Abstract The climatological characteristics of biomass burning over the western Indo-Gangetic Plain (IGP) are examined during the post-monsoon (October-November) season from 2001-2018 using the Moderate resolution Imaging Spectrometer (MODIS) fire products. The intensity of the biomass burning are estimated from the fire pixels detected by the MODIS satellites in the form of fire counts, surface brightness temperature, and fire radiative power. Such biomass burning are mostly affected over Lahore and Patiala region of the western IGP. These fire products are examined along with optical and physical properties of aerosols and its radiative forcing estimated from AErosol RObotic NETwork (AERONET) data. Due to non-availability of long-term aerosol data, the study was performed only at Lahore (AERONET) and Patiala (MODIS) of the western IGP region. The current study shows increasing trends of average brightness temperature by 16% year−1 over Patiala and 14% year−1 over Lahore, which enhances the aerosol optical depth (AOD) by 3%–7% year−1 over the study region. The sphericity of the fine-mode aerosols are rising from 23% to 61% during non-fire to fire events and the dominance of fine-mode aerosols are observed during the active fire events. Further, the absorptivity of AOD (at 440 nm) has enhanced from 0.07 to 0.14 during non-fire to fire events. Asymmetric parameter (AS) of fine-mode aerosol increases from 0.65 to 0.68 during non-fire to active fire events. The characteristics of elevated aerosol layers due to the active fire events are clearly distinguished from the non-fire events within 0-2 km above the surface as noticed from high aerosol extinction and attenuated back scatter coefficients, obtained from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). Absorbing aerosols associated from biomass-burning contribute to the surface radiative forcing by -173.96 ± 47 W m−2 and atmospheric forcing by 123.57 ± 41 W m−2 over Lahore. The impact of the biomass-burning over Lahore has making the atmosphere more warming by 3.50 ± 1.14 K Day−1. The estimated heating rates (HR) in the atmosphere are rising during both fire and non-fire events by 3.79% and 3.44% per year, respectively.

中文翻译：

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印度-恒河平原活跃火灾事件期间气溶胶的光学和物理特性：对气溶胶辐射强迫的影响

摘要 使用中分辨率成像光谱仪 (MODIS) 火灾产品检查了 2001 年至 2018 年季风后（10 月至 11 月）季节期间印度-恒河平原 (IGP) 西部燃烧生物量的气候特征。生物质燃烧的强度是根据 MODIS 卫星检测到的火灾像素以火灾计数、表面亮度温度和火灾辐射功率的形式估计的。这种生物质燃烧主要在 IGP 西部的拉合尔和帕蒂亚拉地区受到影响。这些火灾产物与气溶胶的光学和物理特性及其根据气溶胶机器人网络 (AERONET) 数据估计的辐射强迫一起进行检查。由于长期气溶胶数据不可用，该研究仅在 IGP 西部地区的拉合尔 (AERONET) 和帕蒂亚拉 (MODIS) 进行。目前的研究表明，帕蒂亚拉的平均亮温增加了 16% 年-1 年，拉合尔增加了 14% 年-1，这使研究区域的气溶胶光学深度 (AOD) 增加了 3%–7% 年-1 年。在非火灾到火灾事件期间，细模式气溶胶的球形度从 23% 上升到 61%，在活跃火灾事件期间观察到细模式气溶胶的主导地位。此外，在非火灾到火灾事件期间，AOD（440 nm）的吸收率从 0.07 提高到 0.14。在非火灾到活跃火灾事件期间，精细模式气溶胶的非对称参数 (AS) 从 0.65 增加到 0.68。从云-气溶胶激光雷达和红外线获得的高气溶胶消光和衰减后向散射系数注意到，由于活跃火灾事件引起的升高的气溶胶层特征与地表以上 0-2 公里范围内的非火灾事件明显不同探路者卫星观测 (CALIPSO)。与生物质燃烧相关的吸收气溶胶对拉合尔的表面辐射强迫贡献 -173.96 ± 47 W m-2 和大气强迫 123.57 ± 41 W m-2。拉合尔上空燃烧生物质的影响使大气升温 3.50 ± 1.14 K Day−1。在火灾和非火灾事件期间，估计的大气升温率 (HR) 分别以每年 3.79% 和 3.44% 的速度上升。从云气溶胶激光雷达和红外探路者卫星观测 (CALIPSO) 获得。与生物质燃烧相关的吸收气溶胶对拉合尔的表面辐射强迫贡献 -173.96 ± 47 W m-2 和大气强迫 123.57 ± 41 W m-2。拉合尔上空燃烧生物质的影响使大气升温 3.50 ± 1.14 K Day−1。在火灾和非火灾事件期间，估计的大气升温率 (HR) 分别以每年 3.79% 和 3.44% 的速度上升。从云气溶胶激光雷达和红外探路者卫星观测 (CALIPSO) 获得。与生物质燃烧相关的吸收气溶胶对拉合尔的表面辐射强迫贡献 -173.96 ± 47 W m-2 和大气强迫 123.57 ± 41 W m-2。拉合尔上空燃烧生物质的影响使大气升温 3.50 ± 1.14 K Day−1。在火灾和非火灾事件期间，估计的大气升温率 (HR) 分别以每年 3.79% 和 3.44% 的速度上升。