Fire weather indices are one of the basic components of any fire danger early warning system. The Canadian Fire Weather Index (FWI) was developed to indicate the danger due to wildfires in boreal and temperate forests in Canada in the second half of the 20th century. Over time, the FWI has been adapted all over the world and is considered the most widely used fire weather index. This study provides a comprehensive review and meta-analysis of 750 research papers, generalizing the adoption of the FWI across 18 global environmental zones. The objective was to determine FWI values for various fire danger classes worldwide, from very low to extreme. The values of FWI and hydrometeorological variables were compared with wildfire occurrence. Key findings indicate that in drier and warmer climates, higher FWI values (around 50) correspond to high fire danger, whereas in cooler and moister climates, lower FWI values (around 25) signify extreme danger. The analysis of hydrometeorological variables reveals that relative humidity, aridity index, and vapor pressure deficit are significant factors influencing extreme minimum FWI, while average solar radiation has minimal impact. These insights have critical implications for developing effective wildfire prevention and management strategies tailored to specific environmental conditions. By establishing new fire danger classes reflective of regional meteorological and hydroclimatic characteristics, this study enhances the global applicability of the FWI. The ability to quickly adapt the FWI for fire danger forecasting in new areas is particularly beneficial for regions with previously low study coverage. The results underscore the importance of integrating regional climate variables into fire danger assessment frameworks to improve early warning systems and mitigate wildfire risks. The conclusions highlights the effectiveness of the FWI in diverse geographic contexts and its potential to enhance fire danger forecasting globally, thereby aiding in the prevention and management of wildfires.
The phenological phases of field crops have shifted to earlier times in the Czech Republic in recent decades; additionally, they have shown correlations with temperatures from previous spring months. Using a thermal time model called PhenoClim, the correlations between temperatures and phenophases allow us to evaluate the strongest predictors (i.e., maximum temperature) and indicators of base temperatures and growing degree days for the selected phenophases of winter wheat (Triticum aestivum L.). With the help of this model, it is possible to explain 0.6–0.82% of the phase variability and to estimate the onset of phenophases for the selected time period and stations (with the RMSE values of 9.4 days for jointing, 4.3 days for heading, and 5.3 days for full ripeness). To further refine the modeled onsets of phenophases, we used satellite data, specifically the normalized difference vegetation index and the enhanced vegetation index 2 from MODIS; based on these vegetation indices, the start of the growing season (SOS) was determined. After including SOS to model PhenoClim, we modeled the onsets of phenophases, with average accuracies ranging from 6.2 to 15.2. By combining the thermal time model and remote sensing data, specifically the data concerning the determination of SOS, we can refine the modeling of the onset of full ripeness in some locations.
Winter oilseed rape (Brassica napus) is one of the most cultivated oilseeds in the Czech Republic and belongs among major pollen allergens. Pollen allergies have an extensive clinical impact worldwide, and as well as in the Czech Republic. In this paper, meteorological variables such as mean air temperature, maximum and minimum air temperature, precipitation total and number of rainy days in the period 1991–2012 were studied using the PhenoClim phenological model to find the best predictor of the beginning of flowering of the Brassica napus in the Czech Republic. In addition, temporal and spatial evaluations of the beginning of flowering of the Brassica napus were examined at individual stations in different climatic zones within the same period. In total, three phenological stations at altitudes from 270 m asl to 533 m asl located in warm (W2), medium warm (MW7) or cold (C7) climatic zones were used for detailed evaluation. Based on the observation results at selected stations, the beginning of flowering of the Brassica napus advanced progressively in timing (nearly −15 days) in the 1991–2012 period. The base temperature and temperature sums were calculated for the beginning of flowering of the winter oilseed rape using the PhenoClim computer tool. As the most accurate predictor for the beginning of flowering of the Brassica napus, the mean air temperature was determined. The optimal start day for calculation was 30th January, the threshold (base temperature) was 6.0 °C and the temperature sum was 157.0 °C. The RMSE value was 4.77 and the MBE value was −3.00. The simulated data had a good correlation with the real observed data (the correlation coefficients were within the range from 0.56 to 0.76), and the PhenoClim model results indicate using them in the forecast modeling of the beginning of flowering of the Brassica napus in the Czech Republic.
