scholarly journals Modeling and projecting health-relevant combined ozone and temperature events in present and future Central European climate

2020 ◽  
Author(s):  
Sally Jahn ◽  
Elke Hertig
Keyword(s):  
Large Scale ◽  
Time Windows ◽  
Coupled Model ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Pollution Levels ◽  
European Climate ◽  
Air Temperatures ◽  
Meridional Winds

Abstract Statistical models to evaluate the relationships between large-scale meteorological conditions, prevailing air pollution levels and combined ozone and temperature events, were developed during the 1993–2012 period with Central Europe as regional focus. Combined ozone and temperature events were defined based on the high frequency of coinciding, health-relevant elevated levels of daily maximum tropospheric ozone concentrations (based on running 8-h means) and daily maximum temperature values in the peak ozone and temperature season from April to September. By applying two different modeling approaches based on lasso, logistic regression, and multiple linear regression mean air temperatures at 850 hPa, ozone persistence, surface thermal radiation, geopotential heights at 850 hPa, meridional winds at 500 hPa, and relative humidity at 500 hPa were identified as main drivers of combined ozone and temperature events. Statistical downscaling projections until the end of the twenty-first century were assessed by using the output of seven models of the Coupled Model Intercomparison Project Phase 5 (CMIP5). Potential frequency shifts were evaluated by comparing the mid- (2031–2050) and late-century (2081–2100) time windows to the base period (1993–2012). A sharp increase of ozone-temperature events was projected under RCP4.5 and RCP8.5 scenario assumptions with respective multi-model mean changes of 8.94% and 16.84% as well as 13.33% and 37.52% for mid- and late-century European climate.

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>

UK Climate Projections 2018 (UKCP18): progress towards more information on future weather

2020 ◽  
Author(s):  
David Sexton ◽  
Jason Lowe ◽  
James Murphy ◽  
Glen Harris ◽  
Elizabeth Kendon ◽  
...  
Keyword(s):  
Large Scale ◽  
Future Climate ◽  
Maximum Temperature ◽  
Cmip5 Models ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Climate Projections ◽  
Circulation Index ◽  
Large Contribution ◽  
Probabilistic Projections

<p>UK Climate Projections 2018 (UKCP18) included land and marine projections and were published in 2018 to replace UKCP09. The land projections had three components, and all were designed to provide more information on future weather compared to UKCP09. The first component updated the UKCP09 probabilistic projections by including newer CMIP5 data and focussing on seasonal means from individual years rather than 30-year averages. The probabilistic projections represent the wider uncertainty. The second two components (global and regional projections) both had the aim of providing plausible examples of future climate, but at different resolutions.</p><p>The global projections were a combination of 13 CMIP5 models and a 15-member perturbed parameter ensemble (PPE) of coupled simulations for 1900-2100 using CMIP5 RCP8.5 from 2005 onwards. The PPE was provided at 60km atmosphere, quarter degree ocean and the large-scale conditions from twelve of the members were used to drive the regional model at both 12km and 2.2km resolution. These plausible examples are more useful for providing information about weather in a future climate to support a storyline approach for decision making.</p><p>The talk will present examples of new ways to use UKCP18 compared to UKCP09.  We will show how the global projections can be used to understand that the recent record winter daily maximum temperature in the UK in 2019 had a large contribution from internal variability and what this means for breaking the record in a warming climate. We also use an example from China to demonstrate one way to exploit information at different time scales, looking at how a circulation index, which is predictable and related to tropical cyclone landfall, changes in a future climate.</p><p>Finally, we show that while the enhanced resolution of the global and regional projections has improved our capability to provide climate information linked to the better representation of circulation, they lack diversity in some of the key drivers of future climate. Therefore, a key way forward will be to find an appropriate balance between the need for better diversity (e.g. multiple ensembles such as CMIP or PPEs) and the need for an appropriate resolution to retain this new capability.</p>

Influence of High-Temperatures on the Survival of Rhopalosiphum-Padi (L) (Hemiptera, Aphididae) in Irrigated Perennial Grass Pastures in South-Australia

1993 ◽  
Vol 41 (2) ◽  
pp. 123 ◽  
Author(s):  
PJ Debarro ◽  
DA Maelzer
Keyword(s):  
Field Experiment ◽  
Rhopalosiphum Padi ◽  
Perennial Grass ◽  
South Australia ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Air Temperatures ◽  
Exposure Temperature ◽  
C 32

