Experimental Power Loss Algorithm for Alaska Floods October 2025 (Beta; experimental) v0.3.1

This dataset is experimental and should only be used for situational awareness and data corroboration. Derived luminosity loss maps are processed data based off Black Marble BRDF nighttime light observations. This data may be used as a proxy for power loss. The original BRDF data is available at: https://gis.earthdata.nasa.gov/portal/home/item.html?id=654bc62d78fc4704923369a00a635937 Dates of Image: Pre-Event: September 2025 Post-Event: October 30, 2025-November 2, 2025; November 4, 2025; November 7, 2025; November 8, 2025; November 9, 2025 Methodology: Only a subset of the raw black marble data was used. Note that while the Disasters team has clipped data to remove false positives, some observations may be obscured by total or partial cloud cover. Other factors such as snow reflectance, moon phase, wildfires, and wildfire smoke may distort light radiance and require further analysis when assessing power outages. Certain areas were filtered out into an “Analyzed areas” map, which shows subsets of counties that were retained after certain data extents were removed: Baseline (August 2024) data with low radiance ( Cloud cover from the date of interest (in this example, September 29th) is removed from the county geometry. Counties are only included within the bounding box of the Black Marble data that was provided. Once the extent was finalized, the Black Marble Data was modified: Negative out-of-range values were changed to 0. The revised black marble pixels were extracted to the analyzed area geometry: The difference between pre and post-event total light intensity in each county was calculated to measure percent light intensity loss. This is indicated in popups as Light Intensity Loss (percentage). The percentage of analyzed area (with area omitted due to being background in the baseline or cloud-covered in the day of Black Marble) is also available in the attribute table. Lower values may reflect lower confidence in the percent Luminosity Loss depending on where the cloud cover is, especially in circumstances where the primary light source in a given geometry is obfuscated. Suggested Use: NASA's Black Marble Nighttime Light product suite is a state-of-the-art daily global collection of standard products for monitoring nighttime lights (NTL). Utilizing the Visible Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) aboard the Suomi-NPP, NOAA-20, and NOAA-21 satellites. Grey represents cloud cover. Note that these maps are experimental and subject to change and development and should be used only for situational awareness. Satellite/Sensor: Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) onboard the Suomi National Polar-orbiting Platform (SNPP), NOAA-20, and NOAA-21 SNPP: August 2024 composite, September 22-24, 2024, October 1, 2024 NOAA-20: September 25 - September 31, 2024, October 2, 2024 - October 4, 2024 Resolution: 500 meters Credits: NASA Black Marble Science team Disasters Response Coordination System Please cite the following two references when using this data: Román MO, Stokes EC, Shrestha R, Wang Z, Schultz L, Carlo EA, Sun Q, Bell J, Molthan A, Kalb V, Ji C. Satellite-based assessment of electricity restoration efforts in Puerto Rico after Hurricane Maria. PloS one. 2019 Jun 28;14(6):e0218883. Román MO, Wang Z, Sun Q, Kalb V, Miller SD, Molthan A, Schultz L, Bell J, Stokes EC, Pandey B, Seto KC. NASA's Black Marble nighttime lights product suite. Remote Sensing of Environment. 2018 Jun 1;210:113-43. Point of Contact: Ranjay Shrestha NASA Goddard Space Flight Center E-mail: ranjay.m.shrestha@nasa.gov Additional Links: NASA’s Black Marble Product Suite Román, M.O. et al. (2019) Satellite-based assessment of electricity restoration efforts in Puerto Rico after Hurricane Maria. PLoS One, 14 (6). Román, M.O. et al. (2018) NASA’s Black Marble nighttime lights product suite. Remote Sensing of Environment. 210, 113–143. Esri REST Endpoint: See URL to the right. WMS Endpoint: https://gis.earthdata.nasa.gov/portal/services/DISASTERS_202510_HURRICANE_MELISSA/BM_PowerLossProxy/MapServer/WMSServer

