Monthly mean Wolf number recordet at Observatori de l'Ebre.

The Wolf number (W) is calculated on the basis of the number of groups (G) and sunspots (t) (W=10 G + t). This formula indicates that the appearance of a coherent group of sunspots (an active region) is more important that to add a few spots more to an already existing group.

YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
1943 15.5 29.3 32.0 32.1 15.7 8.2 12.3 22.1 10.2 6.4 11.8 16.8
1944 4.3 0.9 13.2 0.0 0.5 5.4 4.0 21.8 14.6 20.5 16.1 32.9
1945 21.2 16.5 23.2 35.0 33.4 47.1 48.8 31.1 36.8 80.0 58.0 29.4
1946 60.7 108.0 98.5 95.1 109.2 96.7 147.5 143.3 121.9 116.5 147.7 124.4
1947 134.5 148.8 149.5 159.1 207.3 163.3 153.9 186.3 169.1 179.2 160.4 123.0
1948 117.2 106.1 104.3 198.5 147.8 144.5 124.7 151.0 134.9 125.0 92.4 120.8
1949 115.8 167.5 153.4 151.8 117.3 120.9 120.1 124.4 138.9 137.1 143.8 116.3
1950 104.8 84.8 122.5 103.4 119.7 77.3 82.0 85.1 53.9 68.1 58.2 52.3
1951 49.1 65.4 60.9 86.9 93.1 82.0 57.9 51.7 84.3 57.7 69.2 48.6
1952 46.8 28.9 27.8 30.7 31.8 46.0 46.3 63.2 31.9 25.2 19.6 32.9
1953 27.1 5.0 13.4 24.7 12.0 25.0 8.6 27.3 19.2 10.7 3.5 3.9
1954 1.5 0.4 8.7 1.8 0.5 0.0 5.4 10.9 3.0 9.9 12.5 11.8
1955 26.8 25.4 7.9 18.0 33.4 34.9 37.5 50.0 56.0 56.6 100.5 81.1
1956 89.6 135.3 160.1 152.0 149.6 130.1 127.5 181.1 189.3 156.3 192.4 204.6
1957 172.1 140.6 191.3 204.6 173.2 188.3 185.7 165.0 232.0 275.6 221.6 255.0
1958 249.4 176.7 200.1 219.1 203.8 181.5 193.2 216.3 223.2 206.4 179.7 209.1
1959 271.0 169.5 211.9 171.6 142.1 151.4 132.1 183.6 136.1 110.3 113.7 109.4
1960 149.1 114.4 115.7 133.1 130.4 121.4 126.0 135.0 129.4 79.2 102.0 85.8
1961 56.5 55.0 61.7 69.3 53.1 70.0 60.4 44.3 56.3 38.2 36.8 46.8
1962 40.7 38.8 32.2 41.6 34.4 35.7 17.9 22.0 45.4 39.3 26.0 20.3
1963 21.2 23.0 12.8 25.9 32.6 29.9 12.9 24.2 35.0 36.5 24.5 18.0
1964 20.5 19.4 20.6 12.2 13.3 12.6 5.0 13.1 7.0 9.6 9.6 18.5
1965 25.3 20.5 18.3 12.7 28.1 18.5 14.7 10.9 22.0 22.9 20.5 19.6
1966 31.4 31.7 27.4 51.8 63.3 61.9 72.5 69.4 61.5 78.8 79.3 92.8
1967 143.4 126.9 145.8 94.8 134.5 89.4 119.3 147.2 99.5 112.5 110.8 142.5
1968 130.4 132.4 109.1 96.6 159.3 141.9 112.9 131.9 139.7 127.9 103.2 118.5
1969 110.1 126.9 177.0 142.1 164.4 128.8 127.4 119.6 114.2 123.1 119.1 118.5
1970 151.8 173.0 154.0 148.2 168.7 151.5 160.8 137.7 144.8 133.4 138.6 121.9
1971 123.3 115.7 90.7 108.6 85.7 81.6 124.2 86.3 72.4 65.0 68.6 102.4
1972 73.0 97.5 100.5 82.1 85.9 101.4 101.4 91.1 90.0 62.5 37.6 44.8
1973 41.1 41.0 50.6 65.8 50.3 48.0 32.1 31.5 66.4 32.2 24.7 22.6
1974 31.7 30.7 28.2 45.4 41.1 42.4 55.2 41.2 43.5 48.3 28.2 20.2
1975 20.6 10.9 10.1 4.5 9.2 12.8 42.1 42.9 16.3 9.1 18.6 6.7
1976 7.1 4.5 21.6 19.7 14.3 13.4 2.6 15.8 12.8 18.7 5.3 14.1
1977 19.8 23.2 6.0 7.3 17.2 38.5 21.8 34.7 54.9 50.6 34.0 47.4
1978 57.5 93.9 88.8 115.9 99.2 124.7 70.3 62.1 167.3 144.8 106.0 128.7
