CISM Model Development Roadmap

Transcription

1 CISM Model Development Roadmap Overview of Model Development Approach CISM s research goal is to develop a comprehensive suite of physics-based numerical simulation models that describes the space environment from the Sun to the Earth. Our strategy is to build the comprehensive model out of separate component models of parts of the overall system, and to couple these together using a computational framework. In addition to developing and coupling the physics-based models, CISM also uses empirical models. The empirical models serve two purposes: to provide well-defined baselines against which the developing physics-based models can be assessed, and to make quickly available a set of forecast models (i.e., models that can be run using real-time inputs to yield results in advance of the outcome, for forecast or nowcast purposes). Development began by using ad hoc methods to couple a core set of existing MHD and neutral fluid models, covering the regions from the solar corona to the thermosphere. Figure 1 illustrates the two tracks of initial models: the core physics-based MHD models (blue), and empirical or hybrid empirical/physics-based models (yellow). Acronyms are defined at the back of this document. Figure 1 Succeeding versions of the coupled models build upon this initial set by providing improvements through parallel development in several areas, as indicated schematically in Figure 2. New generations of component models add and/or improve physics, increase computational efficiency, provide higher resolution, and refine the coupling interfaces. Sophisticated modular coupling, using the InterComm and Overture technologies, replaces ad hoc coupling to create a framework with a robust interface for model additions and replacements. These coupling technologies provide the computational capabilities needed for efficiently running the coupled models and representing the physical processes by which the modeled regions interact. This includes a communications channel between parallel programs in coupled model runs across a

2 variety of platforms, support for overlapping grids, and a powerful syntax for arithmetic and differential operations. New component models are introduced to add physics and capability through varying degrees of interaction with the core models. Examples include: the Rice Convection Model (RCM) that is tightly two-way coupled with the core models; the Solar Energetic Particle (SEP) and Radiation Belt models that operate within the environment defined by the comprehensive MHD model; and a variety of auxiliary models that use the comprehensive model as the foundation for calculations tailored to specific user needs. Examples of such tailored models include using the CMIT current systems to calculate localized db/dt on the ground and a global Ap index (e.g. for SEC), and using the CMIT ionospheric profiles to calculate turbulence growth for prediction of scintillations (in partnership with AFRL). Figure 2 As development proceeds, the modular nature of the model suite provides the flexibility to construct a variety of model combinations, and to use in situ measurement data at various points as model drivers and for direct comparison with model data. Figure 3 illustrates several alternative configurations, including: the comprehensive physicsbased model (CORHEL and LTR); a hybrid model formed by substituting WSA for CORHEL or by the substituting the coronal portion of WSA for MAS; and the use of L1 satellite data to drive the stand-alone LTR geospace model or to compare with results from the standalone CORHEL. Similarly the original forecast model chain can incorporate new physics-based components, for example the Enlil model can replace the solar wind portion of WSA.

3 MODEL CONNECTIVITY & OPTIONS Figure 3 Model Development Sequence The following tables summarize the sequence of CISM model development through Year-5. The Year 6-10 sequence is outlined the CISM Model Development Timeline, which is maintained on the web

