space&plasmas:&from&the&&...
TRANSCRIPT
M.#Velli,##Earth,#Planetary#and#Space#Sciences#UCLA#
Space&Plasmas:&from&the&&Origins&of&the&Heliosphere&to&
Solar&Wind/Magnetosphere&Interac;ons&
UCLA#09/22/2015#
Our&Space&Plasma&Environment&
Sun:%coronal%hea-ng,%Solar%wind,%flares,%CMEs,%shocks,%cosmic%Rays%(SEPs),%CIRs%
Planetary%Magnetospheres:%shocks,%radia-on%belts,%substorms,%storms,%pulsa-ons%%
UCLA#09/22/2015#
Solar&corona,&wind&and&magne;c∾vity&&
UCLA#09/22/2015#4&
The&Solar&Wind&in&3D&
UCLA#09/22/2015#5&
The&Heliosphere&in&4D&
UCLA#09/22/2015#
x
6&
• Sun&–&Earth&plasma&interac;ons:&J&magnetospheric&energy&and∥cle&input&J&foreshock&phenomena&
• Magne;c&to∥cle&energy&conversion&in&the&magnetosphere:&J&reconnec;on&process:&drivers&and&consequences&J&plasma&transport&(convec;on,&turbulence,&driOs)&J∥cle&accelera;on&at&reconnec;on&fronts&&
• Radia;on&belt&dynamics:&J&injec;ons,&wave&growth&&&propaga;on,∥cle&diffusion&
• MagnetosphereJionosphere&coupling:&J&FieldJaligned¤ts,&the&aurora&and&conduc;vity&effects&
• Lunar&exosphere&and&its&plasma&environment:&J&Reflected∥cles,¤tJdriven&instabili;es&
• Projects:&THEMIS,&ARTEMIS,&ELFIN&
Experimental&Space&Physics&V.&Angelopoulos&&
UCLA#09/22/2015#7&
THEMIS (2007) ARTEMIS (2011)
ELFIN (2017)
ELFIN in vibration testing at NASA/Wallops
“Homegrown”&experiments&
UCLA#09/22/2015#8&
dayside
nightside
magnetic reconnection !
Magne;c&reconnec;on:&energy&storage&and&release&in&the&magnetosphere&
UCLA#09/22/2015#9&
Growth
phase arc�
Poleward boundary
intensification�
��
north
70◦�
60◦�
Streamer�
Onset�
N V
THEMIS&has&established&that&reconnec;on&fronts&“drive”&bursty&bulk&flows,&transport&most&of&the&flux&earthward&and&link&nightside&&Rx&to&the&inner&magnetosphere.&
Recent&findings&
The&op;cal&signature&of&this&linkage&are&the&streamers,&emana;ng&from&polar&boundary&intensifica;ons,&propaga;ng&towards&and∾va;ng&the&preJexis;ng&quiet&;me&arc.&
UCLA#09/22/2015#10&
Angelopoulos et al., Science, 2013
An&unprecedented&view&afforded&by&a&“Heliophysics&System&Observatory”#
The&fronts&accelerate&and&heat&ions&and&electrons&bringing&fresh,&anisotropic&popula;ons&to&the&inner&magnetosphere&&
UCLA#09/22/2015#11&
PJJRRGWb
AL
ALABVdBW
E
E
init
initinitL 8.4108.4~
)384(260)2.1(~
2Φ~
2~
215
220
2
0
2
0
223
0
2
=×= ∫ πµµµµ
PJPJWW finL
initL 9.2~9.18.4 −=−
E.g. 7.1 magnitude quake = 2.8PJ “Ivy King”: most powerful pure fission bomb = 2.1PJ
L A
Φ=BA
How&much&energy&is&processed&during&this&(fairly&typical)&substorm?#
UCLA#09/22/2015#
P3:50GW/RE2
P2: 5GW/RE2
JyEy is 2-5 x JyEy,MHD
Reconnection front (Bz>0)
Reconnection front (Bz<0)
20km
150km
Local flux transport at THEMIS (P3) and !
