Evaporation of stratiform precipitation and its temperature response in idealized WRF simulations

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientific

Abstract

Atmospheric deep convection produces most of the precipitation on Earth and is the main mechanism for precipitation in the tropics. Moreover, convection in the tropics can a↵ect large-scale weather patterns in Europe (Harnik et al. 2014) and a link exists between weather conditions over Europe simulated by the Integrated Forecast System and the representation of convection in the tropics (Vitart and Molteni, 2010).

Deep convection often occurs as single cells on horizontal scale of less than 10 km, but the anvils of individual deep convective cells frequently merge and form large mesoscale convective systems (MCS) with areas sometimes exceeding 40 000 km2 (Mohr and Zipser, 1996). In addition to MCSs producing intense deep convective precipitation, stratiform precipitation from the anvils of deep convection contributes to roughly 30-50 percent of the total rain amount associated with MCSs (see e.g. Tokay and Short, 1996, and references therein).

Humidity just above the boundary layer is known to control atmospheric deep convection, especially in the tropics (e.g. Bretherton et al. 2004; Sobel et al. 2004). Entrainment of environmental air into the cloudy updrafts is often suggested as the reason for this sensitivity (Holloway and Neelin, 2009; Schiro et al. 2016). However, Virman et al. (2018) propose a new mechanism to explain why moist air just above the boundary layer favours deep convection. Based on an analysis of radiosonde observations over tropical oceans, they suggest that evaporation of stratiform precipitation associated with MCSs can produce warm anomalies just above the boundary layer, thus inhibiting subsequent deep convection.

Modeling studies are needed as then it is possible to isolate the e↵ects of evaporation of stratiform precipitation among the many other physical processes occurring with MCSs. As a first step to quantify how evaporation of stratiform precipitation a↵ects the vertical profile of temperature, we have conducted high resolution simulations of stratiform precipitation.
Original languageEnglish
Title of host publicationProceedings of ‘The Centre of Excellence in Atmospheric Science (CoE ATM) : 'From Molecular and Biological processes to The Global Climate’, Annual Meeting 2018
EditorsPäivi Haapanala, Anna Lintunen, Joonas Enroth, Markku Kulmala
Number of pages4
Place of PublicationHelsinki
PublisherAerosolitutkimusseura ry – Finnish Association for Aerosol Research FAAR
Publication date2018
Pages490-493
ISBN (Print)978-952-7276-11-2
Publication statusPublished - 2018
MoE publication typeB3 Article in conference proceedings
EventThe Centre of Excellence in Atmospheric Science (CoE ATM) – From Molecular and Biological processes to The Global Climate’ Annual Meeting - Kuopio, Kuopio, Finland
Duration: 27 Nov 201829 Nov 2018

Publication series

NameReport Series in Aerosol Science
PublisherAerosolitutkimusseura ry
Number215
ISSN (Print)0784-3496

Fields of Science

  • 114 Physical sciences
  • 1172 Environmental sciences

Cite this

Virman, M., Bister, M., Sinclair, V. A., Räisänen, J., & Järvinen, H. (2018). Evaporation of stratiform precipitation and its temperature response in idealized WRF simulations. In P. Haapanala, A. Lintunen, J. Enroth, & M. Kulmala (Eds.), Proceedings of ‘The Centre of Excellence in Atmospheric Science (CoE ATM): 'From Molecular and Biological processes to The Global Climate’, Annual Meeting 2018 (pp. 490-493). (Report Series in Aerosol Science ; No. 215). Aerosolitutkimusseura ry – Finnish Association for Aerosol Research FAAR.