Analysis of Global Atmospheric Responses to Externally and Internally Driven Global Circuit Variability

全球大气对外部和内部驱动的全球环路变化的响应分析

• 批准号: 0836171
• 负责人: Brian Tinsley
• 金额: $ 30.97万
• 依托单位: University of Texas at Dallas
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0836171&HistoricalAwards=false
• 关键词: Analysis; Global; Atmospheric; Responses; Externally

Previous funded research has shown that the strength of winter cyclones in the Northern Hemisphere varies with changes in the current flow (Jz) in the global atmospheric electric circuit, driven by several independent external generators due to the solar wind. The external drivers are changes in cosmic ray flux, reductions in precipitating relativistic electron flux at solar wind magnetic sector boundary crossings, (now called heliospheric current sheet, or HCS crossings, that are associated with periods of several days of low solar wind speed); and solar proton events.The research also showed that surface pressure in both the Antarctic and Arctic responds to the solar wind electric field that penetrates into the polar caps. The pressure responses are opposite in the two polar caps, following the opposite Jz responses to the solar wind electric field in each polar cap. Another result was that the surface pressures in 7 Arctic stations and 11 Antarctic stations show responses at the level of a few hPa to the day-to-day changes in the internal generators of the global circuit (low latitude, highly electrified convective cloud). The observational results are consistent with a conceptual model in which Jz deposits positive charge in the conductivity gradients associated with droplet concentration gradients at the tops of layer clouds, and deposits negative charge similarly at the bases of such clouds, in accordance with Gauss's Law. This charge attaches to droplets and aerosol particles, including cloud condensation nuclei (CCN) and ice forming nuclei (IFN) and affects the rate at which these and other aerosol particles are scavenged by cloud droplets, and can lead to changes in cloud cover, precipitation, and the atmospheric radiation balance. This project will extend the research to the southern hemisphere by examining meteorological data for the southern hemisphere to test for cyclone variability related to Jz changes. Observations of the solar wind speeds will be examined for decreases in the speed which will indicate changes induced by relativistic electron precipitation, as suggested by the conceptual model, rather than heliospheric current sheet crossings, to improve the understanding of these links. Another component is to re-examine the meteorological responses to Forbush decreases of the galactic cosmic ray flux, using 20 years of more recent data. The conceptual model will be used to predict the vorticity of winter storms due to internally generated changes in Jz, as well as the responses of cloud cover and precipitation changes. None of these changes in atmospheric dynamics induced by electric charge in layer clouds are currently included in global forecast or climate models. As a result of this project, day-to-day forecasts of winter storm strength may be improved, based on forecasts of thunderstorm activity in the main generating regions, and forecasts of space weather, that affect Jz.

先前的资助研究表明，北半球冬季气旋的强度随着全球大气电路的电流流量（JZ）的变化而变化，这是由于太阳风而导致的几个独立的外发电机驱动。外部驱动因素是宇宙射线通量的变化，在太阳风磁扇形边界交叉处的降水相对论电子通量减少（现在称为Heliospereric电流板或HCS横梁，它们与低太阳风速低几天的时期有关）；这项研究还表明，南极和北极的表面压力均对渗透到极性盖的太阳风电场做出反应。遵循JZ对每个极性盖中太阳风电场的反应相反，压力响应在两个极盖中相反。另一个结果是，7个北极站和11个南极站的表面压力显示出对全球电路内部发电机（低纬度，高电动对流云）的日常变化的水平的响应。观察结果与一个概念模型一致，在该模型中，JZ在层云顶部与液滴浓度梯度相关的电导率梯度中沉积正电荷，并且根据高斯定律，在此类云的基础上类似地将负电荷沉积在此类云的基础上。该电荷附着在液滴和气溶胶颗粒上，包括云凝结核（CCN）和冰形成核（IFN），并影响这些和其他气溶胶颗粒被云滴清除的速率，并可能导致云覆盖，降水层和大气辐射平衡的变化。该项目将通过检查南半球的气象数据来测试与JZ变化有关的旋风变异性，将研究扩展到南半球。将检查太阳风速的观察结果，以降低速度的降低，这将表明相对论电子降水引起的变化，如概念模型而不是地球层电流板交叉口所示，以提高对这些联系的理解。另一个组成部分是使用20年的最新数据重新检查银河宇宙射线通量的气象反应。该概念模型将用于预测由于JZ内部产生的变化以及云覆盖物和降水变化的响应而导致的冬季风暴的涡度。层云中电荷引起的大气动力学的这些变化目前都不包括在全球预测或气候模型中。由于该项目的结果，根据主要发电区域雷暴活动以及影响JZ的太空天气的预测，可以改善冬季风暴强度的日常预测。