LIVERMORE, Calif. -- Summertime in northern Australia means monsoonstorms -- and plenty of them. Tall, turbulent clouds associated withthese storm systems form rapidly, release their energy in the form ofrain, then tail away, leaving in their wake a surplus of moisture tofeed the next system. This lifecycle--the formation of tropicalconvective clouds, their outflow into cirrus clouds, and eventualdissipation into water vapor--is a key component of tropical climate.However, the cloud properties and the extent of their impact on theenvironment are not well understood or well represented in computermodels that are used to simulate climate change.
This week, a team of more than 25 international cloud climatescientists are conducting a three-day operations and planningsimulation at Sandia National Laboratories in Livermore, California, toprepare for a complex experiment that will result in the most detaileddata sets ever collected for tropical convection. Led by scientistsfrom the U.S. Department of Energy's Atmospheric Radiation Measurement(ARM) Program and the Australian Bureau of Meteorology (BOM), theTropical Warm Pool International Cloud Experiment will take place inthe region around Darwin, Australia, between January and February 2006.
Darwin is home to one of the ARM Program's permanent research sites,equipped with a sophisticated array of remote sensing instruments tocollect the continuous measurements needed to improve computer modelsthat simulate clouds and climate. The upcoming experiment will includean unprecedented network of ground-based instrumentation, a shipoperating off the coast near Darwin, and a fleet of low-, middle- andhigh-altitude aircraft for in-situ and remote-sensing measurements.Aircraft measurements taken during the experiment will be valuable forvalidating and improving existing ground-based measurements from theARM site in Darwin, as well as satellite observations obtained by theNational Aeronautics and Space Administration (NASA).
The operational complexity, not to mention the monsoon environment,makes the experiment a challenging undertaking, to say the least.
"After more than two years of planning for this experiment, we arenearing the operations phase," said Jim Mather, ARM's lead scientistfor the experiment. The most challenging aspect of our operations willbe coordinating multiple research aircraft during the complex monsoonseason. Because our time in the field is so limited, this simulationexercise allows us to examine all aspects of the critical flightcoordination process."
Each day of the simulation will involve weather briefings and missionplanning to reflect actual field operations and flight scenarios duringthe experiment. The team is conducting a debriefing and critique at theend of each day to discuss any issues and identify needed changes totheir planned situation analysis, decision processes, communicationsprotocols, and procedure development.
In addition to the ARM Program and BOM, other key participants in theexperiment include the ARM Unmanned Aerospace Vehicle (ARM-UAV)Program, the Australian Commonwealth Scientific and Industrial ResearchOrganization, NASA, and Airborne Research Australia. In addition,scientists from several universities in the United States, Australia,Canada, Japan, and the United Kingdom are participating in theexperiment. Both the Royal Australian Air Force and the Regional BOMOffice will host the aircraft operations and be heavily involved inforecasting efforts.
"This is truly an international collaboration focused on climate changeresearch," said Wanda Ferrell, ARM Program Manager for the Departmentof Energy's Office of Science. "When we agreed to fund the experiment,we were hopeful it would gain wide support. The number of collaboratorshas exceeded expectations, and the scientific commitment to theexperiment is impressive. We are very optimistic about the progressmade thus far, and are already looking forward to the results."
ARM scientists will use data from the experiment to improve computermodels that simulate tropical climate by examining convective cloudsystems from their initial stages through to the decay of the cirrusgenerated, and to measure their impact on the environment. Otherscientific collaborators in the experiment will focus on measuring avariety of active chemical species transported by convection into theupper troposphere and lower stratosphere. These measurements willprovide important information about the interaction of the troposphereand stratosphere and about chemical processes associated with ozoneproduction and destruction.
The ARM Program is funded through the U.S. Department of Energy's Office of Science.
Additional information about ARM Program science and the ARM Climate Research Facility is available at www.arm.gov.
Sandia is a multiprogram laboratory operated by Sandia Corporation, aLockheed Martin company, for the U.S. Department of Energy's NationalNuclear Security Administration. With main facilities in Albuquerque,N.M., and Livermore, Calif., Sandia has major R&D responsibilitiesin national security, energy and environmental technologies, andeconomic competitiveness.
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