Monitoring ice variations in Qinghai Lake from 1979 to 2016 using passive microwave remote sensing data
Monitoring ice variations in Qinghai Lake from 1979 to 2016 using passive microwave remote sensing data
复制标题
利用被动微波遥感数据监测1979-2016年青海湖冰层变化
DOI：
10.1016/j.scitotenv.2017.07.027
复制
发表时间：
2017-12-31
影响因子：
9.8
通讯作者：
Duan, Zheng
中科院分区：
文献类型：
--
作者：
Cai, Yu;Ke, Chang-Qing;Duan, Zheng
湖冰是气候变化的敏感指标。基于湖冰和湖水亮度温度之间的差异，被动微波数据可以用来监测湖冰的变化。利用扫描多通道微波辐射计(SMMR)和专用传感器微波成像仪(SSM/I)的被动微波亮度温度数据，提取了青海湖1979-2016年与湖冰有关的4个特征数据(年冻结开始、冻结完成、消融开始和消融完成日期)，重点分析了湖冰的长时间序列变化。计算了相应的冰冻持续时间、消融持续时间、完全冰冻持续时间和冰盖持续时间。利用中分辨率成像光谱仪(MODIS)的日积雪数据，验证了被动微波数据的精度。验证分析表明，由MODIS数据和被动微波数据得到的冰冻开始日期、消融开始日期和消融完成日期具有很强的一致性(R-2为0.70~0.85，平均绝对误差为2.25~3.94天)，冰盖持续时间误差也较小(相对误差为2.95%，MAE=3.13天)，表明被动微波数据的结果是可靠的。结果表明，青海湖冰期推迟，消融日期提前。38年来，冻结开始日期和冻结完成日期分别推迟了6.16天和2.27天，而消融开始日期和完成日期分别提前了11.24天和14.09天。冰冻时间和消融时间分别缩短3.89天和2.85天，完全冰冻时间和覆冰时间分别缩短14.84天和21.21天。冬季冰盖持续时间与平均气温呈显著负相关。(C)2017爱思唯尔B.V.保留所有权利。
Lake ice is a sensitive indicator of climate change. Based on the disparities between the brightness temperatures of lake ice and water, passive microwave data can be used to monitor the ice variations of a lake. With focus on the analysis of long time series variability of lake ice, this study extracts four characteristic dates related to lake ice (the annual freeze start, freeze completion, ablation start and ablation completion dates) for Qinghai Lake from 1979 to 2016 using Scanning Multichannel Microwave Radiometer (SMMR) and Special Sensor Microwave Imager (SSM/I) passive microwave brightness temperature data. The corresponding freezing duration, ablation duration, complete freezing duration and ice coverage duration are calculated. Applying Moderate Resolution Imaging Spectroradiometer (MODIS) daily snow products, the accuracy of the results derived from passive microwave data is validated. The validation analysis shows a strong agreement (R-2 ranges from 0.70 to 0.85, mean absolute error (MAE) ranges from 2.25 to 3.94 days) in the freeze start, ablation start, and ablation completion dates derived from the MODIS data and passive microwave data; the ice coverage duration also has a small error (relative error (RE) = 2.95%, MAE = 3.13 days), suggesting that the results obtained from passive microwave data are reliable. The results show that the freezing dates of Qinghai Lake have been delayed and the ablation dates have advanced. Over 38 years, the freeze start date and freeze completion date have been pushed back by 6.16 days and 2.27 days, respectively, while the ablation start date and ablation completion date have advanced by 11.24 days and 14.09 days, respectively. The freezing duration and ablation duration have shortened by 3.89 days and 2.85 days, respectively, and the complete freezing duration and ice coverage duration have shortened by 14.84 days and 21.21 days, respectively. There is a significant negative correlation between the ice coverage duration and the mean air temperature in winter. (C) 2017 Elsevier B.V. All rights reserved.