scholarly journals Assessment of spatio-temporal variability of rainfall and mean air temperature over Ardabil province, Iran

2021 ◽  
Vol 3 (8) ◽  
Author(s):  
Mohammad Ali Ghorbani ◽  
Saba Mahmoud Alilou ◽  
Sahar Javidan ◽  
Sujay Raghavendra Naganna
Keyword(s):  
Air Temperature ◽  
Coefficient Of Variation ◽  
Temporal Stability ◽  
Rain Gauge ◽  
Temperature Data ◽  
Significance Level ◽  
Linear Correlation Analysis ◽  
Spatio Temporal ◽  
Scale Data ◽  
Precipitation And Temperature

AbstractPrecipitation and temperature are the most important climate parameters, which vary both spatially and temporally. In the present study, rainfall data of 11 synoptic stations and 40 rain gauge stations and mean air temperature data of 11 synoptic stations of Ardabil province for the period 2009–2019 collected from the Meteorological Organization of Ardabil province, were considered for investigation. The descriptive statistics of rainfall and temperature such as mean, median, coefficient of variation, skewness and kurtosis were analyzed for monthly scale data. A higher coefficient of variation signified a greater degree of variation in precipitation and temperature data across different months. To evaluate the temporal stability over several months, Pearson linear correlation analysis at a significance level of 5% was performed for each variable. Kriging geostatistical estimator and GIS interface (ArcMap 10.4.1) were used for spatial interpolation with the aid of root mean square and SRMS standards. The results revealed that the spatial variation of temperature was greater than that of precipitation.

scholarly journals Ondas de calor nas capitais do Sul do Brasil e Montevidéu - Uruguai (Heat waves in the capitals of southern Brazil and Montevideo - Uruguay)

2019 ◽  
Vol 12 (4) ◽  
pp. 1259
Author(s):  
Rafael Brito Silveira ◽  
Maikon Passos Amilton Alves ◽  
Marcelo Barreiro ◽  
Daniel Pires Bitencourt
Keyword(s):  
Heat Wave ◽  
Air Temperature ◽  
Heat Waves ◽  
Kendall Test ◽  
Temperature Data ◽  
Extreme Weather Events ◽  
Southern Brazil ◽  
Porto Alegre ◽  
Significance Level ◽  
Weather Events

Múltiplas partes do globo, possivelmente, passarão a ter dias e noites mais quentes e, com a elevação das temperaturas globais, há tendências de acréscimo do risco de eventos atmosféricos extremos, tais como as ondas de calor. O objetivo principal desse estudo foi verificar as características gerais das ondas de calor nas três capitais da região Sul do Brasil (Curitiba, Florianópolis e Porto Alegre) e também em Montevidéu, capital do Uruguai. Esta análise baseou-se nos parâmetros: frequência, intensidade, duração e suas respectivas tendências. As ondas de calor foram identificadas em uma série de 30 anos de dados diários de temperatura média do ar. As análises de tendência foram averiguadas por meio do teste de Mann-Kendall a um nível de significância de α = 5%. Os resultados mostraram que todos os parâmetros nas quatro cidades apresentam tendências estatisticamente significativas e, com exceção da duração em Montevidéu, todas as demais são positivas. Para além do âmbito das tendências, analisando os parâmetros, comparativamente, conclui-se que Porto Alegre apresenta maior destaque nas médias. Além disto, afirma-se que o inverno é a estação com maior frequência de ondas de calor para todas as cidades.  A B S T R A C TMultiple parts of the globe are likely to have warmer days and nights, and with rising global temperatures, there is a tendency to increase the risk of extreme weather events, such as heat waves. The main objective of this study was to verify the general characteristics of heat waves in the three capitals of southern Brazil (Curitiba, Florianópolis and Porto Alegre) and also in Montevideo, capital of Uruguay. This analysis was based on the parameters: frequency, intensity, duration and their respective trends. Heat waves were identified in a series of 30 years of daily average air temperature data. Trend analyzes were performed using the Mann-Kendall test at a significance level of α = 5%. The results showed that all the parameters in the four cities present statistically significant trends and, except for the duration in Montevideo, all the others are positive. In addition to the scope of the trends, analyzing the parameters, comparatively, it is concluded that Porto Alegre presents greater prominence in the averages. In addition, it is claimed that winter is the season with the highest frequency of heat waves for all cities.Keywords: heat wave, subtropical, capitals, trends, parameters.

