A selection of new science articles from the past week of interest to the SPARC community (a SPARC Office choice).

Data assimilation in atmospheric chemistry models: current status and future prospects for coupled chemistry meteorology models. By M. Bocquet et al. in Atmospheric Chemistry and Physics.

Stratospheric influence on tropospheric jet streams, storm tracks, and surface weather. By J. Kidston et al. in Nature Geoscience.

Polar processing in a split vortex: Arctic ozone loss in early winter 2012/2013. By G.L. Manney et al. in Atmospheric Chemistry and Physics.

Big grains go far: understanding the discrepancy between tephrochronology and satellite infrared measurements of volcanic ash. By J.A. Stevenson et al. in Atmospheric Measurement Techniques.

Sensitivity of Tropical Tropospheric Composition to Lightning NO_x Production as Determined by the NASA GEOS-Replay Model. By C.E. Liaskos et al. in the Journal of Geophysical Research: Atmospheres.

Aircraft measurements of BrO, IO, glyoxal, NO₂, H₂O, O₂–O₂ and aerosol extinction profiles in the tropics: comparison with aircraft-/ship-based in situ and lidar measurements. By R. Volkamer et al. in Atmospheric Measurement Techniques.

Round-robin evaluation of nadir ozone profile retrievals: methodology and application to MetOp-A GOME-2. By A. Keppens et al. in Atmospheric Measurement Techniques.

The Melting Arctic and Mid-latitude Weather Patterns: Are They Connected? By J. Overland et al. in the Journal of Climate.

TTL cooling and drying during the January 2013 Stratospheric Sudden Warming. By S. Evan et al. in the Quarterly Journal of the Royal Meteorological Society.

Evaluation of a regional air quality model using satellite column NO₂: treatment of observation errors and model boundary conditions and emissions. By R.J. Pope et al. in Atmospheric Chemistry and Physics.

A hiatus in the stratosphere? By A.J. Ferraro et al. in Nature Climate Change.

Quasi-biennial oscillation of the tropical stratospheric aerosol layer. By R. Hommel et al. in Atmospheric Chemistry and Physics.

Discussion Papers – Open for comment

The impact of volcanic aerosols on stratospheric ozone and the Northern Hemisphere polar vortex: separating radiative from chemical effects under different climate conditions. By S. Muthers et al. in Atmospheric Chemistry and Physics Discussions.

A selection of new science articles from the past week of interest to the SPARC community (a SPARC Office choice).

Interhemispheric transit-time distributions and path-dependent lifetimes constrained by measurements of SF₆, CFCs, and CFC replacements. By M. Holzer and D.W. Waugh in Geophysical Research Letters.

Revising the slant-column density retrieval of nitrogen dioxide observed by the Ozone Monitoring Instrument. By S. Marchenko et al. in the Journal of Geophysical Research: Atmospheres.

Effect of Recent Sea Surface Temperature Trends on the Arctic Stratospheric Vortex. By C.I. Garfinkel et al. in the Journal of Geophysical Research: Atmospheres.

Growth in stratospheric chlorine from short-lived chemicals not controlled by the Montreal Protocol. By R. Hossaini et al. in Geophysical Research Letters.

Characterization of thermal structure and conditions for overshooting of tropical and extratropical cyclones with GPS radio occultation. By R. Biondi et al. in Atmospheric Chemistry and Physics.

Impact of stratospheric major warmings and the quasi-biennial oscillation on the variability of stratospheric water vapor. By M. Tao et al in the Journal of Geophysical Research: Atmospheres.

Data assimilation of satellite-retrieved ozone, carbon monoxide and nitrogen dioxide with ECMWF’s Composition-IFS. By A. Inness et al. in Atmospheric Chemistry and Physics.

The onset of the barotropic sudden warming in a global model. By Y.S. Liu and R.K. Scott in the Quarterly Journal of the Royal Meteorological Society.

Measuring and modeling the lifetime of Nitrous Oxide including its variability. By M.J. Prather et al. in the Journal of Geophysical Research: Atmospheres.

Participation deadline: 20 May 2015 – extended to 3 June 2015

The ROM SAF is a decentralized facility under EUMETSAT which runs an operational radio occultation (RO) system. We are conducting this survey in order to gather information and recommendations from users related to possible future RO products and activities to be pursued by the ROM SAF in coordination with EUMETSAT.

