NCAR Technical Notes

The NCAR Technical Notes Collection comprises over 500 scientific and technical reports, issued by NCAR divisions and programs, and consists of data compilations, theoretical and numerical investigations, and experimental results.


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CCM2 Datasets and Circulation Statistics
CCM2 Datasets and Circulation Statistics
This technical report documents the data findings from simulations and condensations which includes actual simulations, climatological monthly averaged sea surface temperature; 10 and 20 year simulation cases; simulation with BATS and other resolutions.
CEDAR Database Committee Report
CEDAR Database Committee Report
This report discusses the Data Base as it is today, assesses CEDAR community utilization of the Data Base and makes recommendations for its future development. Section 2 covers the history and current status of the Data Base. In Section 3 we discuss operations and available resources, including personnel and computer facilities. Utilization of the Data Base is covered in Section 4 and Tables 1-4. The format used to store data has remained unchanged since the creation of the Incoherent Scatter Data Base in 1985. This format was designed with incoherent scatter data in mind, and is not entirely satisfactory for certain other data types, such as images. In Section 5 we discuss modifications to the format to accommodate additional types of data, and new requirements such as telescience. Smooth functioning of the Data Base requires that there be clear agreements among the parties involved in acquiring, handling, and using the data. This is covered in the Data Base Rules of the Road. New developments in computer technology, such as the World Wide Web, require a reevaluation of the current Rules of the Road. In Section 6 we recommend a modification to the Rules of the Road which will simplify the procedure for accessing the data through the Web. Education and informing the general public about CEDAR are important functions of the Data Base, and we discuss this in Section 7. In Section 8 we discuss future directions of the Data Base, including telescience and computer aided collaboration. The conclusions of this report are summarized in Section 9.
Calculation of the Electrostatic Field Within a Structure of Uniformly Spaced Coaxial Conducting Loops
Calculation of the Electrostatic Field Within a Structure of Uniformly Spaced Coaxial Conducting Loops
For research and engineering applications a nearly uniform electrostatic field within a given volume of free space can be created inside a series of identical, evenly spaced coaxial loops which are charged to uniformly incremented voltages. In this report the electrostatic field of such a structure is calculated using two methods: 1) using elliptic integrals for a finite set of round loops of circular cross section, and 2) using Laplace's equation with approximate boundary conditions for an infinite set of square loops of elliptical cross section.
Calibration of the HAO Standard Opal Filter Set
Calibration of the HAO Standard Opal Filter Set
This document describes the motivation for recalibrating the opal filters to know the transmittance values in spectral regions above and below those used in 1970. The spectral regions chosen were 450 nm, 550 nm, 650 nm and 800 nm. In summary, it is felt that the use of the direct radiation from the sun, thereby insuring the proper geometry for the measurements, and employing a silicon photodiode detector,whose response is extremely linear over a wide dynamic range, have significantly improved the accuracy of the transmittance measurements.
Calibration of the NCAR Sabreliner Research Static Pressure Source With a Trailing Cone Assembly
Calibration of the NCAR Sabreliner Research Static Pressure Source With a Trailing Cone Assembly
Trailing cone results verify that pressure corrections for the NCAR Sabreliner derived from tower flyby data can be extrapolated to higher Mach numbers and higher altitudes with valid results. Residual static pressure errors are small, on the order of 0.1-0.3 mb, corresponding to altitude errors of 20-30 ft for altitudes of 15,000-39,000 ft and Mach numbers of 0.59-0.76.
Carrier Balloon Test Flights From Oakey, Australia, January 1973
Carrier Balloon Test Flights From Oakey, Australia, January 1973
This report summarizes the results of the Carrier Balloon Tests from Oakey, Australia, in January, 1973. The main objectives of these tests were to check out the launch hardware and launch techniques; provide a significant sample from which to determine probable balloon life; to qualify the Roberts overpressure valve in flight; and to determine the temperature levels in the instrument compartment and dropsonde tubes.
Case Studies on Convective Storms / Case Study 1, 13 July 1978: First Echo Case
Case Studies on Convective Storms / Case Study 1, 13 July 1978: First Echo Case
On 13 July 1978, a long-lived storm complex developed in southeastern Wyoming, and was well observed by aircraft and radars. The potential instability was weak to moderate on this day, and the environmental shear was fairly strong, resulting in an airmass thunderstorm of multi-cellular character. Data from the many penetrations by instrumented aircraft characterize various stages of development of seven cells that formed on the storm's western flank. Cloud particle sizes and types suggest accretion (riming) as the dominate particle growth mode. Further generalizations are made from quantitative photographic observations and single Doppler radar data. Aircraft measurements below cloud revealed extensive inflow regions and often showed strong updrafts, mainly on the west and southwest flanks. Rarely was an organized downdraft detected, and no gust front or outflow boundary was evident in any of the data. The study focuses on first-echo formation and cell development, though the major cells formed a moderately intense storm which lasted for several hours.
