ESS 261Multi-Instrument/Spacecraft 1 Multi-instrument, multi-spacecraft analysis … Finite Gyroradius (from last time) Review: SST cleanup, MHD Electric Field from Particle Velocity Total Density Computation from Various Sources Total Pressure ESS 261 Spring Quarter 2009 Lecture 05 May 27, 2009

ESS 261Multi-Instrument/Spacecraft 2 Finite gyroradius techniques Ion Gyroradius large compared to magnetospheric boundaries –Can be used to remotely sense speed and thickness of boundaries –Assumption is that boundary is sharp and flux has step function across Application at the magnetopause Application at the magnetotail –Can also be applied to waves if particle gradient is sufficiently high Application on ULF waves at inner magnetosphere Method exploits finite ion gyroradius to remotely sense approaching ion boundary and measure boundary speed (V ⊥ ) THEMIS To Earth To Sun To Tail

ESS 261Multi-Instrument/Spacecraft 3 At the magnetotail  i,thermal-tail (4keV,20nT) =~325km  i,super-thermal (50keV,20nT) =~2200km Plasma Sheet Thickness ~ 1-3 R E Boundary Layer Thickness ~ km Current layer Thickness~ km Waves Across Boundary: ~ ,000km Along Boundary: ~Normal : 1-10 R E For magnetotail particles, the current layer and plasma sheet boundary layer are sharp compared to the superthermal ion gyroradius and the magnetic field is the same direction in the plasma sheet and outside (the lobe). This means we can use the measured field to determine gyrocenters both at the outer plasma sheet and the lobe, on either side of the hot magnetotail boundary.

ESS 261Multi-Instrument/Spacecraft 4 Side View (elevations) To Sun Spin Axis ESA: Elevation direction (  DSL ) SST: Elevation direction (  DSL ) 25 o 52 o -25 o -52 o o o

ESS 261Multi-Instrument/Spacecraft 5 Top View (sectors) For ESA and SST (0=Sun) Spin motion direction (  DSL ) o o To Sun (0 o ) Spin axis Normal to Sun, +90 o

ESS 261Multi-Instrument/Spacecraft 6 Particle motion direction Coordinate: (  DSL ) Energy: keV Note: direction depends on spin axis. B field azimuth (solid white) -B field azimuth (dashed white) You care to time this! (+/- 90 o to Bfield azimuth)

ESS 261Multi-Instrument/Spacecraft 7 Multiple spacecraft, energies, elevations A B D E …. Elev: 25deg E=30-50keVElev: 25deg, E=80-120keV

ESS 261Multi-Instrument/Spacecraft 8 Vi_const 310km/sec/keV fci_cons Hz/nT B 30nT Ti 40keV rho_ion 683km Ti 100keV rho_ion 1081km Ti 150keV rho_ion 1323km Ti 300keV rho_ion 1872km SC E (keV) detectord (deg) r time B 40 SPW :19:29 B 40 SPE :19:39 B 40 SEW :19:18 B 40 SEE :19:42 B 40 NPW :19:29 B 40 NPE :19:38 B 40 NEW :19:24 B 40 NEE :19:43 B 100 SPW :19:17 B 100 SPE :19:42 B 100 SEW :19:20 B 100 SEE :19:45 B 100 NPW :19:20 B 100 NPE :19:45 B 100 NEW :19:23 B 100 NEE :19:48 B 150 SPW :19:10 B 150 SPE :19:44 B 150 SEW :19:14 B 150 SEE :19:51 B 150 NPW :19:23 B 150 NPE :19:45 B 150 NEW :19:13 B 150 NEE :19:48 B 300 SPW :19:10 B 300 SPE :19:44 B 300 SEW :19:14 B 300 SEE :19:51 B 300 NPW :19:23 B 300 NPE :19:45 B 300 NEW :19:13 B 300 NEE :19:48 Note: NEE= North-Equatorial, East NPW=North-Equatorial, West Angles measured from East direction -25deg elevation, 90deg East = SEE +52deg elevation, 90deg East = NPE … Spin axis B NPW NEW SEW SPW NPE NEE SEE SPE Boundary