1979 188.9 143.5 168.3 103.0 159.9 187.2 196.3 177.3 244.5 228.3 200.8 185.2
1980 139.7 165.0 144.0 153.1 237.0 201.1 181.0 184.1 236.0 212.3 158.4 185.4
1981 117.1 149.6 172.1 226.5 214.0 127.2 204.3 276.3 270.2 210.9 186.4 162.7
1982 124.3 195.8 171.6 154.2 117.3 143.7 142.7 154.4 145.8 113.8 109.7 113.2
1983 90.2 60.1 73.3 87.6 106.7 105.7 91.9 83.7 48.8 59.2 32.4 37.9
1984 54.9 71.3 91.2 69.5 84.7 60.6 51.7 30.5 16.9 11.2 18.2 12.6
1985 8.7 17.6 11.0 14.1 24.8 27.7 39.9 7.8 3.5 19.4 13.4 14.4
1986 1.3 20.3 7.8 20.3 12.3 .0 15.8 7.9 4.4 33.3 11.8 5.2
1987 6.0 1.3 15.3 43.1 31.9 13.8 32.7 39.7 38.6 49.0 23.6 15.6
1988 38.4 38.4 71.2 101.6 66.5 124.1 110.2 117.5 142.7 161.7 139.1 171.9
1989 186.2 179.9 125.1 123.0 159.5 229.3 144.9 179.5 174.2 171.8 186.2 146.7
1990 182.7 137.7 157.6 162.5 163.3 136.2 159.1 227.4 154.5 177.0 116.0 148.5
1991 157.9 199.4 166.3 144.7 129.4 170.8 191.6 218.0 142.5 158.0 124.8 154.9
1992 151.9 186.5 112.2 101.3 67.1 76.6 89.8 74.3 75.8 108.8 99.5 91.4
1993 70.8 97.7 67.6 64.3 57.4 48.7 60.2 47.8 18.5 44.9 36.0 46.5
1994 53.2 35.1 36.1 15.8 18.5 26.9 43.8 26.0 32.8 48.2 16.8 24.7
1995 28.1 34.9 33.9 16.1 14.9 19.6 17.0 13.6 12.7 23.9 10.3 6.3
1996 8.1 2.8 10.5 3.3 5.1 13.6 7.8 15.7 1.3 .0 11.0 8.7
1997 2.4 9.5 10.7 21.4 23.0 17.3 10.3 30.3 57.4 25.6 41.5 41.1
1998 32.0 46.5 74.4 65.0 64.7 84.8 87.0 122.4 118.4 67.3 69.9 99.8
1999 58.3 74.1 87.9 76.9 146.2 210.3 164.1 133.4 101.3 145.9 146.9 88.5
2000 121.3 138.1 184.9 157.5 152.2 173.5 207.1 180.0 134.8 114.8 126.3 116.5
2001 94.1 104.9 138.8 129.1 104.7 147.1 98.4 127.6 171.4 155.1 126.4 166.9
2002 142.3 142.4 129.1 153.0 159.1 122.6 142.1 155.8 163.8 152.1 117.6 104.0
2003 108.4 83.1 90.5 91.8 81.7 115.3 130.8 112.7 69.5 95.6 62.1 72.0
2004 44.9 63.7 61.7 56.9 65.7 53.9 69.2 62.3 42.4 35.3 51.5 23.7
2005 34.3 37.6 46.7 38.4 54.1 52.5 55.4 53.2 35.7 9.9 28.3 54.3
2006 28.5 5.3 12.5 45.4 32.4 16.5 20.1 15.3 24.4 15.9 26.3 16.4
2007 26.6 14.6 5.3 5.5 13.3 19.5 15.1 8.9 3.8 1.5 1.8 12.9
2008 2.7 2.4 11.1 3.8 6.7 4.1 0.8 0.4 0.0 5.0 4.7 1.6
2009 0.7 2.1 0.0 0.0 1.7 5.7 3.1 0.0 7.8 5.1 4.4 8.6
2010 14.0 23.9 24.6 12.8 12.6 17.1 19.0 25.2 26.4 29.3 29.1 20.6
2011 27.9 30.3 62.5 67.3 52.6 46.4 56.8 56.8 102.9 109.8 128.2 97.5
2012 82.3 44.2 82.2 70.4 93.7 82.8 63.8 82.3 94.4 64.6 83.8 57.0
2013 98.2 41.8 74.7 96.1 105.8 66.1 71.9 85.4 50.1 101.2 81.2 94.2
2014 88.0  119.4 109.0 83.6 98.9 76.2 72.8 89.9 97.4 77.5 84.0 70.3
2015 73.4 49.1 34.4 62.2  71.1 55.4  58.4 42.8   51.0  43.9  40.2  39.2
2016 35.1 ------ ------ ------ ------ ------ ------ ----- ----- ----- ------ -----
2017 ------ ------ ------ ------ 12.0 16.5 13.2 28.9 35.3 10.9 3.5 0.8
2018 2.8 11.6 0.0 6.9 6.0 10.0 0.0 3.8 0.6 3.6 0.0 0.9
2019 5.0 0.0 6.8 5.1 8.0 0.0 0.0 1.0 0.6  0.0  0.0 2.2 
2020 3.0 0.0 1.1 1.6 0.0 1.6 6.2 2.9 0.0 7.6 15.5 16.4
2021 4.6  3.8 8.1 7.5                



