scholarly journals Evaluation of Three Gridded Precipitation Products to Quantify Water Inputs over Complex Mountainous Terrain of Western China

2021 ◽  
Vol 13 (19) ◽  
pp. 3795
Author(s):  
Liping Zhang ◽  
Ping Lan ◽  
Guanghua Qin ◽  
Carlos R. Mello ◽  
Elizabeth W. Boyer ◽  
...  
Keyword(s):  
Complex Terrain ◽  
Extreme Rainfall ◽  
Rain Gauge ◽  
Western China ◽  
Key Factors ◽  
Detection Capability ◽  
Short Term ◽  
Regional Topography ◽  
Stable Performance

This study evaluates the capacity of three gridded precipitation products (MSWEP V2.2, TRMM-3B42 V7, and GPM-IMERG V6) to detect precipitation in the Min Jiang watershed, a data-scarce and mountainous region in western China. A set of statistical and contingency indices is calculated for the precipitation products and compared with rain gauge observations at 23 ground stations from July 2000 to May 2016. Consistency between gridded and ground precipitation datasets is examined at different temporal (i.e., daily, monthly, seasonally, and annually) and spatial (i.e., site level, sub-regional level, and watershed level) resolutions. We identify possible reasons for discrepancies among precipitation datasets. Our results indicate that: (1) the MSWEP product is best suited for the study of long-term mesoscale rainfall, rather than short-term light or extreme rainfall; (2) the IMERG product represents stable performance for the simulation of rainfall spatial variability and detection capability; and (3) Composition of the datasets, climatic systems, and regional topography are key factors influencing the consistency between gridded and ground precipitation datasets. Therefore, we suggest using MSWEP V2.2 and GPM-IMERG V6 as potential precipitation data sources for hydrometeorological studies over the Min Jiang watershed. The findings of this study inform future hydrometeorological and climate applications in data-scarce regions with complex terrain.

scholarly journals Radar and Rain Gauge Analysis of the Extreme Rainfall during Hurricane Danny’s (1997) Landfall

2007 ◽  
Vol 135 (5) ◽  
pp. 1869-1888 ◽  
Author(s):  
Jeffrey M. Medlin ◽  
Sytske K. Kimball ◽  
Keith G. Blackwell
Keyword(s):  
Inner Core ◽  
Temporal Distribution ◽  
Extreme Rainfall ◽  
Rain Gauge ◽  
Rainfall Amount ◽  
Mobile Bay ◽  
Maximum Rainfall ◽  
Torrential Rainfall ◽  
First Time

Abstract As a minimal hurricane, Danny moved over Mobile Bay around 0900 UTC 19 July 1997 and became stationary by midmorning, while situated within a synoptic col. Danny then evolved into an asymmetric storm with an intensely convective rainband that produced torrential rainfall through 1200 UTC 20 July 1997. Danny’s center remained <100 km from the National Weather Service (NWS) Weather Surveillance Radar-1988 Doppler (WSR-88D) in Mobile, Alabama, for over 48 h, allowing long-term surveillance of the storm’s inner core. This event marked the first time the tropical Z–R relationship was employed on an operational WSR-88D system during tropical cyclone landfall. A radar-estimated maximum rainfall accumulation of 1097 mm (43.2 in.) was analyzed over southwestern Mobile Bay. A NWS cooperative rain gauge located on Dauphin Island, Alabama, measured 896 mm (35.28 in.). An adjacent standard rain gauge measured the highest rainfall amount of 932 mm (36.71 in.). This paper investigates the spatial and temporal distribution and potential magnitude of Danny’s torrential rainfall episode over coastal Alabama. It is shown that both gauges and radar seriously underestimated event rainfall. An estimate is given for what could have been the true event rainfall amount. In the case of the radar, the WSR-88D Algorithm Testing and Display System is used to obtain a better estimate of rainfall using higher dBZ caps than the operational 50 dBZ. In the case of the tipping-bucket rain gauge, wind and mechanical error estimates were applied in order to quantify rainfall underestimation.

scholarly journals Statistical Characteristic of Heavy Rainfall Associated with Typhoons near Taiwan Based on High-Density Automatic Rain Gauge Data

2016 ◽  
Vol 97 (8) ◽  
pp. 1363-1375 ◽  
Author(s):  
Chun-Chieh Wu ◽  
Tzu-Hsiung Yen ◽  
Yi-Hsuan Huang ◽  
Cheng-Ku Yu ◽  
Shin-Gan Chen
Keyword(s):  
Heavy Rainfall ◽  
Extreme Rainfall ◽  
Rain Gauge ◽  
Statistical Characteristics ◽  
Rain Gauge Data ◽  
Mountainous Regions ◽  
Rain Gauges ◽  
Weather Stations ◽  
Central Weather Bureau

