Scientists are using airplanes, sensors, radar, computer modeling programs and NASA satellites to better understand hurricanes. Some of the NASA satellites include Aqua, the Tropical Rainfall Measuring Mission (TRMM), and the recently-launched Cloudsat/CALIPSO satellite. Edward Zipser of the University of Utah, Salt City, is the chief mission scientist. Following is an on-location report from Dr. Zipser during the NAMMA Hurricane field mission.
Image right: Flying Around a Tropical Disturbance: This is an image from Google Earth that shows the flight path (red line) of NASA's DC-8 aircraft around a tropical disturbance (in red and blue) near the Cape Verde Islands, off the African coast. This was the flight path for August 23, 2006. Credit: NASA
Mission Scientist Report: August 23rd, 2006 - 3rd Science Flight
On August 23, 2006, scientists on the NAMMA mission took an eight hour flight into a tropical disturbance. Edward Zipser noted "surprisingly strong winds at 700 millibars (approximately 10,000 feet high), considering how the system seemed to be struggling to survive in the midst of the Sahara Air Layer."
Spotting Dry Air in a Storm
The Saharan Air Layer (SAL) is a mass of very dry, dusty air which forms over the Sahara Desert during the late spring, summer, and early fall and usually moves out over the tropical Atlantic Ocean. The SAL usually extends between 5,000-20,000 feet in the atmosphere and is associated with large amounts of mineral dust, dry air and strong winds (~25-55 mph).
Zipser said, "We saw evidence of dry air, typically from 750-550 millibars (10,000 to 19,000 feet), on almost all quadrants, but of course we won’t know right away how much of this air actually entered the inner core of the storm."
Communicating Between the Ground and Air
During the previous two flights into the tropical system, the scientists used a communications system called "X-Chat" system. The main advantage was that mission scientist, Jeff Halverson, who was on the ground, watched movie loops of the tropical system and he was able to pass information to the DC-8 aircraft, while the flight scientist could rapidly relay information back.
The scientists on the DC-8 aircraft noted that the storm structure they were flying over featured was not symmetrical (not identical on both sides of a central line) below about 6-7 kilometers (around 4 miles) altitude. They also noted that the system's strongest winds were on the east and north side.
Image/animation left:Animation of Dropsonde (Sensor): Researchers in high-flying planes drop temperature-taking instruments into tropical cyclones from about 3 miles above it. Described by a researcher as "Pringles cans with parachutes," sensors called 'dropsondes' are dropped into tropical cyclones to obtain temperature, pressure, moisture and wind readings throughout different locations of the storm. Credit: NASA
Another benefit to flying into a storm was that the scientists were able to better determine its exact location. The storm was found to be north of the forecast position. Zipser and his crew dropped about 24 dropsondes into the storm. A dropsonde is a sensor that measures temperature, pressure, moisture and winds throughout different locations of a storm.
Looking at Air Circulations Like a Layer Cake
When the scientists flew into the tropical cyclone, they noticed that there were two different air circulations happening, like layers of a cake. In the top layer, higher than the surface, (above 500-400 millibars or 20,000 feet), the center of the cyclone seemed to be well southeast of the cyclone that was on lower level (at the surface).
When the scientists flew over the “eye” or center of the tropical cyclone at a height of 35,000 feet, they we were continuously in thick cirrus clouds (wispy clouds made of ice crystals). Later, however, they were able to look at data from the PR-2 (an airborne radar) showing a sloping eyewall to 7 kilometers (4.3 miles).
Convection (rising air that condenses higher in the atmosphere to form clouds and storms) decreased during the flight with little or no significant turbulence and no large areas of organized rainfall from stratiform clouds (layered clouds).
Measuring the Winds Above and on the Surface
The dropsondes were not spaced closely enough to give a proper description of the wind circulation close to the center of the storm, so the plane carrying Zipser and his crew descended to 10,000 feet (700 millibars) where they mapped the winds on the north and east sides of the storm. Winds were about 40 to 50 nautical miles per hour (45-55 mph), and there were some winds in excess of 60 knots (70 mph). There were no strong winds on the south side of the storm. The scientists estimated the winds on the surface around 40-45 knots (45-51 mph).
Every flight into a storm gives scientists more information about how tropical cyclones work. The NAMMA mission ends in mid-September, 2006.
Rob Gutro | EurekAlert!
PR of MCC: Carbon removal from atmosphere unavoidable for 1.5 degree target
22.05.2018 | Mercator Research Institute on Global Commons and Climate Change (MCC) gGmbH
Monitoring lava lake levels in Congo volcano
16.05.2018 | Seismological Society of America
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.
Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
22.05.2018 | Life Sciences
22.05.2018 | Life Sciences
22.05.2018 | Life Sciences