Based on the optimal interpolation (OI) algorithm, a daily fusion product of high-resolution global ocean columnar atmospheric water vapor with a resolution of 0.25° was generated in this study from multisource remote sensing observations. The product covers the period from 2003 to 2018, and the data represent a fusion of microwave radiometer observations, including those from the Special Sensor Microwave Imager Sounder (SSMIS), WindSat, Advanced Microwave Scanning Radiometer for Earth Observing System sensor (AMSR-E), Advanced Microwave Scanning Radiometer 2 (AMSR2), and HY-2A microwave radiometer (MR). The accuracy of this water vapor fusion product was validated using radiosonde water vapor observations. The comparative results show that the overall mean deviation (Bias) is smaller than 0.6 mm; the root mean square error (RMSE) and standard deviation (SD) are better than 3 mm, and the mean absolute deviation (MAD) and correlation coefficient (R) are better than 2 mm and 0.98, respectively.

Spartina alterniflora (S. alterniflora) rapidly invade new habitats by seed jumping propagation, and the early invasion process is characterized by discrete large patches and diffuse distribution small-scale patches. Monitoring these early-invasion-stage patches is very important for effectively stopping the S. alterniflora invasion trends. In this study, a long time series of high spatial resolution (0.5 and 1 m) satellite remote sensing images from 2010 to 2020 were used to monitor the early invasion period of S. alterniflora . Using remote sensing technology, the early invasion behavior of S. alterniflora at patch scale was monitored and analyzed in the Yellow River Delta with the object-oriented image segmentation and support vector machine classification methods. The results indicate that the discrete patches were incorporated into bigger patches or gathering regions within a few years: 56.13% of the independent large patches lasted only for 1 year, and only 0.25% of which can last for 10 years. Second, we newly found out that the newborn S. alterniflora seedlings are uniformly distributed between discrete large patches and then quickly aggregate into a large gathering area within the next 2 years. Third, for the area that was undergoing invasion, the mean S. alterniflora coverage rate was stable at approximately 50%. Fourth, dominant factors that determined the invasion trend of S. alterniflora are the elevation of the intertidal zone, the tidal channel distribution and the topographic changes caused by S. alterniflora invasion.

Climate change has profoundly affected global ecological security. The most vulnerable region on Earth is the high-latitude Arctic. Identifying the changes in vegetation coverage and glaciers in high-latitude Arctic coastal regions is important for understanding the process and impact of global climate change. Ny-Ålesund, the northern-most human settlement, is typical of these coastal regions and was used as a study site. Vegetation and glacier changes over the past 35 years were studied using time series remote sensing data from Landsat 5/7/8 acquired in 1985, 1989, 2000, 2011, 2015 and 2019. Site survey data in 2019, a digital elevation model from 2009 and meteorological data observed from 1985 to 2019 were also used. The vegetation in the Ny-Ålesund coastal zone showed a trend of declining and then increasing, with a breaking point in 2000. However, the area of vegetation with coverage greater than 30% increased over the whole study period, and the wetland moss area also increased, which may be caused by the accelerated melting of glaciers. Human activities were responsible for the decline in vegetation cover around Ny-Ålesund owing to the construction of the town and airport. Even in areas with vegetation coverage of only 13%, there were at least five species of high-latitude plants. The melting rate of five major glaciers in the study area accelerated, and approximately 82% of the reduction in glacier area occurred after 2000. The elevation of the lowest boundary of the five glaciers increased by 50–70 m. The increase in precipitation and the average annual temperature after 2000 explains the changes in both vegetation coverage and glaciers in the study period.