Abstract. The dust cycle is an important element of the Earth system, and further understanding of the main drivers of dust emission, transport, and deposition is necessary. The El NiñoâSouthern Oscillation (ENSO) is the main source of interannual climate variability and is likely to influence the dust cycle on a global scale. However, the causal influences of ENSO on dust activities across the globe remain unclear. Here we investigate the response of dust activities to ENSO using output from Coupled Modeling Intercomparison Project Phase 6 (CMIP6) historical simulations during the 1850â2014 period. The analyses consider the confounding impacts of the Southern Annular Mode, the Indian Ocean Dipole, and the North Atlantic Oscillation. Our results show that ENSO is an important driver of dry and wet dust deposition over the Pacific, Indian, and Southern oceans and parts of the Atlantic Ocean during 1850â2014. Over continents, ENSO signature is found in America, Australia, parts of Asia, and Africa. Further, ENSO displays significant impacts on dust aerosol optical depth over oceans, implying the controls of ENSO on the transport of atmospheric dust. Nevertheless, the results indicate that ENSO is unlikely to exhibit causal impacts on regional dust emissions of major dust sources. While we find high consensus across CMIP6 models in simulating the impacts of ENSO on dust deposition and transport, there is little agreement between models for the ENSO causal impacts on dust emission. Overall, the results emphasize the important role of ENSO in global dust activities.
Abstract The El Niño-Southern Oscillation (ENSO) is a major mode of interannual climate variability and is expected to affect runoff variations at a global scale. While previous studies focused on the correlation analysis between ENSO and runoff and ENSO-induced amplitude changes of runoff, causal analysis considering the confounding impacts of other major climate modes is lacking. As more extreme ENSO events are projected in the future, it is crucial to enhance our understanding of the impacts of ENSO on global runoff. Here we examine the causal influences of ENSO on runoff over the future period 2015–2100 using outputs from Coupled Modeling Intercomparison Project Phase 6 model simulations. Our analyses account for the possible confounding effects of the Southern Annular Mode, the North Atlantic Oscillation and the Indian Ocean Dipole. We find that the signature of ENSO is detectable in future total runoff over various regions including limited areas in central and eastern Asia, large parts of Southeast Asia, limited areas in the eastern and southern Africa, western and eastern Australia, parts of southern and western North America, eastern Antarctica and large parts of South America. There is a high agreement across models for the causal influences of ENSO over central Asia, the eastern coast of Australia, southcentral North America and South America. Multi-model future projections demonstrate higher impacts of ENSO on total runoff over western and central Asia, the western coast of North America and southeastern South America compared to the historical period 1915–2000. All regions with substantial ENSO impacts account for 3.6% land-area in historical simulation and this fraction increases to 5.6% in the future scenario. In addition, the results underscore that surface runoff is less sensitive to ENSO compared to total runoff in most regions. These results may have implications for future water management planning based on ENSO.
Abstract Here we examine the causal effects of El Niño–Southern Oscillation (ENSO) on the global carbon cycle over historical and future periods utilizing datasets from the Coupled Modeling Intercomparison Project Phase 6 models. Our results show that ENSO exhibits impact on terrestrial carbon fluxes and carbon storage over numerous regions of Asia, Oceania, and America. High consensus is found between models for the influences of ENSO over these regions. The results demonstrate that the effects of ENSO on carbon cycling over subtropics and high‐latitude regions may be more significant than previously understood. In historical simulation, the regions affected by ENSO account for approximately 8.5% land‐area and this proportion rises to approximately 11.7% in the future simulation, indicating an increase in ENSO influences on the gross primary productivity of terrestrial ecosystems. In addition, the results emphasize stronger response of seasonal carbon stocks to ENSO compared to that of seasonal carbon fluxes.
Abstract Central Asia (CA) is a region at risk of drought and desertification under a warming environment. Hence, further understanding of the drivers of CA hydroclimate is crucial for the production, ecological environment, and social security of this region. However, little is known about the impacts of the El Niño–Southern Oscillation (ENSO), a major mode of global climate variability, on future CA hydroclimate. Here we investigated the causal influence of ENSO on future CA hydroclimate using outputs from Coupled Modeling Intercomparison Project Phase 6 (CMIP6) models. We find significant causal effects of ENSO on precipitation, evaporation, soil moisture, and runoff over a large part of CA in the model simulations. ENSO is related to the restructuring of winds and atmospheric moisture sources over the tropical Indian Ocean, the Red Sea, and the CA, and thus directly influenced the CA hydroclimate. We showed that, compared to other major climate modes, ENSO exhibits a dominant effect on CA hydroclimate. Model projections indicate that future CA hydroclimate is likely to be linked to ENSO variations with high consistency between models and the likelihood of the hydroclimatic impacts of ENSO on CA may increase in the 21st century. This increase is associated with the extension of ENSO-driven moisture transport over southern and western CA. These findings underscore that ENSO may complicate the future hydroclimatic systems over CA.
