Total Rainy Days Research Articles

Construction of a comprehensive meteorological risk index for wheat Fusarium head blight prediction based on more than a half-century of monitoring data.

Fusarium head blight (FHB) represents a critical threat to wheat production globally, not only reducing yields but also contaminating crops with harmful mycotoxins. This study aimed to elucidate new spatiotemporal patterns of FHB incidence and to develop a comprehensive meteorological risk index to enhance scientific prevention and control of the disease. Through the analysis of annual and decadal variations from 1965 to 2023, the study assessed FHB trends across four agricultural regions (I, II, III, and IV) in Jiangsu Province, located in the middle and lower reaches of the Yangtze River-a hotspot for FHB in China. Key findings include: Since 1965, Regions I and III consistently exhibited higher FHB incidence rates compared to Regions II and IV. Post-2000, there was a notable increase in years with high incidence rates, with Region III overtaking Region I as the region with the highest incidence. Since 2010, occurrences of FHB reaching the most severe grade (Grade 5) have surpassed those in previous decades across all regions. The study also revealed a stronger correlation between meteorological factors (cumulative precipitation, number of days with rainfall ≥ 0.1 mm, total rainy days with ≥ 2 and ≥3 consecutive days of rain, total rainy days with both average daily air temperature ≥ 15 °C and daily rainfall ≥ 0.1 mm, days with average daily relative humidity ≥ 85%, cumulative sunshine hours, and cumulative cloudy days) and the FHB incidence rates during the heading-flowering-grain filling period in Regions I, II, and III, compared to the heading-flowering period alone. This indicates that optimal temperature and high humidity during the grain filling stage significantly contribute to the final FHB incidence rates. Despite the less apparent correlation between temperature changes and disease rates, the significant warming trend observed since 2000 has likely fostered conditions conducive to the proliferation of FHB. The comprehensive meteorological risk index, constructed to incorporate key meteorological factors during the heading-flowering-filling period, showed a strong correlation with actual disease incidences. The index demonstrated fitting accuracy rates of 84.7% for Region I, 72.9% for Region II, 83.1% for Region III, and 90.9% for Region IV, underscoring its effectiveness in predicting FHB occurrences. This tool offers both convenience and practicality, providing valuable insights for strategically managing FHB risks based on local weather conditions.

The declining cyanobacterial blooms in Lake Taihu (China) in 2021: The interplay of nutrients and meteorological determinants

The cyanobacterial blooms are global environmental perils and have been extensively compounded and changeable in Lake Taihu with emerging significantly higher intensities during 2016–2019 than those in 2010–2015. However, the cyanobacterial density and chlorophyll-a (chl-a) contents of Lake Taihu in 2021 have been downturned in recent years, and the underlying mechanisms have become a heated subject in multiple aspects. Based on the monthly occurrence of cyanobacterial blooms at 31 monitoring stations in Lake Taihu from 2010 to 2021, combined with the data of environmental conditions such as water quality, pollutants load into the lake, and hydrometeorological factors, this study seeks to unravel the characteristics of cyanobacterial blooms in Lake Taihu in 2021, the shifting kinetics of the environmental factors, and discusses the intrinsic causes of the lower cyanobacterial bloom intensity in 2021. The results revealed that the wind speed in Lake Taihu remained stable in 2021, with an average rise of 0.5 °C in the ambient temperature. Similarly, the rainfall incidence and the total rainy days from July to August were 1.6 and 1.2 times of the average value from 2010 to 2020 respectively. Among the critical nutrients, a respective decline of 49 %, 56 %, and 78 % was recorded for the total nitrogen (TN), ammonia nitrogen (NH4+-N), and nitrate nitrogen (NO3–-N). Moreover, the random forest results evidenced that the NO3–-N, and NH4+-N were the key factors to affect the cyanobacterial density. This reduction in the nutrient levels caused by the abated nutrient loading into the lake coupled with the disproportionate rainfall and rainy days were the central causes for the obvious drop in the intensity of cyanobacterial blooms. Henceforth, the present work advocates to accelerate the robust technological application and management measures such as dual control of pollutant concentration and total amount to further reduce the nitrogen and phosphorus load to Lake Taihu.

