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24 June 2009

Case Analysis of Relationship between Rainfall Convection and Flood Phenomena on January 2002 in DKI-Jakarta Area


International Conference on Mathematics and Natural Sciences (ICMNS)
November 29-30, 2006, Bandung-Indonesia

Case Analysis of Relationship between Rainfall Convection and Flood
Phenomena on January 2002 in DKI-Jakarta Area



Rahmat Gernowo 1 ; Bayong Tj. H.K. 2; The Houw Liong 3; Tri Wahyu Hadi 4 ; Ina Juaeni 5
1 Faculty of Mathematics and Natural Sciences, Diponegoro University, Semarang
Jl. Prof. Sudarto, Tembalang Semarang.
2,4 Expertise of Atmosphere Science Group, Bandung Institute of Technology
3 Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology
5 Faculty of Earth Science and Mineral Technology, Bandung Institute of Technology
Jl. Ganesha No. 10 Bandung 40132
*Email: gernowo1@yahoo.com

Abstract
The dynamics of cloud rain especially in area of Jakarta represent to important matter in seeking of step solution, to prevention of floods especially in Jakarta. The research of convection pattern above area of DKI-Jakarta based on to existing perception data, especially high resolution satellite image which is expected will give the understanding of growth of convection cloud yield torrential rains and deliver floods in DKI-Jakarta.The result of research into whereas in this research is obtained by the study of extreme rainfall in DKI-Jakarta. As rainfall data result of average from some stations is residing in DKI-Jakarta.
The rainfall data taken end 2001- early 2002 year, where happened the floods with pond more than 10 day source data of Kimpraswil-Cilsi. The result of research is obtained by analysis whereas, that cloud dynamics in DKI-Jakarta caused by local atmospheric circulation’s factor.
Keywords : Flood, cloud dynamics and satellite image.

Regional Climate Model WRF for Analyzing Extreme Rainfall in DKI-Jakarta


JTM vol. XIV, No. 4/2008, FIKTM, ITB, Bandung

MODEL CUACA REGIONAL WRF UNTUK ANALISA DINAMIKA AWAN KEJADIAN HUJAN EKSTREM DKI-JAKARTA
; Studi Kasus Februari 2007


by

Rahmat Gernowo *; The Houw Liong**; Tri W.Hadi ***; N.J. Trilaksono ****

Abstract

The WRF (Weather Research and Forecast) model usage to simulated the most of atmosphere dynamics at the same time cumulus parameter through to the condition of rainfall cumulus simulation when floods on February 2007 in DKI-JAKARTA.

The Result of this research is a numerical simulation dynamics of cloud rain especially in area of Jakarta represent to important matter in seeking of step solution the prevention of floods especially in Jakarta. The research of convection pattern above area of DKI Jakarta based on to existing perception data, especially high resolution satellite image which is expected will give the understanding of pattern growth of convection cloud yield torrential rains and deliver floods in DKI-JAKARTA.

Key Words: Flood, cloud dynamics and satellite image.


Sari

Penggunaan model WRF (Weather Research and Forecast) untuk mensimulasikan sebagian besar dinamika atmosfer sekaligus parameterisasi cumulus dan simulasi kondisi curah hujan cumulus saat banjir Bulan Februari 2007 di DKI-Jakarta.

Hasil penelitian ini adalah simulasi numerik dinamika awan hujan khususnya daerah Jakarta, merupakan hal penting dalam pencarian salah satu solusi langkah penanggulangan banjir khususnya daerah Jakarta. Pengkajian terhadap pola konveksi di atas daerah DKI Jakarta berdasarkan data pengamatan yang ada, terutama citra satelit resolusi tinggi hal mana diharapakan akan memberikan pemahaman mengenai pola pertumbuhan awan konveksi yang menghasilkan hujan lebat dan mendatangkan banjir di wilayah DKI-Jakarta.

Kata Kunci : Banjir, dinamika awan dan citra satelit.

