T. Trickl and co-authors have just published an ACP paper looking at 35 years of stratospheric aerosol measurements taken at Garmisch-Partenkirchen, Germany. They focused largely on the volcanically quiescent period of 1995-2006 to investigate the processes maintaining a residual lower stratospheric aerosol layer. Their results indicate that the influence of air traffic on stratospheric aerosol loading is small and that although single, large forest-fire events could be noticed, overall biomass burning also seems to have a limited impact on the stratospheric background aerosol. Post 2008 they observed an increase in backscatter coefficients largely due to mid-sized (explosivity index 4) volcanic eruptions, most of which occurred in the mid-latitudes. Find the full abstract here.

G. Kirgis and co-authors recently published a paper in ACP regarding the interannual variability of stratospheric ozone at Mauna Loa, Hawaii, and Table Mountain, California. They used a multi-linear regression analysis on monthly mean lidar and satellite profile data between 20-45km from the volcanically quiescent period of January 1995 to April 2011. Results were consistent with recent model simulations indicating changes in tropical upwelling. They found a net increase and sign of ozone recovery after 2005. Find the full abstract here.

In their recent ACPD article, A.Y. Park and co-authors take a statistical look at Umkehr ozone profiles at Boulder, USA, and Arosa, Switzerland. Using principal component analysis and a number basis functions they found that they could accurately capture fine variations in the time evolutions of ozone profiles. At Boulder, strongly declining trends from 2003-2011 at altitudes of 64-32hPa were found, indicating that stratospheric ozone over this region is not yet fully recovering. Find the full abstract here.

In a recent Journal of Geophysical Research paper, S.M. Päivärinta and colleagues investigated the effects of solar proton events (SPEs) and sudden stratospheric warmings (SSWs) on odd nitrogen and ozone in the polar middle atmosphere using observations from ACE-FTS, MLS/Aura and SABER/TIMED. Considering three different winters, 2005 (with an SPE), 2009 (with an SSW), and 2012 (with SPEs and SSW), they found that NOx increases after both SPEs and SSWs by up to a factor of 25 between 40-90km. As a result of the enhanced NOx concentrations, strong ozone depletion occurred. Find the full abstract here.

A validation article by M. Diao and co-authors, published in the Journal of Geophysical Research, makes a comparison between AIRS/AMSU-A water vapour and temperature data with in situ aircraft measurements in the UTLS. They found that the absolute percentage difference between satellite and aircraft observations ranged between 20-60% and 1.0-2.5K, for water vapour and temperature observations, respectively. Land retrievals were found to be biased colder and drier than ocean retrievals at the UTLS, and no significant difference between hemispheres was found. Find the full abstract here.

The symposium NCGG7 will take place in Amsterdam, The Netherlands, 5-7 November 2014.

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The Master programme on Climate and Atmospheric Science at the University of Leeds is specifically designed to provide a springboard for students who are keen to pursue a research-focussed career (but not necessarily a PhD).

Note that the deadline for scholarships is on 31 May 2013.

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Data products are now available of ozone, water vapour, nitric acid and nitrous oxide.

The Goddard Earth Sciences Data and Information Services Center (GES DISC), in collaboration with Principal Investigator Lucien Froidevaux, is pleased to announce the release of the ozone (O₃), water vapor (H₂O), nitric acid (HNO₃) and nitrous oxide (N₂O) zonal means data products from the "Global Ozone Chemistry and Related trace gas Data Records for the Stratosphere (GOZCARDS)" project, part of the NASA Making Earth Science Data Records for Use in Research Environments (MEaSUREs) Program. These products include monthly merged and source data for the above species (with start year being 1979 for O₃, and later for other species).

Additionally, data for 2011 and 2012 from the previously released hydrogen chloride (HCl) and “MERRA-based” temperature (T) zonal mean data products are now available.

Other GOZCARDS products are planned for later in 2013. Users should review the README document for additional information. Information on these data, including the README document, and access to the data are available at http://disc.sci.gsfc.nasa.gov/datareleases/measures-gozcards-data-now-available.

See also the JPL website at http://gozcards.jpl.nasa.gov.

In their JGR article, Koji Imai and numerous SPARC scientists as co-authors, present validation studies of ozone profiles in the middle atmosphere.

The data was taken by Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) onboard the International Space Station ISS from October 2009 to April 2010. Comparisons of the data with satellite observations and chemistry-transport models indicate that the observations agree generally within 10%. The SMILES data also capture diurnal variability well.

Find the full article here.

In their JGR article authored by SOLARIS-HEPPA activity leader Katja Matthes and colleagues, the results are presented from multi-decadal sensitivity experiments with time-varying solar cycle and Quasi-Biennial Oscillation (QBO) forcings.

Multi-decadal simulations using the NCAR’s Whole Atmosphere Community Climate Model (WACCM3.1) were carried out to assess the time-varying forcing of solar variability and the QBO. In the tropical upper stratsphere the annual mean solar response is found to be independent of the presence of the QBO. Only the experiment including both solar and QBO forcing agrees reasonably with observations, indicating that both forcings are necessary to realistically simulating the climate. The QBO is also found to modulate the background zonal mean wind climatology, which in turn modifies the modelled solar signal.

Find the full article here.