The European Brewer Network

The COST Action ES1207 coordinates Brewer spectrophotometer measurements of total ozone column, spectral UV irradiance and aerosol optical depth (AOD) in the UV range within Europe. The main objective of this initiative is to unite the ozone, UV and AOD European communities through a formally network (EUBREWNET) capable of delivering a consistent, spatially homogeneous European data resource.

A Brewer ozone spectrophotometer open congress will take place in Tenerife 24-28 of March 2014. This event is a joint collaboration of EUBREWNET and WMO-GAW Brewer Users Group and will focus on operational, scientific and technical issues of the Brewer instrument.

More information at:

http://www.eubrewnet.org/cost1207/

Some new questions about the ozone layer

A recent paper published in Green and Sustainable Chemistry by Dr. González-Velasco explains the depletion-recovery cycle of the ozone layer on the basis of the paramagnetic or diamagnetic of oxygen, ozone, nitrogen oxides and chlorine combinations. Thus, the effects of the Earth’s magnetic field on gaseous fluxes polar and equatorial-wards could give a novel explanation of the seasonal, latitude and altitude variations in the ozone concentration. Furthermore, changes in the magnetic field strength could also have an influence on the equilibriums of chemical or photochemical reactions participating in those mechanisms related to ozone layer.

The author states that in order to verify that such a magnetic effect is actually playing a role it could be interesting to try to correlate eventual changes in the magnetic field strength produced during the year at different latitudes with variations in the rates of the depletion-recovery cycle of the ozone.

Atmospheric Science Events in 2012

During the next year 2012, there will take place several interesting conferences related to the Atmospheric Sciences:

- International Radiation Symposium, 6-10 August, Berlin, Germany

- Quadrennial Ozone Symposium, 27-31 August, Toronto, Canada

- European Aerosol Conference, 2-7 September, Granada, Spain

- Atmospheric Science Conference, 18-22 June, Bruges, Belgium

- EUMETSAT Meteorological Satellite Conference, 3-7 September, Sopot, Poland

- EGU General Assembly, 22-27 April, Vienna, Austria

- SPIE Remote Sensing, 24-27 September, Edinburgh, United Kingdom.

- IEEE Geoscience and Remote Sensing Symposium, 22-27 July, Munich, Germany

- International Conference on Clouds and Precipitation, July 30 - August 03, Leipzyg, Germany

- European Meeting on Atmospheric Studies by Optical Methods, 20-24 August, Sopot, Poland

- International Conference on Meteorology, Climatology and Atmospheric Physics, May 30 - 1 June, Athens, Grecee

Atmospheric Composition Portal

The Atmospheric Composition Portal (ACP) aims to provide a community-oriented framework that applies best practices in information science and technology to atmospheric composition science. This portal is being developed by the Atmospheric Composition Constellation (ACC) and the Workgroup for Information Systems and Services (WGISS) within the Committee on Earth Observation Satellites (CEOS).

Effects of an asteroid strike into ocean on the ozone layer

A very interesting paper “Ozone perturbation from medium-size asteroid impacts in the ocean” by Pierazzo et al. has been published in Earth and Planetary Science Letters. These authors have shown by simulations that if an asteroid 500 m to 1 km in diameter were to hit the Pacific Ocean it would eject enough water vapor and sea salt into the atmosphere to affect the ozone layer.

The simulations showed that mid-latitude oceanic impacts of 1 km asteroids could produce a significant, global perturbation of upper atmospheric chemistry, including multi-year global ozone depletion comparable to ozone hole records registered in the mid-1990s. In addition, this ozone depletion would produce ultraviolet index (UVI) levels higher than 20 at the Earth’s surface during about two years in both the northern and southern hemispheres.

