Number Of Tropical Days Research Articles

Considerations regarding the evolution of extreme temperatures in the Banat Plain in the last six decades

During cold winter nights we often hear the question "where is the global warming, should it not be warmer?". Low temperatures that can still be recorded in the Banat Plain during winter or media reports of cold waves affecting various regions worldwide seem to the common man to be in total contradiction with the concerns of the scientific community about global warming. With this article we are trying to follow the evolution of some meteorological parameters that can affect the population in one way or another, namely number of tropical days, number of winter days, number of tropical nights, number of frosty nights, absolute maximum and minimum temperatures. Thus, the data obtained from the three national meteorological services (Romanian, Hungarian, and Serbian) operating on the territory of the Banat Plain were grouped in a common database and analyzed both in Excel and with the help of the non-parametric Mann-Kendall test, obtaining a series of conclusions on the evolution of the abovementioned parameters, as well as on the way how the increase in the risk of high temperatures is compensated (or not) by the decrease in the risk of low temperatures.

Trends in Air Temperature and Precipitation in Southeastern Czech Republic, 1961-2020

This study presents a summary of sixty years of air temperature and precipitation measurements at the Žabčice weather station, located in the southeastern Czech Republic and operated by Mendel University in Brno. An instrumental dataset spanning two climatological normal periods (1961- 1990 and newly established 1991-2020) is analyzed for long term linear trends with monthly data presented in full span in Appendices. In the new climate normal period, the mean annual temperature increased from 9.3 °C to 10.3 °C with growing trend of 0.34 °C/10 years (p < 0.001). Every calendar month of year is warmer, with the highest and fastest increase in August (+2.0 °C, 0.64 °C/10 years, p < 0.001) and the lowest in October (+0.2 °C). Annual precipitation sum increased negligibly (+11.1 mm), however, the quarterly distribution significantly changes towards drier second quarter (-22.9 mm, p < 0.05) and wetter third quarter (+37.1 mm, p < 0.05). Number of tropical days (maximum daily air temperature > 30 °C) significantly increased (+4.44/10 years, p < 0.001), whereas number of frost days is negligibly decreasing (-0.88/10 years). Temperature derived Huglin index for vineyards increased by 369 °C to a seasonal sum 2062 °C (+84 °C/10 years, p < 0.001). This study provides evidence of the rate of changing climate at this southern Moravia lowland site. This study provided a summary and trend analysis of instrumental air temperature and precipitation dataset measured at Žabčice locality during the period 1961-2020, supplemented with selected agroclimatic indices. The dataset was utilized to establish a new climatological normal for the period 1991-2020 and both normal periods 1961-1990 and 1991-2020 were compared. We can conclude, that the mean air temperature is increasing on monthly, quarterly and yearly timescales. The fastest warming trend was observed during the growing season, peaking in June-August. There is an evident increase in extreme heat waves and other temperature-related indices, such as the Huglin index, suggesting a further rise in air temperature in the near future. Annual precipitation sums increased negligible, however, we can confirm a change in temporal distribution on an annual scale, in terms of decrease in the second quarter and increase in the third quarter. Supported by the Ministry of Education, Youth and Sports of the Czech Republic for the project SustES - Adaptation Strategies for the Sustainability of Ecosystem Services and Food Security in Adverse Natural Conditions, Project No. CZ.02.1.01/0.0/0.0/16_019/0000797, and by the National Agency for Agricultural Research, Ministry of Agriculture of the Czech Republic, Project No. QK1910338 "Early warning agrometeorological system for biotic and abiotic risks".

Reassessment of the homogenization of daily maximum temperatures in the Netherlands since 1901

In 2016, the Royal Dutch Meteorological Office (KNMI) homogenized the daily temperature records for the Netherlands from 1901 to 1950 to allow a realistic comparison of the temperatures from 1901 to the present. The homogenizations for the main station De Bilt were carried out using a Percentile Matching Method (PMM) with one reference station and a 56-month reference period. In this study, it is shown that the corrections in the number of tropical days (maximum temperature ≥ 30 °C) depend strongly on the choice of the reference station and the length of the reference period. A total of 116 different variants of the homogenization of De Bilt were carried out, using all combinations of five reference stations, five reference periods, two ways to calculate percentiles, and two ways to smooth the data. The parameters used for the KNMI’s current homogenization of De Bilt result in a very sharp decrease of tropical days, which is not replicated by the majority of the 116 variants. Moreover, after homogenization, De Bilt appears to be an outlier compared to the other meteorological stations. Therefore, the current homogenized estimates of tropical days for De Bilt should be treated with considerable caution.

