• → European Space Agency

      • Space for Europe
      • Space News
      • Space in Images
      • Space in Videos
    • About Us

      • Welcome to ESA
      • DG's news and views
      • For Member State Delegations
      • Business with ESA
      • Law at ESA
      • ESA Exhibitions
      • ESA Publications
      • Careers at ESA
      • ESAshop
    • Our Activities

      • Space News
      • Observing the Earth
      • Human Spaceflight
      • Space Transportation
      • Navigation
      • Space Science
      • Space Engineering & Technology
      • Operations
      • Telecommunications & Integrated Applications
      • Preparing for the Future
    • Careers at ESA

    • For Media

      • Media
      • ESA TV
      • Videos for professionals
      • Photos
    • For Educators

    • For Kids

    • ESA

    • Observing the Earth

    • Space for our climate

    • About climate change
    • Space in climate change
    • Space and Earth Monitoring

      • Land

        • Overview
        • Rivers & lakes
        • Volcanoes
        • Coastal zones
        • Wetlands & deserts
      • Oceans

        • Overview
        • Wind & waves
        • Ocean colour & algae blooms
        • Sea Surface Temperature
        • El Niño
      • Ice

        • Overview
        • Ice and climate
      • Atmosphere

        • Overview
        • Water vapour & clouds
        • Aerosols
        • Ozone hole
        • Climate change
      • Biosphere

        • Overview
        • Forests
        • Carbon cycle
    • ESA's Climate Change Initiative (CCI)

      • A global challenge
      • A European response
      • Counting carbon
      • An ocean of change
      • Ice retreat
      • Mapping methane
      • Talking climate
    • International treaties implementation

      • Overview
      • Wetlands convention
      • Combat Desertification convention
      • Kyoto Protocol
    • About Earth observation

      • View from above
      • ESA for Earth
      • How to access data
    • Multimedia
    • Image Gallery
    • Video Gallery

    ESA > Our Activities > Observing the Earth > Space for our climate

    Loading...
    Monitoring ozone
    Access the video

    Ozone ups and downs

    15 November 2017

    Climate scientists studying three decades of ozone measurements from seven satellites see a positive trend in global recovery thanks to international efforts to curb ozone-depleting substances.

    The part of Earth’s atmosphere with high concentrations of ozone gas protects life on Earth from the Sun’s ultraviolet radiation. However, pollutants can break down ozone, thinning this ozone layer and creating the infamous ozone hole.

    The depletion of ozone in our atmosphere and subsequent increase in ultraviolet exposure causes skin cancer, cataracts and immune system damage in humans, and injures animals, plants and even microscopic phytoplankton.

    Starting in the 1970s, ozone in the stratosphere – some 11–50 km above Earth’s surface – began to decline worldwide. The largest drop was in the upper stratosphere, at 4–8% per decade.

    The trend was interrupted following international agreements on the reduction of ozone-depleting substances and the first signs of ozone recovery were seen by satellites.

    Satellites provide good coverage but operate for a limited number of years. Meanwhile, climate scientists require readings spanning 30 years or more for analysing trends accurately.

    Ozone in particular varies depending on the season or solar activity, so decades are necessary to separate this natural variability from human-influenced change.

    To tackle this, scientists working under ESA’s Climate Change Initiative are harmonising measurements from different satellites to give us a long-term view of ozone variability.

    Shift in ozone trends

    The readings date back to 1995 for ‘total columns’ – meaning they show the total ozone of all layers of the atmosphere – and to 2001 for ozone profiles with high vertical resolution, meaning the separate layers can be identified.

    The record relies on five satellite sensors that provide measurements with high vertical resolution. These include the ones on ESA’s former Envisat mission, along with current information from Canada’s SciSat and Sweden’s Odin.

    In a new development, measurements from NASA’s Earth Radiation Budget Satellite and Suomi NPP satellite have been folded in, further extending coverage back to 1984.

    “By merging the Climate Change Initiative’s data with NASA’s, we clearly see negative ozone trends in the upper atmosphere before 1997 and positive trends after,” concludes Viktoria Sofieva, Senior Research Scientist at the Finnish Meteorological Institute.

    “The upper stratospheric trends beyond the tropics are statistically significant and indicate an onset of ozone recovery.”

    Ozone measurements with high vertical resolution are essential to identify these ozone trends. The future Altius mission for ESA’s Earth Watch initiative will provide continuing measurements for long-term climate monitoring.

    Rate this

    Views

    Share

    • Currently 5 out of 5 Stars.
    • 1
    • 2
    • 3
    • 4
    • 5
    Rating: 4.8/5 (104 votes cast)

    Thank you for rating!

    You have already rated this page, you can only rate it once!

    Your rating has been changed, thanks for rating!

    5175
    Tweet
    • Published paper
    • Merged SAGE II, Ozone_cci and OMPS ozone profile dataset and evaluation of ozone trends in the stratosphere
    • Related links
    • Ozone CCI
    • Finnish Meteorological Institute
    • Related missions
    • Envisat
    • SciSat
    • Odin
    • S-NPP/OMPS
    • SAGE II
    • App Store
    • Subscribe
    • mobile version
    • ESA Observing the Earth Twitter

    @ESA_EO

    • LATEST ARTICLES
    • · Walking on the Moon – underwater
    • · Storm hunter in position
    • · Mars impact crater or supervolcano?
    • · Top tomatoes thanks to Mars missio…
    • · Mars Express v2.0
    • FAQ

    • Site Map

    • Contacts

    • Terms and conditions