An initiative is underway to establish the Argonne Boundary Layer Experiments (ABLE) facility to provide continuous, long-term observations of the planetary boundary layer (PBL) with state-of-the-art instruments. Planning for ABLE began during 1995, and implementation is expected to be mostly complete by 1998. ABLE will be located within the area now occupied by the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site of DOE`s Atmospheric Radiation Measurement (ARM) program. The Argonne facility will concentrate on measuring at spatial scales considerably smaller than addressed with CART. When it is fully functional, ABLE will offer atmospheric scientists the opportunity to remotely {open_quote}collect{close_quote} data in real time without necessarily leaving their home offices. Specialized computer analysis and visualization software will be developed and provided by ABLE to facilitate analysis by remote users. ABLE will host specialized field campaigns for which it can provide supplementary measurements and the required facilities for shorter-term instrument deployments. In addition, ABLE will function as the proving ground for new technologies for atmospheric boundary layer research. 1 ref., 1 fig

Coulter, R.L.

Klazura, G.E.

Wesely, M.L.

UNT Digital Library

8.13 A PLANETARY BOUNDARY LAYER OBSERVATIONAL CAPABILID IN KANSAS M. L. Wesely, R. L. CouHer, G. E. Klazura, B. M. Lesht, D. 1. Sisterson, and J. D. Shannon Environmental Research Division Argonne National Laboratory, Argonne, IL DISCLAIMER This report was prepared as an a m u n t  of work sponsore- -y an agency of the United Stat- Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumts any legal liability or responsi- bility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its usc would not infringe privately owned rights. Refer- ence herein to any spccific commercial product, proccss. or service by trade name, trademark, manufacturer, or otherwise does not accessarily constitute or imply its endorsement. rccom- mendation, or favoring by the United Statts Government or any agency thereof. I h e  views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency tbereof. .- The submitted manuscript has been authored by a contractor of the U.S. Government under contract No. W-31-109-ENG-38. Accordingly, the U.S. Government retains a nonexclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for US. Government purposes. DISCLAIMER Portions of this document may be illegible in electronic image products. Image are produced from the best available original document. A PLANETARY BOUNDARY LAYER OBSERVATIONAL CAPABILITY IN KANSAS M. L. Wesely,’ R. L. Coulter, G. E. Klazura, B. M. Lesht, D. L. Sisterson, and J. D. Shannon Environmental Research Division Argonne National Laboratory, Argonne, IL 1. INTRODUCTION An initiative is underway to establish the Argonne Boundary Layer Experiments (ABLE) facility to provide continuous, long-term observations of the planetary boundary layer (PBL) with state-of-the-art instruments. Planning for ABLE began during 1995, and implementation is expected to be mostly complete by 1998. ABLE will be located within the area now occupied by the Southern Great Plains (SGP) Cbud and Radiation Testbed (CART) site of DOE’S Atmospheric Radiation Measurement (ARM) program (Schwartz and Stokes, 1994). The Argonne facility will concentrate on measuring at spatial scales considerably smaller than addressed with CART. When it is fully functional, ABLE will offer atmospheric scientists the opportunity to remotely gcollect” data in real time without necessarily leaving their home offices. Specialized computer analysis and visualization software will be developed and provided by ABLE to facilitate analysis by remote users. ABLE will host specialized field campaigns for which it can provide supplementary measurements and the required facilities for shorter-term instrument deployments. In additiin, ABLE will function as the proving ground for new technologies for atmospheric boundary layer research. 2. INTERACTIONS WITH OTHER PROGRAMS The ABLE facility is intended to be an instrumentation and data resource for a wide variety of concurrent research efforts. In addition to supporting research planned by Argonne scientists, data from ABLE will be used by scientists associated, for example, with the Cooperative Atmosphere-Surface Exchange Study (CASES), an initiative being prepared by a national coalition of scientists representing the disciplines of atmospheric science, hydrology, ecology, chemistry, and education. Atmospheric sciences efforts proposed by CASES focus on problems in the PBL. One problem addressed is the lack of sufficiently comprehensive data sets on the PBL in a variety of synoptic conditions to test parameterization schemes designed to represent PBL and surface processes in weather and climate models. Typical data sets document fluxes and turbulence but the forcing terms are unknown or are not included in PBL sets; thus, researchers testing parameterization schemes generally resort to large eddy simulation data. The resulting model data are restricted to homogeneous Corresponding author address: Marvin L. Wesely, Bldg. 