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Interhemispheric Studies Through AON and PAntOS Vladimir Papitashvili Department of Atmospheric, Oceanic and Space Sciences University of Michigan IPY.

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Presentation on theme: "Interhemispheric Studies Through AON and PAntOS Vladimir Papitashvili Department of Atmospheric, Oceanic and Space Sciences University of Michigan IPY."— Presentation transcript:

1 Interhemispheric Studies Through AON and PAntOS Vladimir Papitashvili Department of Atmospheric, Oceanic and Space Sciences University of Michigan IPY Cluster Project #63 Heliosphere Impact on Geospace Kick-off Workshop, Finnish Meteorological Institute Helsinki, Finland, 5-9 February 2007

2 GEOSPACE: Solar Wind and Earth’s Magnetosphere Courtesy of NASA

3 Solar Wind and Interplanetary Magnetic Field, Earth’s Magnetosphere, Plasmasphere, and Ionosphere Complex, Coupled System with the Mass & Energy Transfer Magnetic conjugacy studies are of general interest because of their implications concerning the processes that electrically couple the magnetosphere and ionosphere. … Four major categorizations seem to occur : 1.clearly conjugate features implying similar topologies and precipitation patterns; 2.conjugate features implying similar topologies, but with distinct differences in precipitation characteristics; 3.features that occur in both hemispheres but at different MLT; and 4.features that appear in only one hemisphere. J. S. Murphree and J. D. Craven “Evaluation of the High Latitude Magnetic Conjugacy of Auroral Features Based on DE-1 and Viking Data”, AGU Fall Meeting 2001, Abstract #SM32A-0808.

4 Could Earth’s Polar Regions be Windows to Geospace and to Heliosphere? What spacecraft can see from geospace? Jupiter’s Polar Regions

5 Substorm’s Onset and Theta Aurora in Opposite Hemispheres: September 18, 2000 Northern Hemisphere 10-12 MLT 74-80 degrees No Theta Aurora Southern Hemisphere 11-15 MLT 80-87 degrees Theta Aurora Østgaard et al., GRL, 2003

6 Substorm Onset in Conjugate Hemispheres IMAGE Spacecraft Far Ultra Violet Camera & Wide Imaging Camera What controls asymmetry of substorm onset locations? POLAR Spacecraft Visible Imaging System Earth camera Courtesy of Nikolai Østgaard

7 All-sky TV data (23:19:30 - 23:23:50 UT, 10 sec interval) September 26, 2003 over Tjornes (Iceland) and Syowa (Antarctica) Exceptionally synchronous discrete auroras over Tjornes (Iceland) and Syowa (Antarctica) Sato et al., GRL, 2005 What controls the size, shape, and location of conjugate auroral forms?

8 Polar Caps and Auroral Ovals in Corrected Geomagnetic Coordinates http://modelweb.gsfc.nasa.gov/models/cgm/ NorthSouth with magnetospheric sources added (solid lines) (dashed lines)

9 WinterSummerIMF B T = 5 nT IMF-Dependent Maps of Ground Magnetic Field Perturbations

10 Papitashvili, V. O., and F. J. Rich, High-latitude ionospheric convection models derived from Defense Meteorological Satellite Program ion drift observations and parameterized by the interplanetary magnetic field strength and direction, J. Geophys. Res., 107, No. A8, 10.1029/2001JA000264, SIA 17(1-13), 2002. DMSP-based IMF-Dependent Maps of Ionospheric Plasma Convection http://mist.engin.umich.edu/ Northern SummerSouthern WinterIMF B T = 5 nT

11 IMF-Dependent Maps of Field-Aligned Currents http://mist.engin.umich.edu Papitashvili, V. O., F. Christiansen, and T. Neubert, A new model of field-aligned currents derived from high- precision satellite magnetic field data, Geophys. Res. Lett., 29, No. 14, 10.1029/2001GL014207, 2002. Northern WinterIMF = 5 nTSouthern Summer

12 DMSP-based Cross-Polar Cap Potential Ratio IMF ~ 0 IMF South N. Summer / S. Winter 0.94 0.64 S. Summer / N. Winter 0.83 0.88 N. Equinox / S. Equinox 0.89 0.90 Cross-polar cap potential drop in the sunlit polar cap is ~15% lower than in the dark cap Ørsted-based S. Summer S. Equinox Field-Aligned --------------- --------------- Currents Ratio N. Winter N. Equinox Dayside 1.8 1.0 Dawn R1/R2 1.5 1.0 Dusk R1/R2 1.5 1.0 Nightside 1.0 1.0 R1/R2 field-aligned currents are 1.5 times stronger when they flow in sunlit polar cap Magnetosphere-Ionosphere Voltage-Current Relation Experiment and Theory Siscoe et al., JGR, 2002:  pc (kV) = 101  21.8 J R1 (MA) If J R1winter = 1.0 MA & J R1summer = 1.5 MA, then  sum /  win = (101  33)/(101  22) = 68 / 81 = 0.84

