scholarly journals Statistical Downscaling of Precipitation and Temperature Using Long Ashton Research Station Weather Generator in Zambia: A Case of Mount Makulu Agriculture Research Station

2017 ◽  
Vol 06 (03) ◽  
pp. 487-512 ◽  
Author(s):  
Charles Bwalya Chisanga ◽  
Elijah Phiri ◽  
Vernon R. N. Chinene
Keyword(s):  
Statistical Downscaling ◽  
Weather Generator ◽  
Research Station ◽  
Ashton Research Station ◽  
Precipitation And Temperature

Downscaling technique uncertainty in assessing hydrological impact of climate change in the Upper Beles River Basin, Ethiopia

2012 ◽  
Vol 44 (2) ◽  
pp. 377-398 ◽  
Author(s):  
Girma Yimer Ebrahim ◽  
Andreja Jonoski ◽  
Ann van Griensven ◽  
Giuliano Di Baldassarre
Keyword(s):  
River Basin ◽  
Daily Precipitation ◽  
Epistemic Uncertainty ◽  
Climate Impact ◽  
Percentage Change ◽  
Research Station ◽  
Model Ensembles ◽  
Ashton Research Station ◽  
Change In Mean ◽  
Precipitation And Temperature

We investigate the uncertainty associated with downscaling techniques in climate impact studies, using the Upper Beles River Basin (Upper Blue Nile) in Ethiopia as an example. The main aim of the study is to estimate the two sources of uncertainty in downscaling models: (1) epistemic uncertainty and (2) stochastic uncertainty due to inherent variability. The first aim was achieved by driving a Hydrologic Engineering Centre-Hydrological Modelling System (HEC-HMS) model with downscaled daily precipitation and temperature using three downscaling models: Statistical Downscaling Model (SDSM), the Long Ashton Research Station Weather Generator (LARS-WG) and an artificial neural network (ANN). The second objective was achieved by driving the hydrological model with individual downscaled daily precipitation and temperature ensemble members, generated by using the stochastic component of the SDSM. Results of the study showed that the downscaled precipitation and temperature time series are sensitive to the downscaling techniques. More specifically, the percentage change in mean annual flow ranges from 5% reduction to 18% increase. By analyzing the uncertainty of the SDSM model ensembles, it was found that the percentage change in mean annual flow ranges from 6% increase to 8% decrease. This study demonstrates the need for extreme caution in interpreting and using the output of a single downscaling model.

scholarly journals Evaluation of Flower, Fruit, and Juice Characteristics of a Multinational Collection of Cider Apple Cultivars Grown in the U.S. Pacific Northwest

2017 ◽  
Vol 27 (3) ◽  
pp. 431-439 ◽  
Author(s):  
Carol A. Miles ◽  
Jacqueline King ◽  
Travis Robert Alexander ◽  
Edward Scheenstra
Keyword(s):  
Pacific Northwest ◽  
Alcoholic Beverage ◽  
Fruit Size ◽  
Titratable Acidity ◽  
The United States ◽  
Research Station ◽  
Apple Cultivars ◽  
The Mean ◽  
Ashton Research Station ◽  
Strongly Consistent

Little information exists on the bloom and fruit characteristics of cider apple (Malus ×domestica) cultivars grown in the United States for the juice and alcoholic beverage markets. In this study, a total of 17 cider apple cultivars, including 4 American, 9 English, and 4 French, plus 1 Danish standard dessert apple cultivar (Red Gravenstein, Worthen strain) commonly used for cider, all grown in northwest Washington, were evaluated from 2000 to 2015 for commercially relevant traits. Trees were rated each year and the cultivars were categorized accordingly by relative bloom time, bloom habit, and productivity. The mean full bloom (FB) date of the 18 apple cultivars evaluated ranged from 25 Apr. to 25 May, with 6 cultivars categorized as early season bloomers, 9 as midseason, and 3 as late season. The mean bloom density (BD) rating (measured on a scale of 1–5) for all cultivars was (mean ± sd) 3.8 ± 0.6 (moderate bloom), with the bloom habit of 1 cultivar categorized as biennial, 11 as consistent, and 6 as strongly consistent. The mean productivity rating (measured on a scale of 1–5) for all cultivars was 2.9 ± 0.6 (light fruiting), with the productivity of 4 cultivars categorized as biennial, 10 as consistent, and 4 as strongly consistent. The mean fruit diameter of the 18 apple cultivars was 2.7 ± 0.4 inches (medium sized), with the fruit size of 2 cultivars categorized as small-fruited, 15 as medium-fruited, and 1 as large-fruited. For the 18 cultivars, the mean tannin and titratable acidity (TA) were 0.20% ± 0.14% and 0.54% ± 0.28%, respectively, and using the English cider apple classification system of juice type, 4 of the cultivars were classified as bittersweet, 1 as bittersharp, 3 as sweet, and 10 as sharp. Three of the cultivars had tannin content lower than what was historically recorded at the Long Ashton Research Station (LARS) in Bristol, England, for those same cultivars. The mean specific gravity (SG) of the 18 cultivars was 1.052 ± 0.007, the average predicted alcohol by volume (ABV) was 6.9% ± 0.9%, and the mean pH was 3.68 ± 0.39. Classification of three cultivars in northwest Washington, based on juice characteristics, differed from their historical classification in England, likely because of differences in climate and management. Only cultivars Golden Russet (sharp), Grimes Golden (sharp), and Yarlington Mill (sweet, but borderline bittersweet) were strongly consistent in productivity, but none produced high levels of tannin, whereas only cultivars Bramtot (bittersweet), Chisel Jersey (bittersweet), and Breakwell Seedling (bittersharp) were consistent in productivity and produced high levels of tannin.

A Versatile Weather Generator for Daily Precipitation and Temperature

2012 ◽  
Vol 55 (3) ◽  
pp. 895-906 ◽  
Author(s):  
J. Chen ◽  
F. P. Brissette ◽  
R. Leconte ◽  
A. Caron
Keyword(s):  
Daily Precipitation ◽  
Weather Generator ◽  
Precipitation And Temperature
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