Assimilation of GPS radio occultation data at DWD

Abstract. We describe the status of the assimilation of bending angles from GPS radio occultations in the 3D-Var for DWD's operational global forecast model GME ("Global Model for Europe"). Experiments show that the assimilation of GPSRO data leads to a significant reduction of biases in the analyses of temperature, humidity and wind in the upper troposphere and the stratosphere, as well as a better r. m. s. fit in the comparison to radiosondes. The impact on forecasts is most prominent in the data sparse Southern Hemisphere, but is also quite notable in the Northern Hemisphere extra-tropics, where we also see a slightly positive impact on surface pressure. The positive results found in the impact experiments lead to the implementation of the assimilation of GPS radio occultations from GRACE-A, FORMOSAT-3/COSMIC and GRAS/MetOp-A into the operational suite on 3 August 2010. We also show some initial results from assimilation experiments using radio occultation data from the German research satellite TerraSAR-X.

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Assimilation of GPS radio occultation data at DWD

Atmospheric Measurement Techniques ◽

10.5194/amt-4-1105-2011 ◽

2011 ◽

Vol 4 (6) ◽

pp. 1105-1113 ◽

Cited By ~ 18

Author(s):

H. Anlauf ◽

D. Pingel ◽

A. Rhodin

Keyword(s):

Radio Occultation ◽

Forecast Model ◽

German Research ◽

The Status ◽

Occultation Data ◽

The Impact ◽

Impact Experiments ◽

Positive Results ◽

Initial Results ◽

Radio Occultation Data

Abstract. We describe the status of the assimilation of bending angles from GPS radio occultations in the 3D-Var for DWD's operational global forecast model GME ("Global Model for Europe"). Experiments show that the assimilation of GPSRO data leads to a significant reduction of biases in the analyses of temperature, humidity and wind in the upper troposphere and the stratosphere, as well as a better r. m. s. fit in the comparison to radiosondes. The impact on forecasts is most prominent in the data sparse Southern Hemisphere, but is also quite notable in the Northern Hemisphere extra-tropics. The positive results found in the impact experiments lead to the implementation of the assimilation of GPS radio occultations from GRACE-A, FORMOSAT-3/COSMIC and GRAS/MetOp-A into the operational suite on 3 August 2010. We also show some initial results from assimilation experiments using radio occultation data from the German research satellite TerraSAR-X.

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Estimation of the Added Value of the Absolute Calibration of GPS Radio Occultation Data for Numerical Weather Prediction

Monthly Weather Review ◽

10.1175/mwr-d-14-00153.1 ◽

2015 ◽

Vol 143 (4) ◽

pp. 1259-1274 ◽

Cited By ~ 7

Author(s):

Josep M. Aparicio ◽

Stéphane Laroche

Keyword(s):

Bias Correction ◽

Radio Occultation ◽

Weather Prediction ◽

Added Value ◽

Atmospheric Measurements ◽

Gps Radio Occultation ◽

Correction Scheme ◽

Occultation Data ◽

The Impact ◽

Radio Occultation Data

Abstract An analysis of the impact of GPS radio occultation observations on Environment Canada’s global deterministic weather prediction system is presented. Radio occultation data, as any other source of weather observations, have a direct impact on the analyses. Since they are assimilated assuming that they are well calibrated, they also impact the bias correction scheme employed for other data, such as satellite radiances. The authors estimate the relative impact of occultation data obtained from, first, their assimilation as atmospheric measurements and, second, their influence on the bias correction for radiance data. This assessment is performed using several implementations of the thermodynamic relationships involved, and also allowing or blocking this influence to the radiance bias correction scheme. The current implementation of occultation operators at Environment Canada is presented, collecting upgrades that have been detailed elsewhere, such as the equation of state of air and the expression of refractivity. The performance of the system with and without assimilation of occultations is reviewed under conditions representative of current operations. Several denial runs are prepared, withdrawing only the occultation data from the assimilation, but keeping their influence on the radiance bias correction, or assimilating occultations but denying their impact on the bias correction procedure, and a complete denial. It is shown that the impact of occultations on the analysis is significant through both paths—assimilation and radiance bias correction—albeit the first is larger. The authors conclude that the traceability link of the ensemble of occultations has an added value, beyond the value of each datum as an atmospheric measurement.

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Impact of Infrared, Microwave, and Radio Occultation Satellite Observations on Operational Numerical Weather Prediction

Monthly Weather Review ◽

10.1175/mwr-d-14-00101.1 ◽

2014 ◽

Vol 142 (11) ◽

pp. 4164-4186 ◽

Cited By ~ 14

Author(s):

L. Cucurull ◽

R. A. Anthes

Keyword(s):