203, ER, Argonne National Laboratory, Argonne, IL 60439; e-mail <mlwesely@anl.gov>. conditions and steady barotropic forcing, and the comparisons focus on turbulence quantities. Uncertainty exists, for example, on whether the wind profiles produced by models for the PBL are realistic. In addition, schemes need to be developed to account for subgrid-scale surface heterogeneity. ABLE will provide mean PBL profile data in a variety of situations and comprehensive PBL data during episodic field experiments; such data will allow CASES and other researchers to explore these issues. Another problem addressed by CASES is the difficulty in documenting in sufficient detail the interactions between the PBL and mesoscale storm phenomena. For example, the effects of PBL heating on the diurnal variation of cold fronts are not well known. With a cloudy area north of a front in the central United States, the greater heating to the south leads to larger changes in temperature and wind across the front during daytime hours. However, the PBL models used in current mesoscale weather models are tuned to horizontally homogeneous, steady-state conditions. ABLE will provide the needed dense set of observations to evaluate PBL processes during frontal conditions. A long-term effort is needed to sample the various types of frontal passages with sufficient statistical significance; the wide array of instrumentation provided by CART and other observational facilities in the southern Great Plains can supply the larger scale information needed. 3. APPROACH A central location within the SGP CART site is desirable where the terrain, surface vegetation, and climatic conditions are most representative of the overall site. The facility should be in a watershed that is or can be well characterized hydrologically, so that hydrological studies like those proposed by CASES can be conducted in the area. A minimum size for the study area is approximately 80 km by 80 km. The Walnut River Watershed just east of Wichita, Kansas, satisfies these criieria. The ABLE facility, when mature, will provide access to data streams from a suite of atmospheric measurement instruments; install, maintain, and augment the suite of instruments; observe the daily operation and note the quality of the data; provide the opportunity for scientists to augment the facility instrumentation and conduct specific studies within the facility area or including the facility area; and provide data streams that augment CART data streams. The ABLE facility will consist of a series of sites located throughout the area, each of which will contain a minimum set of atmospheric observation systems (e.g., near-surface winds, temperatures, moisture, soil .L 8.13 moisture), some of which will be augmented with ground- based remote sensing instrumentation. For adequate investigation of small-scale phenomena and their interactions with large-scale processes, averaging times will be as small as possible. Novel methods for operating the remote probing instrumentation will be developed to maximize data products. For instance, heat and momentum flux can, in principle, be obtained from radar wind profiler and radio acoustic sounding systems (RWP-RASS); however, proper sampling techniques must be developed if the long-term averages of winds and temperatures are to be preserved. The data from each location will be collected nearly in real time at a site centrally located within the ABLE area. On-site personnel will monitor the data at the central site to ascertain the operational status of the instrumentation and implement necessary changes. The data will be available to interested scientists through Internet connections. 4. INSTRUMENTATION Figure 1 shows the planned locations of instruments in the Walnut River Watershed. The minimum set of equipment and variables observed at ABLE includes three remote sensing sites (RSSs) each containing a 91 5-MHZ RWP-FiASS to measure wind speed, direction, and virtual temperature in the PBL. Winds and temperatures are two of the primary variables that describe the state of the atmosphere. The change with height of these parameters determines the atmospheric stability and is critical to vertical transport of energy and momentum. Measurements at three locations are necessary to resolve spatial waveforms, particularly in the nocturnal boundary layer; instruments at three locations also begin to provide enough information for divergence calculations and budget studies. Another component of each RSS is a high-frequency Doppler acoustic sounder (a minisodar) to measure wind and turbulence profiles between heights of 10 m and 200 m. Three systems will be necessary, as above, to resolve spatial waveforms. These systems provide the near- surface detail and time resolution not available from profilers, particularly in stable conditions. A central site (CS) will be equipped with a lidar ceilometer and a radiosonde system. The lidar ceilometer will measure cloud base heights and, in some cases, mixed layer height; both are critical measurements that describe the vertical structure of the PBL over comparatively large scales. These parameters also describe the link between