南極臭氧破洞逾1千萬平方英哩,創新紀錄
NASA and NOAA Announce Ozone Hole is a Double Record Breaker
撰文：Rob Gutro（Goddard Space Flight Center）
--------------------------------------------------------------------------
NASA and NOAA Announce Ozone Hole is a Double Record Breaker
10.19.06
NASA and National Oceanic and Atmospheric Administration (NOAA)
scientists report this year's ozone hole in the polar region of the
Southern Hemisphere has broken records for area and depth.
The ozone layer acts to protect life on Earth by blocking harmful
ultraviolet rays from the sun. The "ozone hole" is a severe depletion
of the ozone layer high above Antarctica. It is primarily caused by
human-produced compounds that release chlorine and bromine gases in
the stratosphere.
http://www.nasa.gov/centers/goddard/images/content/160657main_OZONE_large.jpg
Image: From September 21-30, 2006 the average area of the ozone
hole was the largest ever observed, at 10.6 million square miles. This
image, from Sept. 24, the Antarctic ozone hole was equal to the record
single-day largest area of 11.4 million square miles, reached on Sept. 9,
2000. Satellite instruments monitor the ozone layer, and we use their
data to create the images that depict the amount of ozone. The blue and
purple colors are where there is the least ozone, and the greens, yellows,
and reds are where there is more ozone. Credit: NASA
"From September 21 to 30, the average area of the ozone hole was the
largest ever observed, at 10.6 million square miles," said Paul Newman,
atmospheric scientist at NASA's Goddard Space Flight Center, Greenbelt,
Md. If the stratospheric weather conditions had been normal, the ozone
hole would be expected to reach a size of about 8.9 to 9.3 million
square miles, about the surface area of North America.
The Ozone Monitoring Instrument on NASA's Aura satellite measures the
total amount of ozone from the ground to the upper atmosphere over the
entire Antarctic continent. This instrument observed a low value of 85
Dobson Units (DU) on Oct. 8, in a region over the East Antarctic ice
sheet. Dobson Units are a measure of ozone amounts above a fixed point
in the atmosphere. The Ozone Monitoring Instrument was developed by
the Netherlands' Agency for Aerospace Programs, Delft, The Netherlands,
and the Finnish Meteorological Institute, Helsinki, Finland.
Scientists from NOAA's Earth System Research Laboratory in Boulder,
Colo., use balloon-borne instruments to measure ozone directly over the
South Pole. By Oct. 9, the total column ozone had plunged to 93 DU from
approximately 300 DU in mid-July. More importantly, nearly all of the
ozone in the layer between eight and 13 miles above the Earth's surface
had been destroyed. In this critical layer, the instrument measured a
record low of only 1.2 DU., having rapidly plunged from an average non-
hole reading of 125 DU in July and August.
"These numbers mean the ozone is virtually gone in this layer of the
atmosphere," said David Hofmann, director of the Global Monitoring
Division at the NOAA Earth System Research Laboratory. "The depleted
layer has an unusual vertical extent this year, so it appears that the
2006 ozone hole will go down as a record-setter."
Observations by Aura's Microwave Limb Sounder show extremely high
levels of ozone destroying chlorine chemicals in the lower stratosphere (
approximately 12.4 miles high). These high chlorine values covered the
entire Antarctic region in mid to late September. The high chlorine
levels were accompanied by extremely low values of ozone.
http://tinyurl.com/y69fp8
Image: The ozone hole of 2006 is the most severe ozone hole (least amount
of ozone) observed to date. NASA's Aura satellite observed a low value
of 85 Dobson Units (DU) on Oct. 8 in a region over the East Antarctic
ice sheet. Dobson Units are a measure of ozone amounts above a fixed
point in the atmosphere. This severe ozone hole resulted from the very
high ozone depleting substance levels and the record cold conditions
in the Antarctic stratosphere. Credit: NASA
The temperature of the Antarctic stratosphere causes the severity of
the ozone hole to vary from year to year. Colder than average tempe-
ratures result in larger and deeper ozone holes, while warmer tempe-
ratures lead to smaller ones. The NOAA National Centers for Environmental
Prediction (NCEP) provided analyses of satellite and balloon stratospheric
temperature observations. The temperature readings from NOAA satellites
and balloons during late-September 2006 showed the lower stratosphere
at the rim of Antarctica was approximately nine degrees Fahrenheit
colder than average, increasing the size of this year's ozone hole
by 1.2 to 1.5 million square miles.
