scholarly journals Accelerating assimilation development for new observing systems using EFSO

2018 ◽  
Vol 25 (1) ◽  
pp. 129-143 ◽  
Author(s):  
Guo-Yuan Lien ◽  
Daisuke Hotta ◽  
Eugenia Kalnay ◽  
Takemasa Miyoshi ◽  
Tse-Chun Chen
Keyword(s):  
Selection Criteria ◽  
Ensemble Forecast ◽  
Data Selection ◽  
Development Work ◽  
Observation Data ◽  
Precipitation Data ◽  
Trial And Error ◽  
Satellite Precipitation ◽  
Selection Strategies ◽  
Observing Systems

Abstract. To successfully assimilate data from a new observing system, it is necessary to develop appropriate data selection strategies, assimilating only the generally useful data. This development work is usually done by trial and error using observing system experiments (OSEs), which are very time and resource consuming. This study proposes a new, efficient methodology to accelerate the development using ensemble forecast sensitivity to observations (EFSO). First, non-cycled assimilation of the new observation data is conducted to compute EFSO diagnostics for each observation within a large sample. Second, the average EFSO conditionally sampled in terms of various factors is computed. Third, potential data selection criteria are designed based on the non-cycled EFSO statistics, and tested in cycled OSEs to verify the actual assimilation impact. The usefulness of this method is demonstrated with the assimilation of satellite precipitation data. It is shown that the EFSO-based method can efficiently suggest data selection criteria that significantly improve the assimilation results.

scholarly journals Accelerating assimilation development for new observing systems using EFSO

2017 ◽  
Author(s):  
Guo-Yuan Lien ◽  
Daisuke Hotta ◽  
Eugenia Kalnay ◽  
Takemasa Miyoshi ◽  
Tse-Chun Chen
Keyword(s):  
Ensemble Forecast ◽  
Data Selection ◽  
Development Work ◽  
Observation Data ◽  
Precipitation Data ◽  
Trial And Error ◽  
Selection Rules ◽  
Satellite Precipitation ◽  
Selection Strategies ◽  
Observing Systems

Abstract. To successfully assimilate data from a new observing system, it is necessary to develop appropriate data selection strategies, assimilating only the generally useful data. This development work is usually done by trial-and-error using observing system experiments, which are very time- and resource-consuming. This study proposes a new, efficient methodology to accelerate the development using the Ensemble Forecast Sensitivity to Observations (EFSO). First, non-cycled assimilation of the new observation data is conducted to compute EFSO diagnostics for each observation. Second, the average EFSO conditionally sampled in terms of various factors is computed. Third, potential data selection rules are designed based on the EFSO results, and tested in cycled OSEs to verify the actual assimilation impact. The usefulness of this method is demonstrated with the assimilation of satellite precipitation data. It is shown that the EFSO based method can efficiently suggest data selection rules that significantly improve the assimilation results.

scholarly journals Application of TRMM Precipitation Data to Evaluate Drought and Its Effects on Water Resources Instability

2019 ◽  
Vol 9 (24) ◽  
pp. 5377
Author(s):  
Ata Amini ◽  
Abdolnabi Abdeh Kolahchi ◽  
Nadhir Al-Ansari ◽  
Mehdi Karami Moghadam ◽  
Thamer Mohammad
Keyword(s):  
Water Resources ◽  
Standardized Precipitation Index ◽  
Remote Sensing Data ◽  
Tropical Rainfall Measuring Mission ◽  
Monthly Precipitation ◽  
Precipitation Data ◽  
Discharge Data ◽  
Satellite Precipitation ◽  
Discharge Rates ◽  
Trmm Precipitation

The present research was carried out to study drought and its effects upon water resources using remote sensing data. To this end, the tropical rainfall measuring mission (TRMM) satellite precipitation, the synoptic stations, and fountain discharge data were employed. For monitoring of drought in the study area, in Kermanshah province, Iran, the monthly precipitation data of the synoptic stations along with TRMM satellite precipitation datasets were collected and processed in the geographic information system (GIS) environment. Statistical indicators were applied to evaluate the accuracy of TRMM precipitation against the meteorological stations’ data. Standardized precipitation index, SPI, and normalized fountain discharge were used in the monitoring of drought conditions, and fountains discharge, respectively. The fountains were selected so that in addition to enjoying the most discharge rates, they spread along the study area. The evaluation of precipitation data showed that the TRMM precipitation data were of high accuracy. Studies in temporal scale are indicative of the strike of drought in this region to the effect that for most months of the year, frequency and duration in dry periods are much more than in wet periods. As for seasonal scales, apart from winter, the frequency and duration of drought in spring and autumn have been longer than in wet years. Moreover, the duration of these periods was different. A comparison between the results of changes in fountain discharges and drought index in the region has verified that the drought has caused a remarkable decline in the fountain discharges.