This dataset is experimental and should only be used for situational awareness and data corroboration. Derived luminosity loss maps are processed data based off Black Marble BRDF nighttime light observations. This data may be used as a proxy for power loss. The original BRDF data is available at: https://gis.earthdata.nasa.gov/portal/home/item.html?id=62cf0b48eeb744e0a9ced76f6326a03c Dates of Image: Post-Event: April 18, 2026; April 19, 2026 Pre-Event: March 2026 Methodology: Only a subset of the raw black marble data was used. Note that while the Disasters team has clipped data to remove false positives, some observations may be obscured by total or partial cloud cover. Other factors such as snow reflectance, moon phase, wildfires, and wildfire smoke may distort light radiance and require further analysis when assessing power outages. Certain areas were filtered out into an “Analyzed areas” map, which shows subsets of counties that were retained after certain data extents were removed: Baseline (March 2026) data with low radiance ( Cloud cover from the date of interest (in this example, September 29th) is removed from the county geometry. Counties are only included within the bounding box of the Black Marble data that was provided. Once the extent was finalized, the Black Marble Data was modified: Negative out-of-range values were changed to 0. The revised black marble pixels were extracted to the analyzed area geometry: The difference between pre and post-event total light intensity in each county was calculated to measure percent light intensity loss. This is indicated in popups as Light Intensity Loss (percentage). The percentage of analyzed area (with area omitted due to being background in the baseline or cloud-covered in the day of Black Marble) is also available in the attribute table. Lower values may reflect lower confidence in the percent Luminosity Loss depending on where the cloud cover is, especially in circumstances where the primary light source in a given geometry is obfuscated. Suggested Use: NASA's Black Marble Nighttime Light product suite is a state-of-the-art daily global collection of standard products for monitoring nighttime lights (NTL). Utilizing the Visible Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) aboard the Suomi-NPP, NOAA-20, and NOAA-21 satellites. Grey represents cloud cover. Note that these maps are experimental and subject to change and development and should be used only for situational awareness. Satellite/Sensor: Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) onboard the Suomi National Polar-orbiting Platform (SNPP), NOAA-20, and NOAA-21 SNPP: August 2024 composite, September 22-24, 2024, October 1, 2024 NOAA-20: September 25 - September 31, 2024, October 2, 2024 - October 4, 2024 Resolution: 500 meters Credits: NASA Black Marble Science team Disasters Response Coordination System Please cite the following two references when using this data: Román MO, Stokes EC, Shrestha R, Wang Z, Schultz L, Carlo EA, Sun Q, Bell J, Molthan A, Kalb V, Ji C. Satellite-based assessment of electricity restoration efforts in Puerto Rico after Hurricane Maria. PloS one. 2019 Jun 28;14(6):e0218883. Román MO, Wang Z, Sun Q, Kalb V, Miller SD, Molthan A, Schultz L, Bell J, Stokes EC, Pandey B, Seto KC. NASA's Black Marble nighttime lights product suite. Remote Sensing of Environment. 2018 Jun 1;210:113-43. Point of Contact: Ranjay Shrestha NASA Goddard Space Flight Center E-mail: ranjay.m.shrestha@nasa.gov Additional Links: NASA’s Black Marble Product Suite Román, M.O. et al. (2019) Satellite-based assessment of electricity restoration efforts in Puerto Rico after Hurricane Maria. PLoS One, 14 (6). Román, M.O. et al. (2018) NASA’s Black Marble nighttime lights product suite. Remote Sensing of Environment. 210, 113–143. Esri REST Endpoint: See Layers below. WMS Endpoint: https://gis.earthdata.nasa.gov/portal/services/DISASTERS_202606_TYPHON_SINLAKU/BM_PowerLossProxy/MapServer/WMSServer