scholarly journals Analysis of the Spatio-Temporal Variability of Air Temperature Near the Ground Surface in the Central Baltic Area from 2005 to 2019

Atmosphere ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 60
Author(s):  
Agu Eensaar
Keyword(s):  
Air Temperature ◽  
Ground Surface ◽  
Surface Air Temperature ◽  
Entire Study ◽  
Significance Level ◽  
Average Surface ◽  
Air Temperatures ◽  
Spatio Temporal ◽  
The Difference ◽  
Baltic Area

In this study, we analyzed the changes in the average daily, monthly, seasonal, and annual surface air temperatures based on the temperature data obtained from seven stations (1 January 2005–31 December 2019; 15 years) belonging to the central Baltic area (Stockholm, Tallinn, Helsinki, Narva, Pärnu, Tartu, and Võru). The statistical analysis revealed that there was a strong correlation between the daily average surface air temperature of the studied cities (range: 0.95–0.99). We analyzed the frequency distribution of the average surface air temperatures in addition to the Kruskal–Wallis and Dunn’s tests (significance level of 0.05) to demonstrate that the difference in air temperatures between Narva, Tallinn, Tartu, and Stockholm are critical. The Welch’s t-test (significance level 0.05), used to study the differences in the average monthly air temperature of the cities in question, showed that the surface air temperatures in Stockholm do not differ from Tallinn air temperatures from May to August. However, the surface air temperatures of Narva were similar to those of Tallinn in September. According to our results, the trends in the changes of monthly average surface air temperatures have a certain course during the year (ranging from 1.8 °C (Stockholm) to 4.5 °C (Võru and Tartu) per decade in February). During the entire study period, in addition to February, the surface air temperature increased in all the studied cities in March, May, June, and December, and the surface air temperature did not increase in January or from July to October. During the study period, the average annual surface air temperature in the cities of the central Baltic area increased by 0.43 °C per decade. The results also confirm that the surface air temperature in the study area is changing differently in different cities. The acceleration of the surface air temperature is very alarming and requires a significant intensification of the measures taken to slow down the temperature rise.

scholarly journals Collective ventilation in honeybee nests

2019 ◽  
Vol 16 (150) ◽  
pp. 20180561 ◽  
Author(s):  
Jacob M. Peters ◽  
Orit Peleg ◽  
L. Mahadevan
Keyword(s):  
Air Temperature ◽  
Honey Bees ◽  
Temporal Stability ◽  
Ventilation Strategy ◽  
Air Velocity ◽  
Mediated Communication ◽  
Fluctuating Environments ◽  
Large Nest ◽  
Single Opening ◽  
Spatio Temporal

European honey bees ( Apis mellifera ) live in large congested nest cavities with a single opening that limits passive ventilation. When the local air temperature exceeds a threshold, the nests are actively ventilated by bees fanning their wings at the nest entrance. Here, we show that colonies with relatively large nest entrances use an emergent ventilation strategy where fanning bees self-organize to form groups, separating regions of continuous inflow and outflow. The observed spatio-temporal patterns correlate the air velocity and air temperature along the entrances to the distribution of fanning bees. A mathematical model that couples these variables to known fanning behaviour of individuals recapitulates their collective dynamics. Additionally, the model makes predictions about the temporal stability of the fanning group as a function of the temperature difference between the environment and the nest. Consistent with these predictions, we observe that the fanning groups drift, cling to the entrance boundaries, break-up and reform as the ambient temperature varies over a period of days. Overall, our study shows how honeybees use flow-mediated communication to self-organize into a steady state in fluctuating environments.

