No abstract

The primary objective of the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) mission is to study the climate impact of clouds and aerosols in the atmosphere. However, recent studies have demonstrated that CALIPSO also collects information about the ocean subsurface. The objective of this study is to estimate the ocean subsurface backscatter from CALIPSO lidar measurements. The effects of the lidar receiver's transient response on the attenuated backscatter were first removed in order to obtain the correct attenuated backscatter profile. The empirical relationship between sea surface lidar backscatter and wind speed was used to estimate the theoretical ocean surface backscatter. Then the twoway atmospheric transmittance was estimated as the ratio between the corrected ocean surface backscatter and the theoretical one. The ocean subsurface backscatter was finally derived from the subsurface attenuated backscatter divided by the two-way atmospheric transmittance. Significant relationships between integrated subsurface backscatter and chlorophyll-a concentration and between integrated subsurface backscatter and particulate organic carbon were found, which indicate a potential use of CALIPSO lidar to estimate global chlorophyll-a and particulate organic carbon concentrations.

BackgroundThe epidemiology of local viral etiologies is essential for the management of viral respiratory tract infections. Limited data are available in China to describe the epidemiology of viral respiratory infections, especially in small–medium cities and rural areas.ObjectivesTo determine the viral etiology and seasonality of acute respiratory infections in hospitalized children, a 3-year study was conducted in Shenzhen, China.MethodsNasopharyngeal aspirates from eligible children were collected. Influenza and other respiratory viruses were tested by molecular assays simultaneously. Data were analyzed to describe the frequency and seasonality.ResultsOf the 2025 children enrolled in the study, 971 (48·0%) were positive for at least one viral pathogen, in which 890 (91·7%) were <4 years of age. The three most prevalent viruses were influenza A (IAV; 35·8%), respiratory syncytial virus (RSV; 30·5%) and human rhinovirus (HRV; 21·5%). Co-infections were found in 302 cases (31·1%), and dual viral infection was dominant. RSV, HRV and IAV were the most frequent viral agents involved in co-infection. On the whole, the obvious seasonal peaks mainly from March to May were observed with peak strength varying from 1 year to another.ConclusionsThis study provides a basic profile of the epidemiology of acute respiratory viral infection in hospitalized children in Shenzhen. The spectrum of viruses in the study site is similar to that in other places, but the seasonality is closely related to geographic position, different from that in big cities in northern China and neighboring Hong Kong.

No abstract