ARTEMIS (P2)
" Energy conversion
Where%does%energy%conversion%take%place?At%the%reconnec6on%fronts:%Most%is%not%in%JEMHD!%(but%due%to%electron%nonCgyrotropy%and%iner-a).%
&
UCLA#09/22/2015#
Numerical&Simula;on&Studies&of&Magnetotail&Reconnec;on&&M.&AshourJAbdalla,&R.&Walker&
&
Mul;scale&approach:&&
# Combine&global&MHD&with&implicit&PIC&model&(iPic3D)&using&a&largeJscale&simula;on&system&(30&RE&x&12&RE&x&12&RE)&
Method:&&
# &&Run&MHD&simula;on&with&upstream&solar&&&&wind&
parameters&
# At&onset&of&tail&reconnec;on&place&3D&iPic3D&&
box&&&(J45&<&x&<&J15,&J3&<&y&<&9,&J9&<&z&<&3)&
ΔPIC#/di#=#0.06###ΔPIC#/de#=#1.0###mi#/me#=#256&
• &Use&ini;al&and&boundary&condi;ons&from&&iPic3D&code&taken&from&MHD&simula;on:&ne#=#ni#=#nMHD### #ve#=#vMHD#+#mi#JMHD#/qe#Ti#=#5Te##=#TMHD# #vi#=#vMHD#+#me#JMHD#/#qi&
• Inject∥cles&with&a&driOing&Maxwellian&based&on&MHD&values.&&Run&simula;on&for&153s.&&&
Y
iPic3D
30 RE 12 RE
12 RE
MHD
UCLA#09/22/2015#
X(RE)
X(RE)
X(RE)
X(RE)
Vix (km/s) Vex (km/s) -2
0
2
4
6
8
X(RE) -15 -20 -25 -30 -35 -40
-45 X(RE)
-2
0
2
4
6
8
-15 -20 -25 -30 -35 -40 -45
Y(R
E)
-2
0
2
4
6
8
X(RE) -15 -20 -25 -30 -35 -40
-45 X(RE)
-2
0
2
4
6
8
-15 -20 -25 -30 -35 -40 -45
Y(R
E)
T = 153 s
T = 115 s
V ex(
km/s
) V e
x(km
/s)
V ix(
km/s
) V i
x(km
/s)
V ex(
km/s
)
Y(R
E)
V ex(
km/s
)
Y(R
E)
Time&Development&of&Vex&and&Vix&&on&&the&Maximum&Pressure&Surface&
UCLA#09/22/2015#
-2 0 2 4 6 8
-2 0 2 4 6 8
Ohm’s Law Perpendicular Slippage
Agyrotropy j ⋅ E
-15 -20 -25 -30 -35 -40 -45 -15 -20 -25 -30 -35 -40 -45
-15 -20 -25 -30 -35 -40 -45 -15 -20 -25 -30 -35 -40 -45
X/RE X/RE
X/RE X/RE
-2 0 2 4 6 8
Y/R
E Y/
RE
-2 0 2 4 6 8
×10-10
Compara;ve&View&of&Measures&of&the&Electron&Diffusion&Region&
UCLA#09/22/2015#16&
# Magnetospheric&Mul;scale&(MMS)&is&a&fourJspacecraO&mission&to&inves;gate&magne;c&reconnec;on&Mission&has&two&phases&–&Phase&1:&Dayside;&Phase&2:&Nightside&
# Main&payload&–&Solving&MagnetoJspheric&Accelera;on,&Reconnec;on&and&Turbulence&(SMART),&PI&J.&Burch&(SwRI)&&
# The&FIELDS&instrument&(PI&R.&Torbert,&UNH)&is&part&of&the&SMART&payload.&FIELDS&includes&fluxgate&(DC)&magneJtometers&with&C.&Russell,&UCLA,&PI&
# Science&team&at&UCLA&includes:&Robert&Strangeway&(Research&Scien;st)&Cong&Zhao&(Grad.&St.)&
Magnetospheric&Mul;&Scale&(MMS)&&C.Russell,&R.&Strangeway&
UCLA#09/22/2015#17&
# Example&to&the&right&shows&mul;ple&magnetopause&crossings&
# Data&were&acquired&on&August&28,&2015&–&plot&shows&~&1&minute&of&data&
# The&MMS&spacecraO&were&in&a&tetrahedron&configura;on&~&160&km&separa;on&
# Even&on&this&scale&the&spacecraO&saw&significantly&different&signatures&&
# Primary&mission&objec;ve&is&capture&magne;c&nulls&and&resolve&structure&on&ion&versus&electron&spa;al&scales&
# Understanding&the&role&of&turbulence&is&also&an&important&mission&objec;ve&
# The&SMART&instrument&suite&has&unprecedented&temporal&resolu;on&for&in&situ&spaceJbased∥cles&and&fields&measurements&&
# MMS&has&an&open&data&policy&–&in&the&Spring&of&2016&scienceJgrade&data&will&be&made&available&to&the&public&within&one&month&of&acquisi;on&
MMS&–&Unprecedented&resolu;on&
UCLA#09/22/2015#18&
Through&planning&of&the&THEMIS&orbits&a&number&of&experiments&have&been&designed&in&the&next&2&years&to&study&reconnec;on,&its&drivers&and&its&effects&in&
