Web+tools+approach

Web resources to do the homework Ingrid or PSD or Climate Explorer

=__** International Research Institute (IRI) Ingrid: **__= =Found here: [|Climate Library / Ingrid]=
 * DESCRIPTION**: Ingrid, formerly known as "fast-grid", is an online functionality that supports data analysis and visualization. Ingrid input is based on the IRI Climate Library system that contains virtually any climate related dataset that you can imagine (air, land, sea, ice, space, etc...). Plus, Ingrid can output information through custom plot creation or data download in many formats (binary, NetCDF, ASCII, etc...).


 * STEP ONE**: Locate data using the Climate Library. Data can be found through one of 5 methods: browse dataset, browse maproom, by category (Historical Model Simulations--where NCAR/NCEP Reanalysis lives), by source (NASA --where TRMM lives), by search (type in any query -- MODIS NDVI). These options are located on the home page (link above) along the left column under the Finding Datasets section. Let's do a simple example to produce a plot of monthly climatology of zonally averaged global 925 hPa zonal wind using the the NCEP/NCAR Reanalysis data. Since we are averaging in the x dimension (longitude) we should expect a latitude vs. time plot.

Locate data by clicking on the By Category selection mentioned above. ( Of course, you could locate this data through other methods as well...) Then proceed to select the following links in the order below. You will now have advanced to a screen that looks like the one below. It describes the data that has been accessed by you from the Climate Library from the above sequences. Now, you will want to specify the dimensions of interest in the x,y,z,and t dimensions. Remember that we are aiming to a globally averaged plot, so we will not change the x and y dimensions. However, we did specify the 925hPa level, so we will want to be sure to specify that level in the z dimension. All of the dimension settings are done in the ** Data Selection **section (located near the top of the page).
 * By Category ** --> ** Historical Model Simulations **--> ** NOAA NCEP-NCAR CDAS-1 ** --> ** MONTHLY ** --> ** intrinsic ** --> ** pressure level **--> ** zonal wind **



//link for the page above//**: []** Selecting the "** Data Selection **" link on the above screen will bring you to the following screen:
 * STEP TWO:** Data dimension selection.



Now what we want to do is to isolate the range dimensions (located in the smaller grey box above) to meet our criteria. Following our example in this case, we change P to only have the value 925. Once that is done, then select the "Restrict Ranges" box just below. Once that is complete, then select the "Stop Selecting" option at the bottom of the larger grey box. Now, you have a screen that looks like this one below. It is almost identical except in the fact that the Pressure dimension has been reduced from 17 levels to one (925hPa).



At this point you are ready to do a few things. You can: 1. apply an operation to the data (adding values, averaging dimensions, calculate "stuff", etc...) This can be done in the ** Filters ** (point and click) link above or via the ** Expert Mode **with hand written text. ** Expert Mode **relies on knowledge of Ingrid commands that can be quickly learned through the tutorials / documentation section located on the left blue column. You can also find examples from performing a simple web search for "IRI Ingrid functions." Everything here is intuitive so explore both options! 2. produce a plot (which then takes you to the ** Views ** page) Plots can then be customized in terms of font, zooming in/out, color scales, value ranges, etc... 3. download data in various formats including, but not limited to: GeoTIFF, binary, NetCDF, ASCII, OpenDAP....

For this example, we will perform a simple operation to make a zonal average and then produce the plot and download the image. You can explore how to download the data itself on your own. It takes seconds.

From the screen above, click on the ** Filters ** link on the upper right section. You are then taken to a screen like the one below:



Since we want a zonal average, we will now select the "Average over ** X **" option. Voila! A zonal average of our data has been done. Now take a second to view the Ingrid commands that produced the operation. Once you select the "Average over ** X **" option you will then be taken back to the previous screen. Now, select the ** Expert Mode ** link. A familiar screen pops up, but with a dialog box where actual Ingrid commands are entered. Of course you can always enter them by hand from the beginning or performing the point and click method described above does the same.



Greater detail of the screen above can be viewed here: []

From the Expert Mode you can see how easy it would be to select meriodional wind instead of zonal. Simply delete the .u after .PressureLevel and replace it with a .v EASY! Or, what if you wanted a meridional average instead of a zonal? Of course, just substitute [Y]average for [X]average. What about altering your desired pressure level? You get the point by now... Without making any changes, click " ** Views ** ." On the other hand if you make changes, be sure to click "ok" and then Views.



This is where the beauty begins.Above is an interactive plotting window where you can modify plot size, font, etc. You can also change the axis display. If you prefer latitude on the y-axis and time on the x-axis you can adjust those via the pull down menus. Again, this is all intuitive so explore a little. If you scroll down (sorry it got chopped in my screen capture) you will notice options to export the plot in multiple formats, export the data in the plot, edit the plot with additional features (like colors).You can display colors and contours via the pull down menu below the colorbar. You can also zoom into different section of the plot by using the blue buttons to the left of the plot. Be sure to experiement with each option. You will be surprised at what it can do. To go directly to this page click here: []

From the above screen, I made this image in less than 20 seconds. Can you guess what was done and how I did it?

ANSWER: I adjusted the time to begin at 1 Jan 2008 and end at 30 Jan 2010 by manually adjusting the time dimension boxes to the far left. I then changed the axis from the drop down menus so that time is on the horizontal axis and latitude is on the y-axis. Next, I selected the colors | contours option from the pull down menu below the colorbar. Finally, I selected to download the image as a JPEG.

Don't forget to familiarize yourself with the Ingrid Functions and tutorials to see what all it can do.