them,” one said to me.

In a sense, that is true. A few graphs and numbers could mean very little, even when explained thoroughly. But what matters the most is not about how much in-depth knowledge people can learn from our maproom, but about providing them with the opportunity to come in contact with such information in an accessible manner.

It is crucial for the general public to understand that climate science is not a distant and mysterious subject, but something that directly impacts their lives. I am grateful for the opportunity at IRI, not because it fulfills my internship requirement, but because I am able to engage in a job that can actually help promote climate awareness and interests and hopefully make a difference.

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