Changes in the extreme air temperature in Czech Republic

This study is focused on air temperature in Czech Republic in relation to selected climatological indices for extreme hot and extreme cold days for the period 1961- 2017. The number of summer days (SU) and number of tropical days (SU30) have been chosen as the indicators of extreme hot days. For the indicators of extreme cold days, the number of frost days (FD) and number of icing days (ID) have been analyzed. The analyses are based on the daily data for air temperature measured at eight meteorological stations situated at the regions with different geographical and climate conditions. The data are freely available from the website of the Czech Hydrometeorological Institute. The results of the study show negative trend of extreme cold events and positive trend of extreme hot temperatures. With a few exceptions, the trend is statistically significant at p=0.05. The trend values for the indicators of cold days are higher than those for the indicators of warm days. The results show a faster change in air temperature for the cold part of the year

Nutrients, bioactive compounds, and minerals in the juices of 16 varieties of apple (Malus domestica) harvested in Austria: A four-year study investigating putative correlations with weather conditions during ripening

This study was conducted to examine putative correlations between weather parameters during April-September and the amounts of nutrients, minerals and bioactive compounds in the juices of 16 apple varieties from four harvest years in Lower Austria. For most sugar-parameters, negative correlations were found with the total precipitation (r between −0.42 and −0.64). Conversely, positive correlations were observed with the mean air temperature (r between 0.32 and 0.66), the global radiation (r between 0.32 and 0.61) and the number of tropical days (r between 0.39 and 0.51). The sum of 14 polyphenols (HPLC quantitation) was positively correlated with the mean air temperature and global radiation (rs 0.44 and 0.42). Negative correlations were observed between the global radiation and potassium, magnesium and calcium contents (correlation coefficients −0.49, −0.68 and −0.69). We conclude that increased temperatures and global radiation can be correlated with enhanced sugar synthesis and polyphenol formation.

CHANGES IN SUMMER AND TROPICAL DAYS AT THE LAKES DISTRICT OF THE MEDITERRANEAN REGION OF TURKEY BETWEEN THE PERIOD OF 1969-2014

Summer and tropical days are determined about the daily maximum air temperature values. Examining the annual numbers of summer and tropical days is one of the methods to reveal changes and trends in air temperatures and therefore in climate on a global, regional and local scale. This study aims to examine the long-term changes and trends of the annual numbers of summer and tropical days of the Lakes District of Turkey, which is located in the transition zone between Mediterranean climate and Central Anatolia continental climate between the period of 1969–2014 at 11 meteorological stations. Singular scanning method was used in the study. The results suggest that the numbers of summer and tropical days changed within the years of the period examined. In the analyzed period, it has been determined that the annual numbers of summer and tropical days and the annual numbers of tropical days change within years and periods, and show an increase, and trend lines also indicate an increase. It was determined that the number of tropical days showed a significant increase trend in all stations and in the average of the study area. Also, it has been determined that the annual numbers of summer days generally decrease over the years and periods and the trend lines also indicate a decrease. The number of summer days shows a decreasing trend that is not significant in Beyşehir, Eğirdir and Uluborlu stations, but significant in other stations and in the average of the study area. The increasing trend in tropical days can be considered as a potential risk for human health and activities and natural environment.

Long-term development and prediction of climate extremity and heat waves occurrence: Case study for agricultural land

AbstractAccording to the IPCC it is possible to predict larger weather extremity associated with more frequent occurrence of heat waves. These waves have an impact not only on the health status of the population, on economic, social and environmental spheres, but also on agricultural landscape and production. The paper deals with the issue of climate extremity and addresses mainly the occurrence of characteristic days (tropical, summer, freezing, ice and arctic) and heat waves. The south-eastern Moravia belongs to the warmest regions of the Czech Republic. Since the area is not urban, it is not affected by urban heat islands. Thus, it can be used as a representative area of climate change in terms of weather extremes. Heat wave occurrence and length analysis was performed for the period of 1931–1960 and 1961–2013. In addition, a prospective analysis was carried out for the period of 2021–2100 where the scenario data of the Czech Hydrometeorological Institute were used. Between 1961 and 1990, heat waves appeared from June to September. The prediction for the next two decades shows that heat waves may appear as early as May. Furthermore, the average count of days in heat waves increased from 6.13 days (1961–1990) to 36 days (2071–2100). A statistically significant increase in the annual number of tropical days (from 9 to 20 days) was found in the assessment of characteristic days for the period 1961–2013. A highly conspicuous trend was found in July and a prominent trend was identified in May. A statistically highly significant trend was also observed in the annual number of summer days.

