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

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

Signatures of the two 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 Discussions.

Increase in upper tropospheric and lower stratospheric aerosol levels and its potential connection with Asian Pollution. By J.-P. Vernier et al. in the Journal of Geophysical Research: Atmospheres.

Climatology and variability of trace gases in extratropical double-tropopause regions from MLS, HIRDLS and ACE-FTS measurements. By M.J. Schwartz et al. in the Journal of Geophysical Research: Atmospheres.

Stratospheric dynamics and midlatitude jets under geoengineering with space mirrors, and sulfate and titania aerosols. By A.J. Ferraro et al. in the Journal of Geophysical Research: Atmospheres.

The diurnal variation in stratospheric ozone from the MACC reanalysis, the ERA-Interim reanalysis, WACCM and Earth observation data: characteristics and intercomparison. By A. Schanz et al. in Atmospheric Chemistry and Physics Discussions.

Lagrangian analysis of microphysical and chemical processes in the Antarctic stratosphere: a case study. By L. Di Liberto et al. in Atmospheric Chemistry and Physics Discussions.

The impact of polar stratospheric ozone loss on Southern Hemisphere stratospheric circulation and climate. By J. Keeble et al. in Atmospheric Chemistry and Physics.

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 Discussions.

Tracing the second stage of ozone recovery in the Antarctic ozone-hole with a "big data" approach to multivariate regressions. By A.T.J. de Laat et al. in Atmospheric Chemistry and Physics.

Stratospheric volcanic ash emissions from the 13 February 2014 Kelut eruption. By N.I. Kristiansen et al. in Geophysical Research Letters.

Particulate matter, air quality and climate: lessons learned and future needs. By S. Fuzzi et al. in Atmospheric Chemistry and Physics Discussions.

Deadline for grant applications: 15 Jan 2015
Deadline for abstracts: 31 Jan 2015

Conveners:
Daniel Marsh (Boulder, USA), Ulrike Langematz (Berlin, Germany), William Ward (Fredericton, Canada), Franz-Josef Lübken (Kühlungsborn, Germany)

Description:

This is the core symposium of ICMA (International Commission on the Middle Atmosphere).
Papers related to any aspect of the dynamics, chemistry, or physics of the atmosphere from near the tropopause to the lower thermosphere are appropriate for this symposium.

Observational, modeling, theoretical, and laboratory studies are all solicited. Research topics include (but are not limited to):

• stratospheric/mesospheric chemistry and ozone radiation, microphysics,
• chemistry and dynamics in the TTL or the extratropical UTLS
• dynamics, transport and mixing in multiple spatial scales observations
• and modeling of gravity waves intraseasonal and interannual variations
• in the middle atmosphere remote influences in the middle atmosphere,
• including tropical/extratropical interactions
• vertical coupling with the troposphere and thermosphere.

We especially invite contributions related to the ROSMIC element of the SCOSTEP VarSITI programme to this symposium.

Website:
http://www.iugg2015prague.com

Deadline for grant applications:
15 January 2015

Deadline for abstracts:
31 January 2015

Contact details:
Atmospheric Chemistry Division
National Center for Atmospheric Research
P.O. Box 3000
Boulder, Colorado 80307-3000
phone: +1 303 497-1160
fax: +1 303 497-1400
email:

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

Technical Note: Reanalysis of upper troposphere humidity data from the MOZAIC programme for the period 1994 to 2009. By H.G. Smit et al. in Atmospheric Chemistry and Physics.

Energetic particle induced inter-annual variability of ozone inside the Antarctic polar vortex observed in satellite data. By T. Fytterer et al. in Atmospheric Chemistry and Physics Discussions.

Gravity waves simulated by high-resolution Whole Atmosphere Community Climate Model. By H.-J. Liu et al. in Geophysical Research Letters.

The hydrological sensitivity to global warming and solar geoengineering derived from thermodynamic constraints. By A. Kleidon et al. in Geophysical Research Letters.

A cautionary note on the use of EESC-based regression analysis for ozone trend studies. By J. Kuttippurath et al. in Geophysical Research Letters.

Regional Structure of the Indian Summer Monsoon in Observations, Reanalysis, and Simulation. By B.A. Cash et al. in the Journal of Climate.

Bromine partitioning in the tropical tropopause layer: implications for stratospheric injection. By R.P. Fernandez et al. in Atmospheric Chemistry and Physics.

