ON POTENTIAL-FIELD MODELS OF THE SOLAR CORONA

被引:431
作者
WANG, YM
SHEELEY, NR
机构
[1] Code 4172, E. O. Hulburt Ctr. for Space Res., Naval Research Laboratory, Washington
关键词
INTERPLANETARY MEDIUM; SUN; CORONA; MAGNETIC FIELDS;
D O I
10.1086/171430
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
The current-free approximation has been widely used to infer the magnetic structure of the solar corona from magnetograph observations. In such calculations, the potential field is usually matched directly to the observed line-of-sight component of the photospheric field. However, this procedure is invalid because the magnetograph measurements apply to deep atmospheric layers where the magnetic field is nonpotential and (for observations made in the Fe I lambda-5250 line) nearly radial. A better approach is to match only the radial component of the potential field to the photospheric data (corrected for line-of-sight projection on the assumption that the field lines are radially oriented), while allowing a discontinuity in the tangential field components. The implied current sheet is a mathematical idealization of the finite "boundary layer" within which the rapidly diverging field lines make their transition to a potential configuration. This procedure yields much stronger polar fields than the conventional line-of-sight method and resolves a number of discrepancies between earlier potential field calculations and observations of polar coronal holes, the brightness distribution of the K-corona, and the shape of the interplanetary current sheet.
引用
收藏
页码:310 / 319
页数:10
相关论文
共 53 条
[1]   NEW TECHNIQUE FOR DETERMINATION OF CORONAL MAGNETIC-FIELDS - FIXED MESH SOLUTION TO LAPLACES EQUATION USING LINE-OF-SIGHT BOUNDARY-CONDITIONS [J].
ADAMS, J ;
PNEUMAN, GW .
SOLAR PHYSICS, 1976, 46 (01) :185-203
[2]   HIGH-RESOLUTION MAPPING OF MAGNETIC-FIELD OF SOLAR CORONA [J].
ALTSCHULER, MD ;
LEVINE, RH ;
STIX, M ;
HARVEY, J .
SOLAR PHYSICS, 1977, 51 (02) :345-375
[3]   MAGNETIC FIELDS AND STRUCTURE OF SOLAR CORONA .I. METHODS OF CALCULATING CORONAL FIELDS [J].
ALTSCHULER, MD ;
NEWKIRK, G .
SOLAR PHYSICS, 1969, 9 (01) :131-+
[4]  
Billings D. E., 1966, GUIDE SOLAR CORONA, P150
[5]   NUMERICAL-CALCULATION OF THOMSON SCATTERING FROM INHOMOGENEOUS MODELS OF CORONA, AND APPLICATION TO STREAMERS OF 1970 AND 1972 ECLIPSES [J].
BOHLIN, JD ;
GARRISON, LM .
SOLAR PHYSICS, 1974, 38 (01) :165-179
[6]   EXTREME-ULTRAVIOLET OBSERVATIONS OF CORONAL HOLES .1. LOCATIONS, SIZES AND EVOLUTION OF CORONAL HOLES, JUNE 1973 JANUARY 1974 [J].
BOHLIN, JD .
SOLAR PHYSICS, 1977, 51 (02) :377-398
[7]   QUADRUPOLE DISTORTIONS OF THE HELIOSPHERIC CURRENT SHEET IN 1976 AND 1977 [J].
BRUNO, R ;
BURLAGA, LF ;
HUNDHAUSEN, AJ .
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 1982, 87 (NA12) :339-346
[8]   THE CORONAL AND INTER-PLANETARY CURRENT SHEET IN EARLY 1976 [J].
BURLAGA, LF ;
HUNDHAUSEN, AJ ;
ZHAO, XP .
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 1981, 86 (NA11) :8893-8898
[9]  
Campbell W. W., 1923, PASP, V35, P163
[10]  
Chapman GA, 1968, IAU S, V35, P161