Since its foundation in 1904, l'Observatori de l'Ebre (OE) has operated, virtually uninterruptedly, different seismographs, being the oldest seismic station in Catalonia. Throughout the years more than 20 seismographs have been in operation. From the first Grablovitz, which was installed in 1904, to the last Wielandt-Strecksein STS-2 with a 24-Bit Quanterra Q680-LV digitizer, a large number of records have been accumulated, mostly on paper (the first in smoked paper, then photo paper, ink and thermal paper) and the most modern ones in digital format.

It took a great effort for the conservation and dissemination of this valuable and voluminous heritage, more than 100,000 seismograms, which the OE could not address by itself. It is with this intention, among others, that in June 2016 a collaboration agreement was signed between the OE and the Institut Cartogràfic i Geològic de Catalunya (ICGC), which is the dependent entity of the Department of Territory and Sustainability with competences on seismology and cartography, through which the scanning of the OE seismograms was started. This agreement has been renewed in 2017 and 2018 and has allowed the digitization of some series of seismograms, as well as the modernization of the OE seismic station.

The digitized seismograms can be visualized by selecting the name of the instrument in the following table, which in turn shows the different instrumentation that has been operating over the years in the OE. The links will lead you to ICGC pages, where the different seismograms are housed and where the conditions of use and the appointment of the sources are reported.

Instrument  Years Type

Period

(s)

Components

Mass

(kg)

Recording 

rvelocity

(mm/minute)

Amplificaction
Grablovitz 1904-1918 M 13 NE-SW/NW-SE 12 5 8
Vicentini Vertical 1904-1936 M 13 Z 50 15 150
Microsismograph Vicentini 1904-1916 M 0.85 N-S 100 15 90
1904-1928 M 2.3 E-W 100 15 90
MainkaEbre 1914-1941 M 14.8 N-S 1501 12 200
Mainka Ebre 1914-1938 M 7.8 E-W 157 12 110
Vertical pendulum Ebre 1914-1915 M (2.5) NE-SW/NW-SE 316 12  
Vertical pendulum Ebre 1915-1941 M 2.6 N-S 316 12  125
Mainka Ebre N-S 1942-1966 M 15.4 N-S 1500 12 275
Mainka Ebre E-W 1942-1966 M 10.8 E-W 1500 12 150
Vertical pendulum 1943-1961 M 2.5 N-S 635 12 230
Zenithal pendulum 1961-1966 M   Z 635 12  
Geotech 6102A + Lehner-Griffith GL-261 1965 -1967  E 15 N-S 15 60 50000
Geotech 6102A + Lehner-Griffith GL-261 1965-1967 E 15 E-W 15 60 50000
Geotech 4681A 1966-1974 E 15 Z 15 60 50000
Geotech6102A 1966-1974 E 15 N-S 15 60 50000
Geotech6102A 1966-1974 E 15 E-W 15 60 50000
Sprengnether S-5000V  1969-1974   E 1.0 11.2  15  1500
Sprengnether S-5000H  1968-2000 E 1.0 N-S 10.7 15 1500
Sprengnether S-5000H 1968-2000 E 1.0 E-W 10.7 15 1500
Sprengnether S-5000V  1974-2000 E 1.0 Z 11.2 15 1500
SS-1 Ranger EROQ 1987-2003 E 1.0 Z 1.45 60  
SS-1 Ranger EROQ 1991-2003 E 1.0 N-S 1.45 60  
SS-1 Ranger EROQ 1991-2003 E 1.0 E-W 1.45 60  

