1. The EISCAT_3D Science Case: Atmospheric Section Ian McCrea STFC RAL

2. Preparatory Phase WP3: Science Case Work Package Engaging with potential new users Holding targeted workshops Gathering requirements for new science Revising/developing the science case Feeding science demands back to radar design Issuing periodic versions of science case, consistent with the PSD

3. The Science Working Group Convenors: Anita Aikio, Ian McCrea 5-10 members at any time Mix of existing and new EISCAT users Membership rotates annually Cover a wide range of science topics Atmospheric science, space weather, modelling... Two meetings with each committee, email exchanges in between

4. Timetable of Activities Current WG members: Mark Clilverd, Markus Rapp, Yasonobu Ogawa, Kjellmar Oksavik, Asta Pellinen-Wannberg. First Meeting: FMI Helsinki 14/1/2011 (also Kirsti Kauristie and Pekka Verronen) Second Meeting: Uppsala 17/5/2011 (also Stephan Buchert and Thomas Leyser) First version of the science case due in Month 9 (July) Next roll of WG: Space Weather and Modelling Annual reports each year Final version of case in month 48

5. Structure of the Science Case Executive Summary Introduction to EISCAT_3D The Science Case: – Atmospheric physics and global change – Space and plasma physics – Solar system science – Space weather and service applications – Radar techniques, coding and analysis

6. Structure of the Atmospheric Section Background Dynamical coupling in the atmosphere Solar-terrestrial effects on atmospheric chemistry Dynamical and chemical coupling in the mesosphere Atmospheric turbulence in the stratosphere and troposphere Short and long-term change in the upper atmosphere

7. Dynamical Coupling in the Atmosphere: Topics Covered Rossby and gravity waves, winds, tides Wave breaking and dissipation Effects on large-scale circulation Consequences for composition and transport

8. Dynamical Coupling in the Atmosphere: Key Science Questions What is the three-dimensional structure of the wave fields propagating upwards from the troposphere? How do their characteristics change as they move upwards to thermospheric heights? How does atmospheric turbulence form and evolve? How is this process different in the different atmospheric layers? What is the relationship between changes in chemistry and changes in dynamics? How do waves and turbulence interact to modify the global-scale circulation of the middle atmosphere? What effects are seen when the normal circulation is disrupted? What is the relationship between the waves generated in the upper atmosphere and the processes which cause them?

9. Solar-terrestrial effects on chemistry: Topics covered Energetic particles and HOx/NOx Modulation of ozone density Links to dynamics Links to surface temperature anomalies D-region chemistry Active experiments on the D-region

10. Solar-terrestrial effects on chemistry: Key Science Questions What are the durations and extents of the energetic particle events which modulate chemistry? How does the wave and tidal climatology change when the heat balance of the middle atmosphere is modulated, for example by changes in chemistry? What processes link these changes to apparent effects at lower altitudes? Can high-resolution continuous observations help validate chemical/dynamical models of the D-region? Can we improve our models through targeted active experiments?

11. Dynamical and Chemical Coupling in the Mesosphere Topics Covered Chemistry and turbulence in mesospheric thin layers Structure and aspect sensitivity in PMSE PMWE: turbulence or dust? Long-term trends Other kinds of D-region fine structure (plasma instabilities)

12. Dynamical and Chemical Coupling in the Mesosphere Key Science Questions How much small-scale structure is contained in mesospheric thin layers? Is this linked to wave activity, or plasma physics, or both? What explains the aspect sensitivity of PMSE and PMWE layers? What is the horizontal and vertical structure of the dust size in PMSE layers, and how does this vary? Are PMWE layers linked to both dust and turbulence, or only to turbulence? How do they form, and what determines when they appear? Are mesospheric thin layers signs of global change, connected to human activity?

13. Stratosphere and Troposphere: Topics Covered Changes in wave propagation Stratospheric warmings Turbulence and wave dissipation Stratosphere/ troposphere exchange processes Atmospheric vorticity

14. Stratosphere and Troposphere: Key Science Questions How does turbulence in the troposhere and stratosphere form and develop? What are the effects of turbulence and wave dissipation on energy exchange between atmospheric layers? How do stratospheric warming events affect the atmosphere at other heights, and at other latitudes? Can the upper atmosphere exert a downward control on the troposphere, and if so how?

15. Short and long-term change: Topics Covered Long-term cooling and contraction of the thermosphere Long-term change in the mesosphere Understanding shorter-term variations Effects on satellite drag Problems with models and predictability

16. Short and long-term change: Key Science Questions How does long-term change in the troposphere affect its energy exchange with the other atmospheric layers? Is greenhouse warming of the lower atmosphere resulting in long- term cooling of the upper atmosphere? If so, what effect is this having? What are the problems with our current models of the upper atmosphere, and what implications might these have for predictability? Can we use EISCAT_3D data as a basis to make improved predictions of shorter-term variations in the Earth’s upper atmosphere, such as those connected to the solar cycle?

17. What happens next? Last meeting with this version of the panel Good discussions yesterday – some work needed to accommodate the changes Continue to work on atmospheric section by email Need to work more on the key science questions Close to final version of atmospheric case by the time of the July submission

18. Things to think about...... Are the section headings correct? Are there major areas missing? Are the key science questions appropriate? Are there important questions missing? Have the questions been answered already? Can EISCAT_3D really make a contribution?