ESS 261Multi-Instrument/Spacecraft 9 Spin axis B NPW NEW SEW SPW NPE NEE SEE SPE Boundary V: NEE Part. direction Hot/dense plasma Cold/tenuous plasma Y Z GC NEE n Y   Y n Show: d=  *sin(  -  ) Note: d negative if moving towards spacecraft  d SC

ESS 261Multi-Instrument/Spacecraft 10 Procedure –For a given , determine variance of data for all  –Find minimum in variance, this determines  (boundary direction) –Speed distance as function of time determines boundary speed –intro_ascii,'remote_sense_A.txt',delta,rho,hh,mm,ss,nskip=13,format="(25x,f6.1,f8.1,3(1x,i2))" –; –angle=fltarr(73) –chisqrd=fltarr(73) –for ijk=0,72 do begin – epsilon=float(ijk*5) – get_d_vs_dt,epsilon,hh,mm,ss,rho,delta,dist,times – yfit=dist & yfit(*)=0. – chi2=dist & chi2(*)=0. – coeffs=svdfit(times,dist,2,yfit=yfit,chisq=chi2) – angle(ijk)=epsilon – chisqrd(ijk)=chi2 –endfor –ipos=indgen(30)+43 –chisqrd_min=min(chisqrd(ipos),imin) –plot,angle,chisqrd –print,angle(ipos(imin)),chisqrd(ipos(imin)) –; –stop

ESS 261Multi-Instrument/Spacecraft km V ~ 70km/s Z Y D B A Procedure –Note two minima (identical solutions) One for approaching boundary at V>0 One for receding boundary at V<0 –Convention that d<0 if boundary moves towards spacecraft allows us to pick one of the two (positive slope of d versus time)

ESS 261Multi-Instrument/Spacecraft 12 t cross V [km/s]  [deg] D 11:19: B11:19: A11:19: Table 1. Results of remote sensing analysis on the inner probes Timing of the arrivals of the other signatures at the inner three spacecraft

ESS 261Multi-Instrument/Spacecraft 13 At the magnetopause  i,sheath (0.5keV,10nT) =~200km  i,m-sphere (10keV,10nT) =~1000km Magnetopause Thickness ~ 6000km Current layer Thickness~ 500km FTE scale, Normal 2 Boundary: ~6000km Along Boundary: ~Normal : 1-3 R E For leaking magnetospheric particles, the current layer is sharp compared to the ion gyroradius and the magnetic field is the same direction in the sheath and the magnetopause outside the current layer. This means we can use the measured field outside the magnetopause to determine gyrocenters both at the magnetopause and the magnetosheath on either side of the hot magnetopause boundary.

ESS 261Multi-Instrument/Spacecraft 14 Magnetopause encounter on July 12, 2007 Magnetic field angle is 60deg below spin plane and +120deg in azimuth i.e., anti-Sunward and roughly tangent to the magnetopause. The particle velocities, centered at 52deg above the spin plane, have roughly 90 o pitch angles, with gyro-centers that were on the Earthward side of the spacecraft. The energy spectra of the NP particles show clearly the arrival of the FTE ahead of its magnetic signature, remotely sensing its arrival due to the finite gyroradius effect of the energetic particles.  T=55s,   i,100keV, 28nT) =1150km, V=40km/s

ESS 261Multi-Instrument/Spacecraft 15 At the near-Earth magnetosphere

ESS 261Multi-Instrument/Spacecraft 16 At the near-Earth magnetosphere

ESS 261Multi-Instrument/Spacecraft 17 At the near-Earth magnetosphere timespan,' /10',2,/hours & sc='a' thm_load_state,probe=sc,/get_supp thm_load_fit,probe=sc,data='fgs',coord='gsm',suff='_gsm' thm_load_mom,probe=sc ; L2: onboard processed moms thm_load_esa,probe=sc ; L2: gmoms, omni spectra tplot,'tha_fgs_gsm tha_pxxm_pot tha_pe?m_density tha_pe?r_en_eflux' ; trange=[' /11:00',' /11:30'] thm_part_getspec, probe=['a'], trange=trange, angle='gyro', $ pitch=[45,135], other_dim='mPhism', $ ; /normalize, $ data_type=['peir'], regrid=[32,16] tplot,'tha_peir_an_eflux_gyro tha_fgs_gsm tha_pxxm_pot tha_pe?m_density tha_pe?r_en_eflux' Remote sensing of waves in ESA data, at the most appropriate coordinate System, I.e, field aligned coordinates. gyro=0 o => Earthward particles

