IBM demonstrates Deep Thunder
at the American Meteorological Society 2000 conference
The capabilities developed and utilized over the last
three years in various venues were employed at the American Meteorological
Society 2000 Conference (AMS 2000: January 9 - 15, 2000 in Long Beach,
CA) in the IBM booth as part of the conference's technical exhibition.
The system was adapted to the Long Beach area.
For only the second time, "nested" forecasts at 16, 4
and 1 km resolution (areas of 976x976, 244x244 and 61x61 km in size, respectively)
were produced. This time, they were centered over Long Beach (specifically
at the Convention Center). They will be tied to multi-resolution
visualizations to make live predictions during the conference. At
the previous AMS conference, only a single
resolution (8 km over at area 800x800 km in size) was supported.
This new capability is critical for a number of commercial Deep Thunder
applications, where the domain of the forecast is tailored to the geographic
region of interest enabling one to "zoom in" on predictive forecasts.
The system will be running in parallel on eight 200 MHz 2-way POWER3 nodes
for compute and an additional one for I/O. Forty-eight-hour forecasts
required about 8 hours for all three geographic nests. Three workstations
(two IBM RS/6000 43P-260s and an IBM Intellistation M-Pro) and three laptops
(IBM Thinkpads 770Z and 600E and RS/6000 860) will be available to interact
with the model and analyze results. Each of these nests are shown
in the images below. The first image shows the domain of the outer
nest with 1 km-resolution topography data and a number of major cities
marked.
The next two images are from animation sequences of a
24-hour test forecast showing predicated temperature contours and values
at specific sites, and streamlines of surface winds draped over the local
terrain. The images are for 4 pm local time on December 20, 1999
from the forecast from 4 am on December 20 to 4 am on December 21.
The first image is from the 4 km nest. You can see an animation
of this view of the data (or at lower resolution).
Although these images are from runs made before the conference, they illustrate
the domains of the inner two nests.
The next image is from the 1 km nest. You can see an animation
of this view of the data (or at lower resolution).
The performance and resolution enhancements were mapped
to three distinct visualization and analysis applications. In addition
to general improvements, the visualization tools were adapted for multi-resolution
operations via a new method to encapsulate access to nested data.
A 3d facility for interactively browsing model results and tracking the
simulation was used to create the images and animations above, which includes
flyover and time-based animation of various weather variables, and "snapshots"
for web access as PanoramIX scenes, simplified VRML geometry and images.
Two applications for the analysis of the post-processed model output provided
complementary facilities. One was focused on the entire 3d model
domain while the other emphasized surface and upper atmospheric layers.
Details about these visualization applications are available in a paper
for you to read. A paper (3.1.2)
on the visualization portion of the work was presented in the Interactive
and Information Processing System conference during the AMS meeting.
Due to a number of logistical difficulties, raw observations
and access to data assimilation via LAPS for the pre-processor step were
unavailable at AMS. Therefore, RAMS was initialized with the results
from the ETA synoptic scale model from NCEP, which are computed at 32 km
resolution, but sampled at 40 km for public availability. These same
data were also used for boundary conditions for the model. Since
this model is run only twice per day, two Deep Thunder runs were
completed each day of the conference.
The results from one run during the conference is shown
below produced by the browser application. The image illustrates
cloud properties and surface temperature and winds at 4 am on January 12,
2000. It shows a terrain map, pseudo-colored by contours of predicted
surface temperature overlaid with coastline, national boundary, state,
county and river maps. Some major cities in the area are also marked
with predicted temperatures. Forecast winds are illustrated by arrows
show the wind direction, which are, colored by speed. Clouds are
visualized as a white, translucent isosurface of cloud water density.
This image combines the 4 and 1km nests into an integrated view.
An animation of this 48-hour forecast
shows how the model picks up the sea breeze along the coast, for example.
To evaluate these model results, it is useful to compare
them to actual observations as well as
other model results.
lloydt@watson.ibm.com
Last updated January 11, 2001
