The second layer of Earth’s atmosphere is stratospheric layer. In the layer airplanes travel with good stability where the air currents in this layer are Low. The air in the layer is dry and clear, and much calmer. The stratosphere pulling air up from the Earth’s equatorial region and pushing it back down toward the poles in circulating pattern. The circulation can impact the amount of water vapor, chemicals, and ozone around the planet.
Scientists from MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS) on observations of key chemicals traveling within this atmospheric layer. They determined the strength of the stratosphere’s circulation. Stratosphere pulls about 7 billion kilograms of air up per second worldwide, at an altitude of 20 kilometers. The researchers estimate that the average amount of air can spend about 1.5 years in this layer. Before circulating back down to lower layers of the atmosphere.
Scientists to determine future changes in the stratosphere’s strength essential information for tracking the recovery of the ozone hole and the progression of global warming.
Sulfur hexafluoride and Nitrous oxide Chemicals Used to track
The circulation of the stratosphere is known to scientists as the southern overturning pattern. Scientists have attempted to measure the strength of this overturning circulation, concentrating mainly on the speed at which water vapor rises through the stratosphere near the equator. They considered these sulfur hexafluoride and nitrous oxide chemicals to track. Although there are no methods by which the concentration of these gases would change once they reached the stratosphere.
The scientists compiled measurements of both chemicals between 2007 and 2011. The idea of estimating these chemicals to enter, then exit, the stratosphere. They obtain through the measurements, noting each chemical’s concentrations. The given parcels of air throughout the stratosphere at various locations and altitudes.
In particular, they looked over time to identify parcels of air rising up in the tropics. Meanwhile, parcels of air with the same concentration of chemicals, being drawn back down at the poles.
Circulation strength 7 billion kilograms per second
They reasoned that the time lag between the rising and sinking would indicate the time that parcel spent in the stratosphere. Moreover, simple calculation, factoring in the total mass of air in the stratosphere, would yield the speed at which that parcel traveled through the stratosphere, which essentially reflects the strength of circulation.
The team performed these calculations and averaged the results for various altitudes throughout the stratosphere. Their calculations for both chemicals agreed almost perfectly at lower altitudes of around 20 kilometers. About a circulation strength of about 7 billion kilograms per second. Comparable in magnitude to the strength of the overturning circulation in the ocean.
However, Predictions of stratospheric circulation made by several climate models, and found that their estimate agreed with some models. Furthermore methods to calculate the stratosphere’s strength, can help to improve model predictions of warming and ozone development.
Although, the researchers are working to obtain more measurements Higher in the stratosphere. To better characterize the stratosphere’s strength at higher altitudes as well as within lower layers.