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.

Effect of precipitation sampling error on simulated hydrological fluxes and states: Anticipating the Global Precipitation Measurement satellites

Abstract: [1] Precipitation is the single most important determinant of the fluxes and states of the land surface hydrological system and the most important atmospheric input to hydrological models. Satellite-based precipitation estimates, such as those anticipated from the Global Precipitation Measurement (GPM) satellites, hold great promise for application in hydrologic simulation and prediction, especially in parts of the world where surface observation networks are sparse. However, the usefulness of these precipitation products for hydrological applications will depend on their error characteristics. Of particular interest in satellite-derived precipitation estimates is the sampling error, that is, the error in accumulated precipitation due to periodic sampling of the precipitation rate. To assess the effect of this error on simulated hydrological fluxes and states, synthetic error fields were imposed on an observation-based 1/2° latitude/longitude gridded precipitation data set. In turn, the generated precipitation fields were used as input to a macroscale hydrology model (MHM). Our results show that (1) streamflow errors were large for small drainage areas but decreased rapidly for drainage areas larger than about 50,000 km2. Much of the streamflow error is associated with fast (near-surface) runoff response. (2) Streamflow estimates were biased upward due to sampling errors, with the bias increasing with sampling interval and with drainage area. Evapotranspiration was biased downward in a compensating amount. (3) Spatial correlation of precipitation errors reduced the rate at which errors decreased with drainage area for all variables investigated, but the differences between the correlated and uncorrelated error cases were smaller for streamflow and evapotranspiration than for precipitation.

Effect of Catchment‐Scale Subsurface Mixing on Stream Isotopic Response

Abstract: A 3.8-ha watershed on the west coast of New Zealand was instrumented with suction lysimeters and automatic water samplers to determine the relationship between subsurface isotopic and chemical concentrations to those of rainfall and resulting streamflow. A t test showed that ±2‰ represented a significant difference between successive sample deuterium values. Eleven rainfall episodes were subdivided into two categories: (1) two events where stream isotopic composition did not deflect >2‰ from prestorm values, and (2) four events which demonstrated new water flushing. Detailed analysis of one 47-mm rainfall (9.8-mm runoff) event showed that old water dominated stream water exiting the watershed by 90% using a standard two-component hydrograph separation for deuterium (corroborated by Cl and electrical conductivity). Three-component hydrograph separation indicated that 12–16% was in the form of soil water, with <5% as on-channel precipitation and 80% groundwater. Analysis of over 1000 water samples revealed systematic trends in soil water and groundwater isotopic composition both in a downslope and downprofile direction. Between-storm suction lysimeter deuterium data showed a systematic dampened response to temporally variable rainfall deuterium concentrations. Multivariate cluster analysis revealed three distinct soil water/groundwater groupings, with respect to soil depth and geographic position within the watershed. Within-storm suction lysimeter sampling preserved similar groupings, indicating that the subsurface reservoir is poorly mixed on short time scales. Understanding subsurface mixing response to rainfall should greatly improve models of episodic stream response and partitioning of storm flow into waters of different age.

Trends in extreme rainfall events of Bangladesh

Abstract: A study of the variability of the extreme rainfall events in Bangladesh during the time period 1958–2007 has been carried out in this paper. Quality-controlled homogeneous daily precipitation records of nine stations distributed over Bangladesh are used for the study. A total of 15 annual and seasonal indices of rainfall are examined. Variability of annual and seasonal rainfall trends is also assessed. The Mann–Kendall statistic and Sen's Slope model are used to reveal the trends and estimate the magnitude of change, respectively. A significant increase of annual and pre-monsoon rainfall in Bangladesh is observed. In general, an increasing trend in heavy precipitation days and decreasing trends in consecutive dry days are observed. Significant change in most of the extreme rainfall indices are observed in Northwest Bangladesh.

The Severe Thunderstorm Electrification and Precipitation Study

Abstract: During May–July 2000, the Severe Thunderstorm Electrification and Precipitation Study (STEPS) occurred in the High Plains, near the Colorado–Kansas border. STEPS aimed to achieve a better understanding of the interactions between kinematics, precipitation, and electrification in severe thunderstorms. Specific scientific objectives included 1) understanding the apparent major differences in precipitation output from super-cells that have led to them being classified as low precipitation (LP), classic or medium precipitation, and high precipitation; 2) understanding lightning formation and behavior in storms, and how lightning differs among storm types, particularly to better understand the mechanisms by which storms produce predominantly positive cloud-to-ground (CG) lightning; and 3) verifying and improving microphysical interpretations from polarimetric radar. The project involved the use of a multiple-Doppler polarimetric radar network, as well as a time-of-arrival very high frequency (VHF) lig...