From The DOE’s “ASCR Discovery”: “High and dry” 

From The DOE’s “ASCR Discovery”


A new supercomputer drought model projects dry times ahead for much of the nation-especially the Midwest.

A detail from a recent map that depicts areas of intensive drought in the West and Midwest. Image courtesy of the North American Drought Monitor.

Midwesterners needn’t bother choosing their poison: droughts or floods. They get a double dose of both.

The region is experiencing what weather experts call a flash drought, says Rao Kotamarthi, who heads climate and earth system science at the DOE’s Argonne National Laboratory near Chicago.

“One of the clearest indicators of climate change is that you get intense periods of precipitation,” he says. The Midwest today can experience intense downpours with drought-like conditions lasting for several weeks in between. “Now some farmers actually have to start irrigating even in northern Illinois, which is a big change from before.”

Kotamarthi’s team published climate-modeling data in Scientific Reports [below] last year that could help U.S. policymakers better anticipate droughts and floods.

Figure 1
June, July, August, and September 2003 PDSI, SPEI (1-month), EDDI, and SDVI_NLDAS (SVDI). The black box represents a Flash Drought area from July 1–September 2, 2003. The USDM index is a weekly index, and dates represent the week ending that date. The SVDI index is a daily index, and the monthly value is averaged for each month. The EDDI index is averaged on the last day of each month for the previous 30 days. The SVDI, PDSI, SPEI, and EDDI plots were generated using the Matplotlib41 library for the Python programming language ( The USDM maps are courtesy of NDMC-UNL and were accessed from The USDM is jointly produced by the National Drought Mitigation Center (NDMC) at the University of Nebraska-Lincoln(UNL), the United States Department of Agriculture, and the National Oceanic and Atmospheric Administration.

The paper expands upon an Argonne-AT&T collaboration that led to a 2019 AT&T white paper, The Road to Climate Resiliency, focusing on the southeastern U.S. AT&T and DOE’s Biological and Environmental Research and Advance Scientific Computing Research programs supported the latest work.

The project also led to release of a Climate Risk and Resilience Portal (ClimRR), developed by Argonne’s Center for Climate Resilience and Decision Science in collaboration with AT&T and the Federal Emergency Management Agency. ClimRR lets users explore future precipitation, temperature and wind for the continental U.S. at high spatial resolution.

There are more than 50 metrics for gauging when a drought occurs – factors such as temperature, precipitation and evapotranspiration. None of them, however, can quickly project drought onset. The Argonne team has established the Standardized Vapor Pressure Deficit drought index (SVDI) to do just that.

“You can calculate vapor pressure deficit with temperature and relative humidity. It doesn’t include precipitation,” says Argonne’s Brandi Gamelin, lead author of the Scientific Reports paper. Instead, it includes a measure of evaporative demand.

“If you have higher evaporative demand, it’s going to pull more moisture out of vegetation and the soil,” drying them, she says. The team also produced a separate wildfire index that is highly correlated to SVDI. In fact, SVDI also works for drought.

Many indices rely on measures of reduced rainfall to define drought. But “We can go months in many California locations without rainfall,” says Gamelin, a native of the state. “It’s difficult to use the same measure in California than you would use, say, in the Midwest related to drought and agriculture or wildfire risk.”

Gamelin compared her new drought index against other available measures and showed that it works just as well.

“Her models gave us confidence that this is a good way to go,” Kotamarthi says. “Vapor pressure deficit is not complicated either to model or measure. One of the things that we push in the paper is how this is useful in the bigger context as climate change increases flash droughts.”

The models forecast climate change at a high spatial resolution, calculating projections for areas measuring 12 square kilometers (4.6 square miles). The team ran the code on supercomputers at the National Energy Scientific Computing Center at The DOE’s Lawrence Berkeley National Laboratory, and at The DOE’s Argonne Leadership Computing Facility.

The team aims to tighten the resolution to four square kilometers (1.5 square miles). That would generate about 4 petabytes of data, the equivalent of 200 billion pages of text.

The goal: help zoom in the global climate model, which operates at a scale of 10,000 square kilometers (3,861 square miles), to 100 square kilometers (38.6 miles) and now to around 16 square kilometers. The simulations focus on extreme and quickly occurring events, generating data at three-hour intervals.

The Scientific Reports paper projected the frequency of droughts that happen once in 10, 25 and 50 years. A 50-year drought, for example, has a 5% chance of happening and would be widespread, affecting the Midwest, Southwest and Northwest. “The areas affected by drought do increase,” Kotamarthi says. “By mid-century, you see larger portions of the Midwest experiencing drought in general.”

Since publishing its drought index, the Argonne team has applied new machine-learning methods to identify both short-term and long-term drought. The team caps projections at 50 years to keep uncertainty values within reasonable limits.

Last year’s study focused on a short-term drought index that worked well, Gamelin says. “Now we’re looking to understand long-term drought better with it.”

A new study will test the index to see if it can identify where and when droughts happened between 1980 and 2021 and probe more deeply into why they began and ended. Then the researchers will apply the methods to projecting future droughts.

Drought can dry the soil but so can wildfire. The heat from wildfires forms a barrier on mountain slopes, resulting in hydrophobic, or water-repellent, soils “so, you have a higher risk or incidence of flash flooding,” Gamelin says. These conditions often lead to droughts and floods happening in tandem. Water flowing downhill also lubricates debris flows, adding to the calamity. “That’s a risk up and down California in the mountains and hills.”