A field experiment in a perennial grass pasture showed that the survival of Rhopalosiphum padi (L.) (Hemiptera: Aphididae) was reduced when aphids were exposed to air temperatures of at least 36-degrees-C (32-degrees-C at the base of the sward). The longevity, rate of reproduction and fecundity of individuals also declined as the exposure temperature and duration of exposure increased. The results of the field experiment were later corroborated by sampling an aphid population every 4-6 days over summer and regressing aphid numbers on daily maximum temperature and duration of exposure to temperature. A model is proposed to estimate the numbers of aphids that survive in refuge areas over summer in relation to temperature-induced mortality.

scholarly journals Evaluation of Historical CMIP6 Model Simulations and Future Projections of Temperature Over the Pan-Third Pole Region

2021 ◽  
Author(s):  
Xuewei Fan ◽  
Qingyun Duan ◽  
Chenwei Shen ◽  
Yi Wu ◽  
Chang Xing
Keyword(s):  
Tibetan Plateau ◽  
Coupled Model ◽  
Temporal Variations ◽  
Maximum Temperature ◽  
Daily Minimum Temperature ◽  
Daily Maximum Temperature ◽  
Strong Increase ◽  
Daily Maximum ◽  
The Tibetan Plateau ◽  
Extreme Temperatures

Abstract The Pan-Third Pole (PTP) region, which encompasses the Eurasian highlands and their surroundings, has experienced unprecedented, accelerated warming during the past decades. This study evaluates the performance of historical simulation runs of the Coupled Model Intercomparison Project (CMIP6) in capturing spatial patterns and temporal variations observed over the PTP region for mean and extreme temperatures. In addition, projected changes in temperatures under four Shared Socioeconomic Pathway (SSP) scenarios (SSP1-2.6, SSP2‐4.5, SSP3-7.0, and SSP5‐8.5) are also reported. Four indices were used to characterize changes in temperature extremes: the annual maximum value of daily maximum temperature (TXx), the annual minimum value of daily minimum temperature (TNn), and indices for the percentage of warm days (TX90p) and warm nights (TN90p). Results indicate that most CMIP6 models generally capture the characteristics of the observed mean and extreme temperatures over the PTP region, but there still are slight cold biases in the Tibetan Plateau. Future changes of mean and extreme temperatures demonstrate that a strong increase will occur for the entire PTP region during the twenty-first century under all four SSP scenarios. Between 2015 and 2099, ensemble area-averaged annual mean temperatures are projected to increase by 1.24°C/100 year, 3.28°C/100 year, 5.57°C/100 year, and 7.40°C/100 year for the SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5 scenarios, respectively. For TXx and TNn, the most intense warming is projected in Central Asia. The greatest number of projected TX90p and TN90p will occur in the Tibetan Plateau and Southeast Asia subregions, respectively.

scholarly journals Attributing trends in extremely hot days to changes in atmospheric dynamics

2015 ◽  
Vol 3 (5) ◽  
pp. 3323-3367
Author(s):  
J. A. García-Valero ◽  
J. P. Montávez ◽  
J. J. Gómez-Navarro ◽  
P. Jiménez-Guerrero
Keyword(s):  
Large Scale ◽  
Atmospheric Dynamics ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Sea Level Pressure ◽  
Circulation Types ◽  
Hot Days ◽  
The One ◽  
Atmospheric Variables

Abstract. This paper proposes a method that allows the detection of trends in the frequency of extreme events and its attribution to changes in atmospheric dynamics characterized through Circulation Types (CTs). The method is applied to summer Extremely Hot Days (EHD) in Spain during the period 1958–2008. For carrying out this exercise, regional series of daily maximum temperature are derived from the regional dataset Spain02. Eight regions with different daily maximum temperature variability are identified. All of them exhibit important trends in the occurrence of EHDs, especially in inner regions. Links between the probability of EHD occurrence in the regions and CTs have been calculated. Furthermore, the consistency of the results to the atmospheric variables used in defining the CTs is analyzed. Sea Level Pressure (SLP), Temperature at 850 hPa Level (T850) and Geopotential Height at 500 hPa Level (Z500) from the ERA40 dataset have been used for the six CT classifications obtained using the variables separately and in different combinations of pairs. The optimum choice of large scale variables depends on the region under consideration, being the combination SLP-T850 the one giving the most suitable characterization for most of them. Finally, an attribution exercise of the regional EHD trends to the dynamics is proposed. Results show that the maximum of attributable EHD trends to changes in dynamics in every region is always below 5 %, being even lower than 20% in those regions with the largest EHD trends, mainly located in the center of the Iberian Peninsula (IP).