* Fakultas MIPA Jurusan Fisika Universitas Diponegoro Semarang
**Fakultas MIPA Jurusan Fisika Institut Teknologi Bandung
***,**** Kelompok Keahlian Sains Atmosfer, Instiut Teknologi Bandung

21 June 2009

ATMOSPHERE DYNAMICS OF EXTREME RAINFALL AND THE PRELIMINARY EVALUATION OF WEATHER MODIFICATION STATIC SYSTEM IN DKI-JAKARTA

ATMOSPHERE DYNAMICS OF EXTREME RAINFALL AND THE PRELIMINARY EVALUATION OF WEATHER MODIFICATION STATIC SYSTEM IN DKI-JAKARTA

By
RAHMAT GERNOWO
NIM 32404001
Promotor: Prof. Dr. Bayong Tjasyono H. K.
Co-Promotor: Prof Dr. The Houw Liong
Co-Promotor: Dr. Tri Wahyu Hadi

ABSTRACT

DKI-Jakarta is a part of Java Island which geographically lies between the Java Sea and the Indian Ocean. This geographical location leads to the forming of convective cloud which will result to the formation of heavy rain (shower). Jakarta area and its surroundings are hit by floods every year due to torrential rain. Among them, the worst cases are the flood that hits on 2002 and 2007, where the floods natural disaster swept over approximately 70% of Jakarta area.

One approach to solve the floods problem is to understand fundamentally the factors that cause floods, through precursor analysis of extreme rainfall and application of its corresponding technology. The understanding about atmosphere dynamics pattern in DKI-Jakarta is required, because the process causes changes in the fluctuation pattern of the rainfall. The study of cloud dynamics analysis will explain the occurrence of extreme rainfall which causes floods. The weather modification technology of Ground Based Generator (GBG) model adjustment is expected decreasing the extreme rainfall intensity.

The result of atmosphere dynamics analysis on extreme rainfall phenomena in DKI Jakarta region for the flood case periods on 2002 and 2007 shows the existence of an equal pattern of i.e. cold surge and strong vortex. As the local effect influence analysis, these two factors caused the updraft which results to the growth of deep convective cloud. The analysis of Madden-Julian Oscillation (MJO) and anomaly of Multivariate ENSO Index (MEI) indicates non dominant factor compared to the influence of Indian Ocean Dipole (IOD) to flood phenomena. The cloud pattern characteristic in the case of Jakarta floods from calculation of convective index either from outgoing Longwave Radiation (OLR) and Infra Red channel 1 (IR 1) temperature data in DKI Jakarta shows the growth of convective cloud is localized around Jakarta. As the two factors global analysis i.e. the sun activity and cosmic ray flux become the dominant factor of extreme rainfall in DKI Jakarta. This is based on the correlation between the years of flood occurrence, reanalysis of maximum rainfall in Jakarta to sunspot index and interrelationship variability between to cosmic ray flux with cloud cover.
The simulation of cloud dynamics in DKI-JAKARTA on 2007 was based on the Weather Research and Forecast (WRF) model with Final Analysis (FNL) data which takes global data as model input. The validation of extreme rainfall simulation with spatial rainfall data from BMKG (The Agency of Meteorology, Climatology and Geophysics) resulted to the correlation coefficient of 0.7. The cloud simulation analysis indicated the growth of deep convective cloud in extreme rainfall. The simulation of wind vector and the vertical temperature change from WRF model output applied to Ground Based Generator (GBG) model input. The result shows that movement vector of seeding material concentration to the based of cloud is 12.6 g/m3. As the validation of above result concentration calculation of seeding material with WRF model where obtained the minimum concentration is 150 g/m3 for the cloud to start growing.

Key Word: Flood, cloud dynamics, WRF model and weather modification.

20 June 2009

CHARACTERISTICS, MECHANISMS, AND TEMPORAL MODEL OF HYDROMETEOROLOGY IN THE UPPER AND MIDDLE CITARUM RIVER BASIN

CHARACTERISTICS, MECHANISMS, AND TEMPORAL MODEL OF HYDROMETEOROLOGY IN THE UPPER AND MIDDLE CITARUM RIVER BASIN

PhD Theses from JBPTITBPP / 2008-07-22 14:55:45
Oleh : RUMINTA (NIM 32403003), S3 - Engineering Sciences
Promotor: Prof. Dr. Bayong Tjasyono, H.K., DEA.
CO-Promotor : Prof. Dr. The Houw Liong, Dr. Ir. Indratmo Soekarno

Keyword : rainfall, discharge, global phenomena, wet and dry periods, chaotic mono-fractal, return periods, cyclic, long-term trends, ANFIS, temporal models

