Winter Thermospheric Weather Study

冬季热层天气研究

• 批准号: 8800867
• 负责人: Maura Hagan
• 金额: --
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-06-01 至 1990-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8800867&HistoricalAwards=false
• 关键词: Winter; Thermospheric; Weather; Study

The upper atmosphere above about 85 km altitude is called the Thermosphere, because it is much hotter than the Mesosphere below, with temperatures ranging from about 500K at night at minimum solar activity to about 2000K for daytime maximum solar activity. This can be contrasted with Mesospheric temperatures in the range 150 to 200K. The high Thermospheric temperatures arise from several sources; the absorption of solar UV and X-rays during the day; the heating due to particle precipitation and electric fields associated with auroral activity; and the dissipation of the energy from gravity waves and tides that propagates up from the lower atmosphere. Measurements of the temperature of the thermosphere are made by optical interferometers and incoherent scatter radars, and latitudinal profiles are now available from a chain of four sites extending from the equator (Jicamarca in Peru) to Greenland (Sondestrom). During a January 1986 campaign anomalously low temperatures were observed at Arecibo (Puerto Rico), in comparison with results for the other sites, and it has been theorized that tides (or the absence thereof) are the cause. This award is to perform numerical modelling using the facilities of Millstone Hill Observatory to test the hypothesis.

大约85公里高度的高度大气称为热层，因为它比下面的中层高得多，温度从最小太阳能活动的夜间约500k到约2000k的白天最大太阳能活动。 这可以与150至200K范围内的中层温度形成对比。 高热层温度来自多种来源。白天的太阳紫外线和X射线吸收；由于颗粒降水和与极光活性相关的电场引起的加热；从重力波和潮汐中耗散能量，从下层大气中传播。 热层温度的测量是通过光学干涉仪和不连贯的散射雷达进行的，现在可以从从赤道（秘鲁的Jicamarca）延伸到格陵兰（Sondestrom）的四个地点的链中获得纬度。 与其他地点的结果相比，在1986年1月的一场运动中，在Arecibo（波多黎各）观察到了低温，并且从理论上讲，潮汐（或缺失）是原因。 该奖项是使用Millstone Hill天文台的设施进行数值建模来检验假设。