Researchers from around the world are converging this week near the tiny island of Nauru in the Tropical Western Pacific where they'll launch a month-long atmospheric research effort to uncover clues regarding how the tropics influence weather and climate worldwide. The Tropical Western Pacific serves as the earth's heat engine, driving global weather events such as El Nino and La Nina, but this "furnace" is poorly understood.
From mid-June to mid-July, Nauru and its surrounding waters will host the most complete suite of atmospheric instrumentation ever installed in the Tropical Western Pacific. Included will be large research vessels, aircraft, buoys and research balloons, all equipped with specialized instrumentation to gather a variety of atmospheric data.
Nauru99 is sponsored by the Department of Energy's Atmospheric Radiation Measurement (ARM) Program and will be conducted in partnership with the National Oceanic and Atmospheric Agency (NOAA), the Japan Marine Science and Technology Center (JAMSTEC), Australia's Flinders University and several American universities.
Of particular interest to campaign participants is the energy flux, or transfer of energy, that occurs between the ocean and atmosphere. Scientists will study how radiative energy enters and exits the ocean surface, and how clouds affect this transfer.
"These energy fluxes are the primary means by which the ocean impacts our atmosphere," said Tom Ackerman, chief scientist for the ARM program. "A better understanding of these mechanisms will provide valuable insights into how the tropical ocean impacts weather and climate across the globe."
According to Ackerman, the bulk of information on ocean-atmosphere energy fluxes stems from relatively short-term ship and aircraft experiments. To supplement this, the ARM program launched an effort in 1997 to obtain long-term, land-based measurements through installation of major facilities on Manus Island in Papua New Guinea, and most recently on Nauru. These measurements focus on downwelling, or the downward direction, of radiative energy from the atmosphere and the effect of clouds on this energy.
Island-based measurements are cheaper and logistically easier to obtain than ship-based measurements and provide the only opportunity for multi-year observations. Scientists, however, must identify and adjust for the influence of the landmass on these measurements.
"Nauru99 is the first comprehensive experiment to determine whether land-based measurements serve as effective surrogates for ocean measurement and, therefore, how well these measurements can be used to develop more reliable climate models," said M.J. Post, chief scientist for the research vessel Ron Brown from NOAA's Environmental Technology Laboratory.
Beginning June 23, the campaign will focus on detailed comparisons of island- and ocean-based measurements. Configured in a triangle approximately 360 miles in circumference, the three primary data collection points will consist of NOAA?s Ron Brown research vessel, JAMSTEC's Mirai research vessel and ARM's instrumentation installation on Nauru. The configuration will enable scientists to simultaneously collect and compare data from both ships, the island and the more than 70 NOAA instrumentation buoys currently anchored throughout the tropical ocean.
The field portion of the campaign will conclude July 17. Initial data analyzed by individual scientists will be integrated to provide a clearer picture of ocean-atmosphere interaction and island effects. Final results of the campaign will be released early next year, although some preliminary results may be released this fall. Scientists expect data collected in Nauru99 to be used for scientific investigations over the next decade.
For more information on Nauru99, including photos, daily updates and a detailed
science plan, please see the Nauru99 web
site at:
http://www.arm.gov/docs/news/nauru99/