[:ja]No.114に続き、砂に関するトピックです。NASAの地球観測衛星Terraが2015年2月末に撮影した、西アフリカのセネガル、ガンビアから大西洋に向かって舞う黄砂です。季節風により、サハラ砂漠の砂が西方に流されています。
日本では、春に黄砂が中国大陸から飛来し、視界が悪くなったり車が汚れたり迷惑極まりないと思われがちですが、人工衛星から俯瞰してみると、黄砂の意外な事実が浮かび上がります。
このアフリカ西岸の黄砂は5千kmもの距離を旅し、なんと大西洋の対岸のアマゾンの熱帯雨林にまで到達するのです（5千kmというと東京－インド・コルカタの距離）。
NASAの研究では、この黄砂には植物の成長に不可欠なリンが豊富に含まれており、洪水や自然風化などで傷んだアマゾン地域の土壌に養分を供給している、つまり、生物の宝庫であるアマゾンの熱帯雨林の成長が少なからずアフリカ大陸の砂によって育まれている可能性もあると指摘します。
一歩引いた視点で、巨視的に、俯瞰的に物事を見てみると、局所的には人間にとって一見迷惑な自然の営みも、大きなスケールでは重要な意味を持つことがわかるかもしれません。
ちなみに、セネガルの地上の砂嵐の様子はこちら。
参考文献： Thick Dust Plumes Obscure Africa’s Coast
ウェブ地球儀で地球俯瞰画像を見る： LiVEARTH
[Earthview Wonders] No.115: Dust from Africa
Continued from No.114, this is another photo captured in February 2015 by NASA’s Terra of the Sahara Desert’s dust drifting from African continent to the Atlantic Ocean from Senegal and Gambia by seasonal Monsoon.
“Yellow Dust”, the dust plumes flown to Japan from Eurasia Continent in spring causing haze and pollution is received unplesantly, but overviewing from satellites reveals another surprising fact about this climatic event.
Dust from west coast of Africa travels 5,000km over the Atlantic Ocean to reach the Amazon rainforests of South America (5,000km is the approximate distance from New York, U.S. to Dublin, Ireland).
According to NASA, the Saharan dusts contain rock minerals such as phosphorous, an essential nutrient for plant proteins and growth, and is thought to provide nutrients for Amazon soils. Scientists point out the possibility of relationship between the growth of the vast Amazon rainforests and the Saharan sands.
Looking at things from one step back on a larger scale may give a valuable, new finding about the nature which may seem troublesome to humans on a smaller scale.
Dust storm in Senegal on the ground looks like this.
Reference: Thick Dust Plumes Obscure Africa’s Coast
See earthview photo gallery with web-globe: LiVEARTH[:en][Earthview Wonders] No.115: Dust from Africa
Continued from No.114, this is another photo captured in February 2015 by NASA’s Terra of the Sahara Desert’s dust drifting from African continent to the Atlantic Ocean from Senegal and Gambia by seasonal Monsoon.
“Yellow Dust”, the dust plumes flown to Japan from Eurasia Continent in spring causing haze and pollution is received unplesantly, but overviewing from satellites reveals another surprising fact about this climatic event.
Dust from west coast of Africa travels 5,000km over the Atlantic Ocean to reach the Amazon rainforests of South America (5,000km is the approximate distance from New York, U.S. to Dublin, Ireland).
According to NASA, the Saharan dusts contain rock minerals such as phosphorous, an essential nutrient for plant proteins and growth, and is thought to provide nutrients for Amazon soils. Scientists point out the possibility of relationship between the growth of the vast Amazon rainforests and the Saharan sands.
Looking at things from one step back on a larger scale may give a valuable, new finding about the nature which may seem troublesome to humans on a smaller scale.
Dust storm in Senegal on the ground looks like this.
Reference: Thick Dust Plumes Obscure Africa’s Coast
See earthview photo gallery with web-globe: LiVEARTH[:]