The multiscale organization of moist convection and the intersection of weather and climate

Author(s):  
Mitchell W. Moncrieff
2016 ◽  
Vol 9 (9) ◽  
pp. 3393-3412 ◽  
Author(s):  
David Leutwyler ◽  
Oliver Fuhrer ◽  
Xavier Lapillonne ◽  
Daniel Lüthi ◽  
Christoph Schär

Abstract. The representation of moist convection in climate models represents a major challenge, due to the small scales involved. Using horizontal grid spacings of O(1km), convection-resolving weather and climate models allows one to explicitly resolve deep convection. However, due to their extremely demanding computational requirements, they have so far been limited to short simulations and/or small computational domains. Innovations in supercomputing have led to new hybrid node designs, mixing conventional multi-core hardware and accelerators such as graphics processing units (GPUs). One of the first atmospheric models that has been fully ported to these architectures is the COSMO (Consortium for Small-scale Modeling) model.Here we present the convection-resolving COSMO model on continental scales using a version of the model capable of using GPU accelerators. The verification of a week-long simulation containing winter storm Kyrill shows that, for this case, convection-parameterizing simulations and convection-resolving simulations agree well. Furthermore, we demonstrate the applicability of the approach to longer simulations by conducting a 3-month-long simulation of the summer season 2006. Its results corroborate the findings found on smaller domains such as more credible representation of the diurnal cycle of precipitation in convection-resolving models and a tendency to produce more intensive hourly precipitation events. Both simulations also show how the approach allows for the representation of interactions between synoptic-scale and meso-scale atmospheric circulations at scales ranging from 1000 to 10 km. This includes the formation of sharp cold frontal structures, convection embedded in fronts and small eddies, or the formation and organization of propagating cold pools. Finally, we assess the performance gain from using heterogeneous hardware equipped with GPUs relative to multi-core hardware. With the COSMO model, we now use a weather and climate model that has all the necessary modules required for real-case convection-resolving regional climate simulations on GPUs.


Author(s):  
A.I. Ivanov ◽  
Zh.A. Ivanova ◽  
O.I. Yakusheva ◽  
P.A. Filippov

Целью комплексного исследования, выполненного в Меньковском филиале АФИ в 20122017 годах была оценка вредоносности возбудителя фитофтороза в зависимости от почвенноагрохимических и погодноклиматических условий. Методической основой исследования служил длительный полевой опыт агрофизический стационар в системе полевого и овощекормового севооборотов, в которых картофель возделывали по обороту пласта многолетних трав после озимой ржи и после ячменя. Объектами исследования служили: картофель раннеспелого сорта Ломоносовский среднеустойчивого к возбудителю фитофтороза по клубням и слабоустойчивого по ботве дерновоподзолистая почва средней, хорошей и высокой степени окультуренности и системы удобрения культуры. Супесчаная почва опыта характеризовалась рНКСl 5,26,3, содержанием гумуса 2,13,7, подвижных соединений P2О5 195676 мг/кг и К2О 97298 мг/кг. На хорошо окультуренной и высокоокультуренной почвах их поддерживали применением под картофель 35 и 70 т/га органических удобрений соответственно. Факторы исследования: степень окультуренности почвы (варианты: средняя, хорошая и высокая) и уровень применения минеральных удобрений в расчете на заданный КПД (коэффициент полезного действия фотосинтетически активной радиации) (варианты: КПД ФАР, 13 без удобрений КПД ФАР, 24 N80P20K100 КПД ФАР, 35 N120P30K150). В ходе комплексного исследования установлены параметры поражения возбудителем фитофтороза и уровень потерь урожая картофеля в зависимости от агроклиматических и почвенноагрохимических условий. Агрономическая эффективность изученных вариантов системы удобрения на культуре картофеля высокая. Уровень прибавок урожайности клубней и окупаемость 1 кг д.в. удобрений достигли 3358 и 8,311,6 з.ед. (зерновых единиц) на минеральной, 2545 и 3,98,0 з.ед. на органической и 3379 и 3,86,7 з.ед. на органоминеральной системе удобрения. В неэпифитотийных условиях (2 из 3 лет наблюдений) на фоне низких и умеренных показателей поражения общие потери урожая составляют 5, а окультуривание почвы и применение органических и минеральных удобрений снижают их на 3080. На эпифитотийном фоне, повторяющемся 1 раз в 3 года, пораженность ботвы и клубней картофеля возрастает в 4,3 и 6,1, интенсивность поражения в 2,8 и 3 и развитие в 12 и 17,5 раза соответственно. В эпифитотийные годы потери урожая возрастают в 5,2 раза (до 26), а минеральная система удобрения сокращает их только на среднеокультуренной почве. На этом фоне повышение степени окультуренности почвы и доз органических удобрений до высокого уровня неэффективно.Late blight is one of the most harmful potato diseases in the NorthWest of Russia. Today, its negative effects are aggravated by weather and climate changes. The goal of a comprehensive study carried out in the Menkovsky branch of the Agrophysical Institute in 2012 2017 was an assessment of the harmfulness of the late blight pathogen depending on soilagrochemical, weather and climate conditions. The methodical basis of the research was a prolonged field agrophysical stationary experiment in the system of field and vegetablefeed crop rotations, where potato was cultivated after winter rye and after barley, which, in turn, were grown after perennial grasses. The objects of the study were potato Lomonosovsky, sodpodzolic soil with different degree of cultivation and fertilizer systems for the culture. Potato Lomonosovsky is early ripening variety, its tubers are medium resistant to the late blight agent, and its tops are weakly resistant to it. The sodpodzolic soil had average, good and high cultivation degree. Sandy loam soil in the experiment had the value of pHKCl of 5.2 6.3, the humus content of 2.1 3.7, the content of mobile P2O5 and K2O compounds of 195 676, 97 298 mg/kg, respectively. In well and highly cultivated soils, these parameters were maintained by the application of 35 and 70 t/ha of organic fertilizers for potato, respectively. The experimental factors were the degree of soil cultivation (average, good and high) and the level of mineral fertilizer application for a given efficiency of photosynthetically active radiation (PAR efficiency of 1 3, without fertilizers PAR efficiency of 2 4, N80P20K100 PAR efficiency of 3 5, N120P30K150). In the course of the comprehensive study, the parameters of potato damage by late blight and the level of crop losses were established depending on the agroclimatic soilagrochemical conditions. Agronomic efficiency of the studied variants of the fertilizer system for potato was high. The level of tuber yield increase and payback of 1 kg of fertilizers active substances reached 33 58 and 8.3 11.6 cereal units (CU) for the mineral system, 25 45 and 3.9 8.0 CU for the organic one, and 33 79 and 3.8 6.7 CU for the organic and mineral fertilizer system. Under nonepiphytotic conditions (2 of 3 years of the observation), against the background of low and moderate damage rates, the total yield loss was 5, and the soil improvement and organic and mineral fertilizer application reduced them by 30 80. Against an epiphytotic background, repeated 1 time in 3 years, the damage of tops and potato tubers increases by a factor of 4.3 and 6.1, the intensity of the damage grew 2.8 and 3 times, and the development increases by a factor of 12 and 17.5 times, respectively. In the epiphytotic years, yield losses increased 5.2 times (up to 26), and the mineral fertilizer system reduced them only in medium cultured soil. Against this background, increasing the soil cultivation degree and organic fertilizer doses to a high level is ineffective.


Sign in / Sign up

Export Citation Format

Share Document