scholarly journals Lyapunov Exponents and Temperature Transitions in a Warming Australia

2019 ◽  
Vol 32 (10) ◽  
pp. 2969-2989 ◽  
Author(s):  
Stephen Gilmore
Keyword(s):  
Lyapunov Exponents ◽  
Heat Waves ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Temperature Record ◽  
Maximum Daily Temperature ◽  
State Variable ◽  
Abrupt Changes ◽  
Maximum Temperatures

Abstract Multiple potential tipping points in the Earth system that involve alternative states have been identified that are susceptible to anthropogenic forcing. Past events—from millions of years ago to within the last century—have manifest as abrupt changes in climatic indicators such as the temperature record. Recent unprecedented heat waves in Australia, their associated devastation, and the considerations above provide motivation to ask whether the Australian daily maximum temperature record has been subject to such abrupt changes. Using a new diagnostic tool—the Lyapunov plot—here it is shown that multiple temperature transitions have occurred with respect to the maximum daily temperature record in widely separated locations in Australia over the last 150 years. All maximum Lyapunov exponents are positive in sign, indicating that the transitions are chaos-to-chaos transitions, and that the different climate modes identified are likely to be manifestations of distinct chaotic attractors. Many of these events occur simultaneously with transitions or extremes in the major natural cycles affecting Australia’s climate, but this observation is not universal. It is known that chaos-to-chaos transitions can result in changes in the value(s) of the state variable(s) that can range from subtle to severe. Although the identified transitions are not catastrophic, this observation does not rule out the possibility of severe, unprecedented, and discontinuous increases in average daily maximum temperatures occurring in Australia at any time within the next few decades.

scholarly journals Temperature-related climate extremes in the Potsdam observation record

Geografie ◽  
2008 ◽  
Vol 113 (4) ◽  
pp. 372-382
Author(s):  
Zbigniew W. Kundzewicz ◽  
Damian Józefczyk
Keyword(s):  
Climate Extremes ◽  
Daily Temperature ◽  
Maximum Temperature ◽  
Daily Minimum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Maximum Daily Temperature ◽  
Daily Minimum ◽  
Maximum Temperatures ◽  
Minimum Daily Temperature

This paper examines temperature-related climate extremes in the unique long-term gapfree record at the Secular Meteorological Station in Potsdam. Increasing tendencies in daily minimum temperature in winter and daily maximum temperature in summer, as well as monthly means of daily minimum temperatures in winter months and of daily maximum temperatures in summer months are illustrated. Also the numbers of hot days and of summer days (with maximum daily temperature exceeding 30 °C and 25 °C, respectively) have been increasing. In agreement with warming of winter minimum temperatures, the numbers of frost days (with minimum daily temperature below 0 °C) and of ice days (with maximum daily temperature below 0 °C) have been decreasing. However, low correlation coefficient and huge scatter illustrate strong natural variability, so that the occurrence of extremes departs from the general underlying tendency.

scholarly journals Assessment of the Environmental and Societal Impacts of the Category-3 Typhoon Hato

Atmosphere ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 296 ◽  
Author(s):  
Eric C. H. Chow ◽  
Min Wen ◽  
Lei Li ◽  
Marco Y. T. Leung ◽  
Paxson K. Y. Cheung ◽  
...  
Keyword(s):  
Hong Kong ◽  
High Temperature ◽  
Air Quality ◽  
Heat Index ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Temperature Record ◽  
Astronomical Tide ◽  
Extreme High Temperature