Impact of Temperature and Wetness of Summer Months on Autumn Vegetative Phenological Phases of Selected Species in Fageto-Quercetum in the Years 2011-2015

The work presents the result of the drought impact on the onset and the development of autumn phenological phases of tree species (Quercus robur L., Carpinus betulus L., Prunus avium L.) in the central part of Slovakia. The selected autumn phenological phases of tree species were observed in the years from 2011 to 2015. From meteorological parameters we examined precipitation, number of tropical days, and their periods from June to August. We revealed distinct differences in air temperature and precipitation between the years, which affected the onset of individual phenological phases. Based on the calculations of the Thornthwaite moisture index and climatic water balance, the year 2014 was wet (except for June) with the shortest periods of tropical days. The extreme drought and the longest 13‑day period of tropical days in the year 2015 shifted leaf colouring of hornbeam and cherry tree by 16 and 22 days earlier and the leaf fall by 5 and 16 days earlier than the average of the period from 2011 to 2015. Oak was the least sensitive to the weather extremes, which was documented by a balanced course of the phenological phases with the lowest variation. The 5‑year‑long average onset of the autumn phenophases of oak and hornbeam was shifted by 1 – 4 days later and of cherry tree by 4 days earlier than the 25‑year‑long average.

Projection of drought-inducing climate conditions in the Czech Republic according to Euro-CORDEX models

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 70:179-193 (2016) - DOI: https://doi.org/10.3354/cr01424 Projection of drought-inducing climate conditions in the Czech Republic according to Euro-CORDEX models Petr Štěpánek1,2,*, Pavel Zahradníček1,2, Aleš Farda1, Petr Skalák1,2, Miroslav Trnka1,3, Jan Meitner1, Kamil Rajdl1 1Global Change Research Institute CAS, Belidla 986/4a, Brno 60300, Czech Republic 2Czech Hydrometeorological Institute, Na Šabatce 2050/17, Praha 14306, Czech Republic 3Institute of Agriculture Systems and Bioclimatology, Mendel University in Brno, Zemedelska 1, 613 00 Brno, Czech Republic *Corresponding author: stepanek.p@czechglobe.cz ABSTRACT: The end of the 20th century and the beginning of the 21st century in the Czech Republic were characterized by frequent extreme water cycle fluctuations, i.e. the occurrence of increased incidences of flood and drought events. Drought occurs irregularly in the Czech Republic during periods with low precipitation amounts. The most noteworthy droughts with significant impact, especially to agriculture, occurred in the years 2000, 2003, 2007, 2009, 2012, 2014 and 2015. A significant increase in frequency and length of drought periods was detected in future climate projections based on the latest model outputs, such as from the Euro-CORDEX 0.11° resolutions for the European area. For these model experiments, the following greenhouse gas emissions scenarios were used: Representative Concentration Pathway (RCP) 4.5 (milder scenario) and RCP8.5 (pessimistic scenario). Since the climate models suffer from potentially severe biases, it is necessary to statistically correct their outputs. For this purpose, a suitable reference dataset was prepared, based on quality-controlled, homogenized and gap-filled station time series. The correction method applied was based on variable correction using individual percentiles. From the corrected model outputs, selected extreme indexes with respect to drought analysis were calculated. From the results, it follows that we can expect both an increase in air temperature and in precipitation (with increased amounts per event), as well as an increase in other extremes with the capability of inducing drought (number of tropical days, heat waves, etc.). KEY WORDS: Euro-CORDEX simulations · Model bias correction · Climate change · Drought indices · Czech Republic Full text in pdf format Supplementary material PreviousNextCite this article as: Šteˇpánek P, Zahradníček P, Farda A, Skalák P, Trnka M, Meitner J, Rajdl K (2016) Projection of drought-inducing climate conditions in the Czech Republic according to Euro-CORDEX models. Clim Res 70:179-193. https://doi.org/10.3354/cr01424 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 70, No. 2-3. Online publication date: October 27, 2016 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2016 Inter-Research.

