Hawaiian Islands weather details & Aloha paragraphs / September 11-12, 2010

Interesting: Yellowstone Park is a somewhat dormant super volcano site full of fuming vents and hot geysers. A plume of molten rock rising from deep beneath Yellowstone National Park is probably what is fueling the region’s volcanic activity, as well as tectonic plate oddities across the Pacific Northwest, new research suggests.

Yellowstone, like Hawaii, is believed to lie on top of an area called a hotspot where light, hot, molten mantle rock rises towards the surface. While the Yellowstone hotspot is now under the Yellowstone Plateau, it previously helped create the eastern Snake River Plain (to the west of Yellowstone) through a series of huge volcanic eruptions. Although the hotspot’s apparent motion is to the east-northeast, the North American Plate is really moving west-southwest over the stationary hotspot deep underneath.

Building on a growing body of evidence, Mathias Obrebski of the University of California, Berkeley, and his colleagues created the most convincing picture to date of a Yellowstone mantle plume — one that extends from about 621 miles below the surface of the Earth.

Debates have long been waged over whether erupting and shaking in the area over the last few millions of years — and a track marked out by a chain of volcanic calderas along the Yellowstone Snake River Plain in Idaho — could be the work of a column of hot rock rising up from deep within the Earth’s mantle. The mantle is the layer of hot, viscous rock beneath the planet’s crust.

Obrebski’s team used data from a new, dense deployment of seismometers, called the Earthscope USArray, to get a high-resolution image of the elusive mantle, along with information on the unusual structure of the subducting Juan de Fuca slab to its west. The Juan de Fuca plate is a small tectonic plate jammed in between the much larger Pacific and North American plates.

The plume is thought to be more or less stationary, with the North American plate — and the Juan de Fuca subducting beneath it — slowly sliding southwesterly over the plume. So what is now Oregon probably sat where Yellowstone is today about 17 million years ago, baking and breaking over a hot plume of rock. The findings were detailed in the July 22 edition of the journal Geophysical Research Letters.

The source of the Yellowstone hotspot is controversial. Some geoscientists hypothesize that the Yellowstone hotspot is the effect of an interaction between local conditions in the lithosphere and upper mantle convection. Others prefer a deep mantle origin (or mantle plume). Part of the controversy is due to the relatively sudden appearance of the hotspot in the geologic record. Additionally, the Columbia Basalt flows appeared at the same approximate time, causing speculation about their origin.

Interesting2: There is widespread knowledge of airborne creatures taking to the water. Everybody knows about ducks and geese, penguins, and seabirds that dive for their prey. But, there is scant attention for the seaborne creatures that take to the air. Flying fish really do fly. A new study published in the Journal of Experimental Biology takes a look at how these amazing animals do what they do.

Flying fish, from the family of marine fish, Exocoetidae, can remain in the air for over forty seconds and cover distances of 400 meters at speeds of 43 mph. There are about 64 species which all live in oceans at the tropical and subtropical latitudes. There pectoral fins are enlarged, allowing the fish to take flight to escape predators by leaping out of the water. Their "wings" have an aerodynamic shape that can be compared to those of birds.

The study by Haecheon Choi and Hyungmin Park of the Seoul National University in Korea went about to find out how fish can stay aloft. First, they had to catch the fish for his experiments, which proved to be quite difficult. After selecting five similar-sized fish, Park had them dried and stuffed, some with their wings extended as if in flight. These were then taken to the wind tunnel to test their aerodynamics.

Like any aircraft, the fish have a lift-to-drag ratio that is essential to flight. The researchers found that it actually quite good, gliding better than insects and as well as some waterfowl. The fish are not as good at turning, however. They fly best when their wings are parallel to the surface of the water. When the wings were swept back, the flight became more unstable, but that is what is necessary for aquatic aerodynamics.

This makes the flying fish well adapted in both environments. The researchers realized that flying fish always glide just above the surface of the sea, never at a high elevation. Therefore, they tailored some of their wind-tunnel experiments so that the fish was set up near the floor.

They found that the lift-to-drag ratio rose as the elevation became less and less. The fish can go farther by staying closer to the water. The next step for these intrepid researchers is to construct an airplane inspired by the design of the flying fish. Now that would be a sight to see.

Interesting3: From farmers to government officials in charge of efficiently managing Earth’s precious water and energy resources, people all over the world rely on accurate short-term climate forecasts on timescales ranging from a few weeks to a few years to make more informed decisions. But today’s climate forecast systems have limited ability to operate on such timescales. That’s because it’s difficult to realistically represent the complex interactions between Earth’s ocean, atmosphere and land surface in the climate models from which forecasts are developed.

A new report by the National Academy of Sciences looks at the current state of these climate predictions and recommends strategies and best practices for improving them. Duane Waliser, chief Earth scientist at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., was on the 12-member panel that conducted the NOAA-requested study.

Among the report’s key recommendations:

• Continue research to better understand and use information from key sources of climate predictability, and interactions between the ocean and atmosphere, atmosphere and land, as well as volcanic eruptions, greenhouse gases and land use changes.

• Improve the basic building blocks of climate forecasts through better physical climate models, making more sustained physical observations, better incorporating observations into forecast systems, and increasing collaboration between forecast agencies and stakeholders in developing and implementing forecast strategies.

• Adopt best practices such as working more closely with research communities, particularly universities; making data that feed into and come out of forecasts publicly available; minimizing subjective forecast components; and using forecast metrics that better convey to the public the probability aspects of forecasts.

Waliser contributed his expertise in a phenomenon called the Madden-Julian Oscillation that exerts a powerful influence on short-term climate predictions. During this type of climate pattern, unusual variations of clouds, rainfall and large-scale atmospheric circulation move slowly eastward from the tropical Indian Ocean into the Pacific Ocean over the course of weeks, ebbing and flowing like waves in cycles lasting about 40 to 50 days.

This climate pattern typically spans more than half the distance around Earth’s equator. In the disturbed portion of the "wave," air rises, triggering showers and thunderstorms; in the sinking portion, air subsides, inhibiting clouds and rainfall.

Madden-Julian Oscillation events can strongly influence long-term weather patterns and have widespread impacts around the globe. They can help trigger the beginning and end of the Asian and Indian monsoons and influence the development and evolution of El Niño, hurricanes and weather in Earth’s mid-latitudes. Scientists want to incorporate information about the oscillation more accurately into the climate models that agencies around the world use to predict weather and climate.