No abstract

No abstract

Indoor and outdoor particulate matter 2.5 (PM 2.5) concentrations were monitored in seven sampling sites: basketball stadium, hotel, shopping centre, research centre, commercial office, apartment building and villa, to determine the indoor and outdoor relationship of PM 2.5 mass concentration in the central area of Beijing from February 2014 to March 2014. The influence of four types of ventilation systems on indoor to outdoor (I/O) ratio of PM 2.5 concentration was evaluated. The measured results show that the mean I/O ratio of the seven locations was 0.36 when the outdoor PM 2.5 concentration was more than 150 mg/m 3 , and 1.1 when the outdoor PM 2.5 concentration was less than 100 mg/m 3 , which implies that people's activities could be the most likely factor rather than outdoor sources for elevated indoor PM 2.5 levels. The average I/O ratio was 0.69 for public buildings and 0.94 for residential homes, which illustrates that indoor PM 2.5 concentrations could be dominated by outdoor sources for residential homes. Approximately 90% of the outdoor particles were removed in public buildings equipped with fan-coil unit with air cleaning plus fresh air system. The results demonstrate the need to improve indoor air quality by using a proper ventilation system with air cleaning.

No abstract

Detailed mapping of landfast ice deformation can be used to characterize the rheological behavior of landfast ice effectively and to improve sea ice modeling subsequently. In order to analyze the characteristics, trends and causes of deformation comprehensively and accurately, the Sentinel-1A ascending and descending orbits data were used to detect the horizontal and vertical deformation of the fast ice in the Baltic Sea. Firstly, the fast ice edge lines were acquired through feature extraction with interferometric coherence images and SAR amplitude images. Then, the deformation transformed model was constructed according to the geometric relationship of multi-orbits deformation measurements. Finally, the landfast ice deformations were resolved and the horizontal and vertical deformations were obtained. The results showed that the maximum deformation was—44 cm in horizontal direction and 16 cm in vertical direction within the fast ice region of 960 km2 during the time from 2 to 16 February 2018. The southwest wind was the principal reason for the deformation, which made the deformation mainly occur in the horizontal direction from east to west. Moreover, the inner fast ice kept stable due to the protection of outer consolidated ice. The results showed that the deformation trend and characteristics can be better understood by using InSAR technology that was combined with multi-orbits SAR data to resolve and analyze the landfast ice deformation.