The destructiveness and potential hazards brought to the Pearl River Delta (PRD) by the category-3 typhoon Hato in 2017 have been studied. The results show that wind flow is one of the key parameters influenced by tropical cyclones. The observed wind at Shenzhen station changed from median southwesterly and calm northerly to strong easterly during the evolution of Hato as it approached the PRD and during landfall, respectively. The peak wind intensity at the surface level and a height of 300 m reached over 17 m s−1 and 30 m s−1, respectively. In Zhuhai, the area closest to the landfall location, the situ observation shows that the maximum wind and the maximum gust on 23 August 2017 reached 29.9 m s−1 and over 50 m s−1, respectively, which is a record-breaking intensity compared with the highest recorded intensity during tropical cyclone (TC) activity in Vicente in 2012. The maximum sea level during 23 August 2017, with an added influence from the storm surge and the astronomical tide, was found to be over 3.9 m to the west of Hong Kong. Extreme high temperature was also recorded on 22 August 2017 before the landfall, with 38.4, 38, and 36.9 °C of daily maximum temperature in Shenzhen, Macao, and Hong Kong, respectively. Based on the heat index calculated with the temperature record at Shenzhen’s station, the hot temperature hazard reached “danger” levels. On the other hand, a prominent air quality deterioration was observed on 21 August 2017. The concentrations rapidly increased to 1 time greater than those on the previous day in Hong Kong. The TC-induced sinking motion, continental advection, and less amount of cloud cover were observed before the landfall, and would be the possible factors causing the extreme high temperature and the poor air quality. This case study illustrates that the influences of Hato to the PRD were not only limited to their destructiveness during landfall, but also brought the extreme high temperature and poor air quality.

Analysis of the extreme heat events in Iran

2017 ◽  
Vol 9 (4) ◽  
pp. 418-432 ◽  
Author(s):  
Hojjatollah Yazdanpanah ◽  
Josef Eitzinger ◽  
Marina Baldi
Keyword(s):  
Trend Analysis ◽  
Heat Wave ◽  
Heat Waves ◽  
Temporal Variations ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Positive Trend ◽  
Content Type ◽  
Hot Days

Purpose The purpose of this paper is to assess the spatial and temporal variations of extreme hot days (H*) and heat wave frequencies across Iran. Design/methodology/approach The authors used daily maximum temperature (Tmax) data of 27 synoptic stations in Iran. These data were standardized using the mean and the standard deviation of each day of the year. An extreme hot day was defined when the Z score of daily maximum temperature of that day was equal or more than a given threshold fixed at 1.7, while a heat wave event was considered to occur when the Z score exceeds the threshold for at least three continuous days. According to these criteria, the annual frequency of extreme hot days and the number of heat waves were determined for all stations. Findings The trend analysis of H* shows a positive trend during the past two decades in Iran, with the maximum number of H* (110 cases) observed in 2010. A significant trend of the number of heat waves per year was also detected during 1991-2013 in all the stations. Overall, results indicate that Iran has experienced heat waves in recent years more often than its long-term average. There will be more frequent and intense hot days and heat waves across Iran until 2050, due to estimated increase of mean air temperature between 0.5-1.1 and 0.8-1.6 degree centigrade for Rcp2.6 and Rcp8.8 scenarios, respectively. Originality/value The trend analysis of hot days and heat wave frequencies is a particularly original aspect of this paper. It is very important for policy- and decision-makers especially in agriculture and health sectors of Iran to make some adaptation strategies for future frequent and intense hot days over Iran.

scholarly journals Responses of Manduca sexta larvae to heat waves

2021 ◽  
pp. jeb.236505
Author(s):  
Joel G. Kingsolver ◽  
M. Elizabeth Moore ◽  
Kate E. Augustine ◽  
Christina A. Hill
Keyword(s):  
Larval Development ◽  
Manduca Sexta ◽  
Growth And Development ◽  
Heat Waves ◽  
Extreme Weather Events ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Developmental Timing ◽  
Daily Maximum ◽  
Experimental Heat

