Precipitation

About: Precipitation is a research topic. Over the lifetime, 32861 publications have been published within this topic receiving 990496 citations. The topic is also known as: rain & rainfall.

Quantifying the Relevance of Cyclones for Precipitation Extremes

Abstract: Owing to the huge potential impact of precipitation extremes on society, it is important to better understand the mechanisms causing these events, and their variations with respect to a changing climate. In this study, the importance of a particular category of weather systems, namely cyclones, for the occurrence of regional-scale precipitation extremes is quantified globally using the ECMWF Interim reanalysis (ERA-Interim) dataset. Such an event-based climatological approach complements previous case studies, which established the physical relationship between cyclones and heavy precipitation. A high percentage of precipitation extremes is found to be directly related to cyclones. Regional hot spots are identified where this percentage of cyclone-induced precipitation extremes exceeds 80% (e.g., in the Mediterranean region, Newfoundland, near Japan, and over the South China Sea). The results suggest that in these regions changes of heavy precipitation with global warming are specifically sensitiv...

Variability of Southwest Indian summer monsoon precipitation during the Bølling-Ållerød

Abstract: We have generated a high-resolution (<20 yr) 2 3 0 Th-dated stalagmite oxygen isotope record from Timta Cave in the western Himalaya in India that documents Southwest Indian summer monsoon (ISM) precipitation variations during the Bolling-Allerod interstadial from 15.2 to 11.7 ka. Compared with the glacial and Younger Dryas, ISM precipitation was enhanced during the Bolling-Allerod. ISM precipitation was apparently coupled to variations in the East Asian monsoon and North Atlantic climate on millennial and multicentennial time scales during the deglaciation. Analyses of a high growth rate interval (<2.5 yr resolution) encompassing the late Bolling-early Alterod suggest that multidecadal monsoon variability was an important aspect of ISM behavior at that time. The frequency spectrum of ISM precipitation during this time interval is similar to that of the Δ 1 4 C record and other ISM precipitation records during'the latest Holocene. This raises the hypothesis that multidecadal climate dynamics during the late Boiling-early Allerod may have been similar to those that operated during the last several millennia, even though the boundary conditions of these two time intervals were very different.

``Amount effect'' of water isotopes and quantitative analysis of post-condensation processes

Abstract: A numerical model is proposed that describes the interaction between raindrops and water vapour near the planetary boundary layer to explain the “amount effect”. This model relates the intensity to the isotopic composition of precipitation. The model resolves raindrop sizes, and explicitly includes: (1) the isotopic equilibration time of raindrops that is drop-size dependent; (2) raindrop transit times through the atmosphere; and (3) the evolution of the isotopic composition of vapour at various rain rates. At high rain rate, the precipitation through a layer is less equilibrated with the vapour because the isotopic equilibration time is long compared to the fast transit time, and there is a preponderance of large drops, which take longer to equilibrate. The δ18O of vapour in the lower atmosphere becomes lower as a result of the interaction with these raindrops of low δ18O, and the degree of depletion of 18O is higher when precipitation rates are high. The model reproduces time-series observations of isotopic composition of precipitation in Japan, and a vapour replenishment rate is inferred by either advection or evaporation of about 5% of the precipitation rate. The results could be the basis for a new parameterization of the isotopic equilibration for different precipitation types and rates in General Circulation Models (GCMs). When the model is applied to a GCM, this parameterization is important for places where precipitation occurs at cold temperatures (<15 °C). Copyright © 2007 John Wiley & Sons, Ltd.

Relative roles of biogenic emissions and Saharan dust as ice nuclei in the Amazon basin

Abstract: Some aerosol particles—known as ice nuclei—initiate ice formation in clouds, thereby influencing precipitation, cloud dynamics and incoming and outgoing solar radiation. Measurements of the concentration and elemental composition of ice nuclei in the Amazon basin indicate that local bioparticles and Saharan dust could explain the presence of almost all ice nuclei during the wet season.