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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.


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Journal ArticleDOI
TL;DR: Improved estimates of surface reflectance from satellite data are used to show a close link between reductions in annual precipitation, El Niño southern oscillation events, and photosynthetic activity across tropical and subtropical Amazonia.
Abstract: We show that the vegetation canopy of the Amazon rainforest is highly sensitive to changes in precipitation patterns and that reduction in rainfall since 2000 has diminished vegetation greenness across large parts of Amazonia. Large-scale directional declines in vegetation greenness may indicate decreases in carbon uptake and substantial changes in the energy balance of the Amazon. We use improved estimates of surface reflectance from satellite data to show a close link between reductions in annual precipitation, El Nino southern oscillation events, and photosynthetic activity across tropical and subtropical Amazonia. We report that, since the year 2000, precipitation has declined across 69% of the tropical evergreen forest (5.4 million km2) and across 80% of the subtropical grasslands (3.3 million km2). These reductions, which coincided with a decline in terrestrial water storage, account for about 55% of a satellite-observed widespread decline in the normalized difference vegetation index (NDVI). During El Nino events, NDVI was reduced about 16.6% across an area of up to 1.6 million km2 compared with average conditions. Several global circulation models suggest that a rise in equatorial sea surface temperature and related displacement of the intertropical convergence zone could lead to considerable drying of tropical forests in the 21st century. Our results provide evidence that persistent drying could degrade Amazonian forest canopies, which would have cascading effects on global carbon and climate dynamics.

270 citations

Journal ArticleDOI
TL;DR: In this article, the authors examined large-scale changes in solid and total precipitation and satellite-derived snow cover over the North American continent and found a strong correlation exists between snow cover and temperature.
Abstract: Contemporary large-scale changes in solid and total precipitation and satellite-derived snow cover were examined over the North American continent. Annual snow cover extent over the last 19 years decreased up to 6×105 km2 relative to a 0.93°C (0.33°C) increase in North American (Northern Hemisphere) temperature. A strong correlation exists between snow cover and temperature where up to 78% of the variance in regional snow cover and snowfall is explained by the anomalies of monthly mean maximum temperature. Over the last two decades the decrease in snow cover during winter (December-March) has largely occurred through reduced frequency of snow cover in areas that typically have a high probability of snow on the ground with little change in the frequency of snow cover in other areas. Similar characteristics were observed during spring (April-May) in areas with high snow cover probability except for an expansion of the snow-free regions. Anomalies in these two seasons dominate the interannual variab...

269 citations

Journal ArticleDOI
TL;DR: In this article, the authors used multicentennial simulations of the modern (preindustrial) and mid-Holocene (6 kyr BP) climate, examining the internal variability and the forced response to orbital and greenhouse gas forcing.
Abstract: [1] Water isotopes provide a clear record of past climate variability but establishing their precise relationship to local or regional climate changes is the key to quantitative interpretations. We have incorporated water isotope tracers within the complete hydrological cycle of Goddard Institute for Space Studies coupled ocean-atmosphere model (ModelE) in order to assess these relationships. Using multicentennial simulations of the modern (preindustrial) and mid-Holocene (6 kyr BP) climate, we examine the internal variability and the forced response to orbital and greenhouse gas forcing. Modelled isotopic anomalies clearly reflect climatic changes and, particularly in the tropics, are more regionally coherent than the precipitation anomalies. Matches to observations at the mid-Holocene and over the instrumental period are good. We calculate water isotope-climate relationships for many patterns of intrinsic and for forced variability relevant to the Holocene, and we show that in general, calibrations depend on the nature of the climate change. Specifically, we examine relationships between isotopes in precipitation and local temperatures and precipitation amounts in the principal ice coring regions (Greenland, Antarctica, and the tropical Andes) and the seawater isotope-salinity gradients in the ocean. We suggest that isotope-based climate reconstructions based on spatial patterns and nonlocal calibrations will be more robust than interpretations based on local relationships.

269 citations

Journal ArticleDOI
TL;DR: In this paper, the authors examined the problems and challenges of forecasting lake effect snows, and several techniques designed to improve operational forecasts of lake effect snow are described in detail, along with representative case studies.
Abstract: This article is the final installment of a four-part series that examines the challenge of forecasting winter weather throughout the eastern United States. This paper examines the problems and challenges of forecasting lake effect snows. The climatology of lake-induced snowfall is reviewed, and an overview of the characteristics and evolution of these mesoscale precipitation bands is presented. The atmospheric conditions associated with five different types of lake snow bands are discussed. The abilities of remote sensors to resolve, and dynamical models to simulate, these mesoscale events are also explored. Finally, several techniques designed to improve operational forecasts of lake effect snow are described in detail, along with representative case studies.

269 citations

Journal ArticleDOI
TL;DR: It is revealed that, in addition to temperature and SWC, rain plays a role in determining the total amount of carbon released from soils, even in a maritime climate.
Abstract: Soil respiration (SR) was monitored periodically throughout 2001 in a Scots pine (Pinus sylvestris L.) stand located in the Belgian Campine region. As expected for a temperate maritime forest, temperature was the dominant control over SR during most of the year. However, during late spring and summer, when soil water content (SWC) was limiting, SR was insensitive to temperature (Q(10) = 1.24). We observed that during prolonged rain-free periods, when SWC was less than 15% (v/v), SR decreased dramatically (up to 50%) and SWC took over control of SR. During such drought periods, however, rain events sometimes stimulated SR and restored temperature control over SR, even though SWC in the mineral soil was low. We hypothesize that restoration of temperature control occurred only when rain events adequately rewetted the uppermost soil layers, where most of the respiratory activity occurred. To quantify the rewetting capacity of rain events, an index (I(w)) was designed that incorporated rainfall intensity, time elapsed since the last rain event, and atmospheric vapor pressure deficit (a proxy for evaporative water losses). To simulate SR fluxes, a model was developed that included the effects of soil temperature and, under drought and non-rewetting conditions (I(w) and SWC < threshold), an SWC response function. The model explained 95% of the temporal variability in SR observed during summer, whereas the temperature function alone explained only 73% of this variability. Our results revealed that, in addition to temperature and SWC, rain plays a role in determining the total amount of carbon released from soils, even in a maritime climate.

268 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20237,839
202214,365
20212,302
20201,964
20191,942
20181,773