Forecast: Hotter East Coast Summers …
... and other recent findings by WHOI researchers
Forecast: Hotter Summers
If greenhouse gas emissions continue to rise at current rates, average summertime high temperatures in the eastern United States could rise 10°F by 2080, and soar to more than 100°F in Chicago, Washington, and Atlanta, according to a study by NASA and WHOI researchers published April 2007 in the Journal of Climate.
The team fed results from a computer model that simulates future global climate change into a separate weather prediction model that forecasts summer temperature variability in the eastern U.S. The global model alone failed to account for periods without enough rainfall on the East Coast, which cause temperatures to rise dramatically, said Rick Healy, an information systems specialist at WHOI and co-author of the study. See more on the study here.
A rare chance to examine a rare turtle
A panoply of uncommon stories and specimens, from shrimp to whales, passes through Woods Hole Oceanographic Institution’s Computerized Scanning and Imaging Facility. Another unusual subject arrived in May 2007, when a team of specialists from several institutions and agencies used the facility to conduct a necropsy on a 900-pound leatherback turtle.
The leatherback, an endangered species, was inadvertently caught in April off Jupiter, Florida, during a longline survey of Atlantic shark carried out every two to three years by the National Oceanic and Atmospheric Administration Fisheries Service. The turtle was kept for a required 24-hour observation period before being confirmed dead, said Teri Frady of the NOAA Northeast Marine Fisheries Center. NOAA anticipates and accounts for this and other incidental catches when, as the federal Endangered Species Act mandates, it evaluates the total impact of fisheries on turtle populations.
The unintentional catch did have a positive side: It presented a rare opportunity to learn more about this species. With funding from NOAA, Jeanette Wyneken (in white), an expert on turtle physiology from Florida Atlantic University, came to WHOI to lead the necropsy. It included WHOI biologist Darlene Ketten (in blue) and WHOI staff using the high-resolution medical scanner to create precise three-dimensional visualizations of the leatherback’s internal structure, which are impossible to obtain by dissection.
New Orleans toxic gumbo
When New Orleans’ levees broke after Hurricane Katrina, officials feared Lake Pontchartrain might be infiltrated with a “toxic gumbo” of water, polluted sediments, and sewage. Weeks after the flood, scientists from several U.S. Centers for Oceans and Human Health, including WHOI biologist Rebecca Gast, mobilized to sample mud and waters around the lake, looking for disease-causing microbes.
In the May 2007 issue of the journal Proceedings of the National Academy of Sciences, they reported that the influence of contaminated floodwaters on Lake Pontchartrain was relatively short-lived, limited to coastal areas, and did not leave a lasting contamination or disease problem. See more about Rebecca Gast’s work.
Scientific Ice Capades
In the middle of a December, 2006 night, researchers use a specialized bulldozer (aka the “Piston Bully”) to pull a shipping container mounted on skis (the “Thunder Sled”) across the ice covering Antarctica’s Ross Sea.
Scientists had used these same vehicles the previous October to tow mooring equipment, ice melting equipment, food, and camping supplies from McMurdo Station on Antarctica 18 miles onto the ice shelf through whiteout conditions and air temperatures ranging from 5° to -40°F (-15° to -40°C). The trip took four hours. The team melted and cut a 2-foot-diameter hole through sea ice that was 23 feet thick to install a mooring, designed by WHOI Senior Research Specialist Richard Limeburner. It measured ocean currents swirling beneath the ice shelfin advance of deploying a drilling platform on the ice later this year. The apparatus will extend through the ice and 1,700 feet of ocean and then drill about ¾ of a mile into the continental shelf below the seafloor.
The work was part of the ANDRILL project, involving hundreds of researchers from several nations, that aims to obtain sediments (hard to come by on an ice-covered continent) that provide a record reaching back 17 million years of past climate and ocean conditions around Antarctica, as well as the continent’s geological history.
A Conversation of Narwhals
Individual narwhals, the Arctic whales with spiraled unicorn-like tusks, can make individual sounds that may help other narwhals recognize them or help them reunite with their group. Ari Shapiro, a biological oceanography graduate student in MIT/WHOI Joint Program, and colleagues used digital-recording devices temporarily suction-cupped to two narwhals in Admiralty Bay on Baffin Island, Canada.
“For the first time, we could really ‘ride’ with the animals as they were vocalizing and as they were moving,” said Shapiro, who reported the findings in the September 2006 issue of the Journal of the Acoustical Society of America.
Mercury in groundwater
WHOI scientists have found that a surprisingly substantial amount of mercury enters the ocean from groundwater flowing out of underground aquifers near the coast.
“This pathway for delivering nutrients and contaminants into the ocean has long been overlooked and ignored because it was difficult to quantify,” said WHOI marine chemist Matt Charette, whose lab has advanced methods to detect mercury flowing out of aquifers.
Charette and Sharon Bone, a former undergraduate summer student fellow at WHOI, published their findings May 2007 in the journal Environmental Science and Technology.
Ancient bridge reconstruction
Researchers have found evidence that the land bridge between Alaska and Siberiabelieved to be the major route for human migration from Asia to the Americasmay have been cut off about 1,000 years earlier than widely thought.
Working aboard the Coast Guard Cutter Healy (as seen in the photo) and extracting the longest piston core ever of seafloor sediments in the Arctic Ocean, WHOI paleoceanographer Lloyd Keigwin and colleagues analyzed and dated clues indicating that the Bering Strait flooded into the Arctic Ocean about 11,000 years ago.
The finding, reported in the October 2006 issue of Geology, offers a key milepost for archaeologists reconstructing human history.