A study on characteristics, mechanisms, and temporal models of the hydrometeorology was carried out in the Upper and Middle Citarum River Basin, West Java. The investigations based on monthly observations data of the rainfall, evapotranspiration, humidity, and river discharge from January 1968 to December 2000 and monthly data of global phenomena from reanalysis National Centers for Environmental Prediction (NCEP) and National Geophysical Data Center (NGDC). Identification of hydrometeorolgical components characteristics was based on statistics analysis i.e., cumulative sum (CUSUM), variability, correlation dimension, empirical probability, return periods, power spectrum, long-term trends, and sensitivity. While identification of the temporal dynamical model of the hydrometeorology based on Adaptive Neuro-Fuzzy Inference System (ANFIS) analyses. The results indicated that rainfall had two firm persistence i.e. wet and dry periods. The rainfall and river discharge have very high variability i.e., 73% and 62%, respectively. These data indicated that the processes of the rainfall and river discharge were very chaotic. Variability patterns of the rainfall and river discharge had increasing trends, the facts indicated that drought and flood events can to be extreme. The hydrometeorological processes in the Citarum river basin was low-dimension chaotic (correlation dimension <4). The values of the rainfall, evapotranspiration, humidity, and river discharge are 1.83, 1.68, 1.23, and 2.05 respectively that showed a minimum numbers of the main variables in the dynamic model of the hidrometeorological processes are 2, 2, 2, and 3 respectively. The rainfall and river discharge are chaotic mono-fractal (qD<2) that showed deterministic processes but the evapotranspiration and humidity are chaotic multi-fractal (qD>2) that showed stochastic processes. The extreme values of the rainfall and river discharge had return periods i.e., 5 and 25 months respectively. The rainfall and river discharge had the same three main cyclic there are 5-7, 9-25, and 100-125 monthly. The facts indicated that rainfall and river discharge had controlled by monsoon, quasi biennial, and sunspot oscillations. The hydrometeorological processes in the Citarum river basin was the results of the unbounded cascade processes because that had the value of exponent spectrum (B) less than one. The rainfall and river discharge had been decreased by about 3.64% and 1.11% respectively for every a hundred months. The decreasing trend in the rainfall and river discharge had controlled mainly by the decreasing of the clouds and convection rains formation as a consequence of the deforestation and global climate variability. The evapotranspiration and air humidity had been increased by about 3.88% and 4.21% respectively for every a hundred months. The increasing trend in the evapotranspiration and air humidity had been influenced by the increasing of the water vapour removal from vegetation lands surface to the atmosphere by both evaporation and transpiration. The river discharge is very sensitively against the rainfall's fluctuation, especially in June-July-August periods. Water storages had been decreased and coefficient of runoff had been increased, that facts indicated that reservoirs while land cover by vegetation had been decreased so that drought and flood events can to be extreme. The rainfall and river discharge in the Upper and Middle Citarum River Basin were influenced by global phenomena, especially Global Temperature, Indian Oceans Dipole Mode, Southern Oscillation, Indian Monsoon, and Precipitable Water. The temporal dynamical model of the hydrometeorology based on ANFIS can simulate the observations data accurately. The model is capable to minimize the bias and root mean squared error (RMSE) values and maximize the precision (E) value. Annually temporal models can predict more accurately rainfall and river discharge than theses of the monthly temporal models. The hydro-meteorological temporal model results of the ANFIS indentification very potential used to predict the rainfall and run off. The results of study on characteristics, mechanisms, and temporal models of the hydrometeorology can give an information for improvement of an integrated water management in the Citarum River Basin.

Copyrights : 2001 by ITB Central Library. Verbatim copying and distribution of this entire article is permitted by author in any medium, provided this notice is preserved.

