NASA satellite that revealed ozone holes completes a decade in space

Aura has been sending data which has been invaluable in improving our understanding of pollutants

 
By Aditya Misra
Last Updated: Saturday 04 July 2015

image

NASA’s Aura satellite, which completed 10 years in space this week, has been providing data that has helped improve our understanding of environment pollutants, says the space agency.

The satellite was launched to observe atmospheric levels of ozone, aerosols, smoke, dust, clouds and greenhouse gases such as methane, carbon dioxide and water vapour. In 2006 and 2011, it revealed the presence of two of the largest and deepest holes in the ozone layer over the Antarctica, says the NASA website.

Ozone is a gas which is both necessary and harmful for our survival. In the stratosphere, it protects the Earth from Sun’s harmful ultraviolet rays. But if inhaled, it burns the lungs. It also damages plants.

Data collected between 2005 and 2010 showed a decline of four per cent in nitrogen dioxide levels in the US. Global levels of the gas increased over half per cent in the same period, according to NASA. In China, the increase in nitrogen dioxide levels every year was six per cent. Nitrogen dioxide causes respiratory problem and leads to formation of ozone.

The satellite also found presence of large amounts of sulphur dioxide around volcanoes and coal-burning power plants. The gas is known to cause formation of clouds which bring acid rains.

The satellite has four instruments:

  1. Tropospheric Emission Spectrometer (TES) to measure ammonia released from animal waste, fertilisers and soil;
  2. Microwave Limb Sounder (MLS)to measure cloud ice content in the upper troposphere
  3. Ozone Monitoring Instrument (OMI) to monitor levels of nitrogen dioxide, sulfur dioxide
  4. High Resolution Dynamics Limb Sounder (HIRDLS) instrument provided global maps showing cirrus clouds in the upper altitudes in the tropics.

Subscribe to Weekly Newsletter :
Related Stories

Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.