NEW ORLEANS -- Republican control of the Senate means that one the most fanatical climate change deniers in Congress, Sen. Ted Cruz (R-Texas), is now in line to head the Senate subcommittee that oversees science funding. This is not good news for supercomputing.
In scientific research, climate change is one of the most demanding applications, both in terms of processing power and data production. Scientists create global atmospheric models, study the chemistry and physics and from this can determine how the Earth's climate is changing and mankind's influence on it.
Supercomputers may well be the best tool in the toolbox for understanding climate change. This type of research takes a big system, and last week NASA took delivery of a new SGI supercomputer, capable of two petaflops. This x86, Linux-based system, with 30,000 cores, replaces a four-year-old, 150 teraflop system. The new system is 18 racks but uses the same amount of power as the older system, while delivering more than eight times the performance.
NASA has long studied the Earth's climate, collecting information from its orbiting satellites and from other worlds, such as the superheated planet Venus and its mainly carbon dioxide atmosphere. Carbon dioxide is the same gas that is being emitted into Earth's atmosphere in larger concentrations.
NASA satellites launched into space are equipped with instruments to examine the Earth, and the climate simulations on the supercomputerr help scientists "make sure those instruments are seeing what we think we should see before they build them," said Daniel Duffy, the high-performance computing lead at the NASA Center for Climate Simulation (NCCS). In other words, the climate simulations help NASA spend its space program money wisely.
It was a NASA scientist, James Hansen, who warned Congress in 1988 about the buildup of carbon dioxide in the atmosphere and the warming planet. Hansen's testimony, which was aided by climate modeling, helped to turn climate change into a national issue.
NASA's effort to study the Earth's climate may be hurt by Cruz, the presumptive head of the Senate Subcommittee on Science and Space, which oversees NASA and the National Science Foundation. Last year, Cruz opposed expanding climate change funding for NASA and wants to concentrate on space exploration.
Cruz's views are based on a denial of climate science, and he told CNN, in an interview earlier this year, that "data are not supporting what the advocates are arguing."
At the annual supercomputing conference, called SC14, climate is a big research area and there are displays throughout the trade show floor of climate models and simulations. Papers are presented on this issue as well.
NASA is developing systems that can model the climate into the future, and a byproduct of that will be a better understanding of future weather and storm forecasting.
"Climate is an extremely hard application to run, and it's lending itself to an exascale system," Duffy said. He added that to understand the climate could easily require a system with as many as 20 million cores.
The highest resolution of NASA computers is now 3.5 kilometers. The resolution, which is analogous to pixel resolution in digital photography, provides more detail in a simulation, but to get the better resolution requires increased supercomputing power. For instance, to simulate the global climate over 10 days takes a full day of compute time to make a forecast. "That's not good enough," Duffy said.
While 3.5-kilometer resolution is good, it's not what's needed for reflecting real-world conditions. What NASA scientists want is to reduce the resolution (the higher the resolution the greater the detail) to 1 kilometer, and even get to as low as a city block.
At that scale, scientists will be able to resolve specific weather events, such as a Midwestern supercells, the innards of hurricanes, and better understand the future of the climate. The new supercomputer, which will be ready to run simulations in early December, will, among the things, be used to study "downscaling" techniques, another term for increasing the resolution of the models.
The supercomputer will also help scientists study the chemistry of the upper atmosphere, the impact of airborne particles called aerosols, and how changes in the planet's surface, such as the shrinkage of the ice caps, increase heat absorption.
There aren't many places that run these complex simulations, and if NASA doesn't run them, then the U.S., and the rest of the world, will need to rely on the scientific information available from other nations, Duffy said.