Climate change is increasing the frequency of heat waves and other extreme weather events experienced by organisms. How does the number and developmental timing of heat waves affect survival, growth and development of insects? Do heat waves early in development alter performance later in development? We addressed these questions using experimental heat waves with larvae of the Tobacco Hornworm, Manduca sexta. The experiments used diurnally fluctuating temperature treatments differing in the number (0-3) and developmental timing (early, middle and/or late in larval development) of heat waves, in which a single heat wave involved three consecutive days with a daily maximum temperature of 42 °C. Survival to pupation declines with increasing number of heat waves. Multiple (but not single) heat waves significantly reduced development time and pupal mass; the best models for the data indicated that both the number and developmental timing of heat waves affected performance. In addition, heat waves earlier in development significantly reduced growth and development rates later in larval development. Our results illustrate how the frequency and developmental timing of sublethal heat waves can have important consequences for life history traits in insects.

scholarly journals A Stepwise-Clustered Simulation Approach for Projecting Future Heat Wave Over Guangdong Province

2021 ◽  
Vol 9 ◽  
Author(s):  
Jiayan Ren ◽  
Guohe Huang ◽  
Yongping Li ◽  
Xiong Zhou ◽  
Jinliang Xu ◽  
...  
Keyword(s):  
Heat Wave ◽  
Climate Models ◽  
Extreme Event ◽  
Heat Waves ◽  
Extreme Temperature ◽  
Global Climate Models ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Simulation Approach

A heat wave is an important meteorological extreme event related to global warming, but little is known about the characteristics of future heat waves in Guangdong. Therefore, a stepwise-clustered simulation approach driven by multiple global climate models (i.e., GCMs) is developed for projecting future heat waves over Guangdong under two representative concentration pathways (RCPs). The temporal-spatial variations of four indicators (i.e., intensity, total intensity, frequency, and the longest duration) of projected heat waves, as well as the potential changes in daily maximum temperature (i.e., Tmax) for future (i.e., 2006–2095) and historical (i.e., 1976–2005) periods, were analyzed over Guangdong. The results indicated that Guangdong would endure a notable increasing annual trend in the projected Tmax (i.e., 0.016–0.03°C per year under RCP4.5 and 0.027–0.057°C per year under RCP8.5). Evaluations of the multiple GCMs and their ensemble suggested that the developed approach performed well, and the model ensemble was superior to any single GCM in capturing the features of heat waves. The spatial patterns and interannual trends displayed that Guangdong would undergo serious heat waves in the future. The variations of intensity, total intensity, frequency, and the longest duration of heat wave are likely to exceed 5.4°C per event, 24°C, 25 days, and 4 days in the 2080s under RCP8.5, respectively. Higher variation of those would concentrate in eastern and southwestern Guangdong. It also presented that severe heat waves with stronger intensity, higher frequency, and longer duration would have significant increasing tendencies over all Guangdong, which are expected to increase at a rate of 0.14, 0.83, and 0.21% per year under RCP8.5, respectively. Over 60% of Guangdong would suffer the moderate variation of heat waves to the end of this century under RCP8.5. The findings can provide decision makers with useful information to help mitigate the potential impacts of heat waves on pivotal regions as well as ecosystems that are sensitive to extreme temperature.

Extreme temperatures analysis: A study for Campinas, Brazil

2021 ◽  
Author(s):  
Guilherme Correia ◽  
Ana Maria Ávila
Keyword(s):  
Minimum Temperature ◽  
Temperature Increase ◽  
Heat Waves ◽  
Vulnerable Groups ◽  
Maximum Temperature ◽  
Daily Maximum ◽  
P Value ◽  
Significance Level ◽  
Historical Series ◽  
Maximum Temperatures