scholarly journals Statistical Comparative Study of the Trend and Variation of Meteorological Parameters in Abeokuta, South-West Nigeria

2019 ◽  
pp. 1-15
Author(s):  
M. A. Sodunke ◽  
M. O. Sulaimon ◽  
R. S. Sunmonu ◽  
A. Mabosanyinje ◽  
Y. B. Lawal ◽  
...  
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Comparative Study ◽  
Air Temperature ◽  
Coefficient Of Variation ◽  
Vapour Pressure ◽  
Meteorological Parameters ◽  
Significance Level ◽  
Significant Difference ◽  
The Mean

This study focuses on the statistical comparative study of the trend and variation of meteorological parameters covering a 10 year period (2001-2010) in the capital and largest city of Ogun State, Abeokuta, southwest region of Nigeria. The analyzed meteorological parameters were: wind speed, vapour pressure, relative humidity, temperature, sunshine and rainfall covering 10 years. The calculated coefficient of variation (CV) for sunshine (22.78%), wind speed (21.55%), and rainfall (99.12%) is a proof of exceedance of variability of threshold of 10% while the CV calculated for  air temperature (5.74%), relative humidity (4.52%) and vapour pressure (5.22%) show no significant variability. Significance test of meteorological parameters’ trend reveals a notable reduction in the values of vapour pressure, air temperature and relative humidity. It is, however, difficult to argue for a well-defined change in most of the meteorological parameters based on the monthly time series analyses performed in this work. Only wind speed shows a statistically significant increasing trend during the period of observation at 1% significance level. The trend revealed by rainfall and sunshine is statistically not significant. ANOVA test of significant difference among meteorological parameters show a p-value (Sig.) of 0.000 is an indication of the significant difference in the analyzed mean monthly coefficient of variation for the meteorological parameters under study. The Tukey’s multiple pair comparisons test, however, show that there is a significant difference between the mean monthly CV of rainfall–sunshine, rainfall-vapour pressure, rainfall-wind speed, rainfall-air temperature and rainfall-relative humidity. At the significance level of 5%, the calculated mean monthly CV of rainfall is significantly different from the mean monthly CV of other climatic parameters.

Spatio-temporal analysis of precipitation-based drought indices in Kucuk Menderes River Basin, Turkey

2021 ◽  
Author(s):  
Yonca Cavus ◽  
Ebru Eris ◽  
Hafzullah Aksoy ◽  
Halil Ibrahim Burgan ◽  
Hakan Aksu ◽  
...  
Keyword(s):  
Time Series ◽  
River Basin ◽  
Meteorological Data ◽  
Temperature Data ◽  
Drought Indices ◽  
Drought Severity ◽  
Drought Risk ◽  
Precipitation Data ◽  
Spatio Temporal ◽  
Precipitation And Temperature

