Yong-Ping Wu

Effects of time delay and space on herbivore dynamics: linking inducible defenses of plants to herbivore outbreak.

Empirical results indicate that inducible defenses of plants have effects on herbivore populations. However, little is known about how inducible defenses of plants have influences on herbivore outbreak when space effect is considered. To reveal the relationship between inducible defenses and herbivore outbreak, we present a mathematical model to describe the interaction of them. It was found that time delay plays dual effects in the persistence of herbivore populations: (i) large value of time delay may be associated with small density of herbivore populations, and thus causes the populations to run a higher risk of extinction; (ii) moderate value of time delay is beneficial for maintaining herbivore density in a determined range which may promote the persistence of herbivore populations. Additionally, we revealed that interaction of time delay and space promotes the growth of average density of herbivore populations during their outbreak period which implied that time delay may drive the resilience of herbivore populations. Our findings highlight the close relationship between inducible defenses of plants and herbivore outbreak.

Interactions of Multiple Atmospheric Circulation Drive the Drought in Tarim River Basin.

Global warming is likely to cause overall drying of land surfaces and aridity increasing leading to expansion of dry climate zones. There is an increased risk of extremely arid environment and large deserts developed progressively in the central Asia. However, the key factors causing the drying in mid-Asia remain inconclusive. Here, we analyzed the relationship among precipitation, water vapor transportation in Tarim River Basin (TRB) and Multiple Atmospheric Circulation (MAC) to explore the mechanism of MAC driving the drying in TRB, through comparing MAC between abundant and scarce precipitation years. We found that Westerly Circulation (WC) and Asian Summer Monsoon (ASM) are likely to promote the precipitation respectively. Whereas, they not only have their own influence but also restrict each other and facilitate the forming of peculiar water vapor transport channel for TRB, which is probably to restrain the precipitation and its distribution pattern and accelerate the drying in this region. Our results enrich the findings on mechanisms of wet places becoming wetter while dry areas getting drier under the global warming.

A new algorithm for seasonal precipitation forecast based on global atmospheric hydrological water budget

Precipitation forecast has been identified as one of the central issues in climate research. However, the underlying mechanisms of precipitation are far from being understood. In this paper, a new algorithm of forecasting precipitation based on law of conservation of mass in hydrological cycle is proposed and its feasibility is verified. The algorithm mainly include three steps: in the first step, the area we employ is divided into a number of sub-areas, the precipitation source and evaporation whereabouts equations for sub-regions are established, and the rationality of them can be verified by checking whether the precipitation source and evaporation equations meet a self-consistent relationship or not; in the second step, a conversion equation for sub-regional precipitation prediction will be established, which characterize the relationship between precipitation and evaporation in the sub-areas; in the last step, if the regional evaporation, precipitation and moisture divergence (convergence) function keep stable in a certain time scale, then precipitation forecast is achieved by evaporation anomalies and moisture divergence function, which can be predicted according to the prophase sea surface temperature and atmospheric circulation. Finally, the northern and southern hemispheres seasonal precipitation, evaporation and moisture divergence (convergence) weighting coefficients are calculated using this algorithm based on European centre for medium-range weather forecasts (ECMWF) interim re-analysis (ERA-Interim) dataset, which well verifies the feasibility of the algorithm. The obtained results may provide new insights for precipitation forecast in the future.

Signal of Acceleration and Physical Mechanism of Water Cycle in Xinjiang, China

Global warming accelerates water cycle with features of regional difference. However, little is known about the physical mechanism behind the phenomenon. To reveal the links between water cycle and climatic environment, we analyzed the changes of water cycle elements and their relationships with climatic and environmental factors. We found that when global warming was significant during the period of 1986-2003, the precipitation in Tarim mountains as well as Xinjiang increased rapidly except for Tarim plains, which indicated that there existed a signal of acceleration for water cycle in Xinjiang. The speed of water cycle is mainly affected by altitude, latitude, longitude, slope direction, and the most fundamental element is temperature. Moreover, according to Clausius-Kela Bai Lung relation, we found that the climate change induced the increase of temperature and accelerated the local water cycle only for the wet places. Our results provide a possible physical mechanisms of water cycle and thus well link the climate change to water circulation.

