L. Xiang, K. H. Lee, L. C. Lee, D. J. Wu, L. Chen, H. Q. Feng, Q. H. Li, G. Q. Zhao
{"title":"与太阳风中阿尔法束不稳定性有关的质子温度各向异性约束","authors":"L. Xiang, K. H. Lee, L. C. Lee, D. J. Wu, L. Chen, H. Q. Feng, Q. H. Li, G. Q. Zhao","doi":"10.1029/2023JA032398","DOIUrl":null,"url":null,"abstract":"<p>Solar wind observations in the space of the proton temperature anisotropy <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>T</mi>\n <mrow>\n <mi>p</mi>\n <mo>⊥</mo>\n </mrow>\n </msub>\n <mo>/</mo>\n <msub>\n <mi>T</mi>\n <mrow>\n <mi>p</mi>\n <mo>‖</mo>\n </mrow>\n </msub>\n </mrow>\n <annotation> ${T}_{p\\perp }/{T}_{p\\Vert }$</annotation>\n </semantics></math> versus parallel proton beta <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>β</mi>\n <mrow>\n <mi>p</mi>\n <mo>‖</mo>\n </mrow>\n </msub>\n </mrow>\n <annotation> ${\\beta }_{p\\Vert }$</annotation>\n </semantics></math> always show a distorted rhomboid-like pattern, where the boundaries of this plot are associated with several instabilities. However, the specific mechanism on the constraint of the proton temperature anisotropy is unclear in the low-beta <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>β</mi>\n <mrow>\n <mi>p</mi>\n <mo>‖</mo>\n </mrow>\n </msub>\n <mo><</mo>\n <mn>1</mn>\n </mrow>\n <annotation> ${\\beta }_{p\\Vert }< 1$</annotation>\n </semantics></math> plasma. In this work, we study the kinetic instabilities driven by proton temperature anisotropy and alpha beam with the Vlasov theory and investigate the nonlinear evolution of these instabilities with hybrid simulations. We also compare the theoretical and simulation results with Wind observations. The alpha beam with drift velocity <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>v</mi>\n <mi>α</mi>\n </msub>\n <mo>/</mo>\n <msub>\n <mi>v</mi>\n <mi>A</mi>\n </msub>\n <mo>></mo>\n <mn>1</mn>\n </mrow>\n <annotation> ${v}_{\\alpha }/{v}_{A} > 1$</annotation>\n </semantics></math> leads to a new kind of Alfvén/ion-cyclotron instability (<span></span><math>\n <semantics>\n <mrow>\n <mi>α</mi>\n </mrow>\n <annotation> $\\alpha $</annotation>\n </semantics></math>A/IC instability) in the region of <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>β</mi>\n <mrow>\n <mi>p</mi>\n <mo>‖</mo>\n </mrow>\n </msub>\n <mo>≤</mo>\n <mn>0.2</mn>\n </mrow>\n <annotation> ${\\beta }_{p\\Vert }\\le 0.2$</annotation>\n </semantics></math>. In the region of <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>β</mi>\n <mrow>\n <mi>p</mi>\n <mo>‖</mo>\n </mrow>\n </msub>\n <mo>≤</mo>\n <mn>0.2</mn>\n </mrow>\n <annotation> ${\\beta }_{p\\Vert }\\le 0.2$</annotation>\n </semantics></math> and <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>T</mi>\n <mrow>\n <mi>p</mi>\n <mo>⊥</mo>\n </mrow>\n </msub>\n <mo><</mo>\n <msub>\n <mi>T</mi>\n <mrow>\n <mi>p</mi>\n <mo>‖</mo>\n </mrow>\n </msub>\n </mrow>\n <annotation> ${T}_{p\\perp }< {T}_{p\\Vert }$</annotation>\n </semantics></math>, the nonlinear wave-particle interaction through the <span></span><math>\n <semantics>\n <mrow>\n <mi>α</mi>\n </mrow>\n <annotation> $\\alpha $</annotation>\n </semantics></math>A/IC instability can decelerate alpha beams to <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>v</mi>\n <mi>α</mi>\n </msub>\n <mo>/</mo>\n <msub>\n <mi>v</mi>\n <mi>A</mi>\n </msub>\n <mo>≤</mo>\n <mn>1</mn>\n </mrow>\n <annotation> ${v}_{\\alpha }/{v}_{A}\\le 1$</annotation>\n </semantics></math> and result in the anti-correlation between <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>T</mi>\n <mrow>\n <mi>p</mi>\n <mo>⊥</mo>\n </mrow>\n </msub>\n <mo>/</mo>\n <msub>\n <mi>T</mi>\n <mrow>\n <mi>p</mi>\n <mo>‖</mo>\n </mrow>\n </msub>\n </mrow>\n <annotation> ${T}_{p\\perp }/{T}_{p\\Vert }$</annotation>\n </semantics></math> and <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>β</mi>\n <mrow>\n <mi>p</mi>\n <mo>‖</mo>\n </mrow>\n </msub>\n </mrow>\n <annotation> ${\\beta }_{p\\Vert }$</annotation>\n </semantics></math>. In the region of <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>β</mi>\n <mrow>\n <mi>p</mi>\n <mo>‖</mo>\n </mrow>\n </msub>\n <mo>≤</mo>\n <mn>0.2</mn>\n </mrow>\n <annotation> ${\\beta }_{p\\Vert }\\le 0.2$</annotation>\n </semantics></math> and <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>T</mi>\n <mrow>\n <mi>p</mi>\n <mo>⊥</mo>\n </mrow>\n </msub>\n <mo>≥</mo>\n <msub>\n <mi>T</mi>\n <mrow>\n <mi>p</mi>\n <mo>‖</mo>\n </mrow>\n </msub>\n </mrow>\n <annotation> ${T}_{p\\perp }\\ge {T}_{p\\Vert }$</annotation>\n </semantics></math>, the nonlinear wave-particle interaction through the <span></span><math>\n <semantics>\n <mrow>\n <mi>α</mi>\n </mrow>\n <annotation> $\\alpha $</annotation>\n </semantics></math>A/IC instability further leads to slight increase of <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>T</mi>\n <mrow>\n <mi>p</mi>\n <mo>⊥</mo>\n </mrow>\n </msub>\n <mo>/</mo>\n <msub>\n <mi>T</mi>\n <mrow>\n <mi>p</mi>\n <mo>‖</mo>\n </mrow>\n </msub>\n </mrow>\n <annotation> ${T}_{p\\perp }/{T}_{p\\Vert }$</annotation>\n </semantics></math>. The present results provide a potential mechanism for regulating the proton temperature anisotropy in the low-beta plasma with <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>T</mi>\n <mrow>\n <mi>p</mi>\n <mo>⊥</mo>\n </mrow>\n </msub>\n <mo><</mo>\n <msub>\n <mi>T</mi>\n <mrow>\n <mi>p</mi>\n <mo>‖</mo>\n </mrow>\n </msub>\n </mrow>\n <annotation> ${T}_{p\\perp }< {T}_{p\\Vert }$</annotation>\n </semantics></math> in the solar wind.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":null,"pages":null},"PeriodicalIF":2.6000,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Proton Temperature Anisotropy Constraint Associated With Alpha Beam Instability in the Solar Wind\",\"authors\":\"L. Xiang, K. H. Lee, L. C. Lee, D. J. Wu, L. Chen, H. Q. Feng, Q. H. Li, G. Q. Zhao\",\"doi\":\"10.1029/2023JA032398\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>Solar wind observations in the space of the proton temperature anisotropy <span></span><math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>T</mi>\\n <mrow>\\n <mi>p</mi>\\n <mo>⊥</mo>\\n </mrow>\\n </msub>\\n <mo>/</mo>\\n <msub>\\n <mi>T</mi>\\n <mrow>\\n <mi>p</mi>\\n <mo>‖</mo>\\n </mrow>\\n </msub>\\n </mrow>\\n <annotation> ${T}_{p\\\\perp }/{T}_{p\\\\Vert }$</annotation>\\n </semantics></math> versus parallel proton beta <span></span><math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>β</mi>\\n <mrow>\\n <mi>p</mi>\\n <mo>‖</mo>\\n </mrow>\\n </msub>\\n </mrow>\\n <annotation> ${\\\\beta }_{p\\\\Vert }$</annotation>\\n </semantics></math> always show a distorted rhomboid-like pattern, where the boundaries of this plot are associated with several instabilities. However, the specific mechanism on the constraint of the proton temperature anisotropy is unclear in the low-beta <span></span><math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>β</mi>\\n <mrow>\\n <mi>p</mi>\\n <mo>‖</mo>\\n </mrow>\\n </msub>\\n <mo><</mo>\\n <mn>1</mn>\\n </mrow>\\n <annotation> ${\\\\beta }_{p\\\\Vert }< 1$</annotation>\\n </semantics></math> plasma. In this work, we study the kinetic instabilities driven by proton temperature