<div><span>Drought is one of the extreme hydrological events which may seriously affect the majority of the population in many ways such as economically, socially and environmentally. Researches on the drought analysis may prevent these adverse consequences to a significant extent. Droughts are characterized by using various meteorological and hydrological indicators (i.e. precipitation, temperature, streamflow etc.). These indicators are used to derive drought indices. Spatio-temporal drought is analysed both in time and space by using drought indices based on site-specific precipitation and temperature data. In this study, Standardized Precipitation Index (SPI) using only precipitation data and Standardized Precipitation Evapotranspiration Index (SPEI) using precipitation and temperature data are considered at various time scales changing from 1 to 24 months for a more detailed drought characterization. On the other hand, so-called Dimensionless Precipitation Anomaly Index (DPAI) is introduced at annual scale in this study. The DPAI is used to determine dry periods from the recorded precipitation data. Cases are studied in Kucuk Menderes River Basin located in the Aegean region of Turkey. Precipitation and temperature data obtained from five meteorological stations over the river basin are used to determine drought index time series. Drought risk graphs and drought severity maps are obtained from time series of the drought indices. Drought risk is the likelihood of the drought occurrence that is quantified with the frequency calculated from the SPI and SPEI time series. As for the drought severity maps, they are created to understand its basin-scale variation by using the severities calculated from the dry periods of SPI and SPEI time series. Results show that the prolonged severe historical dry periods of the river basin are correctly identified by the drought indices. These indices used in this study based on easily available meteorological data are simple tools to explain temporal variability at a site or spatial variability over the basin. Also, the spatial distribution of drought severity over the river basin does not show a significant variability though more severe droughts are observed in the inner part of the river basin. Mild drought dominates at each time scale, this stems from the tendency of precipitation fluctuating around the average. Results in the study have considerable importance both in science and practice of drought. Although the methodology established from basic tools using meteorological data, the outcomes of the study are expected to become beneficial for drought management plans.</span></div>

scholarly journals Flow-mediated self-organization of ventilation in honeybee nests

2017 ◽  
Author(s):  
Jacob M. Peters ◽  
Orit Peleg ◽  
L. Mahadevan
Keyword(s):  
Air Temperature ◽  
Honey Bees ◽  
Temporal Stability ◽  
Self Organization ◽  
Air Velocity ◽  
Mediated Communication ◽  
Fluctuating Environments ◽  
Large Nest ◽  
Single Opening ◽  
Spatio Temporal

European honey bees (Apis mellifera) live in large congested nest cavities with a single opening that limits passive ventilation. These nests are actively ventilated by individual bees which fan their wings at the nest entrance when the local air temperature exceeds a threshold. Here we show that colonies with relatively large nest entrances use an emergent ventilation strategy where fanning bees self-organize to form fanning groups, separating regions of continuous inflow and outflow. The observed spatio-temporal patterns correlate the air velocity and air temperature along the entrances to the distribution of fanning bees. A mathematical model that couples these variables to known fanning behavior of individuals recapitulates their collective dynamics. Additionally, the model makes predictions about the temporal stability of the fanning group as a function of the temperature difference between the environment and the nest. Consistent with these predictions, we observe that the fanning groups drift, cling to the entrance boundaries, break-up and reform as the ambient temperature varies over a period of days. Overall, our study shows how honeybees use flow-mediated communication to self-organize into a steady-state in fluctuating environments.

scholarly journals On the Spatial Patterns of Urban Thermal Conditions Using Indoor and Outdoor Temperatures

2021 ◽  
Vol 13 (4) ◽  
pp. 640
Author(s):  
Sadroddin Alavipanah ◽  
Dagmar Haase ◽  
Mohsen Makki ◽  
Mir Muhammad Nizamani ◽  
Salman Qureshi
Keyword(s):  
Heat Stress ◽  
Air Temperature ◽  
Temperature Data ◽  
Cold Spot ◽  
Temperature Pattern ◽  
Outdoor Temperature ◽  
Residential Units ◽  
Urban Settlements ◽  
The Impact ◽  
Indoor And Outdoor

The changing climate has introduced new and unique challenges and threats to humans and their environment. Urban dwellers in particular have suffered from increased levels of heat stress, and the situation is predicted to continue to worsen in the future. Attention toward urban climate change adaptation has increased more than ever before, but previous studies have focused on indoor and outdoor temperature patterns separately. The objective of this research is to assess the indoor and outdoor temperature patterns of different urban settlements. Remote sensing data, together with air temperature data collected with temperature data loggers, were used to analyze land surface temperature (outdoor temperature) and air temperature (indoor temperature). A hot and cold spot analysis was performed to identify the statistically significant clusters of high and low temperature data. The results showed a distinct temperature pattern across different residential units. Districts with dense urban settlements show a warmer outdoor temperature than do more sparsely developed districts. Dense urban settlements show cooler indoor temperatures during the day and night, while newly built districts show cooler outdoor temperatures during the warm season. Understanding indoor and outdoor temperature patterns simultaneously could help to better identify districts that are vulnerable to heat stress in each city. Recognizing vulnerable districts could minimize the impact of heat stress on inhabitants.