Floods Phenomena and Disaster Mitigation

Floods Phenomena and Disaster Mitigation
Banjir dan Mitigasi Bencana



Perbandingan Analisis Dinamika Atmosfer pada Fenomena Banjir Tahun 2002 dan 2007 DKI Jakarta Sebagai Alternatif Mitigasi Bencana Alam

Rahmat Gernowo, Bayong Tj. H.K., The Houw Liong, Tri W.H., Ruminta
[Vol. 10, No. 2, Juli 2008, Bionatura]

Dinamika awan hujan khususnya daerah Jakarta, merupakan hal penting dalam pencarian salah satu solusi langkah penanggulangan banjir khususnya daerah Jakarta. Kajian terhadap pola konveksi di atas daerah DKI Jakarta berdasarkan data pengamatan yang ada, terutama citra satelit resolusi tinggi hal mana akan memberikan pemahaman mengenai pola pertumbuhan awan konveksi yang menghasilkan hujan lebat dan mendatangkan banjir di wilayah DKI-Jakarta. Dalam penelitian ini, dilakukan kajian hujan ekstrim di DKI Jakarta. Fenomena tersebut dianalisis berdasarkan efek dinamika atmosfer baik dari skala global, regional dan lokal. Diperoleh hasil bahwa dinamika awan di DKI Jakarta saat terjadi hujan ekstrim tahun 2002 dan 2007 didominasi oleh faktor sirkulasi atmosfer lokal dengan pola yang sama. Pola berulang dari dinamika atmosfer ini, dapat digunakan sebagai alternatif proses pembelajaran dan mitigasi bencana alam kedepan sedemikian sehingga akan meminimalisasi kerugian.

COMPARISON OF ATMOSPHERE DYNAMICS ANALYSIS AT FLOODS PHENOMENON ON THE YEAR 2002 AND 2007 IN DKI JAKARTA AS ALTERNATIVELY OF NATURAL DISASTER MITIGATION

The dynamics of cloud rain especially in area of Jakarta is an important matter in seeking solution to prevent floods especially in Jakarta. The research of convection pattern above area of DKI Jakarta based on the existing perception data, especially high resolution satellite image which is expected to give the understanding of pattern growth of convection cloud that yield torrential rains and deliver floods in DKI-Jakarta. In this research the rain extreme study in DKI Jakarta was conducted. The phenomenon is analyzed based on atmosphere dynamics effect either from global, regional and local scale. The research result indicated that the cloud dynamics in DKI Jakarta when extreme rain occurred in 2002 and 2007 predominated by local circulation atmosphere factor with the same pattern. The repeating pattern from this atmosphere dynamics, serve the purpose of alternative to study process and mitigations of natural disaster to the future in such a way that will be minimized the loss.

MODEL PREDIKSI CURAH HUJAN BERBASIS TRANSFORMASI WAVELET DAN SISTEM INFERENSI FUZZY JARINGAN SARAF ADAPTIF

MODEL PREDIKSI CURAH HUJAN BERBASIS TRANSFORMASI WAVELET DAN SISTEM INFERENSI FUZZY JARINGAN SARAF ADAPTIF


Oleh: Rahmat Gernowo
NIM: 204980006
S2 - Oceanography and Atmospheric Sciences
Dibuat: 2000-09-00 , dengan 1 file(s).

Keywords:
Modeling, Learning, Estimation

Subject:
Geology, Hydrology, Meteorology
Call Number: T 551.647 7 GER

Abstrak :

Telah dilakukan studi model prediksi dari data curah hujan (khususnya Pulau Jawa) dengan model transformasi Wavelet dan sistem Inferensi Fuzzy jaringan saraf adaptif (ANFIS), untuk pengolahan data eurah hujan dalam kurun waktu 10 tahun (tahun 1988 -- 1998) sebagai data historis pada proses pembelajaran. Perangkat lunak yang dimanfaatkan antara lain WWZ (Weighted Wavelet Z-transform), Wavelet Analyzer dan ANFIS.

Hasil yang diperoleh, baik dengan transformasi wavelet maupun sistem fuzzy menunjukan jangkauan estimasi yang sama ; rata-rata estimasi untuk seluruh daerah penelitian diperoleh sebesar 90,12 % untuk pengolahan dengan wavelet, adapun untuk pengolahan dengan arfis diperoleh 89,51 %. Variabilitas curah hujan untuk kedua model, khususnya daerah pengamatan pulau Jawa menunjukan pota curah hujan monsunal yaitu curah hujan terlinggi ada pada awal dan akhir pentad dan mulai menurun hingga pertengahan pentad.

Abstract :

Study of rainfall-data prediction modeling has been done by using Wavelet transform model and ANFIS. As history data (Java Island in particular) in learning process was taken from 10 years period (from 1988 to 1998). The Weighted wavelet Z transform, the Wavelet Analyzer and ANFIS software was applied in the analysis.

