From CAWSES

Contents 1 How will Geospace Respond to a Changing Climate? 1.1 Introduction 1.2 Scientific issues 1.3 Upcoming Meetings 1.4 Past Meetings 1.5 Latest publications 1.6 Key Linkages

How will Geospace Respond to a Changing Climate?

Co-leaders:

• Jan Lastovicka (CZ)
• Daniel Marsh (US)

Introduction

Radiative, chemical, and dynamical forcing from below contributes to disturbances of the upper atmosphere. In response to rising greenhouse gas concentrations, cooling in the middle atmosphere will alter the complex physical and chemical processes of this region. Patterns of cooling and contraction of the upper atmosphere are emerging from model studies and observations, consistent with a strong connection to changes in the lower atmosphere. Recent changes in noctilucent cloud distributions, now observed on a global scale by the AIM satellite, are thought to be symptomatic of cooling temperatures in the upper atmosphere. Rising greenhouse gas concentrations alter the ionosphere in a variety of ways and could be transmitted to the magnetosphere. These changes may have unforeseen consequences for space-related technologies and societal infrastructures

Scientific issues

Task Group 2 will focus on answering these three key questions over the next 4 years:

1. How do changes in tropospheric wave generation and their propagation through a changing atmosphere affect the dynamics of the MLT?

2. By how much is the anthropogenic effect on the ionosphere/thermosphere enhanced during a quiet sun period?

3. Are PMC/NLC characteristics trending?

To answer these questions, five projects are established characterize and understand the impacts of:

Project 1.1 Changes in wave sources

storm tracks, mountain waves, convection and stratospheric heating rates

• Project leaders: Jadwiga (Yaga) Richter (US), Kaoru Sato (JP)

• Project members: J. Bacmeister (US), S. Eckermann (US), M. Ern (DE), P. Kushner (CA), P. Preusse (DE), H. Schmidt (DE), R. A. Vincent (AU), S. Watanabe (JP)

Project 1.2 Changes in filtering

Changes of background winds due to CO2 trends and ozone layer changes

• Project leaders: Elisa Manzini (IT), S. Eckermann (US)
• Project members: V. Ratnam (IN), P. Espy (NO), Y. Kawatani (JP), E. Becker (DE), N. Harnik (IL)

Project 1.3 Changes in MLTI dynamics and composition

• Project leaders: G. Beig (IN), C. Jacobi (DE)
• Project members: C. Arras (DE), M.Bittner (DE), K. Höppner (DE), J.Scheer (AR), S.Gurubaran (IN), A. Manson (CA), C. Meek (CA), D.Murphy (AU) J. Lastovicka (CZ), P. Mukhtarov (BG), E. Merzlyakov (RU), D.Pancheva (BG), A. Pogoreltsev (RU)

Project 2 The enhancement of the anthropogenic effect on the ionosphere/thermosphere during a quiet sun period.

• Project leaders: J. Emmert (US), L. Qian (US)
• Project members: L. Alfonsi (Italy), A. Elias (Argentina), M. Mlynczak (US), S. Nossal (US), H. Schmidt (DE), S.-R. Zhang (US)

Project 3 PMC/NLC altitude, frequency and brightness changes related to changes in dynamics and chemical composition.

• Project leaders: G.E. Thomas (US), U. Berger (DE)
• Project members: M. DeLand (US), , B. Karlsson (Sweden), S. Kirkwood (Sweden), A. Klekociuk (Australia), A. Merkel (US), N. Pertsev (RU)

Upcoming Meetings

Second CAWSES-2 Task 2 Workshop: Modeling Polar Mesospheric Cloud Trends, May 3-4, 2012 Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, USA.

7th IAGA/ICMA/CAWSES Workshop on Long-Term Changes and Trends in the Atmosphere, which will be held in September 2012, in Buenos Aires, Argentina [1]

Past Meetings

The 6th IAGA/ICMA/CAWSES workshop on “Long-Term Changes and Trends in the Atmosphere” (http://www.hao.ucar.edu/TREND2010/index.php) was held at National Center for Atmospheric Research (NCAR) Center Green Conference Center, Boulder, Colorado, USA, June15-18, 2010, the week before the 2010 CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions) workshop, which was also held in Boulder.

AGU Chapman Conference on Atmospheric Gravity Waves and Their Effects on General Circulation and Climate Honolulu, Hawaii, 28 February – 4 March 2011 [2]

Latest publications

U. Berger and F.- J. Lübken, Mesospheric temperature trends at mid-latitudes in summer, Geophys. Res. Lett., L22804, doi:10.1029/2011GL049528, 2011[3].

A. K. Smith, R. R. Garcia, D. R. Marsh, D. E. Kinnison, and J. H. Richter, Simulations of the response of mesospheric circulation and temperature to the Antarctic ozone hole, Geophys. Res. Lett., 37, L22803, doi:10.1029/2010GL045255, 2010[4]

Special Section Title: “Long-term changes in the stratosphere, mesosphere, thermosphere, and ionosphere” Journal of Geophysical Research, vol. 116, no. , 2011 Guest Editor(s): J. Emmert, G. Beig [5]

Key Linkages

• Cross-task project with Task Group 4 (project 5)