Cooperative Institute for Research in Environmental Sciences

Emissions from oil and gas activities might influence local climate

Local air pollution on Alaska's North Slope appears to affect liquid clouds that form downwind, leading to smaller droplets less likely to fall as drizzle or rain, according to new research. Clouds in the region can either cool or warm the surface, depending on their specific properties and season. In the summertime, Arctic clouds generally cool the surface by reflecting sunlight, but changing droplet size may alter the degree of that cooling.

Because the Arctic is warming more rapidly than the rest of the planet, better understanding those clouds—and the pollution that affects them—is crucial to understanding future global climate change.

In this study, CIRES and NOAA scientists and collaborators compared liquid-containing clouds in two coastal regions in Alaska: Oliktok Point, which is close to the Prudhoe Bay oilfield, and the more atmospherically pristine Utqiaġvik (formerly called Barrow).

“It’s almost like a laboratory experiment: the two locations are very close geographically and their weather is similar, but they are very different in terms of emissions,” said Maximilian Maahn, the paper’s lead author and a postdoctoral research associate at the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder working in the NOAA Earth System Research Laboratory. “By comparing cloud observations from both sites, we can investigate how Arctic cloud properties and processes are modified by emissions from the Prudhoe Bay Oil Field.”

The Department of Energy’s Atmospheric Radiation Measurement (ARM) mobile facility site at Oliktok Point. Photo: U.S. Department of Energy ARM Facility.

The paper is published today in the journal Atmospheric Chemistry and Physics. In this study, the research team used aircraft observations and a pollution dispersion model to link differences in pollution from oil and gas activities to changes in cloud properties.

The data for this study came from the Department of Energy (DOE) Atmospheric Radiation Measurement Program’s Airborne Carbon Measurements 2015 field campaign, which included nearly 40 research flights from June to September. Even though the project’s main mission targeted trace gas emissions from the tundra, the aircraft also included an instrument that measured clouds and aerosols at Oliktok Point and Utqiaġvik.

The researchers compared the atmospheric composition of Oliktok Point, with all its oilfields, and Utqiaġvik. They found more pollution at Oliktok Point—more than twice as many condensation nuclei (the types of tiny airborne particles on which water vapor condenses to form droplets).

They also found that liquid clouds observed at Oliktok Point contained significantly smaller cloud droplets than at Utqiaġvik, conditions which result in less drizzle and rain formation in the polluted region. This reduced the rain rate there to about one-tenth and might have an impact on the lifetime of the clouds. The properties of the pollution particles observed near the clouds match those from oil production facilities, which makes a connection between the local emissions and the reduced cloud droplet size likely.

Liquid cloud effective radius, which describes the size of cloud drops, compared to liquid water content, which describes the mass of liquid drops per unit volume, color-coded according to the relative number of observations. Observations at Utqiaġvik/Barrow comprise a wider range of cloud drop sizes (3 to 27 um) than at Oliktok Point (mostly below 16 um, see dashed line), showing smaller cloud droplet sizes in the Prudhoe Bay region.

To further explore this connection, the researchers then used a NOAA-developed pollution dispersion model called HYSPLIT. The model tracks how emissions spread, incorporating weather conditions. Maahn and his colleagues found that, indeed, pollution from industrial activities in the Prudhoe Bay region could explain differences in the properties of liquid clouds.

“But even with pollution from Oliktok Point’s oil activities, the air is still relatively clean,” Maahn said. That suggests that clouds on Alaska’s North Slope are relatively sensitive, and small amounts of pollution have a demonstrable effect.

Now, the researchers want to quantify each step in the process, including the last one: Whether clouds downwind of pollution sources are likely to make the surface warmer or cooler. “Aircraft data are more like a snapshot: we did random samples of clouds and demonstrated this effect, but we can’t say how representative our results are,” said Maahn. “Measurements on the ground can provide continuous, long-term observations that could tell us whether there’s an impact on radiation and cloud lifetime. We want to know the percentage of clouds affected by pollution in this region of the Arctic.”     


CIRES is a partnership of NOAA and CU Boulder.

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The rapidly growing wind energy industry may be challenged by changes in locations of wind resources

In the next century, wind resources may decrease in many regions of the Northern Hemisphere and could sharply increase in some hotspot regions down south, according to a study by University of Colorado Boulder researchers. The first-of-its-kind study predicting how global wind power may shift with climate change appears today in Nature Geoscience.

“There's been a lot of research looking at the potential climate impact of energy production transformations—like shifting away from fossil fuels toward renewables,” said lead author Kris Karnauskas, CIRES Fellow and Assistant Professor in Atmospheric and Oceanic Sciences (ATOC)  at CU Boulder. “But not as much focuses on the impact of climate change on energy production by weather-dependent renewables, like wind energy.”

Wind powers only about 3.7 percent of worldwide energy consumption today, but global wind power capacity is increasing rapidly—about 20 percent a year. Karnauskas and colleagues Julie Lundquist and Lei Zhang, also in ATOC, wanted to better understand likely shifts in production, so they turned to an international set of climate model outputs to assess changes in wind energy resources across the globe. The team then used a "power curve" from the wind energy industry to convert predictions of global winds, density and temperature into an estimate of wind energy production potential.

