利用WRF（Weather research and forecasting）中尺度气象模式结合MODIS资料反演的植被覆盖度，并同化东北半干旱区近地面气象要素，对夏季东北半干旱区的辐射和能量传输过程进行模拟，并用2009年通榆站6-8月份的通量观测资料进行验证...利用WRF（Weather research and forecasting）中尺度气象模式结合MODIS资料反演的植被覆盖度，并同化东北半干旱区近地面气象要素，对夏季东北半干旱区的辐射和能量传输过程进行模拟，并用2009年通榆站6-8月份的通量观测资料进行验证。结果表明：通榆站模拟的向上／向下短波、向上／向下长波辐射与观测值吻合较好，相关系数分别为：0．86、0．85、0．73和0．88，偏差Bias均在36．7w／m^2以下，潜热、感热和地表热通量密度观测日积分值分别占净辐射的28．8％、53．4％和3．4％。WRF模式也能较好地模拟出东北半干旱区夏季地表辐射与能量分量的区域分布特征。展开更多
随着我国低空空域的陆续开放,低空飞行安全气象保障体系正被越来越多的研究学者所重视。京津冀地区无人机产业的发展在国内处于领军地位。基于WRF(Weather Research and Forecasting Model)中尺度数值模式,对2015—2019年京津冀地区气...随着我国低空空域的陆续开放,低空飞行安全气象保障体系正被越来越多的研究学者所重视。京津冀地区无人机产业的发展在国内处于领军地位。基于WRF(Weather Research and Forecasting Model)中尺度数值模式,对2015—2019年京津冀地区气象要素进行模拟,模拟结果与气象站观测数据进行误差对比分析,可为该地区无人机低空航路的飞行安全提供建议。结合无人机飞行限制因素,对京津冀地区无人机航路气象要素平均分布和平均垂直分布进行分析,结论如下:1)冬季、春季以及秋季白石山至东灵山出现风速5.5 m/s以上区域,可使无人机飞行产生剧烈晃动甚至炸机,在此区域内飞行应时刻注意风速变化。2)冬季京津冀全区为0℃及以下所控制,由于温度条件限制不适合无人机飞行,其余季节温度范围均在无人机电池正常工作范围之内。3)夏季京津冀地区降雨量大,应注意强降雨对无人机飞行造成的影响。4)垂直方向上低空空域内,冬季、春季以及秋季风速会对无人机飞行造成影响,冬季温度低于0℃不适合无人机进行低空作业。展开更多
The absorption coefficient of water is an important bio-optical parameter for water optics and water color remote sensing. However, scattering correction is essential to obtain accurate absorption coefficient values i...The absorption coefficient of water is an important bio-optical parameter for water optics and water color remote sensing. However, scattering correction is essential to obtain accurate absorption coefficient values in situ using the nine-wavelength absorption and attenuation meter AC9. Establishing the correction always fails in Case 2 water when the correction assumes zero absorption in the near-infrared(NIR) region and underestimates the absorption coefficient in the red region, which affect processes such as semi-analytical remote sensing inversion. In this study, the scattering contribution was evaluated by an exponential fitting approach using AC9 measurements at seven wavelengths(412, 440, 488, 510, 532, 555, and 715 nm) and by applying scattering correction. The correction was applied to representative in situ data of moderately turbid coastal water, highly turbid coastal water, eutrophic inland water, and turbid inland water. The results suggest that the absorption levels in the red and NIR regions are significantly higher than those obtained using standard scattering error correction procedures. Knowledge of the deviation between this method and the commonly used scattering correction methods will facilitate the evaluation of the effect on satellite remote sensing of water constituents and general optical research using different scatteringcorrection methods.展开更多
文摘利用WRF（Weather research and forecasting）中尺度气象模式结合MODIS资料反演的植被覆盖度，并同化东北半干旱区近地面气象要素，对夏季东北半干旱区的辐射和能量传输过程进行模拟，并用2009年通榆站6-8月份的通量观测资料进行验证。结果表明：通榆站模拟的向上／向下短波、向上／向下长波辐射与观测值吻合较好，相关系数分别为：0．86、0．85、0．73和0．88，偏差Bias均在36．7w／m^2以下，潜热、感热和地表热通量密度观测日积分值分别占净辐射的28．8％、53．4％和3．4％。WRF模式也能较好地模拟出东北半干旱区夏季地表辐射与能量分量的区域分布特征。
文摘随着我国低空空域的陆续开放,低空飞行安全气象保障体系正被越来越多的研究学者所重视。京津冀地区无人机产业的发展在国内处于领军地位。基于WRF(Weather Research and Forecasting Model)中尺度数值模式,对2015—2019年京津冀地区气象要素进行模拟,模拟结果与气象站观测数据进行误差对比分析,可为该地区无人机低空航路的飞行安全提供建议。结合无人机飞行限制因素,对京津冀地区无人机航路气象要素平均分布和平均垂直分布进行分析,结论如下:1)冬季、春季以及秋季白石山至东灵山出现风速5.5 m/s以上区域,可使无人机飞行产生剧烈晃动甚至炸机,在此区域内飞行应时刻注意风速变化。2)冬季京津冀全区为0℃及以下所控制,由于温度条件限制不适合无人机飞行,其余季节温度范围均在无人机电池正常工作范围之内。3)夏季京津冀地区降雨量大,应注意强降雨对无人机飞行造成的影响。4)垂直方向上低空空域内,冬季、春季以及秋季风速会对无人机飞行造成影响,冬季温度低于0℃不适合无人机进行低空作业。
基金Supported by the National Key Research and Development Program of China(Nos.2016YFB0501502,2016YFC1400903,2016YFB0500304)the National Natural Science Foundation of China(Nos.91638201,41276184,41325004,41471308,41571361)+1 种基金the High Resolution Earth Observation Systems of National Science and Technology Major Projects(No.41-Y20A31-9003-15/17)the Director Foundation of Institute of Remote Sensing and Digital Earth,Chinese Academy of Sciences(No.Y6SJ2100CX)
文摘The absorption coefficient of water is an important bio-optical parameter for water optics and water color remote sensing. However, scattering correction is essential to obtain accurate absorption coefficient values in situ using the nine-wavelength absorption and attenuation meter AC9. Establishing the correction always fails in Case 2 water when the correction assumes zero absorption in the near-infrared(NIR) region and underestimates the absorption coefficient in the red region, which affect processes such as semi-analytical remote sensing inversion. In this study, the scattering contribution was evaluated by an exponential fitting approach using AC9 measurements at seven wavelengths(412, 440, 488, 510, 532, 555, and 715 nm) and by applying scattering correction. The correction was applied to representative in situ data of moderately turbid coastal water, highly turbid coastal water, eutrophic inland water, and turbid inland water. The results suggest that the absorption levels in the red and NIR regions are significantly higher than those obtained using standard scattering error correction procedures. Knowledge of the deviation between this method and the commonly used scattering correction methods will facilitate the evaluation of the effect on satellite remote sensing of water constituents and general optical research using different scatteringcorrection methods.
