Individual raw data streams from instrumentation at the Atmospheric Radiation Measurement (ARM) Program Climate Research Facility (ACRF) fixed and mobile sites are collected and sent to the Data Management Facility (DMF) at Pacific Northwest National Laboratory (PNNL) for processing in near real-time. Raw and processed data are then sent daily to the ACRF Archive, where they are made available to users. For each instrument, we calculate the ratio of the actual number of data records received daily at the Archive to the expected number of data records. The results are tabulated by (1) individual data stream, site, and month for the current year and (2) site and fiscal year (FY) dating back to 1998. Table 1 shows the accumulated maximum operation time (planned uptime), actual hours of operation, and variance (unplanned downtime) for the period July 1 - September 30, 2008, for the fixed sites. The AMF has been deployed to China, but the data have not yet been released. The fourth quarter comprises a total of 2,208 hours. The average exceeded our goal this quarter. The Site Access Request System is a web-based database used to track visitors to the fixed and mobile sites, all of which have facilities that can be visited. The NSA locale has the Barrow and Atqasuk sites. The SGP site has a central facility, 23 extended facilities, 4 boundary facilities, and 3 intermediate facilities. The TWP locale has the Manus, Nauru, and Darwin sites. HFE represents the AMF statistics for the Shouxian, China, deployment in 2008. FKB represents the AMF statistics for the Haselbach, Germany, past deployment in 2007. NIM represents the AMF statistics for the Niamey, Niger, Africa, past deployment in 2006. PYE represents just the AMF Archive statistics for the Point Reyes, California, past deployment in 2005. In addition, users who do not want to wait for data to be provided through the ACRF Archive can request a research account on the local site data system. The seven computers for the research accounts are located at the Barrow and Atqasuk sites; the SGP central facility; the TWP Manus, Nauru, and Darwin sites; and the DMF at PNNL. In addition, the ACRF serves as a data repository for a long-term Arctic atmospheric observatory in Eureka, Canada (80 degrees 05 minutes N, 86 degrees 43 minutes W) as part of the multiagency Study of Environmental Arctic Change (SEARCH) Program. NOAA began providing instruments for the site in 2005, and currently cloud radar data are available. The intent of the site is to monitor the important components of the Arctic atmosphere, including clouds, aerosols, atmospheric radiation, and local-scale atmospheric dynamics. Because of the similarity of ACRF NSA data streams and the important synergy that can be formed between a network of Arctic atmospheric observations, much of the SEARCH observatory data are archived in the ARM archive. Instruments will be added to the site over time. For more information, please visit http://www.db.arm.gov/data. The designation for the archived Eureka data is YEU and is now included in the ACRF user metrics. This quarterly report provides the cumulative numbers of visitors and user accounts by site for the period October 1, 2007 - September 30, 2008. Table 2 shows the summary of cumulative users for the period October 1, 2007 - September 30, 2008. For the fourth quarter of FY 2008, the overall number of users is down substantially (about 30%) from last quarter. Most of this decrease resulted from a reduction in the ACRF Infrastructure users (e.g., site visits, research accounts, on-site device accounts, etc.) associated with the AMF China deployment. While users had easy access to the previous AMF deployment in Germany that resulted in all-time high user statistics, physical and remote access to on-site accounts are extremely limited for the AMF deployment in China. Furthermore, AMF data have not yet been released from China to the Data Management Facility for processing, which affects Archive user statistics. However, Archive users are only down about 10% from last quarter. Another reason for the apparent reduction in Archive users is that data from the Indirect and Semi-Direct Aerosol Campaign (ISDAC), a major field campaign conducted on the North Slope of Alaska, are not yet available to users. For reporting purposes, the three ACRF sites and the AMF operate 24 hours per day, 7 days per week, and 52 weeks per year. Time is reported in days instead of hours. If any lost work time is incurred by any employee, it is counted as a workday loss. Table 3 reports the consecutive days since the last recordable or reportable injury or incident causing damage to property, equipment, or vehicle for the period July 1 - September 30, 2008. There were no incidents this reporting period.