Heat and Cold Wave

AccuWeather site: "Heat waves can occur when a high pressure system enters a region and stagnates. The system can force warm air downward preventing the cool air at the surface from rising."
What constitutes a heat wave can vary greatly from region to region. So let's analyze what happened in
the Moscow region this summer (2021) regarding the heat wave using the discontinuous-physics
approach.

The consequences of raising temperatures have been intensively studied by biologists and ecologists for the past few decades. However, current climatic changes also include many anomalous weather events, such as intraseasonal heatwaves followed by immediate decreases in temperature. In this study, the responses of population development and life history traits to different thermal regimes were investigated. The freshwater water flea Daphnia magna (Cladocera, Crustacea) was used as a model organism. Daphnia magna populations were monitored
under temperature regimes of warm (25 °C), cold (5 °C), synchronous (gradual changes between 25 °C and 5 °C) or stochastic (random changes between 25 °C and 5 °C). Population size of D. magna populations decreased with unpredictability of thermal conditions; the highest density of D. magna was found in the warm environment
and the lowest density in the stochastic environment. Thermal regime had significant impact on the prevalence of asexual and sexual reproduction of D. magna. Under a synchronous regime, an accumulation of asexual reproduction was observed during cold episodes; thiswas followed by a phase of population disturbance,
manifesting itself in high fluctuations of asexual reproduction and a pattern of sexual reproduction typical of a cold regime. Under a stochastic regime, the population disturbances were observed throughout the duration of the experiment. Daily observations of individual life history traits revealed that the development of populations
under different thermal regimes resulted from the regime-specific survivability of neonates. Population development was also affected by the frequency of reproduction, which consisted of the number of broods carried per lifetime. The results indicate that not only temperature but also shifts in thermal conditions have an important influence on individual life history traits and population dynamics of D. magna. It is important to consider theeffects of shifts inwater temperature on demographic and individual traits simultaneously because the impact of
thermal changes on population traits can be modified by individual life histories.

INTRODUCTION: Mortality is associated with daily temperatures and extreme cold events. This study aimed to analyze the effects of low temperatures on mortality in the main urban areas of Argentina during 2005-2015. METHODS: A time-series study with generalized additive models was conducted, modeling the relationship between low temperatures and mortality for 21 cities in Argentina between 2005 and 2015. Total mortality was analyzed as well as mortality by sex, age and cause of death, considering cold days, cold spells and delays of 7 and 14 days after those events. RESULTS: Within a 7-day lag, the risk of death increases for a cold day in half of the cities analyzed between 1.04 [CI95%: 1.00-1.08] and 1.14 [CI95%: 1.06-1.23]. The most vulnerable group was people aged 65 or more years, with increases of up to 1.20 [CI95%: 1.05-1.39]. Cold spells are associated with an increased risk within the subsequent 7 days in 8 cities (1.05 [CI95%: 1.03-1.08] to 1.30 [CI95%: 1.03-1.65]), which increases to 10 cities for the 14-day lag, with slightly lower values. CONCLUSIONS: With differences in magnitude and statistical robustness by cities, the population of most urban areas presents an increased risk of death within 7 and 14 days after an event of extreme cold. RESUMEN. INTRODUCCIÓN: La mortalidad guarda relación con las temperaturas diarias y los eventos extremos. Este estudio buscó analizar los efectos de las bajas temperaturas sobre la mortalidad en las principales ciudades de Argentina en el período 2005-2015. MÉTODOS: Se realizó un estudio de series temporales con modelos aditivos generalizados, modelando la relación entre bajas temperaturas y mortalidad para 21 ciudades de Argentina entre 2005 y 2015. Se analizó la mortalidad general y por grupos de sexo, edad y causa de muerte, en días fríos y días de olas de frío, así como los rezagos de 7 y 14 días posteriores a dichos eventos. RESULTADOS: En los 7 días posteriores a un día frío, el riesgo de muerte aumenta en la mitad de las ciudades entre un 1,04 [IC95%: 1,00-1,08] y un 1,14 [IC95%: 1,06-1,23] según la ciudad. El grupo de 65 años y más es el que muestra mayor impacto, con un incremento de hasta el 1,20 [IC95%: 1,05-1,39]. Las olas de frío se asocian con un aumento más pronunciado en el riesgo de morir en los siguientes 7 días en 8 ciudades (1,05 [IC95%: 1,03-1,08] a 1,30 [IC95%: 1,03-1,65]), y en 10 ciudades en los siguientes 14 días, aunque con valores algo más bajos. CONCLUSIONES: Con diferencias en magnitud y robustez estadística según las ciudades, la población de las áreas urbanas presenta un riesgo aumentado de muerte durante los 7 y 14 días posteriores a un evento de frío extremo.

Global average temperatures increased by 0.8°C in 2016 as compared to the period of 1961-1990 and 1.1°C from the pre-industrial period (1850-1899).They hit records for three consecutive years in 2014, 2015 and 2016, and the year 2016 ranks as the warmest on record. Climate models expect a temperature increase between 1.5°C-2.5°C and between 2.5°C-3.6°C based on RCP4.5 and RCP8.5 scenarios respectively by end of the century. It is projected that the increased temperatures may cause increases in the frequency and severity of some meteorological extreme events. Heat waves accounted for 43% of meteorological disasters in 2016 in Turkey. In this study, future trends of periods of heat and cold waves are studied with respect to RCP4.5 and RCP8.5 scenarios of HadGEM2-ES Global Climate Model. The results showed while number of heat waves are expected to increase, a decreasing trend of cold waves will dominate in future periods in Turkey.