Abstract This study utilizes data compiled over 21 years (1993–2013) from the Central Weather Bureau of Taiwan to investigate the statistical characteristics of typhoon-induced rainfall for 53 typhoons that have impacted Taiwan. In this work the data are grouped into two datasets: one includes 21 selected conventional weather stations (referred to as Con-ST), and the other contains all the available rain gauges (250–500 gauges, mostly automatic ones; referred to as All-ST). The primary aim of this study is to understand the potential impacts of the different gauge distributions between All-ST and Con-ST on the statistical characteristics of typhoon-induced rainfall. The analyses indicate that although the average rainfall amount calculated with Con-ST is statistically similar to that with All-ST, the former cannot identify the precipitation extremes and rainfall distribution appropriately, especially in mountainous areas. Because very few conventional stations are located over the mountainous regions, the cumulative frequency obtained solely from Con-ST is not representative. As compared to the results from All-ST, the extreme rainfall assessed from Con-ST is, on average, underestimated by 23%–44% for typhoons approaching different portions of Taiwan. The uneven distribution of Con-ST, with only three stations located in the mountains higher than 1000 m, is likely to cause significant biases in the interpretation of rainfall patterns. This study illustrates the importance of the increase in the number of available stations in assessing the long-term rainfall characteristic of typhoon-associated heavy rainfall in Taiwan.

scholarly journals Dynamical Insights into Extreme Short-Term Precipitation Associated with Supercells and Mesovortices

2018 ◽  
Vol 75 (9) ◽  
pp. 2983-3009 ◽  
Author(s):  
Erik R. Nielsen ◽  
Russ S. Schumacher
Keyword(s):  
Flash Flood ◽  
Extreme Rainfall ◽  
Heavy Precipitation ◽  
Rain Gauge ◽  
Gradient Force ◽  
Pressure Gradient Force ◽  
Short Term ◽  
Low Level ◽  
Convective Systems ◽  
Vertical Accelerations

Abstract In some prominent extreme precipitation and flash flood events, radar and rain gauge observations have suggested that the heaviest short-term rainfall accumulations (up to 177 mm h−1) were associated with supercells or mesovortices embedded within larger convective systems. In this research, we aim to identify the influence that rotation has on the storm-scale processes associated with heavy precipitation. Numerical model simulations conducted herein were inspired by a rainfall event that occurred in central Texas in October 2015 where the most extreme rainfall accumulations were collocated with meso-β-scale vortices. Five total simulations were performed to test the sensitivity of precipitation processes to rotation. A control simulation, based on a wind profile from the aforementioned event, was compared with two experiments with successively weaker low-level shear. With greater environmental low-level shear, more precipitation fell, in both a point-maximum and an area-averaged sense. Intense, rotationally induced low-level vertical accelerations associated with the dynamic nonlinear perturbation vertical pressure gradient force were found to enhance the low- to midlevel updraft strength and total vertical mass flux and allowed access to otherwise inhibited sources of moisture and CAPE in the higher-shear simulations. The dynamical accelerations, which increased with the intensity of the low-level shear, dominated over buoyant accelerations in the low levels and were responsible for inducing more intense low-level updrafts that were sustained despite a stable boundary layer.

scholarly journals Sustainability of the Funded Ratio and Asset Allocation Choice of State Public Pension Plans

2019 ◽  
Vol 9 (1) ◽  
pp. 366
Author(s):  
Amod Choudhary ◽  
Nikolaos Papanikolaou
Keyword(s):  
Asset Allocation ◽  
The United States ◽  
Pension Plans ◽  
Public Pension ◽  
Key Factors ◽  
Short Term ◽  
Investment Returns ◽  
Current Member ◽  
Public Pension Plans

The paper examines State Public Pension Plans in the United States and the sustainability of their funded ratios. The authors apply a panel logit with random effects regression model of asset allocation choice and average returns during fiscal years 2001 to 2015. There are three key factors which adequately fund State Public Pension Plans: (i) current member contributions, (ii) members’ employer contributions, and (iii) investment returns on those contributions. Returns on those contributions depend heavily on allocation choice of those funds in traditional and alternative investments. Alternatives are generally assumed to provide higher average returns with higher risk. This paper shows that in the long-term, investment in traditional assets such as bonds, equities and short-term cash have a higher likelihood of funding State Public Pension Plan’s payment obligations to beneficiaries.

scholarly journals Acute exposure to nicotine vapor causes short-term increases in impulsive choice in rats

2019 ◽  
Author(s):  
R.J. Flores ◽  
F.Z. Alshbool ◽  
P. Giner ◽  
L.E. O’Dell ◽  
I.A. Mendez
Keyword(s):  
Delay Discounting ◽  
Male Rats ◽  
Enzyme Linked Immunosorbent Assay ◽  
Impulsive Choice ◽  
Short Term ◽  
Serum Cotinine ◽  
Choice Preference ◽  
Long Term Changes ◽  
Stable Performance

