Forecasting diurnal variations in meteorological parameters for predicting fire behaviour

1989 ◽  
Vol 19 (6) ◽  
pp. 791-797 ◽  
Author(s):  
J. A. Beck ◽  
A. C. F. Trevitt
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Absolute Humidity ◽  
Diurnal Variations ◽  
Day Length ◽  
Maximum Temperature ◽  
Daily Maximum ◽  
Fire Behaviour ◽  
Julian Date ◽  
Time Of Year

Empirical models for predicting diurnal variations in air temperature, wind speed, and relative humidity, given daily maximum and minimum values, latitude, and Julian date, have been developed. Solar heating during the daytime is quantitatively depicted using a truncated sine function, and nighttime cooling is characterized by an exponential decay function. Daily wind-speed trends echo diurnal temperature patterns, and relative humidity is modelled as a function of temperature by assuming that absolute humidity remains constant throughout the day. The time of occurrence of daily maxima and minima in temperature and wind speed varies seasonally according to changes in day length. Maximum temperature and wind speed typically occur later in the day than the maximum solar insolation. The magnitude of this lag depends on both time of year and latitude. The models were parameterized for two locations in Australia and observed, and modelled variations in temperature, relative humidity, and wind speed were used to forecast diurnal trends in fire behaviour. Predicted fire behaviour compared favourably in the two cases considering the very simple modelling approach employed.

scholarly journals Analysis of how dry-hot wind hazard has changed for winter wheat in the Huang-huai-hai plain

2016 ◽  
Author(s):  
Benlin Shi ◽  
Xinyu Zhu ◽  
Hongzhong Li ◽  
Yunchuan Hu ◽  
Yi Zhang
Keyword(s):  
Climate Change ◽  
Wind Speed ◽  
Relative Humidity ◽  
Winter Wheat ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Annual Average ◽  
Wheat Production ◽  
Wind Hazard

Abstract. Climate change is exerting significant impacts on global agricultural production. Climatic variations adversely affect crop production and, thus tend to impose a key constraint of agricultural production, primarily on how to cont inuously enhance the winter wheat yields worldwide. The high uncertainties in predicting the effects of climate change on wheat production are most likely due to rare understanding on the responses of wheat production to extreme climatic factors, e.g. high temperatures, low humidity as well as high wind speed. Dry-hot wind hazard represents one of the main natural disasters for Chinese winter wheat production, especially for the Huang-huai-hai plain. However, high uncertainties of the effects of dry-hot wind hazard on winter wheat production still exist, mainly due to the gaps of long-term observations. Therefore, we selected Shangqiu as the case study area to determine the occurrence regularity of dry-hot wind hazard on winter wheat production in Huang-huai-hai plain. We analyzed regional meteorological data with daily resolution in the later growth stage of winter wheat during the period of 1963 to 2012. In accordance with the meteorological industry standards of “Disaster Grade of Dry-hot Wind for Wheat” by the China Meteorological Administration, we synthesized analyzed the distribution of annual average days of dry-hot wind in winter wheat growing seasons and the associated responses to the climate change. Hence the relationships between dry-hot wind times and winter wheat yields were also discussed. The results showed that the annual average days of light and severe dry-hot wind exhibited tended to decline in the recent 50 years. Great inter-annual variations of light and severe dry-hot wind were observed. The significant inter-annual variations were related with the corresponding meteorological conditions of temperature, moisture and wind speed. The most serious damages of light and severe dry-hot wind both occurred in 1960s while the damages appeared less in the 1980s and the last decade, which could be also explained by the corresponding temperature, moisture and wind speed conditions. From 1963 to 2012, a climatic mutation point of daily maximum temperature was found near 1972, but insignificantly (p>0.05). The wind speed at 2:00 pm and the relative humidity at 2:00 pm were closely related to the hazard conspicuously. A climatic mutation point of the wind speed at 2:00 pm was found near 1984, and climatic mutation of the relative humidity at 2:00 pm was found near 1981 (p<0.05). Daily maximum temperature, wind speed at 2:00 pm and the relative humidity at 2:00 pm played a major role in decreasing trend of dry-hot wind disaster, and the significantly decreased of wind speed at 2:00 pm constituted a main factor in Shangqiu. Dry-hot wind hazard is very sensitive to climate change. Yields of winter wheat were negatively correlated with annual average days of dry-hot wind in Shangqiu (p<0.05). In actual practices, great concerns should be paid on the defense of dry-hot wind for winter wheat production. Thus the most effective practices have to be taken for enhancing the resistance of winter wheat to dry-hot wind hazard through improving filed microclimate condition.