The Antarctic stratosphere warms by the return of sunlight at the end
of the polar winter and by large-scale weather systems (planetary-scale
waves) that form in the troposphere and move upward into the stratosphere.
During the 2006 Antarctic winter and spring, these planetary-scale
wave systems were relatively weak, causing the stratosphere to be colder
than average.
As a result of the Montreal Protocol and its amendments, the concentra-
tions of ozone-depleting substances in the lower atmosphere (troposphere)
peaked around 1995 and are decreasing in both the troposphere and
stratosphere. It is estimated these gases reached peak levels in the
Antarctica stratosphere in 2001. However, these ozone-depleting substances
typically have very long lifetimes in the atmosphere (more than 40 years).
As a result of this slow decline, the ozone hole is estimated to
annually very slowly decrease in area by about 0.1 to 0.2 percent for
the next five to 10 years. This slow decrease is masked by large year-
to-year variations caused by Antarctic stratosphere weather fluctuations.
The recently completed 2006 World Meteorological Organization/United
Nations Environment Programme Scientific Assessment of Ozone Depletion
concluded the ozone hole recovery would be masked by annual variability
for the near future and the ozone hole would fully recover in appro-
ximately 2065.
"We now have the largest ozone hole on record for this time of year,"
said Craig Long of NCEP. As the sun rises higher in the sky during
October and November, this unusually large and persistent area may
allow much more ultraviolet light than usual to reach Earth's surface
in the southern latitudes.
--------------------------------------------------------------------------
NASA and NOAA Announce Antarctic Ozone Hole Is a Record Breaker
NASA and National Oceanic and Atmospheric Administration (NOAA) scientists
report this year's ozone hole in the polar region of the Southern
Hemisphere has broken records for area and depth.
The ozone layer acts to protect life on Earth by blocking harmful
ultraviolet rays from the sun. The "ozone hole" is a severe depletion
of the ozone layer high above Antarctica. It is primarily caused by
human-produced compounds that release chlorine and bromine gases in
the stratosphere.
"From September 21 to 30, the average area of the ozone hole was the
largest ever observed, at 10.6 million square miles," said Paul Newman,
atmospheric scientist at NASA's Goddard Space Flight Center, Greenbelt,
Md. If the stratospheric weather conditions had been normal, the ozone
hole would be expected to reach a size of about 8.9 to 9.3 million square
miles, about the surface area of North America.
The Ozone Monitoring Instrument on NASA's Aura satellite measures the
total amount of ozone from the ground to the upper atmosphere over the
entire Antarctic continent. This instrument observed a low value of 85
Dobson Units (DU) on Oct. 8, in a region over the East Antarctic ice
sheet. Dobson Units are a measure of ozone amounts above a fixed point
in the atmosphere. The Ozone Monitoring Instrument was developed by the
Netherlands' Agency for Aerospace Programs, Delft, The Netherlands, and
the Finnish Meteorological Institute, Helsinki, Finland.
Scientists from NOAA's Earth System Research Laboratory in Boulder,
Colo., use balloon-borne instruments to measure ozone directly over
the South Pole. By Oct. 9, the total column ozone had plunged to 93
DU from approximately 300 DU in mid-July. More importantly, nearly
all of the ozone in the layer between eight and 13 miles above the
Earth's surface had been destroyed. In this critical layer, the
instrument measured a record low of only 1.2 DU., having rapidly
plunged from an average non-hole reading of 125 DU in July and August.