scholarly journals Kecenderungan dan Perubahan Hujan Ekstrem Harian di Pulau Madura

2020 ◽  
Vol 18 (1) ◽  
pp. 89-96
Author(s):  
Ahmad Nur Akma Juangga Fura ◽  
Retno Utami Agung Wiyono ◽  
Indarto Indarto
Keyword(s):  
Flood Hazard ◽  
Parametric Method ◽  
Extreme Rainfall ◽  
Kendall Test ◽  
Random Processes ◽  
Rain Gauge ◽  
Rainfall Trend ◽  
Significance Level ◽  
High Level ◽  
Crossing Test

Madura subject to a high level of flood hazard. One of the main causes of flood is extreme rainfall. Global warming generates changes in the amount of extreme rainfall. This research is conducted to identify and to analyze the trends, changes, and randomness of 24-hour extreme rainfall data on Madura Island. The method used is a non-parametric method which includes the Median Crossing test, the Mann-Kendall test, and the Rank-Sum test at the significance level of α =0.05. The analysis was carried out on 31 rain gauge stations. The recording period observed is between 1991-2015. The results of the analysis show that based on the Median Crossing test, most rainfall stations have data originating from random processes. The result shows also that the maximum 24-hour extreme rainfall trend is significantly decreased in a few locations, while for the majority of other stations have no experience a significant trend.

scholarly journals Evaluation of IMERG Level-3 Products in Depicting the July to October Rainfall over Taiwan: Typhoon Versus Non-Typhoon

2021 ◽  
Vol 13 (4) ◽  
pp. 622
Author(s):  
Wan-Ru Huang ◽  
Pin-Yi Liu ◽  
Ya-Hui Chang ◽  
Cheng-An Lee
Keyword(s):  
Real Time ◽  
Tropical Rainfall Measuring Mission ◽  
Temporal Variations ◽  
Rain Gauge ◽  
Advantages And Disadvantages ◽  
Level 3 ◽  
Spatio Temporal ◽  
Typhoon Season ◽  
Early Late ◽  
Better Than

This study assesses the performance of satellite precipitation products (SPPs) from the latest version, V06B, Integrated Multi-satellitE Retrievals for Global Precipitation Mission (IMERG) Level-3 (including early, late, and final runs), in depicting the characteristics of typhoon season (July to October) rainfall over Taiwan within the period of 2000–2018. The early and late runs are near-real-time SPPs, while final run is post-real-time SPP adjusted by monthly rain gauge data. The latency of early, late, and final runs is approximately 4 h, 14 h, and 3.5 months, respectively, after the observation. Analyses focus on the seasonal mean, daily variation, and interannual variation of typhoon-related (TC) and non-typhoon-related (non-TC) rainfall. Using local rain-gauge observations as a reference for evaluation, our results show that all IMERG products capture the spatio-temporal variations of TC rainfall better than those of non-TC rainfall. Among SPPs, the final run performs better than the late run, which is slightly better than the early run for most of the features assessed for both TC and non-TC rainfall. Despite these differences, all IMERG products outperform the frequently used Tropical Rainfall Measuring Mission 3B42 v7 (TRMM7) for the illustration of the spatio-temporal characteristics of TC rainfall in Taiwan. In contrast, for the non-TC rainfall, the final run performs notably better relative to TRMM7, while the early and late runs showed only slight improvement. These findings highlight the advantages and disadvantages of using IMERG products for studying or monitoring typhoon season rainfall in Taiwan.

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