<p>Extreme events such as heat waves have adverse effects on human health, especially on vulnerable groups, which can lead to deaths, thus they must be faced as a huge threat. Many studies show general mean temperature increase, notably, minimum temperatures. The scope of this work was to assess daily data of a historical series (1890-2018) available on the Instituto Agronômico de Campinas (IAC), in Campinas, using a suite of indices derived from daily temperature and formulated by the Expert Team on Climate Change Detection and Indices (ETCCDI) and evaluate trends. To compute the extreme indices RClimDex 1.1 was used. The significance test is based on a t  test, with a significance level of 95% (p-value<0,05). Temperature increase is undoubtedly through many indices, especially from 1980, as there is a continuous rise of the temperature. Annual mean maximum temperature rose from 26°C to 29°C, whereas many years consistently have more than 50 days with maximum temperatures as high as 31°C and more than 20% of the days within a year are beyond the 90th percentile of the daily maximum temperatures. Annual mean minimum temperature rose from 14°C to 18°C, whereas many years consistently have more than 150 days with minimum temperatures as high as 18°C and more than 30% of the days within a year are beyond the 90th percentile of the daily minimum temperatures. Therefore, results indicate the increase of minimum temperature is greater than the increase of maximum temperatures.</p>

Seasonal analysis of warm extreme events in Serbia from 1949 to 2017

2020 ◽  
Author(s):  
Ivana Tosic ◽  
Suzana Putniković ◽  
Milica Tošić
Keyword(s):  
Extreme Events ◽  
Heat Waves ◽  
Extreme Temperature ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Extreme Temperature Events ◽  
Air Temperatures ◽  
Seasonal Analysis ◽  
Novi Sad

<p>Worldwide studies revealed a general increase in frequency and severity of warm extreme temperature events. In this study, extreme temperature events including Heat waves (HWs) are examined. Extreme indices are calculated based on daily maximum temperature (Tx). The following definitions are employed: SU - number of days with Tx > 25 °C, umber of days with Tx > 90<sup>th</sup> percentile, and WSDI - number of days in intervals of at least six consecutive days for which Tx is higher than the calendar day 90<sup>th</sup> percentile. Daily values of air temperatures from 11 meteorological stations distributed across Serbia were used for the period 1949–2017.</p><p>Trends of extreme temperature events and their frequencies are examined. The period 1949–2017 are characterised by a warming of extreme temperature indices (SU, Tx90, HWs). It is found that maximum air temperatures increased at all stations, but statistically significant at 6 stations in winter, 4 stations in summer and two stations in spring. The average number of SU per station was between 63.1 in Novi Sad to 73.5 in Negotin during the summer season. Significant increase of SU is recorded in summer for 10 out of 11 stations. Positive trends of SU and Tx90 are observed for all stations and seasons, except in Novi Sad. The average number of Tx90 is about 9 for all stations in all seasons. The longest heat waves prevailed in 2012, but the most severe are recorded in 2007. Increasing of warm extreme events in Serbia are in agreement with studies for different regions of the world.</p>

Effects of patchy shade on stream water temperature: how quickly do small streams heat and cool?

2004 ◽  
Vol 55 (8) ◽  
pp. 737 ◽  
Author(s):  
J. Christopher Rutherford ◽  
Nicholas A. Marsh ◽  
Peter M. Davies ◽  
Stuart E. Bunn
Keyword(s):  
Travel Time ◽  
Dynamic Equilibrium ◽  
Stream Water ◽  
Rate Of Change ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Small Streams ◽  
Maximum Temperatures ◽  
Strong Linear Relationship

Summer field observations in five 2nd order streams (width 1–2 m, depth 5–15 cm, velocity 5–10 cm s–1) in Western Australia and south-east Queensland showed that daily maximum temperatures changed by ±4°C over distances of 600–960 m (travel time 2–3 h) immediately downstream from 40–70% step changes in riparian shade. There was a strong linear relationship between the rate of change of daily maximum temperature and the change of shade such that downstream from a 100% change of shade the heating/cooling rates are ±4°C h–1 and ±10°C km–1 (upper bound ±6°C h–1 and ±15°C km–1) respectively. These high rates only apply over short distances and travel times because downstream water temperatures adjust to the new level of shade and reach a dynamic equilibrium. Shade was too patchy in the study streams to measure how long water takes to reach equilibrium, however, using an existing computer model, we estimate that this occurs after ~1200 m (travel time 4 h). Further modelling work is desirable to predict equilibrium temperatures under given meteorological, flow and shade conditions. Nevertheless, landowners and regulators can use this information to determine whether the presence/absence of certain lengths of bankside shade are likely to cause desirable/undesirable temperature decreases/increases.