"These numbers mean the ozone is virtually gone in this layer of the
atmosphere," said David Hofmann, director of the Global Monitoring
Division at the NOAA Earth System Research Laboratory. "The depleted
layer has an unusual vertical extent this year, so it appears that the
2006 ozone hole will go down as a record-setter."
Observations by Aura's Microwave Limb Sounder show extremely high levels
of ozone destroying chlorine chemicals in the lower stratosphere (
approximately 12.4 miles high). These high chlorine values covered the
entire Antarctic region in mid to late September. The high chlorine
levels were accompanied by extremely low values of ozone.
The temperature of the Antarctic stratosphere causes the severity of
the ozone hole to vary from year to year. Colder than average temper-
atures result in larger and deeper ozone holes, while warmer temperatures
lead to smaller ones. The NOAA National Centers for Environmental
Prediction (NCEP) provided analyses of satellite and balloon strato-
spheric temperature observations. The temperature readings from NOAA
satellites and balloons during late-September 2006 showed the lower
stratosphere at the rim of Antarctica was approximately nine degrees
Fahrenheit colder than average, increasing the size of this year's
ozone hole by 1.2 to 1.5 million square miles.
The Antarctic stratosphere warms by the return of sunlight at the end
of the polar winter and by large-scale weather systems (planetary-scale
waves) that form in the troposphere and move upward into the stratosphere.
During the 2006 Antarctic winter and spring, these planetary-scale wave
systems were relatively weak, causing the stratosphere to be colder than
average.
As a result of the Montreal Protocol and its amendments, the concen-
trations of ozone-depleting substances in the lower atmosphere (
troposphere) peaked around 1995 and are decreasing in both the
troposphere and stratosphere. It is estimated these gases reached peak
levels in the Antarctica stratosphere in 2001. However, these ozone-
depleting substances typically have very long lifetimes in the atmo-
sphere (more than 40 years).
As a result of this slow decline, the ozone hole is estimated to
annually very slowly decrease in area by about 0.1 to 0.2 percent for
the next five to 10 years. This slow decrease is masked by large year-
to-year variations caused by Antarctic stratosphere weather fluctuations.
The recently completed 2006 World Meteorological Organization/United
Nations Environment Programme Scientific Assessment of Ozone Depletion
concluded the ozone hole recovery would be masked by annual variability
for the near future and the ozone hole would fully recover in approxi-
mately 2065.
"We now have the largest ozone hole on record," said Craig Long of
NCEP. As the sun rises higher in the sky during October and November,
this unusually large and persistent area may allow much more ultraviolet
light than usual to reach Earth's surface in the southern latitudes.
For information and images about NASA's ozone research, visit:
www.nasa.gov/vision/earth/lookingatearth/ozone_record.html
--------------------------------------------------------------------------
Antarctic ozone hole biggest on record, U.S. reports
WASHINGTON (Reuters) - This year's ozone hole over Antarctica is
bigger and deeper than any other on record, U.S. scientists reported
on Thursday.
http://tinyurl.com/yn5xv4 [Image]
This image of the Antarctic ozone hole, taken September 24, 2006, uses
blue and purple colors to show where there is the least ozone, and
greens, yellows, and reds to highlight where there is more ozone.
Image released by NASA on October 19, 2006. REUTERS/NASA/Handout
The ozone layer shields Earth from the sun's harmful ultraviolet rays,
and the layer thins out over the South Pole each year, primarily because
human-made compounds release ozone-eating chlorine and bromine gases
into the stratosphere.
"From September 21 to 30, the average area of the ozone hole was the
largest ever observed, at 10.6 million square miles ," said Paul Newman
of NASA's Goddard Space Flight Center outside Washington.
If the stratospheric weather conditions had been normal, the ozone
hole would be expected to reach a size of about 8.9 million to 9.3
million square miles, about the surface area of North America, NASA
said in a statement.
