[One-Minute World News] from [BBC NEWS]
[bbc.co.uk > Science & Environment]
Page last updated at 09:46 GMT, Friday, 11 June 2010 10:46 UK
Japan unfurls solar sail in orbit
｛日本、軌道上で太陽光を受ける帆を展開｝
{An image of the deployment is sent back to Earth}
Japanese scientists are celebrating the successful deployment of their solar sail Ikaros.
｛日本の科学者、宇宙ヨット「イカロス」の帆の展開の成功を祝う｝
The 200-sq-m (2,100-sq-ft) membrane is attached to a small disc-shaped spacecraft that was put in orbit last month by an H-IIA rocket.
Ikaros will demonstrate the principle of using sunlight as a simple and efficient means of propulsion.
The technique has long been touted as a way of moving spacecraft around the Solar System using no chemical fuels.
The mission team will be watching to see if Ikaros produces a measurable acceleration, and how well its systems are able to steer the craft through space.
The Japan Aerospace Exploration Agency (Jaxa) said in a statement that its scientists and engineers had begun to deploy the solar sail on 3 June (JST). On 10 June, Jaxa said, confirmation was received that the sail had expanded successfully and was generating power through the thin film solar cells embedded in the membrane
The deployment occurred about seven million km from Earth.
Ikaros was a piggy-back payload to Japan's Venus orbiter Akatsuki. The pair were boosted in to space on 21 May (JST) from the Tanegashima Space Center.
Akatsuki will arrive at Venus in December. Key goals include finding definitive evidence for lightning and for active volcanoes.
{{SAILING TO VENUS - HOW IKAROS UNFURLS ITS SOLAR SAIL}
(1) For the deployment, the disc-shaped Ikaros spacecraft was first spun up
(2) The four weighted corners of the sail were then released and flew outwards
(3) Finally, the packed sail membrane was released and pulled flat by the rotating tips}
[bbc.co.uk > Science & Environment]
Page last updated at 08:16 GMT, Friday, 11 June 2010 09:16 UK
By Mark Kinver
Science and environment reporter, BBC News
Himalayan climate impacts 'cannot be generalised'
｛ヒマラヤの気候温暖化の影響は総括的に述べれない｝
{Mountain glaciers provide vital lifeblood for some of Asia's major rivers}
｛アジアの大河には、山の氷河が極めて重要な活力源になっているものがある｝
Melting glaciers in the Himalayas will have varying impacts on the region's five major river basins, a study says.
｛調査報告書によると、ヒマヤラの氷山の溶解が５大河川流域に種々の影響を及ぼしている｝
Changes to the flow of meltwater as a result of global warming is likely to have a "severe" impact on food security in some area, say scientists.
Yet people living elsewhere are likely to see food productivity increase, they added in a paper published in Science.
Overall, the food security of 4.5% of 1.4bn people in the region is threatened, the researchers conclude.
More than 1.4bn people depend on water from the Indus, Ganges, Brahmaputra, Yangtze and Yellow rivers.
"We show that meltwater is extremely important in the Indus basin and important for the Brahmanputra basin, but only plays a modest role for the Ganges, Yangtze and Yellow rivers," the team from the Netherlands wrote.
"The Brahmaputra and Indus basins are most susceptible to reductions of flow, threatening the food security of an estimated 60m people."
The researchers described mountains as the "water towers of the world".
"Snow and glacial melt are important hydrological processes... and changes in temperature and precipitation are expected to seriously affect the melt characteristics," they explained.
Summer rains
The team used data to assess a number of factors to reach their conclusions, including: the current importance of meltwater in overall river basin hydrology; observed cyrospheric changes; and the effects of climate change on the water supply from the upstream basins and on food security.
"The Yellow River, in particular, shows a consistent increase in early spring discharge, " they said.
"This is highly beneficial because most reservoirs are empty at the beginning of the growing season.
"An accelerated melt peak may thus alleviate a shortage of irrigation water in the drought-prone early stages of the growing season."
However, despite the projected compensating effects of increased rainfall in the Indus and Brahmaputra basins, the team predicted that summer and late spring discharges would eventually be reduced "consistently and considerably by 2046 to 2065 after a period with increase flows as a result of accelerated glacial melt".
"These anticipated changes will also have considerable effects on food security," they warned.
"By relating changes in upstream water availability to net irrigation requirements, observed crop yields, calorific value of the crops and required human energy consumption, one can estimate the change in the number of people that can be fed."
The team estimates that about 34.5m fewer people could be fed in the Brahmaputra basin; 26.3m fewer in the Indus basin; 7.1m in the Yangtze region and about 2.1m fewer around the Ganges.
However, they suggested that the changes could see an increase in food production in the Yellow River basin, enough to feed a further 3m people.
"In total, we estimate that the food security of 4.5% of the total population will be threatened as a result of reduced water availability," they concluded.
"The strong need for prioritising adaptation options and further increasing water productivity is therefore ever more eminent.
"We conclude that Asia's water towers are threatened by climate change, but the effects of climate change on water availability and food security in Asia differ substantially among basins and cannot be generalised.
"The effects in the Indus and Brahmaputra basins are likely to be severe owing to the large population and the high dependence on irrigated land and meltwater.
"In the Yellow River, climate change may even yield a positive benefit as the dependence on meltwater is low and a projected increased upstream precipitation, when retained in reservoirs, would enhance water availability for irrigated agriculture and food security."