This dataset is experimental and should only be used for situational awareness and data corroboration. Derived luminosity loss maps are processed data based off Black Marble BRDF nighttime light observations. This data may be used as a proxy for power loss. The original BRDF data is available at: https://gis.earthdata.nasa.gov/portal/home/item.html?id=62cf0b48eeb744e0a9ced76f6326a03c Dates of Image: Post-Event: April 18, 2026; April 19, 2026 Pre-Event: March 2026 Methodology: Only a subset of the raw black marble data was used. Note that while the Disasters team has clipped data to remove false positives, some observations may be obscured by total or partial cloud cover. Other factors such as snow reflectance, moon phase, wildfires, and wildfire smoke may distort light radiance and require further analysis when assessing power outages. Certain areas were filtered out into an “Analyzed areas” map, which shows subsets of counties that were retained after certain data extents were removed: Baseline (March 2026) data with low radiance ( Cloud cover from the date of interest (in this example, September 29th) is removed from the county geometry. Counties are only included within the bounding box of the Black Marble data that was provided. Once the extent was finalized, the Black Marble Data was modified: Negative out-of-range values were changed to 0. The revised black marble pixels were extracted to the analyzed area geometry: The difference between pre and post-event total light intensity in each county was calculated to measure percent light intensity loss. This is indicated in popups as Light Intensity Loss (percentage). The percentage of analyzed area (with area omitted due to being background in the baseline or cloud-covered in the day of Black Marble) is also available in the attribute table. Lower values may reflect lower confidence in the percent Luminosity Loss depending on where the cloud cover is, especially in circumstances where the primary light source in a given geometry is obfuscated. Suggested Use: NASA's Black Marble Nighttime Light product suite is a state-of-the-art daily global collection of standard products for monitoring nighttime lights (NTL). Utilizing the Visible Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) aboard the Suomi-NPP, NOAA-20, and NOAA-21 satellites. Grey represents cloud cover. Note that these maps are experimental and subject to change and development and should be used only for situational awareness. Satellite/Sensor: Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) onboard the Suomi National Polar-orbiting Platform (SNPP), NOAA-20, and NOAA-21 SNPP: August 2024 composite, September 22-24, 2024, October 1, 2024 NOAA-20: September 25 - September 31, 2024, October 2, 2024 - October 4, 2024 Resolution: 500 meters Credits: NASA Black Marble Science team Disasters Response Coordination System Please cite the following two references when using this data: Román MO, Stokes EC, Shrestha R, Wang Z, Schultz L, Carlo EA, Sun Q, Bell J, Molthan A, Kalb V, Ji C. Satellite-based assessment of electricity restoration efforts in Puerto Rico after Hurricane Maria. PloS one. 2019 Jun 28;14(6):e0218883. Román MO, Wang Z, Sun Q, Kalb V, Miller SD, Molthan A, Schultz L, Bell J, Stokes EC, Pandey B, Seto KC. NASA's Black Marble nighttime lights product suite. Remote Sensing of Environment. 2018 Jun 1;210:113-43. Point of Contact: Ranjay Shrestha NASA Goddard Space Flight Center E-mail: ranjay.m.shrestha@nasa.gov Additional Links: NASA’s Black Marble Product Suite Román, M.O. et al. (2019) Satellite-based assessment of electricity restoration efforts in Puerto Rico after Hurricane Maria. PLoS One, 14 (6). Román, M.O. et al. (2018) NASA’s Black Marble nighttime lights product suite. Remote Sensing of Environment. 210, 113–143. Esri REST Endpoint: See Layers below. WMS Endpoint: https://gis.earthdata.nasa.gov/gis05/services/DISASTERS_202606_TYPHON_SINLAKU/BM_PowerLossProxy/MapServer/WMSServer

Date of Images: 10/9/2025 - 10/28/2025 Please Note: Images with majority cloud cover are not shown in the Map Viewer, but are available in the service. Summary: These Black Marble Day-Night Band (BRDF-Corrected) cloud masks were created by the NASA Black Marble Science team. This is the layer to displaying where clouds are present. This comparison between the images is meant as a visual assessment of outage impacts to aid various partners who are working to deliver emergency aids to local communities. Power outage maps like these help disaster response efforts in the short-term as well as long-term monitoring during the crucial stages of disaster recovery. Suggested Use: NASA's Black Marble Nighttime Light product suite is a state-of-the-art daily global collection