A New TanSat XCO2 Global Product towards Climate Studies

The 1st Chinese carbon dioxide(CO2)monitoring satellite mission,TanSat,was launched in 2016.The 1st TanSat global map of CO2 dry-air mixing ratio(XCO2)measurements over land was released as version 1 data product with an accuracy of 2.11 ppmv(parts per million by volume).In this paper,we introduce a new(version 2)TanSat global XCO2 product that is approached by the Institute of Atmospheric Physics Carbon dioxide retrieval Algorithm for Satellite remote sensing(IAPCAS),and the European Space Agency(ESA)Climate Change Initiative plus(CCI+)TanSat XCO2 product by University of Leicester Full Physics(UoL-FP)retrieval algorithm.The correction of the measurement spectrum improves the accuracy(−0.08 ppmv)and precision(1.47 ppmv)of the new retrieval,which provides opportunity for further application in global carbon flux studies in the future.Inter-comparison between the two retrievals indicates a good agreement,with a standard deviation of 1.28 ppmv and a bias of−0.35 ppmv.

A New Global Solar-induced Chlorophyll Fluorescence(SIF)Data Product from TanSat Measurements

The Chinese Carbon Dioxide Observation Satellite Mission(TanSat)is the third satellite for global CO2 monitoring and is capable of detecting weak solar-induced chlorophyll fluorescence(SIF)signals with its advanced technical characteristics.Based on the Institute of Atmospheric Physics Carbon Dioxide Retrieval Algorithm for Satellite Remote Sensing(IAPCAS)platform,we successfully retrieved the TanSat global SIF product spanning the period of March 2017 to February 2018 with a physically based algorithm.This paper introduces the new TanSat SIF dataset and shows the global seasonal SIF maps.A brief comparison between the IAPCAS TanSat SIF product and the data-driven SVD(singular value decomposition)SIF product is also performed for follow-up algorithm optimization.The comparative results show that there are regional biases between the two SIF datasets and the linear correlations between them are above 0.73 for all seasons.The future SIF data product applications and requirements for SIF space observation are discussed.

Direct Observations of Atmospheric Transport and Stratosphere-Troposphere Exchange from High-Precision Carbon Dioxide and Carbon Monoxide Profile Measurements

The balloon-borne Aircore campaign was conducted in Inner Mongolia,China,on June 13 and 142018,which detected carbon dioxide(CO2)and carbon monoxide(CO)profiles from surface to 24 km,showing strong positive and negative correlations between 8 km and 10 km on 13 and 14 June,respectively.Backward trajectories,meteorological analyses,and CO2 horizontal distributions were combined to interpret this phenomenon.The results indicated that the source region experienced a stratospheric intrusion and exhibited a large horizontal CO2 gradient;namely,lower CO concentrations corresponded to higher CO2 concentrations and vice versa.The laminar structure with multiple origins resulted in the highly negative correlation between CO2 and CO in the upper troposphere on 14 June.The contribution of stratospheric air mass to the upper troposphere and that of tropospheric air mass to the lower stratosphere were 26.7%and24.3%,respectively,based on a mass balance approach.Another interesting phenomenon is that CO2 and CO concentrations increased substantially at approximately 8 km on 13 June.An analysis based on the backward trajectory implied that the air mass possibly came from anthropogenic sources.The slope of CO2/CO representing the anthropogenic sources was 87.3 ppm ppm-1.In addition,the CO2 profile showed that there was a large CO2 gradient of 4 ppm km-1 within the boundary layer on 13 June,and this gradient disappeared on 14 June.

Development of automatic and efficient immuno-separator of foodborne pathogenic bacteria using magnetophoresis and magnetic mixing

In recent years,the outbreaks of foodborne diseases caused by pathogenic bacteria have made considerable economic losses and shown a threat to public health.The key to prevent and control these diseases is fast screening of pathogenic bacteria,which is usually performed with three procedures:sample collection,bacteria separation and bacteria detection.For sample collection,the national standard methods are often employed.For bacteria detection,currently available methods such as Polymerase Chain Reaction and Enzyme Linked Immuno-Sorbent Assay are often used.For bacteria separation,traditional methods such as filtration and centrifugation are not capable to specifically separate the target bacteria.However,food samples are very complicated and require efficient pretreatment for bacteria separation and concentration to achieve accurate and reliable results.The conventional immune magnetic separation method can be used to specifically separate the bacteria,but it still cannot meet the requirements for food sample pretreatment due to very low concentration of target bacteria in food.Therefore,this study developed an automatic and efficient immuno-separator of foodborne bacteria based on magnetophoresis and magnetic mixing,and E.coli O157:H7 was used as research model.A magnetic mixer was applied to facilitate the immunoreaction between the immune magnetic nanoparticles and the target bacteria cells,and a magnetophoretic separation tubing was utilized for magnetophoretic separation of the magnetic bacteria.Under the optimal mixing time of 20 min and the optimal flow rate of 50μL/min,the separation efficiency of E.coli O157:H7 could be more than 90%,showing that the developed immuno-separator is promising to be applied for efficient separation of foodborne bacteria and can be easily extended for separation of other biological targets by using their specific antibodies.