OrbitalHub

NASA dicit:

In April, instruments aboard NASA’s Operation IceBridge airborne campaign and the Ice, Cloud and Land Elevation Satellite-2 succeeded in measuring the same Arctic sea ice at the same time, a tricky feat given the shifting sea ice. Scientists have now analyzed airborne and spaceborne height measurements, and found that the two datasets match almost exactly, demonstrating how precisely ICESat-2 can measure the heights of the sea ice’s bumpy, cracked surface.

Video Credit: NASA Goddard

NASA dicit:

Arctic sea ice likely reached its 2019 minimum extent of 1.60 million square miles (4.15 million square kilometers) on Sept. 18, tied for second lowest summertime extent in the satellite record, according to NASA and the National Snow and Ice Data Center.

The Arctic sea ice cap is an expanse of frozen seawater floating on top of the Arctic Ocean and neighboring seas. Every year, it expands and thickens during the fall and winter and grows smaller and thinner during the spring and summer. But in the past decades, increasing temperatures have caused marked decreases in the Arctic sea ice extents in all seasons, with particularly rapid reductions in the minimum end-of-summer ice extent. The shrinking of the Arctic sea ice cover can ultimately affect local ecosystems, global weather patterns, and the circulation of the oceans.

Video Credit: NASA Goddard/Lead Producer: Katie Jepson (USRA); Technical Support: Aaron E. Lepsch (ADNET); Scientists: Nathan T. Kurtz (NASA/GSFC), Walt Meier (NASA/GSFC); Lead Visualizers: Trent L. Schindler (USRA), Cindy Starr (GST); Lead Animator: Bailee DesRocher (USRA); Narrator: LK Ward (USRA); Visualizer: Lori Perkins (NASA/GSFC); Lead Writer: Maria-Jose Vinas Garcia (Telophase); Videographers: Kate Ramsayer (Telophase), Jefferson Beck (USRA), John Caldwell (AIMM)

NASA dicit:

High temperatures and low humidity are two essential factors behind the rise in fire risk and activity, affecting fire behavior from its ignition to its spread. Even before a fire starts they set the stage, said Jim Randerson, an Earth system scientist at the University of California, Irvine who studies fires both in the field and with satellite data.

He and his colleagues studied the abundance of lightning strikes in the 2015 Alaskan fire season that burned a record 5.1 million acres. Lightning strikes are the main natural cause of fires. The researchers found an unusually high number of lightning strikes occurred, generated by the warmer temperatures that cause the atmosphere to create more convective systems — thunderstorms — which ultimately contributed to more burned area that year.

Video Credit: NASA

Wikipedia dicit:

Hurricane Dorian is a strong tropical cyclone currently affecting the Bahamas and the Southeastern United States. The fourth named storm, second hurricane, and first major hurricane of the 2019 Atlantic hurricane season, Dorian developed from a tropical wave on August 24 in the Central Atlantic. The system gradually intensified while moving toward the Lesser Antilles, before becoming a hurricane on August 28. Rapid intensification ensued, and on August 31, Dorian intensified into a Category 4 major hurricane. On the following day, Dorian reached Category 5 intensity, peaking with one-minute sustained winds of 185 mph (295 km/h) and a minimum central pressure of 910 millibars (26.87 inHg) while making landfall in Elbow Cay, Bahamas, at 16:40 UTC. Dorian made another landfall on Grand Bahama several hours later, near the same intensity.

From August 26–28, the storm affected Caribbean nations and territories devastated by hurricanes Irma and Maria in 2017. Extensive precautionary measures were taken to mitigate damage, especially in Puerto Rico, where one person died. Damaging winds primarily affected the Virgin Islands where gusts reached 111 mph (179 km/h). Elsewhere in the Lesser Antilles, impacts from the storm were relatively minor.

Video Credit: NASA

NASA dicit:

NASA, NOAA and university partners are taking to the skies, and the ground, to chase smoke from fires burning across the United States. The Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) is starting in Boise, Idaho, with a long-term of goal of improving our understanding of how smoke from fires affects air quality across North America.

Credit: NASA’s Goddard Space Flight Center/Scientific Visualization Studio/Kathryn Mersmann (USRA): Lead Producer/Samson K. Reiny (Wyle Information Systems): Lead Writer/Alex Kekesi (GST): Lead Visualizer/LK Ward (USRA): Producer/Ellen T. Gray (ADNET): Producer/Music: “Broad Horizons” by Chris White [PRS] from Killer Tracks

NASA dicit:

The varied landscapes of the United States have unique relationships with water. On the East Coast, rain is a regular occurrence. In the West, drought is a constant threat. Rivers and lakes fed by rainfall, snowmelt or a mix of both provide two-thirds of the country’s drinking water while also supporting agriculture. Managing these water resources requires balancing growing demand for water in the face of shifting availability and changing climate. Many state and federal agencies and other organizations turn to NASA research, satellite data and analytical tools to help tackle these issues.

Since the 1960s, NASA has been steadily expanding its view of how fresh water moves around the planet. Early satellites that imaged clouds and snow cover evolved to more recent missions that quantify rain and snowfall worldwide every half-hour, make daily observations of global snow cover, detect changes in aquifers deep underground, and monitor moisture in soils every few days. These observations are some of the most powerful assets scientists have when studying the water cycle, how it affects people and their water supplies, and how it may change in a warming climate. At NASA, researchers maintain and refine these data sets, providing them to the public at no cost. NASA researchers also help to interpret the information with sophisticated computer programs that integrate the disparate data sets and fill gaps to create a coherent picture of where and how water moves around the planet every day.

Video Credit: NASA Goddard