AbstractBackgroundPrevious studies have shown that exposure to nicotine smoke increases impulsivity. Surprisingly, research investigating the effects of electronic cigarette nicotine vapor exposure on impulsivity has not been conducted. Therefore, the present study examined the effects of nicotine vapor exposure on impulsive choice.MethodsTwenty-four adult male rats were trained in the delay discounting task to choose between small immediate food rewards or larger food rewards with delayed deliveries. After 24 days of training in the delay discounting task, rats were passively exposed to vapor containing either 0, 12, or 24 mg/mL of nicotine for 10 days. To monitor exposure to nicotine, serum cotinine levels were assessed on exposure days 1, 5, and 10 using enzyme-linked immunosorbent assay (ELISA). Following vapor exposure, rats were retrained in the delay discounting task until stable performance was achieved, and the effects of nicotine vapor exposure on choice preference were assessed.ResultsRats that were exposed to 12 and 24 mg/mL nicotine vapor displayed higher serum cotinine levels, relative to those exposed to 0 mg/mL nicotine vapor. There were no differences in impulsive choice between any of the vapor groups when tested 15-21 days after exposure. However, increases in impulsive choice were observed when testing immediately following exposure to 24 mg/mL nicotine vapor, relative to immediately following exposure to 0 mg/mL nicotine vapor.ConclusionsFindings suggest that while exposure to nicotine vapor may not cause long-term changes in decision making, it can cause short-term increases in impulsive choice, an effect that can have negative social and health consequences.

Improving Satellite-Based Rainfall Accumulation Estimates Using Spaceborne Surface Soil Moisture Retrievals

2009 ◽  
Vol 10 (1) ◽  
pp. 199-212 ◽  
Author(s):  
Wade T. Crow ◽  
George J. Huffman ◽  
Rajat Bindlish ◽  
Thomas J. Jackson
Keyword(s):  
Soil Moisture ◽  
Surface Soil ◽  
Rain Gauge ◽  
Surface Soil Moisture ◽  
Complementary Information ◽  
Short Term ◽  
Rain Gauge Data ◽  
Gauge Data ◽  
Cover Density

Abstract Over land, remotely sensed surface soil moisture and rainfall accumulation retrievals contain complementary information that can be exploited for the mutual benefit of both product types. Here, a Kalman filtering–based tool is developed that utilizes a time series of spaceborne surface soil moisture retrievals to enhance short-term (2- to 10-day) satellite-based rainfall accumulation products. Using ground rain gauge data as a validation source, and a soil moisture product derived from the Advanced Microwave Scanning Radiometer aboard the NASA Aqua satellite, the approach is evaluated over the contiguous United States. Results demonstrate that, for areas of low to moderate vegetation cover density, the procedure is capable of improving short-term rainfall accumulation estimates extracted from a variety of satellite-based rainfall products. The approach is especially effective for correcting rainfall accumulation estimates derived without the aid of ground-based rain gauge observations. Special emphasis is placed on demonstrating that the approach can be applied in continental areas lacking ground-based observations and/or long-term satellite data records.

scholarly journals Evaluation of a forest parameterization to improve boundary layer flow simulations over complex terrain

2021 ◽  
Author(s):  
Julian Quimbayo-Duarte ◽  
Johannes Wagner ◽  
Norman Wildmann ◽  
Thomas Gerz ◽  
Juerg Schmidli
Keyword(s):  
Boundary Layer ◽  
High Resolution ◽  
Wind Speed ◽  
Complex Terrain ◽  
Grid Spacing ◽  
Short Term ◽  
Valley Wind ◽  
Layer Flow ◽  
Horizontal Grid

Abstract. We evaluate the influence of a forest parametrization on the simulation of the boundary layer flow over moderate complex terrain in the context of the Perdigão 2017 field campaign. The numerical simulations are performed using the Weather research and forecasting model using its large eddy simulation mode (WRF-LES). The short-term high resolution (40 m horizontal grid spacing) and long-term (200 m horizontal grid spacing) WRF-LES are evaluated for an integration time of 12 hours and 1.5 months, respectively, with and without forest parameterization. The short-term simulations focus on low-level jet events over the valley, while the long-term simulations cover the whole intensive observation period (IOP) of the field campaign. The results are validated using lidar and meteorological tower observations. The mean diurnal cycle during the IOP shows a significant improvement of the along-valley wind speed and the wind direction when using the forest parametrization. However, the drag imposed by the parametrization results in an underestimation of the cross-valley wind speed, which can be attributed to a poor representation of the land surface characteristics. The evaluation of the high-resolution WRF-LES shows a positive influence of the forest parametrization on the simulated winds in the first 500 m above the surface.

scholarly journals Dynamical Mechanisms Supporting Extreme Rainfall Accumulations in the Houston “Tax Day” 2016 Flood

