In order to increase the yield of antigen in rose bengal precipitation test of Brucellosis,experiments were made in the production.Anlysis and summary were also put forward at last.
Abstract In making weather and climate predictions, the goal is often not to predict the instantaneous, local value of temperature, wind speed, or rainfall; instead, the goal is often to predict these quantities after averaging in time and/or space-for example, over one day or one week. What is the impact of spatial and/or temporal averaging on forecasting skill?Here this question is investigated using simple stochastic models that can be solved exactly analytically. While the models are idealized, their exact solutions allow clear results that are not affected by errors from numerical simulations or from random sampling. As a model of time series of oscillatory weather fluctuations, the complex Ornstein-Uhlenbeck process is used. To furthermore investigate spatial averaging, the stochastic heat equation is used as an idealized spatiotemporal model for moisture and rainfall. Space averaging and time averaging are shown to have distinctly different impacts on prediction skill. Spatial averaging leads to improved forecast skill, in line with some forms of basic intuition. Time averaging, on the other hand, is more subtle: it may either increase or decrease forecast skill. The subtle effects of time averaging are seen to arise from the relative definitions of the time averaging window and the lead time. These results should help in understanding and comparing forecasts with different temporal and spatial averaging windows.
Assessing the relationships between ecosystem services supply and demand is crucial to support sustainable planning and human well-being. In the present study, we analyzed the ecosystem services supply and demand, synergies and trade-offs among services, as well as the spatial relationships between supply and demand, for four services in a desert steppe of Inner Mongolia. In terms of the balance between supply and demand, the grass production and carbon stock supply exceeded the demand, whereas the demand of water yield and windbreak and sand fixation services surpassed the supply. The degree of demand in windbreak and sand fixation service was met increased from 14.7% in 2000 to 20.6% in 2017, versus a decrease from 18.0% to 8.2% in water yield. The spatial distributions of the water yield and carbon stock demand were similar, and there was a significant synergy between them. The grass production supply and demand were not spatially matched, with higher supply in the eastern part of the study area and higher demand in the western part. Areas with high demand for the windbreak and sand fixation service also had a high supply. The water supply and demand in the low-coverage grassland were relatively balanced, and the deficiency of carbon stock supply was mainly found in construction land. In summary, for the sustainable development of animal husbandry and to reduce wind erosion, each county should establish an appropriate livestock density standard based on local constraints. Furthermore, it is also crucial for policymakers to develop water-saving industries to improve water utilization efficiency, and to set targets for CO2 emissions to reduce the impact on climate change.
The continental shelf and open sea region have different ocean physical and environmental responses to tropical cyclones (TC). The present study firstly compared the grid-based maximum response (GMR) of sea surface chlorophyll a (Chl-a) to TCs Wind Pump between the continental shelf (depths 50-200m) and open sea (depths>200 m) region in the South China Sea (SCS) during 1998-2020, using multiple-satellite data. For all TC events, the average Chl-a increases by 0.13 mg/m 3 . The comparisons between the pre- and post-TC periods show that Chl-a increases by 0.18 mg/m 3 (115%) in the continental shelf and 0.07 mg/m 3 (57%) in the open sea region, respectively. In both areas, TC-induced Chl-a enhancement (Chl_en) strongly depends on TC maximum wind speed and translation speed. The strong and fast-moving TCs and weak and slow-moving TCs both induce the maximum Chl_en in the continental shelf region. While in the open sea, the maximum Chl_en was induced by the strong and slow-moving TCs. Overall, our results reveal that the TC wind pump’s effects on Chl-a enhancement are stronger in the continental shelf region than in the open sea.