 

Table adapted form  Batlló & Ugalde, 2000 (Els sismografs de l'Observatori de l'Ebre. Actes de les V Trobades d'Història de la Ciència i de la Tècnica, Barcelona, Spain, 161-165). Type: M mechanical, E electromagnetic. 

DSCF0554Monitoring the magnetic field and the status of the ionosphere in Antarctica is an important issue for the contribution it yields to modeling a number of phenomena concerning the geophysical sciences. Geomagnetic observatories are ground-based stations aimed at monitoring the natural magnetic field over time (typically for as many years as possible) in a fixed location. Data from observatories reveal the magnetic field variations in a wide range of time scales, from seconds to centuries, which is important for understanding processes both inside and outside the Earth. Geomagnetic activity is triggered and modulated by the Solar Activity. And the ionosphere, that region of the upper atmosphere which influences radio propagation to distant places on the Earth, is also bounded by the Sun and the geomagnetic field.

ant04Livingston Island Geomagnetic Observatory is part of a global network currently having more than 170 active geomagnetic observatories all over the world. Because of its remoteness, it is a partly manned observatory, meaning that it is attended by the scientific and technical staff only a part of the year, typically from December to February, coinciding with the austral summer. It started in December 1996 with the current geomagnetic station, though new instrumentation has gradually been added up to fulfill the evolving standards of observation. An ionospheric sounder was incorporated during the 2004-2005 Antarctic survey with the installation of vertical incidence emitting and receiving antennas and their control electronics.

 

Ant antena

santidiflux

 

The relative low density of geophysical data around the Antarctic gives our observatory an added value. In addition, having long data series in a given location provides information on the time evolution of the physical magnitude being measured, which is essential to many studies, such as those related to the secular variation of the main magnetic field, to the seasonal variations of both the magnetic field and the ionospheric parameters or those related to the 11-year solar cycle variation on both. The availability of more than 15 years of geomagnetic data, for example, enables to average out transient effects in magnetic and ionospheric data, which otherwise would be biased by natural reasons, or at least provide an incomplete vision of the real behavior. The aim of the observatory is thus to monitor both the geomagnetic and ionospheric activity and to send the data to Spain at any time so it can be analyzed and processed in real-time even when the Spanish Antarctic Base "Juan Carlos I" is unattended during the austral winter.

 

DSC07207

 

You can get more information on the geomagnetic measuring instruments and data processing in online bulletins. For the data, please consult the World Data Centres (eg WDC Edinburgh), our catalogues (Livingston data catalogues) or view the magnetograms (Livingston magnetograms) and ionograms (Livingston ionograms).

If you want to know more about our expeditions in Antarctica, read this news item, this El Pais blog entry #Somos Antártida, or watch the interview of Ben Trobats of El Punt Avui+ on 12 January 2016. Following you also will find the video "Observatori de l'Ebre, 20 anys investigant el camp magnètic a l'Antàrtida", produced by Antena Caro.

 

K-index of geomagnetic activity calculated from our data. (Unrevised automatic process)
27-08-21
28-08-21
Photographs of the solar photosphere taken with our own telescope
The compass is oriented according to the magnetic north, not the true one. The magnetic north varies with time. Over the past centuries, in Roquetes, compasses were deviated westward. But this has changed and now they are deviated eastward More information.

17/09/2021 05:20
Temperature Humidity Atmospheric pressure
19.2 ºC 77.6 % 1010.7 hPa
Accumulated rain Wind speed Wind bearing
0 mm 8 km/h N (5º)
Information from the automatic station of AEMET located at Ebro Observatory. These data are provisional and subject to revision.