4 Year Model Components Capabilities & Additions I. Solar-heliosphere coupled physics-based models CORHEL 1.0 MAS Global ambient (non-event) solar wind specification (including points of ENLIL particular interest, e.g., L1). Inputs: filtered NSO/KP synoptic maps of photospheric magnetic field from specified Carrington rotation. Ad hoc coupling. Frozen Devel CORHEL 1.2 Version of CORHEL 1 frozen for formal validation. Frozen, tagged pre-val CORHEL 2.0 Add: Additional observatory (Wilcox) for inputs, giving greater data Frozen availability and ability to compare and verify input fidelity. Magnetograms can be visually preprocessed. Broader range of controllable inputs. Web-bsaed GUI interface. Stand-alone CD with Linux executables CORHEL 2.3a Version of CORHEL 2 frozen for formal validation. Frozen, tagged pre-val CORHEL 3.0 Add: Full set of observatories as inputs (NSO/KP, Wilcox, Mt. Wilson, Frozen, tagged 2006 MDI). Cone model incorporated for ICME propagation and SEP shock pre-val. source CORHEL 3.4 Minor updates; fixes insertion-time of heliospheric transients. Frozen, taggedd pre-valid II. Solar-heliosphere other physics-based models Cone Model Interim model of CME-like ejection for propagation in a solar wind model (e.g. CORHEL) to produce shocks and background fields for SEP model version 1.0 and to predict the timing and geometry of an ICME in the realistically modeled interplanetary medium. Does not model internal magnetic fields of ICME. Inputs: Source location, angular extent, and speed (observables), density and temperature. To be incorporated in CORHEL 3.0 and SW Event- Driven forecast model. Delivery MAS at CCMC. Enlil at CCMC. To CCMC in 2005, w/out GUI. To CCMC Apr PFSS Coronal magnetic field driven by magnetograms. At CCMC WSA Baseline Same version as running at SEC in Forcing only NSO/KP input. Baseline model for several validation skill scores. Frozen, tagged pre-val SEPMOD 1.0 Energetic particles from parameterized shock source, using shocks and fields from cone model ICME initialization in CORHEL (postprocessing) WSA-ENLIL WSA ENLIL Forecast capability using quasi-realtime magnetogram acquisition and runs. Shock-Finder in test with Cone Model outputs. Ad hoc shock source description being iterated. Frozen, tagged prevalid Respository Detail CORHEL-1_2-prevalid CORHEL-2_3a-prevalid CORHEL-3-prevalid Notes Version for formal validation Version for formal validation To CCMC. CORHEL-3.4-prevalid Version for formal validation In transition at SEC, CCMC WSA-2006_01_13-v1_0- prevalid WSA prevalid ENLIL-wsa-2.4-prevalid See also VI. "WSA Forecast" model Currently uses jumps along field lines. Will introduce shocknormal jumps. see VI. Solar Wind Ambient Forecast

5 Year Model Components Capabilities & Additions III. Geospace coupled physics-based models CMIT 1.0 LFM Geospace model driven by measured (ACE) or modeled (e.g. CORHEL) TING solar wind parameters at L1. Two-way ad hoc coupling. LFM with OMP parallelization. Imposed auroral and empirical low-latitude potentials CMIT 1.1 LFM TING 2007 CMIT 2.0 LFM TIE-GCM 2005 LTR 1.0 CMIT 1.0 RCM 2005 Add: Neutral wind feedback from ionosphere to magnetosphere. Add: Two-way coupled, TIE-GCM (MPI parallelization) replaces TING, giving low latitude electric field. Modularized LFM & TIE-GCM with InterComm. LFM two-way coupled to both RCM and TING. (RCM + CMIT 1.1). RCM drifts give accurate pressure and density to LFM; LFM gives plasma boundary conditions and magnetic field for RCM. Coupled model provides Region 2 currents and penetration electric fields. IV. Geospace other physics-based models Radiation Belt 3 component models for energetic particles in earth's magnetosphere: 2D Models Radbelt, 3D Radbelt, SEP Cutoff. Common future development includes 2D Radbelt 3D Radbelt SEP Cutoff parallelization, cubic interpolation, and InterComm. Efficient tracking of 2D guiding center motion w/ large number of particles in time-dependent LFM fields; polar grid. Post-processing gives fluxes. Future additions: cartesian grid, interior B model. 3D trajectories w/ choice of either guiding-center or Lorentz calculation in time-dependent LFM fields; cartesian grid. Future additions: interior B model; flux calculation. Full 3D Lorentz trajectories determine SEP cutoffs in time-independent LFM fields; cartesian grid. Next: add interior B. Devel. Frozen. Pre-val distribution available. Models coupled. Diagnostics ongoing. v. 1.0 frozen; tagged preval. Tagged devel, development ongoing. Devel version frozen. Tag for validation after adding interior B. Delivery Pre-val distrib to CCMC Jan 2006 v1.0r3 at CCMC Mar 2007 Research model. Not for external delivery. Respository Detail CMIT-1.0-prevalid-r2.tgz CMIT-1.0-prevalid-r3.tgz rbelt2d-1_0-prevalid rbelt3d-1_0-devel Notes All pre-mpi CMITs require at least a 4- processor, shared memory computer. v1.0r3 provides Linux platform compatibility, improved test suite. Neutral wind feedback incorporated in CMIT 2.0 RCM-LFM diagnostics underway; tests w/ parallel LFM at high resol.