Trend analysis of total rainfall events with light and heavy intensity for the 1976 – 2019 periode in Majene District – West Sulawesi

The increase of rain events due to climate change can affect local activities in several sectors such as agriculture, trade, infrastructure, etc, so climate information is importantly considered for operational sustainability. Therefore, this research is conducted to determine trend of changes in total rainy days and tendency of rain which refers to light rain <5 mm/day and heavy >30 mm/day every month in Majene based on Majene Meteorological Station data during 1976 – 2019 using linear regression method. Besides this research aims to provide information to related parties to consider policies as anticipatory and mitigating steps for natural phenomena to achieve effective activities. Results of analysis indicated a tendency of increasing trend in total of rainy days, the number of light and heavy rainy days in certain months. Based on rain posts, the increasing number of rainy days is dominantly followed by light rain events. This study informs that climate change has occurred in Majene, namely the increasing number of light rainy days. The information in this study can be used as knowledge to readers and consideration in certain policies, that the light rain happens a lot, but it cannot be denied that heavy rain will occur at any time unexpectedly.

The spatial pattern of selected extreme precipitation indices for Turkey (1975-2012)

Abstract This paper analyses extreme precipitation characteristics of Turkey based on selected WMO climate change indices. The indices – monthly total rainy days (RDays); monthly maximum 1-day precipitation (Rx1day); simple precipitation intensity index (SDII); and monthly count of days when total precipitation (represented by PRCP) exceeds 10 mm (R10mm) – were calculated for 98 stations for the 38-year overlapping period (1975–2012). Cluster analysis was applied to evaluate the spatial characterisation of the annual precipitation extremes. Four extreme precipitation clusters were detected. Cluster 1 corresponds spatially to Central and Eastern Anatolia and is identified with the lowest values of the indices, except rainy days. Cluster 2 is concentrated mainly on the west and south of Anatolia, and especially the coastal zone, and can be characterised with the lowest rainy days, and high and moderate values of other indices. These two clusters are the most prominent classes throughout the country, and include a total of 82 stations. Cluster 3 is clearly located in the Black Sea coastal zone in the north, and has high and moderate index values. Two stations on the north-east coast of the Black Sea region are identified as Cluster 4, which exhibits the highest values among all indices. The overall results reveal that winter months and October have the highest proportion of precipitation extremes in Turkey. The north-east part of the Black Sea region and Mediterranean coastal area from the south-west to the south-east are prone to frequent extreme precipitation events.

Evaluation of The Number of Rainy Days Observed for Long Years Due to Global Climate Change in Nevşehir /Turkey

In this research caried out Nevsehir province, Avanos and Ürgüp districts of Turkey's Central Anatolia Nevsehir. In the study, it is aimed to reveal the trends of years by changing the number of long year total rainy days by Mann Kendall and Sperman's Rho correlation tests. Within the scope of the study, 34 years long total monthly rainy days data between 1986-2019, which were obtained from automatic meteorology stations, were evaluated. According to the results of the trend analysis, the average total number of rainy days in Nevşehir province was 77 days minimum, the maximum number of rainy days was 142 days, and the average of the average number of rainy days was 109 days. In Avanos district, the average number of rainy days for a long time was 57 days, and the maximum number of rainy days was 129 days, while the average of the number of rainy days for long years was 89 days. In Ürgüp district, the average number of rainy days for a long time was 65 days, the maximum number of rainy days was 129 days, and the average of the number of rainy days for long years was 95 days. As a result, considering the number of long year rainy days, it is concluded that there is no significant trend in Nevşehir province, Avanos and Ürgüp district stations.

The relationship between raining and GPS – precipitable water vapor

Precipitable water vapor (PWV) can be retrieved from the delayed of the propagating GPS signal through the wet atmosphere. In the experiment, the GPS data in 2009 from the permanent GPS station name of CUSV were used to estimate the amount of integrated vertical water vapor above the GPS station in term of PWV. The results showed that the PWV were fluctuated all year long with their averaged of 31.05 mm. At the beginning of the year, the PWV were slightly increased until reach a plateau around DOY 120. This plateau was higher than their averaged around 10 mm in six months during the midyear. Then, the PWV gradually decreased until the end of the year. In addition, the strongly relationship between the rainy day and the PWV was found. 95.76 % of total rainy days (165 days) confirmed that the PWV were higher than their averaged. On the other hand, 69.00 % of total non – rainy days (200 days) showed that the PWV were lower than their averaged. Therefore, the PWV can be used as the key indicator of rain prediction.