While not all of the climate models agreed on what the future will bring, substantial changes may be in store, especially a prominent asymmetry in wind power potential across the globe. If carbon dioxide emissions continue at high levels, wind power resources may decrease in the Northern Hemisphere’s mid-latitudes, and increase in the Southern Hemisphere and tropics by 2100.

Strangely, the team also found that if emission levels are mitigated, dropping lower in coming decades, they see only a reduction of wind power in the north—it may not be countered with an increase of power in the south.

Renewable energy decision makers typically plan and install wind farms in areas with consistently strong winds today. For example, the prairies of the American Midwest—persistently windy today and in recent decades—are dotted with tens of thousands of turbines. While the new assessment finds wind power production in these regions over the next twenty years will be similar to that of today, it could drop by the end of the century.

By contrast, potential wind energy production in northeastern Australia could see dramatic increases.

Potential global wind power in coming years. Top images represent next 40 years, bottom images represent next 80 years. Left images represent lower emissions, right images represent higher emissions scenario. Red areas are wind power hotspots, blue areas are reductions. White areas are uncertain. Image: Kris Karnauskas/CIRES

There were different reasons for the Northern decline and the Southern increase in wind power potential in the high-emissions scenario, Karnauskas and his co-authors found in their analysis of modeling results. In the Northern Hemisphere, warmer temperatures at the North Pole weaken the temperature difference between this cold region and the warm equator. A smaller temperature gradient means slower winds in the northern mid-latitudes.

“These decreases in North America occur primarily during the winter season, when those temperature gradients should be strong and drive strong winds,” said Associate Professor Lundquist, who is also a RASEI Fellow. In addition to North America, the team identified possible wind power reductions in Japan, Mongolia and the Mediterranean by the end of the century. This may be bad news for the Japanese, who are rapidly accelerating their wind power development.

In the Southern Hemisphere, where there is more ocean than land, a different kind of gradient increases: land warms faster than the surrounding, much-larger oceans. That intensified gradient increases the winds. Hotspots for likely wind power increases include: Brazil, West Africa, South Africa and Australia.

"Europe is a big question mark,” added Karnauskas. “We have no idea what we'll see there. That's almost scary, given that Europe is producing a lot of wind energy already.” The trend in this region (and in others, like the southeastern United States) is just too uncertain: some models forecast wind power increase, and others, a decrease.

In a warming world, harnessing more wind power in coming decades could be critical for countries trying to meet emission reduction standards set by the Paris Climate Agreement. The team’s results may help inform decision-makers across the globe determining where to deploy this technology.

“The climate models are too uncertain about what will happen in highly productive wind energy regions, like Europe, the Central United States, and Inner Mongolia,” said Lundquist. “We need to use different tools to try to forecast the future—this global study gives us a roadmap for where we should focus next with higher-resolution tools.”

CIRES is a partnership of NOAA and CU Boulder.

The Cooperative Institute for Research in Environmental Sciences (CIRES), has an opening for a position to study the cellular and molecular effects of synonymous mutations during adaptive evolution in the research group of Dr. Shelley Copley (Molecular, Cellular, and Developmental Biology). 

The Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder collaborates with the National Oceanic and Atmospheric Administration (NOAA) located at the Earth System Research Lab (ESRL), Global Systems Division (GSD) in Boulder, CO. GSD’s Evaluation and Decision Support Branch (EDS) is on the forefront in developing new systems for National Weather Service (NWS) forecasters who require display of, and interaction with, real-time weather data. For example, a key function is the generation of warnings or hazard information for severe weather events such as tornadoes, hurricanes, and floods.

The Mission

EDS has been tasked with the creation of a variety of applications to enable forecasters to work more quickly and efficiently for both routine tasks and in critical weather situations. The host for these applications is called AWIPS II (the 2nd generation of the Advanced Weather Interactive Processing System). It is evolving into an advanced observational, forecasting, communications, computational, and display system. It uses service-oriented architecture and is written in Java and Python using the Eclipse framework.

The near-term focus will be on applications and extensions to services that support diverse phenomena such as thunderstorms, winter, tropical, and aviation weather, plus new ground-breaking techniques through continuous and probabilistic information paradigms.

The Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder collaborates with the National Oceanic and Atmospheric Administration (NOAA) located at the Earth System Research Lab (ESRL), Global Systems Division (GSD) in Boulder, CO.

The Weather Information System Evolution (WISE) section within GSD develops weather-related software, systems, and associated tools used by numerous governmental agencies (domestic and international).  A primary focus of WISE is developing improvements to the Advanced Weather Information Processing System (AWIPS) II, a computer system used by the National Weather Service around the country. This system consists of software written primarily in Java and Python code. 

One key development effort by WISE is the creation of Hazard Services.  Hazard Services is a multi-year effort, and one foundational aspect of the program is to combine the capabilities of AWIPS WarnGen, Graphical Hazard Generator, and RiverPro into a single application. Currently, these critical applications allow NWS forecasters to produce hazard watch, warning, and advisory products and deliver various services.  Other development areas for Hazard Services have, or will soon, include probabilistic hazard information, applications at NWS National Centers, and potential applications for international agencies.  All three of these efforts require testing and evaluation of the software and associated work flows.

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