Role of biochar in raising blue carbon stock capacity of salt marshes

Salt marshes are an important blue carbon ecosystem, with surprisingly fast carbon accumulation rates that are 40 times higher than those of terrestrial forests. In recent decades, salt marshes have suffered great degradation and loss all over the world. The idea to enhance carbon stock in salt marshes(so-called blue carbon) using biochar (so-called black carbon) has recently been proposed. Although experiments and observations remain limited, significant enhancements in soil organic carbon and plant growth have been documented in most case studies. However, due to the limited number of observations and their relatively short time window ranging from months to less than one year, there still exists a knowledge gap regarding the process, mechanism, and effect of biochar in enhancing carbon stock in salt marshes. Future research is urgently needed in the following perspectives:1) exploring the relationship between carbon stock enhancement efficiency and biochar properties, 2) optimizing the physical and chemical properties of biochar to boost its efficiency, and 3)studying the in-situ responses of complex carbon pools to biochar addition, especially under tidal conditions and over a longer period of time.

Impact of Atmospheric Transmittance and NLTE Correction on Simulation of High Spectral Infrared Atmospheric Sounder onboard FY-3E

With the launch of the first civilian early-morning orbit satellite Fengyun-3E(FY-3E),higher demands are placed on the accuracy of radiative transfer simulations for hyperspectral infrared data.Therefore,several key issues are investigated in the paper.First,the accuracy of the fast atmospheric transmittance model implemented in the Advanced Research and Modeling System(ARMS)has been evaluated with both the line-by-line radiative transfer model(LBLRTM)and the actual satellite observations.The results indicate that the biases are generally less than 0.25 K when compared to the LBLRTM,while below 1.0 K for the majority of the channels when compared to the observations.However,during both comparisons,significant biases are observed in certain channels.The accuracy of Hyperspectral Infrared Atmospheric Sounder-II(HIRAS-II)onboard FY-3E is comparable to,and even superior to that of the Cross-track Infrared Sounder(CrIS)onboard NOAA-20.Furthermore,apodization is a crucial step in the processing of hyperspectral data in that the apodization function is utilized as the instrument channel spectral response function to produce the satellite channel-averaged transmittance.To further explore the difference between the apodized and unapodized simulations,Sinc function is adopted in the fast transmittance model.It is found that the use of Sinc function can make the simulations fit the original satellite observations better.When simulating with apodized observations,the use of Sinc function exhibits larger deviations compared to the Hamming function.Moreover,a correction module is applied to minimize the impact of Non-Local Thermodynamic Equilibrium(NLTE)in the shortwave infrared band.It is verified that the implementation of the NLTE correction model leads to a significant reduction in the bias between the simulation and observation for this band.

Transcriptome profiling and RXR gene family identification reveals the molecular mechanism of rapid aging after spawning of cuttlefish Sepiella japonica

Sepiella japonica is a worldwide marine cuttlefish species of high economic value.S.japonica routinely modifying behaviors in reproductive life,such as rapid aging until death after spawning,has been recognized in artificial breeding.However,reproductive behavior at the level of genes is rarely reported,thus,the research on the genetic basis of behavior,reproduction,and artificial breeding was limited.We applied RNA-seq in different stages of reproduction to investigate the reason of rapid aging after spawning,pre-maturity,pre-spawning after maturity,and post-spawning.The retinoid X receptor(RXR)gene family in S.japonica was identified,and 1343–1452 differentially expressed genes(DEGs)in all 3 stages of reproductive life were identified from pairwise m RNA comparisons.Furthermore,through the GO term and KEGG analysis,S.japonica could handle neuronal development and network formation before maturity and have a functional degradation of neural communication,signal transduction,vision,and gene expression after spawning.Eight Sj RXRαs have been identified and they played different roles in growth development or reproduction.Therefore,the regulation of several channels and receptors is the intrinsic molecular mechanism of rapid aging after spawning in S.japonica.This study revealed the survival strategy and provided fundamental data on the level of genes for understanding the reproductive behavior and the reproduction of S.japonica.

Algal community structure prediction by machine learning

The algal community structure is vital for aquatic management.However,the complicated environmental and biological processes make modeling challenging.To cope with this difficulty,we investigated using random forests(RF)to predict phytoplankton community shifting based on multi-source environmental factors(including physicochemical,hydrological,and meteorological variables).The RF models robustly predicted the algal communities composed by 13 major classes(Bray-Curtis dissimilarity=9.2±7.0%,validation NRMSE mostly<10%),with accurate simulations to the total biomass(validation R^(2)>0.74)in Norway's largest lake,Lake Mjosa.The importance analysis showed that the hydro-meteorological variables(Standardized MSE and Node Purity mostly>0.5)were the most influential factors in regulating the phytoplankton.Furthermore,an in-depth ecological interpretation uncovered the interactive stress-response effect on the algal community learned by the RF models.The interpretation results disclosed that the environmental drivers(i.e.,temperature,lake inflow,and nutrients)can jointly pose strong influence on the algal community shifts.This study highlighted the power of machine learning in predicting complex algal community structures and provided insights into the model interpretability.

Shipborne oceanic high-spectral-resolution lidar for accurate estimation of seawater depth-resolved optical properties

Lidar techniques present a distinctive ability to resolve vertical structure of optical properties within the upper water column at both day-and night-time.However,accuracy challenges remain for existing lidar instruments due to the ill-posed nature of elastic backscatter lidar retrievals and multiple scattering.Here we demonstrate the high performance of,to the best of our knowledge,the first shipborne oceanic high-spectral-resolution lidar(HSRL)and illustrate a multiple scattering correction algorithm to rigorously address the above challenges in estimating the depth-resolved diffuse attenuation coefficient Kd and the particulate backscattering coefficient bbp at 532 nm.HSRL data were collected during day-and night-time within the coastal areas of East China Sea and South China Sea,which are connected by the Taiwan Strait.Results include vertical profiles from open ocean waters to moderate turbid waters and first lidar continuous observation of diel vertical distribution of thin layers at a fixed station.The root-mean-square relative differences between the HSRL and coincident in situ measurements are 5.6%and 9.1%for Kd and bbp,respectively,corresponding to an improvement of 2.7-13.5 and 4.9-44.1 times,respectively,with respect to elastic backscatter lidar methods.Shipborne oceanic HSRLs with high performance are expected to be of paramount importance for the construction of 3D map of ocean ecosystem.

Synergistic effect between Er-doped MoS_(2)nanosheets and interfacial Mo-N coupling phases for enhanced electrocatalytic hydrogen evolution

Hydrogen production via electrochemical water splitting is a promising and green technology.As one of the most representative transition metal sulfides layered materials,Molybdenum disulfide(MoS_(2))has immense potential for the hydrogen evolution reaction(HER).We successfully prepared a nitrogen-doped carbon(NC)in situ-grown erbium-doped MoS_(2)polyhedral structure(Er-MoS_(2)/NC)that incorporates an interfacial Mo-N coupling phase.