The division's research models, particularly the NCAR/Pennsylvania State University Mesoscale Model (MM5) and the Clark Model, are used extensively not only for research purposes, but also for direct applications. As an aid to users of these models, the division has established a series of tutorial sessions to introduce new users to our modeling systems and to instruct them on how to run and modify the models to meet their research needs. Experienced users are informed of new features that have recently been added to the models, and the division, in turn, receives valuable input on enhancements these researchers either have made or desire to have made to the models. These tutorials will continue and, given their popularity, may be increased in frequency to meet the ongoing demand. During FY 95 the division remodeled some of its space to accommodate a classroom for training purposes. It is equipped with workstations and projection equipment, and is networked to the division's computing system. Training activities that took place during FY 95 are highlighted below.
The MM5 Web pages have been on-line since August 1995 (the URL is http://www.mmm.ucar.edu/mm5/mm5-home.html). Through these Web pages, users can find information regarding: (1) an overview of the modeling system, (2) how to obtain permission to use the model, (3) accessing the source code, (4) subscription to mesouser e-mail, (5) on-line documentation, (6) upcoming tutorials and workshops, (7) users' e-mail addresses and scientific interests, (8) refereed journal publications related to the MM5, and (9) ongoing research projects and applications of the model. A compiled list of frequently asked questions with answers and past bug fix news are also available on the MM5 Home Page.
Two MM5 tutorial classes, offered 10-13 January and 8-11 August 1995, had a total of 36 participants. The four-day tutorial classes included lectures on each component of the modeling system and hands-on practice sessions. These lectures were given by Sue Chen, Jimy Dudhia, David Gill, Yong-Run Guo, and Kevin Manning. The tutorial class participants learned to run the MM5 on the NCAR Cray Y-MP and on the workstation through these exercises.
The Fifth Annual PSU/NCAR Users' Workshop was held 14-16 August 1995. A total of 57 users from 22 institutions participated in this three-day event. The 44 presentations given by the users covered the topics of (1) model numerics, (2) visualization and workstation MM5 developments, (3) model initialization, (4) mesoscale systems, (5) topographic effects, (6) model verification, (7) mesoscale climate, (8) Planetary Boundary Layer (PBL) and surface processes, and (9) MM6. In addition to the users' presentations, five invited talks on subjects of general interest to MM5 users were given by Chin-Hoh Moeng, Piotr Smolarkiewicz, Morris Weisman, Thomas Schlatter (NOAA, Forecast Systems Laboratory, FSL), and John Michalakes (Argonne National Laboratory).
In order to provide a forum for a focused discussion on the problem of cumulus parameterization for mesoscale models, Ying-Hwa Kuo organized a mini-workshop on 11-12 September 1995 at the Foothills Laboratory, NCAR, Boulder, Colorado. Approximately 50 scientists participated in this workshop. Seventeen papers were presented, with ample time reserved for discussion. Discussion focused on the advantages and disadvantages of various cumulus parameterization schemes and approaches, the importance of momentum transport, the treatment of resolvable-scale versus subgrid- scale precipitation and their interaction, and the verification of various schemes. This workshop has stimulated interaction among cloud modelers, mesoscale modelers, and mesoscale observational scientists to work on this challenging scientific problem.
William Hall completed the first phase of the parallelization for Clark's anelastic model with interactive grid nesting, and it became operational during the past year. The method uses coarse-grain parallelism where each interactive grid is partitioned into sub-domains (blocks) of equal or nearly equal size and equivalent resolution. This coarse-grain parallelization was used in the Hong Kong project on various memory-shared machines with 4, 8, or 16 CPUs. The machines include the Cray J90 (4 CPUs), SGI Power Challenge (4, 8, or 16 CPUs) and the Cray Y-MP. This new software was used on the SGI to perform a tropical storm simulation using 62.5-m horizontal resolution. In the future, this method of solution will be extended to distributed memory systems such as the Cray T3D.
Hall added digital filtering to the large-scale initialization package of the Clark modeling system to reduce spurious noise. This procedure was successfully applied in real time during the Arizona Project field experiment in FY 95 using forecast data provided by the NOAA, FSL Mesoscale Analysis and Prediction System (MAPS) model while running on a dedicated IBM workstation.
N. Andrew Crook (joint appointment with RAP) collaborated with scientists at the Center for Analysis and Prediction of Storms (CAPS) at the University of Oklahoma on mesoscale model initialization. Convection initiation cases from the Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX) were examined with the Clark model and compared with simulations using the Advanced Regional Prediction System (ARPS), the model developed at CAPS.