ACTRIS Project

ACTRIS (Aerosols, Clouds, and Trace gases Research InfraStructure Network) is a European Project aiming at integrating European ground-based stations equipped with advanced atmospheric probing instrumentation for aerosols, clouds, and short-lived gas-phase species. This European ground-based network will contribute to:

- providing long-term observational data relevant to climate and air quality research produced with standardized or comparable procedures;

- supporting transnational access to large infrastructures strengthening collaboration in and outside the EU and access to high quality information and services to the user communities;

- developing new integration tools to fully exploit the use of atmospheric techniques at ground-based stations, in particular for the calibration/validation/integration of satellite sensors and for the improvement of global and regional-scale climate and air quality models.

New version of TOGOMI/TOSOMI retrieval algorithms

The two European satellite-borne atmospheric sensors Global Ozone Monitoring Experiment (GOME) and the SCanning Imaging Absorption spectrometer for Atmospheric CHartographY (SCIAMACHY) are currently operational and offer the potential for an assessment of the global total ozone distribution covering an expected time span of over 18 years.

The Royal Netherlands Meteorological Institute (KNMI) has developed two retrieval algorithms to derive the total ozone data from these two European satellite instruments. These two retrieval algorithms are the Total Ozone retrieval scheme for the GOME instrument based on the OMI DOAS algorithm (TOGOMI), and the corresponding application to the SCIAMACHY instrument (TOSOMI).

A new version (2.0) of these two retrieval algorithms has been prepared by KNMI staff, and the new total ozone data are distributed via internet from the Tropospheric Emission Monitoring Internet Service (TEMIS)

Ozone depletion and climate change: impacts on UV radiation

A really interesting paper has been recently published by McKenzie et al. in Photochem. Photobiol. Sci.. This article presents a well documented review of the relationship between ozone depletion and climate change and its influence on the UV radiation at Earth’s surface. The paper indicates that because of the success of the Montreal Protocol, increases in UV-B radiation during the last two decades have been small outside regions affected by the Antarctic ozone hole. In addition, other atmospheric factors (mainly clouds and aerosols) also play an outstanding role on the variability of UV radiation at surface. Thus, the influence of the ozone depletion (and its recovery) on the UV radiation has been difficult to detect at mid-latitudes. The authors state that “without the Montreal Protocol, peak values of sunburning UV radiation could have been tripled by 2065 at mid-northern latitudes.”.

Regarding the interactions between ozone and climate change, the paper analyses both the effects of the implementation of the Montreal Protocol on climate change, and the influence of the increasing greenhouse gases on ozone recovery.

Sixth Regional Brewer Calibration Center for Europe intercomparison

The 6th Regional Brewer Calibration Center for Europe (RBCC-E) intercomparison will be held at El Arenosillo Atmospheric Sounding Station of the "Instituto de Técnica Aeroespacial" (INTA) during the period July 5 to 15 2011. This will be a join execercise of the Dobson and Brewer calibration centers for Europe. The QASUME unit of the Physikalisch-Meteorologisches Observatorium Davos / World Radiation Center (PMOD /WRC) will participate and provide a global UV reference spectrum for the ultraviolet measurements.
The campaign is scheduled in three main phases:
* Initial calibration to assess the current calibration of the instruments.
* Servicing, adjustments and maintenance works characterization test of the instruments.
* Final calibration. In this phase the ‘UV’ calibrations against the QASUME
Specific measurements for Brewer/Dobson comparison

Detailed information is available at the RBCC-E web page.

Ozone_cci project

The Ozone_cci project is part of the ESA Climate Change Initiative (CCI) Programme. Ozone_cci will develop, produce and validate long-term series of high quality global observations of atmospheric ozone derived from multiple satellite instruments that are essential to assess the fate of atmospheric ozone.
The task of the ESA Ozone-cci project is to improve on the scientific and operational exploitation of current European and Third Party Mission ozone monitoring sensors, by creating merged multi-sensors Essential Climate Variable (ECV) ozone time series that match the requirements formulated by GCOS, and allow reducing current uncertainties on the determination of ozone trends.
The Ozone_cci project team consists of 13 European partner institutions which are experts in the area of satellite retrieval algorithms, geophysical validation, system engineering and chemistry-climate modelling.

