Success Stories

Black Marble science team, which includes SSAI scientist Ranjay M. Shrestha Ph.D., developed, maintains and manages NASA’s Black Marble product — which multiple government and scientific agencies actively use to measure the impact of natural disasters on the electric grid, monitor the effects of conflict and population displacement, map urbanization, track electricity and light pollution, and understand activity patterns within human settlements.

Overview

NASA’s Black Marble nighttime lights product suite (VNP46) is derived from the Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) aboard the Suomi National Polar-orbiting Platform (SNPP). The product is routinely available through the NASA Level 1 and Atmosphere Archive and Distribution System (LAADS) Distributed Active Archive Center (DAAC). The Black Marble science team developed the NASA Black Marble algorithm to convert raw imagery into science-quality cloud-free daily global nighttime light data that has been corrected for non-anthropogenic light sources (e.g., moonlight, airglow, auroras), atmospheric constituents (e.g., dust, haze, cloud), and surface reflection effects (e.g., snow, fire, vegetation cover).

Science-quality cloud-free daily global nighttime light data that has been corrected for non-anthropogenic light sources

These corrections provide superior retrieval of nighttime light observations enabling quantitative analyses of daily, seasonal, and annual variations of outdoor lighting on a global scale. The standard (Level 3 daily) and multi-date composite products are available at 500 m spatial resolution from January 2012 to present. The standard products are being processed daily, within 3-5 hours after acquisition, and can be utilized as an efficient tool for both rapid assessments and long-term monitoring. 

Results

The product is being routinely generated to enable near-real-time applications of the data, in addition to long-term fundamental research.  

The product suite has assessed disruptions in energy infrastructure and utility services following major disasters, as well as to track progress as these services are slowly restored. Examples include but are not limited to: hurricane Maria in Puerto Rico (2017), hurricanes Florence and Michael in North Carolina and Florida, respectively (2018); and cyclones Idai and Fani, and hurricane Dorian in Mozambique, India, and the Bahamas (2019), respectively. Subsequently, the data researchers gathered allowed them to analyze the relationship between restoration rates in terms of days without electricity and the remoteness of communities from major cities. Notably, during hurricane Florence, soldiers at the Fort Bragg obtained pre- and post-event mapping of Black Marble power outage images on their cell phones and used them to assess power outages on their army base. These rapid assessment maps were available to soldiers in near-real-time and allowed the base to maintain security despite the outages. 

The product has also played an integral role in producing power outage maps during the unprecedented Texas winter storm of 2020 and 2021, where the outage spanned the entire state of Texas (the only state in the U.S. that has isolated its power grid from the rest of the country). 

In mid-February 2021, a potent arctic weather system brought extreme cold as well as several snow and ice storms to the U.S., which left millions without power.

Feb. 7 – Houston, Texas, before a winter storm, fully powered (left); Feb. 16 - Houston, Texas, following the winter storm with large scale blackouts (right).

In the context of research, Black Marble has been instrumental in assessing human-driven patterns and allowing researchers to gain a new perspective on the impacts of human activity on Earth. Scientists can tell where infrastructure is, frequency of use and how human settlements grow and change over time. This allows scientists to tackle questions about urbanization such as whether cities are becoming more or less sustainable, how they consume resources, and what drives human movement around the globe. 

 

Many of the largest cities and towns in Pakistan are clustered along the Indus River. It's also possible to see the border between Pakistan and India as its lights stand out against the landscape.

Most recently, researched have used Black Marble to monitor the impacts of the ongoing COVID-19 pandemic. During the beginning stages of the outbreak, Black Marble-derived images captured the impact of widespread shutdowns on businesses and transportation in Wuhan — ground zero of the outbreak — and around the Hubei province in central China. Black Marble was also one of the four research projects selected and funded to study COVID-19 impacts through NASA’s Rapid Response and Novel Research in Earth Science (RRNES) initiative. Furthermore, it was included as one of the socio-economic indicators in the tri-agency COVID-19 Dashboard — a concerted effort between the European Space Agency (ESA), Japan Aerospace Exploration Agency (JAXA), and NASA. The dashboard combined the resources, technical knowledge, and expertise of the three partner agencies to strengthen our global understanding of the environmental and economic effects of the COVID-19 pandemic. They used nighttime light to serve as socio-economic indicators which provided information about variations in energy use, migration, and transportation in response to social distancing and lockdown procedures.  

Given the societal benefits and research applications Black Marble has to offer, SSAI is proud to be part its success. SSAI scientists play a critical role in the Black Marble science team by maintaining the quality of the product, curating the website with the latest product updates, providing end-user training and support, and developing special products and images for disaster response and outreach efforts.