The wavelet transform and ANFIS processing result show the same range of estimation, with average estimation of the all experiment zone are 90,12 % by wavelet transform processing and 89,51 % by ANFIS processing. Rainfall variability of the two modeling processing with the special of Java Island shows the monsoon rainfall pattern that reach top level at the first and final pentad and decrease until the middle pentad.

17 June 2009

FINITE ELEMENT METHOD TO VISUALIZE FLOW PATTERN AND TEMPERATURE DISTRIBUTION

SIGMA Jurnal Sains dan Teknologi, Vol 7, No 1 (2004)

FINITE ELEMENT METHOD TO VISUALIZE FLOW PATTERN AND TEMPERATURE DISTRIBUTION IN TWO-DIMENSIONAL LIQUID-DOMINATED GEOTHERMAL SYSTEM
Yosaphat Sumardi, The Houw Liong, Srijatno Wirjosoedirdjo, Alamta Singarimbun


Abstract


The finite element method is used to visualize the development of flow pattern and temperature distribution in two-dimensional liquid-dominated geothermal system. This system is assumed as a homogenous porous host rock that is fully saturated by pure water. FEMLAB software is used to solve the differential equations of flow and transport simultaneously. The different flow pattern and temperature distribution appear with increasing simulation time.
Keywords: Finite element method, flow pattern, temperature distribution, two-dimensional liquid-dominated geothermal system

Full Text: Subscribers Only

12 June 2009

Ionospheric Precursors of December 26, 2004 Sumatran Earthquake As Seen From GPS Data

Ionospheric Precursors of Sumatran Earthquake from GPS Data.
Ionospheric Precursors of December 26, 2004 Sumatran Earthquake As Seen From GPS Data


Buldan Muslim, Hasanuddin Z. Abidin, Wedyanto Kuntjoro, The Houw Liong, Asnawi

(ITB-LAPAN)

Sumatran GPS Array (SUGAR) data have been used to study ionospheric precursors of December 26, 2004 earthquake at Aceh, Sumatran Island, Indonesia. We use GPS signal carrier phase and pseudorange code observation derive daily vertical total electron content (TEC).

Cross-correlation analysis of daily TEC from GPS station inside seismic zone with TEC from GPS station outside seismic zone from 21-31 December shown that several days before earthquake, their mutual correlations are significantly decrease. It can be interpretated that seismic activity near epicenter affect ionospheric variability. Remarkably, on December 24, 2007, the cross-correlation of COCO site to SUGAR were to be the lowest value of each, while COCO-BAKO cross-correlation was not decreasing.

Statistically, it have proven that several days before the seismic shock the level ionospheric variability increases at station closest to the epicenter, a fact which can be regarded as precursory phenomenon. By development of GPS observation around the world rapidly, ionospheric precursors from GPS observation around the world rapidly, ionospheric precursors from GPS data can be combined with other precursors so will be potential in the future for requirements of short term prediction of earthquake.

03 June 2009

Weather/Climate Regional Model in Indonesia


Weather/Climate Regional Model in Indonesia
Based on Terrestrial Effects of Solar Activity

Plato M. Siregar 1) Deni Septiadi 2) The Houw Liong 3)

1) Science Atmosphere Division, Faculty of Earth Science and Mineral Technology, ITB
2) Climatology Station of Siantan Pontianak, Meteorological and Geophysical Agency, BMG
3) Physics of Complex System Division, Faculty of Mathematics and Natural Sciences, ITB