ESS 261Multi-Instrument/Spacecraft 18 At the near-Earth magnetosphere trange=[' /11:00',' /11:30'] thm_part_getspec, probe=['a'], trange=trange, angle='gyro', $ pitch=[45,135], other_dim='mPhism', $ /normalize, $ data_type=['peir'], regrid=[32,16] tplot,'tha_peir_an_eflux_gyro tha_fgs_gsm tha_pxxm_pot tha_pe?m_density tha_pe?r_en_eflux' Same as before but using keyword: /normalize I.e., anisotropy is normalized to 1, to ensure flux variations do not affect anisotropy calculation.

ESS 261Multi-Instrument/Spacecraft 19 Clean up SST, ESA, EFI measurements [1] Preliminary Tasks –SST: Sun contamination removal (see Lecture 08) –ESA: background noise removal (mostly in tail, inner magnetosphere) –ESA: watch-out for cold ions (via total density, spectra, mostly dayside) –EFI: remove offsets, watch-out for cold ion wake (via waveforms) –Obtain partial moments, add them, compare with scpot-density –Ready for further analysis

ESS 261Multi-Instrument/Spacecraft 20

ESS 261Multi-Instrument/Spacecraft 21

ESS 261Multi-Instrument/Spacecraft 22 Preliminary Tasks [clean SST] –timespan,' /03',3,/hours –sdate=time_double(' /03:00:00') –edate=time_double(' /06:00:00') –trange=[sdate,edate] –; –eVpercc_to_nPa=0.1602/1000. ; multiply –nTesla2_to_nPa=0.01/ ; multiply –; –thm_load_state,/get_supp –thm_load_fgm,probe='e',coord='dsl gsm' –thm_load_sst,probe='e' ; reads L1 SST data –thm_load_esa,probe='e' ; reads L2 ESA data –; –; Clean up SST data –sc='e' –thm_part_getspec, probe=sc,trange=trange, $ – theta=[-45,0],data_type=['psif','psef'],angle=phi,suff='_m45'$ –, erange=[25000,100000] –thm_part_getspec, probe=sc,trange=trange, $ – theta=[-90,0],data_type=['psif','psef'],angle=phi,suff='_m90'$ –, erange=[25000,100000] –thm_part_getspec, probe=sc,trange=trange, $ – theta=[0,45],data_type=['psif','psef'],angle=phi,suff='_p45'$ –, erange=[25000,100000] –thm_part_getspec, probe=sc,trange=trange, $ – theta=[45,90],data_type=['psif','psef'],angle=phi,suff='_p90'$ –, erange=[25000,100000] –example of plotting spectra as lines –options,'th'+sc+'_ps?f_an_eflux_phi*',spec=0 ; line plot: spec=0, spectra: spec=1 –ylim,'th'+sc+'_ps?f_an_eflux_phi*',1.e-5,1.e-5,1 –tplot_options,'th'+sc+'_ps?f_an_eflux_phi*',title='Line plot' –tplot,'th'+sc+'_ps?f_an_eflux_phi*' –; –; replot as spectra –options,'th'+sc+'_ps?f_an_eflux_phi*',spec=1 ; line plot: spec=0, spectra: spec=1 –tplot_options,'th'+sc+'_ps?f_an_eflux_phi*',title=' ' –ylim,'th'+sc+'_ps?f_an_eflux_phi*',0,360,0 –tplot,'th'+sc+'_psif_an_eflux_phi* th'+sc+'_psef_an_eflux_phi*' –tplot,/pick

