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.

Five hundred years of gridded high-resolution precipitation reconstructions over Europe and the connection to large-scale circulation

Abstract: We present seasonal precipitation reconstructions for European land areas (30°W to 40°E/30–71°N; given on a 0.5°×0.5° resolved grid) covering the period 1500–1900 together with gridded reanalysis from 1901 to 2000 (Mitchell and Jones 2005). Principal component regression techniques were applied to develop this dataset. A large variety of long instrumental precipitation series, precipitation indices based on documentary evidence and natural proxies (tree-ring chronologies, ice cores, corals and a speleothem) that are sensitive to precipitation signals were used as predictors. Transfer functions were derived over the 1901–1983 calibration period and applied to 1500–1900 in order to reconstruct the large-scale precipitation fields over Europe. The performance (quality estimation based on unresolved variance within the calibration period) of the reconstructions varies over centuries, seasons and space. Highest reconstructive skill was found for winter over central Europe and the Iberian Peninsula. Precipitation variability over the last half millennium reveals both large interannual and decadal fluctuations. Applying running correlations, we found major non-stationarities in the relation between large-scale circulation and regional precipitation. For several periods during the last 500 years, we identified key atmospheric modes for southern Spain/northern Morocco and central Europe as representations of two precipitation regimes. Using scaled composite analysis, we show that precipitation extremes over central Europe and southern Spain are linked to distinct pressure patterns. Due to its high spatial and temporal resolution, this dataset allows detailed studies of regional precipitation variability for all seasons, impact studies on different time and space scales, comparisons with high-resolution climate models as well as analysis of connections with regional temperature reconstructions.

Inter-decadal variation of the summer precipitation in China and its association with decreasing Asian summer monsoon Part II: Possible causes

Abstract: The present article is the second part of a study on the inter-decadal variability of the summer precipitation in East China, which mainly addresses the possible cause of this change. Firstly, an updated analysis of the long-term variations of snow cover, snow days and snow depth in the preceding winter and spring over the Tibetan Plateau (TP) was done by using station and satellite data. The abrupt increase in the winter and spring snow over the TP since around 1977 has been well documented. At that time, the inter-decadal variation of the atmospheric heating over the TP in spring and summer had been estimated. It has been revealed that the atmospheric heating fields in subsequent spring and summer over the TP assumed a significant weakening after the late 1970s. This weakening is closely related to the significantly reduced surface sensible heat flux into the atmosphere and subsequent cooling over the TP and its surrounding atmosphere. The latter was produced by the increase of surface albedo and soil hydrological effect of melting snow under the condition of abrupt increase in the preceding winter and spring snow over the TP. On the other hand, three phases of significant inter-decadal warming of the sea surface temperature (SST) in the tropical central and eastern Pacific, which occurred in the mid-1960s, the late 1970s and the early 1990s, respectively, have been found. The above inter-decadal variability of heating fields over the land area in the Asian region and neighbouring oceanic region of the West Pacific has consistently reduced the land–sea thermal contrast in summer in the Asian monsoon region based on the estimate of atmospheric heating fields. This cause is likely to lead to weakening of the Asian summer monsoon. In such case, the northward moisture transport in East Asia is greatly weakened and cannot reach North China, thus causing the condition of less precipitation or droughts. In contrast, the Yangtze River basin and South China receive a large amount of moisture supply and have strong upward motion, creating favourable conditions for frequent occurrence of heavy rainfall. In the process of the southward shift of the high-precipitation zone, two abrupt or rapid regime shifts observed in the late 1970s and the early 1990s were possibly in response to the increase in the winter and spring snow over the TP, and two major rapid warming events of the SST in the tropical central and eastern Pacific in the late 1970s and the early 1990s. Correlative analysis has further confirmed that high TP snow and oceanic forcing factors have a positive correlation with the subsequent summer precipitation in the Yangtze River basin and most of South China, and a negative correlation with the summer precipitation in North China. This correlative relationship implies that if the TP has excessive (deficient) snow in the preceding winter and spring and the tropical central and eastern Pacific anomalously warms up (cools down), North China will have decreasing (increasing) summer precipitation, whereas the Yangtze River basin and South China will have increasing (decreasing) summer precipitation. Copyright © 2009 Royal Meteorological Society

Mean, interannual variability and trends in a regional climate change experiment over Europe. II: climate change scenarios (2071–2100)

