摘要：The virtual globe is the default visualization for Digital Earth applications,but it can only show one half of the *** article introduces user-adjustable,on-the-fly projection of georeferenced raster images for web mapping and web GIS *** technique allows users to center a map on arbitrary locations,while still seeing the entire Earth *** web mapping libraries can apply map projection transformations to vector data in the browser,but they do not currently support the projection of raster images at interactive frame *** use the cross-platform WebGL(Web Graphics Library)graphics pipeline for hardware-accelerated projection of raster data in web *** algorithmic techniques–inverse per-fragment projection,and combined forward per-triangle and inverse per-fragment projection–for georeferenced raster imagery are *** resulting raster maps combine the ease of use and flexibility of interactive virtual globes with the ability to show the entire *** adjustable projection of raster imagery allows users to observe global phenomena that are difficult to visualize on virtual globes or traditional maps with static projections.

摘要：The Weather Research and Forecasting （WRF） model is used in a regional climate model configuration to simulate past precipitation climate of China during the rainy season （May-September） of 1981-2000, and to investigate potential future （2041-2060 and 2081-2100） changes in precipitation over China relative to the reference period 1981-2000. WRF is run with initial conditions from a coupled general circulation model, i.e., the high-resolution version of MIROC （Model for Interdisciplinary Research on Climate）. WRF reproduces the observed distribution of rainy season precipitation in 1981-2000 and its interannual variations better than MIROC. MIROC projects increases in rainy season precipitation over most parts of China and decreases of more than 25 mm over parts of Taiwan and central Tibet by the mid-21st century. WRF projects decreases in rainfall over southern Tibetan Plateau, Southwest China, and northwestern part of Northeast China, and increases in rainfall by more than 100 mm along the southeastern margin of the Tibetan Plateau and over the lower reaches of the Yangtze River during 2041-2060. MIROC projects further increases in rainfall over most of China by the end of the 21st century, although simulated rainfall decreases by more than 25 mm over parts of Taiwan, Guangxi, Guizhou, and central Tibet. WRF projects increased rainfall of more than 100 mm along the southeastern margin of the Tibetan Plateau and over the lower reaches of the Yangtze River and decreased rainfall over Southwest China, and southern Tibetan Plateau by the end of the 21st century.

摘要：In the Lancang‒Mekong River basin(LMRB),agriculture,dominating the local economy,faces increasing challenges in water supply under climate *** projection of future precipitation in this basin is essential for understanding the *** this study,the Weather Research and Forecasting(WRF)model was applied to project the LMRB *** with the historical period(1986e2005),we analyzed the changes of both the projected precipitation amount and the frequency of rainless(100 mm d
1)for three periods,namely the near-term(2016e2035),mid-term(2046e2065),and long-term(2080e2099).The results indicate that the precipitation amount during the wet season(AprileOctober)is expected to increase in most areas of the basin for the three *** for the precipitation during the dry season(NovembereMarch),an increase is projected in most areas for the near-term,while an increase in the lower reach of the basin and a decrease in the upper and middle reach for the mid-term and *** precipitation reduction is expected to be greatest in Myanmar,Laos,Thailand,and Yunnan province of China for the *** frequency of precipitation in different intensities has prominent regional and temporal *** the wet season,the days of rainless and light rain are expected to decrease in the middle reach,whereas the days of rainstorm and heavy rainstorm *** feature is especially strong in southern Thailand,southern Laos and Cambodia in the near-term and in Laos and Thailand for the mid-term and *** the dry season,there are projected increasing rainless days and decreasing days of precipitation for the other intensities in the middle reach,and opposite in the rest area of the *** projected precipitation changes have potential various impact in different parts of the *** middle re

摘要：Conditional nonlinear optimal perturbation(CNOP) is an extension of the linear singular vector technique in the nonlinear *** represents the initial perturbation that is subjected to a given physical constraint,and results in the largest nonlinear evolution at the prediction ***-type errors play an important role in the predictability of weather and ***,when calculating CNOP in a complicated numerical model,we need the gradient of the objective function with respect to the initial perturbations to provide the descent direction for searching the phase *** adjoint technique is widely used to calculate the gradient of the objective ***,it is difficult and cumbersome to construct the adjoint model of a complicated numerical model,which imposes a limitation on the application of *** on previous research,this study proposes a new ensemble projection algorithm based on singular vector decomposition(SVD).The new algorithm avoids the localization procedure of previous ensemble projection algorithms,and overcomes the uncertainty caused by choosing the localization radius *** new algorithm is applied to calculate the CNOP in an intermediate forecasting *** results show that the CNOP obtained by the new ensemble-based algorithm can effectively approximate that calculated by the adjoint algorithm,and retains the general spatial characteristics of the ***,the new SVD-based ensemble projection algorithm proposed in this study is an effective method of approximating the CNOP.