Scientific Assessment of Ozone Depletion 2010

The WMO/UNEP “Scientific Assessment of Ozone Depletion: 2010” will be ready in early 2011, but the executive summary of this report is already available. It provides new information about the relationship between the ozone layer and climate change, and highlights the successful implementation of the Montreal Protocol and its amendments.
The summary states that over the past decade, global ozone is no longer decreasing but is not yet increasing. Using numerical models of the Earth’s atmosphere, the report predicts that the stratospheric ozone layer will fully recover within the next 50 years.
Regarding the influence of ozone changes on ultraviolet radiation, the executive summary says that large UV levels in Antarctica continue to be seen when the springtime ozone hole is large. For instance, the Antarctic spring erythemal irradiance is approximately twice that measured in the Arctic for the same season. In addition, it is reaffirmed that at mid-latitudes, surface UV radiation has been about constant over the last decade, consistent with total ozone column observations over this period.

The empirically corrected TOMS data

In July 1996, the Total Ozone Mapping Spectrometer (TOMS) instrument was launched on the Earth Probe (EP) satellite. The total ozone column (TOC) observations derived from this satellite instrument began to display significant deviations from the ground truth by the middle of the year 2000. Haffner et al. (2004) indicated that the detected error in the instrument performance appears to depend on latitude, season, lifetime, and wavelength Thus, NASA GSFC warned users that EP-TOMS TOC data after the year 2000 are not recommended for the calculation of long-term ozone trends. To correct the influence of this instrument degradation, an empirical calibration technique was applied to the TOC data according to the personal comunication of McPeters et al. (2007). This empirically corrected TOMS data (EP-TOMS V8-corrected) has been made available since September 2007. The recent paper of Antón et al. (2010) presented the global comparisons between the TOC satellite observations derived from the V8-original and V8-corrected EP-TOMS data using reliable ground-based measurements as reference.This work showed that EP-TOMS V8-corrected total ozone data present a remarkable improvement concerning the significant negative bias of around ∼3% detected in the EP-TOMS V8-originnal observations after the year 2000.

Solar minimum 2008-2009

The descending phase of solar cycle 23 was long and gradual, and during 2008–2009, solar activity became extremely low. In late 2009, solar activity finally started to increase, but the period between mid-2007 and mid-2009 was one of the longest of recent solar minima. Recently, several interesting papers have been published about this subject. The work of Fröhlich (2010) has shown that the value of total solar irradiance during the solar minimum of 2008-2009 was more than 0.2 Wm−2 smaller than during the last minimum in 1996. Solomon et al. (2010) have indicated that that solar extreme ultraviolet irradiance levels during the solar minimum of 2008-2009 were also lower than they were during the previous solar minimum. Haigh et al. (2010) have shown that these spectral changes appear to have led to a significant decline from 2004 to 2007 in stratospheric ozone below an altitude of 45 km. Garcia (2010) states that these implications for Earth’s atmosphere must be viewed as provisional.

The First WMO Antarctic Ozone Bulletin of 2010

The WMO Antarctic Ozone Bulletin contains information on the state of the ozone layer in the Antarctic at roughly two week intervals from August to November. The bulletins are based on ground-based ozone data provided by WMO Members and satellites to observe ozone globally. The first bulletin in 2010 (7.2 MB) indicates "that the area where total ozone is less than 220 DU (“ozone hole area”) is low compared to recent years", adding that its evolution will depend on the meteorological conditions between now and early October, when depletion usually ends. Thus, "it is still too early to give a definitive statement about the development of this year's ozone hole and the degree of ozone loss that will occur", the bulletin stated.