ESS 261Multi-Instrument/Spacecraft 23 Preliminary Tasks [clean SST #2] –; SST Ions only enough, no need for electrons now –; –edit3dbins,thm_sst_psif(probe=sc, gettime(/c)), ibins –print,ibins –tplot,'th'+sc+'_psif_an_eflux_phi* th'+sc+'_psef_an_eflux_phi*' –t1=time_double(' /03:15:00') –t2=time_double(' /03:18:00') –times=[t1,t2] –; –thm_part_getspec, probe=sc,$ – theta=[-45,0],data_type=['psif'],angle=phi,suff='_m45c'$ –, erange=[25000,100000],/mask_remove,fillin_method='interpolation'$ –, method_sunpulse_clean='median' $ –, enoise_bins=ibins, enoise_bgnd_time=times –thm_part_getspec, probe=sc,$ – theta=[-90,0],data_type=['psif'],angle=phi,suff='_m90c'$ –, erange=[25000,100000],/mask_remove,fillin_method='interpolation'$ –, method_sunpulse_clean='median' $ –, enoise_bins=ibins, enoise_bgnd_time=times –thm_part_getspec, probe=sc,$ – theta=[0,45],data_type=['psif'],angle=phi,suff='_p45c'$ –, erange=[25000,100000],/mask_remove,fillin_method='interpolation'$ –, method_sunpulse_clean='median' $ –, enoise_bins=ibins, enoise_bgnd_time=times –thm_part_getspec, probe=sc,$ – theta=[45,90],data_type=['psif'],angle=phi,suff='_p90c'$ –, erange=[25000,100000],/mask_remove,fillin_method='interpolation'$ –, method_sunpulse_clean='median' $ –, enoise_bins=ibins, enoise_bgnd_time=times –thm_part_moments,probe=probe,instrum=['psif'] $ –,/mask_remove,fillin_method='interpolation'$ –, method_sunpulse_clean='median' $ –, enoise_bins=ibins, enoise_bgnd_time=times $ –, /scale_sphere –thm_part_getspec, probe=sc $ –, data_type=['psif'],/energy $ –,/mask_remove,fillin_method='interpolation' $ –, method_sunpulse_clean='median' $ –, enoise_bins=ibins, enoise_bgnd_time=times $ –ylim,'th'+sc+'_psif_density',1.e-5,1.e-5,1 –ylim,'th'+sc+'_psif_velocity',0,0,0 –ylim,'th'+sc+'_psif_t3',1.e-5,1.e-5,1 –; –tplot,'the_psif_density the_psif_velocity the_psif_t3 the_psif_en_eflux th'+sc+'_psif_an_eflux_phi_???c'

ESS 261Multi-Instrument/Spacecraft 24

ESS 261Multi-Instrument/Spacecraft 25 Recompute ESA moments, using reworked sc_pot –tplot,'the_pxxm_pot',/add –get_data,'the_pxxm_pot',data=the_pxxm_pot –the_pxxm_pot.y=(the_pxxm_pot.y+1.)*1.15 ; correct for sphere bias and shielding –store_data,'the_pxxm_pot1',data={x:the_pxxm_pot.x,y:the_pxxm_pot.y} –thm_load_esa_pkt,probe='e' –thm_part_moments,probe=sc,instrum=['peir', 'peer'],scpot_suffix='_pxxm_pot1',tplotsuffix='_norm',trange=[sdate,edate] –; –; recompute total density, velocity, temperature –sst_scale=1. –; –; density –; –tinterpol_mxn,'the_psif_density','the_peir_density_norm',suff='_int' –calc,'"the_psif_density_int" = sst_scale*"the_psif_density_int"' –add_data,'the_psif_density_int','the_peir_density_norm',newname='the_ptim_density_new' –;

