Neutral Atmosphere Density Interdisciplinary Research: (NADIR)

1. Predicted Position Actual Position Neutral Atmosphere Density Interdisciplinary Research: (NADIR) A Multidisciplinary University Research Initiative (MURI) Sponsored by the Air Force Office of Scientific Research The objective of NADIR is to significantly advance understanding of drag forces on satellites, including density, winds, and factors affecting the drag coefficient. We seek a level of understanding that will enable specification and prediction at the “next level” of performance. Co-Principal Investigators:Jeff Forbes and Tim Fuller-Rowell University of Colorado at Boulder Aug 2007 - Aug 2012 $7.2 M http://ccar.colorado.edu/muri/ AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

2. AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

3. NADIR Participants • Collaborators • Jeffrey Anderson, NCAR • Eugene Avrett, Harvard-SAO • Christopher Bass, AFSPC • Bruce Bowman, AFSPC • Gary Bust, UTSA • Mihail Codrescu, SEC, NOAA • Doug Drob, NRL • Irene Gonzalez-Hernandez, NSO • Cheryl Huang, AFRL • Chin Lin, AFRL • Charles Lindsey, Co-RA • Frank Marcos, AFRL • Matthew McHarg, USAFA • Craig McLaughlin, U Kansas • Cliff Minter, NGA • Steve Nerem, CU • Andrew Nicholas, NRL • Jens Oberheide, U Wuppertal • Vic Pizzo, SEC, NOAA • Eric Quemaris, CNRS • Arthur Richmond, NCAR • Stan Solomon, NCAR • Thomas Woods, CU Co-Investigators • Rashid Akmaev, • Brian Argrow, • George Born, • Geoff Crowley, • David Falconer, • Delores Knipp, USAFA • Juan Fontenla, • Tomoko Matsuo, • Dusan Odstrcil, • Joachim Raeder, • Jeff Thayer, Administration Sarah Melssen, CU DoD Oversight Kent Miller, AFOSR; Joseph Liu, AFSPC; Robert McCoy, ONR AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

4. 1000 km AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

5. NADIR Methodology • Better understand the • physical processes • Determine which of the • processes create structure • on a scale that is important • to satellite drag. • Determine the driver-response relationships - internal and external. • Improve forecasts of the drivers. • Determine the most valuable datasets required to specify the system state and forecast the drivers AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

6. CHAMP Densities Eight Focus Areas • Scales of Density Variability, Winds, and Drag Prediction: • What spatial and temporal • scales of drag variability • are most relevant to in- • track error? • Internal Processes and • Thermosphere-Ionosphere • Coupling: How do cooling processes regulate the response and recovery of magnetic storms? What is the impact of T-I coupling on the neutral density structure? What is the source of the semiannual variation and its solar cycle dependence? AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

7. (Geoff Crowley - Numerical Experiments Using TIMEGCM Model) -- Joule Heating -- Density • 4 hr delay Eight Focus Areas • Energy Partitioning at High Latitudes and Density Implications • How is magnetospheric • energy input partitioned • (Joule heating, momentum • transfer, etc.) and what • are the implications for • density and density-driver • -relationships? • IV. Wave Forcing from the Lower Atmosphere • What are the meteorological influences on thermosphere density, and can a predictive capability be developed? AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

8. Eight Focus Areas • Forecasting • Geomagnetic Activity • Objective: Use observations in the • photosphere, corona, at L1 and • numerical models of the heliosphere and magnetosphere to: • Improve existing empirical and numerical models of the heliosphere and geospace; and • Achieve more realistic short-term and • probabilistic long-term forecasting. • Forecasting Solar EUV/UV Radiation • Objective: Develop EUV & UV solar flux forecasts • up to a few weeks using: • near-side solar observations and • far-side helio-seismological and L-scattering observations AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