The goal of this study was to investigate the soil particle-size distribution (PSD) and pore structure characteristics in the Kubuqi Desert in order to provide basic data for gaining insights into the soil-modifying properties of the local vegetation. Based on laser diffraction analysis, we measured the soil PSD and calculated the single and multi-fractal dimensions of the soils under typical artificial forest and natural grassland vegetation. The diameters, volumes and surface areas of the soil pores were determined via nitrogen adsorption experiments. The relationships between the fractal characteristics and pore structure parameters of the soil were investigated via redundancy analysis and stepwise regression. The clay content was less than 2.0%, and the sand content was greater than 75.0%. There was variability in the PSD and fractal dimension, which was mainly observed for the 0–20 cm, 20–80 cm, and 80–100 cm soil layers. In the 0–80 cm, the fine particle content, single fractal dimension ( D ), entropy dimension ( D 1 ), ratio of D 1 to the capacity dimension ( D 1 /D 0 ), and correlation dimension ( D 2 ) were smaller for the forest soils than for the grassland soils. The fine particle (clay and silt) content of the 80–100 cm soil layer was approximately 37.8% higher for the Salix psammophila- 8a than for the Salix psammophila- 3a, and it was approximately 161.4% higher for the Populus popular- 35a than for the Pinus sylvestris var. mongolica- 8a. The silt content, D 1 , D 1 /D 0 , and D 2 were significantly positively correlated with the specific surface area ( SSA ), total pore volume ( TPV ), and average pore diameter ( APD ) of the nanopores ( p < 0.05, 0.01, or 0.001), and they were significantly negatively correlated with the percentage of the micropore volume ( PMV ) ( p < 0.05 or 0.01). In the Kubuqi Desert, the fine particle content and fractal dimensions of the soil layer below the root zone of shrub and arbor vegetation increased with increasing stand age, but the trend was reversed in the shallower soil layers. The variability of the soil PSD characteristics was strongly correlated with the variability of the nanopore parameters on the microscopic scale, suggesting that the total pore volume, average pore diameter, and percentage of the micropore volume may be potential indicators of the soil structure and quality.
Retrieving historical tropical cyclones (TC) which have similar position and hazard intensity to the objective TC is an important means in TC track forecast and TC disaster assessment. A new similarity retrieval scheme is put forward based on historical TC track data and ambient field data, including ERA-Interim reanalysis and GFS and EC-fine forecast. It takes account of both TC track similarity and ambient field similarity, and optimal weight combination is explored subsequently. Result shows that both the distance and direction errors of TC track forecast at 24-hour timescale follow an approximately U-shape distribution. They tend to be large when the weight assigned to track similarity is close to 0 or 1.0, while relatively small when track similarity weight is from 0.2∼0.7 for distance error and 0.3∼0.6 for direction error.
The heaviest rainfall in recent six decades fell in Beijing on 21 July 2012, reaching a record of 460 mm within 18 h. This rainfall was a typical remote precipitation event related to Typhoon Vicente (1208). Observational analysis indicates that Vicente influenced distant heavy rainfall by transporting water vapor northward to the Beijing area. This moisture transport was mainly driven by the interaction between Vicente and the western Pacific subtropical high (WPSH) associated with the formation of a low-level southeasterly moisture channel. A set of numerical sensitivity experiments were performed with prescribed typhoons of different intensities to investigate the interaction between Vicente and the WPSH and its effects on this rainstorm process. The results indicate that the WPSH interacting with typhoons of different intensities may exert varying degrees of influence on the development of a southeasterly moisture channel, resulting in a change in rain rate and location over the Beijing area. Specifically, in the presence of an enhanced typhoon, the WPSH shows remarkable withdrawal to the east, which is favorable for a northward extension of the southeasterly moisture channel, thereby increasing moisture supply for the rainstorm. The WPSH tends to stretch westward in a zonal pattern if the typhoon is weakened or removed, hindering the northward extension of the moisture channel. Thus, the rainfall area may be expected to expand or contract, with corresponding increases or decreases in rain rate over the Beijing area with a strengthened or weakened typhoon, respectively.
Abstract By interacting with radiation, clouds modulate the flow of energy through the Earth system, the circulation of the atmosphere, and regional climate. We review the impact of cloud‐radiation interactions for the atmospheric circulation in the present‐day climate, its internal variability and its response to climate change. After summarizing cloud‐controlling factors and cloud‐radiative effects, we clarify the scope and limits of the Clouds On‐Off Klimate Model Intercomparison Experiment (COOKIE) and cloud‐locking modeling methods. COOKIE showed that the presence of cloud‐radiative effects shapes the circulation in the present‐day climate in many important ways, including the width of the tropical rain belts and the position of the extratropical storm tracks. Cloud locking, in contrast, identified how clouds affect internal variability and the circulation response to global warming. This includes strong, but model‐dependent, shortwave and longwave cloud impacts on the El‐Nino Southern Oscillation, and the finding that most of the poleward circulation expansion in response to global warming can be attributed to radiative changes in clouds. We highlight the circulation impact of shortwave changes from low‐level clouds and longwave changes from rising high‐level clouds, and the contribution of these cloud changes to model differences in the circulation response to global warming. The review in particular draws attention to the role of cloud‐radiative heating within the atmosphere. We close by raising some open questions which, among others, concern the need for studying the cloud impact on regional scales and opportunities created by the next generation of global storm‐resolving models. This article is categorized under: Climate Models and Modeling > Knowledge Generation with Models
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)