ESS 261Multi-Instrument/Spacecraft 26 Recompute ESA mom’s, using reworked sc_pot [2] –; –; velocity –; –tinterpol_mxn,'the_psif_velocity','the_peir_density_norm',suff='_int' –get_data,'the_psif_density_int',data=the_psif_density_int –get_data,'the_psif_velocity_int',data=the_psif_velocity_int –get_data,'the_peir_density_norm',data=the_peir_density_norm –get_data,'the_peir_velocity_norm',data=the_peir_velocity_norm –get_data,'the_ptim_density_new',data=the_ptim_density_new –vel_tot_0=(the_psif_density_int.y*the_psif_velocity_int.y(*,0)+ $ – the_peir_density_norm.y*the_peir_velocity_norm.y(*,0) ) / $ – the_ptim_density_new.y –vel_tot_1=(the_psif_density_int.y*the_psif_velocity_int.y(*,1)+ $ – the_peir_density_norm.y*the_peir_velocity_norm.y(*,1) ) / $ – the_ptim_density_new.y –vel_tot_2=(the_psif_density_int.y*the_psif_velocity_int.y(*,2)+ $ – the_peir_density_norm.y*the_peir_velocity_norm.y(*,2) ) / $ – the_ptim_density_new.y –store_data,'the_ptim_velocity_new',data={x:the_peir_density_norm.x, $ – y:[[vel_tot_0],[vel_tot_1],[vel_tot_2]]} –options,'the_ptim_velocity_new',colors=[2,4,6] –;

ESS 261Multi-Instrument/Spacecraft 27 Recompute ESA mom’s, using reworked sc_pot [3] –; pressure and temperature –; –tinterpol_mxn,'the_psif_t3','the_peir_density_norm',suff='_int' –get_data,'the_psif_t3_int',data=the_psif_t3_int –get_data,'the_peir_t3_norm',data=the_peir_t3_norm –get_data,'the_peer_t3_norm',data=the_peer_t3_norm –press_tot=the_psif_density_int.y*total(the_psif_t3_int.y,2)/3 + $ – the_peir_density_norm.y*total(the_peir_t3_norm.y,2)/3 –store_data,'the_ptim_pressure_new',data={x:the_peir_density_norm.x, $ – y:press_tot} –store_data,'the_psif_pressure_int',data={x:the_peir_density_norm.x, $ – y:the_psif_density_int.y*total(the_psif_t3_int.y,2)/3} –store_data,'the_peir_pressure_norm',data={x:the_peir_density_norm.x, $ – y:the_peir_density_norm.y*total(the_peir_t3_norm.y,2)/3} –div_data,'the_ptim_pressure_new','the_ptim_density_new',newname='the_ptim_temperature_new' –store_data,'the_peer_pressure_norm',data={x:the_peir_density_norm.x, $ – y:the_peir_density_norm.y*total(the_peer_t3_norm.y,2)/3} –;

ESS 261Multi-Instrument/Spacecraft 28 Recompute ESA mom’s, using reworked sc_pot [4] –; –; Plot 'em –; –store_data,'the_N_combo',data='the_psif_density_int the_peir_density_norm the_ptim_density_new' –store_data,'the_P_combo',data='the_psif_pressure_int the_peir_pressure_norm the_ptim_pressure_new' –ylim,'the_p???_pressure_*',1.e-5,1.e-5,1 –store_data,'the_pxix_en_eflux',data='the_psif_en_eflux the_peir_en_eflux' –ylim,'the_pxix_en_eflux',3.,3.e6,1 –zlim,'the_pxix_en_eflux',50,1.e7,1 –store_data,'the_peer_en_eflux_pot',data='the_peer_en_eflux the_pxxm_pot1' –ylim,'the_peer_en_eflux_pot',5.,3.e4,1 –; –tplot,'the_N_combo the_peir_velocity_norm the_ptim_velocity_new the_P_combo the_pxix_en_eflux the_peer_en_eflux_pot' –;

