HEAVY RAINFALL PATTERN OVER NORTH WESTERN PARTS IN DRY FARMING REGION OF INDIA

Abstract In this paper, a modified probability-matching technique is developed for ensemble-based quantitative precipitation forecasts (QPFs) associated with landfalling typhoons over Taiwan. The main features of this technique include a resampling of the ensemble realizations, a rainfall pattern adjustment, and a bias correction. Using this technique, a synthetic ensemble is created for the purpose of rainfall prediction from a large-size (32 members), low-resolution (36 km) ensemble and a small-size (8 members), high-resolution (4 km) ensemble. The rainfall pattern is adjusted based on the precipitation distribution of the 36- and 4-km ensembles. A bias-correction scheme is then applied to remove the known systematic bias from the resampled 4-km ensemble realizations as part of the probability-matching procedure. The modified probability-matching scheme is shown to substantially reduce or eliminate the intrinsic model rainfall bias and to provide better QPF guidance. The encouraging results suggest that this modified probability-matching technique is a useful tool for the QPF of the topography-enhanced typhoon heavy rainfall over Taiwan using ensemble forecasts at dual resolutions.

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On the occurrence of a less usual rainfall pattern in northeastern Brazil during the 2019 El Niño

10.21203/rs.3.rs-227770/v1 ◽

2021 ◽

Author(s):

Victor Azevedo Godoi ◽

Felipe M. de Andrade

Keyword(s):

El Niño ◽

Heavy Rainfall ◽

El Nino ◽

Lower Troposphere ◽

Longwave Radiation ◽

South Pacific ◽

South Atlantic ◽

Northeastern Brazil ◽

Rainfall Pattern ◽

Average Rainfall

Abstract El Niño is generally associated with below-average rainfall in northeastern Brazil (NEB). In 2019, however, the opposite rainfall pattern was observed during an El Niño episode. Here, we explore the mechanisms that overwhelmed typical El Niño-related conditions and resulted in above-average rainfall in NEB. We focus on the austral autumn, when El Niño is most related to rainfall anomalies in the region. The analysis of rainfall data from weather stations and the Global Precipitation Climatology Project, upper- and lower-level circulation reanalysis data, sea surface temperature data, outgoing longwave radiation data, and modelled data allowed us to identify that the autumn 2019 heavy rainfall in NEB was likely associated with three combined factors; these are: (1) the weak intensity of the 2019 El Niño; (2) local and remote diabatic heating anomalies, especially over the western South Pacific and tropical South Atlantic, which resulted in anticyclonic and cyclonic circulations in the upper and lower troposphere, respectively, over the tropical South Atlantic; and (3) sub-seasonal atmospheric convection anomalies over the western South Pacific, which reinforced the low-frequency convection signal over that region. This latter factor suggests the influence of the Madden–Julian Oscillation on rainfall in NEB during the first ten days of March. We discuss these mechanisms in detail and provide evidence for their associations with the anomalously heavy rainfall in NEB. Our results may assist in the planning of several crucial activities, such as water resources management and agriculture.

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Identifying the Changes in Rainfall Pattern and Heavy Rainfall Events During 1871–2010 over Cherrapunji

High-Impact Weather Events over the SAARC Region ◽

10.1007/978-3-319-10217-7_23 ◽

2014 ◽

pp. 335-345

Author(s):

Pulak Guhathakurta ◽

Preetha Menon ◽

N. B. Nipane

Keyword(s):

Heavy Rainfall ◽

Rainfall Pattern ◽

Rainfall Events ◽

Heavy Rainfall Events

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Evaluation of reanalysis and global meteorological products in Beas river basin of North-Western Himalaya

ENVIRONMENTAL SYSTEMS RESEARCH ◽

10.1186/s40068-020-00186-1 ◽

2020 ◽

Vol 9 (1) ◽

Author(s):

Tanmoyee Bhattacharya ◽

Deepak Khare ◽

Manohar Arora

Keyword(s):

River Basin ◽

Meteorological Data ◽

Western Himalaya ◽

Temperature Data ◽

Rainfall Pattern ◽

Climate Data ◽

Orographic Rainfall ◽

Hydrology Model ◽

North Western ◽

Good Agreement

Abstract It is a great challenge to obtain reliable gridded meteorological data in some data-scarce and complex territories like the Himalaya region. Less dense observed raingauge data are unable to represent rainfall variability in the Beas river basin of North-Western Himalaya. In this study four reanalyses (MERRA, ERA-Interim, JRA-55 and CFSR) and one global meteorological forcing data WFDEI have been used to evaluate the potential of the products to represent orographic rainfall pattern of Beas river basin using hydrology model. The modeled climate data have compared with observed climate data for a long term basis. A comparison of various rainfall and temperature products helps to determine uniformity and disparity between various estimates. Results show that all temperature data have a good agreement with gridded observed data. ERA-Interim temperature data is better in terms of bias, RMSE (Root Mean Square Error), and correlation compared to other data. On the other hand, MERRA, ERA-Interim and JRA-55 models have overestimated rainfall values, but CFSR and WFDEI models have underestimated rainfall values to the measured values. Variable Infiltration Capacity (VIC), a macroscale distributed hydrology model has been successfully applied to indirectly estimate the performance of five gridded meteorological data to represent Beas river basin rainfall pattern. The simulation result of the VIC hydrology model forced by these data reveals that the discharge of ERA-Interim has a good agreement with observed streamflow. In contrast there is an overestimated streamflow observed for MERRA reanalysis estimate. JRA-55, WFDEI, and CFSR data underestimate the streamflow. The reanalysis products are also poor in capturing the seasonal hydrograph pattern. The ERA-Interim product better represents orographic rainfall for the Beas river basin. The reason may be the ERA-Interim uses a four-dimensional variational analysis model during assimilation. The major drawback of MERRA is the non-inclusion of observed precipitation data during assimilation and modeling error. The poor performance of JRA-55, CFSR and WFDEI is due to the gauge rainfall data assimilation error. This research finding will help for broader research on hydrology and meteorology of the Himalayan region.