摘要：The North China Plain often su ers heavy haze pollution events in the cold season due to the rapid industrial development and urbanization in recent *** the winter of 2015,the megacity cluster of Beijing Tianjin Hebei experienced a seven-day extreme haze pollution episode with peak PM2.5(particulate matter(PM)with an aerodynamic diameter≤2.5μm)concentration of 727μg m *** the in uence of meteorological conditions on pollu-tant evolution,the e ects of varying initial conditions and lateral boundary conditions(LBCs)of the WRF-Chem model on PM2.5 concentration variation were investigated through ensemble methods.A control run(CTRL)and three groups of ensemble experiments(INDE,BDDE,INBDDE)were carried out based on difierent initial conditions and LBCs derived from ERA5 reanalysis data and its 10 ensemble *** CTRL run reproduced the meteorological conditions and the overall life cycle of the haze event reasonably well,but failed to capture the intense oscillation of the instantaneous PM2.5 ***,the ensemble forecasting showed a considerable advantage to some *** with the CTRL run,the root-mean-square error(RMSE)of PM2.5 concentration decreased by 4.33%,6.91%,and 8.44%in INDE,BDDE and INBDDE,respectively,and the RMSE decreases of wind direction(5.19%,8.89%and 9.61%)were the dominant reason for the improvement of PM2.5 concentration in the three ensemble *** on this case,the ensemble scheme seems an e ective method to improve the prediction skill of wind direction and PM2.5 concentration by using the WRF-Chem model.

摘要：This paper extends the dimension-reduced projection four-dimensional variational assimilation method(DRP-4DVar) by adding a nonlinear correction process,thereby forming the DRP-4DVar with a nonlinear correction, which shall hereafter be referred to as the NC-DRP-4DVar. A preliminary test is conducted using the Lorenz-96 model in one single-window experiment and several multiple-window experiments. The results of the single-window experiment show that compared with the adjoint-based traditional 4DVar, the final convergence of the cost function for the NC-DRP-4DVar is almost the same as that using the traditional 4DVar, but with much less computation. Furthermore, the 30-window assimilation experiments demonstrate that the NC-DRP-4DVar can alleviate the linearity approximation error and reduce the root mean square error significantly.

摘要：Future climate change is usually projected by coupled earth system models under specific emission sce- narios designed by integrated assessment models （IAMs）, and this offline approach means there is no interaction between the coupled earth system models and the IAMs. This paper introduces a new method to design possible future emission scenarios and corresponding climate change, in which a simple economic and climate damage component is added to the coupled earth system model of Beijing Normal University （BNU-ESM）. With the growth of population and technological expertise and the declining emission-to-output ratio described in the Dynamic Inte- grated Climate-Economy model, the projected carbon emission is 13.7 Gt C, resulting in a 2.4℃ warming by the end of the twenty-first century （2080-2099） compared with 1980-1999. This paper also suggests the importance of the land and ocean carbon cycle in determining the CO2 con- centration in the atmosphere. It is hoped that in the near future the next generation of coupled earth system models that include both the natural system and the social dimension will be developed.

摘要：Oceanic observation design is of considerable significance and has made remarkable progress during the past several *** study addresses the critical role of numerical modeling in oceanic observation *** a brief introduction of the characteristics of existing oceanic observation design studies,we present the advantages of the model-based observation design strategy and further review its decisive *** demonstrate the effectiveness of this strategy,the targeted observation applications using the conditional nonlinear optimal perturbation(CNOP)approach for improving the Kuroshio predictions are ***,the authors present their consideration for correcting model errors by targeted observations of sensitive model parameters and mitigating the model-dependency problem by utilizing multiple modeling *** on using observing system simulation experiments to validate the designed observations and extending the model-based observation design strategy into observing oceanic climatological mean states are also discussed.

摘要：A regional climate model(RegCM4)is used to project climate change over China in the twenty-first century under the RCP4.5 and RCP8.5 *** driving GCM is CSIRO Mk3.6.0(hereafter referred to simply as CSIRO),and the simulation(hereafter referred to as CdR)is run at a grid spacing of 25 *** focus of the present paper is on the changes in mean surface air temperature and precipitation in December–January–February(DJF)and June–July–August(JJA)over *** of the model performances is provided first,followed by a comparison of future changes projected by CSIRO and *** warming in the future is simulated by both models,being more pronounced in DJF compared to JJA,and under RCP8.5 compared to *** warming shows different spatial patterns and,to a less extent,magnitude between CSIRO and *** change shows a general increase in DJF and a mixture of increase and decrease in *** differences between the two models are found in for precipitation change in *** paper further emphasizes the uncertainties in climate change projection over the region.

摘要：Using statistically downscaled atmospheric forcing, we performed a numerical investigation to evaluate future climate's impact on storm surges along the Gulf of Mexico and U.S. east coast. The focus is on the impact of climatic changes in wind pattern and surface pressure while neglecting sea level rise and other factors. We adapted the regional ocean model system(ROMS) to the study region with a mesh grid size of 7–10 km in horizontal and 18 vertical layers. The model was validated by a hindcast of the coastal sea levels in the winter of 2008. Model's robustness was confirmed by the good agreement between model-simulated and observed sea levels at 37 tidal gages. Two 10-year forecasts, one for the IPCC Pre-Industry(PI) and the other for the A1 FI scenario, were conducted. The differences in model-simulated surge heights under the two climate scenarios were analyzed. We identified three types of responses in extreme surge heights to future climate: a clear decrease in Middle Atlantic Bight, an increase in the western Gulf of Mexico, and non-significant response for the remaining area. Such spatial pattern is also consistent with previous projections of sea surface winds and ocean wave heights.