Reevaluation of stratospheric ozone trends from SAGE II data using a simultaneous temporal and spatial analysis. By R.P. Damadeo et al. in Atmospheric Chemistry and Physics.

Variability of stratospheric mean age of air and of the local effects of residual circulation and eddy mixing. By F. Ploeger et al. in the Journal of Geophysical Research: Atmospheres.

A review of Stratospheric Sounding Unit radiance observations for climate trends and reanalyses. By J. Nash and R. Saunders in the Quarterly Journal of the Royal Meteorological Society.

Variability and trends in dynamical forcing of tropical lower stratospheric temperatures. By S. Flueglistaler et al. in Atmospheric Chemistry and Physics.

Reference quality upper-air measurements: GRUAN data processing for the Vaisala RS92 radiosonde. By R.J. Dirksen et al. in Atmospheric Measurement Techniques.

Middle-atmospheric zonal and meridional wind profiles from polar, tropical and midlatitudes with the ground-based microwave Doppler wind radiometer WIRA. By R. Rüfenacht et al. in Atmospheric Measurement Techniques.

Intercomparison of stratospheric gravity wave observations with AIRS and IASI. By L. Hoffmann et al. in Atmospheric Measurement Techniques.

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

Rapid transport of East Asian pollution to the deep tropics. By M.J. Ashford et al. in Atmospheric Chemistry and Physics.

Stratospheric ozone depletion from future nitrous oxide increases. By W. Wang et al. in Atmospheric Chemistry and Physics.

On the hiatus in the acceleration of tropical upwelling since the beginning of the 21st century. By J. Aschmann et al. in Atmospheric Chemistry and Physics.

The use of SMILES data to study ozone loss in the Arctic winter 2009/2010 and comparison with Odin/SMR data using assimilation techniques. By K. Sagi et al. in Atmospheric Chemistry and Physics.

The impact of volcanic aerosol on the Northern Hemisphere stratospheric polar vortex: mechanisms and sensitivity to forcing structure. By M. Toohey et al. in Atmospheric Chemistry and Physics.

Solar cycle in current reanalyses: (non)linear attribution study. By A. Kuchar et al. in Atmospheric Chemistry and Physics Discussions.

Iodine chemistry in the troposphere and its effect on ozone. By A. Saiz-Lopez et al. in Atmospheric Chemistry and Physics.

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

Stratospheric lifetime ratio of CFC-11 and CFC-12 from satellite and model climatologies. By L. Hoffmann et al. in Atmospheric Chemistry and Physics.

Simulation of the isotopic composition of stratospheric water vapour – Part 2: Investigation of HDO/H₂O variations. By R. Eichinger et al. in Atmospheric Chemistry and Physics Discussions.

Impacts of 20th century aerosol emissions on the South Asian monsoon in the CMIP5 models. By L. Guo et al. in Atmospheric Chemistry and Physics Discussions.

Multistation intercomparison of column-averaged methane from NDACC and TCCON: impact of dynamical variability. By A. Ostler et al. in Atmospheric Measurement Techniques.

Analysis of internal gravity waves with GPS RO density profiles. By P. Šácha et al. in Atmospheric Measurement Techniques.

Fast transport from Southeast Asia boundary layer sources to northern Europe: rapid uplift in typhoons and eastward eddy shedding of the Asian monsoon anticyclone. By B. Vogel et al. in Atmospheric Chemistry and Physics.

Trends in peroxyacetyl nitrate (PAN) in the upper troposphere and lower stratosphere over southern Asia during the summer monsoon season: regional impacts. By S. Fadnavis et al. in Atmospheric Chemistry and Physics.

9-10 April 2015 in Victoria, BC, Canada

The SPARC Temperature Trends​ Activity will hold an open meeting April 9-10 in Victoria, BC, Canada​, on the general topic of observed and modeled stratospheric temperature changes​. (See http://www.aparc-climate.org/activities/temperature-trends/ for a brief summary of the activity).

The ​meeting will focus on two general themes:

1. Understanding the differences between observed and simulated stratospheric temperature variability and trends;
2. Planning the future of the temperature trends activity in the context of the broader SPARC goals and plans.

The meeting is open, but space is limited to ~50 attendees​. Persons ​interested in attending​ should​ contact the co​-​chairs
(Bill Randel, Dian Seidel and Dave Thompson) and local organizing committee (Nathan Gillett​)​ as soon as possible.​

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

The impact of temperature resolution on trajectory modelling of stratospheric water vapour. By T. Wang et al. in Atmospheric Chemistry and Physics Discussions.