scholarly journals SEASONAL AND INTERANNUAL PATTERN OF METEOROLOGICAL VARIABLES IN CUIABÁ, MATO GROSSO STATE, BRAZIL

2015 ◽  
Vol 33 (3) ◽  
pp. 477 ◽  
Author(s):  
Nadja Gomes Machado ◽  
Marcelo Sacardi Biudes ◽  
Carlos Alexandre Santos Querino ◽  
Victor Hugo De Morais Danelichen ◽  
Maísa Caldas Souza Velasque
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Meteorological Data ◽  
Seasonal Pattern ◽  
Global Radiation ◽  
Meteorological Variables ◽  
Maximum Temperature ◽  
Wet Season ◽  
Agricultural Producers ◽  
Mato Grosso

ABSTRACT. Cuiab´a is located on the border of the Pantanal and Cerrado, in Mato Grosso State, which is recognized as one of the biggest agricultural producers of Brazil. The use of natural resources in a sustainable manner requires knowledge of the regional meteorological variables. Thus, the objective of this study was to characterize the seasonal and interannual pattern of meteorological variables in Cuiab´a. The meteorological data from 1961 to 2011 were provided by the Instituto Nacional de Meteorologia (INMET – National Institute of Meteorology). The results have shown interannual and seasonal variations of precipitation, solar radiation, air temperature and relative humidity, and wind speed and direction, establishing two main distinct seasons (rainy and dry). On average, 89% of the rainfall occurred in the wet season. The annual average values of daily global radiation, mean, minimum and maximum temperature and relative humidity were 15.6 MJ m–2 y–1, 27.9◦C, 23.0◦C, 30.0◦C and 71.6%, respectively. Themaximum temperature and the wind speed had no seasonal pattern. The wind speed average decreased in the NWdirectionand increased in the S direction.Keywords: meteorological variables, climatology, ENSO. RESUMO. Cuiabá está localizado na fronteira do Pantanal com o Cerrado, no Mato Grosso, que é reconhecido como um dos maiores produtores agrícolas do Brasil. A utilização dos recursos naturais de forma sustentável requer o conhecimento das variáveis meteorológicas em escala regional. Assim, o objetivo deste estudo foi caracterizar o padrão sazonal e interanual das variáveis meteorológicas em Cuiabá. Os dados meteorológicos de 1961 a 2011 foram fornecidos pelo Instituto Nacional de Meteorologia (INMET). Os resultados mostraram variações interanuais e sazonais de precipitação, radiação solar, temperatura e umidade relativa do ar e velocidade e direção do vento, estabelecendo duas principais estações distintas (chuvosa e seca). Em média, 89% da precipitação ocorreu na estação chuvosa. Os valores médios anuais de radiação diária global, temperatura do ar média, mínima e máxima e umidade relativa do ar foram 15,6 MJ m–2 y–1, 27,9◦C, 23,0◦C, 30,0◦C e 71,6%, respectivamente. A temperatura máxima e a velocidade do vento não tiveram padrão sazonal. A velocidade média do vento diminuiu na direção NW e aumentou na direção S.Palavras-chave: variáveis meteorológicas, climatologia, ENOS.