Rapid Local Urbanization around Most Meteorological Stations Explains the Observed Daily Asymmetric Warming Rates across China from 1985 to 2017

2020 ◽  
Vol 33 (20) ◽  
pp. 9045-9061 ◽  
Author(s):  
Shaojing Jiang ◽  
Kaicun Wang ◽  
Yuna Mao
Keyword(s):  
Large Scale ◽  
Maximum Temperature ◽  
Daily Minimum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Surface Solar Radiation ◽  
Land Cover Data ◽  
Warming Rate ◽  
Observational Bias ◽  
Weather Stations

AbstractThe increasing rate of the observed daily minimum temperature Tmin has been much higher than that of the observed daily maximum temperature Tmax during the past six decades across China. In this study, the local urbanization impact on these observed asymmetric warming rates was investigated. The latest released land-cover data with a 30-m spatial resolution and annual temporal resolution from 1985 to 2017 were used to quantify the urbanization ratios around weather stations. Although urbanized areas occupied only 2.25% of the landmass in China, the percentage of stations with an urbanization ratio over 20% increased from 22.1% to 68.2% during the period 1985–2017. Significant asymmetric warming rates at urban stations were identified, which were approximately 3 times larger compared to the average asymmetry observed at all 2454 stations in China. However, this asymmetry disappeared at rural stations. These differences are mainly due to the rapid local urbanization around most meteorological stations in China since 1985, which affected the spatial representation of observations and led to the observed asymmetry warming rates. The results reported here indicate that the observed asymmetric warming rate over China from 1985 to 2017 is an observational bias due to local urbanization around most stations rather than large-scale climate change. The results also explain the phenomenon that the observed warming rate of Tmin remains higher than that of Tmax after 1990 when the surface solar radiation stops decreasing in China.

A TECHNIQUE FOR ESTIMATING HATCHING OF NATURAL EGG POPULATIONS OF MELANOPLUS SANGUINIPES (ORTHOPTERA: ACRIDIDAE)

1974 ◽  
Vol 106 (8) ◽  
pp. 801-812 ◽  
Author(s):  
R. L. Randell ◽  
M. K. Mukerji
Keyword(s):  
Embryonic Development ◽  
Control Measures ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Melanoplus Sanguinipes ◽  
Average Effect ◽  
Spring Temperature ◽  
Hatching Time ◽  
Air Temperatures

AbstractThe earliness or lateness of the hatching period in Melanoplus sanguinipes (Fabr.) affects the type and amount of damage to the crop and the timing of control measures. An empirical model for prediction of hatching at each decile of egg populations was developed by multiple regression using daily maximum air temperatures for a unit interval of 5 days from 2 March to 29 June and embryonic development in the preceding fall. The model accounted for a maximum of 96% of the variance in hatching date. It showed the average effect of a unit change of 1° of daily maximum temperature for each of the 24 5-day intervals on the number of days to hatch. The time and pattern of hatching of the major bulk of egg population was dependent mainly on spring temperature; however, fall embryonic development accounted for considerable variation in hatching time especially of the less developed eggs. The implications for population growth and certain assumptions made during the analyses in this study are discussed.

scholarly journals Downscaling probability of long heatwaves based on seasonal mean daily maximum temperatures

2018 ◽  
Vol 4 (1/2) ◽  
pp. 37-52
Author(s):  
Rasmus E. Benestad ◽  
Bob van Oort ◽  
Flavio Justino ◽  
Frode Stordal ◽  
Kajsa M. Parding ◽  
...  
Keyword(s):  
Climate Models ◽  
Global Climate ◽  
Coupled Model ◽  
Principal Component ◽  
Global Climate Models ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Climate Conditions ◽  
Probability Of Occurrence

Abstract. A methodology for estimating and downscaling the probability associated with the duration of heatwaves is presented and applied as a case study for Indian wheat crops. These probability estimates make use of empirical-statistical downscaling and statistical modelling of probability of occurrence and streak length statistics, and we present projections based on large multi-model ensembles of global climate models from the Coupled Model Intercomparison Project Phase 5 and three different emissions scenarios: Representative Concentration Pathways (RCPs) 2.6, 4.5, and 8.5. Our objective was to estimate the probabilities for heatwaves with more than 5 consecutive days with daily maximum temperature above 35 ∘C, which represent a condition that limits wheat yields. Such heatwaves are already quite frequent under current climate conditions, and downscaled estimates of the probability of occurrence in 2010 is in the range of 20 %–84 % depending on the location. For the year 2100, the high-emission scenario RCP8.5 suggests more frequent occurrences, with a probability in the range of 36 %–88 %. Our results also point to increased probabilities for a hot day to turn into a heatwave lasting more than 5 days, from roughly 8 %–20 % at present to 9 %–23 % in 2100 assuming future emissions according to the RCP8.5 scenario; however, these estimates were to a greater extent subject to systematic biases. We also demonstrate a downscaling methodology based on principal component analysis that can produce reasonable results even when the data are sparse with variable quality.