The ROM SAF is responsible for delivering bending angle, refractivity, temperature, pressure, humidity profiles, and other radio occultation data in near-real time and offline for NWP and climate users. The offline profiles are further processed into climate products consisting of
e.g. gridded monthly means of bending angle, refractivity, temperature, humidity, and geopotential heights. The ROM SAF also maintains the ROPP (Radio Occultation Processing Package) software package for users wishing to process, quality-control, and assimilate radio occultation data from any radio occultation mission into NWP and other models.

For more information please consult our website: http://www.romsaf.org.

The results of the User Survey will be compiled into a report which will be made available from our website.

If you wish to participate, please follow this link:
http://www.romsaf.org/usersurveys/us4/

The User Survey will close on May 20, 2015.

Contact person:
Johannes K. Nielsen

A selection of new science articles from the past week of interest to the SPARC community (a SPARC Office choice).

Temperature Variation over East Asia during the lifecycle of weak stratospheric polar vortex. By S.-H. Woo et al. in the Journal of Climate.

Modulation of Antarctic vortex composition by the Quasi-Biennial Oscillation. By S.E. Strahan et al. in Geophysical Research Letters.

Observations of planetary waves in the mesosphere-lower thermosphere during stratospheric warming events. By N.H. Stray et al. in Atmospheric Chemistry and Physics.

Air-Mass Origin in the Tropical Lower Stratosphere: The Influence of Asian Boundary Layer Air. By C. Orbe et al. in Geophysical Research Letters.

Using self-organising maps to explore ozone profile validation results – SCIAMACHY limb compared to ground-based lidar observations. By J.A.E. van Gijsel et al. in Atmospheric Measurement Techniques.

Signatures of the 2-day wave and sudden stratospheric warmings in Arctic water vapour observed by ground-based microwave radiometry. By B. Tschanz and N. Kämpfer in Atmospheric Chemistry and Physics.

An adaptive covariance relaxation method for ensemble data assimilation. By Y. Ying and F. Zhang in the Quarterly Journal of the Royal Meteorological Society.

Influence of isoprene chemical mechanism on modelled changes in tropospheric ozone due to climate and land use over the 21^st century. By O.J. Squire et al. in Atmospheric Chemistry and Physics.

Discussion Papers – open for comment

Effect of tropical cyclones on the tropical tropopause parameters observed using COSMIC GPS RO data. By S. Ravindra Babu et al. in Atmospheric Chemistry and Physics Discussions.

Global temperature response to the major volcanic eruptions in multiple reanalysis datasets. By M. Fujiwara et al. in Atmospheric Chemistry and Physics Discussions.

High resolution radiosonde data from US Radiosonde Replacement System (RRS) stations are now available directly from NOAA’s National Centers for Environmental Information at ftp://ftp.ncdc.noaa.gov/pub/data/rrs-data/. Data are available in BUFR format at 1-second resolution for all US stations from the time at which each station was upgraded to the RRS up to the present (earliest data available from 2005).

Radiosonde data at 6-second resolution from US stations prior to RRS upgrade are still available from the SPARC Data Center at http://www.aparc-climate.org/data-center/data-access/us-radiosonde/.

Deadline for registration and abstract submission: 17 June 2015

The 8th International Atmospheric Limb Workshop will be hosted by The Department of Earth and Space Sciences at Chalmers University of Technology.

Scientific Focus:

• Limb measurements: Emission (UV, visible, IR, microwave), occultation (solar, stellar, lunar), scattering
• Past, current and future spaceborne instruments: SMR, OSIRIS, ACE, GOMOS, MIPAS, SCIAMACHY, SMILES, SAGE, SABER, MLS, SOFIE, HIRDLS, OMPS, ALTIUS, MATS, STEAM
• Observations and modelling: Mesosphere and above, stratosphere, UTLS and troposphere
• Retrieval algorithms and data assimilation
• Radiative transfer and spectroscopy

Contact:

Find website.

A selection of new science articles from the past week of interest to the SPARC community (a SPARC Office choice).

Evolving obs4MIPs to Support the Sixth Coupled Model Intercomparison Project (CMIP6). By R. Ferraro et al. in the Bulletin of the American Meteorological Society.

Mountain waves and wakes generated by South Georgia: implications for drag parametrization. By S.B. Vosper in the Quarterly Journal of the Royal Meteorological Society.

