IMF-driven change to the Antarctic tropospheric temperature due to the global atmospheric electric circuit
IMF-driven change to the Antarctic tropospheric temperature due to the global atmospheric electric circuit
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DOI：
10.1016/j.jastp.2017.08.027
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发表时间：
2017-08
影响因子：
1.9
通讯作者：
M. Lam;M. Freeman;G. Chisham
中科院分区：
文献类型：
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作者：
M. Lam;M. Freeman;G. Chisham
利用美国国家环境预报中心(NCEP)/美国国家大气研究中心（NCAR）的再分析数据，研究了与行星际磁场（IMF）黎明-黄昏分量变化相关的南极平均对流层温度异常。我们发现，地理纬度≤- 70°的平均对流层温度异常在约0.7 K处达到峰值，在1 000和500 hPa气压之间的5%水平（海拔0.1-5.6 km）具有统计学意义，并且相对于IMF的时间滞后长达7天。与1 000 ~ 600 hPa （~ 0.1 ~ 4.2 km）相比，500 hPa （~ 5.6 km）的气温异常峰值出现在更大的滞后时间，这可能表明该信号是垂直传播的。在IMF和高纬度气压异常（即Mansurov效应）之间的相关性中，对流层内的快速响应和可能的垂直传播特征已被发现，具有较高的统计显著性（1%）。对于IMF与对流层之间0 ~ 6天的时间滞后，高度在1 000 ~ 700 hPa （~ 0.1 ~ 3 km）之间，高度高度异常值与相应的气温异常值之间的关系具有高度统计显著性（1%水平），与标准的大气温度减速率一致。我们的结论是，我们已经确定了南极对流层曼苏洛夫效应的温度特征。由于这些对流层异常与电离层电势的由驱动异常有关，我们进一步得出结论，它们是由imf引起的全球大气电路（GEC）变化引起的。我们的结果支持电离层电位的变化作用于对流层的观点，这可能是通过GEC的下行电流对对流层云的变化而产生的。
We use National Centers for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR) reanalysis data to investigate the Antarctic mean tropospheric temperature anomaly associated with changes in the dawn-dusk componentByof the interplanetary magnetic field (IMF). We find that the mean tropospheric temperature anomaly for geographical latitudes ≤ −70° peaks at about 0.7 K and is statistically significant at the 5% level between air pressures of 1 000 and 500 hPa (∼0.1–5.6 km altitude above sea level) and for time lags with respect to the IMF of up to 7 days. The peak values of the air temperature anomaly occur at a greater time lag at 500 hPa (∼5.6 km) than at 1 000 - 600 hPa (∼0.1–4.2 km), which may indicate that the signature propagates vertically. The characteristics of prompt response and possible vertical propagation within the troposphere have previously been seen in the correlation between the IMF and high-latitude air pressure anomalies, known as the Mansurov effect, at higher statistical significances (1%). For time lags between the IMF and the troposphere of 0–6 days and altitudes between 1 000 and 700 hPa (∼0.1–3 km), the relationship between highly statistically significant (1% level) geopotential height anomaly values and the corresponding air temperature anomaly values is consistent with the standard lapse rate in atmospheric temperature. We conclude that we have identified the temperature signature of the Mansurov effect in the Antarctic troposphere. Since these tropospheric anomalies have been associated withBy-driven anomalies in the electric potential of the ionosphere, we further conclude that they are caused by IMF-induced changes to the global atmospheric electric circuit (GEC). Our results support the view that variations in the ionospheric potential act on the troposphere, possibly via the action of consequent variations in the downwards current of the GEC on tropospheric clouds.