Radio Occultation ◽

Positive Impact ◽

Weather Prediction ◽

Lower Troposphere ◽

Correlation Coefficients ◽

Forecast Model ◽

Satellite Observation ◽

Satellite Observations ◽

Satellite Systems ◽

The Impact

Abstract A comparison of the impact of infrared (IR), microwave (MW), and radio occultation (RO) observations on NCEP’s operational global forecast model over the month of March 2013 is presented. Analyses and forecasts with only IR, MW, and RO observations are compared with analyses and forecasts with no satellite data and with each other. Overall, the patterns of the impact of the different satellite systems are similar, with the MW observations producing the largest impact on the analyses and RO producing the smallest. Without RO observations, satellite radiances are over– or under–bias corrected and RO acts as an anchor observation, reducing the forecast biases globally. Positive correlation coefficients of temperature impacts are generally found between the different satellite observation analyses, indicating that the three satellite systems are affecting the global temperatures in a similar way. However, the correlation in the lower troposphere among all three systems is surprisingly small. Correlations for the moisture field tend to be small in the lower troposphere between the different satellite analyses. The impact of the satellite observations on the 500-hPa geopotential height forecasts is much different in the Northern and Southern Hemispheres. In the Northern Hemisphere, all the satellite observations together make a small positive impact compared to the base (no satellite) forecasts. The IR and MW, but not the RO, make a small positive impact when assimilated alone. The situation is considerably different in the Southern Hemisphere, where all the satellite observations together make a much larger positive impact, and all three observation types (IR, MW, and RO) make similar and significant impacts.

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The impact of spherical symmetry assumption on radio occultation data inversion in the ionosphere: An assessment study

Advances in Space Research ◽

10.1016/j.asr.2013.10.025 ◽

2014 ◽

Vol 53 (4) ◽

pp. 599-608 ◽

Cited By ~ 8

Author(s):

M.M. Shaikh ◽

R. Notarpietro ◽

B. Nava

Keyword(s):

Spherical Symmetry ◽

Radio Occultation ◽

Data Inversion ◽

Assessment Study ◽

Symmetry Assumption ◽

Occultation Data ◽

The Impact ◽

Radio Occultation Data

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Ionospheric correction of GPS radio occultation data in the troposphere

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-8-7781-2015 ◽

2015 ◽

Vol 8 (7) ◽

pp. 7781-7803

Author(s):

Z. Zeng ◽

S. Sokolovskiy ◽

W. Schreiner ◽

D. Hunt ◽

J. Lin ◽

...

Keyword(s):

Radio Occultation ◽

Neutral Atmosphere ◽

Ionospheric Correction ◽

Bending Angle ◽

Gps Radio Occultation ◽

Occultation Data ◽

L1 And L2 ◽

The Impact ◽

Radio Occultation Data ◽

Bending Angles

Abstract. For inversions of the GPS radio occultation (RO) data in the neutral atmosphere, this study investigates an optimal transition height for replacing the standard ionospheric correction by the linear combination of the L1 and L2 bending angles with the correction of the L1 bending angle by the L1-L2 bending angle extrapolated from above. The optimal transition height depends on the RO mission (i.e., the receiver and firmware) and is different between rising and setting occultations and between L2P and L2C GPS signals. This height is within the range approximately 10–20 km. One fixed transition height, which can be used for the processing of currently available GPS RO data, can be set to 20 km. Analysis of the L1CA and the L2C bending angles in the presence of a sharp top of the boundary layer reveals differences that can be explained by shifts in the impact parameter. The ionosphere-induced vertical shifts of the bending angle profiles require further investigation.

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Strategic Role of Zakat in Multidimensional Quality of Life in Sijunjung, Indonesia

The Journal of Muamalat and Islamic Finance Research ◽

10.33102/jmifr.v15i1.101 ◽

2018 ◽

Vol 15 (1) ◽

pp. 55-72

Author(s):

Herlin Hamimi ◽

Abdul Ghafar Ismail ◽

Muhammad Hasbi Zaenal

Keyword(s):

Quality Of Life ◽

Positive Impact ◽

Wealth Distribution ◽

Absolute Poverty ◽

Before And After ◽

The Status ◽

Being There ◽

The Impact

Zakat is one of the five pillars of Islam which has a function of faith, social and economic functions. Muslims who can pay zakat are required to give at least 2.5 per cent of their wealth. The problem of poverty prevalent in disadvantaged regions because of the difficulty of access to information and communication led to a gap that is so high in wealth and resources. The instrument of zakat provides a paradigm in the achievement of equitable wealth distribution and healthy circulation. Zakat potentially offers a better life and improves the quality of human being. There is a human quality improvement not only in economic terms but also in spiritual terms such as improving religiousity. This study aims to examine the role of zakat to alleviate humanitarian issues in disadvantaged regions such as Sijunjung, one of zakat beneficiaries and impoverished areas in Indonesia. The researcher attempted a Cibest method to capture the impact of zakat beneficiaries before and after becoming a member of Zakat Community Development (ZCD) Program in material and spiritual value. The overall analysis shows that zakat has a positive impact on disadvantaged regions development and enhance the quality of life of the community. There is an improvement in the average of mustahik household incomes after becoming a member of ZCD Program. Cibest model demonstrates that material, spiritual, and absolute poverty index decreased by 10, 5, and 6 per cent. Meanwhile, the welfare index is increased by 21 per cent. These findings have significant implications for developing the quality of life in disadvantaged regions in Sijunjung. Therefore, zakat is one of the instruments to change the status of disadvantaged areas to be equivalent to other areas.

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