Global emissions of refrigerants HCFC-22 and HFC-134a: Unforeseen seasonal contributions. By B. Xiang et al. in Proceedings of the National Academy of Sciences of the United States of America.

Direct and ozone-mediated forcing of the Southern Annular Mode by greenhouse gases. By O. Morgenstern et al. in Geophysical Research Letters.

Global Hawk dropsonde observations of the Arctic atmosphere obtained during the Winter Storms and Pacific Atmospheric Rivers (WISPAR) field campaign. By J.M. Intrieri et al. in Atmospheric Measurement Techniques.

Global Atmospheric Sulfur Budget under Volcanically Quiescent Conditions: Aerosol-Chemistry-Climate Model Predictions and Validation. By J.-X. Sheng et al. in the Journal of Geophysical research: Atmospheres.

The POLARCAT Model Intercomparison Project (POLMIP): overview and evaluation with observations. By L.K. Emmons et al. in Atmospheric Chemistry and Physics Discussions.

Characteristics of tropopause parameters as observed with GPS radio occultation. By T. Rieckh et al. in Atmospheric Measurement Techniques.

Assimilation of GNSS radio occultation observations in GRAPES. By Y. Liu and J. Xue in Atmospheric Measurement Techniques.

Inorganic chlorine variability in the Antarctic vortex and implications for ozone recovery. By S.E. Strahan et al. in the Journal of Geophysical research: Atmospheres.

Validation of MIPAS IMK/IAA V5R_O3_224 ozone profiles. By A. Laeng et al. in Atmospheric Measurement Techniques.

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

Transition from geostrophic turbulence to inertia–gravity waves in the atmospheric energy spectrum. By J. Callies et al. in the Proceedings of the National Academy of Sciences of the United States of America.

Modeling the climate impact of Southern Hemisphere ozone depletion: The importance of the ozone dataset. By P.J. Young et al. in Geophysical Research Letters.

Hemispheric distributions and inter-annual variability of NO_y produced by Energetic Particle Precipitation in 2002–2012. By B. Funke et al. in the Journal of Geophysical Research: Atmospheres.

Quantifying the value of redundant measurements at GCOS Reference Upper-Air Network sites. By F. Madonna et al. in Atmospheric Measurement Techniques.

Characteristics and sources of gravity waves observed in noctilucent cloud over Norway. By T.D. Demissie et al. in Atmospheric Chemistry and Physics.

Antarctic ocean and sea ice response to ozone depletion: a two timescale problem. By D. Ferreira et al. in the Journal of Climate.

Cirrus and water vapour transport in the tropical tropopause layer – Part 2: Roles of ice nucleation and sedimentation, cloud dynamics, and moisture conditions. By T. Dinh et al. in Atmospheric Chemistry and Physics.

Is the residual vertical velocity a good proxy for stratosphere-troposphere exchange of ozone? By J. Hsu and M.J. Prather in Geophysical Research Letters.

26-31 July 2015, Santa Fe, New Mexico, USA

This multidisciplinary conference will explore the state of the science and identify future research directions relevant to the issue of tropical belt widening.

A particular emphasis will be cross-fertilization among the wide range of climate scientists contributing to our understanding of the problem.

Four main themes are planned:
1. What determines the width of the tropical belt?
2. How and why has the tropical width changed in the past?
3. How and why might the tropical width change in the future?
4. What are the impacts for the oceans, cryosphere, hydrologic cycle, human society, and ecosystems?

Conference details are at chapman.agu.org/tropics/

Deadline for abstracts: 12 Dec 2014

16-18 March 2015, Victoria BC, Canada

The objective of the QBO Modelling and Reanalyses Workshop is to better understand the QBO in observations and reanalyses and to improve the fidelity of tropical stratosphere variability in present-day GCMs. The Workshop will (1) evaluate present-day QBO variability in observations and models, and (2) design joint numerical experiments following an active discussion of modelling groups.

The meeting will be tightly focussed, with invited and contributed science presentations and planned experiment discussions. Please register your interest for the Workshop online by following the link below, although numbers are limited. There is no Workshop fee.

The Workshop is an outflow of the QBOi activity and the QBO and Tropical Variability chapter of the SPARC S-RIP Report. The Workshop is kindly sponsored by the UK National Environmental Research Council and SPARC.

To find out more, please visit the Workshop homepage.