Trees in the Amazon make their own rain

first_img Country * Afghanistan Aland Islands Albania Algeria Andorra Angola Anguilla Antarctica Antigua and Barbuda Argentina Armenia Aruba Australia Austria Azerbaijan Bahamas Bahrain Bangladesh Barbados Belarus Belgium Belize Benin Bermuda Bhutan Bolivia, Plurinational State of Bonaire, Sint Eustatius and Saba Bosnia and Herzegovina Botswana Bouvet Island Brazil British Indian Ocean Territory Brunei Darussalam Bulgaria Burkina Faso Burundi Cambodia Cameroon Canada Cape Verde Cayman Islands Central African Republic Chad Chile China Christmas Island Cocos (Keeling) Islands Colombia Comoros Congo Congo, the Democratic Republic of the Cook Islands Costa Rica Cote d’Ivoire Croatia Cuba Curaçao Cyprus Czech Republic Denmark Djibouti Dominica Dominican Republic Ecuador Egypt El Salvador Equatorial Guinea Eritrea Estonia Ethiopia Falkland Islands (Malvinas) Faroe Islands Fiji Finland France French Guiana French Polynesia French Southern Territories Gabon Gambia Georgia Germany Ghana Gibraltar Greece Greenland Grenada Guadeloupe Guatemala Guernsey Guinea Guinea-Bissau Guyana Haiti Heard Island and McDonald Islands Holy See (Vatican City State) Honduras Hungary Iceland India Indonesia Iran, Islamic Republic of Iraq Ireland Isle of Man Israel Italy Jamaica Japan Jersey Jordan Kazakhstan Kenya Kiribati Korea, Democratic People’s Republic of Korea, Republic of Kuwait Kyrgyzstan Lao People’s Democratic Republic Latvia Lebanon Lesotho Liberia Libyan Arab Jamahiriya Liechtenstein Lithuania Luxembourg Macao Macedonia, the former Yugoslav Republic of Madagascar Malawi Malaysia Maldives Mali Malta Martinique Mauritania Mauritius Mayotte Mexico Moldova, Republic of Monaco Mongolia Montenegro Montserrat Morocco Mozambique Myanmar Namibia Nauru Nepal Netherlands New Caledonia New Zealand Nicaragua Niger Nigeria Niue Norfolk Island Norway Oman Pakistan Palestine Panama Papua New Guinea Paraguay Peru Philippines Pitcairn Poland Portugal Qatar Reunion Romania Russian Federation Rwanda Saint Barthélemy Saint Helena, Ascension and Tristan da Cunha Saint Kitts and Nevis Saint Lucia Saint Martin (French part) Saint Pierre and Miquelon Saint Vincent and the Grenadines Samoa San Marino Sao Tome and Principe Saudi Arabia Senegal Serbia Seychelles Sierra Leone Singapore Sint Maarten (Dutch part) Slovakia Slovenia Solomon Islands Somalia South Africa South Georgia and the South Sandwich Islands South Sudan Spain Sri Lanka Sudan Suriname Svalbard and Jan Mayen Swaziland Sweden Switzerland Syrian Arab Republic Taiwan Tajikistan Tanzania, United Republic of Thailand Timor-Leste Togo Tokelau Tonga Trinidad and Tobago Tunisia Turkey Turkmenistan Turks and Caicos Islands Tuvalu Uganda Ukraine United Arab Emirates United Kingdom United States Uruguay Uzbekistan Vanuatu Venezuela, Bolivarian Republic of Vietnam Virgin Islands, British Wallis and Futuna Western Sahara Yemen Zambia Zimbabwe Antisana/Alamy Stock Photo Fu thought it was possible that plants were releasing enough moisture to build low-level clouds over the Amazon. But she needed to explicitly connect the moisture to the tropical forest.So Fu and her colleagues observed water vapor over the Amazon with NASA’s Aura satellite, a spacecraft dedicated to studying the chemistry of Earth’s atmosphere. Moisture that evaporates from the ocean tends to be lighter than water vapor released into the atmosphere by plants. That’s because during evaporation, water molecules containing deuterium, a heavy isotope of hydrogen made of one proton and one neutron, get left behind in the ocean. By contrast, in transpiration, plants simply suck water out of the soil and push it into the air without changing its isotopic composition.Aura found that the early moisture accumulating over the rainforest was high in deuterium—“too high to be explained by water vapor from the ocean,” Fu says. What’s more, the deuterium content was highest at the end of the Amazon’s dry season, during the “greening” period when photosynthesis was strongest.The tree-induced rain clouds could have other domino effects on the weather. As those clouds release rain, they warm the atmosphere, causing air to rise and triggering circulation. Fu and colleagues believe that this circulation is large enough that it triggers the shift in wind patterns that will bring in more moisture from the ocean, they report in the Proceedings of the National Academy of Sciences.Scientists have studied the connection between trees and rain in the Amazon before. A 2012 study found that plants help “seed” the atmosphere for rain by releasing tiny salt particles. But the new study strongly supports the idea that plants play an important role in triggering the rainy season, says Scott Saleska, an ecologist at the University of Arizona in Tucson, who was not involved with the work. The deuterium provides a clear “fingerprint” for what plants contribute to the process, he says.The findings also address a long-standing debate about the role plants play in weather, says Saleska, suggesting that they are more than just “passive recipients,” and that they instead can play an active role in regulating rainfall. If that’s true in the Amazon, Saleska says, climate scientists will need to take into account practices like deforestation when predicting regional changes in weather patterns. And curbing deforestation will be an important step for people to take in preventing drought.Next, Fu will be studying rainforests in the Congo, to see whether the same process is happening. By Ilima LoomisAug. 4, 2017 , 2:45 PM The Amazon rainforest is home to strange weather. One peculiarity is that rains begin 2 to 3 months before seasonal winds start to bring in moist air from the ocean. Now, researchers say they have finally figured out where this early moisture comes from: the trees themselves.The study provides concrete data for something scientists had theorized for a long time, says Michael Keller, a forest ecologist and research scientist for the U.S. Forest Service based in Pasadena, California, who was not involved with the work. The evidence the team provides, he says, is “the smoking gun.”Previous research showed early accumulation of moisture in the atmosphere over the Amazon, but scientists weren’t sure why. “All you can see is the water vapor, but you don’t know where it comes from,” says Rong Fu, a climate scientist at the University of California, Los Angeles. Satellite data showed that the increase coincided with a “greening” of the rainforest, or an increase in fresh leaves, leading researchers to suspect the moisture might be water vapor released during photosynthesis. In a process called transpiration, plants release water vapor from small pores on the underside of their leaves. Sign up for our daily newsletter Get more great content like this delivered right to you! Countrycenter_img Email Trees in the Amazon make their own rain Click to view the privacy policy. Required fields are indicated by an asterisk (*) Clouds over the Amazon.last_img read more