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.

先前资助的研究表明，北方半球冬季气旋的强度随着全球大气电路中电流（Jz）的变化而变化，该电流由太阳风引起的几个独立的外部发电机驱动。外部驱动因素是宇宙线通量的变化，太阳风磁扇区边界交叉点处沉淀相对论电子通量的减少，（现在称为日光层电流片，或HCS交叉，与几天的低太阳风速度有关）;和太阳质子事件。研究还表明，南极和北极的表面压力对太阳风电场的响应，进入极冠两个极冠的压力响应相反，在每个极冠的太阳风电场的Jz响应相反。另一个结果是，7个北极站和11个南极站的地面气压显示出对全球回路内部发电机（低纬度，高度带电的对流云）的日常变化的几百帕水平的响应。观测结果是一致的概念模型，其中JZ存款正电荷的电导率梯度与液滴浓度梯度在层云的顶部，和存款负电荷类似的基础上，这样的云，根据高斯定律。这种电荷附着在水滴和气溶胶粒子上，包括云凝结核（CCN）和冰形成核（IFN），并影响这些和其他气溶胶粒子被云滴清除的速度，并可能导致云量，降水和大气辐射平衡的变化。该项目将把研究范围扩大到南半球，检查南半球的气象数据，以检验与Jz变化有关的气旋变化。将对太阳风速度的观测结果进行检查，以确定速度的降低，这将表明概念模型所建议的相对论性电子沉淀引起的变化，而不是日光层电流片交叉引起的变化，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气象对银河宇宙线通量福布什减少的反应。概念模式将用于预报由于Jz内部产生的变化而引起的冬季风暴的涡度，以及云量和降水变化的响应。这些由云层中的电荷引起的大气动力学变化目前都没有包括在全球预报或气候模式中。由于这一项目，根据对影响Jz的主要产生地区雷暴活动的预测和空间天气的预测，可以改进对冬季风暴强度的日常预测。