[bbc.co.uk > Science & Environment]
Page last updated at 09:46 GMT, Friday, 11 June 2010 10:46 UK
Japan unfurls solar sail in orbit
｛日本、軌道上で太陽光を受ける帆を展開｝
{An image of the deployment is sent back to Earth}
Japanese scientists are celebrating the successful deployment of their solar sail Ikaros.
｛日本の科学者、宇宙ヨット「イカロス」の帆の展開の成功を祝う｝
The 200-sq-m (2,100-sq-ft) membrane is attached to a small disc-shaped spacecraft that was put in orbit last month by an H-IIA rocket.
Ikaros will demonstrate the principle of using sunlight as a simple and efficient means of propulsion.
The technique has long been touted as a way of moving spacecraft around the Solar System using no chemical fuels.
The mission team will be watching to see if Ikaros produces a measurable acceleration, and how well its systems are able to steer the craft through space.
The Japan Aerospace Exploration Agency (Jaxa) said in a statement that its scientists and engineers had begun to deploy the solar sail on 3 June (JST). On 10 June, Jaxa said, confirmation was received that the sail had expanded successfully and was generating power through the thin film solar cells embedded in the membrane
The deployment occurred about seven million km from Earth.
Ikaros was a piggy-back payload to Japan's Venus orbiter Akatsuki. The pair were boosted in to space on 21 May (JST) from the Tanegashima Space Center.
Akatsuki will arrive at Venus in December. Key goals include finding definitive evidence for lightning and for active volcanoes.
{{SAILING TO VENUS - HOW IKAROS UNFURLS ITS SOLAR SAIL}
(1) For the deployment, the disc-shaped Ikaros spacecraft was first spun up
(2) The four weighted corners of the sail were then released and flew outwards
(3) Finally, the packed sail membrane was released and pulled flat by the rotating tips}
[bbc.co.uk > Science & Environment]
Page last updated at 08:16 GMT, Friday, 11 June 2010 09:16 UK
By Mark Kinver
Science and environment reporter, BBC News
Himalayan climate impacts 'cannot be generalised'
｛ヒマラヤの気候温暖化の影響は総括的に述べれない｝
{Mountain glaciers provide vital lifeblood for some of Asia's major rivers}
｛アジアの大河には、山の氷河が極めて重要な活力源になっているものがある｝
Melting glaciers in the Himalayas will have varying impacts on the region's five major river basins, a study says.
｛調査報告書によると、ヒマヤラの氷山の溶解が５大河川流域に種々の影響を及ぼしている｝
Changes to the flow of meltwater as a result of global warming is likely to have a "severe" impact on food security in some area, say scientists.
Yet people living elsewhere are likely to see food productivity increase, they added in a paper published in Science.
Overall, the food security of 4.5% of 1.4bn people in the region is threatened, the researchers conclude.
More than 1.4bn people depend on water from the Indus, Ganges, Brahmaputra, Yangtze and Yellow rivers.
"We show that meltwater is extremely important in the Indus basin and important for the Brahmanputra basin, but only plays a modest role for the Ganges, Yangtze and Yellow rivers," the team from the Netherlands wrote.
"The Brahmaputra and Indus basins are most susceptible to reductions of flow, threatening the food security of an estimated 60m people."
The researchers described mountains as the "water towers of the world".
"Snow and glacial melt are important hydrological processes... and changes in temperature and precipitation are expected to seriously affect the melt characteristics," they explained.
Summer rains
The team used data to assess a number of factors to reach their conclusions, including: the current importance of meltwater in overall river basin hydrology; observed cyrospheric changes; and the effects of climate change on the water supply from the upstream basins and on food security.
"The Yellow River, in particular, shows a consistent increase in early spring discharge, " they said.
"This is highly beneficial because most reservoirs are empty at the beginning of the growing season.
"An accelerated melt peak may thus alleviate a shortage of irrigation water in the drought-prone early stages of the growing season."
However, despite the projected compensating effects of increased rainfall in the Indus and Brahmaputra basins, the team predicted that summer and late spring discharges would eventually be reduced "consistently and considerably by 2046 to 2065 after a period with increase flows as a result of accelerated glacial melt".
"These anticipated changes will also have considerable effects on food security," they warned.
"By relating changes in upstream water availability to net irrigation requirements, observed crop yields, calorific value of the crops and required human energy consumption, one can estimate the change in the number of people that can be fed."
The team estimates that about 34.5m fewer people could be fed in the Brahmaputra basin; 26.3m fewer in the Indus basin; 7.1m in the Yangtze region and about 2.1m fewer around the Ganges.
However, they suggested that the changes could see an increase in food production in the Yellow River basin, enough to feed a further 3m people.
"In total, we estimate that the food security of 4.5% of the total population will be threatened as a result of reduced water availability," they concluded.
"The strong need for prioritising adaptation options and further increasing water productivity is therefore ever more eminent.
"We conclude that Asia's water towers are threatened by climate change, but the effects of climate change on water availability and food security in Asia differ substantially among basins and cannot be generalised.
"The effects in the Indus and Brahmaputra basins are likely to be severe owing to the large population and the high dependence on irrigated land and meltwater.
"In the Yellow River, climate change may even yield a positive benefit as the dependence on meltwater is low and a projected increased upstream precipitation, when retained in reservoirs, would enhance water availability for irrigated agriculture and food security."
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