Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Measuring ozone from space

19.09.2016

Today is the UN’s International Day for the Preservation of the Ozone Layer – the perfect opportunity to look at how and why measurements of this molecule are taken from space.

The hole in the ozone layer over Antarctica became an international cause for concern in the latter half of the 20th Century, but as EUMETSAT’s Atmospheric Composition Product Development Team Leader Dr Christian Retscher points out, issues relating to ozone levels are complex and wide-reaching.


Measurements from GOME-2, together with information from model runs, provide a forecast for 2 September of the total column amount of ozone over the South Pole. Compared to other regions on Earth, meteorological conditions there favour faster ozone depletion at this time of year and this is clear from the blue and dark blue coloured areas, which are considered low levels of ozone.


GOME-2 measures the total column amount of ozone through both the stratosphere and troposphere as it orbits the Earth, as shown in this image comprising a composite of measurements taken over one day. The blank area over the South Pole illustrates that lack of sunlight affects GOME-2’s ability to take measurements there at this time of year and why various other sources of data were needed to create the first image above. This image uses a different colour scale to indicate ozone thickness but the blue and dark blue areas again show thinner levels.

What is ozone?

Ozone is a molecule consisting of three oxygen atoms and occurs naturally in the atmosphere. However, close to the surface of the Earth, it is considered a pollutant.

The ozone layer in the stratosphere, with a bulk concentration at 15-30km above the surface of the Earth, is crucial for protecting humans and other species from the harmful effects of ultraviolet radiation from the sun, Christian said.

The ozone layer in the stratosphere absorbs UV radiation. While UV radiation is essential for life on Earth, it is also linked to skin cancer and damage to plant life. That is why the thinning of the ozone layer (often referred to as the ozone hole), causes concern.

But measurements of ozone in the troposphere (the lowest level of the Earth’s atmosphere, extending up to between 7km above sea level at polar regions and 20km over the tropics) are also needed because this molecule, which can be a by-product of industrial production, is harmful to breathe and damaging to plants.

About 90 per cent of ozone is in the stratosphere and 10 per cent in the troposphere, Christian said.

Measuring and monitoring ozone

EUMETSAT’s Metop-A (launched in 2006) and Metop-B (2012) satellites, flying in a sun-synchronised polar orbit approximately 817km above the Earth’s surface, carry an instrument called GOME-2 (Global Ozone Monitoring Experiment), which is dedicated to measuring ozone in the atmosphere.

“GOME-2 maps ozone from above,” Christian explains. “It takes total column (through the stratosphere and troposphere) ozone measurements.

“What is important about GOME-2 is that this is an instrument of an operational satellite mission, in other words, we are flying the same sensor more than once. This provides long time series of measurements, contributes to a better understanding of ozone production and destruction processes and also allows trend analysis.

“The primary goal is to measure how the ozone layer is changing in general, not only the so-called ozone hole over Antarctica. There, meteorological conditions favour the accelerated depletion of stratospheric ozone, but ozone is thinning over the Arctic as well.

“When we look at how the ozone is behaving over the long term, what we hope to see is that stratospheric ozone is recovering somewhat.

“Specifically, measurements from the last couple of years hint at a slight recovery of the stratospheric ozone layer over the South Pole.”

Ozone in the troposphere

“When we look at ozone with instruments like GOME-2, we see the whole column, but we want to separate between the troposphere and stratosphere,” Christian added.

“While ozone measurements in the stratosphere are more related to climate aspects, thus long-term effects, ozone in the troposphere has different implications for human health.

“When we are measuring ozone in the troposphere, short term trends or diurnal variations of ozone concentrations are much more relevant. We are interested in improvements over short time ranges like hours or days and much finer geographical scales, for example, cities.

“When inhaled, ozone is harmful to the respiratory system, so what is interesting is the understanding of changes of ozone levels on, for example, a daily basis. How much ozone is there and what is the threat level - is it safe for you to be outside or not? Novel instruments, for example, Sentinel-4, will support this kind of research since ozone profile data will be available on an hourly basis.”

Instruments measuring ozone

The GOME-2 instruments are dedicated to monitoring ozone but are not the only satellite-borne instruments taking ozone measurements.

Metop satellites also carry the Infrared Atmospheric Sounding Interferometer (IASI) instruments, which measure ozone as well.

Other relevant European ozone-monitoring instruments were GOME on ERS-2 , or SCIAMACHY, MIPAS and GOMOS, which were flown on ESA’s Envisat satellite. Very important contributions to ozone research are based on the more than 30 years time series of data from satellites flown by, for example, NASA and NOAA, with the successful series of TOMS , SBUV , POAM , and SAGE instruments or the later OMI or the OMPS sensors.

Planning is well in hand to continue monitoring ozone into the future.

Metop-A is approaching the end of its lifetime in space but Metop-C, also with a GOME-2 instrument, is expected to be launched in 2018, so the all-important long time series of measurements will be maintained.

Under the EU’s flagship Copernicus programme for monitoring the environment from space, EUMETSAT’s Meteosat Third Generation (MTG) geostationary meteorological satellites, and the EPS-Second Generation satellites will carry the Copernicus Sentinel-4 and -5 instruments respectively. Prior to these, ESA will launch the Sentinel-5 Precursor mission. All of these Sentinels have capacity to monitor ozone. In addition, there will be other European sensors in space supporting the monitoring of ozone, although not their primary mission objective, for example, IASI-NG (IASI- Next Generation) on EPS-SG and the IRS (Infrared Sounder) on MTG-S.

EUMETSAT will launch its EPS-SG satellites in the 2022-2042 timeframe, while the first in the series of MTG-S (sounding) platforms is expected to be launched in 2022 as well.

About today

In 1994, the United Nationals General Assembly declared 16 September the International Day for Preservation of the Ozone Layer to commemorate the day in 1987 when the Montreal Protocol was signed. This protocol phased-out the use of substances which deplete the ozone layer. (Resolution 49/114).

Note: acronyms used in the "Instruments measuring ozone section" are spelt out below.

·         SCIAMACHY - Scanning Imaging Absorption Spectrometer for Atmospheric Chartography

·         MIPAS - Michelson Interferometer for Passive Atmospheric Sounding

·         GOMOS- Global Ozone Monitoring by Occultation of Stars

·         TOMS – Total Ozone Mapping Spectrometer

·         SBUV – Solar Backscatter Ultraviolet Instrument

·         POAM – Polar Ozone and Aerosol Measurement

·         SAGE – Stratospheric Aerosol and Gas Experiment

·         OMI – Ozone Monitoring Instrument

·         OMPS – Ozone Mapping Profiler Suite

http://www.eumetsat.int/website/home/News/DAT_3203686.html?lang=EN&pState=1

Neil Fletcher | AlphaGalileo

More articles from Physics and Astronomy:

nachricht Climate cycles may explain how running water carved Mars' surface features
02.12.2016 | Penn State

nachricht What do Netflix, Google and planetary systems have in common?
02.12.2016 | University of Toronto

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>