9. Eight Focus Areas • Driver-Response • Relationships • What are the dominant modes • of density variability, and how • do they relate to the drivers? • VIII. Satellite Drag in the Transition Region Utilize Direct Simulation Monte Carlo (DSMC) methods to simulate and understand drag coefficient changes In the re-entry regime (ca. 150-90 km). Use tidal theory, wind and temperature Observations to model density variability in the re-entry regime. AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

10. Research Highlight:Rotating Solar Coronal Holes and Periodic Modulation of the Upper Atmosphere Lei, J., Thayer, J.P., Forbes, J.M., Sutton, E.K., and R.S. Nerem, Rotating Solar Coronal Holes and Periodic Modulation of the Upper Atmosphere, Geophys. Res. Lett., in press, 2008. Thayer, J.P., Lei, J., Forbes, J.M., Sutton, E.K., and R.S. Nerem, Thermospheric Density Oscillations due to Periodic Solar Wind Fast Streams, J. Geophys. Res., in press, 2008. Lei, J., Thayer, J.P., Forbes, J.M., Sutton, E.K.,Nerem, R.S., Temmer, M., and A.M. Veronig, Periodic oscillations in thermospheric density measured by theCHAMP satellite during the declining phase of solar cycle 23, J. Geophys. Res., submitted, 2008. AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

11. During declining and low solar activity, multiple rotating coronal holes produce periodic high-speed solar wind streams. At Earth, these high-speed streams modulate geomagnetic activity in the geospace environment with the same periodicity. AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

12. Thermosphere Density - 400 km F10.7 Solar Wind Speed Kp AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

13. TIMED/SEE Spectra for all of 2005 A triad of coronal holes during 2005 leads to a 27d/3 = 9d periodicity in thermosphere density Thermosphere Density - 400 km F10.7 Solar Wind Speed Kp AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

14. Latitude Structure of Density Response A: Actual Data B: Band-Pass Filtered Data Density at 400 km Percent density change An element of predictability is inherent in this phenomenon! AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

15. Thermosphere Density - 400 km Thermosphere Density - 400 km 27d/2 = 13.5 F10.7 27d/4 = 6.8 Solar Wind Speed 27d/3 = 9.0 27d Kp AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

16. google: ‘asen-5335’ AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

17. Additional Slides More Details of Focus Areas AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

18. CHAMP Densities Focus Area I: Scales of Density Variability, Winds, and Drag Prediction Forbes, Born, McLaughlin, Thayer, Fuller-Rowell • Objectives • Gain quantitative knowledge and a deeper • understanding of how prediction error • depends on the various facets of density • variability. • Connect our scientific research activities • to the actual prediction of satellite • ephemerides. Sample Question: What spatial and temporal scales of drag variability are most relevant to in-track error? Methodology: A test bed of satellites will be used to perform satellite orbit predictions, and to evaluate predicted versus actual in-track satellite positions (“in-track errors”) in terms of characteristics of density variability (e.g., scale size). Anticipated Outcome: Understand what spatial and temporal resolutions that both empirical and first-principles models should seek to achieve, as well as the required temporal resolution of geophysical indices or data that drive the models. AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

19. Focus Area II: Internal Processes and Thermosphere-Ionosphere Coupling Fuller-Rowell, Forbes, Thayer, Codrescu, Crowley, Solomon, Richmond Relationship between  and Ne - from CHAMP Objective: Attain improved understanding of internal processes, and capture this understanding in the next generation of hybrid empirical/physical models. Sample Questions: • What is the impact of T-I coupling on the neutral density structure? • What is the source of the semiannual variation and its solar cycle dependence? • How do cooling processes regulate the response and recovery of magnetic storms? AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

20. 12 18 06 00 Focus Area III: Energy Partitioning at High Latitudes and Density Implications Thayer, Fuller-Rowell, Codrescu, Crowley, Knipp, Forbes, Richmond • Objectives • Improve scientific understanding of the high latitude energy input; energy partitioning into other forms; neutral density and wind responses to these high latitude energy inputs. • Develop driver-response relationships to improve empirical model specifications. Sample Question: In what ways are the solar flux, kinetic energy flux and Poynting flux related? Methodology: Numerical experiments to evaluate solar flux production of electron density and the concomitant change in the Joule heating rate; assess impact on global temperatures and density. Perform similar numerical experiments using empirical relations with kinetic energy flux and Poynting flux. Anticipated Outcome: Understand the correlations amongst the fluxes to develop driver-response relationships that may depend on multiple energy sources . AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

