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.

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.

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/

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

Thunderstorms enhance tropospheric ozone by wrapping and shedding stratospheric air. By L.L. Pan et al. in Geophysical Research Letters.

Total volcanic stratospheric aerosol optical depths and implications for global climate change. By D.A. Ridley et al. in Geophysical Research Letters.

Airborne verification of CALIPSO products over the Amazon: a case study of daytime observations in a complex atmospheric scene. By F. Marenco et al. in Atmospheric Chemistry and Physics.

Biogenic SOA formation through gas-phase oxidation and gas-to-particle partitioning – a comparison between process models of varying complexity. By E. Hermansson et al. in Atmospheric Chemistry and Physics.

Application of GPS radio occultation to the assessment of temperature profile retrievals from microwave and infrared sounders. By M. Feltz et al. in Atmospheric Measurement Techniques.

Recalibration and Merging of SSU Observations for Stratospheric Temperature Trend Studies. By C.-Z. Zou et al. in the Journal of Geophysical Research: Atmospheres.

Improving stratospheric transport trend analysis based on SF₆ and CO₂ measurements. By. E.A. Ray et al. in the Journal of Geophysical Research: Atmospheres.

Variability of Antarctic ozone loss in the last decade (2004–2013): high resolution simulations compared to Aura MLS observations. By J. Kuttippurath et al. in Atmospheric Chemistry and Physics Discussions.

Satellite observations of stratospheric carbonyl fluoride. By J.J. Harrison et al. in Atmospheric Chemistry and Physics.

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

Total volcanic stratospheric aerosol optical depths and implications for global climate change. By D.A. Ridley et al. in Geophysical Research Letters.

Denitrification by large NAT particles: the impact of reduced settling velocities and hints on particle characteristics. By W. Woiwode et al. in Atmospheric Chemistry and Physics.

Variations of stratospheric water vapor over the past three decades. By A.E. Dessler et al. in the Journal of Geophysical Research: Atmospheres.

Recent Northern Hemisphere stratospheric HCl increase due to atmospheric circulation changes. By E. Mahieu et al. in Nature.

Lidar-observed enhancement of aerosols in the upper troposphere and lower stratosphere over the Tibetan Plateau induced by the Nabro volcano eruption. By Q.S. He et al. in Atmospheric Chemistry and Physics.

MIPAS temperature from the stratosphere to the lower thermosphere: Comparison of vM21 with ACE-FTS, MLS, OSIRIS, SABER, SOFIE and lidar measurements. By M. García-Comas et al. in Atmospheric Measurement Techniques.

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

An Objective Analysis of the QBO in ERA-Interim and the Community Atmosphere Model, Version 5. By A. Solomon et al. in Geophysical Research Letters.

The relevance of the location of blocking highs for stratospheric variability in a changing climate. By B. Ayarzagüena et al. in the Journal of Climate.

Can inertia-gravity waves persistently alter the tropopause inversion layer? By D. Kunkel et al. in Geophysical Research letters.

Signatures of Naturally Induced Variability in the Atmosphere using Multiple Reanalysis Datasets. By D.M. Mitchell et al. in the Quarterly Journal of the Royal Meteorological Society.