13 MHD-modelled Ionospheric Electrodynamics for the Northern Polar Cap Ionospheric potentials Ridley, A. J., The effects of seasonal changes in the ionospheric conductances on magnetospheric field-aligned currents, submitted to Geophys. Res. Letters, October 2006. Spring Summer Fall Winter Pedersen conductance Field-aligned currents

14 MHD-modelled Ionospheric Electrodynamics for the Northern Polar Cap Cross-polar cap potential Winter Spring Summer Fall Winter Maximum of derived field-aligned currents Ridley, A. J., The effects of seasonal changes in the ionospheric conductances on magnetospheric field-aligned currents, submitted to Geophys. Res. Letters, October 2006. Equinox-Summer = 72 kV Winter = 83 kV ~15% Summer = 0.47  A/m 2 Equinox-Winter = 0.30  A/m 2 ~1.6 times stronger

15 Mapping Magnetopause Reconnection to Conjugate Polar Caps Northern Winter Solstice for 05 UT Coleman, I. J., M. Pinnock, and A. S. Rodger, The ionospheric footprint of antiparallel merging regions on the dayside magnetopause, Annales Geophysicae, 18, 511-516, 2000. Northern Summer Solstice for 17 UT  Note summer merging lines are shorter in length than winter ones  Difference in the merging lines length could be a geometrical effect due to the Earth’s dipole tilt  However, this could be the effect predicted from our sketch for the Hill’s voltage-current relationship

16 Geomagnetic Conjugacy Greenland West Coast and Eastern Antarctic P5 P3 P4 VOS Greenland West Coast Magnetometer Chain ~40  CGM meridian (12 stations) Eastern Antarctic Magnetometer Sites ~40  CGM meridian (6 stations) 65  75  85   60  7070 8080          BAS LPMs A81   P2 SPA P6 P1

17 SuperDARN Radars and Magnetometers in the Arctic and Antarctic ExistingPlanned NIPR LPM between Syowa & Dome F U. Michigan LPM test run at South Pole Syowa

18 Mission Science Objectives Primary What macroscale instability causes substorm onset? Secondary How are radiation belt (killer) electrons energized? Tertiary Dayside solar wind - magnetosphere coupling processes THEMIS = Time History of Events and Macroscale Interactions in Substorms NASA Launch – February 15, 2007

19 THEMIS – From Geospace to Ground 20 All-Sky Cameras Deployed Across Alaska and Canada

20 Onset location and timing relative to boundaries etc. Magnetosphere - Ionosphere coupling in substorms Auroral signatures of magnetospheric dynamics And on and on… THEMIS and Interhemispheric Conjugacy Studies

21

22 COMMITTEE ON DESIGNING AN ARCTIC OBSERVING NETWORK W. Berry Lyons (Chair), The Ohio State University, Columbus Keith Alverson, Global Ocean Observing System Project Office, IOC/UNESCO, Paris David Barber, Univ. of Manitoba, Winnipeg James G. Bellingham, Monterey Bay Aquarium Research Institute, California Terry V. Callaghan, University of Sheffield, UK & Abisko Sci. Res. Station, Sweden Lee W. Cooper, University of Tennessee Margo Edwards, University of Hawaii Shari Gearheard, Univ. of Western Ontario Molly McCammon, Alaska Ocean Observing System, Anchorage Jamie Morison, Polar Science Center, Seattle Scott E. Palo, University of Colorado, Boulder Andrey Proshutinsky, Woods Hole Oceano- graphic Institution, Massachusetts Lars-Otto Reiersen, Arctic Monitoring and Assessment Programme, Oslo, Norway Vladimir E. Romanovsky, Univ. of Alaska Peter Schlosser, Lamont-Doherty Earth Observatory, Palisades, New York Julienne C. Stroeve, National Snow and Ice Data Center, Boulder, Colorado Craig Tweedie, University of Texas, El Paso John Walsh, University of Alaska, Fairbanks Out of 18 members, only Scott E. Palo, University of Colorado represented STP & Aeronomy

23 Summary Observable changes, many of which have regional and global implications, are underway across the Arctic. Although the Arctic is not the only region on Earth affected by environmental change, it … is a region with a limited record of observations … and yet, despite these constraints, rapid and systemic changes have clearly been identified. The interconnectedness of physical, biological, chemical, and human components, together with the high amplitude of projected changes, make a compelling argument for an improved observation infrastructure that delivers a coherent set of pan-arctic, long-term, multidisciplinary observations. Without such observations, it is very difficult to describe current conditions in the Arctic, let alone understand the changes that are underway or their connections to the rest of the Earth system. Without such observations, society’s responses to these ongoing changes and its capability to anticipate, predict, and respond to future changes that affect physical processes, ecosystems, and arctic and global residents are limited. This report outlines the potential scope, composition, and implementation strategy for an Arctic Observing Network (AON). Such a network would build on and enhance existing national and international efforts and deliver easily accessible, complete, reliable, timely, long-term, pan-arctic observations. The goal is a system that can detect conditions and fundamental variations in the arctic system, provide data that are easily compared and analyzed, and help improve understanding of how the arctic system functions and changes. The network would serve both scientific and operational needs.

24 Evolution of the Arctic Observing Network

25 Pan-Antarctic Observations System (PAntOS)


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