Analysis of Present Research on the WSA Solar Wind Model
-
摘要: Wang-Sheely-Arge （WSA）模型是对准稳态太阳风的经验和物理相结合的描述，其利用观测的日面磁图作为输入，可以提前3到4天预测L1点处的太阳风速度和行星际磁场极性.WSA模型是在WS模型的基础上经过若干改进形成的实时预报模式，之后又借鉴Distance from the Coronal Hole Boundary （DCHB）模型的参数，进一步改进了太阳风速度关系式，形成了目前常见的形式.WSA经验模型由日冕磁场模型、太阳风速度关系式和一维运动学模型三部分组成.在实际应用过程中，基本步骤包括观测磁图预处理、日冕三维磁场反演、计算日冕磁场参数、计算太阳风的速度分布和将太阳风映射到1AU等环节.在发展过程中，WSA模型经历了一些细节上的调整变化，例如观测磁图数据的来源、日冕磁场模型的类型、经验速度关系中自由系数的取值等.许多研究对如何改善模型的预报效果进行了探索.Abstract: The Wang-Sheeley-Arge (WSA) model is an empirical model that can predict the background solar wind speed and Interplanetary Magnetic Field (IMF) polarity on the Earth. It utilizes the line-of-sight synoptic solar magnetograms as input to give predictions about 3 to 4 days in advance. It is an improved version of the original Wang and Sheeley (WS) model. The relationship was generalized according to the parameters of the Coronal Hole Boundary (DCHB) model. The solar wind velocity is first determined at a certain height by the expansion factor of the magnetic field and the minimum angular distance that an open field footpoint lies from nearest coronal hole boundary. And then a simple 1-D modified kinematic model (1-DMK), which includes an ad hoc method to account for stream interactions, is used to transport the wind from the corona out to the Earth. In the course of development, the WSA model has been improved gradually in the details, such as the source of synoptic magnetograms, the type of coronal magnetic field model, the values of free parameters in velocity relation, the way of mapping the solar wind to earth and so on. Many studies were devoted to improve the prediction accuracy of the WSA model, and it is widely used now in many Magnetohydrodynamic (MHD) solar wind model.
-
Key words:
- WSA model /
- Solar wind /
- Coronal magnetic field
-
[1] ARGE C N, PIZZO V J. Improvement in the prediction of solar wind conditions using near-real time solar magnetic field updates[J]. J. Geophys. Res., 2000, 105(A5):10465-10479 [2] ARGE C N, ODSTRCIL D, PIZZO V J, et al. Improved method for specifying solar wind speed near the sun[C]//Proceedings of the Tenth International Solar Wind Conference. New York:AIP, 2003, 679:190-193 [3] KRIEGER A S, TIMOTHY A F, ROELOF E C. A coronal hole and its identification as the source of a high velocity solar wind stream[J]. Solar Phys., 1973, 29(2):505-525 [4] NOLTE J T, KRIEGER A S, TIMOTHY A F, et al. Coronal holes as sources of solar wind[J]. Solar Phys., 1976, 46(2):303-322 [5] LEVINE R H, ALTSCHULER M D, HARVEY J W. Solar sources of the interplanetary magnetic field and solar wind[J]. J. Geophys. Res., 1977, 82(1):1061-1065 [6] WANG Y M, SHEELEY JR N R. Solar wind speed and coronal flux-tube expansion[J]. Astrophys. J., 1990, 355:726-732 [7] ALTSCHULER M D, NEWKIRK JR G. Magnetic fields and the structure of the solar corona. I:methods of calculating coronal fields[J]. Solar Phys., 1969, 9(1):131-149 [8] SCHATTEN K H, WILCOX J M, NESS N F. A model of interplanetary and coronal magnetic fields[J]. Solar Phys., 1969, 6(3):442-455 [9] WANG Y M, SHEELEY JR N R, PHILLIPS J L, et al. Solar wind stream interactions and the wind speed-expansion factor relationship[J]. Astrophys. J., 1997, 488 (1):L51-L54 [10] RILEY P, LINKER J A, MIKIĆ Z. An empirically-driven global MHD model of the solar corona and inner heliosphere[J]. J. Geophys. Res., 2001, 