Spatiotemporal Variability of Potential Evaporation in Heihe River Basin Influenced by Irrigation

2020 ◽  
Author(s):  
Congying Han
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Spatial Pattern ◽  
River Basin ◽  
Meteorological Factors ◽  
Heihe River Basin ◽  
Spatiotemporal Variability ◽  
Maximum Temperature ◽  
Heihe River ◽  
Potential Evaporation

&lt;p&gt;&lt;strong&gt;Spatiotemporal Variability of Potential Evaporation in Heihe River Basin Influenced by Irrigation &lt;/strong&gt;&lt;/p&gt;&lt;p&gt;Congying Han&lt;sup&gt;1,2&lt;/sup&gt;, Baozhong Zhang&lt;sup&gt;1,2&lt;/sup&gt;, Songjun Han&lt;sup&gt;1,2&lt;/sup&gt;&lt;/p&gt;&lt;p&gt;&lt;sup&gt;1&lt;/sup&gt; State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100038, China.&lt;/p&gt;&lt;p&gt;&lt;sup&gt;2&lt;/sup&gt; National Center of Efficient Irrigation Engineering and Technology Research-Beijing, Beijing 100048, China.&lt;/p&gt;&lt;p&gt;Corresponding author: Baozhong Zhang ([email protected])&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Abstract: &lt;/strong&gt;Potential evaporation is a key factor in crop water requirement estimation and agricultural water resource planning. The spatial pattern and temporal changes of potential evaporation calculated by Penman equation (E&lt;sub&gt;Pen&lt;/sub&gt;) (1970-2017) in Heihe River Basin (HRB), Northwest China were evaluated by using data from 10 meteorological stations, with a serious consideration of the influences of irrigation development. Results indicated that the spatial pattern of annual E&lt;sub&gt;Pen&lt;/sub&gt; in HRB was significantly different, among which the E&lt;sub&gt;Pen&lt;/sub&gt; of agricultural sites (average between 1154 mm and 1333 mm) was significantly higher than that of natural sites (average between 794 mm and 899 mm). Besides, the coefficient of spatial variation of the aerodynamic term (E&lt;sub&gt;aero&lt;/sub&gt;) was 0.4, while that of the radiation term (E&lt;sub&gt;rad&lt;/sub&gt;) was 0.09. The agricultural irrigation water withdrawal increased annually before 2000, but decreased significantly after 2000 which was influenced by the agricultural development and the water policy. Coincidentally, the annual variation of E&lt;sub&gt;pen&lt;/sub&gt; in agricultural sites decreased at -40 mm/decade in 1970-2000 but increased at 60 mm/decade in 2001-2017, while that in natural sites with little influence of irrigation, only decreased at -0.5mm/decade in 1970-2000 but increased at 11 mm/decade in 2001-2017. So it was obvious that irrigation influenced E&lt;sub&gt;pen &lt;/sub&gt;significantly and the change of E&lt;sub&gt;pen&lt;/sub&gt; was mainly caused by the aerodynamic term. The analysis of the main meteorological factors that affect E&lt;sub&gt;pen&lt;/sub&gt; showed that wind speed had the greatest impact on E&lt;sub&gt;pen&lt;/sub&gt; of agricultural sites, followed by relative humidity and average temperature, while the meteorological factors that had the greatest impact on E&lt;sub&gt;pen&lt;/sub&gt; of natural sites were maximum temperature, followed by wind speed and relative humidity.&lt;/p&gt;

Assessment of the future climate potential for tourism over Europe using a combination of downscaling approaches and quantitative impact models

2020 ◽  
Author(s):  
Maria Francisca Cardell ◽  
Arnau Amengual ◽  
Romualdo Romero
Keyword(s):  
Climate Change ◽  
Wind Speed ◽  
Relative Humidity ◽  
Future Climate ◽  
Cumulative Distribution ◽  
Maximum Temperature ◽  
Model Errors ◽  
Present Climate ◽  
Ensemble Strategy ◽  
The Future

