Published: 3 October 2011

Data spanning the Maldives to Papua New Guinea will help scientists analyze far-reaching tropical weather cycle

Like the lyrics in the song from the 1970s, the ARM Mobile Facility is going to stay in the Maldives “for a while, maybe longer”—about six months, actually—in support of the ARM Madden Julian Oscillation (MJO) Investigation Experiment, or AMIE. Starting October 1, the AMF began obtaining measurements from the sky above Gan Island, part of the Addu Atoll in the Maldives. This area of the southern Indian Ocean is where the MJO develops and starts moving eastward. Combined with continuous measurements from ARM’s permanent site on Manus Island in Papua New Guinea, data collected during AMIE will help scientists who want to analyze the atmospheric phenomena that drive the MJO and improve the way this information is used in climate models.

The MJO is a tropical weather system that occurs every one to three months or so, increasing large scale cloudiness and precipitation as it continues its eastward journey along the equator. AMIE and partner campaigns DYNAMO and CINDY2011 are focusing their efforts on the MJO because of its influence on regional weather patterns and far reaching effects on the global climate system.

About two dozen research organizations from both the United States and abroad are using ground-based, shipborne, and airborne instrumentation to obtain comprehensive measurements of the MJO. AMIE extends the study’s range to include Manus Island in Papua New Guinea, where the MJO strengthens again after weakening over the area around Indonesia and the Philippines known as the “maritime continent.”

“We’re throwing as much as we can at this effort and are confident we’ll have an incredible data set when the dust settles in six months,” said Dr. Charles Long, an atmospheric scientist at Pacific Northwest National Laboratory and principal investigator for AMIE. “This is the first time that a lot of ARM’s new Recovery Act instruments are being used in a tropical field campaign, and we’re eager to start looking at the new data.”

Brad Orr and Mike Ritsche, AMF site manager and technical operations manager, respectively, from Argonne National Laboratory, are overseeing the AMF operations on Gan at two locations. Most of the instruments are located at the Gan airport, where local assistants have been trained to help launch weather balloons—eight per day—for the duration of the project. The new X-band and Ka-band scanning radars will be stationed at a wharf site to the north.

On October 10, an opening ceremony at the AMF airport site will kick off the DYNAMO and AMIE campaigns with presentations and tours for government officials, invited guests, and media. The event will also allow the researchers to recognize their local host—the Maldivian Meteorological Service—for their important contribution to these extended efforts.

For more information, follow the AMIE blog or refer to the following press releases and websites:

Climate scientists study equatorial storms between Indian and Pacific Oceans, Pacific Northwest National Laboratory

Scientists Probe Indian Ocean for clues to Worldwide Weather Patterns, National Science Foundation and National Center for Atmospheric Research

• AMIE – ARM Madden Julian Oscillation Investigation Experiment
• DYNAMO – Dynamics of the Madden Julian Oscillation
• CINDY2011 – Cooperative Indian Ocean Experiment on Intraseasonal Variability in the Year 2011