National Center for Atmospheric Research Annual Scientific Report Fiscal Year 1984 Submitted to National Science Foundation by University Corporation for Atmospheric Research March 1985 iii CONTENTS INTRODUCTION..... ................. **.* ....*.0000 .. e.g................ v ATMOSPHERIC ANALYSIS AND PREDICTION DIVISION.............................. 1 Significant Accomplishments ........ .. .............. 1 AAP Division Office.................................................. 3 Mesoscale Research Section ........................................... 6 Climate Section ccccce ccc............c 11 Large-Scale Dynamics Section .......... ...... .......... 18 Oceanography Section.. ............................... .. 26 ATMOSPHERIC CHEMISTRY AND AERONOMY DIVISION ............................... 35 Significant Accompishments................................ 36 Atmospheric Gas Measurements Section............. .................. 37 Chemical and Aeronomical Modeling Section ............................................. .. 42 Global Observations, Modeling, and Optical Techniques Section ............ ... ..... ...c 47 Precipitation Chemistry, Reactive Gases, and Aerosols Section... ...................... ........ 53 Director's Office.... c ce....... ..... c................... 664 ACID DEPOSITION MODELING PROJECT.... ...............................e.ge c e 69 Significant Accomplishments... ................... ... 69 Meteorology .................................... 70 Chemistry.................................... 73 System Integration and Validation .................................. 75 Engineering Model . ............................................ 78 HIGH ALTITUDE OBSERVATORY g........................................ e*e... 81 Significant Accomplishments ......... e............................. 81 Solar Atmosphere and Magnetic Fields Section.... ...................................... 82 Solar Variability Section eg .................... g...... .... 87 Coronal/Interplanetary Physics Section ............................... 93 ADVANCED STUDY PROGRAM .. .. ............................ 103 Significant Accompl ishmentse e. ge e.........................ee.**..* 103 Visitors Program ................................... ............. .. 104 Other ASP Staff Researchil......................ec...... ... 111 Environmental and Societal Impacts Group.. ... ............................. 112 iv CONVECTIVE STORMS DIVISION.... ........................... 09..... 0 123 Significant Accomplishments ....... ................................ 124 Hail Growth Studies .................................................. 125 Thunderstorm Microphysics and Electri fi cati on .................0 fat.................... 130 Dynamics of Convective Storms and Mesoscale Interactions...................... ...........134 Cumulus Clouds: Structure, Evolution, and Entrainment...................................... 141 Numerical Modeling of Cloud Processes................................ 145 Instrument Developm ente.... ............................. 150 Crystallography..................... 155 SCIENTIFIC COMPUTING DIVISION.....0.................................. 159 Significant Accompl i s hments . .. ........ .. .. .. .. .. 159 Organization ..........00000000000000000000000000.............. .. .. ... 161 Advanced Methods Section.. .. .................... 164 Data Support Section.................... 165 Systems Section........................................... 167 User Services Section.............. ............ 170 Computer Operations and Maintenance Section..................... 174 ATMOSPHERIC TECHNOLOGY DIVISION .. ... .....................................193 Statement of Goals ..* 0 000...........* 000 0 * 0 0..................0 0193 Strategy ...... .*.. ............ 0..00 00 0000 0 ..0 .. ... 0 0 0 00 .. 0 .. 193 Significant Accomplishments ........................ ............... 194 Organization............................................... 195 Research Aviation Facility........................ ........ 195 Field Observing Facility........................................ 208 Global Atmospheric Measurements Program............ ..... 217 Design and Fabrication Services ...................................... 220 PUBLICATIONS ..... .. ..@.. ... 2.......5225 v INTRODUCTION This report was conceived to give our sponsor, the National Science Foundation, a comprehensive summary of NCAR's work during the preceding fiscal year, as required by the NSF-UCAR contract governing the operation of NCAR. Its preparation is also a valuable part of the NCAR planning process, enabling the organization to examine and assess the work of the past year. And it provides a reference document that many of our staff, visitors, and university colleagues find useful. The scope of NCAR research and facilities programs is such that even a document this thick can only be a relatively quick-look summary of all the work done here, but the overall flavor of NCAR's work is given. Some of the hallmarks of NCAR's programs are: * A research program of the highest quality, the essential foundation on which the success of the organization must be built * An array of facilities intended to meet and anticipate the needs of the entire atmospheric sciences community, and identified and designed in consultation with the community * Activities across the organization carried out in extensive collaboration with the university community, as evidenced by the fact that more than 30% of the staff's scientific publications are co-authored with scientists from other institutions, by the hundreds of scientists from other institutions who use NCAR's facilities, and by the extensive use of NCAR and its staff for the planning of national research programs and initiatives. More than most sciences, the atmospheric sciences are difficult to separate cleanly into fundamental and applied research. For the preponderance of atmospheric research efforts, the benefit of the knowledge being sought is quite clearly a practical application, somewhere downstream. Nonetheless, it is equally clear that there are great variations in the distance between the research and the goal of practical applications, in the specificity with which the application can be defined, and in one's certainty that the goal can actually be reached. In these respects, most NCAR research programs, like most of those in the university community, are and should be at the long-range and speculative end of the research spectrum. An example is atmospheric chemistry, which has experienced a revolution in the past ten years that will continue for another decade or more. The chemical processes by which the atmosphere establishes and maintains itself, in interaction with the life, land, and oceans beneath it, are only now beginning to be identified and understood. Until far more fundamental knowledge of these processes is produced and integrated into an overall understanding of our planetary system, we can give only interim answers to such puzzling and pressing questions as those surrounding acid rain, or the effects on the atmosphere of increasing carbon dioxide release, or the clearing and burning of much of the earth's tropical forests. vi The quest for this information is difficult, requiring sustained effort over many years, involving scientists expert in many subdisciplines, and using extensive facilities and financial and logistic support. Undertaking such long-range efforts, in concert with scientific colleagues from across the nation and the world, is a principal reason for the existence of NCAR. Indeed, NCAR, embedded in the university community and provided stable support by a federal sponsor devoted to the support of basic research, is ideally, and in some respects uniquely, suited to be the site and the focus for such research efforts. What is true of atmospheric chemistry is true in the other major areas of NCAR research--atmospheric dynamics, climate, convective storms, solar and interplanetary physics, the theory of turbulence. Therefore, most of the progress reported each year in this volume is in the form of significant milestones reached along the long roads of science. Some examples this year are the first detailed airborne measurements of hydrogen peroxide, which is believed to be a vital link in the chain of events leading to acid rain; increased understanding of the dynamical relationships between the El Nino warming of the equatorial Pacific waters and climatic anomalies in northern mid-latitudes; the resumption of observations of the solar corona following repair of the Solar Maximum Mission satellite by NASA astronauts; an increased understanding of the latitudinal dependence of angular velocity in the solar atmosphere; and the completion of the task of processing all the aircraft data from the largest investigation of convective clouds and storms ever mounted. From time to time, we become involved in efforts that not only possess great scientific interest, but also can contribute to a practical application in the present or the near term. Two examples of such work, discussed in this report, are efforts to contribute directly to aircraft safety through a program to detect and warn of severe downbursts near airports and to develop an acid deposition model that can be used to assess the severity and distribution of acid rain and dry deposition on a regional basis. We are proud to be involved in these significant contributions to the nation's immediate welfare. As we continue our longer-range work, we will take advantage of the opportunity to contribute