anisotropy and alpha beam with the Vlasov theory and investigate the nonlinear evolution of these instabilities with hybrid simulations. We also compare the theoretical and simulation results with Wind observations. The alpha beam with drift velocity <span></span><math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>v</mi>\\n <mi>α</mi>\\n </msub>\\n <mo>/</mo>\\n <msub>\\n <mi>v</mi>\\n <mi>A</mi>\\n </msub>\\n <mo>></mo>\\n <mn>1</mn>\\n </mrow>\\n <annotation> ${v}_{\\\\alpha }/{v}_{A} > 1$</annotation>\\n </semantics></math> leads to a new kind of Alfvén/ion-cyclotron instability (<span></span><math>\\n <semantics>\\n <mrow>\\n <mi>α</mi>\\n </mrow>\\n <annotation> $\\\\alpha $</annotation>\\n </semantics></math>A/IC instability) in the region of <span></span><math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>β</mi>\\n <mrow>\\n <mi>p</mi>\\n <mo>‖</mo>\\n </mrow>\\n </msub>\\n <mo>≤</mo>\\n <mn>0.2</mn>\\n </mrow>\\n <annotation> ${\\\\beta }_{p\\\\Vert }\\\\le 0.2$</annotation>\\n </semantics></math>. In the region of <span></span><math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>β</mi>\\n <mrow>\\n <mi>p</mi>\\n <mo>‖</mo>\\n </mrow>\\n </msub>\\n <mo>≤</mo>\\n <mn>0.2</mn>\\n </mrow>\\n <annotation> ${\\\\beta }_{p\\\\Vert }\\\\le 0.2$</annotation>\\n </semantics></math> and <span></span><math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>T</mi>\\n <mrow>\\n <mi>p</mi>\\n <mo>⊥</mo>\\n </mrow>\\n </msub>\\n <mo><</mo>\\n <msub>\\n <mi>T</mi>\\n <mrow>\\n <mi>p</mi>\\n <mo>‖</mo>\\n </mrow>\\n </msub>\\n </mrow>\\n <annotation> ${T}_{p\\\\perp }< {T}_{p\\\\Vert }$</annotation>\\n </semantics></math>, the nonlinear wave-particle interaction through the <span></span><math>\\n <semantics>\\n <mrow>\\n <mi>α</mi>\\n </mrow>\\n <annotation> $\\\\alpha $</annotation>\\n </semantics></math>A/IC instability can decelerate alpha beams to <span></span><math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>v</mi>\\n <mi>α</mi>\\n </msub>\\n <mo>/</mo>\\n <msub>\\n <mi>v</mi>\\n <mi>A</mi>\\n </msub>\\n <mo>≤</mo>\\n <mn>1</mn>\\n </mrow>\\n <annotation> ${v}_{\\\\alpha }/{v}_{A}\\\\le 1$</annotation>\\n </semantics></math> and result in the anti-correlation between <span></span><math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>T</mi>\\n <mrow>\\n <mi>p</mi>\\n <mo>⊥</mo>\\n </mrow>\\n </msub>\\n <mo>/</mo>\\n <msub>\\n <mi>T</mi>\\n <mrow>\\n <mi>p</mi>\\n <mo>‖</mo>\\n </mrow>\\n </msub>\\n </mrow>\\n <annotation> ${T}_{p\\\\perp }/{T}_{p\\\\Vert }$</annotation>\\n </semantics></math> and <span></span><math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>β</mi>\\n <mrow>\\n <mi>p</mi>\\n <mo>‖</mo>\\n </mrow>\\n </msub>\\n </mrow>\\n <annotation> ${\\\\beta }_{p\\\\Vert }$</annotation>\\n </semantics></math>. In the region of <span></span><math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>β</mi>\\n <mrow>\\n <mi>p</mi>\\n <mo>‖</mo>\\n </mrow>\\n </msub>\\n <mo>≤</mo>\\n <mn>0.2</mn>\\n </mrow>\\n <annotation> ${\\\\beta }_{p\\\\Vert }\\\\le 0.2$</annotation>\\n </semantics></math> and <span></span><math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>T</mi>\\n <mrow>\\n <mi>p</mi>\\n <mo>⊥</mo>\\n </mrow>\\n </msub>\\n <mo>≥</mo>\\n <msub>\\n <mi>T</mi>\\n <mrow>\\n <mi>p</mi>\\n <mo>‖</mo>\\n </mrow>\\n </msub>\\n </mrow>\\n <annotation> ${T}_{p\\\\perp }\\\\ge {T}_{p\\\\Vert }$</annotation>\\n </semantics></math>, the nonlinear wave-particle interaction through the <span></span><math>\\n <semantics>\\n <mrow>\\n <mi>α</mi>\\n </mrow>\\n <annotation> $\\\\alpha $</annotation>\\n </semantics></math>A/IC instability further leads to slight increase of <span></span><math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>T</mi>\\n <mrow>\\n <mi>p</mi>\\n <mo>⊥</mo>\\n </mrow>\\n </msub>\\n <mo>/</mo>\\n <msub>\\n <mi>T</mi>\\n <mrow>\\n <mi>p</mi>\\n <mo>‖</mo>\\n </mrow>\\n </msub>\\n </mrow>\\n <annotation> ${T}_{p\\\\perp }/{T}_{p\\\\Vert }$</annotation>\\n </semantics></math>. The present results provide a potential mechanism for regulating the proton temperature anisotropy in the low-beta plasma with <span></span><math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>T</mi>\\n <mrow>\\n <mi>p</mi>\\n <mo>⊥</mo>\\n </mrow>\\n </msub>\\n <mo><</mo>\\n <msub>\\n <mi>T</mi>\\n <mrow>\\n <mi>p</mi>\\n <mo>‖</mo>\\n </mrow>\\n </msub>\\n </mrow>\\n <annotation> ${T}_{p\\\\perp }< {T}_{p\\\\Vert }$</annotation>\\n </semantics></math> in the solar wind.</p>\",\"PeriodicalId\":15894,\"journal\":{\"name\":\"Journal of Geophysical Research: Space Physics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.6000,\"publicationDate\":\"2024-10-10\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Geophysical Research: Space Physics\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1029/2023JA032398\",\"RegionNum\":2,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ASTRONOMY & ASTROPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Geophysical Research: Space Physics","FirstCategoryId":"89","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1029/2023JA032398","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 0
摘要
在质子温度各向异性 T p ⊥ / T p ‖ ${T}_{p\perp }/{T}_{p\Vert }$ 与平行质子β β p ‖ ${\beta }_{p\Vert }$ 空间的太阳风观测总是显示出一种扭曲的菱形图案,这种图案的边界与几种不稳定性有关。然而,在低β p ‖ < 1 ${\beta }_{p\Vert }< 1$等离子体中,质子温度各向异性约束的具体机制尚不清楚。在这项工作中,我们用弗拉索夫理论研究了质子温度各向异性和α束驱动的动力学不稳定性,并用混合模拟研究了这些不稳定性的非线性演化。我们还将理论和模拟结果与风云观测结果进行了比较。漂移速度为v α / v A > 1 ${v}_{\alpha }/{v}_{A} > 1$的α束在β p ‖ ≤ 0.2 ${\beta }_{p\Vert }\le 0.2$的区域导致了一种新的阿尔弗/离子-回旋不稳定性(α $\alpha $ A/IC 不稳定性)。在 β p ‖≤ 0.2 ${beta }_{p\Vert }\le 0.2$ 和 T p ⊥ < T p ‖ ${T}_{p\perp }< {T}_{p\Vert }$ 区域,通过 α $\alpha $ A/IC 不稳定性产生的非线性波粒相互作用会使α束减速到 v α / v A ≤ 1 ${v}_{\alpha }/{v}_{A}\le 1$,并导致 T p ⊥ / T p ‖ ${T}_{p\perp }/{T}_{p\Vert }$ 和 β p ‖ ${beta }_{p\Vert }$ 之间的反相关性。在 β p ‖ ≤ 0.2 ${beta }_{p\Vert }\le 0 的区域内。
Proton Temperature Anisotropy Constraint Associated With Alpha Beam Instability in the Solar Wind
Solar wind observations in the space of the proton temperature anisotropy versus parallel proton beta always show a distorted rhomboid-like pattern, where the boundaries of this plot are associated with several instabilities. However, the specific mechanism on the constraint of the proton temperature anisotropy is unclear in the low-beta plasma. In this work, we study the kinetic instabilities driven by proton temperature anisotropy and alpha beam with the Vlasov theory and investigate the nonlinear evolution of these instabilities with hybrid simulations. We also compare the theoretical and simulation results with Wind observations. The alpha beam with drift velocity leads to a new kind of Alfvén/ion-cyclotron instability (A/IC instability) in the region of . In the region of and , the nonlinear wave-particle interaction through the A/IC instability can decelerate alpha beams to and result in the anti-correlation between and . In the region of and , the nonlinear wave-particle interaction through the A/IC instability further leads to slight increase of . The present results provide a potential mechanism for regulating the proton temperature anisotropy in the low-beta plasma with in the solar wind.