Members of the Cloud Systems Modeling Group continued their interaction with and service to the atmospheric science community by making the Clark Model available for their use. An annual workshop was conducted 5-16 June 1995 with an attendance of 18. The applications of the Clark Model include a linked hydrology and mesoscale atmospheric model, convective storms, weather modification, atmospheric chemistry, winter storms, tropical convection, airflow over complex terrain, microphysics of Hawaiian rainbands, fire modeling, and boundary layer studies.
Peter Sullivan, James McWilliams (University of California, Los Angeles), and Moeng have implemented a nested-grid capability into the NCAR Large Eddy Simulation (LES) code. This code allows for two-way interactions in which the coarse-grid information is used at the grid interfaces as boundary conditions for the fine-grid motion, and the fine-grid information is fed back into the coarse grid. Using a nested grid in the surface layer, where turbulent eddies are typically much smaller than in the mixed layer, the authors carried out several simulations of a slightly convective, strong shear PBL with a varying surface-layer resolution that is up to (5,5,2) times finer in the (x,y,z) directions than the outer grid. The simulated turbulent motion is shown to fully match in the overlap region of the fine and coarse grids on an instantaneous basis. It is found that surface layer grid nesting leads to significant increases in resolved eddy fluxes and variances, especially in the vertical velocity field. Spectra of the vertical velocity variance show that its scale content shifts towards higher wavenumbers (smaller scales) and the magnitude of the peak energy is increased by more than a factor of 3. However, outside of the nested region, the average heat and momentum fluxes and spectra are only slightly influenced by the fine resolution in the surface layer. This adds support to the rationale of the LES concept, in which the global properties of the PBL motions are assumed to be insensitive to the details of the fine-scale motions near the surface.
The 1995 ASP-sponsored Summer Colloquium, held 24 July through 4 August 1995, was on "The PBL and Its Parameterization." Moeng and Sullivan were leaders of the colloquium and the associated tutorial. Moeng also taught an advanced PBL graduate course at Colorado State University during the fall 1995 semester.
The adaptive grid model COMMAS (COllaborative Model for Multiscale Atmospheric Simulation) using the generalized adaptive grid interface constructed by William Skamarock and Ming Xue (CAPS), a cloud model constructed by Louis Wicker (Texas A & M University) and Robert Wilhelmson (National Center for Supercomputing Applications, University of Illinois), and a sophisticated ice-microphysics parameterization are being used for simulations of midlatitude mesoscale convective systems, supercell storms, coastal currents, and frontogenesis associated with unstable baroclinic waves. A terrain version of COMMAS has been developed. It uses an advective formulation of the governing equations that has proven to be the most robust system for use in cloud-, meso- and synoptic-scale simulations. The model will be available in the coming year.
Daniel Hansen, Jordan Powers (ASP postdoctoral visitor), and Mark Stoelinga (visitor, University of Washington), in collaboration with the Advanced Computing Center for the Arts and Design (ACCAD) of Ohio State University, contributed to the development of a real-time MM5 outputting and interactive visualization system. The system outputs MM5 data in a special format which is then used by SGI Explorer software to render imagery as the model is running. It allows the monitoring of ongoing forecasts and the analysis of output as simulations proceed.
William Anderson and L. Jay Miller continued the support of software used for analysis and display of radar and mesonetwork data installed at NCAR and at several universities and government research agencies. Anderson added new interpolation and graphics capabilities to radar software, ported the mesonetwork software to the UNIX workstation environment, and began work on a Graphical User Interface (GUI) for the radar software. Miller tutored users of these data analysis programs. As part of the Small Cumulus Microphysics Study (SCMS) conducted during the summer of 1995 in Florida, Anderson and Miller, along with Christopher Burghart (ATD), designed and implemented a real-time version of the MMM radar data interpolator to grid conventional, constant-azimuth angle scans onto horizontal sections to aid researchers in the coordination of radar scans with aircraft cloud penetrations.
Several MMM scientists actively participated in or led other research-related workshops or meetings in FY 95. Among these were:
The division hosts a weekly seminar series. During FY 95 there were a total of 50 seminars presented of which 11 were given by MMM scientists. In FY 95 the series was coordinated by Andrew Heymsfield. Crook is the coordinator in FY 96. Upcoming presentations can be viewed on MMM's Home Page (the URL is http://www.mmm.ucar.edu/sem/1995.html).
