National Center for Atmospheric Research Annual Scientific Report January - September 1982 Submitted to National Science Foundation by University Corporation for Atmospheric Research March 1983 iii CONTENTS INTRODUCTION ........ .. .............................................. ATMOSPHERIC ANALYSIS AND PREDICTION DIVISION .......................... 1 AAP Division Office. .................................. 4 Mesoscale Research Section . .................................... 6 Climate Section ...................... 13 Large-Scale Dynamics Section. ............................ 21 Oceanography Section..............................................30 ATMOSPHERIC CHEMISTRY AND AERONOMY DIVISION. ....................... .37 Precipitation Chemistry, Reactive Gases, and Aerosols Section...................................39 Global Observations, Modeling, and Optical Techniques Section. ................ 49 Atmospheric Gas Measurements Section.. .......................... 54 Chemical and Aeronomical Modeling Section ......... .. .. .. .. .... .... .. .58 HIGH ALTITUDE OBSERVATORY..............................................67 Coronal and Interplanetary Physics Section. .................... ......... ............ ....... .68 Solar Variability Section. .75 Solar Atmosphere and Magnetic Fields Section................................................ 83 ADVANCED STUDY PROGRAM.......................................................... .91 Visitors Program .................................................. 91 Other ASP Staff Research ............... .......................... 96 Environmental and Societal Impacts Group ........................................ 97 CONVECTIVE STORMS DIVISION ...................................... ... 103 Ice Initiation in Colorado Storms ... .1..................04 Storm Inflow Organization ...................... 106 Instrument Plans and Evaluations.................................107 CSD Modeling Highlights..........................................110 iv Interactive Analysis of Doppler Radar Data................................................... 112 Aircraft Posi ti oning. ......................................... .113 Hail Studies........................................... .......... 114 Mesoscale Aspects of High Plains Convective Systems. ... ..... .. ............116 Investigation of the Severe Storm Environment on 2 August 1981..........................117 Mesoscale Analysis of a Tropical Squall Line: The Importance of Advection of Condensed Water Aloft ...........................118 Hurricane Rainband Studies: What Happens to Low-Level Air?.................................. 19 Radar Study of Convective Cells in Mesoscale Systems in GATE. .................................. 120 How do Cumulonimbus Clouds Transport Momentum? ... .............. .............. ........ .. .* .123 Physical Characteristics of Cumulus Clouds Based on Aircraft Observations near Cloud Base in CCOPE........................o.. ........... 125 A Large Cumulonimbus Cloud Observed in CCOPE.... .................... ............................... 127 Data Management. ....................................0 128 SCIENTIFIC COMPUTING DIVISION........................................133 Current Systems...................................133 Services.. .. 133 Organization. ............................................... 133 Data Support Section............................................134 Advanced Methods Group........................140 User Services Section..........................145 Computer Operations Section............................e. 154 Systems Section.. ........................................... 159 ATMOSPHERIC TECHNOLOGY DIVISION ............................ 179 Design and Fabrication Services .................................. 181 Research Aviation Facility .......... .................. 182 Field Observing Facility.197 Global Atmospheric Measurements Program.........................20 National Scientific Balloon Facility............................210 P UBL ICATI ONS ......................................... ........ 217 v INTRODUCTION The purpose of this report, written by NCAR division directors and their colleagues, is to give the National Science Foundation (NSF) a concise pro- grammatic description of the work carried out by NCAR from January through September 1982 in fulfillment of the contract between NSF and the University Corporation for Atmospheric Research (UCAR) for the operation of NCAR. (This nine-month report constitutes a transition from a calendar year report- ing period to a fiscal year period; the next one will cover a full fiscal year.) The Annual Scientific Report is also intended to be a reference docu- ment on NCAR's work for the use of colleagues in the atmospheric sciences community. NCAR's two missions--to conduct atmospheric research on processes and phenomena of major scientific importance and to provide advanced facilities to the research community--come together in the broad array of projects that are collaborative with university scientists and that use NCAR computational and field facilities. During the report period, the most prominent field experiment was the Joint Airport Weather Studies (JAWS) project, which shed much new light on "downbursts," sharp discontinuities in air motions that pose severe hazards to aircraft taking off and preparing to land. This project involved par- ticipation by the Universities of Chicago, Wyoming, and Tennessee; NCAR; the National Oceanic and Atmospheric Administration; the Federal Aviation Admin- istration, and the United Kingdom's Royal Aircraft Establishment. It was characterized by twin opportunities: to add to our basic knowledge of atmo- spheric processes and, at the same time, to address an important practical problem. With adequate support, the techniques used in JAWS to detect, measure, and track downbursts and to warn pilots about them can be applied at busy airports in not more than four to five years. In theoretical work, 1982 marked the completion, documentation, and first use of the NCAR "model zero" community climate model. This model, developed with the advice of a steering committee composed of scientists from seven universities, has already had more than a dozen users, and we expect that as our second CRAY-1A computer comes on line later in 1983, the number of users will more than double. These two examples of collaborative work are backed up by many other such efforts described in this report. They range across every area of NCAR's work, from atmospheric dynamics and chemistry to the interactions of the atmosphere with oceanic and solar phenomena. The entire UCAR research community can take pride in the vigor, breadth, and excellence of its research efforts in a scientific realm of such impor- tance to the nation and the world. NCAR plays, and will continue to play, an integral part in these efforts, through innovative, productive programs of research and facility development and operation. vi The 1980s present us with a range of special opportunities to advance the science and its usefulness. Obvious examples are in the realms of stormscale phenomena, atmospheric chemistry, and climate. I sense that the NCAR staff and their university colleagues are enjoying the challenge. Wilmot N. Hess Director ATMOSPHERIC ANALYSIS AND PREDICTION DIVISION The Atmospheric Analysis and Prediction (AAP) Division studies the behavior of the atmosphere and the ocean on spatial scales ranging from the microscale (for example, turbulence) to the global scale, and on time scales ranging from seconds to millions of years. AAP continues to explore current questions in climate, forecasting (short- and long- range), oceanography, and mesoscale meteorology (including turbulence, moist convection, and the environment of severe local storms). AAP studies the physical processes governing atmospheric and oceanic behavior using observational, numerical, and theoretical methods. Observational studies provide ground-truth analyses of actual atmospheric structure and behavior for diagnostic studies and theo- retical interpretation. Numerical simulations provide more detailed and precise data sets for diagnostic and theoretical studies than are avail- able from direct observations and permit the theoretical investigations of complex circulations and feedback mechanisms for which analytic methods are not suitable. Theoretical research complements the other two methods by explaining fundamental principles that govern atmospheric and oceanic behavior. Although each of the above methods of research requires a degree of specialization, the most productive scientific research generally occurs when these methods are used together to attack scientific problems. The administrative components of AAP and the principal topics of research in 1982 are: * Division Office (Richard Anthes, Director) Regional-scale numerical modeling Theory and parameterization of surface processes affecting climate * Mesoscale Research Section (John Wyngaard, Head) Convective-storm and tornado modeling Mountain waves and orographic precipitation Alpine Experiment Marine stratocumulus boundary layers Boundary-l ayer measurements Theory and parameterization of thermal convection and turbulence * Climate Section (Warren Washington, Head) Climate modeling (Community Climate Model-CCM) Global observational studies (for example, Global Weather Experiment analyses, southern oscillation, global tele- connections, climate statistics) Structure of large-scale waves Natural variability and potential predictability 2 ATMOSPHERIC