Tracking the pollution amid the remote

March 1, 2021 0 Comments

first_img In for landing Flying around weather systems as the crew prepared to make the final landing of HIPPO-4 in Colorado, after four weeks and 30,000 miles of travel. Photo by Jasna Pittman Sunset Sunset over the subtropical Pacific while flying from Saipan to Midway Atoll in July 2011. Photo by Bruce Daube Volcanic Flying over volcanoes in the Aleutian Islands of Alaska in July 2011. Photo by Bruce Daube Fractured Fractured sea ice just 70 degrees north of the Alaskan coast in June 2011. Photo by Jasna Pittman Leaving on a jet plane Sunset over the equatorial Pacific while flying from Kona, Hawaii, to Rarotonga, Cook Islands, in June 2011. Photo by Bruce Daube A new day Sunrise over the subtropical Pacific as the crew flew from Midway Atoll to Anchorage, Alaska, in July 2011. Photo by Jasna Pittman HIAPER Pole-to-Pole Observations In September, a multi-institution team led by Harvard Professor Steven Wofsy completed a three-year effort to fill in the gaps of our knowledge about the atmosphere by measuring chemicals and particles during a series of pole to pole flights. Photo by Kris Snibbe/Harvard Staff Photographer Coal factory Sampling of emissions from anthropogenic activity over the western U.S. Photo by Jasna Pittman Polar express Arctic waters Jasna Pittman examining real-time measurements of various chemical species while the aircraft was flying over Arctic waters in March 2010. Photo by Bruce Daube Photos by Bruce Daube, Jasna Pittman, and Kris Snibbe Jasna Pittman expected to be surprised by new findings as she traveled around the world measuring gases and particles in a three-year effort to understand how the atmosphere works.She didn’t expect to be shocked by what she already knew.“Alaska is incredible, absolutely breathtaking. We were there in the wintertime, so you could see all the mountains covered in snow, beautiful blue skies,” said Pittman, a research associate in atmospheric sciences at Harvard. “You look out far away, and you see this layer of haze.”It has long been known that pollution is blown into Alaska’s skies from Europe and Asia, but Pittman and other scientists who participated in a three-year project to gather data on the Earth’s atmosphere said their prior knowledge didn’t lessen the impact of seeing the pollution firsthand.“It looked like Los Angeles,” said Steven Wofsy, the project’s principal investigator and the Abbott Lawrence Rotch Professor of Atmospheric and Environmental Science at Harvard. “It was a smoggy haze, thick enough that you couldn’t see features on the ground. People knew it was there, but it was much bigger than we thought.”Wofsy’s team, which included Pittman, engineer Bruce Daube, postdoctoral fellow Eric Kort, and graduate student Gregory Santoni, conducted five globe-spanning flights in a small jet crammed with high-tech instruments. Along the way, they measured gases and particles from pole to pole on roller-coaster flights that rose from just above sea level to 48,000 feet. Their project, called HIPPO, which stands for HIAPER Pole-to-Pole Observations, was run under the auspices of the National Center for Atmospheric Research and included scientists from the University of Miami, Princeton University, the National Oceanic and Atmospheric Administration, and Scripps Institution of Oceanography.Wofsy described the project as something of a dream come true. Although scientists routinely measure the atmosphere’s composition from ground-based stations and peek at it from orbiting satellites, they have to infer from those measurements what is going on high in the atmosphere.The last time a similar atmospheric sampling operation was conducted was in 1977 and 1978, Wofsy said. With the climate change crisis prompting government action to fight global warming, the computer models on which climate predictions rely need data like this to ensure their accuracy.HIPPO scientists measured 80 chemicals, including the greenhouse gases carbon dioxide, methane, and nitrous oxide, as well as the byproducts of industrial burning, carbon monoxide and particles of black carbon. The latter two were present in surprisingly high levels far from human habitation over the Arctic.“You’re flying and looking at data in real time. … You look at concentrations of carbon monoxide; they just spike.  It was really mind-boggling. There shouldn’t be this much carbon monoxide, certainly not over Alaska and certainly not at 20,000 feet,” Pittman said. “It was almost sad to see. It’s this pristine environment. It’s so white, it’s so clear, so beautiful.”HIPPO scientists flew in a converted Gulfstream V, stuffed with instruments and owned by the National Science Foundation. Though most of the instrument setup and data download occurred before and after the flight, Kort and Santoni were called on to repair malfunctioning equipment in midflight to avoid missing key data.The five HIPPO flight series had a different mix of personnel from Wofsy’s group and those of other scientists involved. Each series of flights took off from the plane’s home base in Colorado, flew up to Alaska, and over the top of the world. It traversed the Pacific to a turnaround in New Zealand before taking a different path back. The three-week flights were timed so that samples were taken during different seasons to give scientists information on how the atmosphere changes as the Earth cycles through its annual rhythms.In between preparing for each day’s flying and handling the enormous amount of data generated afterward, researchers witnessed the Earth’s moods, watching sunsets and moonrises, sunny skies and storms, manmade pollution and even the occasional rainbow — all ample reward for the epic jet lag that came with the territory.At times, nature provided a dramatic show of the physical effects they were studying. Wofsy recalled one flight over the Beaufort Sea, which was clear of ice. The researchers flew near a robotic boat that was recording water temperatures warm enough that steam was flowing into the cold air.“You could see the heat and water vapor being transferred into the atmosphere,” Wofsy said. “You didn’t need a model to see it.”The last flight landed in September, and research groups are already inquiring about the data: 40 measurements every second, combined with aircraft information such as location, altitude, and outside air temperature.Several aspects stood out to Wofsy even as the raw numbers were arriving. The data raised questions about the Southern Ocean’s ability to remove and store atmospheric carbon and also showed the presence of large amounts of nitrous oxide — a potent greenhouse gas — in the air above the tropics. That indicates not only that there are more greenhouse gases there than expected, but also that scientists don’t really understand how the tropical atmosphere works.Another finding involves the release of methane as the Arctic warms. Scientists have been concerned that the region’s frozen ground, called permafrost, will melt with higher temperatures and release methane when previously frozen organic material decomposes. Methane, like carbon dioxide, is a greenhouse gas, so significant releases will exacerbate the globe’s warming.The project measured that theorized methane emission, but Wofsy said the source was not always the permafrost. Instead, flights detected significant emissions from the ice-free Arctic Ocean. While the emissions’ source remains unclear — both surface waters and sediments are suspect — what is known is that current models don’t account for these emissions.“This is in direct relation to sea ice cover,” Wofsy said. “With continuous ice cover, you don’t see this.” Gygis alba One of many white terns (Gygis alba) spotted during a 30-hour visit to Midway Atoll in the northern central Pacific in July 2011. Photo by Jasna Pittman Working hard Eric Kort (top left) and Bruce Daube connecting the inlet that provides ambient air to one of the Harvard instruments that measures carbon dioxide. Photo by Jasna Pittman What a view Typical view from the window of the Gulfstream-V while traversing the equatorial Pacific. Photo by Jasna Pittmanlast_img read more

