Operations Updates
ARM Climate Research Facility Operations Update - June 15, 2005
This bimonthly report provides a brief summary of significant accomplishments and activities in the operations area of the ARM Climate Research Facility (ACRF).
Guest Instruments to Collect Aerosol Data During Coastal Field Campaign
The counter-flow virtual impactor (inset), which can characterize aerosol particles in cloud droplets, joins a number of other guest instruments at the ARM Mobile Facility deployment site at Point Reyes National Seashore in California.
The ARM Mobile Facility's (AMF's) inaugural field campaign, the Marine Stratus Radiation Aerosol and Drizzle (MASRAD) Intensive Operational Period, is well underway at Point Reyes National Seashore on the northern coast of California. As the title implies, the goal of MASRAD is to study the characteristics of marine stratus clouds, particularly the influence of aerosol particles on marine stratus drizzle properties. Taking advantage of the location and infrastructure established to support the campaign, a number of guest instruments are joining the AMF deployment to aid in the collection of data on aerosol properties.
The Cadenza cavity ring down instrument, provided by the National Aeronautics and Space Administration's Ames Research Center, is being deployed from June through August to measure aerosol optical properties. "Cavity ring down" refers to the method of bouncing a pulse of light back and forth inside an enclosed cavity to measure the rate of extinction-or "ring down"-of the particles over time. The Cadenza technique uses this method plus independent measurements of light scattering on the same sample to obtain light absorption and albedo values. Measurements taken by the Cadenza will be compared with measurements taken by a Particle Soot/Absorption Photometer and other photoacoustic instruments included in the AMF baseline instrument collection. These measurements will provide a better understanding of aerosol properties during cloud-free conditions.
To aid in observation of cloud-aerosol interaction, a counter-flow virtual impactor (CVI) will be implemented in July to sample cloud drops. The CVI, sponsored by researchers from the DOE Atmospheric Science Program, uses its counter-flow capability to draw large cloud drops into a system that evaporates the moisture, isolating the aerosols that form cloud condensation nuclei.
These guest instruments are just a few that have been added to or will soon join the AMF on location at Point Reyes. The MASRAD field campaign began in mid-March and will last until September. To learn more about this campaign, see the October-December 2004 News Archive.
New Total Sky Imager Improves Reliability Picture in Tropics
Data from the TSI measurements are presented as individual images and retrievals, including daily "movies" of sky conditions above the site.
Environmental conditions in the tropics present unique challenges for conducting scientific research. At the ACRF's Tropical Western Pacific (TWP) locale, instruments that collect climate data are continually subjected to adverse operating conditions that can impact their reliability. As part of an ongoing effort to add and upgrade instruments to meet these challenges, total sky imagers (TSI) were recently redesigned to improve their reliability at remote sites like those at the TWP. In May, a newly redesigned TSI was installed for the first time at the TWP Manus site in Papua New Guinea.
The TSI measures the horizontal distributions of clouds in its field of view, providing real-time processing and display in a visual record of daytime sky conditions. The instrument's software computes both the fractional cloud cover and sunshine duration, which are useful for interpreting other ARM measurements and important elements in understanding climate change. The TSI design modifications - including remote operating and troubleshooting capability, and streamlined internal electronics - will reduce the potential for system failure and resulting downtime, while also making it easier to maintain and repair.
The new TSI at Manus provides additional measurement capability to the suite of instruments already at that site. With similar instruments installed at Darwin, Australia, in January, and at Nauru Island in February, all the TWP sites now have the new TSIs. Completion of this effort greatly improves ACRF's routine data collection capabilities in the tropics.
Cloud Animation Joins Learning Tools on Science Education Website
ACRF's tropical convective clouds animation illustrates the difference between tropical cloud systems that form over islands versus over the ocean.
A primary focus of ACRF Education and Outreach is to develop basic science awareness and increase critical thinking skills focusing on environmental science and climate change for K-12 students. Though their efforts primarily focus on the communities that host ACRF sites, the program also supports relationship building between teachers, students, scientists, and other programs that seek to promote science education. At the request of WGBH-a public broadcasting company and National Public Radio affiliate-ACRF recently supplied a copy of its convective clouds animation for the Teachers' Domain© website.
The WGBH Educational Programming Department maintains the Teachers' Domain website, which provides teachers with useful lesson plans that include background information, a video/animation, and an activity for almost every lesson on their web page. Free and available worldwide, the website is gaining popularity among educators, who can make immediate use of the materials. The convective clouds animation will be added to the new Earth and Space Sciences section of the website, which is under development. Taking its place alongside Nova and other PBS video clips and animations already on the site, ACRF joins an impressive inventory in the Teachers' Domain science education toolbox.
