2/17/2024 0 Comments Nasa pc amazonNormally always wet, the northwest has suffered severe droughts over the past two decades, a further indication of the entire forest’s vulnerability to increasing temperatures and dry air. But they also found episodic drying in the northwest Amazon, an area that typically has no dry season. Scientists observed that the most significant and systematic drying of the atmosphere is in the southeast region, where the bulk of deforestation and agricultural expansion is happening. “Our study shows that the demand is increasing, the supply is decreasing and if this continues, the forest may no longer be able to sustain itself.” But the soil doesn’t have extra water for the trees to pull in,” said JPL’s Sassan Saatchi, co-author of the study. With the increase in temperature and drying of the air above the trees, the trees need to transpire to cool themselves and to add more water vapor into the atmosphere. Rainforests generate as much as 80% of their own rain, especially during the dry season.īut when this cycle is disrupted by an increase in dry air, for instance, a new cycle is set into motion - one with significant implications, particularly in the southeastern Amazon, where trees can experience more than four to five months of dry season. The clouds produce rain that replenishes the water in the soil, allowing the cycle to continue. They pull in water from the soil through their roots and release water vapor through pores on their leaves into the atmosphere, where it cools the air and eventually rises to form clouds. Trees and plants need water for photosynthesis and to cool themselves down when they get too warm. ![]() By removing CO2 from the atmosphere, the Amazon helps to keep temperatures down and regulate climate.īut it’s a delicate system that’s highly sensitive to drying and warming trends. When healthy, it absorbs billions of tons of carbon dioxide (CO2) a year through photosynthesis - the process plants use to convert CO2, energy and water into food. The Amazon is the largest rainforest on Earth. When the black carbon absorbs heat from the sun, it causes the atmosphere to warm it can also interfere with cloud formation and, consequently, rainfall. While bright-colored or translucent aerosols reflect radiation, darker aerosols absorb it. When a forest burns, it releases particles called aerosols into the atmosphere - among them, black carbon, commonly referred to as soot. The combination of these activities is causing the Amazon’s climate to warm. The rest is the result of ongoing human activity, most significantly, the burning of forests to clear land for agriculture and grazing. So if it’s not natural, what’s causing it?īarkhordarian said that elevated greenhouse gas levels are responsible for approximately half of the increased aridity. ![]() “In comparing this trend to data from models that estimate climate variability over thousands of years, we determined that the change in atmospheric aridity is well beyond what would be expected from natural climate variability.”Ĭredit: NASA/JPL-Caltech, NASA Earth Observatory “We observed that in the last two decades, there has been a significant increase in dryness in the atmosphere as well as in the atmospheric demand for water above the rainforest,” said JPL’s Armineh Barkhordarian, lead author of the study. Scientists at NASA’s Jet Propulsion Laboratory in Pasadena, California, analyzed decades of ground and satellite data over the Amazon rainforest to track both how much moisture was in the atmosphere and how much moisture was needed to maintain the rainforest system. It also shows that this increase in dryness is primarily the result of human activities. ![]() Credit: Marcio Isensee e Sa / Adobe StockĪ new NASA study shows that over the last 20 years, the atmosphere above the Amazon rainforest has been drying out, increasing the demand for water and leaving ecosystems vulnerable to fires and drought.
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