of standard products for monitoring nighttime lights (NTL). Utilizing the Visible Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) aboard the Suomi-NPP, NOAA-20, and NOAA-21 satellites. Grey represents cloud cover. Satellite/Sensor: Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) onboard the Suomi National Polar-orbiting Platform (SNPP), NOAA-20, and NOAA-21 Resolution: 500 meters Credits: NASA Black Marble Science team Please cite the following two references when using this data: Román MO, Stokes EC, Shrestha R, Wang Z, Schultz L, Carlo EA, Sun Q, Bell J, Molthan A, Kalb V, Ji C. Satellite-based assessment of electricity restoration efforts in Puerto Rico after Hurricane Maria. PloS one. 2019 Jun 28;14(6):e0218883. Román MO, Wang Z, Sun Q, Kalb V, Miller SD, Molthan A, Schultz L, Bell J, Stokes EC, Pandey B, Seto KC. NASA's Black Marble nighttime lights product suite. Remote Sensing of Environment. 2018 Jun 1;210:113-43. Point of Contact: Ranjay Shrestha NASA Goddard Space Flight Center E-mail: ranjay.m.shrestha@nasa.gov Additional Links: NASA’s Black Marble Product Suite Román, M.O. et al. (2019) Satellite-based assessment of electricity restoration efforts in Puerto Rico after Hurricane Maria. PLoS One, 14 (6). Román, M.O. et al. (2018) NASA’s Black Marble nighttime lights product suite. Remote Sensing of Environment. 210, 113–143. Service URL: https://gis.earthdata.nasa.gov/portal/home/item.html?id=961f83b5aef64f75bc4caa9c4610f4ed WMS Endpoint: https://gis.earthdata.nasa.gov/portal/services/DISASTERS_202510_FLOOD_AK/2510_BlackMarble_brdf_cloud/ImageServer/WMSServer

Date of Images: Post-Event: Pre-Event: September 2026 Summary: These Black Marble Day-Night Band (BRDF-Corrected) images were created by the NASA Black Marble Science team. The images are corrected for atmospheric, terrain, lunar BRDF, and straylight effects, and directly measures light intensity on the ground in units of nanowatts/(steradian centimeter squared). The images are scaled from 0 - 30. The baseline image is from May 2026, generated from all daily atmospheric and lunar-corrected data from that month. There is a layer to display where clouds are present. This comparison between the images is meant as a visual assessment of outage impacts to aid various partners who are working to deliver emergency aids to local communities. Power outage maps like these help disaster response efforts in the short-term as well as long-term monitoring during the crucial stages of disaster recovery. Suggested Use: NASA's Black Marble Nighttime Light product suite is a state-of-the-art daily global collection of standard products for monitoring nighttime lights (NTL). Utilizing the Visible Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) aboard the Suomi-NPP, NOAA-20, and NOAA-21 satellites. The image is in inferno color scale. Yellow represents presence of more light; dark blue less lights. Observations may be obscured by total or partial cloud cover. Other factors such as snow reflectance, moon phase, wildfires, and wildfire smoke may distort light radiance and require further analysis when assessing power outages. Satellite/Sensor: Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) onboard the Suomi National Polar-orbiting Platform (SNPP), NOAA-20, and NOAA-21 Resolution: 15 arc-seconds (~500 meters) Credits: NASA Black Marble Science team Please cite the following two references when using this data: Román MO, Stokes EC, Shrestha R, Wang Z, Schultz L, Carlo EA, Sun Q, Bell J, Molthan A, Kalb V, Ji C. Satellite-based assessment of electricity restoration efforts in Puerto Rico after Hurricane Maria. PloS one. 2019 Jun 28;14(6):e0218883. Román MO, Wang Z, Sun Q, Kalb V, Miller SD, Molthan A, Schultz L, Bell J, Stokes EC, Pandey B, Seto KC. NASA's Black Marble nighttime lights product suite. Remote Sensing of Environment. 2018 Jun 1;210:113-43. Point of Contact: Ranjay Shrestha NASA Goddard Space Flight Center E-mail: ranjay.m.shrestha@nasa.gov Additional Links: NASA’s Black Marble Product Suite Román, M.O. et al. (2019) Satellite-based assessment of electricity restoration efforts in Puerto Rico after Hurricane Maria. PLoS One, 14 (6). Román, M.O. et al. (2018) NASA’s Black Marble nighttime lights product suite. Remote Sensing of Environment. 210, 113–143.

