Operations Updates
ARM Climate Research Facility Operations Update - April 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).
Infrared Thermometers Complete Cloud Pictures
Extended Facilities at the SGP are spaced far enough apart that they do not have overlapping views overhead. This separation allows the infrared thermometers to obtain specific measurements for individual cloud cases. (Click map for a larger version.)
To help ARM scientists analyze cloud temperatures and infer cloud heights over the ACRF Southern Great Plains (SGP) site, operations staff are installing six new infrared thermometers (IRTs) at Extended Facilities throughout the domain, with plans to eventually equip all Extended Facilities. One of the primary uses of these data is to test and combine with satellite data. While satellite data affords good spatial coverage across the area, it only provides a "snapshot" every half hour, and has known weaknesses, especially in inferring such quantities as low cloud base heights, low cloud amounts, and detection of few or smaller clouds. Having the additional IRT retrieval points for comparison and testing will allow the ARM science team to refine the retrievals by cloud situation.
A filtered fan keeps moisture from building up on the mirror surface (bottom left) by circulating air up through the optical port (top left) of the IRT enclosure.
New features for the IRT include a mirror surface hardened with a thin coating of silicone dioxide, and a prototype automatic mirror washing/drying system to keep the IRT mirror surfaces clean and free of dew or frost, thereby providing more accurate measurements of sky brightness temperature. To evaluate the cleaning system and study the freezing characteristics of the cleaning fluid, sample systems were tested during the winter months on the elevated instrument platform of the SGP Guest Instrument Facility. In addition, a new data acquisition and display system developed by ARM personnel is capable of logging the IRT serial data at a minimum of 5Hz. This system was tested for compatibility with the Linux© computers like those at the SGP Extended Facilities, as well as with the Windows© operating systems planned for installation at the ACRF Tropical Western Pacific and North Slope of Alaska locales.
Members of the ARM science team will take the satellite "snapshots" and compare to the IRT cloud retrievals, then use the satellite data to help interpolate and analyze the SGP domain. By using surface and satellite data, ARM researchers can "paint a more complete picture" of both temporal and spatial resolution. One application of these data is in support of the Broadband Heating Rate Profile (BBHRP) project, a comprehensive effort by the ARM science team to provide a critical tool for evaluation of radiation measurements, radiative transfer models, and the specification of the relevant atmospheric properties, with a key focus on clouds. The spatial variability of clouds across the SGP site must be included for the BBHRP to provide a realistic estimate of heating rates for the SGP area as simulated by single column models.
User Facility Improvements Continue at North Slope of Alaska Locale
The "skydeck" at Barrow shows how the instrument platforms can get very crowded during peak experimental periods.
Two things are critical for conducting scientific research: adequate equipment and power. This is especially true in the Arctic, where average winter temperatures hover around -30 degrees Celsius, and access to additional resources is limited. After experiencing crowded working conditions during complex field campaigns last year, followed by several power outages this past winter, operations staff at ACRF's North Slope of Alaska (NSA) locale began implementing measures to improve the situation. Part of the solution is contained in a new emergency response plan, which addresses various emergency conditions. The other part is focused on upgrading various infrastructure capabilities.
Power outages at the NSA Barrow site this past winter spurred an investigation into potential upgrades for the power line serving the NSA Barrow site, which also feeds power to equipment used by National Oceanic and Atmospheric Administration (NOAA), U.S. Geological Survey, and nearby National Science Foundation projects. Operations staff discovered that not only is the current power feed several decades old, but it also makes use of obsolete equipment for which replacements are not readily available. They also found the feed is being operated closer and closer to maximum capacity. To better prepare for future power outages and other mishaps, the site operations manager procured a snowblower and backup generator, and prepared an emergency response plan that summarizes response actions in the event of power failures, fires, floods, and medical emergencies. In the longer term, the plan involves replacing the power line to the "Great White" instrument shelter at Barrow and the nearby facility operated by NOAA. Discussions are underway with the affected organizations to see if an agreeable arrangement can be made to share the costs of the needed modernization and capacity upgrade.
From a logistical standpoint, a number of steps are being taken to handle additional users and instruments, and alleviate overcrowding. Design modifications to the existing instrument platform in Barrow were completed in fall 2004 to accommodate two new insulated shelters for housing additional data systems. The shelters, built to withstand tropical heat, demonstrated their utility in cold weather during the Mixed-Phase Arctic Cloud Experiment, and are scheduled to arrive in Barrow this summer. A laboratory area within the site maintenance building is also under development to provide even more room for researchers and their equipment. And lastly, operations staff eagerly anticipate the arrival of a new four-wheel drive crew-cab flatbed pickup this summer, as well as the possibility of access to a light-duty pickup through an agreement with the Barrow Arctic Science Consortium.