Trend of leptospirosis and its association with meteorological factors in Thrissur district, Kerala

Background: Leptospirosis is a common zoonosis caused by bacteria, Leptospira. The core determinants of the disease are the presence of carrier animals, environmental factors and the interaction between man, carrier and the environment. Understanding the type of relation between these factors and leptospirosis will help in controlling the disease. The current study intends to find the trend of leptospirosis cases, to forecast the disease and to correlate number of cases of leptospirosis with meteorological factors.Methods: The data of leptospirosis cases and the meteorological factors in Thrissur district were collected and entered in MS- Excel and statistical analysis was done using SPSS-16.0. For analysing the trend and to forecast the same, time series analysis method was used. The correctness of the model was tested using Ljung-Box statistics.Results: Time series chart, autocorrelation and partial autocorrelation show leptospirosis follows a seasonal trend. Forecasting of leptospirosis cases from July 2018 to May 2019 made by the model matched with original number reported in Thrissur district. Cross correlation of total rainfall and total rainy days showed that leptospirosis peak approximately 1 month after the onset or together with the rain (lag-1 and 0, r0.471 and 0.380 for total rainfall, lag-1 and 0, r0.501 and 0.469 for total rainy days). Humidity positively affects number of leptospirosis cases (lag-1 and 0, r0.464 and 0.435). June to October, seasonally adjusted factor (SAF) was &gt;100% with highest SAF in August (202.2%).Conclusions: Leptospirosis shows a seasonal trend with more cases in June to October and correlates with change in meteorological factors of the region.

Trends in temperature and rainfall extremes during recent years at different stations of Himachal Pradesh

Daily maximum and minimum temperatures of 4 stations and rainfall of 22 stations of Himachal Pradesh for the period of 1970 to 2014 have been used to work out extreme climate indices and trends. The temperature and rainfall indices for different stations studied showed no uniform trend. The results indicated the increasing trend in minimum of maximum and minimum of minimum temperature. The increased frequency of warm nights and warm spell but decrease in the number of hot days and hot nights were observed at Bajaura and Shimla. The maximum one day rainfall amount, maximum 5-day rainfall during the month and very wet days were found to decrease at most of the stations in the state. Consecutive wet days (CWD) and annual total rainy days (PRCPTOT) showed statistically mixed trends at various stations in the state.

Analysis to Xuzhou aerosol optical characteristics with ground-based measurements by sun photometer

Atmospheric aerosols are fine particulate matters suspended in atmosphere, and vary in size distribution, geometrical shape, total column content, and chemical composition. The Aerosol Robotic Network (AERONET) comprised of hundreds of ground-based monitoring stations all over the world aims to measure regularly and continuously the aerosol optical properties, such as aerosol optical depth (AOD) and Angstrom exponent. AERONET has supported the international researches on global, regional and local atmospheric environment issues including aerosol pollution and haze episodes. However, the past researches on China aerosol issues were mainly related with Beijing-Tianjin-Hebei region, Yangtze River delta, and Cheng-Yu plain. It had been much ignored in the Huaihai economic zone, which is also densely populated and economically developed, locates in the north-to-south geographical transition zone of China. An AERONET station was established in 2013 in the Nahu campus of China University of Mining and Technology (CUMT), supported by the China MAESTRO (Mining Area Environment Synergic Observation Proving Ground) program, and a CE318 sun photometer was installed in this station to monitor continuously the characteristics of atmospheric aerosol variations in Xuzhou. The CE318 provides ground measurements on aerosol optical depth (AOD), Angstrom exponent, complex refractive index, single scatter albedo, and some other important aerosol parameters. In this paper, the AERONET CE318 measurements from July 2013 to April 2015 were systematically analyzed to reveal the daily, monthly, and yearly variations of atmospheric aerosols in Xuzhou. Referring to meteorological data including wind speed, relative humidity and total rainy days, the aerosol properties were analyzed with mathematical statistics and K -means cluster methods.

Long‐term change in precipitation structure over the karst area of Southwest China

ABSTRACTThis research analyses the long‐term changes in the precipitation structure over the karst area of southwest China, as recorded by 153 national meteorological stations from 1959 to 2009. Study results are as follows: (1) The karst area of southwest China is categorized into six similar precipitation clusters, including two low‐rainfall clusters located in the western and northern areas and four high‐rainfall clusters distributed in the eastern and southern areas. (2) Although the decreasing trend of annual total precipitation is weak, autumn precipitation decreases significantly over the whole study area. The autumn total precipitation decreases significantly at 51% of the stations because the autumn wind and water vapor flux of the study area gradually decreased, and the autumn low‐latitude and mid‐latitude sea surface temperature (SST) of East Asia continues to rise and gradually leads to positive sea anomalies. (3) The number of rainy days decreases at 85.6% of the stations, especially in the central and southeastern regions of the area. Consequently, almost 53% of the total stations are characterized by an increasing precipitation intensity. (4) The occurrence time of the accumulated percentage precipitation in the western mountain areas is usually later than that in the eastern coastal areas, and the occurrence date of accumulated percentage precipitation (DAP) seems to occur increasingly earlier over the whole study area. (5) Light rain occurs more frequently (76% of annual total rainy days) and contributes 25% to annual total precipitation, whereas although heavy rains such as storms occur less frequently at 3% of annual total rainy days, it contributes almost 19% to annual total precipitation. (6) The occurrence and contribution of wet periods (WPs) decrease with an increase in their duration. WPs with short durations (e.g. 1–4 days) tend to be the predominant precipitation events.