&lt;p&gt;Europe and particularly, the Mediterranean countries, are among the most visited tourist destinations worldwide, while it is also recognized as one of the most sensitive regions to climate change. Climate is a key resource and even a limiting factor for many types of tourism. Owing to climate change, modified patterns of atmospheric variables such as temperature, rainfall, relative humidity, hours of sunshine and wind speed will likely affect the suitability of the European destinations for certain outdoor leisure activities.&lt;/p&gt;&lt;p&gt;Perspectives on the future of second-generation climate indices for tourism (CIT) that depend on thermal, aesthetic and physical facets are derived using model projected daily atmospheric data and present climate &amp;#8220;observations&amp;#8221;. Specifically, daily series of 2-m maximum temperature, accumulated precipitation, 2-m relative humidity, mean cloud cover and 10-m wind speed from ERA-5 reanalysis are used to derive the present climate potential. For projections, the same daily variables have been obtained from a set of regional climate models (RCMs) included in the European CORDEX project, considering the rcp8.5 future emissions scenario. The adoption of a multi-model ensemble strategy allows quantifying the uncertainties arising from the model errors and the GCM-derived boundary conditions. To properly derive CITs at local scale, a quantile&amp;#8211;quantile adjustment has been applied to the simulated regional scenarios. The method detects changes in the continuous CIT cumulative distribution functions (CDFs) between the recent past and successive time slices of the simulated climate and applies these changes, once calibrated, to the observed CDFs.&amp;#160;&lt;/p&gt;&lt;p&gt;Assessments on the future climate potential for several types of tourist activities in Europe (i.e., sun, sea and sand (3S) tourism, cycling, cultural, football, golf, nautical and hiking) will be presented by applying suitable quantitative indicators of CIT evolutions adapted to regional contexts. It is expected that such kind of information will ultimately benefit the design of mitigation and adaptation strategies of the tourist sector.&lt;/p&gt;

scholarly journals Does an August Singularity Exist in the Northern Rockies of the United States?

2008 ◽  
Vol 47 (6) ◽  
pp. 1845-1850
Author(s):  
Peter T. Soulé ◽  
Paul A. Knapp
Keyword(s):  
United States ◽  
Late Summer ◽  
The United States ◽  
Maximum Temperature ◽  
Daily Maximum ◽  
Northern Rocky Mountains ◽  
Temperature Anomalies ◽  
Northern Rockies ◽  
Maximum Temperatures ◽  
Time Of Year

Abstract Climatic singularities offer a degree of orderliness to notable meteorological events that are typically characterized by significant temporal variability. Significant deviations from normal daily maximum temperatures that occur following the passage of a strong midlatitude cyclone in mid- to late August in the northern Rocky Mountains of the United States are recognized in the local culture as the “August Singularity.” Daily standardized maximum temperature anomalies for August–October were examined for eight climate stations in Montana and Idaho as indicators of major midlatitude storms. The data indicate that a single-day negative maximum temperature singularity exists for 13 August. Further, a 3-day singularity event exists for 24–26 August. It is concluded that the concept of an August Singularity in the northern Rockies is valid, because the high frequency of recorded negative maximum temperature anomalies suggests that there are specific time intervals during late summer that are more likely to experience a major midlatitude storm. The principal benefit to society for the August Singularity is that the reduced temperatures help in the efforts to control wildfires that are common this time of year in the northern Rockies.

scholarly journals Future climate uncertainty and spatial variability over Tamilnadu State, India

2015 ◽  
Vol 17 (1) ◽  
pp. 175-185
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Solar Radiation ◽  
Minimum Temperature ◽  
Climate Models ◽  
Regional Climate ◽  
Future Climate ◽  
Maximum Temperature ◽  
Projection Data ◽  
Climate Uncertainty

<div> <p>The present study analyses future climate uncertainty for the 21st century over Tamilnadu state for six weather parameters: solar radiation, maximum temperature, minimum temperature, relative humidity, wind speed and rainfall. The climate projection data was dynamically downscaled using high resolution regional climate models, PRECIS and RegCM4 at 0.22&deg;x0.22&deg; resolution. PRECIS RCM was driven by HadCM3Q ensembles (HQ0, HQ1, HQ3, HQ16) lateral boundary conditions (LBCs) and RegCM4 driven by ECHAM5 LBCs for 130 years (1971-2100). The deviations in weather variables between 2091-2100 decade and the base years (1971-2000) were calculated for all grids of Tamilnadu for ascertaining the uncertainty. These deviations indicated that all model members projected no appreciable difference in relative humidity, wind speed and solar radiation. The temperature (maximum and minimum) however showed a definite increasing trend with 1.8 to 4.0&deg;C and 2.0 to 4.8&deg;C, respectively. The model members for rainfall exhibited a high uncertainty as they projected high negative and positive deviations (-379 to 854 mm). The spatial representation of maximum and minimum temperature indicated a definite rhythm of increment from coastal area to inland. However, variability in projected rainfall was noticed.</p> </div> <p>&nbsp;</p>