6 Year Model Components Capabilities & Additions V. Comprehensive physics-based models CISM 1.0 CORHEL 1.2 Ad hoc coupled CORHEL and CMIT. CMIT 1.0 Provides solar wind and geospace properties. Inputs: same as CORHEL CISM 2.0 CORHEL 3.0 CMIT 2.0 L1 Coupler SEPMOD 1.0 Automated coupler added Adds improvement to component models described above. VI. Forecast and special-purpose models MeV Electron Empirical model: MeV electron radiation belt flux L= Forecast Added: flux at 6 energies Devel. Frozen for validation. in test Delivery Devel. Envir. Respository Detail CISM_DX-Release-0_24 Notes Vassiliades ARMA or FIR. Not currently targeting formal SEC test product Ap Forecast Empirical model: daily average Ap index with lead time of 1-7 days. Inputs: L1 SW velocity and recent Ap history Ap Forecast 3-Hr Adds 3-hr running-average ap with 24-hr derived Ap, per SEC evaluation of daily model. (SEC Goal #1 set Jan. ) 2005 Geomagnetic Disturbances; Empirical 2007 Geomagnetic Disturbances; Physics-Based WSA Forecast Model Auxiliary calculations from CMIT data. Predicted regional ground magnetic variations, driven by solar wind parameters. This Weigel-Baker model is the baseline empirical model for geomagnetic disturbances. Regional ground magnetic variations calculated from model currents, initially CMIT 2.0. Global Ap calculation as top-level indicator for comparison and assessment of model confidence. (SEC Goal #3 set Jan. 2006) Empirical solar wind model. Driven by Mount Wilson, NSO/KP, and Wilcox observatory data. Released Development complete. Running in realtime. Complete In development. Devel. Envir. Devel Envir. Running in real time in SEC Devel. Envir. To CCMC in CISM_DX-Release-0_24 SEC Goal 1 of Jan Weigel SEC Goal 3 of Jan See also II. WSA Baseline model WSA Complete At SEC, CCMC. Running CCMC in realtime. WSA prevalid 2006 Solar Wind Ambient Forecast Model WSA+ENLIL Daily updated magnetograms from NSO/KP drive coronal portion of WSA model, which drives ENLIL MHD Solar Wind model to provide ambient SW in the heliosphere and at L1. Purposes: (a) Research model demonstrates insertion of physics-based MHD module into forecast model and investigates sensitivity of solar wind models at L1 to inner boundary conditions. (b) Forecast model. (SEC Goal #2 set Jan. 2006) Complete. Devel. Envir. WSA prevalid ENLIL-wsa-2.4-prevalid SEC Goal 2 of Jan Runs on workstation. See also II. WSA- ENLIL

7 Names & acronyms CISM CMIT CORHEL ENLIL InterComm LFM LTR MAS Overture SEP TIE-GCM TING WSA Center for Integrated Space Weather Modeling Coupled Magnetosphere, Ionosphere, Thermosphere model. Coupled CORona (MAS) HELiopsphere (Enlil) model Heliosphere model (Enlil is the Sumerian god of wind) Software package used in model coupling to provide communications & control between parallel (and serial) programs Lyon, Fedder, Mobarry magnetosphere model Coupled LFM, TIE-GCM, RCM geospace model Magnetohydrodynamics Around a Sphere coronal MHD model Software package used in model coupling to handle overlapping grids; computations between domains Solar Energetic Particle model Thermosphere Ionosphere Electrodynamics General Circulation Model Thermosphere Ionosphere Nested Grid model Wang-Sheeley-Arge model WSA in CISM is supported through a partnership with AFRL