N-N-N∗ model calculations for experimental η-mesic 3He searches

2019 ◽  
Vol 28 (08) ◽  
pp. 1950066 ◽  
Author(s):  
N. G. Kelkar ◽  
H. Kamada ◽  
M. Skurzok
Keyword(s):  
Experimental Data ◽  
Data Analysis ◽  
Momentum Distribution ◽  
Selection Criteria ◽  
Data Selection ◽  
Model Calculations ◽  
Faddeev Equations ◽  
Essential Ingredient ◽  
Momentum Distributions ◽  
Three Body

The possibility for the existence of the exotic [Formula: see text] states is explored with the objective of calculating the [Formula: see text] momentum distribution inside such nuclei. Even though the latter is an essential ingredient for the analysis of the experimental data on the [Formula: see text], [Formula: see text] and [Formula: see text] reactions aimed at finding an [Formula: see text]-mesic 3He, the data analysis is usually performed by approximating the [Formula: see text] momentum distribution by that of a nucleon. Here, we present calculations performed by solving the three-body Faddeev equations to obtain the momentum distribution of the [Formula: see text] inside possible ([Formula: see text])[Formula: see text], ([Formula: see text])[Formula: see text] and ([Formula: see text])[Formula: see text]-[Formula: see text] states. The [Formula: see text] momentum distributions are found to be much narrower than those of the nucleons and influence the data selection criteria.

scholarly journals Validation of TRMM 3B42V7 Rainfall Product under Complex Topographic and Climatic Conditions over Hexi Region in the Northwest Arid Region of China

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1006 ◽  
Author(s):  
Xiuna Wang ◽  
Yongjian Ding ◽  
Chuancheng Zhao ◽  
Jian Wang
Keyword(s):  
Bias Correction ◽  
Arid Region ◽  
Rain Gauge ◽  
Climatic Conditions ◽  
Monthly Precipitation ◽  
Observation Data ◽  
Precipitation Data ◽  
Rain Gauges ◽  
Hexi Region ◽  
Precipitation Events

Continuous and accurate spatiotemporal precipitation data plays an important role in regional climate and hydrology research, particularly in the arid inland regions where rain gauges are sparse and unevenly distributed. The main objective of this study is to evaluate and bias-correct the Tropical Rainfall Measuring Mission (TRMM) 3B42V7 rainfall product under complex topographic and climatic conditions over the Hexi region in the northwest arid region of China with the reference of rain gauge observation data during 2009–2015. A series of statistical indicators were adopted to quantitatively evaluate the error of 3B42V7 and its ability in detecting precipitation events. Overall, the 3B42V7 overestimates the precipitation with Bias of 11.16%, and its performance generally becomes better with the increasing of time scale. The agreements between the rain gauge data and 3B42V7 are very low in cold season, and moderate in warm season. The 3B42V7 shows better correlation with rain gauges located in the southern mountainous and central oasis areas than in the northern extreme arid regions, and is more likely to underestimate the precipitation in high-altitude mountainous areas and overestimate the precipitation in low-elevation regions. The distribution of the error on the daily scale is more related to the elevation and rainfall than in monthly and annual scale. The 3B42V7 significantly overestimates the precipitation events, and the overestimation mainly focuses on tiny amounts of rainfall (0–1 mm/d), which is also the range of false alarm concentration. Bias correction for 3B42V7 was carried out based on the deviation of the average monthly precipitation data during 2009–2015. The bias-corrected 3B42V7 was significantly improved compared with the original product. Results suggest that regional assessment and bias correction of 3B42V7 rainfall product are of vital importance and will provide substantive reference for regional hydrological studies.

scholarly journals Legitimacy of uncertain policy work: Exploring values in local economic development projects

2020 ◽  
Vol 35 (5) ◽  
pp. 440-459
Author(s):  
Albin Olausson
Keyword(s):  
Economic Development ◽  
Organization Theory ◽  
Local Governments ◽  
Local Economic Development ◽  
Local Development ◽  
Development Work ◽  
Development Projects ◽  
Observation Data ◽  
To Come ◽  
Development Agents

This article takes the standpoint that, due to high levels of uncertainty, local economic development work suffers from both input- and output-based legitimacy. Nevertheless, local governments are active development agents and try to come up with economic development initiatives. In order to better understand the legitimate basis for uncertain economic development work, this article offers an unconventional analysis of economic development projects. Drawing on scholars of organization theory, legitimacy is defined as congruence in values between the studied projects and the stakeholders in the surrounding environment. The article examines what kinds of values pervade local governments’ economic development projects. The empirical material is based on thick interview and observation data derived from a study of eight local development projects in Sweden. The results show that values of professionalization and deliberation pervade the analysed projects. Taking the two sets of values together, the results indicate that local government administration seeks to legitimize its economic development work as being based on professional directed processes of public deliberation. Both these sets of values challenge the local representative democratic system of government as the prime source of the legitimacy of local governments’ interventions.

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