ABSTRACT In the context of intense interference from human activities and massive loss natural wetlands in coastal zones, it is crucial to understand behavioral ecology shorebirds for formulating targeted conservation measures. Based on satellite tracking remote sensing techniques, our research investigated activity pattern habitat selection characteristics Pied Avocet ( Recurvirostra avosetta ) Bohai Bay, China. The results showed that Avocets are relatively flexible Bay. There obvious...

The estimation accuracy of tidal harmonic constants is great significance to maritime traffic and port construction. However, due the long sampling period satellite altimeters, signals alias mesoscale ocean frequencies. As a result, analysis affected by environmental noise. In this study, influence variability (MOV) on was quantified analyzing 25 years altimeter data from Topex/Poseidon (T/P) Jason satellites in South China Sea (SCS). results indicated that absolute amplitude differences...

Abstract Here, we explored in depth the relationship among deterministic prediction skill, probabilistic skill and potential predictability. This was achieved by theoretical analyses and, particular, an analysis of long-term ensemble ENSO hindcast over 161 years from 1856 to 2016. First, a nonlinear monotonic between derived analysis, examined validated using hindcast. Further, co-variability predictability both perfect model assumption actual scenario. On these bases, investigated practice...

Abstract This study provided an extension to the latest version of Lamont-Doherty Earth Observation (LDEO5) prediction system. First, ensemble coupled data assimilation (CDA) system, based on Ensemble Kalman Filter, was established. Both Kaplan sea surface temperature (SST) from January 1856 December 2018 and ECMWF twentieth century reanalysis (ERA-20C) wind 1900 February 2010 were assimilated for initialization. Second, (EP) system established using stochastic optimal perturbation that...

Abstract. In the data assimilation of coupled models, stongly (SCDA) is much more complicated than weakly (WCDA), since it involves cross-domain error covariances which could be very inaccurate when ensemble size small. this study, SCDA experiments are conducted using a two-scale Lorenz '96 model, system composed by two models in domains have different temporal and spatial scales. A localization strategy specially designed for adjustment Kalman filter (EAKF) used (CDA) experiments. The...

Temporal vertical eddy viscosity coefficient (VEVC) in an Ekman layer model is estimated using adjoint method. Twin experiments are carried out to investigate the influences of several factors on inversion results, and conclusions twin 1) method a capable estimate different kinds temporal distributions VEVCs; 2) gradient descent algorithm better than CONMIN L-BFGS for present problem, although posterior two algorithms perform convergence efficiency; 3) results sensitive initial guesses; 4)...

Adjoint method is used to assimilate pseudoobservations simultaneously estimate the OEVP and WSDC in an oceanic Ekman layer model. Five groups of experiments are designed investigate influences that optimization algorithms, step-length, inverse integral time adjoint model, prescribed vertical distribution eddy viscosity, regularization parameter exert on inversion results. Experimental results show best estimation obtained with GD algorithm; when step-length equal 1 Group 2; 3, 8 days yields...

Model error is an important source of uncertainty that significantly reduces the accuracy El Niño–Southern Oscillation (ENSO) prediction. In this study, ensemble coupled data assimilation was employed to estimate tendency fifth-generation Lamont–Doherty Earth observation (LDEO5) model, which represented comprehensive effect different sources errors. Then, estimated applied prediction system for ENSO Assimilation experiments showed estimation yielded better analysis than state only. With...

Abstract For coupled numerical models with different components (domains), there are two kinds of assimilation strategies applied for producing ocean analysis and initial condition predictions: the strongly data (SCDA) weakly (WCDA). The former needs to accurately estimate cross‐component error covariances, which is much challenging, especially when a small ensemble size's Kalman filter‐based algorithm used model has spatiotemporal scales. In this study, we propose new scheme adjustment...

Parameter estimation plays an important role in reducing model error and thus is of great significance to improve the simulation prediction capabilities model. However, due filtering divergence, parameter by ensemble-based filters still faces challenges. Previous studies have shown that a covariance inflation scheme could alleviate divergence problem increasing signal-to-noise ratio state-parameter covariance. In this study, we proposed new based on local ensemble transform Kalman filter...

Based on an isopycnic-coordinate internal tidal model with the adjoint method, three groups of ideal experiments are carried out in order to investigate estimation spatially varying bottom friction coefficients (BFCs). In group 1, five values distance between independent points (DIP) used invert BFCs distribution conical surface. Results show that can be inverted successfully point scheme and strategy a DIP 50′ yield best results. 2, interpolation radius (IR) IR 1.9 times results first two...

In this study, the time-varying wind stress drag coefficient in Ekman model was inverted by cubic spline interpolation scheme based on adjoint method. Twin experiments were carried out to investigate influences of several factors inversion results, and conclusions (1) distributions with good agreement prescribed coefficients, superior direct Cressman scheme; (2) more advantageous than even if there is moderate noise observations. The further validated practical where currents speed derived...

The isopycnic-coordinate internal tidal model with adjoint assimilation method is developed into a three-layer version. Two groups of ideal experiments are carried out in order to investigate the estimation spatially varying open boundary conditions (OBCs). In group 1, different independent point schemes (IPSs) used invert 6 kinds prescribed distributions OBCs. Results show that, after assimilation, cost functions and their gradient norms reduced by about 2 orders magnitude 1 magnitude,...

China's environmental situation is still grim, pressure continues to increase. The demand of protection work in the new era for high resolution remote sensing application will continue Environmental monitoring has multi factor, quantitative inversion and precision as features, environment department need use a wide spectrum data with spectral capability monitor total amount pollutants macro scale long time series. implementation earth observation project provides support improvement sensing....

Abstract. Coastal erosion occurring all over the world is a disastrous coastal geological phenomenon. It can be caused by many natural factors such as wind and waves. Hurricane Sandy made landfall on east coast of United States at end October 2012 severe damage to economy ecological environment. In this paper, we employ ground-based LiDAR which has higher spatial resolution observe change detection Fire Island, New York where place severely affected. The research showed that sediment...

A double-satellite passive positioning system is constructed based on the theory of space geometry, where two observation coordinate systems and a fundamental exist. In each system, there exists ray from satellite to aircraft. One difficulty lies in that these rays may not intersect due existence various errors. Under this situation, work assumes middle point common perpendicular between actual position Based coordinates aircraft can be determined. dynamic model with adjoint method developed...