Bernard Daniel Zak

Initial results from the 2004 North Slope of Alaska Arctic winter radiometric experiment

A multiinstrument radiometric experiment was conducted on the North Slope of Alaska near Barrow, Alaska, during March 9 to April 9 2004. Initial radiometric and radiosonde data from this experiment are presented.

PREDICTING ATMOSPHERIC DEBRIS TRANSPORT IN REAL-TIME USING A TRAJECTORY FORECAST MODEL

Abstract An experiment is described in which a trajectory forecast model was used in real-time to estimate the transport of debris associated with a large chemical explosion in the south-western U.S. The forecast trajectories were used to vector sampling aircraft into a position favorable for intersecting the debris cloud. The forecasts are evaluated and compared with three independent measures of debris transport: diagnostic trajectories calculated after the experiment using observed wind fields; transport of a tracer balloon; and aircraft measurements of the debris cloud. Trajectory forecasts originating as early as 39 h before the explosion successfully predicted the downwind atmospheric drift pathway of the cloud. The forecast trajectories agreed well with diagnostic trajectories, confirming the high quality of the meteorological forecast data upon which the trajectories are based. The forecast trajectories also proved skilful in predicting real-rime atmospheric motion at short notice. The results support our conclusion that forecast trajectory models are valuable tools for vectoring sampling aircraft in long-range atmospheric dispersion experiments and operations. These models should prove useful in the future when real-time estimates of atmospheric transport are needed.

The Atmospheric Radiation Measurements (ARM) program: ARM's window on the Arctic

A ‘blue ribbon’ committee established by the U.S. National Academy of Sciences has stated that uncertainties associated with cloud behavior constitute the major obstacle to progress in climate modeling and prediction. The Atmospheric Radiation Measurements (ARM) Program is a 10-year climate research program aimed at unravelling the role of clouds in the climate system. The focus is on studying the life cycle of clouds and the effects of clouds on high-latitude ARM site. Global climate models appear to be particularly sensitive to climate perturbations at high latitudes. Of course, climate changes have profound effects on the ecology. One objective is to design a research program that will enable us to investigate the relationship between arctic clouds and anthropogenic pollution transported to the north from lower latitudes. The Arctic is also characterized by extreme seasonal variation in insolation, surface properties, and exchange of water vapor between the surface and the atmosphere. This extreme variation leads to important climate feedback mechanisms involving the interaction between surface temperature and water vapor, cloud cover, and surface albedo. The challenge for the Alaskan ARM site is to capture these high-latitude feedback processes for inclusion in global climate models. To put possible climate changes into perspective, we note that the ‘Little Ice Age’, which ended the pre-Columbian Icelandic colony in Greenland and probably prevented permanent settlements in Vinland (i.e. North America), represented an average decrease of only about 2–3°C.

Measurement and analysis of sound levels from a RASS site near Barrow, Alaska

Abstract Measurements of sound levels from an acoustic source for a RASS (Radio Acoustic Sounding System) system have been analyzed in support of the environmental assessment and permitting for an ARM (Atmospheric Radiation Measurement) site near Barrow, Alaska. Background sound levels and noise levels at two frequencies have been measured as a function of distance from the source. The Fast Field Program (FFP) is used to extrapolate the data for cases where the sound levels are significant at the maximum measurement range. The FFP is also used to investigate the effect of wind direction for three of the highest level days.

The U.S. Department of Energy's Atmospheric Radiation Measurement Climate Research Facilities on the North Slope of Alaska

The U.S. Department of Energy (DOE) provides scientific infrastructure and data archives to the international Arctic research community through a national user facility, the ARM Climate Research Facilities (ACRF), located on the North Slope of Alaska. ACRFs role is to provide infrastructure support for climate research, including Arctic research, to the global scientific community. DOEs climate research programs, with a focus on clouds and aerosols and their impact on the radiative budget, define the research scope supported by the Facility. This paper discusses the scientific infrastructure, data streams and archives, planned field campaigns, and opportunities for future collaborative research on the North Slope of Alaska.

Preliminary systems engineering evaluations for the National Ecological Observatory Network.

The National Ecological Observatory Network (NEON) is an ambitious National Science Foundation sponsored project intended to accumulate and disseminate ecologically informative sensor data from sites among 20 distinct biomes found within the United States and Puerto Rico over a period of at least 30 years. These data are expected to provide valuable insights into the ecological impacts of climate change, land-use change, and invasive species in these various biomes, and thereby provide a scientific foundation for the decisions of future national, regional, and local policy makers. NEONs objectives are of substantial national and international importance, yet they must be achieved with limited resources. Sandia National Laboratories was therefore contracted to examine four areas of significant systems engineering concern; specifically, alternatives to commercial electrical utility power for remote operations, approaches to data acquisition and local data handling, protocols for secure long-distance data transmission, and processes and procedures for the introduction of new instruments and continuous improvement of the sensor network. The results of these preliminary systems engineering evaluations are presented, with a series of recommendations intended to optimize the efficiency and probability of long-term success for the NEON enterprise.