Influence of ozone mini-holes on UV radiation

The International Journal of Climatology has recently published two papers about the ozone mini-holes effects over the UV radiation. Sola and Lorente study the impact of two mini-holes on erythemal UV irradiance over Barcelona (Spain). They find that this irradiance at noon was 36% higher on 10 January 2004 than the day before. This date corresponds with the minimum total ozone value recorded over the Iberian Peninsula. On the other hand, Martinez-Lozano et al. analyzed the low ozone level episodes over Valencia (Spain) during 2000-2007. The increase of UV radiation related to the decrease in total ozone is quantified at 1.29 times this decrease

The 25 anniversary of the discovery of the Antarctic ozone hole

To mark the 25 anniversary of the discovery of the Antarctic ozone hole, the prestigious journal Nature presents the original research paper reporting the high ozone decline over Antarctica in spring. In addition, a new Opinion piece from one of the paper's authors, plus a collection of related articles that have advanced our understanding of the stratosphere and the ozone layer.

Access selected content from the web focus free online:
the 25 anniversary of the discovery of the Antarctic ozone hole

UV radiation, Ozone and Aerosols over the Iberian Peninsula

The JGR has recently published three papers about these topics. Bilbao and de Miguel (2010) studied an empirical relationship between the solar ultraviolet-B (UV-B) in the range (280–315 nm) and the total global solar irradiation (G) in Valladolid (Spain). The results showed that G is an appropriate variable to obtain UV-B daily values in places where UV radiation is not measured or to extend the existing data set back in time. Mladenove et al. (2010) analyzed the relationships between spectroscopic (fluorescence and absorbance) properties of the water-soluble organic compounds in aerosol deposition and ground-based remote sensing measurements of aerosols in the atmospheric column in Granada (Spain). They found important differences between Saharan- and marine-dominated organic aerosols. Antón et al (2010) compared the total ozone retrieved with the passive DOAS methodology from zenith-sky observations by the SPATRAM spectrometer located in Evora (Portugal) with highly accurate total ozone data retrieved from direct-sun recordings by a well-calibrated Brewer instrument in El Arenosillo (Spain). The results showed that the differences observed between both systems is not associated with the natural spatial variability of the total ozone.

The World Avoided by protecting the ozone layer

There are several very interesting papers in literature that analyse a future world where ozone depleting substances were never regulated by the Montreal Protocol. This protocol signed in 1989 was the first international agreement on regulation of chemical pollutants, and it is widely considered the most successful environmental treaty. Newman et al (ACP, 2009) show that 17% of the globally-averaged column ozone is destroyed by 2020, and 67% is destroyed by 2065 in comparison to 1980. Ozone levels in the tropical lower stratosphere remain constant until about 2053 and then collapse to near zero by 2058. Morgenstern et al. (GRL, 2008) indicate that the Montreal Protocol has not only averted further damage to the ozone layer but has helped prevent significant regional climate change. In this sense, Molina et al. (PNAS, 2009) state that the strengthening of the Montreal Protocol can phase down the production and consumption of hydrofluorocarbons (HFCs) with high global warming potential. According the authors, this and other strategies may reduce the risk of abrupt climate change in the next few decades.

Interesting events in 2010

During the year 2010, there will take place several interesting events related to the Atmospheric Sciences:

- EGU (European Geosciences Union, General Assembly 2010), 2-7 May, Vienna, Austria.

- 37th Annual European Meeting on Atmospheric Studies by Optical Methods , 23-27 August, Valladolid, Spain.

- IAC (International Aerosol Conference) , 29 August- 3 September, Helsinki, Finland.

- SPIE Remote Sensing, 20-23 September, Toulouse, France.

- EUMETSAT Meteorological Satellite Conference, 20-24 September, Cordoba, Spain.

New OMI Ozone Profile data release

OMI Ozone Profile data (OMO3PR) is given in terms of the layer-columns of ozone in Dobson Unit (DU) for an 18-layer atmosphere. The layers are nominally bounded by the pressure levels: surface pressure, 700, 500, 300, 200, 150, 100, 70, 50, 30, 20, 10, 7, 5, 3, 2, 1, 0.5, and 0.3 hPa.

Detailed information about this product can be found at:

OMO3PR README File

Full OMO3PR data, as well as subsets of these data over many ground stations and along Aura validation aircraft flights paths are available through the Aura Validation Data Center (AVDC) website