BMKG Symposium, Jakarta 2008



ABSTRACT

Weather/Climate in Indonesia is influenced by four main quasi periodic cycles: Solar Activity Cycle (Sunspot Numbers Cycle), Galactic Cosmic Ray Cycle, El Nino Southern Oscillation (ENSO) Cycle, and Indian Ocean Dipole Mode (IOD) Cycle. It can be shown that solar activity cycle can be considered as primary cycle that influence other cycles. In practice eastern Indonesian region is dominantly influenced by ENSO. When the heat pools moves to eastern Indonesian region, then rainfall in this region will be above normal. On the other hand when the heat pool leaves eastern Indonesian region and moves to Pacific Ocean then the rainfall in this region will be below normal.
During a typical Indian Ocean Dipole Mode (IOD) event the weakening and reversal of winds in the central equatorial Indian Ocean lead to the development of unusually warm sea surface temperatures in the western Indian Ocean. IOD negative means wet condition or the rainfall will be above normal along the western Indonesian region.
Precipitation in Pontianak region which represent middle Indonesian region correlated strongly with sunspot numbers cycle (solar activity cycle) has been proven using observation of rainfall data in west Kalimantan.
Using ANFIS (Adaptive Neuro Fuzzy Inference System) we are able to predict sunspot numbers cycles so that extreme weather in Indonesian regions can be predicted.
Fuzzy c-means is used to classify regions that are influenced strongly by sunspot numbers (solar activity), IOD, and ENSO cycles. This method is based on fuzzy set as fuzzy c-partition of three cycles above and as cluster center. Fuzzy c-partition matrix for grouping a collection of n data set into c classes.
This study explores the physical of climate predictions and classifications of Indonesian regions and its physical interpretations.

Keywords : ANFIS, fuzzy clustering, climate, solar activity


1. Introduction

Weather/climate model always being interest topic to explored, even no one can give high accuracy and stable that applicable for different of time and space. This model especially for predicting necessary, needs involving complex parameters of weather/climate. Although that condition, weather/climate prediction technique indicated significant progress. The pattern not only limit by statistics approach but dispersion as mathematics through computation technique.
Quantitative Forecast of Precipitation (QPF) could make by subjective prediction technique, statistics prediction technique, and dynamic prediction technique. Subjective prediction technique making by experience, expertise and forecaster comprehension. Statistics prediction technique making by statistics prosedure, mean while, dynamic prediction technique make based on equations solution of simplified atmosphere processes [Rainbird, 1970].
Weather/Climate model can be constructed by using the law of physics for the atmosphere i.e.: The Navier-Stokes equation, the conservation of mass, the conservation of energy, the equations of states, including schemes for cloud formations, carbon and sulfur cycle, interactions between atmosphere and land surface, oceans, cryosphere, and biosphere, furthermore we have to include forcing by volcanic eruptions, the solar activity and galactic cosmic rays.
Researchers from LAPAN using GCM and DARLAM have reported some results of climate prediction for Indonesian regions [Ratag, 2002]. Under a scenario that CO2 concentration doubled in 100 years then the temperature in Indonesian regions will increase on the average about 0.03 degrees Celsius per year. This research showed that the result of prediction of rainfall in these regions is still poor (the correlations on the average are below 0.5) and need some modification on cloud formation scheme.
The relative positions of the sun in the sky during the seasons, as well as the cycles of solar activity influence the weather and climate throughout the Indonesian archipelago. Solar irradiance and ultraviolet intensity increases with higher solar activity. This in turn will be followed by coronal mass ejection (CME) that increases the charged particles emitted by the sun which could alter the interplanetary magnetic field, and hence the intensity of galactic cosmic rays reaching the earth. The galactic cosmic ray intensity reaching the earth decreases with higher solar activity. Thus the solar activity is often considered as the dominant factor that determines the dynamics of climate [Svensmark, 2007; Landscheidt, 1988]. The dynamics of earth's atmosphere and oceans, evaporation, clouds formation and rainfall, are influenced by the solar energy entering the earth. Several studies indicate that strong correlations exist between the cloud cover and the intensity of galactic cosmic ray reaching the earth [Carlslaw, 2002].
During 1645 – 1715 exceptionally low solar activity (also known as the Maunder minimum) which means high intensity of galactic cosmic ray reached the earth increased cloud cover that led to low temperatures causing what is known as the little ice age.
The present study shows that there is a strong correlation between rainfall in the middle Indonesian region and solar activity and the relation of solar activity and rainfall of other regions. Using this fact we can predict the climate in Indonesian regions by predicting the sunspot numbers (solar activity). It can be shown that to get a good accuracy of predicting a quasi periodic time series as sunspot numbers is possible.
The possibility of reducing the negative effect of climate using weather modification methods is also considered.


2. Data Used

This research using monthly rainfall data (mm) collected by 5 raingauges in West Kalimantan (BMKG) with 46 years length of data (1961-2006). Additionally data are monthly sunspot and cosmic rays data (1961-2006) of Royal Observatory of Belgium and Sunspot Index Data Center at http://www.astro.oma.be/SIDC.