2 . A study published on May 24 offers an explanation for a mysterious (神秘的) and sometimes deadly weather pattern in which the jet stream (急流), the global air currents that circle the Earth, wanders over a region. “Much like highways. The jet stream has a limit,” researchers said, “and when it was beyond its limit, blockages (拥堵)form that are remarkably similar to traffic jams—and climate forecasters can use the same math to model them both.”
The deadly 2003 European heat wave, California’s 2014 drought and the swing of Superstorm Sandy in 2012 that surprised forecasters—all of these were caused by a weather phenomenon known as “blocking”, in which the jet stream wanders, stopping weather systems from moving eastward. Scientists have known about it for decades, almost as long as they’ve known about the jet stream—first discovered by pioneering University of Chicago meteorologist (气象学家)Carl-Gustaf Rossby, in fact—but no one had a good explanation for why it happens.
“Blocking is very difficult to forecast, in large part because there was no clear theory about when it forms and why,” said study coauthor Noboru Nakamura, a professor in the Department of the Geophysical Sciences.
Nakamura and then-graduate student Clare S. Y. Huang were studying the jet stream, trying to determine a clear set of measurements for blocking in order to better analyze the phenomenon. One of their new metrics (度量)was a term that measured the routine of the jet stream. Looking over the math. Nakamura realized that the result was nearly the same to one designed decades ago by transportation engineers trying to describe traffic jams.
Much like car traffic, movement slows when multiple highways come together and the speed of the jet stream is reduced due to mountains or coasts.
1. What is the similarity between jet stream and traffic jams?
A.Both of them are mysterious. |
B.Both of them can be predicted. |
C.Blockages can be solved in the same way. |
D.Blockages form when they are beyond a certain limit. |
2. What can be inferred from the passage?
A.Nakamura helped explain the blocking phenomenon of jet stream. |
B.Carl-Gustaf Rossby discovered the cause of the jet stream. |
C.Scientists have known the swing of Superstorm Sandy in 2012 before it happened. |
D.Blocking phenomenon of jet stream happened when multiple highways come together. |
3. What is the best title for the passage?
A.Some Great Scientists in a Study |
B.A New Explanation for Traffic Jam |
C.Some New Discoveries for Traffic Jam |
D.A New Theory Finds “Traffic Jams” in Jet Stream |
4. Where does this passage probably come from?
A.A science magazine. | B.A guidebook. |
C.A science fiction. | D.An advertisement |