106(A8):15889-15901 [11] SCHATTEN K H. Current sheet magnetic model for the solar corona[J]. Cosmic Electrodyn., 1971, 2:232-245 [12] ARGE C N, LUHMANN J G, ODSTRCIL D, et al. Stream structure and coronal sources of the solar wind during the May 12th, 1997 CME[J]. J. Atmos. Solar-Terres. Phys., 2004, 66(15-16):1295-1309 [13] SCHWENN R. Solar wind sources and their variations over the solar cycle[J]. Space Sci. Rev., 2006, 124(1/2/3/4):51-76 [14] RILEY P, BEN-NUN M, LINKER J A, et al. A multi-observatory inter-comparison of line-of-sight synoptic solar magnetograms[J]. Solar Phys., 2014, 289(3):769-792 [15] ZHAO X, HOEKSEMA J T. Predicting the heliospheric magnetic field using the current sheet-source surface model[J]. Adv. Space Res., 1995, 16(9):181-184 [16] LOW B C. Some recent developments in the theoretical dynamics of magnetic fields[J]. Solar Phys., 1985, 100(1-2):309-331 [17] TRAN T. Improving the Predictions of Solar Wind Speed and Interplanetary Magnetic Field at the Earth[D]. Los Angeles:University of California, 2009 [18] MCGREGOR S L, HUGHES W J, ARGE C N, et al. The distribution of solar wind speeds during solar minimum:calibration for numerical solar wind modeling constraints on the source of the slow solar wind[J]. J. Geophys. Res., 2011, 116(A3):A03101 [19] WIENGARTEN T, KLEIMANN J, FICHTNER H, et al. Cosmic ray transport in heliospheric magnetic structures. I. Modeling background solar wind using the CRONOS magnetohydrodynamic code[J]. Astrophys. J., 2014, 788(1):80 [20] EDWARDS S J, YEATES A R, BOCQUET F X, et al. Influence of non-potential coronal magnetic topology on solar-wind models[J]. Solar Phys., 2015, 290(10):2791-2808 [21] RILEY P, LINKER J A, ARGE C N. On the role played by magnetic expansion factor in the prediction of solar wind speed[J]. Space Wea., 2015, 13(3):154-169 [22] OWENS M J, ARGE C N, SPENCE H E, et al. An event-based approach to validating solar wind speed predictions:high-speed enhancements in the Wang-Sheeley-Arge model[J]. J. Geophys. Res., 2005, 110(A12):A12105 [23] MCGREGOR S L, HUGHES W J, ARGE C N, et al. Analysis of the magnetic field discontinuity at the potential field source surface and Schatten Current Sheet interface in the Wang-Sheeley-Arge model[J]. J. Geophys. Res., 2008, 113(A8):A08112 [24] SUN Xudong, HOEKSEMA J T. A comparative study of different approaches and potential improvement to modeling the solar wind[C]//American Astronomical Society Meeting. Washington:American Astronomical Society, 2007, 39:142 [25] SUN X, HOEKSEMA J T. Modeling Solar wind Using the Newly Calibrated MDI Magnetic Field:1996-2008[R]. Florida:AGU Spring Meeting, 2008 [26] SUN X, LIU Y, HOEKSEMA J T, et al. A new method for polar field interpolation[J]. Solar Phys., 2011, 270(1):9-22 [27] SVALGAARD L, DUVALL JR T L, SCHERRER P H. The strength of the Sun's polar fields[J]. Solar Phys., 1978, 58(2):225-239 [28] WANG Y M, SHEELEY JR N R. Solar implications of ULYSSES interplanetary field measurements[J]. Astrophys. J., 1995, 447:L143-L146 [29] ARGE C N, HENNEY C J, KOLLER J, et al. Air force data assimilative photospheric flux transport (ADAPT) model[C]//Twelfth International Solar Wind Conference. Saint-Malo, France:AIP, 2010, 1216:343-346 [30] ARGE C N, HENNEY C J, KOLLER J, et al. Improving data drivers for coronal and solar wind models[C]//Proceedings of the 5th International Conference of Numerical Modeling