Study: Bakken at night isn’t that bright

By The Bakken Magazine Staff | July 15, 2015

Millions have seen the satellite images from space in publications such as National Geographic and circulated on the Internet which purportedly show gas flaring in the Bakken making the night sky glow more brightly than large metropolitan areas.

However, a study conducted by the University of North Dakota Energy & Environmental Research Center and the school’s John D. Odegard School of Aerospace Sciences concluded that the photos create a misleading public perception.

“Results of this work suggest that popular satellite images of North Dakota’s night sky are a result of highly processed data from highly sensitive sensors that amplify light and heat sources from a variety of sources, including manufacturing plants, residences, construction sites, and gas production activities,” says Chris Zygarlicke, EERC deputy associate director for research.

Using images available through the National Oceanic and Atmospheric Administration (NOAA), researchers at UND developed improved methods for identifying, characterizing and processing flare images for several locations in western North Dakota.

Xiaodong Zhang, associate professor in UND’s Department of Earth System Science and Policy, says the problem with the satellite photos allegedly showing the full extent gas flaring in the Bakken is that the technology used to record the images is measuring heat, not light.

In addition, the study notes that the images are highly processed to amplify the heat spots from flaring, making them appear far larger and far brighter than they really are. When using satellite imaging technology designed to show light rather than heat, highly populated urban areas are far more visible in comparison to the faintly lit area of the Bakken.

“Even though a flare gives off a lot of heat, it’s not that bright,” Zhang says.

To illustrate how heat and light comparisons can be deceiving, the report compares a photo of a lit incandescent bulb to a photo of a candle flame. Even though the bulb is a thousand times brighter than the flame, it appears brighter because of the heat it emits.

Knowing that light-sensitive satellite imaging technology didn’t have high enough resolution to capture individual flares is one reason Zhang says researchers doubted that the photos were actually showing what they claimed. They began studying and comparing the images after receiving a university research seed grant in late 2013.

“Even when you take a picture of the sun with your camera, it’s a tiny spot, but it appears to be spread out over a big, big area—it’s saturated,” Zhang explained.

“When you look at the Bakken at night using a highly sensitive sensor, it does the same thing,” he continued. “The saturation is flooded to make a big blob. It doesn’t actually mean that the flare’s that big. It’s more a technical saturation issue than the actual size of the brightness.”

He also noted that gas flares are much more widely spaced in comparison to the lights of a city, which are densely packed. Satellite sensors designed to record heat rather than light tend to greatly exaggerate the amount of light a flare generates, Zhang said.