ATM350 Week 3

Tuesday, Feb. 4, 2014

This week, you will do some more work with IDV. You will make it so your IDV sessions will always have USA state boundaries, as well as Canadian provinces and Mexican states) drawn on the map when you open IDV. Then you will create a variety of products, including:

1. A 24-hour loop of surface observations

2. A map of RAOB observations at 850 hPa (mb)

3. A visible satellite image

4. A loop of forecast 850 hPa height and temperature from the NCEP's NAM model

5. A national radar reflectivity composite

6. A Skew-T based on an Albany, NY RAOB

The first two highlighted products are what's on tap for today.

Screen shots will guide you on the way! Have fun! Please feel free to pair up as you work on the exercise, but be sure each of you has the chance to complete the exercise! You will "publish" each product to your directory on our RAMADDA server, so we'll be checking to see that this has been done by all of you!

Now, let's make some maps!!

TASK 1: Standardize your IDV's maps upon startup of IDV

Open up a terminal prompt on one of the Maproom's workstations (be sure you have logged into the machine while it is running Linux/CentOS, not Windows). Then type "idv" to launch the IDV. As usual, you will see two windows; a Dashboard window and a Map View window:

If you see a Help Tips window as well, close it out (and uncheck the box saying "Show tips on startup" if you wish).

Now, let's work in the Map View window to add state and provincial outlines to our map:

The right-hand side of the Map View window is the Legend frame. Here you can manipulate aspects of each layer that appears on the map to the left of the Legend frame. Just as you would in a web page, click on the Default Background Maps link:

Click "on" two maps: the North & Central America one and also the Hi-Res US one.

Go back to your Map View window and your map should now look like this:

Let's make it so these maps will always appear when we first launch the IDV. As you did before, in the Legend frame, click on the Default Background Maps link:

Now, exit out of the IDV.

Relaunch the IDV. Does your Map View window show the state and provincial boundaries now? If not, go back and try again!

TASK 2: 24-hour loop of surface observations (METARs)

Here we will generate a loop of the most recent 24 hours of METAR observations, plotted on a map centered over New York State.

Open the IDV if you haven't already. As we saw last week in class, by default the IDV will choose a view window that covers the entire domain where the data source you choose encompasses. For METAR observations, this is the entire world. For this task, we want to restrict our view to just New York State and vicinity. To do this, in the Map View window, click on the Projection menu and toggle off the Auto Set Projection setting:

Once you highlight the Auto-set Projection setting, the checkmark will disappear. Next, we will load one of the predefined IDV map projections so the view region includes a smaller area, but centered over the Empire State.

"Dig down" through the Projection menu until you find New York State:

The white "Wireframe Box" is useful mostly when we manipulate three-dimensional volumes in IDV, which we will not deal with yet. The appearance of this box is a configurable option in the User Preferences section of the IDV, so let's turn it off: in the top-level menu of either the Map View or Dashboard panes, select Edit and then mouse down to Preferences:

The User Preferences window opens. Click on the View tab. Toggle off the Show Wireframe Box setting by clicking on the checkbox to its left. Then click on the OK button to close this window.

You should see that the wireframe box is gone (but you could of course make it visible again by just toggling on its setting using the exact same procedure)!

Now direct your attention to the other main IDV window, the Dashboard. If you have a hard time finding the window on your desktop, you can always make it jump to the front by clicking on the little icon that looks like a gamepad, which appears right underneath the top-level File menu in your Map View pane. In the Dashboard, we will load METAR data similarly to how we did it last week.

Looking at the 2^nd menu from the top (i.e., the Quicklinks—Data Choosers—Field Selector—Displays menu), click on Data Choosers. In the left-hand frame, highlight the Point option directly underneath the Observations header (if you don't see it underneath Observations, click on the arrow to the left of Observations to revael the list of options). In the main frame, click on the Surface tab, select adde.ucar.edu and Surface (METAR) Data as the data server and data type options, and click on Connect. Select the Relative tab. Assuming you have an active internet connection, the previously inactive (grey) list of relative times should turn active (black). Scroll down until you see and select 24 most recent. Be sure Increment is set to 1.0 hour and that the Create display box is checked. Then click on Add Source.

While the data loads, you will see the Field Selector tab activate and its window appear:

Depending on how fast the data loads, eventually the Map View will pop back into view, and you should see METAR obs plotted over a region centered over New York State (if you see the whole world, you probably forgot to turn off Auto-set Projection, and if you see a CONUS-centered map, you neglected to select New York as the map projection). You should see the earliest time in the loop plotted:

This first frame appears as the dark blue box in the Animation control part of the Map View window, located above the map and just to the left of the Legend frame. All the other available frames (squint a bit and you should count 24 of them) appear in green. Press the single right arrow Play button and watch your animation unfold! Press it again to stop the animation.

Now let's save your hard work as an IDV Bundle, both to disk and to your directory on the RAMADDA server. Click on File and select Save As. Navigate to your /spare11/atm350/<userid>/idv directory (you will likely need to move up in the directory "tree" to the top, or "root" level of the file system, denoted by a single "/", and then dig back down within spare11). To also "publish" your bundle to RAMADDA, click on Select Publisher, scroll down, and select our DAES RAMADDA Server, which you should be "connected" to. Then click Save:

If you don't see the Select Publisher option, you never installed the IDV RAMADDA Publisher plugin. Go back to last week's exercise and do it! Otherwise, another window will pop up. You should add a brief description, and you can enter METAR as a Tag. Next, select the Parent Folder. Navigate to your folder within the ATM350 folder on our RAMADDA Server:

You should then receive the happy message that your publication was successful!

The next time you, or anyone else, loads this IDV Bundle, it will always be up-to-date, as you requested the 24 most recent hours of METARs. If you had chosen an Absolute time as opposed to Relative, it would remain fixed to the original 24-hour period you chose (and would continue to function only as long as the data remained on the adde.ucar.edu data server).

Now let's reach for the sky, and plot an upper-air map based on real-time RAOB data.

Task 3: Plot a loop of observations from RAOB sites at the 850 hPa level

If you exited out of IDV, load it back up again. If you are continuing along from the previous task, clear out your previous maps and the data that went into them, by going to EditàRemove All Displays and Data:

You should now see a blank map, still centered over NYS, and with no animation frames or controls:

We now want to reset our map projection back to the CONUS. Go to the Projections menu and select CONUS. Also be sure that Auto-Set projection is unchecked (by default, each time you start the IDV, it will be reset to the checked state).

Your map should then show the CONUS at its center. Now once again return to the Dashboard window and choose Point.

This time, click on the Upper Air tab. Leave the default data server and data type as they are (adde.ucar.edu, Upper Air Data), and click on Connect. Select the 2 most recent times under the Relative tab. Select the 850 hPa level, and be sure that the 00 & 12Z only and Create display boxes are checked.

Click on the Add Source button. You should see a two-frame loop of 850 hPa data on the map:

Now, how about we zoom in a bit so the CONUS fills more of the screen. Either slide your mouse scroll wheel forward, or click on the zoom in button using the icon that looks like a magnifying glass with a green + sign to the left of the map.

Check the second time in the animation loop as well. Then, when you are satisfied, save your loop as a bundle named 850hPaRAOBCONUS and publish it to RAMADDA just as you did for your METAR loop.

That's it for today! Thursday you will make the rest of the products listed at the front of this document ... stand by for more instructions!

Let us know your progress and problems you encounter ... just email Ross and Kevin!