Abstract Preliminary results from the measurement of potential gradient (PG) for the period of March 2018–February 2019 at the University of Kashmir, Srinagar, (34° 03′ N, 74° 51’ E, 1585 m amsl) India is reported. The annual mean diurnal variation of PG represents typical double-maxima pattern with the primary maximum at 0900–1000 LT and the secondary maximum at 1900–2000 LT which is in accordance with the measurements at different continental stations. The primary maximum of PG and its extended duration is explained by the sunrise effect due to increasing surface temperature, the development of surface convection and hence the boundary layer probably favour the uplifting of the surface aerosols. The higher PG values measured at Kashmir valley were explained with the height of the measurement from the surface and the role of mountain-valley winds circulation. Monthly mean PG showed the higher value during December and minimum in June and the amplitude variations were attributed to the local PM concentrations. PG is found to be highly influenced by PM2.5 compared to PM10, due to the high suspension duration in the ambient air. Measurement of PM2.5 to Srinagar showed higher values in December followed by the November and January under the strong inversion layer formation in Kashmir valley with the westerly winds apart from an increase in the local tourist activity. The measured PG values and its observed variations are explained considering the role of aerosol concentration, atmospheric mixing and mountain-valley wind circulations. The present results are comparable with measurements of PG at different continental stations. The level of aerosols and site location shows variation in amplitude as well as temporal shift.

中文翻译：

---

斯利那加（印度）喜马拉雅西北部克什米尔山谷大气电场的首次观测

摘要 报告了 2018 年 3 月至 2019 年 2 月期间在印度斯利那加克什米尔大学（北纬 34 度 51 分，东经 74 度 51 分，海拔 1585 米）测量电位梯度 (PG) 的初步结果。PG 的年平均日变化代表典型的双极大值模式，初级最大值在 0900-1000 LT，次要最大值在 1900-2000 LT，这与不同大陆站的测量结果一致。由于地表温度升高、地表对流的发展以及边界层可能有利于地表气溶胶的抬升，因此可以通过日出效应来解释 PG 的主要最大值及其持续时间的延长。在克什米尔山谷测量到的较高 PG 值可以用从地表测量的高度和山谷风环流的作用来解释。月平均 PG 值在 12 月最高，6 月最低，幅度变化归因于当地 PM 浓度。与 PM10 相比，PG 受 PM2.5 的影响较大，因为它在环境空气中的悬浮持续时间较长。斯利那加的 PM2.5 测量值在 12 月较高，随后是 11 月和 1 月，在克什米尔山谷形成强烈逆温层的情况下，西风以及当地旅游活动增加。考虑到气溶胶浓度、大气混合和山谷风环流的作用，解释了测量的 PG 值及其观察到的变化。目前的结果与不同大陆站的 PG 测量结果具有可比性。气溶胶水平和站点位置显示出振幅和时间偏移的变化。