Case Studies on Convective Storms / Case Study 1. 22 June 1976: First Echo Case
Case Studies on Convective Storms / Case Study 1. 22 June 1976: First Echo Case
This is one of a series of documents reporting data on aircraft penetrations in convective clouds, ranging from cumulus congestus to thunderstorms, in northeastern Colorado and adjacent portions of Wyoming and Nebraska. Specifically noted is the maximum reflectivity encountered by the sailplane measured as 15-20 dBZe. Particle camera data indicates that precipitation-sized particles are exclusively ice; no liquid drops greater than cloud droplet size are detected.
Case Studies on Convective Storms / Case Study 10, 22 July 1975: Mature Storm Study / a Conceptual Model Synthesized From Microphysical and Dynamic Observations of a Multicell Thunderstorm
Case Studies on Convective Storms / Case Study 10, 22 July 1975: Mature Storm Study / a Conceptual Model Synthesized From Microphysical and Dynamic Observations of a Multicell Thunderstorm
This Technical Note is a case study of one of the storms examined in the 1975 field season of the National Hail Research Experiment, during which the two primary observing instruments were the CP-2 10 cm radar and the South Dakota School of Mines and Technology armored T-28 aircraft that had just been instrumented with new cloud physics probes. A complex multi-cell thunderstorm was penetrated with the armored T-28 aircraft. The T-28 carried a comprehensive suit of instruments to measure specific, critical parameters in the thunderstorm. The instrumentation package included a foil impactor for measuring particles larger than 1 mm, a Particle Measuring Systems (PMS) two-dimensional cloud probe for measuring 25 lim to 1 mm diameter particles, and a PMS Forward Scattering Spectrometer Probe (FSSP) for measuring droplets 2-30 lpm diameter. The National Hail Research Experiment's (NHRE) CP-2 radar was located in a prime position to acquire optimum data on this storm. A Doppler processor was integrated into the CP-2 system. The location and motion of the storm were fortuitous in that the storm moved almost directly away from the radar, and 65�� to the right of the environmental winds. The data set is examined in detail. The key to understanding the data lies in dividing the storm into its component cells (parts) and examining the data in the context of cell lifetimes. Thirty-nine cells were delineated as part of the storm which lasted over two hours. Six of these cells were penetrated by the T-28, two of them twice. A conceptual model is developed by considering the total interactive series of cells and the detailed measurements within specific cells relative to the total radar study and the detailed radar analysis of each cell. Using the analyzed data, cross sections are developed to show the spatial and temporal parameter evolution through the life of a typical cell in a multicell storm. Evidence exists for the recirculation of ice crystals in areas of subdued convection and downdrafts to allow time for growth of cloud elements to hail embryo sizes followed by subsequent diffusion into updraft areas where the ingredients for rapid growth of these embryos to hail sizes exist.
Case Studies on Convective Storms / Case Study 2, 22 July 1976: First Echo Case
Case Studies on Convective Storms / Case Study 2, 22 July 1976: First Echo Case
This is one of a series of documents reporting data on aircraft penetrations in convective clouds, ranging from cumulus congestus to thunderstorms, in northeastern Colorado and adjacent portions of Wyoming and Nebraska. The data suggest that the precipitation process was well-developed during the sailplane penetration of the two cells, which took place 15-35 minutes past the initial formation of the -5 dBZ reflectivity level.
Case Studies on Convective Storms / Case Study 3, 8 June 1976: First Echo Case
Case Studies on Convective Storms / Case Study 3, 8 June 1976: First Echo Case
Extensive coverage by three aircraft in the inflow region of a maturing storm highlighted the investigation of 8 June 1976. The synoptic conditions supported convection of moderate strength, with the activity initially forming and organizing northeast of Cheyenne. The data from the aircraft investigations are presented in relation to the radar data. The data show the interactions of individual cells with each other and with the storm mass to be varied and complex.
Case Studies on Convective Storms / Case Study 4, 27 July 1976: First Echo Case
Case Studies on Convective Storms / Case Study 4, 27 July 1976: First Echo Case
On 27 July 1976, a relatively small, weak storm was investigated by the NCAR/NOAA instrumented sailplane in coordination with NCAR Queen Air 306D. The potential instability was weak on this day, and the investigated storm probably was initiated from the observed surface convergence which resulted from outflow of an older storm to the northwest and/or surface topography. The sailplane made an extended penetration from 1635 to 1715 covering ���3400 m in altitude with weak updrafts initially, growing to moderately strong updrafts and then finally weak downdrafts. Ice particle concentration and size both increased throughout the penetration to about 100 l ����� and 2-4 mm graupel. The Queen Air measured fairly weak updrafts at cloud base and mixed thermodynamic conditions. Later subcloud passes (���1700) revealed decaying conditions, weak downdrafts and lower &#x0398 e values. The storm had the characteristic life cycle of a simple rainshower.

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