ISIS tutorial Project NSF IPY: Admunsen Sea Embayment IPY Project Team: Jesse Johnson, Christina Hulbe, Joel Henry, Martin Barett, Slawek Tulaczyk Dacian Deascu, Cheryl Seals Tutorial Created by Auburn University Computer Human Interaction Laboratory 2008 Cheryl Seals Ravikant Agarwal Feng Wu Sreekant Bogo Vasavi Chilimantula Jie Bao CHIL
The International Polar Year is a large scientific programme focused on the Arctic and the Antarctic from March 2007 to March 2009. IPY, organized through the International Council for Science (ICSU) and the World Meteorological Organization (WMO), is actually the fourth polar year, following those in 1882-3, 1932-3, and 1957-8. In order to have full and equal coverage of both the Arctic and the Antarctic, IPY 2007-8 covers two full annual cycles from March 2007 to March 2009 and will involve over 200 projects, with thousands of scientists from over 60 nations examining a wide range of physical, biological and social research topics. It is also an unprecedented opportunity to demonstrate, follow, and get involved with, cutting edge science in real-time. IPY
GLIMMERis a set of libraries, utilities and example climate drivers used to simulate ice sheet evolution. At its core, it implements the standard, shallow-ice representation of ice sheet dynamics. This approach to ice sheet modeling is well-established, as are the numerical methods used. What is innovative about GLIMMER is its design, which is motivated by the desire to create an ice modeling system which is easy to interface to a wide variety of climate models, without the user having to have a detailed knowledge of its inner workings. This is achieved by several means, including the provision of a well-defined code interface to the model, as well as the adoption of a very modular design. The model is coded almost entirely in standards-compliment Fortran 95, and extensive use is made of the advances features of that language. GLIMMER
The Interactive System for Ice Sheet Modeling (ISIS) is a user interface to GLIMMER. It is still in development, as part of an International Polar Year collaboration among groups at the University of Montana, Portland State, UC Santa Cruz, Auburn, and the University of Texas at El Paso. ISIS
Getting Started with ISIS First step is to Select File ->Select Scenario
Getting Started with ISIS Next step : select Greeland
Choose the Scenario (e.g. Greenland) you want and press OK Right side is the introduction of the scenario you selected
An example of setting window(in red rectangle ) After finish your settings go to Execution Tab
An example of setting window cont. If you enter an error file name the tree will turn red
Press Start Glimmer to start Glimmer Wait a minute … until it is finished
Next select Visualization Tab Select the variables you want in the red highlighted Variables section Press the play button to begin
Check the attribute of any variables in metadata box Now you know variables name of “thk” is: ice thickness Its units is meter.
You can also choose another variable to see its visualization Select another choice from the Variables section Also you can select another input file in the section highlighted below
You can move the picture and zoom it. It is selected with the mouse.
To view the value of variable corresponding to a particular color, you can drag the pointer pointed by the RED arrow.
If your output file contain a variable named:ivol You can go to the Analysis tab to see the sea level change
You can use the feature below to enhance the visualization : • Save as image • Save the picture into image file. • Change Colormap • Specify colormap for better visualize output • Enable interpolation • interpolate the output image make it more smooth. • Show contours • Shows contours where it has • Show axes • Display axes of the image Visualization enhancer– Display Options Select Display Options
Configuration Tab –How to If you want more specific input/output of your ISIS You need to configure ISIS by yourself
When you select different model, the configure tree will change correspond with it : • EIS CONY • EIS ELA • EIS Temperature; • EIS SLC • EISMINT-1 Fixed margin • EISMINT-1 Fixed margin • EISMINT-1 moving margin • EISMINT-1 moving margin • EISMINT-2 • EISMINT-2 • EISMINT-3 • EISMINT-3 Configuration Tab – Model Specific the EIS driver to be used. Five driver models list below: EIS CONY,EISMINT-1,EISMINT-2,EISMINT-3
EIS CONY • EIS ELA • EIS Temperature; • EIS SLC Configuration Tab – Model: EIS CONY • ela file: name of file containing ELA variation with time • ela ew: name of file containing longitudinal variations of ELA field. • ela a: ELA factor a • ela b: ELA factor b • ela c: ELA factor c • zmax mar: The elevation at which the maximum mass balance is reached • bmax mar :The maximum mass balance, • zmax cont: The elevation at which the maximum mass balance is reached • bmax cont: The maximum mass balance
temp file: • name of file containing temperature forcing time series • type: • 0 polynomial • 1 exponential • lapse rate: • lapse rate Configuration Tab – Model: EIS CONY • slc file: • name of file containing sea–level change time series.