Their favorite things

March 1, 2021 0 Comments

first_img Strong yield for the Class of 2023 Making themselves at home in Harvard Yard Harvard College admits 1,950 to Class of ’23 College’s Financial Aid Initiative continues to bolster interest Moving in is the easy part. The challenge is making Harvard feel like home. To help with that, many students bring with them mementos that say a bit about who they are and where they’re from. The Gazette asked some first-years for a peek inside their suitcases.,Relatedcenter_img Smiles, handshakes, and even a little hair styling as first-years move in The Daily Gazette Sign up for daily emails to get the latest Harvard news. Grants will ease families’ financial burden substantially; community service a draw last_img read more

Rosicky to remain with Gunners

September 20, 2020 0 Comments

first_img Asked if he expected Rosicky to stay, Wenger replied: “Yes.” The Arsenal manager added: “We have taken up the option (of a one-year contract extension).” Arsenal are likely to strengthen the squad in the summer, with Chelsea goalkeeper Petr Cech a reported target. However, it remains to be seen whether the Blues will allow the veteran stopper to join one of their title rivals. The close relationship between Cech and Rosicky is also said to be a factor in any potential £10million deal. Wenger, however, insisted such issues should play no part in any transfer. “Tomas Rosicky is not involved in the transfer market at all, he will be with us next season and we do not use the players for that,” the Arsenal boss said. “Most of the time it is the players who want to join you who come in. Sometimes they might call each other, but we do not get the players to interfere with that.” Czech midfielder Tomas Rosicky is set to stay at Arsenal next season, manager Arsene Wenger has confirmed. The 34-year-old has been on the fringes of the squad this season, making only five starts in the Barclays Premier League. However, Wenger insisted the former Borussia Dortmund playmaker remained integral to his plans for 2015-16. Press Association Arsenal will be out to sign off from their Premier League season with a return to winning ways against West Brom on Sunday, and so take some momentum into the FA Cup final. Wenger’s men laboured through a goalless draw at home to Sunderland on Wednesday night, which was enough to keep the Mackems up and all but secured third place for the Gunners. “We have fought very hard to directly qualify for the Champions League and we want to get over the line and finish the job, which we couldn’t do on Wednesday night. We want to do it in a convincing way on Sunday,” said Wenger, whose side have not scored at home for three games. Arsenal forward Danny Welbeck has been troubled a painful knee injury which could put him in a race against time to be fit for both the FA Cup final against Aston Villa on May 30 and also international duty with England in June. “Danny will go out today for the first time, we have to wait for the response to that to know if he responds in a positive way. He could be fit very quickly,” said Wenger. “There is a good chance that he will be available for England, however it is difficult to know. “But certainly if he is not available for the FA Cup final, I can’t see him being competitive enough for England.” Midfielder Alex Oxlade-Chamberlain was not included in the England squad named on Thursday as he continues to recover from first an inflamed groin and then hamstring problem which sidelined him since early March. “It is not impossible (to make the FA Cup final) because he starts full training today. We will see how he responds to that,” said Wenger. “The difference (in not being selected for England) is that Alex Oxlade-Chamberlain has not played in any competition for a long time. That lack of competition takes some time to come back to a good competitive level. “I didn’t tell him (England manager Roy Hodgson) not to pick Oxlade-Chamberlain. He has looked when he played his last game and has then decided.” Wenger added: “Danny Welbeck is not out for a long time and he has nothing at all on any scan, just bone bruising on his knee, that is just the pain that will decide if he is fit or not.” last_img read more