Analysis of the simulated different-class Meiyu precipitation and associated circulation by the BCC_AGCM2.0.1

Based on the output data of Beijing Climate Center Atmospheric General Circulation Model version 2.0.1 (BCC_AGCM2.0.1), this study evaluates the simulated precipitation and associated circulation during the Meiyu period over the Yangtze-Huaihe River Basin (YHRB). The results show that BCC_AGCM2.0.1 can reasonably reproduce the spatial pattern of Meiyu over the YHRB. However, compared to the observation, the model underestimated (overestimated) the torrential and heavy (moderate and light) rainy days, indicating that the more (less) simulated light (torrential) rainy days result in more (less) modeled total rainy days (Meiyu precipitation amount). The simulated Meiyu onset begins in early June, earlier about 20 days than the climatological observation. For duration, Meiyu persists for 15 days, about 5 days shorter than the observation, which may be due to the simulated land-sea thermal contrast is earlier in early June. During the Meiyu period, the distribution patterns of the upper troposphere atmospheric circulation can be well simulated by BCC_AGCM2.0.1, but the obvious deficiency lies in the lower-troposphere air temperature and wind field, especially over Tibetan Plateau area.

Spatial–temporal changes of precipitation structure across the Pearl River basin, China

Using daily precipitation data covering 1960–2005 from 42 stations across the Pearl River basin, precipitation indices, defined by annual total precipitation amount, annual total rainy days, annual precipitation intensity and annual mean rainy days, are analyzed using the modified Mann–Kendall trend test method. Results indicate that: (1) decreasing precipitation is found mainly in the middle and upper Pearl River basin. However, a decreasing number of rainy days is detected almost over the entire basin. Thus, the Pearl River basin is characterized by increasing precipitation intensity, particularly in the middle and the eastern parts of the basin; (2) the occurrence and fractional contribution of wet periods (WPs) with longer durations are decreasing in recent decades and WPs with shorter durations, e.g., 2–5 days are tending to be predominant in recent decades with increasing total precipitation amount. Frequencies of shorter WPs with increased total precipitation amount can be expected, which can easily trigger occurrence of floods and droughts; (3) heavy precipitation is easy to occur in WPs with shorter durations which may further corroborate the intensified precipitation process in the Pearl River basin, particularly in the lower part. Reduction of water supply from the upper Pearl River basin due to decreased precipitation and higher risk of floods and droughts in the lower basin will increase uncertainty of water supply in the lower basin and hence pose new challenges for water supply and water resources management under the influence of climate change and human activities, such as increasing water demand as a result of booming socio-economy and fast population growth.

Influence of some factors on the epidemiology of leaf rust (Cerotelium fici) disease in mulberry (Morus alba L.)

Foliar diseases cause substantial loss in the production and quality of mulberry foliage. Among the various foliar diseases, leaf rust caused by Cerotelium fici constitutes the greatest epidemiological constraint affecting almost all the popular mulberry cultivars cultivated in India. The present study was undertaken to understand the influence of various epidemiological factors on disease development in seven promising mulberry cultivars namely, Local, K2, S13, S34, S36, S54 and MR2 during summer, rainy and winter seasons for three consecutive years. Disease development and its progress were greatly influenced by crop age and weather factors such as maximum and minimum temperature, percentage of relative humidity, cumulative rainfall and total rainy days. Correlation and regression studies indicate that all the variables related to weather factors and crop age were significantly and positively correlated with disease initiation and its development. With increasing crop age, a significant increase in disease severity was recorded in all the mulberry cultivars. The relationship between the crop age and its influence on disease development was better explained by non-linear quadratic function i.e., Y = 0.003x2 + 0.004x − 1.60 and Y = 0.005x2 − 0.170x − 2.09 in rainy and winter seasons, respectively by showing coefficient determination (R2) more than 90% in each case.