period : • period of time–dependent forcing (switched off when set to 0) Configuration Tab – Model: EISMINT-1 fixed margin&moving margin • temperature : • Temperature forcing • massbalance : • Mass balance forcing • period : • period of time–dependent forcing (switched off when set to 0)
temperature : • Temperature forcing • massbalance : • Mass balance forcing Configuration Tab – Model: EISMINT-2 & EISMINT-3
ewn: • number of nodes in x–direction • nsn: • number of nodes in y–direction • upn: • number of nodes in z–direction • dew : • node spacing in x–direction (m) • dns : • node spacing in y–direction (m) • sigma file : • Name of file containing coordinates. Alternatively,the sigma levels may be specified using the [sigma]section decribed below. Configuration Tab – grid Define model grid
tstart: • Start time of the model in years • tend: • End time of the model in years • dt: • size of time step in years • ntem: • time step multiplier setting the ice temperature update interval • nvel: • time step multiplier setting the velocity update interval Configuration Tab – time Configure time steps, etc.
sigma levels : • sigma levels (real) list of sigma levels, in ascending order, separated by spaces. These run between 0.0 and 1.0 Configuration Tab – sigma Defines the sigma levels used in the vertical discretization
ioparams: • name of file containing netCDF I/O configuration. • temperature: • 0 isothermal • 1 full • flow law: • 0 Patterson and Budd • 1 Patterson and Budd (temp=-10degC) • 2 const • basal water: • 0 local water balance • 1 local water • 2 none • marine margin: • 0 ignore marine margin • 1 Set thickness to zero if floating • 2 Set thickness to zero if relaxed bedrock is below a given depth • 3 Lose fraction of ice when edge cell • 4 Set thickness to zero if present-day bedrock is below a given depth Configuration Tab – options Determine how various components of ice sheet model are treated
slip coeff • 0 zero • 1 set to a non–zero constant everywhere • 2 set constant where the ice base is melting • evolution • 0 pseudo-diffusion • 1 ADI scheme • 2 diffusion • vertical integration • 0 standard • 1 obey upper BC • topo is relaxed • 0 relaxed topography is read from a separate variable • 1 first time slice of input topography is assumed to be relaxed • 2 first time slice of input topography is assumed to be in isostatic equilibrium with ice thickness. • periodic ew • 0 switched off • 1 periodic lateral EW boundary conditions (i.e. run modelon torus) • hotstart • hotstart the model if set to 1 Configuration Tab – options Determine how various components of ice sheet model are treated
log level: • set to a value between 0, no messages, and 6, all messages are displayed to stdout. • ice limit: • below this limit ice is only accumulated; ice dynamicsare switched on once the ice thickness is above this value. • marine limit: • all ice is assumed lost once water depths reach thisvalue • calving fraction: • fraction of ice lost due to calving. • Geothermal: • constant geothermal heat flux. • flow factor: • the flow law is enhanced with this factor • hydro time: • basal hydrology time constant • isos time: • isostasy time constant • basal tract const constant: • basal traction parameter. • basal tract: • basal traction factors. Configuration Tab – parameters Some parameters for ISIS
lithosphere: • 0 local lithosphere, equilibrium bedrock depression is found using Archimedes’ principle • 1 elastic lithosphere, flexural rigidity is taken into account • Asthenosphere: • 0 fluid mantle, isostatic adjustment happens instantaneously • 1 relaxing mantle, mantle is approximated by a half-space • relaxed tau: • characteristic time constant of relaxing mantle • Update: • lithosphere update period Configuration Tab – isostasy Options for Isostasy model
flexural rigidity: • flexural rigidity of the lithosphere (default:0.24e25) • num_dim: • can be either 1 for 1D calculations or 3 for 3D calculations. • nlayer: • number of vertical layers (default: 20). • surft: • initial surface temperature (default 2°C). • rock_base: • depth below sea-level at which geothermal heat gradient is • applied (default: -5000m). • numt: • number time steps for spinning up GTHF calculations (default:0). • rho: • The density of lithosphere • shc: • specific heat capcity of lithosphere • con: • thermal conductivity of lithosphere Configuration Tab – elastic lithosphere & GTHF Settings on Lithosphere elastic, temperature and geothermal heat
title: • Title of the experiment • institution: • Institution at which the experiment was run • references: • references that might be useful • comment: • a comment, further describing the experiment Configuration Tab –CF defaul This section contains metadata describing the experiment.
name: • The name of the netCDF file to be read. Typically netCDF files end with .nc. • time: • The time slice to be read from the netCDF file. The first time slice is read by default. Configuration Tab –CF input Any number of input files can be specified. They are processed in the order they occur inthe configuration file.
name: • The name of the output netCDF file. Typically netCDF files end with .nc. • Start: • Start writing to file when this time is reached (default: first time slice). • Stop: • Stop writin to file when this time is reached (default: last time slice). • Frequency: • The time interval in years, determining how often selected variables are written to file. • variables: • List of variables to be written to file. Names should be separated by at least one space. The variablenames are case sensitive. Variable hot selects all variables necessary for a hotstart. Configuration Tab –CF output Specify output NETCDF file and output variables for each file Also the frequency of output
Configuration Tab –Save File use File->Save to save your configure into test.config So your configuration will take effect next run of glimmer