April 13, 1999
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Editor: Cheryl Dybus
Contents of this News Tip:
A network of ground-based instruments that detects the amount of ultraviolet
(UV) radiation emitted by the sun and reaching Earth's surface, is now
operating. The network will help determine how the amount of UV light
may be changing. The network, set up by the U.S. Global Change Research
Program and funded by the National Science Foundation (NSF) and other
federal agencies, will provide information about the flux of UV radiation
at Earth's surface for atmospheric science studies, and for research on
UV human health and ecological effects.
The network uses three types of
instruments -- broadband radiometers, narrow-band filter instruments,
and spectrophotometers -- and has a total of 66 instruments at 55 locations.
The need for UV data is a result of the recognition that ozone depletion
induced by human activity could lead to increased amounts of UV radiation
reaching Earth's surface, especially if other atmospheric parameters,
such as cloudiness and aerosol loading, remain unchanged. Atmospheric
observations have shown conclusively that total ozone amounts have been
decreasing over much of Earth's surface, in response to increasing concentrations
of industrially produced halogens in the atmosphere. Thus far, however,
the ground-based data record does not confirm long-term surface UV increases.
The new network, scientists hope, will shed light on whether the amount
of UV light reaching the planet's surface is in fact steadily increasing.
[Cheryl Dybas]
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NSF's grant statistics for fiscal 1998, which incorporate new merit
review criteria as of the start of that fiscal year, remain largely static
when compared to recent history. The funding rate for proposals during
the year remained unchanged from the previous year, at 33 percent. Meanwhile,
award size increased somewhat while the number of proposals received decreased
slightly.
The statistics are included in the annual report on NSF's merit review
system, presented recently to the National Science Board at its March
meeting. During fiscal 1998, NSF received about 28,300 proposals - a slight
decrease from the roughly 30,000 received annually in the previous five
years. NSF funded about 9,300 of those proposals, or about one-third,
which is consistent with recent history and is equal to a five-year maximum
reached in 1994.
Award size increased to an average of $105,400 and a mean of $61,666.
Most 1998 proposals were reviewed by a combination of mail and panel methods.
NSF received a total of 244,000 reviews last year, for an average of 8.6
reviews per proposal.
[Mary Hanson]
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Tropical coral reefs could be directly threatened by the buildup of
atmospheric carbon dioxide (CO2) entering the oceans, and some reefs may
already be declining, say scientists. According to Joan Kleypas of the
National Center for Atmospheric Research (NCAR), "I believe that these
findings represent the first evidence of a direct negative impact of increased
CO2 on a marine ecosystem." NSF is NCAR's primary sponsor.
The team's findings apply primarily to coral reefs located in surface
waters within 35 degrees north and 35 degrees south of the Equator. However,
the authors predict that reefs in greatest danger are those where the
production and destruction of calcium carbonate are closely balanced.
These include some higher latitude reefs, such as: those off Bermuda;
those in areas where colder, deeper waters rise to the surface, like those
off the Galapagos Islands; or many reefs already stressed by human
activity.
A coral reef is the accumulation of calcium carbonate produced by the
corals and other calcium-secreting organisms, such as coralline algae.
If calcium production declines, coral and algal skeletons will weaken
and reef building may slow or stop. The reef then becomes more vulnerable
to erosion. Ongoing calcium production depends on the saturation state
of calcium carbonate in surrounding surface waters. This saturation state
declines as CO2 enters tropical surface waters.
This is one of the first
studies to examine how CO2 increases may affect the chemistry and biology
of ocean ecosystems. [Cheryl Dybas] Top of Page
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