2019 ◽  
Vol 148 (1) ◽  
pp. 83-109 ◽  
Author(s):  
Erik R. Nielsen ◽  
Russ S. Schumacher
Keyword(s):  
Rain Rate ◽  
Extreme Rainfall ◽  
Rain Gauge ◽  
Intense Rainfall ◽  
Convective Rainfall ◽  
Short Term ◽  
Low Level ◽  
Hourly Rainfall ◽  
Scale Characteristics ◽  
Extreme Rain

Abstract This research examines the environmental and storm-scale characteristics of the extreme rainfall and flooding in the Houston, Texas, area on 18 April 2016, known as the “Tax Day” flood. Radar and local mesonet rain gauge observations were used to identify the locations and structures of extreme rain-rate-producing cells, with special attention given to rotating updrafts. To supplement this observation-based analysis, a WRF-ARW simulation of the Tax Day storm in 2016 was examined for the influence of any attendant rotation on both the dynamics and microphysics of the cells producing the most intense short-term (i.e., subhourly to hourly) rainfall accumulations. Results show that the most intense rainfall accumulations in the model analysis, as in the observational analysis, are associated with rotating convective elements. A lowering of the updraft base, enhancement of the low-level vertical velocities, and increased low-level rainwater production is seen in rotating updrafts, compared to those without rotation. These differences are also maintained despite increased hydrometeor loading. The results agree with the findings of previous idealized model simulations that show dynamical accelerations associated with meso-γ-scale rotation can enhance convective rainfall rates.

scholarly journals How Farmers Make Investment Decisions: Evidence from a Farmer Survey in China

2019 ◽  
Vol 12 (1) ◽  
pp. 247 ◽  
Author(s):  
Shuangjin Wang ◽  
Yuan Tian ◽  
Xiaowei Liu ◽  
Maggie Foley
Keyword(s):  
Investment Decisions ◽  
Physical Capital ◽  
Multinomial Logit Model ◽  
Grain Production ◽  
Key Factors ◽  
Short Term ◽  
Factors Affecting ◽  
Output Elasticity ◽  
The Cost

Based on the grain production data hand collected in Mid-East China, a multinomial Logit model was employed to analyze factors that are critical to farmers’ investment decisions in food production. Reasonable explanations are provided to help understand differences between expected farmers’ investments in grain production and the actual results. It was found that the cost of machinery and the number of farmers is key factors affecting farmers’ willingness to adjust investment. Further research shows that most of the farmers who had the willingness to adjust investment did not implement the adjustments in the short-term. From the micro-adaptability expectation perspective, the time that it takes to adjust the planting area could explain farmers’ investment adjustment intention and the behavior. From the macro-investment perspective, short-term output elasticity of physical capital is less than long-term output elasticity. The differences between farmers’ willingness to invest and the actual results are therefore generated. These findings suggest that it is necessary to strengthen the application of big data technology in agriculture in order to improve the platforms’ efficiency in data releasing and reaching out to farmers to provide more accurate advice regarding investment adjustment.

scholarly journals Restoring lions Panthera leo to northern KwaZulu-Natal, South Africa: short-term biological and technical success but equivocal long-term conservation

Oryx ◽  
2007 ◽  
Vol 41 (2) ◽  
pp. 196-204 ◽  
Author(s):  
L.T.B. Hunter ◽  
K. Pretorius ◽  
L. C. Carlisle ◽  
M. Rickelton ◽  
C. Walker ◽  
...  
Keyword(s):  
South Africa ◽  
Home Ranges ◽  
Large Carnivores ◽  
Key Factors ◽  
Short Term ◽  
Kwazulu Natal ◽  
Release Area ◽  
Methodological Considerations

AbstractThe success of efforts to re-establish mammalian carnivores within their former range is dependent on three key factors: methodological considerations, the biological requirements of the target species, and the involvement of local human communities for whom large carnivores pose a threat. We consider the role of these factors in the first 13 years of an effort to re-establish wild lions in northern KwaZulu-Natal Province, South Africa. We employed soft-release methods to mitigate the characteristic problems associated with restoration of large carnivores. A pre-release captivity period facilitated acclimatization of reintroduced lions and promoted long-term bonding of unfamiliar individuals into cohesive groups. All individuals remained in the release area and established enduring, stable home ranges. Reintroduced lions successfully reproduced and raised 78% of their cubs to independence. Human activity was the cause of all post-release mortality. Despite rapid population growth and the re-establishment of the species at Phinda Private Game Reserve, the population is small and isolated with little prospect for re-colonizing additional areas where the species has been extirpated, or for connecting with other isolated lion populations in the region. Accordingly, although we essentially overcame the short-term technical and biological challenges facing lion reintroduction, the long-term value of the Phinda population for addressing the conservation issues facing the species remains equivocal.

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