scholarly journals Development of 1961-1990 monthly surface climatology of India and patterns of differences of some meteorological parameters with respect to the 1951-1980 climatology

MAUSAM ◽  
2022 ◽  
Vol 63 (3) ◽  
pp. 377-390
Author(s):  
A.K. JASWAL ◽  
S.R. BHAMBAK ◽  
M.K. GUJAR ◽  
S.H. MOHITE ◽  
S. ANANTHARAMAN ◽  
...  
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Spatial Patterns ◽  
Large Scale ◽  
India Meteorological Department ◽  
Cloud Amount ◽  
Climatic Conditions ◽  
Maximum Temperature ◽  
Annual Means ◽  
Rainy Days

Climate normals are used to describe the average climatic conditions of a particular place and are computed by National Meteorological Services of all countries. The World Meteorological Organization (WMO) recommends that all countries prepare climate normals for the 30-year periods ending in 1930, 1960, 1990 and so on, for which the WMO World Climate Normals are published. Recently, Climatological Normals for the period 1961-1990 have been prepared by India Meteorological Department (IMD) which will change the baseline of comparison from 1951-1980. In this paper, preparation of the 30-year Climatological Normals of India for the period 1961 to 1990 and spatial patterns of differences of annual means of temperatures, relative humidity, clouds, rainfall and wind speed from the previous normals (1951-1980) are documented.The changes from earlier climatological normals indicate increase in annual means of maximum temperature, relative humidity and decrease in annual means of minimum temperature, cloud amount, rainfall, rainy days and wind speed over large parts of the country during 1961-1990. The spatial patterns of changes in dry bulb temperatures and relative humidity are complementary over most parts of the country. Compared with 1951-1980 climatology, there are large scale decreases in annual mean rainfall, rainy days and wind speed over most parts of the country during 1961-1990. The decrease in wind speed may be partly due to changes in exposure conditions of observatories due to urbanization.

scholarly journals Long term monthly and inter-seasonal weather variability analysis for the lower Shivalik foothills of Punjab

MAUSAM ◽  
2022 ◽  
Vol 73 (1) ◽  
pp. 173-180
Author(s):  
NAVNEET KAUR ◽  
M.J. SINGH ◽  
SUKHJEET KAUR
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Minimum Temperature ◽  
Maximum Temperature ◽  
Linear Regression Method ◽  
Post Monsoon ◽  
Sunshine Hours ◽  
Annual Minimum Temperature ◽  
Weather Parameters

This paper aims to study the long-term trends in different weather parameters, i.e., temperature, rainfall, rainy days, sunshine hours, evaporation, relative humidity and temperature over Lower Shivalik foothills of Punjab. The daily weather data of about 35 years from agrometeorological observatory of Regional Research Station Ballowal Saunkhri representing Lower Shivalik foothills had been used for trend analysis for kharif (May - October), rabi (November - April), winter (January - February), pre-monsoon (March - May), monsoon (June - September) and post monsoon (October - December) season. The linear regression method has been used to estimate the magnitude of change per year and its coefficient of determination, whose statistical significance was checked by the F test. The annual maximum temperature, morning and evening relative humidity has increased whereas rainfall, evaporation sunshine hours and wind speed has decreased significantly at this region. No significant change in annual minimum temperature and diurnal range has been observed. Monthly maximum temperature revealed significant increase except January, June and December, whereas, monthly minimum temperature increased significantly for February, March and October and decreased for June. Among different seasons, maximum temperature increased significantly for all seasons except winter season, whereas, minimum temperature increased significantly for kharif and post monsoon season only. The evaporation, sunshine hours and wind speed have also decreased and relative humidity decreased significantly at this region. Significant reduction in kharif, monsoon and post monsoon rainfall has been observed at Lower Shivalik foothills. As the region lacks assured irrigation facilities so decreasing rainfall and change in the other weather parameters will have profound effects on the agriculture in this region so there is need to develop climate resilient agricultural technologies.