Scientists measure the total amount of ozone from the ground to the
upper atmosphere in Dobson Units, and a NASA satellite detected a low
level of 85 Dobson Units on October 8 of the East Antarctic ice sheet.
Scientists from the National Oceanic and Atmospheric Administration
used balloon-borne instruments to measure ozone right over the South
Pole, and by October 9 the total ozone in a column from the ground to
the upper atmosphere had dropped to 93 DU from about 300 DU in mid-July.
Temperature variations in the Antarctic stratosphere causes the severity
of the ozone hole to vary from year to year. Colder temperatures result
in larger and deeper ozone holes, while warmer temperatures lead to
smaller ones. This year, the lower stratosphere was about 9 degrees
Fahrenheit (5 degrees Celsius) cooler than average.
Concentrations of ozone-depleting chemicals in the lower atmosphere
have been declining since 1995, and scientists estimate the ozone hole
will be completely recovered by about 2065.
c Reuters 2006. All Rights Reserved.
--------------------------------------------------------------------------
NASA:南極臭氧破洞逾1千萬平方英哩,創新紀錄
來源：路透社
路透華盛頓電---美國科學家周四報告，今年南極上空的臭氧破洞是
史上最大也最深的。
臭氧層替地球遮擋太陽具有傷害性的紫外線，但南極上方的臭氧層卻
一年比一年薄，主要是因為人造化學合成藥劑釋出侵蝕臭氧的氯氣和
溴氣並進入平流層所致。
「從9月21日到30日，臭氧破洞的平均區域是我們所觀察過最大的，
達1,060萬平方英哩，」美國太空總署(NASA)位於華盛頓外圍的戈達
德太空飛行中心(Goddard Space Flight Center)的紐曼(Paul Newma
n)說。
如果平流層的天氣狀況很正常，則臭氧破洞的大小料為890萬至930萬
平方英哩，與北美的地表差不多大，NASA在聲明中說。
科學家使用達伯遜單位(Dobson Units)測量從地上到大氣較高部分的
臭氧總量，而NASA衛星於10月8日在南極東部的冰原偵測到的臭氧量
僅達低水準的85 DU。
美國國家海洋及大氣管理局的科學家使用氣球運送的儀器到南極的上
空對臭氧進行測量，而在10月9日，從地上到大氣較上方的臭氧柱總
量為93 DU，低於7月中的300 DU左右。
南極平流層的氣溫變化會造成臭氧破洞的嚴重程度年年不同。冷一點
的氣溫會導致較大且深的破洞，而在暖一點的氣溫下，破洞則會變小
。今年，平流層較低部份的氣溫約為攝氏五度，較平均溫度為低。
自1995年以來，大氣較低部份減少臭氧量的化學藥劑濃度逐漸降低，
而科學家估計，臭氧破洞在2065年左右會完全復原。(完)
--編譯 林雨蒨;審校 鄒衡天
--------------------------------------------------------------------------
來源：
NASA
http://www.nasa.gov/centers/goddard/news/topstory/2006/ozone_record_prt.htm
http://www.nasa.gov/home/hqnews/2006/oct/HQ_06338_Fianl_Ozone_2006_prt.htm
REUTERS
http://tinyurl.com/yyz8gk
REUTERS(yahoo.NEWS)
http://tw.news.yahoo.com/article/url/d/a/061021/16/5j38.html
--
╔═══╮╭═══╮╔═══╮╔═══╮╔═══╗╔═══╮╔═══╗
║ ║║ ║║ ║║ ║║ ║║ ║║ ║
║ ║║ ║║ ║║ ║║ ║║ ║║ ║
║ ║║ ═ ║║ ═ ╯║ ═ ║║ ═╣║ ═ ╯╚═╗╔╝
║ ║║║║ ║║ ╔╮║║ ═ ║║ ═╣║ ╔╮║ ║║
╚═╝╝╝╰═══╯╚═╝╚╝╚═══╯╚═══╝╚═╝╚╝ ╚╝
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 140.122.150.47