scholarly journals Elevation Effects on Air Temperature in a Topographically Complex Mountain Valley in the Spanish Pyrenees

Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 656
Author(s):  
Francisco Navarro-Serrano ◽  
Juan Ignacio López-Moreno ◽  
Cesar Azorin-Molina ◽  
Esteban Alonso-González ◽  
Marina Aznarez-Balta ◽  
...  
Keyword(s):  
Air Temperature ◽  
Weather Conditions ◽  
Time Lapse ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Night Time ◽  
Air Temperatures ◽  
Spanish Pyrenees ◽  
Lapse Rates

Air temperature changes as a function of elevation were analyzed in a valley of the Spanish Pyrenees. We analyzed insolation, topography and meteorological conditions in order to understand how complex topoclimatic environments develop. Clustering techniques were used to define vertical patterns of air temperature covering more than 1000 m of vertical elevation change. Ten locations from the bottom of the valley to the summits were monitored from September 2016 to June 2019. The results show that (i) night-time lapse rates were between −4 and −2 °C km−1, while in the daytime they were from −6 to −4 °C km−1, due to temperature inversions and topography. Daily maximum temperature lapse rates were steeper from March to July, and daily minimum temperatures were weaker from June to August, and in December. (ii) Different insolation exposure within and between the two analyzed slopes strongly influenced diurnal air temperatures, creating deviations from the general lapse rates. (iii) Usually, two cluster patterns were found (i.e., weak and steep), which were associated with stable and unstable weather conditions, respectively, in addition to high-low atmospheric pressure and low-high relative humidity. The results will have direct applications in disciplines that depend on air temperature estimations (e.g., snow studies, water resources and sky tourism, among others).

scholarly journals Evaluation of historical CMIP6 model simulations and future projections of temperature over the Pan-Third Pole region

2021 ◽  
Author(s):  
Xuewei Fan ◽  
Qingyun Duan ◽  
Chenwei Shen ◽  
Yi Wu ◽  
Chang Xing
Keyword(s):  
Tibetan Plateau ◽  
Coupled Model ◽  
Temporal Variations ◽  
Maximum Temperature ◽  
Daily Minimum Temperature ◽  
Daily Maximum Temperature ◽  
Strong Increase ◽  
Daily Maximum ◽  
The Tibetan Plateau ◽  
Extreme Temperatures

AbstractThe Pan-Third Pole (PTP) region, which encompasses the Eurasian highlands and their surroundings, has experienced unprecedented, accelerated warming during the past decades. This study evaluates the performance of historical simulation runs of the Coupled Model Intercomparison Project (CMIP6) in capturing spatial patterns and temporal variations observed over the PTP region for mean and extreme temperatures. In addition, projected changes in temperatures under four Shared Socioeconomic Pathway (SSP) scenarios (SSP1‐2.6, SSP2‐4.5, SSP3-7.0, and SSP5‐8.5) are also reported. Four indices were used to characterize changes in temperature extremes: the annual maximum value of daily maximum temperature (TXx), the annual minimum value of daily minimum temperature (TNn), and indices for the percentage of warm days (TX90p) and warm nights (TN90p). Results indicate that most CMIP6 models generally capture the characteristics of the observed mean and extreme temperatures over the PTP region, but there still are slight cold biases in the Tibetan Plateau. Future changes of mean and extreme temperatures demonstrate that a strong increase will occur for the entire PTP region during the twenty-first century under all four SSP scenarios. Between 2015 and 2099, ensemble area-averaged annual mean temperatures are projected to increase by 1.24 °C/100 year, 3.28 °C/100 year, 5.57 °C/100 year, and 7.40 °C/100 year for the SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5 scenarios, respectively. For TXx and TNn, the most intense warming is projected in Central Asia. The greatest number of projected TX90p and TN90p will occur in the Southeast Asia and Tibetan Plateau, respectively.

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