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by Bob Henson

Data being gathered by several radars across the Sahel in support of weather modification may be used in other ways, as proposals for regional data sharing proceed. (Photo courtesy Roelof Bruintjes.)

At a 2005 meeting of the UCAR Board of Trustees in Boulder, Shirley Malcom was paying close attention to Richard Anthes as the UCAR president described the organization’s international reach. In front of the trustees was a map with dots speckling the countries where NCAR and UOP maintain collaborations, carry out research, or provide support services. Most continents had at least a few dots—except for Africa.

“This was only a couple of months after Hurricane Katrina,” says UCAR trustee Malcom, who oversees education and human resources at the American Association for the Advancement of Science (AAAS). “I said, ‘Wait a minute. How can we say that we’re studying global climate systems when there’s so little UCAR presence in Africa?’” As Malcom points out, many of the hurricanes that strike the U.S. Gulf and Atlantic coasts begin as clusters of thunderstorms crossing the African Sahel. But Malcom was thinking about more than hurricanes. Her larger point was that UCAR sorely lacked research, facility, and educational links to an important part of the globe.

That’s beginning to change, though. Malcom’s query at the 2005 board meeting served as the catalyst for the UCAR-AAAS Africa Initiative, which encompasses a wide range of activities. These include an adaptation of the Weather Research and Forecasting model (WRF), an upgrade of several radars, and an expansion of school-based observing through the GLOBE Program.

An initiative is born

After Malcom’s remarks at the board meeting, “nobody got defensive,” she recalls. Instead, “Rick Anthes began a conversation about how we might break into this area.” The committee that resulted chose to leverage and coordinate projects that already exist instead of trying to launch entirely new efforts. Its guiding principle is to integrate research and education while building the capacity for locally based research, with African rather than American institutions setting the agenda.

Anthes tapped Raj Pandya to coordinate the fledgling initiative. Since 2004 Pandya has managed the Significant Opportunities in Atmospheric Research and Science program (SOARS), which provides support and mentorship for students working toward doctoral degrees in atmospheric and related sciences.

Because many SOARS protégés are from underrepresented groups, Pandya is familiar with bridging technological and sociological divides and forging new communities. In this case, he uncovered a community that wasn’t aware of its own existence. “We found there was already a surprisingly large amount of NCAR and UOP activity involving Africa,” says Pandya, “but only a few of the participants were aware of each other’s activities.”

Much of the activity thus far has centered on the Sahel, where the contrast between the moist Guinea coast and the bone-dry Sahara leads to some of Africa’s most extreme weather and some of the worst environmental stresses on vulnerable societies. Hoping to produce more climatic consistency, several nations in the region have sponsored cloud-seeding efforts over the last few years, with aircraft and radars acquired for that purpose. One of the largest players in Sahelian weather modification is Burkina Faso’s Project SAAGA, which maintains a King Air turboprop and two C-band weather radars.

Those two radars, plus a third in Mali, can now measure winds as well as precipitation thanks to low-cost, easy-to-use digital processors installed in 2006 through a subcontract with NCAR. The upgrades were completed in time for the African Monsoon Multidisciplinary Analyses (AMMA), a large international study of wet-season weather and climate across the Sahel and nearby areas. Although the radars aren’t officially part of AMMA, NCAR’s Roelof Bruintjes and colleagues are working to help make the radar data available to the project’s scientists, in part by applying distribution strategies in Burkina Faso that were developed by UOP’s Unidata program to help American universities acquire and analyze real-time weather data.

Bruintjes is also collaborating with the governments of Burkina Faso and Mali to analyze the results of the rainmaking projects they sponsor. He’s ­carried out similar studies in a number of other venues, including Mexico, Wyoming, the United Arab Emirates, and South Africa. In the Sahel, he says, ­weather modification is a political hot potato: it’s supported by national governments but unpopular among some researchers and forecasters. “We’re ­trying to encourage a rigorous scientific approach and wider use of the observing infrastructure, while simultaneously being sensitive to the political decision-making process,” says Bruintjes.

In this case and others, initiative leaders are working closely with African scientists to learn more about their research interests and operational needs, rather than providing resources that may not be required or desired. “We know we have to understand the priorities from the African point of view,” says Pandya. For example, the formation of tropical cyclones isn’t a particularly hot topic for Africans themselves, since the related impacts occur on the other side of the Atlantic. However, rainfall variations are of keen interest, especially in the Sahel.

Benjamin Lamptey, an NCAR postdoctoral researcher born and raised in Ghana, is collaborating with NCAR’s Tom Warner and

colleagues on adapting the WRF model to provide the most detailed picture yet of day-to-day weather in West Africa, particularly around Ghana. “The onset and cessation of the rains is the main forecast challenge. People want to know when there will be a dry spell or wet spell, even during the rainy season,” says Lamptey. Also important are dust storms produced by the harmattan, a dry northeasterly wind that often develops in winter. “The harmattan has implications not only for air quality and health but also for aviation,” he says.