19 March 2012 in Clinical and Applied Thrombosis/Hemostasis
Introduction: Sticky platelet syndrome (SPS) is most likely a hereditary thrombophilia characterized by platelet hyperaggregation after low concentrations of platelet inducers—adenosine diphosphate and/or epinephrine. We present 9 kindreds with SPS familial occurrence. Material and Methods: Familial trait of SPS was looked up in the database of the National Center of Hemostasis and Thrombosis. Families with at least 3 SPS-positive members were studied, described, and presented. Results: In the group of 1093 symptomatic patients, SPS was confirmed in 240 cases. Familial occurrence with at least 3 SPS-positive relatives was found in 9 cases. Conclusion: The exact pathogenesis of SPS is not sufficiently explained. Our findings seem to support the idea that SPS might have an autosomal dominant hereditary fashion.
7 January 2025 in International Journal of Biometeorology
Phenological shifts in wild-growing plants and wild animal phenophases are well documented at many European sites. Less is known about phenological shifts in agricultural plants and how wild ecosystem phenology interacts with crop phenology. Here, we present long-term phenological observations (1961–2021) from the Czech Republic for wild plants and agricultural crops and how the timing of phenophases differs from each other. The phenology of wild-growing plants was observed at various experimental sites with no agriculture or forestry management within the Czech Hydrometeorological Institute observations. The phenological data of the crops were collected from small experimental plots at the Central Institute for Supervising and Testing in Agriculture. The data clearly show a tendency to shift to earlier times during the observation period. The data also show some asynchrony in phenological shifts. Compared with wild plants, agricultural crops showed more expressive shifts to the start of the season. Phenological trends for crop plants (Triticum aestivum) showed accelerated shifts of 4.1 and 5.1 days per decade at low and middle altitudes, respectively; on the other hand, the average phenological shift for wild plants showed smaller shifts of 2.7 and 2.9 days per decade at low and middle altitudes, respectively. The phenophase ´heading´ of T. aestivum showed the highest correlation with maximum temperatures (r = 0.9), followed by wild species (with r = 0.7–0.8) and two remaining phenophases of T. aestivum jointing and ripening (with r = 0.7 and 0.6). To better understand the impacts of climate on phenological changes, it is optimal to evaluate natural and unaffected plant responses in wild species since the phenology of field crops is most probably influenced not only by climate but also by agricultural management.
Climate change affects the agroecological conditions and persistence of cherry tree flowering. Detailed evaluation of minimum air temperature and occurrence of synoptic events occurrence during spring frosts within the cherry tree flowering in the Czech Republic (Central Europe) is missing. The main objective of this study was to evaluate the above-mentioned variables during the cherry tree flowering in different parts of the country from 1924 to 2012. Our question was how the frequency of frost days occurrence changed during the cherry tree flowering. A trend analysis was conducted with the Mann-Kendall test. The onset of the beginning of flowering and end of flowering shifted to an earlier date per the whole examined period (up to −13.9 and −8.1 days) and the period of flowering extended (up to 4.1 days). The shifts were more pronounced at higher elevations. During the period of the cherry tree flowering, the trend in change of the number of frost days was negative at the lowland station (−0.3 day) and positive at the highland station (+1.2 day). At all stations, “Ap3” synoptic event (anticyclone) occurrence during cherry tree flowering on days with the highest spring frost risk (Tmin at 2 m < −1.1 °C) prevailed. The positive trend of frost-day occurrence and the negative trend of minimum air temperature in cherry tree flowering indicate that blossoms are more endangered at higher elevations.