Date of Images: Post-Event: April 26, 2024-May 22, 2024 (Daily) Pre-Event: April 2024 (Composite) Summary: These Black Marble Day-Night Band (BRDF-Corrected) images were created by the NASA Black Marble Science team. The images are corrected for atmospheric, terrain, lunar BRDF, and straylight effects, and directly measures light intensity on the ground in units of nanowatts/(steradian centimeter squared). The images are scaled from 0 - 30. The baseline image is from September 2025, generated from all daily atmospheric and lunar-corrected data from that month. There is a layer to display where clouds are present. This comparison between the images is meant as a visual assessment of outage impacts to aid various partners who are working to deliver emergency aids to local communities. Power outage maps like these help disaster response efforts in the short-term as well as long-term monitoring during the crucial stages of disaster recovery. Suggested Use: NASA's Black Marble Nighttime Light product suite is a state-of-the-art daily global collection of standard products for monitoring nighttime lights (NTL). Utilizing the Visible Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) aboard the Suomi-NPP, NOAA-20, and NOAA-21 satellites. The image is in inferno color scale. Yellow represents presence of more light; dark blue less lights. Observations may be obscured by total or partial cloud cover. Other factors such as snow reflectance, moon phase, wildfires, and wildfire smoke may distort light radiance and require further analysis when assessing power outages. Satellite/Sensor: Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) onboard the Suomi National Polar-orbiting Platform (SNPP), NOAA-20, and NOAA-21 Resolution: 500 meters Credits: NASA Black Marble Science team Please cite the following two references when using this data: Román MO, Stokes EC, Shrestha R, Wang Z, Schultz L, Carlo EA, Sun Q, Bell J, Molthan A, Kalb V, Ji C. Satellite-based assessment of electricity restoration efforts in Puerto Rico after Hurricane Maria. PloS one. 2019 Jun 28;14(6):e0218883. Román MO, Wang Z, Sun Q, Kalb V, Miller SD, Molthan A, Schultz L, Bell J, Stokes EC, Pandey B, Seto KC. NASA's Black Marble nighttime lights product suite. Remote Sensing of Environment. 2018 Jun 1;210:113-43. Point of Contact: Ranjay Shrestha NASA Goddard Space Flight Center E-mail: ranjay.m.shrestha@nasa.gov Additional Links: NASA’s Black Marble Product Suite Román, M.O. et al. (2019) Satellite-based assessment of electricity restoration efforts in Puerto Rico after Hurricane Maria. PLoS One, 14 (6). Román, M.O. et al. (2018) NASA’s Black Marble nighttime lights product suite. Remote Sensing of Environment. 210, 113–143. Service URL: See REST Endpoint on the right. WMS Endpoint: https://gis.earthdata.nasa.gov/portal/services/DISASTERS_202510_HURRICANE_MELISSA/BlackMarble_BRDF/ImageServer/WMSServer