of Space Plasma Flows. California:Astronomical Society of the Pacific, 2011, 444:99 [31] ARGE C N, HENNEY C J, HERNÁNDEZ I G, et al. Modeling the corona and solar wind using ADAPT maps that include far-side observations[C]//Proceedings of the Thirteenth International Solar Wind Conference. New York:AIP, 2013, 1539:11-14 [32] PODUVAL B, ZHAO X P. Validating solar wind prediction using the current sheet source surface model[J]. Astrophys. J. Lett., 2014, 782:L22 [33] COHEN O. Quantifying the difference between the flux-tube expansion factor at the source surface and at the Alfvén surface using a global MHD model for the solar wind[J]. Solar Phys., 2015, 290(8):2245-2263 [34] JONES S I, DAVILA J M, URITSKY V M. Image-optimized coronal magnetic field models[J]. Astrophys. J., 2017, 844(2):93 [35] JONES S I, DAVILA J M, URITSKY V M. Optimizing global coronal magnetic field models using image-based constraints[J]. Astrophys. J., 2016, 820(2):113 [36] PODUVAL B, ZHAO Xuepu. Discrepancies in the prediction of solar wind using potential field source surface model:an investigation of possible sources[J]. J. Geophys. Res., 2004, 109(A8):A08102 [37] TOTH G, VAN DER HOLST B, HUANG Z G. Obtaining potential field solutions with spherical harmonics and finite differences[J]. Astrophys. J., 2011, 732(2):102 [38] HOEKSEMA J T, WILCOX J M, SCHERRER P H. The structure of the heliospheric current sheet:1978-1982[J]. J. Geophys. Res., 1983, 88(A12):9910-9918 [39] SUN Xudong, HOEKSEMA J T. A new source surface radius in potential field modeling during the current weak solar minimum[C]//AGU Fall Meeting. Washington DC:AGU, 2009 [40] LEE C O, LUHMANN J G, HOEKSEMA J T, et al. Coronal field opens at lower height during the solar cycles 22 and 23 minimum periods:IMF comparison suggests the source surface should be lowered[J]. Solar Phys., 2011, 269(2):367-388 [41] ARDEN W M, NORTON A A, SUN X. A "breathing" source surface for cycles 23 and 24[J]. J. Geophys. Res., 2014, 119(3):1476-1485 [42] ZHAO X P, HOEKSEMA J T, RICH N B. Modeling the radial variation of coronal streamer belts during sunspot ascending phase[J]. Adv. Space Res., 2002, 29(3):411-416 [43] ZHAO X P, HOEKSEMA J T. The magnetic field at the inner boundary of the heliosphere around solar minimum[J]. Solar Phys., 2010, 266(2):379-390 [44] RILEY P, LUHMANN J G. Interplanetary signatures of unipolar streamers and the origin of the slow solar wind[J]. Solar Phys., 2012, 277(2):355-373 [45] RILEY P, LIONELLO R. Mapping solar wind streams from the Sun to 1AU:a comparison of techniques[J]. Solar Phys., 2011, 270(2):575-592 [46] ODSTRCIL D. Modeling 3-D solar wind structure[J]. Adv. Space Res., 2003, 32(4):497-506 [47] FRY C D, DRYER M, SMITH Z, et al. Forecasting solar wind structures and shock arrival times using an ensemble of models[J]. J. Geophys. Res., 2003, 108(A2):1070 [48] DETMAN T, SMITH Z, DRYER M, et al. A hybrid heliospheric modeling system:background solar wind[J]. J. Geophys. Res., 2006, 111(A7):A07102 [49] WIENGARTEN T, KLEIMANN J, FICHTNER H, et al. MHD simulation of the inner-heliospheric magnetic field[J]. J. Geophys. Res., 2013, 118(1):29-44 [50] MERKIN V G, LYON J G, LARIO D, et al. Time-dependent magnetohydrodynamic simulations of the inner heliosphere[J]. J. Geophys. Res., 2015, 121(4):2866-2890 -
-
计量
- 文章访问数: 1869
- HTML全文浏览量: 119
- PDF下载量: 596
-
被引次数:
0(来源:Crossref)
0(来源:其他)
下载:
