Rainfall Intensity

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David A Randall - One of the best experts on this subject based on the ideXlab platform.

  • impacts of cloud superparameterization on projected daily Rainfall Intensity climate changes in multiple versions of the community earth system model
    Journal of Advances in Modeling Earth Systems, 2016
    Co-Authors: Gabriel J Kooperman, Michael S Pritchard, Mark Branson, Melissa Burt, David A Randall
    Abstract:

    Changes in the character of Rainfall are assessed using a holistic set of statistics based on Rainfall frequency and amount distributions in climate change experiments with three conventional and superparameterized versions of the Community Atmosphere Model (CAM and SPCAM). Previous work has shown that high-order statistics of present-day Rainfall Intensity are significantly improved with superparameterization, especially in regions of tropical convection. Globally the two modeling approaches project a similar future increase in mean Rainfall, especially across the Inter-Tropical Convergence Zone (ITCZ) and at high latitudes, but over land SPCAM predicts a smaller mean change than CAM. Changes in high-order statistics are similar at high-latitudes in the two models, but diverge at lower latitudes. In the tropics SPCAM projects a large intensification of moderate and extreme rain rates in regions of organized convection associated with the Madden Julian Oscillation, ITCZ, monsoons, and tropical waves. In contrast, this signal is missing in all versions of CAM, which are found to be prone to predicting increases in the amount but not Intensity of moderate rates. Predictions from SPCAM exhibit a scale-insensitive behavior with little dependence on horizontal resolution for extreme rates, while lower resolution (∼2˚) versions of CAM are not able to capture the response simulated with higher resolution (∼1˚). Moderate rain rates analyzed by the “amount mode” and “amount median” are found to be especially telling as a diagnostic for evaluating climate model performance and tracing future changes in Rainfall statistics to tropical wave modes in SPCAM. This article is protected by copyright. All rights reserved.

  • robust effects of cloud superparameterization on simulated daily Rainfall Intensity statistics across multiple versions of the community earth system model
    Journal of Advances in Modeling Earth Systems, 2016
    Co-Authors: Gabriel J Kooperman, Michael S Pritchard, Melissa A Burt, Mark Branson, David A Randall
    Abstract:

    PUBLICATIONS Journal of Advances in Modeling Earth Systems RESEARCH ARTICLE 10.1002/2015MS000574 Key Points: Superparameterization improves the Rainfall amount mode and extreme rates relative to TRMM 3B42 Mean Rainfall and dry day frequency biases do not improve much with superparameterization Conventional and superparameterized Rainfall Intensity statistics are similar poleward of 508 Robust effects of cloud superparameterization on simulated daily Rainfall Intensity statistics across multiple versions of the Community Earth System Model Gabriel J. Kooperman 1 , Michael S. Pritchard 1 , Melissa A. Burt 2 , Mark D. Branson 2 , and David A. Randall 2 Department of Earth System Science, University of California, Irvine, California, USA, 2 Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado, USA Abstract This study evaluates several important statistics of daily Rainfall based on frequency and Supporting Information: Supporting Information S1 Correspondence to: G. J. Kooperman, gkooperm@uci.edu Citation: Kooperman, G. J., M. S. Pritchard, M. A. Burt, M. D. Branson, and D. A. Randall (2016), Robust effects of cloud superparameterization on simulated daily Rainfall Intensity statistics across multiple versions of the Community Earth System Model, J. Adv. Model. Earth Syst., 8, 140–165, doi:10.1002/2015MS000574. Received 28 OCT 2015 Accepted 29 DEC 2015 Accepted article online 2 JAN 2016 Published online 1 FEB 2016 amount distributions as simulated by a global climate model whose precipitation does not depend on convective parameterization—Super-Parameterized Community Atmosphere Model (SPCAM). Three superparameterized and conventional versions of CAM, coupled within the Community Earth System Model (CESM1 and CCSM4), are compared against two modern Rainfall products (GPCP 1DD and TRMM 3B42) to discriminate robust effects of superparameterization that emerge across multiple versions. The geographic pattern of annual-mean Rainfall is mostly insensitive to superparameterization, with only slight improvements in the double-ITCZ bias. However, unfolding Intensity distributions reveal several improvements in the character of Rainfall simulated by SPCAM. The Rainfall rate that delivers the most accumulated rain (i.e., amount mode) is systematically too weak in all versions of CAM relative to TRMM 3B42 and does not improve with horizontal resolution. It is improved by superparameterization though, with higher modes in regions of tropical wave, Madden-Julian Oscillation, and monsoon activity. Superparameterization produces better representations of extreme rates compared to TRMM 3B42, with- out sensitivity to horizontal resolution seen in CAM. SPCAM produces more dry days over land and fewer over the ocean. Updates to CAM’s low cloud parameterizations have narrowed the frequency peak of light rain, converging toward SPCAM. Poleward of 508, where more Rainfall is produced by resolved-scale processes in CAM, few differences discriminate the Rainfall properties of the two models. These results are discussed in light of their implication for future Rainfall changes in response to climate forcing. 1. Introduction C 2016. The Authors. V This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. KOOPERMAN ET AL. Rainfall is an intrinsic characteristic of a region’s climate, by definition determining whether the region is a desert or rainforest [Peel et al., 2007]. As the Earth warms, global mean precipitation is expected to increase by 1–3% 8C 21 due to radiative constraints [Allen and Ingram, 2002; Pendergrass and Hartmann, 2014a; Ste- phens and Ellis, 2008], but regional changes are much less robust [Dai, 2006; Mahlstein et al., 2012; Stocker et al., 2013]. Regional Rainfall is driven over time by changes in circulation, moisture transport, and local evaporation [Trenberth et al., 2003]. These changes can depend on complex interactions between Rainfall, large-scale dynamics, and surface sensible and latent heat fluxes, especially over land where soil moisture coupling plays an important role [Seneviratne et al., 2010]. Interactions linked to the second-order statistics of Rainfall (e.g., frequency and Intensity) can determine whether rain is intercepted by the canopy, infiltrates the soil, or runs off the surface, thus influencing the soil moisture [Lawrence et al., 2011; Ramirex and Senar- ath, 2000]. In turn, the soil moisture effects local evaporation and sensible heat fluxes, which project onto large-scale dynamics and downstream moisture transport [Dirmeyer et al., 2009; Koster et al., 2004; Senevir- atne et al., 2010]. These second-order Rainfall characteristics are expected to change even more than the mean, up to 7% 8C 21 on global scales, and even larger on regional scales [O’Gorman, 2015; Trenberth et al., 2003]. For these reasons, and because Rainfall frequency and Intensity control the prevalence of devas- tating drought or flood conditions, it is critical they be realistically simulated in global climate models (GCMs). Rainfall Intensity STATISTICS IN SPCAM

Haitao Zhang - One of the best experts on this subject based on the ideXlab platform.

  • effect of slope Rainfall Intensity and mulch on erosion and infiltration under simulated rain on purple soil of south western sichuan province china
    Water, 2016
    Co-Authors: Muhammad Naeem Khan, Yuanbo Gong, Rattan Lal, Jiangkun Zheng, Meta Francis Justine, Muhammad Azhar, Mingxuan Che, Haitao Zhang
    Abstract:

    Purple soil is widely distributed in the hilly areas of the Sichuan basin, southwest China, and is highly susceptible to water erosion. The triggering of this process is related to slope, Rainfall Intensity and surface cover. Therefore, this study assesses the effects of different simulated Rainfall intensities with different slopes on hydrological and erosional processes in un-mulched and mulched purple soils. Results show that the sediment and water losses increased with an increase of Rainfall Intensity and slope steepness. Generally, the slope contribution (Sc) on water and sediment losses decreased with increasing Rainfall Intensity and slope steepness under both un-mulched and mulched soil. In un-mulched conditions, water losses were independent of slope steepness (Sc 50%, except during the increase in slope steepness from 15° to 25° under the highest Rainfall Intensity (120 mm·h−1). The effectiveness of mulch was more pronounced in reducing sediment losses (81%–100%) compared with water losses (14%–100%). The conservation effectiveness of mulch both decreased and increased with slope steepness for water and sediment losses, respectively, under higher Rainfall intensities. Water infiltration and recharge coefficient (RC) decreased with an increase of slope steepness, while with an increase in Rainfall Intensity, the water infiltration and RC were increased and decreased, respectively, in both un-mulched and mulched soil. On the other hand, mulched soil maintained a significantly (α = 0.05) higher infiltration capacity and RC compared to that of the un-mulched soil.

  • influence of microtopography ridge geometry and Rainfall Intensity on soil erosion induced by contouring failure
    Soil & Tillage Research, 2014
    Co-Authors: Qianjin Liu, Zhihua Shi, Haitao Zhang
    Abstract:

    Abstract Contour ridging is an effective soil conservation practice used throughout the world. Because of microtopographic relief on sloping land, rainwater concentrates in low areas along furrows where contouring failure can occur. To quantify the effects and interactions of factors that influence runoff and sediment yield induced by contouring failure, a total of 32 Rainfall simulation experiments were conducted, with two microtopography indices (row grade, RG, and field slope, FS), two ridge geometry indices (ridge height, H , and ridge width, W ), and two levels of Rainfall Intensity (RI) arranged in an L 16 (2 5 ) orthogonal array with two replications. The results showed that all of the factors considered except for row grade exerted significant influences on runoff and sediment yield ( p  = 0.01). Rainfall Intensity was the most important factor for runoff, with a contribution of 68.1%, followed by ridge height, field slope, and ridge width. Field slope and Rainfall interacted negatively, with a contribution of 5.4%, resulting in increased runoff with increasing field slope at lower Rainfall intensities, while the opposite effect was observed at higher Rainfall intensities. The negative interaction of ridge height and width and the positive interaction of field slope and ridge height also had significant effects on runoff. For sediment yield, the most important factor (21.4%) was ridge height, which had a negative effect. Rainfall Intensity had less effect on sediment yield than on runoff, while the row grade and its interaction with ridge width had greater influences. The optimal combinations of factors for control of runoff were determined to be RG 1 , FS 1 , H 2 , and W 2 for lower Rainfall Intensity and RG 1 , FS 2 , H 2 , and W 2 for higher Rainfall Intensity, and the optimal combinations of factors for sediment yield conservation were determined to be RG 1 , FS 1 , H 1 , and W 2 , where in all cases, the subscripts 1 and 2 denote lower and higher factor levels.

Ray B Bryant - One of the best experts on this subject based on the ideXlab platform.

  • role of Rainfall Intensity and hydrology in nutrient transport via surface runoff
    Journal of Environmental Quality, 2006
    Co-Authors: Peter J A Kleinman, A N Sharpley, M S Srinivasan, Curtis J Dell, John P Schmidt, Ray B Bryant
    Abstract:

    Loss of soil nutrients in runoff accelerates eutrophication of surface waters. This study evaluated P and N in surface runoff in relation to Rainfall Intensity and hydrology for two soils along a single hillslope. Experimentswereinitiatedon1-by2-mplotsatfoot-slope(6%)andmidslope (30%) positions within an alfalfa (Medicago sativa L.)–orchardgrass (Dactylis glomerata L.) field. Rain simulations (2.9 and 7.0 cm h 21 ) were conducted under wet (spring) and dry (late-summer) conditions. Elevated, antecedent soil moisture at the foot-slope during the spring resulted in less rain required to generate runoff and greater runoff volumes, compared with runoff from the well-drained mid-slope in spring and at both landscape positions in late summer. Phosphorus in runoff was primarily in dissolved reactive form (DRP averaged 71% of totalP),withDRPconcentrationsfromthetwosoilscorrespondingwith soiltestPlevels.Nitrogeninrunoffwasmainlynitrate(NO3–Naveraged 77%oftotalN).Sitehydrology,notchemistry,wasprimarilyresponsible for variations in mass N and P losses with landscape position. Larger runoff volumes from the foot-slope produced higher losses of total P (0.08 kg ha 21 ) and N (1.35 kg ha 21 ) than did runoff from the mid-slope (0.05 total P kg ha 21 ; 0.48 kg N ha 21 ), particularly under wet, spring

  • role of Rainfall Intensity and hydrology in nutrient transport via surface runoff
    Journal of Environmental Quality, 2006
    Co-Authors: Peter J A Kleinman, A N Sharpley, M S Srinivasan, Curtis J Dell, John P Schmidt, Ray B Bryant
    Abstract:

    Loss of soil nutrients in runoff accelerates eutrophication of surface waters. This study evaluated P and N in surface runoff in relation to Rainfall Intensity and hydrology for two soils along a single hillslope. Experiments were initiated on 1- by 2-m plots at foot-slope (6%) and mid-slope (30%) positions within an alfalfa (Medicago sativa L.)-orchardgrass (Dactylis glomerata L.) field. Rain simulations (2.9 and 7.0 cm h(-1)) were conducted under wet (spring) and dry (late-summer) conditions. Elevated, antecedent soil moisture at the foot-slope during the spring resulted in less rain required to generate runoff and greater runoff volumes, compared with runoff from the well-drained mid-slope in spring and at both landscape positions in late summer. Phosphorus in runoff was primarily in dissolved reactive form (DRP averaged 71% of total P), with DRP concentrations from the two soils corresponding with soil test P levels. Nitrogen in runoff was mainly nitrate (NO3-N averaged 77% of total N). Site hydrology, not chemistry, was primarily responsible for variations in mass N and P losses with landscape position. Larger runoff volumes from the foot-slope produced higher losses of total P (0.08 kg ha(-1)) and N (1.35 kg ha(-1)) than did runoff from the mid-slope (0.05 total P kg ha(-1); 0.48 kg N ha(-1)), particularly under wet, spring-time conditions. Nutrient losses were significantly greater under the high Intensity Rainfall due to larger runoff volumes. Results affirm the critical source area concept for both N and P: both nutrient availability and hydrology in combination control nutrient loss.

Dinghai Zhang - One of the best experts on this subject based on the ideXlab platform.

  • effects of Rainfall Intensity and intermittency on woody vegetation cover and deep soil moisture in dryland ecosystems
    Journal of Hydrology, 2016
    Co-Authors: Dinghai Zhang, Feng Zhang, Zhishan Zhang, Yongle Chen
    Abstract:

    Abstract Identifying the relationship between the stochastic daily Rainfall regime and the dynamics of plants and soil moisture is fundamental for the sustainable management of dryland ecosystems in a context of global climate change. An eco-hydrological model that couples the dynamics of woody vegetation cover and deep soil moisture (typically with a depth interval of 30–150 cm) was used to investigate the effect of stochastic Intensity and the intermittency of precipitation on soil moisture in this deep interval, which affects woody vegetation cover. Our results suggest that the precipitation Intensity and intermittency play an important role in the dynamics of wood vegetation cover and deep soil moisture. In arid and semiarid regions, as the annual precipitation increased, the rate of woody vegetation cover increased as a power-law function, and the deep soil moisture increased exponentially. For a given annual Rainfall, there were positive correlations between the Rainfall Intensity (or Rainfall intermittency) and both the woody vegetation cover and deep soil moisture. The positive correlations between wood vegetation cover and both Rainfall Intensity and intermittency may decrease with increases in the precipitation Intensity or precipitation intermittency. The positive correlations between deep soil moisture and both Rainfall Intensity and Rainfall intermittency increase as the precipitation Intensity or precipitation intermittency increases. Moreover, these positive correlations may increase with increases in the mean annual Rainfall. Our results emphasize the importance of daily precipitation variations in controlling the responses of woody vegetation cover and deep soil moisture to climate variations in arid and semiarid regions. Our model can aid the understanding of Rainfall processes and indicates that increases in Rainfall Intensity or Rainfall intermittency may lead to an increase in woody vegetation cover and deep soil moisture given an invariable annual Rainfall regime in dryland ecosystems.

A N Sharpley - One of the best experts on this subject based on the ideXlab platform.

  • Rainfall Intensity and phosphorus source effects on phosphorus transport in surface runoff from soil trays
    Science of The Total Environment, 2007
    Co-Authors: Francirose Shigaki, A N Sharpley, Luis Ignacio Prochnow
    Abstract:

    Phosphorus runoff from agricultural fields amended with mineral fertilizers and manures has been linked to freshwater eutrophication. A Rainfall simulation study was conducted to evaluate the effects of different Rainfall intensities and P sources differing in water soluble P (WSP) concentration on P transport in runoff from soil trays packed with a Berks loam and grassed with annual ryegrass (Lolium multiflorum Lam.). Triple superphosphate (TSP; 79% WSP), low-grade super single phosphate (LGSSP; 50% WSP), North Carolina rock phosphate (NCRP; 0.5% WSP) and swine manure (SM; 70% WSP), were broadcast (100 kg total P ha− 1) and Rainfall applied at 25, 50 and 75 mm h− 1 1, 7, 21, and 56 days after P source application. The concentration of dissolved reactive (DRP), particulate (PP), and total P (TP) was significantly (P < 0.01) greater in runoff with a Rainfall Intensity of 75 than 25 mm h− 1 for all P sources. Further, runoff DRP increased as P source WSP increased, with runoff from a 50 mm h− 1 rain 1 day after source application having a DRP concentration of 0.25 mg L− 1 for NCRP and 28.21 mg L− 1 for TSP. In contrast, the proportion of runoff TP as PP was greater with low (39% PP for NCRP) than high WSP sources (4% PP for TSP) averaged for all Rainfall intensities. The increased PP transport is attributed to the detachment and transport of undissolved P source particles during runoff. These results show that P source water solubility and Rainfall Intensity can influence P transport in runoff, which is important in evaluating the long-term risks of P source application on P transport in surface runoff.

  • role of Rainfall Intensity and hydrology in nutrient transport via surface runoff
    Journal of Environmental Quality, 2006
    Co-Authors: Peter J A Kleinman, A N Sharpley, M S Srinivasan, Curtis J Dell, John P Schmidt, Ray B Bryant
    Abstract:

    Loss of soil nutrients in runoff accelerates eutrophication of surface waters. This study evaluated P and N in surface runoff in relation to Rainfall Intensity and hydrology for two soils along a single hillslope. Experimentswereinitiatedon1-by2-mplotsatfoot-slope(6%)andmidslope (30%) positions within an alfalfa (Medicago sativa L.)–orchardgrass (Dactylis glomerata L.) field. Rain simulations (2.9 and 7.0 cm h 21 ) were conducted under wet (spring) and dry (late-summer) conditions. Elevated, antecedent soil moisture at the foot-slope during the spring resulted in less rain required to generate runoff and greater runoff volumes, compared with runoff from the well-drained mid-slope in spring and at both landscape positions in late summer. Phosphorus in runoff was primarily in dissolved reactive form (DRP averaged 71% of totalP),withDRPconcentrationsfromthetwosoilscorrespondingwith soiltestPlevels.Nitrogeninrunoffwasmainlynitrate(NO3–Naveraged 77%oftotalN).Sitehydrology,notchemistry,wasprimarilyresponsible for variations in mass N and P losses with landscape position. Larger runoff volumes from the foot-slope produced higher losses of total P (0.08 kg ha 21 ) and N (1.35 kg ha 21 ) than did runoff from the mid-slope (0.05 total P kg ha 21 ; 0.48 kg N ha 21 ), particularly under wet, spring

  • role of Rainfall Intensity and hydrology in nutrient transport via surface runoff
    Journal of Environmental Quality, 2006
    Co-Authors: Peter J A Kleinman, A N Sharpley, M S Srinivasan, Curtis J Dell, John P Schmidt, Ray B Bryant
    Abstract:

    Loss of soil nutrients in runoff accelerates eutrophication of surface waters. This study evaluated P and N in surface runoff in relation to Rainfall Intensity and hydrology for two soils along a single hillslope. Experiments were initiated on 1- by 2-m plots at foot-slope (6%) and mid-slope (30%) positions within an alfalfa (Medicago sativa L.)-orchardgrass (Dactylis glomerata L.) field. Rain simulations (2.9 and 7.0 cm h(-1)) were conducted under wet (spring) and dry (late-summer) conditions. Elevated, antecedent soil moisture at the foot-slope during the spring resulted in less rain required to generate runoff and greater runoff volumes, compared with runoff from the well-drained mid-slope in spring and at both landscape positions in late summer. Phosphorus in runoff was primarily in dissolved reactive form (DRP averaged 71% of total P), with DRP concentrations from the two soils corresponding with soil test P levels. Nitrogen in runoff was mainly nitrate (NO3-N averaged 77% of total N). Site hydrology, not chemistry, was primarily responsible for variations in mass N and P losses with landscape position. Larger runoff volumes from the foot-slope produced higher losses of total P (0.08 kg ha(-1)) and N (1.35 kg ha(-1)) than did runoff from the mid-slope (0.05 total P kg ha(-1); 0.48 kg N ha(-1)), particularly under wet, spring-time conditions. Nutrient losses were significantly greater under the high Intensity Rainfall due to larger runoff volumes. Results affirm the critical source area concept for both N and P: both nutrient availability and hydrology in combination control nutrient loss.