讲座信息

讲座题目：Nature and Prediction of Solar Cycle Variability

讲座嘉宾：姜杰（北京航空航天大学 教授）

讲座主持人：沈芳（中国科学院国家空间科学中心）

时间：10月18日10点

地点：线上 腾讯会议 411-8560-2478 (点此入会）   

          线下 中关村九章大厦A701   

                                                                               

讲座摘要

Solar activity follows an approximately 11-year cycle, known as the solar cycle. Solar cycles vary in amplitude and duration,which have a significant impact on both the space climate. Whether solar cycle variability is dominated by deterministic chaos orstochastic perturbations remains an open question. In this talk, I will provide a brief overview of the solar cycle and solar dynamo. Then I will present our recent work aimed at understanding nature of solar cycle variability. It is based on aone-dimensional iterative map,  incorporating recent advance in the observed nonlinearity and stochasticity of the cycle. We demonstrate that deterministic chaos is absent in the nonlinear system, regardless of model parameters. The synthesized solar cycles generated by the iterative map exhibit a probability density function similar to that of observed normal cycles, supporting the dominant role of stochasticity in solar cycle variability. We also explore the Gnevyshev-Ohl rule and its generation mechanism. Furthermore, the iterative map provides a quick and efficient tool for predicting the range of the subsequent cycle strength when an ongoing cycle amplitude is known. Due to stochasticity, a solar cycle loses almost all its original information after 3 or 4 cycles. Finally, I will discuss the ongoing solar cycle 25 and its predictions at the end of my talk.

嘉宾介绍

姜杰，北京航空航天大学教授、博士生导师2007年从国家天文台获得博士学位，之后在德国马普学会太阳系研究所和国家天文台学习或工作。主要从事太阳(恒星)磁周期发电机理论，以及长周期太阳活动对日球层影响等方面的研究。