Abstract. The dust cycle is an important element of the Earth system, and further understanding of the main drivers of dust emission, transport, and deposition is necessary. The El Niño–Southern Oscillation (ENSO) is the main source of interannual climate variability and is likely to influence the dust cycle on a global scale. However, the causal influences of ENSO on dust activities across the globe remain unclear. Here we investigate the response of dust activities to ENSO using output from Coupled Modeling Intercomparison Project Phase 6 (CMIP6) historical simulations during the 1850–2014 period. The analyses consider the confounding impacts of the Southern Annular Mode, the Indian Ocean Dipole, and the North Atlantic Oscillation. Our results show that ENSO is an important driver of dry and wet dust deposition over the Pacific, Indian, and Southern oceans and parts of the Atlantic Ocean during 1850–2014. Over continents, ENSO signature is found in America, Australia, parts of Asia, and Africa. Further, ENSO displays significant impacts on dust aerosol optical depth over oceans, implying the controls of ENSO on the transport of atmospheric dust. Nevertheless, the results indicate that ENSO is unlikely to exhibit causal impacts on regional dust emissions of major dust sources. While we find high consensus across CMIP6 models in simulating the impacts of ENSO on dust deposition and transport, there is little agreement between models for the ENSO causal impacts on dust emission. Overall, the results emphasize the important role of ENSO in global dust activities.
We present a sparse coding-based framework for motion style decomposition and synthesis. Dynamic Time Warping is firstly used to synchronized input motions in the time domain as a pre-processing step. A sparse coding-based decomposition has been proposed, we also introduce the idea of core component and basic motion. Decomposed motions are then combined, transfer to synthesize new motions. Lastly, we develop limb length constraint as a post-processing step to remove distortion skeletons. Our framework has the advantage of less time-consuming, no manual alignment and large dataset requirement. As a result, our experiments show smooth and natural synthesized motion.
In the context of online Robust Principal Component Analysis (RPCA) for the video foreground-background separation, we propose a compressive online RPCA with optical flow that separates recursively a sequence of frames into sparse (foreground) and low-rank (background) components. Our method considers a small set of measurements taken per data vector (frame), which is different from conventional batch RPCA, processing all the data directly. The proposed method also incorporates multiple prior information, namely previous foreground and background frames, to improve the separation and then updates the prior information for the next frame. Moreover, the foreground prior frames are improved by estimating motions between the previous foreground frames using optical flow and compensating the motions to achieve higher quality foreground priors. The proposed method is applied to online video foreground and background separation from compressive measurements. The visual and quantitative results show that our method outperforms the existing methods.
Abstract. Ozone in the troposphere is a greenhouse gas and a pollutant, hence, additional understanding of the drivers of tropospheric ozone evolution is essential. The El Niño–Southern Oscillation (ENSO) is a main climate mode and may contribute to the variations of tropospheric ozone. Nevertheless, there is uncertainty regarding the causal influences of ENSO on tropospheric ozone under warming environment. Here, we investigated the links between ENSO and tropospheric ozone using Coupled Modeling Intercomparison Project Phase 6 (CMIP6) data over the period 1850–2014. Our results show that ENSO impacts on tropospheric ozone are primarily found over oceans, while the signature of ENSO over continents is largely nonsignificant. The response of ozone to ENSO may vary depending on specific air pressure levels in the troposphere. These responses are weak in the middle troposphere and are stronger in the upper and lower troposphere. Although there are biases in simulating the signature of ENSO on surface ozone, these signatures in the middle and upper troposphere appear to be more consistent across CMIP6 models. While the response of tropical tropospheric ozone to ENSO is in agreement with previous works, our results suggest that ENSO impacts on tropospheric ozone of the mid-latitude regions over the southern Pacific, Atlantic, and Indian oceans might be more significant than previously understood.
