Exploring the quantitative impact of short-term weather variability intensity (SWVI) on influenza incidence in Hubei Prov⁃ ince is of significant importance for conducting early risk warning and formulating prevention policies. Based on the influenza inci⁃ dence data and meteorological station observation, an index of SWVI has been built, which can measure the cumulative changes over a short-term in minimum temperature between two consecutive weeks. Based on the Distributed Lag Nonlinear Model (DLNM), the rela⁃ tion between SWVI index and influenza incidence risk was evaluated and a set of method for level classification of influenza incidence risk was developed. The results show that the intra-annual variation of number of Influenza-Like Illnesses (ILI) exhibited bimodal struc⁃ ture, with the first peak occurring in autumn and winter, and the second peak appearing in early summer months. The SWVI index also exhibited a bimodal distribution, but the peak occurring earlier than the peak of ILI. From November to March of the following year, SWVI index had a strong indicative significance for the change of ILI morbidity. In this period, when SWVI reaches 8.0 ℃, the cumula tive relative risk (RR) of ILI incidence at the same period and the next week was 1.16 (95% confidence interval: 1.087-1.250). In addition, SWVI index also had an indirect effect on the risk of ILI with a lag of 4-9 weeks, which was less affected than the immediate effect, but lasted longer. Using the percentile method and the relationship model between the SWVI index and the ILI incidence risk, a set of influenza risk early warning method was established. When the SWVI index was greater than or equal to 8.0 ℃, the influenza incidence reached high risk level

The El Niño-Southern Oscillation (ENSO) is the strongest signal of interannual change of short-term climate, and it has an important impact on global short-term climate change. Although ENSO occurs in the tropical Pacific region, its effects are felt world⁃wide. For example, during the El Niño event, the Panama region is prone to drought, which will have a significant impact on shipping on the Panama Canal. Recent reports show that the Panama Canal region has been affected by drought since the spring of 2023, resulting in an abnormally low water level in the canal and the worst blockage in nearly 8 years. In view of this extreme phenomenon, the standardized precipitation-evapotranspiration index (SPEI) is used to analyze the drought conditions in the Panama Canal region, and the

In order to seek a suitable irrigation water source in the Tao river irrigation area of Dingxi of Gansu Province, this study adopts a completely randomized treatment design and sets three irrigation water sources including local shallow underground water and the Tao river irrigation and their alternative irrigation, among the underground water irrigation as a control treatment, and the effects of different irrigation water sources on celery growth characteristics, water consumption, yield, water use efficiency and economic benefits are explored in semi-arid region. The results show that compared with underground water irrigation, the plant height of celery under the Tao river irrigation and alternative irrigation both underground water and the Tao river decreases by 6.07 cm and 3.33 cm, the stem thicknesses decrease by 1.22 mm and 0.78 mm, the soil water storage decrease by 1.27% and 1.98%, the yields of celery decrease by 15.08% and 1.57%, the water use efficiency decrease by 15.53% and 2.46%, and the irrigation water use efficiency decrease by 15.46% and 2.01%, respectively, while the total water consumption increase by 0.09% and 0.47%, and the net income of celery increase by 3.1% and 18.0%, respectively. The increase of celery yields is the most obvious under the underground water irrigation, but its water cost is the most expensive, so its economic benefit is lower. Although the celery yields and water use efficiency under the alternative irrigation are slightly lower than that under the underground water irrigation, the water cost reduced greatly, so the economic benefit is the highest. The water cost under the Tao river irrigation is low, but its economic benefit increase slightly due to all indexes of celery decreasing significantly (P<0.05). In summary, the alternative irrigation both underground water and the Tao river can be used as a feasible and effective irrigation mode to increase production and income of farmers in the Tao river irrigation area of Dingxi.

Atmospheric precipitation is the main source of soil moisture in the desert grassland in arid and semi-arid areas of Inner Mongolia and an important driving factor of various biological processes at different spatial and temporal scales. The study on the response process of soil moisture to precipitation has important theoretical value for regulating land cover, restoring vegetation scientifically and promoting the effective conversion of atmospheric precipitation to soil water. Based on daily precipitation during 2012-2020, hourly precipitation and soil moisture observation data of 0-50 cm layers from late April to late October during 2016-2020 at an automatical meteorological station in the desert grassland, the precipitation distribution pattern and the response process of soil moisture to independent precipitation events were analyzed. The results show that the precipitation events less than 5.0 mm were dominant, which belonged to typical precipitation pulsation event in arid and semi-arid areas. The precipitation thresholds of soil moisture response for 0-10 cm, >10-20 cm, >20-30 cm, >30-40 cm and >40-50 cm layer were 3.2, 9.2, 14.3, 16.7 and 25.3 mm, respectively. The probability of 0-10 cm soil moisture response caused by independent precipitation event of light rain was 36.0%, and the probability of moderate rain causing soil moisture response in 0-10 cm, >10-20 cm, >20-30 cm layer were 100%, 39.5% and 7.0%, respectively, while heavy rain and above could cause soil moisture response in all layers of 0-50 cm. With the increase of soil depth, the probability and degree of soil moisture response to precipitation in each layer showed a decreasing trend. Correlation analysis showed that there was a significant negative correlation between precipitation (or effective precipitation intensity) and soil moisture lag time in each layer of 0-40 cm, and there was an extremely significant positive correlation between precipitation and soil moisture increment in each layer. The relationship between precipitation and soil moisture increment of 0-20 cm layers was polynomial function, and that between precipitation and soil moisture increment of >20-50 cm layers was linear function.

Based on NOAA and NCEP reanalysis data and historical running output results from coupled model intercomparison project phase  5 models (CMIP5), the capability of those models in simulating the climatic field of the largescale environmental factors controlling typhoon intensity was evaluated firstly. Then, the capability of CMIP5 models in simulating the spatial distribution and temporal variation characteristics of the environmental factors was evaluated over the major regions of typhoon development. The results show that there were great differences in the climatic field and spatiotemporal changes of the largescale environmental factors in CMIP5 models. CESM1BGC, CESM1CAM5 and CNRMCM5 could well simulate the climate distribution and increasing characteristics of the observed sea surface temperature. CCSM4, CESM1BGC and CESM1CAM5 could well simulate the climate distribution and thickening characteristics of the observed ocean mixed layer thickness. ACCESS10, ACCESS13, CANESM2 and GFDLESM2M could well simulate the climate distribution and decreasing characteristics of the observed outflow layer temperature, but the simulated decreasing amplitude was small. Access10, CESM1CAM5, CNRMCM5, MPAESMMR and GFDLESM2M could well simulate the climate distribution and trend characteristics of the observed vertical wind shear. The comprehensive evaluation showed that CESM1BGC and CESM1CAM5 could be used to study the climate change of typhoon intensity in the northwest Pacific ocean.

Based on sea ice concentration data from Hadley Center of UK, the effects of autumn Arctic sea ice change on winter temperature in the middle and low reaches of the Yangtze River (MLRYR) had been analyzed through synthesis, correlation and other statistical methods. It was found that the variation of sea ice concentration in the north of the Laptev Sea and the east of East Siberian Sea could be used as a precursive signal to predict winter temperature in the MLRYR. When sea ice concentration in the north of the Laptev Sea and the east of East Siberian Sea was higher in autumn, the meridional gradient of two-meter temperature was bigger in winter in midland of the mid-high latitudes of Eurasia, and the blocking high in the Ural Mountain was weaker, there was mainly zonal circulation over the mid-high latitudes of Eurasia, and air temperature was higher in the MLRYR, and vice versa.