Abstract: We present an analysis of climate change over Europe as simulated by a regional climate model (RCM) nested within time-slice atmospheric general circulation model (AGCM) experiments. Changes in mean and interannual variability are discussed for the 30-year period of 2071–2100 with respect to the present day period of 1961–1990 under forcing from the A2 and B2 IPCC emission scenarios. In both scenarios, the European region undergoes substantial warming in all seasons, in the range of 1–5.5°C, with the warming being 1–2°C lower in the B2 than in the A2 scenario. The spatial patterns of warming are similar in the two scenarios, with a maximum over eastern Europe in winter and over western and southern Europe in summer. The precipitation changes in the two scenarios also show similar spatial patterns. In winter, precipitation increases over most of Europe (except for the southern Mediterranean regions) due to increased storm activity and higher atmospheric water vapor loadings. In summer, a decrease in precipitation is found over most of western and southern Europe in response to a blocking-like anticyclonic circulation over the northeastern Atlantic which deflects summer storms northward. The precipitation changes in the intermediate seasons (spring and fall) are less pronounced than in winter and summer. Overall, the intensity of daily precipitation events predominantly increases, often also in regions where the mean precipitation decreases. Conversely the number of wet days decreases (leading to longer dry periods) except in the winter over western and central Europe. Cloudiness, snow cover and soil water content show predominant decreases, in many cases also in regions where precipitation increases. Interannual variability of both temperature and precipitation increases substantially in the summer and shows only small changes in the other seasons. A number of statistically significant regional trends are found throughout the scenario simulations, especially for temperature and for the A2 scenario. The results from the forcing AGCM simulations and the nested RCM simulations are generally consistent with each other at the broad scale. However, significant differences in the simulated surface climate changes are found between the two models in the summer, when local physics processes are more important. In addition, substantial fine scale detail in the RCM-produced change signal is found in response to local topographical and coastline features.

Five hundred years of gridded high-resolution precipitation reconstructions over Europe and the connection to large-scale

Abstract: We present seasonal precipitation reconstruc- tions for European land areas (30� Wt o 40� E/30-71� N; given on a 0.5�· 0.5� resolved grid) covering the period 1500-1900 together with gridded reanalysis from 1901 to 2000 (Mitchell and Jones 2005). Principal component regression techniques were applied to develop this dataset. A large variety of long instrumental precipitation series, precipitation indices based on documentary evidence and natural proxies (tree-ring chronologies, ice cores, corals and a speleothem) that are sensitive to precipitation sig- nals were used as predictors. Transfer functions were de- rived over the 1901-1983 calibration period and applied to 1500-1900 in order to reconstruct the large-scale pre- cipitation fields over Europe. The performance (quality estimation based on unresolved variance within the cali- bration period) of the reconstructions varies over centu- ries, seasons and space. Highest reconstructive skill was found for winter over central Europe and the Iberian Peninsula. Precipitation variability over the last half millennium reveals both large interannual and decadal fluctuations. Applying running correlations, we found major non-stationarities in the relation between large- scale circulation and regional precipitation. For several periods during the last 500 years, we identified key atmospheric modes for southern Spain/northern Mor- occo and central Europe as representations of two pre- cipitation regimes. Using scaled composite analysis, we show that precipitation extremes over central Europe and southern Spain are linked to distinct pressure patterns. Due to its high spatial and temporal resolution, this dataset allows detailed studies of regional precipitation variability for all seasons, impact studies on different time and space scales, comparisons with high-resolution cli- mate models as well as analysis of connections with re- gional temperature reconstructions.

Cloud cover limits net CO2 uptake and growth of a rainforest tree during tropical rainy seasons

Abstract: Recent global-scale analyses indicate that climate variability affects net carbon storage but regard temperature and precipitation to be the main contributors. Seasonal and interannual variation in light availability may also limit CO(2) uptake. As an experimental test of light limitation by cloud cover during tropical rainy seasons and by the unusually heavy cloud cover associated with La Nina, we installed high-intensity lamps above the forest canopy to augment light for Luehea seemannii, a tropical canopy tree species, during cloudy periods of 1999-2000. Light augmentation only partially compensated for the reduction in photosynthetic photon flux density caused by clouds. Nonetheless, leaves acclimated to the augmented irradiance, and photosynthesis, vegetative growth, and reproduction increased significantly. Light, rather than water, temperature, or leaf nitrogen, was the primary factor limiting CO(2) uptake during the rainy season.