conjunc;on&with&the&recently&launched&MMS&mission.&&&
THM&and&MMS&study&dayside&and&nightside&reconnec;on&simultaneously;&VAP&determines&geoeffec;veness&of&reconnec;on&flows;&
ARTEMIS&measures&global&energy&conversion&6
18
MMS
THEMIS VAP
ARTEMIS @55RE
Future&Opportuni;es&
UCLA#09/22/2015#19&
Saturn’s&magnetospheric&periodici;es&M.&Kivelson&
# RadioJfrequency&power&(SKR)&emised&&
From&Saturn’s&low&al;tude&magnetosphere&&is&modulated&at&~Saturn’s&rota;on&period.&
# The&magnetosphere&changes&size&and&&shape&at&the&same&period.&
# But&Saturn’s&magne;c&field&is&axially&&symmetric;&how&is&periodicity&imposed?&
# Measurements&show&that&the&periodic&&varia;ons&arise&from¤t&flowing&&at#high#equatorial#alOtude.&
# Source&of&modula;on¬&understood.&
Electric¤ts&must&couple&the&N&and&S&&ionospheres&to&each&other&&&to&magnetosphere.&
May&relate&to&angular&momentum&transfer&&
to&solar&wind.&
Dynamic power
spectrum of radiation 10-300 kHz
UCLA#09/22/2015#20&
###
Origins&of&the&Heliosphere:&SPP&and&SO&M.Velli,&C.&Russell&
Observations inside 20Rs:
• Coronal magnetic structure still channels the flow
• Waves, turbulence are strongest
• Temperature maximum.
• Collisional - Collisionless transition.
To determine the structure and dynamics of the Sun’s coronal magnetic field, understand how the solar corona and wind are heated and accelerated, and determine what mechanisms accelerate and transport energetic particles.
Solar&Orbiter&
UCLA#09/22/2015#
Venus Flyby #7 Nov 2, 2024
Mercury
Venus
Earth
Sun
First Perihelion at 35.7 RS
Nov 1, 2018
First Min Perihelion at 9.86 RS
Dec 19, 2024 Venus Flyby #1 Sept 28, 2018
Venus Flyby #2 Dec 22, 2019
Venus Flyby #3 Jul 6, 2020
Venus Flyby #4 Feb 16, 2021
Venus Flyby #5 Oct 11, 2021
Venus Flyby #6 Aug 16, 2023
Launch July 31, 2018
21
SPP&mission&trajectory&
UCLA#09/22/2015#22&
Joint&SPP&–&SO&observa;ons&
UCLA#09/22/2015#23&
z− << z+ δρ /ρ <<1 δ | B |<<| b |
Trace&the&flow&of&energy&that&heats&the&solar&corona&&and&accelerates&&the&solar&wind&&
UCLA#09/22/2015#24&
Solar&Wind&Turbulence&and&Complexity&J.&Weygand,&M.&Kivelson&
• Mauve:&Max/Min&complexity&curves.&Black:&Fractal&Brownian&mo;on.&
Red:&Helios&at&0.4&AU&@&6&sec&res.&IMF&total.&Blue:&Helios&at&0.95&AU&@&6&sec&res.&IMF&total.&
Red&curve&is&quadra;c&fit.&Helios&at&0.4&AU&has&on&ave.&higher&complexity&than&Helios&at&0.95&AU.&
• Is&this&evolu;on&of&chaos/turbulence&with&increasing&distance&from&the&Sun?&
UCLA#09/22/2015#
Exci;ng&Space&Plasma&Posters&!&
• Vassilis&Angelopoulos:&“Electromagne;c&energy&conversion&at&reconnec;on&fronts”&
• Xiaojia&Zhang:&“Predominance&of&ECH&wave&contribu;on&to&diffuse&aurora&in&Earth's&outer&magnetosphere”&&——>&ECH?&
• Jiang&Liu:&“Plasma&accelera;on&in&the&inner&magnetosphere&from&localized&dipolaring&flux&bundles.”&
• Yukinaga&Miyashita:&“Development&of&the&nearJEarth&magnetoJtail&and&the&auroral&arc&associated&with&substorm&onset:&Evidence&for&a&new&model”&
• Anna&Tenerani:&“Trigger&of&Fast&Reconnec;on&via&Current&Sheet&Collapse”&
• Fulvia&Pucci:&“Fast&Magne;c&Reconnec;on:&the&Hall&effect”&• Ray&Walker:&“Numerical&Simula;on&Studies&of&Magnetotail&Reconnec;on”&&
&