scholarly journals Effect of meteorological factors on the activity of influenza in Chongqing, China, 2012–2019

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246023
Author(s):  
Li Qi ◽  
Tian Liu ◽  
Yuan Gao ◽  
Dechao Tian ◽  
Wenge Tang ◽  
...  
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Meteorological Factors ◽  
Meteorological Data ◽  
Warning System ◽  
Absolute Humidity ◽  
Influenza Surveillance ◽  
Average Wind Speed ◽  
Mean Temperature ◽  
Influenza Activity

Background The effects of multiple meteorological factors on influenza activity remain unclear in Chongqing, the largest municipality in China. We aimed to fix this gap in this study. Methods Weekly meteorological data and influenza surveillance data in Chongqing were collected from 2012 to 2019. Distributed lag nonlinear models (DLNMs) were conducted to estimate the effects of multiple meteorological factors on influenza activity. Results Inverted J-shaped nonlinear associations between mean temperature, absolute humidity, wind speed, sunshine and influenza activity were found. The relative risks (RRs) of influenza activity increased as weekly average mean temperature fell below 18.18°C, average absolute humidity fell below 12.66 g/m3, average wind speed fell below 1.55 m/s and average sunshine fell below 2.36 hours. Taking the median values as the references, lower temperature, lower absolute humidity and windless could significantly increase the risks of influenza activity and last for 4 weeks. A J-shaped nonlinear association was observed between relative humidity and influenza activity; the risk of influenza activity increased with rising relative humidity with 78.26% as the break point. Taking the median value as the reference, high relative humidity could increase the risk of influenza activity and last for 3 weeks. In addition, we found the relationship between aggregate rainfall and influenza activity could be described with a U-shaped curve. Rainfall effect has significantly higher RR than rainless effect. Conclusions Our study shows that multiple meteorological factors have strong associations with influenza activity in Chongqing, providing evidence for developing a meteorology-based early warning system for influenza to facilitate timely response to upsurge of influenza activity.

scholarly journals Correlation between COVID-19 Morbidity and Mortality Rates in Japan and Local Population Density, Temperature, and Absolute Humidity

2020 ◽  
Vol 17 (15) ◽  
pp. 5477 ◽  
Author(s):  
Sachiko Kodera ◽  
Essam A. Rashed ◽  
Akimasa Hirata
Keyword(s):  
Population Density ◽  
Local Population ◽  
Absolute Humidity ◽  
Mortality Rates ◽  
Morbidity And Mortality ◽  
Maximum Temperature ◽  
Daily Maximum ◽  
P Value ◽  
Nursing Home Patients ◽  
Higher Temperature

This study analyzed the morbidity and mortality rates of the coronavirus disease (COVID-19) pandemic in different prefectures of Japan. Under the constraint that daily maximum confirmed deaths and daily maximum cases should exceed 4 and 10, respectively, 14 prefectures were included, and cofactors affecting the morbidity and mortality rates were evaluated. In particular, the number of confirmed deaths was assessed, excluding cases of nosocomial infections and nursing home patients. The correlations between the morbidity and mortality rates and population density were statistically significant (p-value < 0.05). In addition, the percentage of elderly population was also found to be non-negligible. Among weather parameters, the maximum temperature and absolute humidity averaged over the duration were found to be in modest correlation with the morbidity and mortality rates. Lower morbidity and mortality rates were observed for higher temperature and absolute humidity. Multivariate linear regression considering these factors showed that the adjusted determination coefficient for the confirmed cases was 0.693 in terms of population density, elderly percentage, and maximum absolute humidity (p-value < 0.01). These findings could be useful for intervention planning during future pandemics, including a potential second COVID-19 outbreak.

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