ESS 261Multi-Instrument/Spacecraft 29

ESS 261Multi-Instrument/Spacecraft 30 Compare E-field with EFI and compute Ptotal –; Introduce B & E field; compute Ez from E*B=0 –; –thm_load_fit,probe=sc,coord='dsl',suff='_dsl' –get_data,'the_efs_0',data=the_efs_0 –i2average=where((the_efs_0.x gt time_double(' /04:45:00')) and $ – the_efs_0.x lt time_double(' /04:48:00'),iany) –print,'this is the estimated Exoffset: ', average(the_efs_0.y(i2average,0)) –print,'this is the estimated Eyoffset: ', average(the_efs_0.y(i2average,1)) –Exoffset= –Eyoffset= –; –angle=10. ; degrees –tanangle=tan(angle*!PI/180.) –get_data,'th'+sc+'_efs_0',data=thx_efs_dsl –get_data,'th'+sc+'_fgs',data=thx_fgs_dsl –igood=where(abs(thx_fgs_dsl.y(*,2)/sqrt(thx_fgs_dsl.y(*,0)^2+thx_fgs_dsl.y(*,1)^2)) ge tanangle,janygood) –ibad=where(abs(thx_fgs_dsl.y(*,2)/sqrt(thx_fgs_dsl.y(*,0)^2+thx_fgs_dsl.y(*,1)^2)) lt tanangle,janybad) –thx_efs_dsl.y(*,0)=thx_efs_dsl.y(*,0)-Exoffset & thx_efs_dsl.y(*,1)=thx_efs_dsl.y(*,1)-Eyoffset –thx_efs_dot0_dsl=thx_efs_dsl –; –if (janybad ge 1) then thx_efs_dot0_dsl.y(ibad,*)=!VALUES.F_NAN –if (janygood lt 1) then print,'*****WARNING: NO GOOD 3D ExB data' –if (janygood ge 1) then thx_efs_dot0_dsl.y(igood,2)= -(thx_efs_dsl.y(igood,0)*thx_fgs_dsl.y(igood,0)+$ – thx_efs_dsl.y(igood,1)*thx_fgs_dsl.y(igood,1)+ thx_efs_dsl.y(igood,2)*thx_fgs_dsl.y(igood,2))/ thx_fgs_dsl.y(igood,2) –; –thx_exb_dot0_dsl=thx_efs_dot0_dsl –store_data,'th'+sc+'_efs_dot0_dsl',data={x:thx_efs_dot0_dsl.x,y:thx_efs_dot0_dsl.y} –options,'th'+sc+'_efs_dot0_dsl','colors',[2,4,6] ;

ESS 261Multi-Instrument/Spacecraft 31 Compare E-field with EFI –; Produce E from Vi x B, to compare –; –tinterpol_mxn,'the_fgs','the_peir_density_norm',suff='_int' ; get same time res. –tcrossp,'th'+sc+'_ptim_velocity_new','th'+sc+'_fgs_int',newname='the_Evxb_dsl_temp' –calc,'"the_Evxb_dsl" = *"the_Evxb_dsl_temp"' –options,'the_Evxb_dsl',colors=[2,4,6] & ylim,'the_Evxb_dsl the_efs_dot0_dsl',-20,20,0 –; –tplot,'the_fgs_int the_Evxb_dsl the_efs_dot0_dsl the_N_combo the_ptim_velocity_new the_P_combo the_pxix_en_eflux the_peer_en_eflux_pot' –; –; Add total ion, electron and magnetic pressure to create total pressure –; –calc,'"the_Pi" = (0.1602/1000.) * "the_ptim_pressure_new"' ; ESA+SST ions in nPa –calc,'"the_Pe" = (0.1602/1000.) * "the_peer_pressure_norm"'; ESA electrons in nPa –tinterpol_mxn,'the_fgs_dsl','the_peir_density_norm',suff='_int' ; on common time –tvectot,'the_fgs_dsl_int',tot='the_fgs_mag' –calc,'"the_Pb" = (0.01/ ) * "the_fgs_mag" * "the_fgs_mag" ' ; Pb in nPa –; –calc,'"the_Pt" = "the_Pi" + "the_Pe" + "the_Pb" ' ; Ptotal in nPa –; –store_data,'the_Pall',data='the_Pi the_Pe the_Pb the_Pt' ; single variable to plot –ylim,'the_P? the_Pall',0.005,1,1 –; –tplot,'the_fgs_int the_Evxb_dsl the_efs_dot0_dsl the_N_combo the_ptim_velocity_new the_P_combo the_Pall the_pxix_en_eflux the_peer_en_eflux_pot' –;

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ESS 261Multi-Instrument/Spacecraft 33 February 16, 2008 event: Moments computation after SST cleanup

ESS 261Multi-Instrument/Spacecraft 34 February 16, 2008 event: ExB comparison