Kotamarthi and Gamelin stress the importance of quantifying uncertainty when considering models of future droughts. “These are projections. They’re not predictions,” Gamelin says.

To calculate uncertainty, the team statistically samples time series and location data 500 times from the Argonne model and three others that are widely used. Each new series then undergoes an extreme value analysis to create a range of minimum and maximum values. The uncertainty figures may help policymakers decide how best to plan for extreme events of varying magnitude.

“Money is not unlimited,” Kotamarthi says. “You may want to make your system resilient to a 50-year drought or a once-a-year drought. We are hoping that this kind of information provides decision-makers some points to think about.”

Scientific Reports

See the full article here.

Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.


Please help promote STEM in your local schools.

Stem Education Coalition

ASCR Discovery is a publication of The U.S. Department of Energy

The United States Department of Energy (DOE) is a cabinet-level department of the United States Government concerned with the United States’ policies regarding energy and safety in handling nuclear material. Its responsibilities include the nation’s nuclear weapons program; nuclear reactor production for the United States Navy; energy conservation; energy-related research; radioactive waste disposal; and domestic energy production. It also directs research in genomics. the Human Genome Project originated in a DOE initiative. DOE sponsors more research in the physical sciences than any other U.S. federal agency, the majority of which is conducted through its system of National Laboratories. The agency is led by the United States Secretary of Energy, and its headquarters are located in Southwest Washington, D.C., on Independence Avenue in the James V. Forrestal Building, named for James Forrestal, as well as in Germantown, Maryland.

Formation and consolidation

In 1942, during World War II, the United States started the Manhattan Project, a project to develop the atomic bomb, under the eye of the U.S. Army Corps of Engineers. After the war in 1946, the Atomic Energy Commission (AEC) was created to control the future of the project. The Atomic Energy Act of 1946 also created the framework for the first National Laboratories. Among other nuclear projects, the AEC produced fabricated uranium fuel cores at locations such as Fernald Feed Materials Production Center in Cincinnati, Ohio. In 1974, the AEC gave way to the Nuclear Regulatory Commission, which was tasked with regulating the nuclear power industry and the Energy Research and Development Administration, which was tasked to manage the nuclear weapon; naval reactor; and energy development programs.

The 1973 oil crisis called attention to the need to consolidate energy policy. On August 4, 1977, President Jimmy Carter signed into law The Department of Energy Organization Act of 1977 (Pub.L. 95–91, 91 Stat. 565, enacted August 4, 1977), which created the Department of Energy. The new agency, which began operations on October 1, 1977, consolidated the Federal Energy Administration; the Energy Research and Development Administration; the Federal Power Commission; and programs of various other agencies. Former Secretary of Defense James Schlesinger, who served under Presidents Nixon and Ford during the Vietnam War, was appointed as the first secretary.

President Carter created the Department of Energy with the goal of promoting energy conservation and developing alternative sources of energy. He wanted to not be dependent on foreign oil and reduce the use of fossil fuels. With international energy’s future uncertain for America, Carter acted quickly to have the department come into action the first year of his presidency. This was an extremely important issue of the time as the oil crisis was causing shortages and inflation. With the Three-Mile Island disaster, Carter was able to intervene with the help of the department. Carter made switches within the Nuclear Regulatory Commission in this case to fix the management and procedures. This was possible as nuclear energy and weapons are responsibility of the Department of Energy.


On March 28, 2017, a supervisor in the Office of International Climate and Clean Energy asked staff to avoid the phrases “climate change,” “emissions reduction,” or “Paris Agreement” in written memos, briefings or other written communication. A DOE spokesperson denied that phrases had been banned.

In a May 2019 press release concerning natural gas exports from a Texas facility, the DOE used the term ‘freedom gas’ to refer to natural gas. The phrase originated from a speech made by Secretary Rick Perry in Brussels earlier that month. Washington Governor Jay Inslee decried the term “a joke”.


The Department of Energy operates a system of national laboratories and technical facilities for research and development, as follows:

Ames Laboratory
Argonne National Laboratory
Brookhaven National Laboratory
Fermi National Accelerator Laboratory
Idaho National Laboratory
Lawrence Berkeley National Laboratory
Lawrence Livermore National Laboratory
Los Alamos National Laboratory
National Renewable Energy Laboratory
Oak Ridge National Laboratory
Pacific Northwest National Laboratory
Princeton Plasma Physics Laboratory
Sandia National Laboratories
Savannah River National Laboratory
SLAC National Accelerator Laboratory
Thomas Jefferson National Accelerator Facility
Other major DOE facilities include:
Albany Research Center
Bannister Federal Complex
Bettis Atomic Power Laboratory – focuses on the design and development of nuclear power for the U.S. Navy
Kansas City Plant
Knolls Atomic Power Laboratory – operates for Naval Reactors Program Research under the DOE (not a National Laboratory)
National Petroleum Technology Office
Nevada Test Site
New Brunswick Laboratory
Office of Fossil Energy
Office of River Protection
Radiological and Environmental Sciences Laboratory
Y-12 National Security Complex
Yucca Mountain nuclear waste repository

Pahute Mesa Airstrip – Nye County, Nevada, in supporting Nevada National Security Site