Lamptey completed his doctorate at The Pennyslvania State University before joining NCAR’s Advanced Study Program in 2005, just as the Africa Initiative was getting under way. Right off the bat, he mentioned to colleagues his dream of a top-notch operational model for West Africa, “but that was just a postdoc talking,” he says. Later that year, Lamptey gave a presentation to UCAR’s initiative leaders and mentioned his dream again. This time he found that support was indeed available for the project from a pool of seed money ­allocated for the Africa Initiative over the last two years by Anthes and NCAR director Tim Killeen.

The real-time African WRF model debuted on the Internet last fall. Before then, the best operational models for sub-Saharan Africa featured top resolutions of around 13.5 kilometers. WRF can match that resolution for West Africa and zoom in to a grid as fine as 4.5 km in the vicinity of Ghana. This spring Lamptey and colleagues installed a set of dedicated computers in Boulder to keep the model running 24/7. “We want input from forecasters in Africa,” says Lamptey. “For example, they can tell us if the sea breeze is being forecast too deeply by the model.”

Once Lamptey completes his two-year postdoctoral stint in NCAR’s Advanced Study Program, he plans to return to Africa and the Ghana Meteorological Agency in Accra, where he worked before entering graduate school. Lamptey also plans to work with professors in Ghana to help establish a full-fledged program in atmospheric science. He connected with several of his African peers this spring while attending The Sahel Conference 2007: Improving Lives by Understanding Weather. More than 80 participants from 18 nations convened in the Burkina Faso capital of Ouagadougou during the first week of April.

Aimed at increasing the value and use of local weather data and models, the conference was cosponsored by Programme SAAGA, the weather services of Mali and Burkina Faso, and UCAR. The weather itself bore out the meeting’s theme of atmospheric impacts, says Lamptey. His flight from Accra was delayed by a strong harmattan outburst in Ouagadougou; then an unusual squall line for the time of year blew through during the conference, bringing light rain and more wind.

The four working groups at the Sahel meeting identified a variety of desirable steps, including a memorandum of understanding toward free and open exchange of radar data in the Sahel and neighboring nations;

• an expanded network of radars across West Africa, with subregional data centers as Internet capacity allows;


• strengthening the capability for predicting dust storms;


• partnerships and regional strategies for carrying out and analyzing weather modification efforts; and


• a staged approach to improving numerical weather prediction, with universities and forecast centers collaborating within each nation and then building international links.

Instruments and students

The Sahel Conference also led to a new node in the worldwide network of school-based observing sites created through the UOP-based GLOBE Program. This new weather station is one of about 600 GLOBE observing sites in 23 African nations. It was installed at the Lycee Nelson Mandela High School with help from the school’s director, Jean Pierre Korsaga; NCAR’s Paul Kucera; and Ngosse Fall, the GLOBE coordinator for Senegal, who conducted onsite training on how to take weather observations. “The teachers and students were very excited to be involved in the program,” says Kucera. He adds that several conference-goers from nearby nations expressed interest in establishing their own GLOBE sites.

Also at the conference was Sherri Heck, a graduate student at the University of Colorado, who wants to place a different kind of instrument in Africa. For her doctorate, Heck is analyzing regional fluxes of carbon dioxide. She’s using the topic as a springboard to bring science research and education into under-served areas. By working with local schools, Heck hopes to entrain students while gathering data that could prove vital to climate research. “If you go in and take data from a region, I think you should give something back,” she says.

Heck is applying this philosophy in the United States as well as Africa. She’s collaborating with Marnie Carroll (Diné College) to place a CO2 monitoring device atop Roof Butte on Navajo land in northeast Arizona. Navajo students at Diné will learn how to operate and maintain the instrument and will have a chance to create their own CO2-related research project. The instrument, dubbed the Autonomous Inexpensive Robust CO2 Analyzer (AIRCOA), was developed by NCAR’s Britt Stephens and colleagues. Components for each AIRCOA unit cost less than $10,000. The device gathers and relays CO2 readings every 2.5 minutes, and it can be run autonomously for months at a time. It will fill a key niche in Arizona, says Heck: “The southwest United States is poorly represented in terms of carbon dioxide measurements.”

Scientists also have much to learn about regional CO2 fluxes in Africa. Heck proposes to site one of the AIRCOA units on an African mountaintop as part of the Afriflux CO2 monitoring network. “One of the weakest links in our current understanding of the global carbon cycle is in Africa, mostly due to a lack of data,” says Heck. At the Sahel meeting, she met several African scientists who are eager to help her find a suitable location for AIRCOA. She’ll also need to find one or more collaborators and a local school to work with, as well as funding for the instrument itself.

“I’ve struggled almost my whole life to combine my love of science with my love of helping people,” says Heck. “This is my attempt to marry the two.”

	UCAR-AAAS Africa Initiative 4DWX West Africa Demonstration Project (WRF model) The Sahel Conference