21. Focus Area IV: Wave Forcing from the Lower Atmosphere Akmaev, Forbes, Fuller-Rowell • Objectives • Delineate density variations at planetary-wave (PW) periods (2-20 days) and understand their origin. • Develop driver - response relationships to enable predictive capability. Sample questions • What are the observed characteristics? • How are they connected to dynamical variations in the strato-mesosphere? • Can PW-period density variations be empirically accounted for in models such as J70 and JB2006? • Can PW periodicities in density be reliably predicted with whole-atmosphere models on time scales of ~one to two weeks in advance? AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

22. Focus Area V: Forecasting Geomagnetic ActivityOdstrcil, Pizzo, Falconer, Raeder, Fuller-Rowell Objectives: Improve existing empirical and numerical models of the heliosphere and geospace to achieve more realistic short-term and probabilistic long-term forecasting. • Methodology: Use observations in the photosphere (left-top), corona (left-bottom), at L1 (bottom-center), and numerical models of the heliosphere (top-center) and magnetosphere (right). • Anticipated Outcome: Improved forecasting ability with the lead times: • 30-60 min: driving magnetospheric models by L1 observations; • 1-3 days: driving heliospheric models by coronal observations; • 3-5 days: using probability of solar magnetic eruptions. AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

23. Objective • Develop forecasts of EUV and UV solar flux variability up to a few weeks in advance. Focus Area VI: Forecasting Solar EUV/UV RadiationFontenla, Woods, Avrett, Quemaris, Lindsey • Methodology • Using various measurements of solar properties on the near-side (Earth-facing) part of the Sun, models of the solar atmosphere, and existing empirical relationships, construct solar spectra or “masks” • for 10 positions on the • solar disk each day. • Validate against SORCE • and other measurements. • Use helio-seismological and L scattering observations of the far-side of the Sun to apply corrections to the “obsolete”parts of the mask. (Active regions change since the last time they were seen on the near-side) AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

24. AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

25. 145 km 100 km Focus Area VIII: Satellite Drag in the Re-Entry Region: Satellite Drag Brian Argrow and Jeff Forbes • Motivation • Accurate CDessential for drag prediction • DSMC can be applied for transition flow regime • Gas surface interaction models are the source of most error for current CDcomputations DSMC Simulations of a Hypersonic Waverider at 100 km and 145 km (density contours) Methodology: Application of the Direct Simulation Monte Carlo (DSMC) for vehicle simulations from free-molecular flow to slip-flow regimes with emphasis on the gas-surface interaction model. Anticipated Outcome: Data base of altitude-dependent CDvalues for representative satellite geometries. Simulate aerodynamic forces for trajectory analysis AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008

26. Reconstructed Density Diurnal Amplitudes 110 km, September 2005 Focus Area VIII: Satellite Drag in the Re-Entry Region: Tidal and Longitude Variations in Density Jeff Forbes and Jens Oberheide • Motivation • Re-entry prediction an important • problem. • Few density measurements exist at re- • entry altitudes (ca. 80-200 km) • Strong longitude variations in tides • known to exist in temperature and wind • measurements Methodology: A fitting scheme using “Hough Mode Extensions” will be applied to TIMED/SABER and TIMED/TIDI measurements of temperatures and winds over 80-120 km and -50o to +50o latitude during 2002-2006. Anticipated Outcome: global specifications of longitude-dependent tidal variations in density, winds, and temperature over the 80-200 km height region. AFOSR MURI: Neutral Atmosphere Interdisciplinary Research (NADIR) • Space Weather Workshop, 2008