Development and Prediction of Selected Temperature and Precipitation Characteristics in Southern Moravia

In recent years, rising temperatures and changes in precipitation patterns have a significant impact on agriculture. This paper presents analyses of selected climatic characteristics of the South Moravian region. The evaluation was based on the data from the Czech Hydrometeorological Institute. Climatic data for future periods were gained using the A1B emission scenario. With regard to the agricultural activity of this region, climatic characteristics (average air temperature, heat waves, average precipitation and periods without precipitation) were selected and compared in the following three periods 1961–1990, 2021–2050 and 2071–2100. The results showed an increase of the average air temperature, increase in the number of tropical days and days in heat waves. It was also found that as a result of rising air temperatures and different distribution of precipitation, the period of drought will significantly prolong in the future. Very unfavourable climate situation is expected in the particular period of 2071–2100 in this region. Increasing drought, predicted by climate models, presents major problem for the agriculture of South Moravia. It is necessary to adapt to these anticipated changes not only in the agricultural activities but also in the landscape management in general.

Summer hazards in Novi Sad

Review of summer atmospheric condition that may influence on human health and environment in city Novi Sad, Serbia is depicted in this study. Frequency of tropical days, heat wave duration and severity and erithemal ultraviolet (UV) dose during summer months (June-August) are analyzed for the period 1981-2009. The frequency of tropical days and anomalies of maximum temperatures above normal were on the rise 0.63°C and 0.07°C per year, respectively. A very low occurrence of heat waves was typical in the 1980s and early 1990s. The longest heat waves were recorded in 2003 (lasting 12 days) and 2002 (11 days) while the strongest were in 2007 and 2003. An empirical formula for estimating the daily sum of the erithemal UV radiation from global radiation during summer months has been derived and applied for reconstruction. The daily erithemal UV doses were the greatest in 2000 and 2007, 3997.32 J/m2 and 3818.11 J/m2 respectively. Analysis shows an increasing trend of erithemal UV doses (11.52 J m-2 per year). Considering heat waves, number of tropical days, anomalies of maximum temperatures and erithemal UV doses the conclusion is that the most hazardous summer regarding the human health in Novi Sad was in 2000, 2003 and 2007.

Variability of tropical days over Greece within the second half of the twentieth century

Tropical days (TD) are defined as the days with a maximum air temperature greater than 30.0 °C. It is clear that the study of TD includes also the absolute maximum temperatures, which are of great interest for the description of a region’s climate. These days are considered as very hot, and they particularly are of great importance not only for bioclimatology and applied sciences, but also for the individuals who are sensitive in the heat-stress. The regime of the TD in Greece is the focus of this study. The aim is to demonstrate their changes from decade to decade, for the time period 1960–2000. For this study, the Annual Number of Tropical Days (ANTD) recorded by each of the 26 meteorological stations of National Meteorological Service, which are uniformly distributed in the Hellenic peninsula, was calculated and analysed. In terms of quantifying the conditions in a humanbiometeorological manner, the thermal index Physiological Equivalent Temperature (PET) and the consecutive days for Athens have been included in this study. The trends of the TD for each station were analysed through the Mann–Kendall technique, while the spatial distribution per decade reveals the regions with change (increase or decrease) in the ANTD during the examined period. Two characteristic periods of change for the ANTD appear in the majority of the meteorological stations in Greece. The first period (1955–1976) is determined by a negative trend, which is statistically significant (c.l. 95%), for adequate stations. In the period between 1976 and 2000, the increase in the ANTD and the maximum temperature exceed the corresponding maximum that appeared in the beginning of the 1950s for several of the examined meteorological stations. The human-biometeorological analysis shows that the consecutive days of PET > 35 °C have had a positive trend in the last two decades of the last century.

Heat Waves in the South Moravian Region During the Period 1961-1995

Heat waves (periods of extremely hot summer weather) in the region of south Moravia are in the focus of this study. The introduced definition consists of three requirements imposed on the period that is considered a heat wave: at least three days with T MAX ≥30.0°C must be observed; the mean T MAX over the whole period is at least 30.0°C; and T MAX must not drop below 25.0°C. To compare the severity of the individual heat waves, various characteristics (duration, number of tropical days, peak temperature, cumulative temperature excess, precipitation amount) are examined. The heat wave index HWI is defined to express the severity of heat waves in the most comprehensive way.