Prediction of temperatures in cattle dung for estimating development times of coprophilous organisms

1988 ◽  
Vol 78 (2) ◽  
pp. 235-240 ◽  
Author(s):  
J. N. Matthiessen ◽  
M. J. Palmer
Keyword(s):  
Air Temperature ◽  
Meteorological Data ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Threshold Temperature ◽  
Cattle Dung ◽  
Daily Maximum ◽  
Daily Minimum ◽  
Maximum Temperatures ◽  
Minimum Air Temperature

AbstractIn studies in Western Australia, temperatures in air and one- and two-litre pads of cattle dung set out weekly and ranging from one to 20 days old were measured hourly for 438 days over all seasons, producing 1437 day x dung-pad observations. Daily maximum temperatures (and hence thermal accumulation) in cattle dung pads could not be accurately predicted using meteorological data alone. An accurate predictor of daily maximum dung temperature, using multiple regression analysis, required measurement of the following factors: maximum air temperature, hours of sunshine, rainfall, a seasonal factor (the day number derived from a linear interpolation of day number from day 0 at the winter solstice to day 182 at the preceding and following summer solstices) and a dung-pad age-specific intercept term, giving an equation that explained a 91·4% of the variation in maximum dung temperature. Daily maximum temperature in two-litre dung pads was 0·6°C cooler than in one-litre pads. Daily minimum dung temperature equalled minimum air temperature, and daily minimum dung temperatures occurred at 05.00 h and maximum temperatures at 14.00 h for one-litre and 14.30 h for two-litre pads. Thus, thermal summation in a dung pad above any threshold temperature can be computed using a skewed sine curve fitted to daily minimum air temperature and the calculated maximum dung temperature.

scholarly journals Climate Trends at a Hotspot of Chronic Kidney Disease of Unknown Causes in Nicaragua, 1973–2014

2021 ◽  
Vol 18 (10) ◽  
pp. 5418
Author(s):  
Zoe E. Petropoulos ◽  
Oriana Ramirez-Rubio ◽  
Madeleine K. Scammell ◽  
Rebecca L. Laws ◽  
Damaris Lopez-Pilarte ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Weather Data ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Climate Trends ◽  
Monthly Average ◽  
Weather Stations ◽  
Maximum Temperatures

An ongoing epidemic of chronic kidney disease of uncertain etiology (CKDu) afflicts large parts of Central America and is hypothesized to be linked to heat stress at work. Mortality rates from CKDu appear to have increased dramatically since the 1970s. To explore this relationship, we assessed trends in maximum and minimum temperatures during harvest months between 1973 and 2014 as well as in the number of days during the harvest season for which the maximum temperature surpassed 35 °C. Data were collected at a weather station at a Nicaraguan sugar company where large numbers of workers have been affected by CKDu. Monthly averages of the daily maximum temperatures between 1996 and 2014 were also compared to concurrent weather data from eight Automated Surface Observing System Network weather stations across Nicaragua. Our objectives were to assess changes in temperature across harvest seasons, estimate the number of days that workers were at risk of heat-related illness and compare daily maximum temperatures across various sites in Nicaragua. The monthly average daily maximum temperature during the harvest season increased by 0.7 °C per decade between 1973 and 1990. The number of days per harvest season with a maximum temperature over 35 °C increased by approximately five days per year between 1974 and 1990, from 32 days to 114 days. Between 1991 and 2013, the number of harvest days with a maximum temperature over 35 °C decreased by two days per year, and the monthly average daily maximum temperature decreased by 0.3 °C per decade. Comparisons with weather stations across Nicaragua demonstrate that this company is located in one of the consistently hottest regions of the country.

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