Several MMM scientists are active in editorships and on committees, panels, or boards. These are highlighted below.
MMM scientists have participated formally in UCAR's COMET programs designed to teach operational meteorologists the latest techniques in mesoscale meteorology and weather forecasting. Staff participation during FY 95 is described below.
Weisman and Edward Szoke have been serving as subject matter experts for the new COMET distance learning module entitled "Convective Storm Structure and Evolution." The goal of this module is to establish a base level of understanding as to the environmental factors that control storm structure and evolution. It covers both the theoretical and observational aspects of convective storms, with a highlight of the module being an interactive matrix of convective simulations made for varying amounts of Convective Available Potential Energy (CAPE) and vertical wind shear that a forecaster can peruse to better understand these basic environmental controls on storm evolution. Weisman served as a lead instructor for the 1995 COMET Mesosclae Analysis and Prediction (COMAP) course for National Weather Service Science Operations Officers (SOOs). This eight-week intensive course covered many aspects of mesoscale meteorology and its applications to forecasting, and was taught in conjunction with weather service personnel. Weisman served as the primary lecturer for the summertime-weather portion of the course.
Stanley Trier was a co-leader, along with David Blanchard (RAP), of the third week of the COMET special mesoscale course which was conducted in August 1995. He planned and delivered lectures and labs to the COMET students and helped to evaluate their assimilation of the material. The course was directed by Gregory Byrd (COMET). Trier and Christopher Davis (joint appointment with RAP) also gave lectures during the COMET COMAP course led by Weisman.
Joseph Klemp serves on the COMET Advisory Panel and chairs the COMET Scientific Review Panel. Robert Gall served as a mentor for a student who was part of the COMET residence program.
The division participates in the UCAR Summer Employment Program for undergraduate minority science majors. During the summer of 1995 the division hosted two SEP students, Linsey Marr, Harvard University, sponsored by Kenneth Davis (visitor, University of Colorado), and Joan Sanchez Nash, Metropolitan State College of Denver, sponsored by Gregory McFarquhar. Both students gave seminars at the end of the summer based on data made available through the division's participation in two major field programs, TOGA COARE and BOREAS. Marr's presentation was entitled "Carbon Exchange in Northern Forests;" Nash's presentation was entitled "The Use of TOGA COARE 2D Probe Data to Better Understand the Possible Causes of the High Albedos of Tropical Cirrus."
Several division staff and long-term visitors contributed to many non-technical and outreach activities during FY 95. NCAR's Project LEARN (Laboratory Experience in Atmospheric Research at NCAR), a three-year project to explain atmospheric science and demonstrate hands-on teaching methods to middle-school science teachers from four states, is one of these. In addition to Project LEARN, many MMM scientists gave talks for the LASERs (Learning About Science Easily and Readily series), provided interviews with the media, judged and advised students at science fairs, gave presentations in local schools or through NCAR's Education and Tour Program, helped develop curriculum, tutored grade school and high school students in the Boulder area, and taught health-related classes for UCAR's Wellness Committee. Some of the staff and visitors who were engaged in these activities during FY 95 were Daniel Breed, Roelof Bruintjes (joint appointment with RAP), Richard Carbone, William Cooper (joint appointment with ATD), K. Davis, Janine Goldstein, Andrew Heymsfield, Robert Kerr, Charles Knight, John Latham (visitor, University of Manchester Institute of Science and Technology, England), Margaret LeMone, Piotr Smolarkiewicz, and Trier.
On 22 April 1995 NCAR celebrated its 35th anniversity with an Open House which was held at the Mesa Laboratory, Foothills Laboratory, and Research Aviation Facility (Jefferson County Airport, Broomfield) sites. The MMM Division participated in this open house with its own exhibit entitled "Research on Regional Weather." This exhibit featured displays on visualizing scientific data, forecasting local weather, exploring downslope winds, and capturing ice crystals. Several MMM staff and visitors participated in the preparation of the displays and the tours during the full-day event including Steven Aulenbach, Toni Biter, William Boyd, Breed, Chen, Clark, Janice Coen, C. Davis, Goldstein, Hall, Josephine Hansen, Heymsfield, Hsiao-Ming Hsu (visitor, Woods Hole, MA, joint appointment with RAP), Sudie Kelly, Klemp, C. Knight, Manning, Larry Miloshevich, Kathleen Morgan, Jon Nelson (visitor, University of Colorado), Mary Ann O'Meara, Jody Tanner, Patricia Waukau, and Weisman.