the local near-surface energy transfer and dynamics in the free troposphere. The radiosonde system will be used to measure wind, temperature, and moisture profiles. Direct measures of temperature and moisture through and above the mixed layer will remain indispensable, at least until remote sensors become much more reliable and accurate. The data acquired at large altitudes will provides tie-in to large scale processes that affect the PBL. A centralized data collection system housed in a trailer at the CS will facilitate on-site data quality control and will make data rapidly available for ongoing experiments. In addition, the CS will have an extra instrument pad equipped for power and communications . . . . . . . . . I l i f e  : : : : : . . . . . . . . Cs: cantraldte Bss: remote sensing site s m  * d a c e  flux *it0 Figure 1. Layout of ABLE components in the Walnut River Watershed in Kansas. The shaded area on the right-hand side indicates that the surface is mostly grasslands, and the unshaded area on the left-hand side of the Watershed is mostly tilled agricultural lands. to accommodate visiting scientists who need to operate instrumentation at the ABLE site. Up to five surface flux stations (SFSs) will be established to measure surface sensible and latent heat fluxes and ground heat storage. These stations will provide the most basic and necessary information about the exchange of energy between the atmosphere and the underlying surface. A series of surface budget measurements over the ABLE site will be basic to evaluation of surface heterogeneity (land use, soil type, vegetation) and its effects on mesoscale structures and circulations. Such measurements will be important for connecting satellite data to "ground truth." In addition, each SFS will have the means to measure soil moisture and temperature, which are critical elements in understanding spatial differences in surface energy budgets. A satellite data receiver-processor will be employed to assess surface variability across the facility and will be used in tandem with surface measurements to develop accurate methods for integrating surface input to atmospheric circulations. New instrumentation under development includes a volume-imaging minisodar to measure wind components at multiple heights over a three-dimensional volume with a characteristic dimension of approximately 100 m. This device will provide a means for studying the smallest 8.13 atmospheric spatial scales in three dimensions independent of time. Most profilers and sodars rely on a time series to provide one horizontal dimension and do not sample in the dimension perpendicular to the wind. The volume-imaging sodar will be able to resolve the three-dimensional wind fieid at each position within the volume, something not possible with scanning radar or lidar. Because advances in technology will provide new instrument systems and data processing systems and because new scientific techniques will be developed continually. reassessment of technology and science will be part of this effort. New instrumentation could be developed, evaluated, and tested or in operational use at ABLE. For example, various techniques to measure vertical profiles of water vapor continuously with ground- based remote sensing of the PBL are being developed for the ARM program, but the costs of the instrumentation are still high. The production of high-quality data sets from ABLE will be extremely important. Procedures for assurance and control of data quality will be developed, and scientific algorithms will be constructed to provide processed data streams from one or more instruments. The data will need to be "packaged" in a format that is easily accessible and user friendly. The effectiveness of various data streams will be enhanced by use of a data assimilation mesoscale model, which will be set up to operate continuously with the data from ABLE and other sources. 5. CURRENT STATUS The current status of ABLE can be examined on the World Wide Web at http://gonzalo.er.anI.gov/new. html. Samples of data and brief descriptions of instrumentation are being added to this Web site. The locations of the RSSs have been fixed, and installation of the RWP- RASSs is expected to be completed during the fall of 1996. The CS will also be established during the fall of 1996, but instrumentation might not be installed until 1997. Equipment for two of the SFSs has been purchased and will be installed in early 1997. 6. ACKNOWLEDGMENTS This work was supported by the U.S. Department of Energy, Office of Energy Research, Office of Health and Environmental Research, Environmental Sciences Division, under contract W-31-109-Eng-38. 7. REFERENCES Stokes, G. M., and S. E. Schwartz, 1994: The Atmospheric Radiation Measurement (ARM) program: Progammatic background and design of the cloud and radiation test bed. Bull. Amer. Meteor. Soc., 75, 1201-1221. 

A planetary boundary layer observational capability in Kansas

https://digital.library.unt.edu/ark:/67531/metadc677971/m2/1/high_res_d/475656.pdf

A planetary boundary layer observational capability in Kansas

Abstract

Similar works

Full text

Available Versions

UNT Digital Library