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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Vertical Interpolation and Truncation of Model-coordinate Data
Vertical Interpolation and Truncation of Model-coordinate Data
This technical note explores the advantages and disadvantages of using global analyses on 1) pressure level surfaces, and 2) model (sigma or hybrid) level surfaces and the issues of interpolation from one to the other, time averaging, changing resolution, and extrapolation below ground. Documentation is provided of the new algorithms implemented in the Community Climate Model (CCM) modular processor for deriving pressure-level data from model-level (hybrid or sigma) data.
Vertical Profiles of HTO, HDO, and H2O in the Troposphere
Vertical Profiles of HTO, HDO, and H2O in the Troposphere
This document presents vertical profiles of tritium, deuterium, and water vapor in the troposphere that was obtained by NCAR at various times from 1966 through 1973. These data enable development of more realistic models of the transport and rainout of tritium as well as a more realistic estimate of the tropospheric residence time of water vapor. Explanations of relevant tables and figures are included.
Wind Energy Resource Assessment : Information Production, Uses, and Value - Survey Report
Wind Energy Resource Assessment : Information Production, Uses, and Value - Survey Report
High-quality information about the wind resource at candidate wind farm sites is essential to continue to guide the rapid growth of wind energy in the United States and around the world. In the effort to produce better information through improved wind resource assessment (WRA) methods, input from people within the industry who produce and use this information is key. During the summer of 2013, researchers at the National Center for Atmospheric Research conducted an online survey of WRA experts (both producers and users of WRA information) to learn about current practices, priorities, and informational needs. Key findings from this survey include: 1) Wind resource assessments are produced by a variety of actors, including wind energy developers, consultants, and energy utilities, using several different methods and data sources; 2) Use of wind resource assessments also spans a wide range of different organizations across multiple sectors of the wind industry; 3) Respondents viewed overprediction in wind resource assessments as an ongoing problem for the wind energy industry; and 4) Respondents overwhelmingly thought that quantifying the uncertainty in wind resource assessments would be valuable, though they also cited several barriers to its use in the wind energy development process. Respondents’ consensus about the need for high quality site data as well as improved methods for using that data to produce wind resource estimates should help to guide future efforts to serve this community’s needs.
Wind Tunnel and Field Investigations of Shapes for Balloon Shelters
Wind Tunnel and Field Investigations of Shapes for Balloon Shelters
This report discusses the results of a series of wind tunnel and field tests performed in support of a program to develop a balloon inflation and launch shelter. The study discusses scaling criteria for simulating a shelter; velocity, turbulence, and frequency spectra downwind of four basic shelter shapes; the effects of screen materials on a shelter's efficiency; and the influence of the presence of a simulated balloon upon the effectiveness of the shelter.
Workshop Review: Management of Data Collected in GRAMP (Gulf Region Atmospheric Measurement Program) 22-24 July 1991
Workshop Review: Management of Data Collected in GRAMP (Gulf Region Atmospheric Measurement Program) 22-24 July 1991
In response to the demolition and subsequent burning of the Kuwait oil fires this report summarizes a workshop that was held July 24-26, 1991 at the National Center for Atmospheric Research (NCAR) to discuss a plan to gather all the atmospheric measurements that are being made in the Gulf region and make them available for general dissemination. This workshop was initiated by the World Meteorological World Meteorological Organization and co-sponsored by the National Oceanic and Atmospheric Organization.
Workshop Summary: Aircraft Mission Measurement Strategies for the NASA Subsonic Assessment Program
Workshop Summary: Aircraft Mission Measurement Strategies for the NASA Subsonic Assessment Program
The National Aeronautics and Space Administration (NASA) has initiated a major program to assess the impact of tropospheric aircraft on the atmosphere. The Subsonic Assessment program plans to conduct future field programs that will address specific scientific issues related to aircraft impact, e.g., studies of plume chemistry, contrail effects on cirrus formation, and global radiation budget, and tropospheric/stratospheric exchange processes. The first step in the planning process was the convening of a workshop to identify those atmospheric processes that would most likely be impacted by aircraft and that can be studied with in situ and remote sensing measurements from aircraft. This technical note condenses presentations and discussions of the three major facets of the workshop: identification of the primary scientific issues, review of previous applicable airborne campaigns, and preliminary measurement strategies to address the scientific issues. A number of recommendations are made with respect to aircraft utilization in general and potential flight profile scenarios in particular.
Workshop on Numerical Modeling and Physical Reality
Workshop on Numerical Modeling and Physical Reality
This report contains speakers' abstracts as presented at the workshop on Numerical Modeling and Physical Reality held at the Mesa Laboratory of NCAR on September 3-5, 1997 and one in a series of workshops presented by the Geophysical Turbulence Program (GTP) of the Advanced Study Program which includes: Opening Remarks /Boon Chye Low Simulation Geophysical Fluid Phenomena /Jim McWilliams Reality and Numerical Simulations in Astrophysics /Annick Pouquet The Role of Statistical Thinking in Physical Modeling /Mark Berliner Issues in Fluid Mechanics and Meteorology /Roger Temam The Use (and Abuse) of Models in Data Assimilation /Ron Errico Model Validation: Regional Oxidant Model and Ozone Data /Doug Nychka Tropospheric Chemistry and Urban Air Quality /Sandy Sillman Turbulent Flows in Plant Canopies /John Finnigan Reality and Models in the Atmosphere and Climate /Robert Sadourny The Water Vapor Feedback /Richard Lindzen Strategy and Tactics of Engineering Turbulence / Peter Bradshaw Challenges in Bridging LES and Physical Reality/Charles Meneveau
Workshop on Online Documentation in the Supercomputing Environment: Working Paper
Workshop on Online Documentation in the Supercomputing Environment: Working Paper
This document addresses the many issues and problems of online user documentation for supercomputers, specifically, problems of delivering online information in a heterogeneous computing environment that includes supercomputers and workstations, and lack of vendor solutions that work in diverse computing environments for diverse types of documentation. These problems have made it difficult to develop online documentation systems that have proved to be broadly effective.
in2extRemes: Into the R package extRemes. Extreme value analysis for weather and climate applications
in2extRemes: Into the R package extRemes. Extreme value analysis for weather and climate applications
This document serves as a tutorial/manual for the R package in2extRemes, which provides point-and-click windows for the extRemes package (versions greater than or equal to 2.0). The aim of in2extRemes and this document is to facilitate a shortened learning curve for performing statistical (univariate) extreme value analysis (EVA). Originally, the graphical user interfaces (windows) were provided by extRemes (versions less than 2.0), which predominantly interfaced to the R package ismev. Now, however, extRemes greater than or equal to 2.0 is a command-line (no windows) EVA software package similar to ismev, but with considerably more functionality. A brief overview of EVA is provided, as well as a tutorial on how to install, start and use in2extRemes. Knowledge of R is not required to use in2extRemes apart from a few minor commands that are detailed here.

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