Prospective Study on Applications of Non-Equilibrium Thermodynamics to Climate Modeling

ABSTRACT Wu, Y.; Cao, H., and Feng, G., 2015. Prospective study on applications of non-equilibrium thermodynamics to climate modeling. While focusing on the ability of climate models, this paper demonstrates the role and status of atmospheric dynamics and thermodynamics in building and developing climate models. Possible reasons for the insufficiency in climate models are analyzed, and the significance of non-equilibrium thermodynamics in further development of climate models, especially of regional climate models, is put forward. Besides, in non-equilibrium thermodynamics, the second law of thermodynamics indicates that, in an isolated system, irreversible process develops along the direction of increasing entropy whatever status the system is at the beginning, while the minimum entropy production principle states that non-equilibrium open system grows toward the status with minimum entropy production, which can be used as the development criterion for the non-equilibrium open system. As the typical open non-equilibrium system, atmospheric system undoubtedly follows some of the theorems of non-equilibrium thermodynamics. Therefore, the non-equilibrium thermodynamics theory has broad applicational prospects in climate modeling and prediction.

Characterizations of Water Vapor Flux and Precipitation over Arid Region under Climate Change

In this paper the variations and distributions of water vapor transportation and precipitation in typical arid region, Tarim River Basin (TRB), were analyzed and the relationship between them was discussed, using daily precipitation data of 26 weather stations in TRB and NCEP/NCAR monthly mean reanalysis data (2.5°×2.5°). The results show that a) the special distribution of precipitation and water vapor flux appear seasonal features, but is not consistent with each other for the multi-joint action of large-scale atmospheric circulation, topography around TRB, and b) the effects of water vapor flux on precipitation are different in sub-regions with different height and slop direction.

Effects of changes in vegetation on precipitation in the northern Tianshan Mountains evaluated using multiple time scales

This study used a combination of the wavelet cross-correlation technique and numerical analysis of vegetative feedback to study the role of climate–vegetation feedback from 1981 to 2009 in the northern Tianshan Mountains, Xinjiang Province, China. The study area included the Irtysh River, the Bortala and Ili River valleys, the northern slopes of the Tianshan Mountains, and the western Junggar Basin. The feedback effects of changes in vegetation on precipitation appeared to vary in these five regions when different time scales are used to examine them. The most useful time scale was generally found to be 4–6 months. Time lag was another characteristic of this process, and the optimal time lag was 3–4 months. Nevertheless, optimal time scale and time lag did not differ significantly in these five regions. In this way, the correct time scale of the effects of variations in vegetation on precipitation in this cold, arid area was found. This time scale and time lag can be assessed through wavelet cross-correlation analysis. Then numerical analysis can be used to improve the accuracy of the analysis.

Impacts of Climate Change on Biological Dynamics

1Complex Systems Research Center, Shanxi University, Taiyuan, Shanxi 030006, China 2Department of Mathematics and Physics, Anyang Institute of Technology, Anyang 455000, China 3Department of Mathematics and Statistics, University of Victoria, Victoria, BC, Canada V8W 3R4 4Department of Mathematics, Southeast University, Nanjing 210096, China 5Ecological Complexity and Modeling Laboratory, University of California, Riverside, CA 92521-0124, USA 6Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Fukuoka 816-8580, Japan 7College of Physics Science and Technology, Yangzhou University, Yangzhou, Jiangsu 225002, China 8Department of Botany and Plant Sciences, University of California, Riverside, CA 92521-0124, USA

Spatiotemporal evolution characteristics of precipitation in Tarim River Basin during 1960–2009

Using U.S. NCEP / NCAR monthly mean reanalysis data (2.5°×2.5°) and daily precipitation data at 26 weather stations in Tarim River Basin from 1960 to 2009, spatiotemporal evolution characteristics of precipitation over Tarim River Basin (TRB) were analyzed. The results show that: 1) The spatial distribution of precipitation in TRB was in contrast with that in China, showing a gradual increase trend from southeast to northwest with some variation in different seasons and the year with more (less) rainfall; 2)The annual change in precipitation over mountains, plains and five sub-regions were likely consistent, and the decadal mutation of precipitation in around 1987 and 2003 appeared at almost all regions; 3)During the period of 1978 to 2003 in which global warming was the most significant, precipitation over mountain showed an clear increasing trend, while the precipitation over plain showed decreasing trend. It can be believed that the complexity of spatiotemporal distribution of precipitation over TRB implied a variety of precipitation mechanisms in this area, and the warm and wet evidence in western Tianshan Mountains may be the signal that global warming is accelerating the local water cycle.