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Rainfall pattern greatly affects water use by Mongolian Scots pine on a sandy soil, in a semi-arid climate

10.5194/bg-2017-69 ◽

2017 ◽

Author(s):

Hongzhong Dang ◽

Lizhen Zhang ◽

Wenbin Yang ◽

Jinchao Feng ◽

Hui Han ◽

...

Keyword(s):

Soil Moisture ◽

Water Use ◽

Sandy Soil ◽

Heavy Rainfall ◽

Rainfall Pattern ◽

Severe Drought ◽

Sap Flux ◽

Sap Flux Density ◽

Tree Water Use ◽

Moderate Drought

Abstract. We report new information on tree water use by Mongolian Scots pine (Pinus sylvestris var. mongolica) growing on a sandy soil, in a region characterised by an erratic rainfall pattern. Measurements were made over three successive years of contrasting annual rainfall – a wet year (2013), a dry year (2014), and a second dry year (2015). The result was the development of worsening levels of drought year by year. Over the three years, sap flux density (Js) was measured at individual tree level in up to 25 trees. The sap flux density values were up-scaled to estimate tree water use at plot level (Ts). Our measurements follow forest plot response to increasing levels of drought which developed over a three-year period as soil moisture conditions gradually worsened from wet, to moderate-drought, to severe-drought, to extreme-drought, in response to the dynamics of a variable rainfall pattern. Values of Ts did not exceed 3.03 mm day−1 (2013), 1.75 mm day−1 (2014) and 1.59 mm day−1 (2015) during the three growing seasons. Total annual stand transpiration over the same three years declined progressively from 290 mm (2013), to 182 mm (2014) and to 175 mm (2015). Satisfactory power-function relationships (R2 = 0.64) between daily Ts and the product of ET0 and the relative extractable soil water (REW) were found. This study helps elucidate the interplay between the effects of the atmosphere and soil moisture on tree water use. Tree water use responded to drought, with daily Ts values decreasing by 5–46 % in response to moderate drought, by 48–62 % in response to severe drought and by 65 % in response to extreme drought. Upon release of moderate drought by heavy rainfall in 2013, daily Ts recovered completely. However, under the severe and extreme droughts in the subsequent dry years, recovery of Ts following heavy rainfall was incomplete (57–58 %). Our results highlight the negative effects of water stress on the growth of mature forest trees, in a sandy soil, in a climate characterised by large intra- and inter-annual variances in rainfall. When the erratic rainfall and sandy soil were also coupled with a declining groundwater table, the result was tree water use fluctuated widely over quite short time scales (months or weeks). Overall, our findings account for the observed premature degradation of these MP plantations in terms of an eco-hydrological perspective.

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The impact of onion cultivation at irrigation on the productivity of spring barley in the system of dry farming in the North-Western Pre-Caspian

The Agrarian Scientific Journal ◽

10.28983/asj.y2019i6pp19-26 ◽

2019 ◽

pp. 19-26

Author(s):

Natalya Ivanovna Matveeva ◽

Yury Nikolaevich Petrov ◽

Elena Vladimirovna Kalmykova ◽

Olga Vladimirovna Kalmykova ◽

Viktor Bisengalievich Narushev

Keyword(s):

Climatic Factors ◽

Spring Barley ◽

Experimental Studies ◽

Vegetation Period ◽

Barley Grain ◽

Soil Conditions ◽

The North ◽

Dry Farming ◽

The Impact ◽

North Western

They are given technological schemes for the rational development of the agricultural lands of the periodic irrigation of the North-Western Pre-Caspian. Experimental studies were carried out to study the water and physical properties of periodically irrigated light chestnut soils in the system of dry farming in the North-Western Pre-Caspian. Observations, accounting and economic calculations were carried out in accordance with generally accepted methods. During all the years of research, barley yields on periodically irrigated plots, regardless of the meteorological conditions of the growing season, were higher than the corresponding indicators on rainfed plots by 1,5...3,0 times. The average yield of barley grain was 2.43 t / ha - after onion, 0.91 t / ha –after autumn ploughing. Crops after onions with drip irrigation were distinguished by high profitability - from 57.5 to 173.4% (on average – 129.5%), whereas, crops on dry-farming land were unprofitable from eight years in three because of the dry conditions of the vegetation period. The developed technology of periodic irrigation in conjunction with climatic factors and soil conditions of the North-Western Pre-Caspian, as well as the technical means of its implementation, makes it possible to significantly reduce the degradation processes of the irrigated soils of the region and reduce the cost of producing spring grain crops.

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