Reconciling reported and unreported HFC emissions with atmospheric observations. By M.F. Lunt et al. in Proceedings of the National Academy of Sciences of the United States of America.

Possible impacts of a future Grand Solar Minimum on climate: Stratospheric and global circulation changes. By A.C. Maycock et al. in the Journal of Geophysical Research: Atmospheres.

Tropopause Folds in ERA-Interim: Global Climatology and Relation to Extreme Weather Events. By B. Škerlak et al. in the Journal of Geophysical Research: Atmospheres.

Discussion Papers – open for comment

A solar signal in lower stratospheric water vapour? By T. Schieferdecker et al. in Atmospheric Chemistry and Physics Discussions.

Trajectory mapping of middle atmospheric water vapor by a mini network of NDACC instruments. By M. Lainer et al. in Atmospheric Chemistry and Physics Discussions.

Pre-proposals deadline: 1 June 2015

2015 International Opportunities Fund: climate predictability and inter-regional linkages

The Belmont Forum and JPI Climate have launched a call for funding pre-proposals on climate predictability and inter-regional linkages (drivers and mechanisms linking poles & monsoons for societal usefulness of climate services).

This call aims to support medium-size research projects of 3-4 years duration, and recommends a budget of between 1 and 3 M Euros.

Pre-proposals are due by June 1st 2015, and interested researchers are strongly advised to use the online research matching tool.

Find out more here:

http://www.futureearth.org/news/call-proposals-climate-predictability-and-inter-regional-linkages

Deadline for applications for support: 15 May 2015
Deadline for abstract submission: 22 May 2015

The website for registration and abstract submission is now open for the open meeting titled "Composition and Transport in the Tropical Troposphere and Lower Stratosphere" to be held in Boulder, CO on 20-23 July, 2015:

http://esrl.noaa.gov/csd/events/CT3LS/

The meeting will cover the role of the TTL in the climate system and the response of the TTL to future climate change. Susan Solomon and Graeme Stephens have kindly agreed to give invited talks. One aim is to identify open science questions and the future measurement strategies needed to address them, and all participants will be encouraged to come prepared.

The meeting will cover the science topics listed below and include oral and poster presentations. Analyses that combine ground-based, airborne, and satellite measurements, as well as the use of these observations for evaluation of large-scale models, are particularly welcome.

Science topics:

1. Chemistry and transport processes controlling tropical tropospheric and stratospheric composition
2. Measurement and model comparisons
3. Clouds and water vapor

The deadline for abstract submission is May 22, 2015.

Limited support will be available for international participants and for students.
The deadline for applications for support is May 15, 2015.
See the website for more details.

This meeting is held under the auspices of SPARC and IGAC.

Organising committee:

Joan Alexander, Elliot Atlas, Neil Harris, Fumio Hasebe, Eric Jensen, Nathaniel Livesey, Rolf Müller, Laura Pan, Leonhard Pfister, Ross Salawitch, and Troy Thornberry.

Please contact Neil Harris (), Troy Thornberry (), or Eric Jensen () with any questions.

A selection of new science articles from the past week of interest to the SPARC community (a SPARC Office choice).

Lidar observations of gravity wave activity in the middle atmosphere over Davis (69°S, 78°E), Antarctica. By B. Kaifler et al. in the Journal of Geophysical Research: Atmospheres.

The impact of current CH₄ and N₂O atmospheric loss process uncertainties on calculated ozone abundances and trends. By E.L. Fleming et al. in the Journal of Geophysical Research: Atmospheres.

Climate intercomparison of GPS radio occultation, RS90/92 radiosondes and GRUAN from 2002 to 2013. By F. Ladstädter et al. in Atmospheric Measurement Techniques.

The decrease in mid-stratospheric tropical ozone since 1991. By G.E. Nedoluha et al. in Atmospheric Chemistry and Physics.

Distributions of ice supersaturation and ice crystals from airborne observations in relation to upper tropospheric dynamical boundaries. By M. Diao et al. in the Journal of Geophysical Research: Atmospheres.

Discussion Papers – open for comment

Solar geoengineering using solid aerosol in the stratosphere. By D.K. Weisenstein and D.W. Keith in Atmospheric Chemistry and Physics Discussions.

Impact of ozone observations on the structure of a tropical cyclone using coupled atmosphere–chemistry data assimilation. By S. Lim et al. in Atmospheric Chemistry and Physics Discussions.