BRITISH GEOLOGICAL SURVEY Port Stanley Observatory Monthly Magnetic Bulletin January 2020 20/01/PS
d Jason Islands Caracass Island West Falkland SaundersKeppel Island Islan King George Bay Mount Port Salavador Adam Queen Charlotte Bay Mount Osborne Berkley 700m Sapper Hill Sound 705m Weddell Darwin Stanley Goose Island Choiseul Falkland SoundGreen Sound
Port Stephens
Bay of East Falkland Harbours Eagle Passage Falkland Islands
©Crown copyright; Ordnance Survey PORT STANLEY OBSERVATORY MAGNETIC DATA
1. Introduction The geographical coordinates are measured by a handheld GPS device, which uses WGS84 as the the Port Stanley observatory was installed by the British reference coordinate system. The height above Geological Survey (BGS) with financial support MSL is determined from the best available contour from a consortium of oil companies and became maps. The geomagnetic co-ordinates are operational in February 1994. approximations, calculated using the 13th generation International Geomagnetic Reference This bulletin is published to provide rapid access to Field (IGRF) at epoch 2020.5. On-line access to the provisional geomagnetic observatory results. models (including IGRF), charts and navigational The information is freely available for personal, data are available at academic, educational and non-commercial http://www.geomag.bgs.ac.uk/data_service/models research or use. Magnetic observatory data are _compass/home presented as a series of plots of one-minute, hourly and daily values, followed by tabulations of monthly 3. The Observatory Operation values. The operation of the observatory and presentation of data are described in the rest of this 3.1 GDAS section. The observatory operates under the control of the Geomagnetic Data Acquisition System (GDAS), Enquiries about the data should be addressed to: which was developed by BGS staff, installed and became operational in August 2002. The data Geomagnetism Team acquisition software, running on QNX operated British Geological Survey computers, controls the data logging and the Lyell Centre, Heriot Watt University Research Avenue South communications. Edinburgh EH9 3LA Scotland, UK There are two sets of sensors used for making magnetic measurements. A tri-axial linear-core Tel: +44 (0) 131 667 1000 E-mail: [email protected] fluxgate magnetometer, manufactured by the Internet: www.geomag.bgs.ac.uk Danish Meteorological Institute, is used to measure the variations in the horizontal (H) and vertical (Z) 2. Position components of the field. The third sensor is oriented perpendicular to these, and measures variations, Port Stanley Observatory, one of the geomagnetic which are proportional to the changes in declination observatories maintained and operated by the (D). Measurements are made at a rate of 1 Hz. British Geological Survey (BGS), is situated on a site at Sapper Hill near Port Stanley in the Falkland In addition to the fluxgate sensors there is a proton Islands. In 2013 it was necessary to establish a new precession magnetometer (PPM) making position for the observatory absolute pillar due to measurements of the absolute total field intensity degradation in the quality of absolute observations (F) at a rate of 0.1Hz. caused by anthropogenic noise. Following an overlap period of at least six months, the The raw unfiltered data are retrieved automatically observatory results relate to the new position from 1 via Internet connections to the BGS office in January 2014. Edinburgh in near real-time. The fluxgate data are filtered to produce one-minute values using a 61- Old observatory co-ordinates are (Feb 1994 to Dec point cosine filter and the total field intensity 2013: samples are filtered using a 7-point cosine filter. The Geographic: 51°42’15”S 302°06’24”E one-minute values provide input for various data Height above mean sea level: 135 m products, available on-line at www.geomag.bgs.ac.uk/data_service/home New observatory co-ordinates are (Jan 2014 to present): 3.2 Absolute Observations Geographic: 51°42’18.0”S 302°06’25.2”E The GDAS fluxgate magnetometers accurately Geomagnetic: 42°34’41”S 012°24’00”E measure variations in the components of the Height above mean sea level: 130 m geomagnetic field, but not the absolute magnitudes. Two sets of absolute measurements of the field are made manually twice per month. A fluxgate sensor mounted on a theodolite is used to determine D and 4.4 Hourly Mean Value Plots inclination (I); the GDAS PPM measurements, with Hourly mean values of D, H and Z for the past 12 a site difference correction applied, are used for F. months are plotted in 27-day segments The absolute observations are used in conjunction corresponding to the Bartels solar rotation number. with the GDAS variometer measurements to Magnetic disturbances associated with active produce a continuous record of the absolute values regions and/or coronal holes on the Sun may recur of the geomagnetic field elements as if they had after 27 days: the same is true for been measured at the observatory reference pillar. geomagneticallyuiet intervals. Plotting the data in this way highlights this recurrence. Diurnal 4. Observatory Results variations are also clear in these plots and the amplitude changes throughout the year highlight the The data presented in the bulletin are in the form of seasonal changes. Longer term secular variation is plots and tabulations described in the following also illustrated. sections. 4.5 Daily and Monthly Mean Values 4.1 Absolute Observations Daily mean values of D, H, Z and F are plotted The absolute observation measurements made throughout the year. In addition, a table of monthly during the month are tabulated. Also included are mean values of all the geomagnetic elements is the corresponding baseline values, which are the provided. These values depend on accurate differences between the absolute measurements and specification of the fluxgate sensor baselines. It is the variometer measurements of D, H and Z (in the anticipated that these provisional values will not be sense absolute−variometer). These are also plotted altered by more than a few nT or tenths of (markers) along with the derived preliminary daily arcminutes before being made definitive at the end baseline values (line) throughout the year. Daily of the year. mean differences between the measured absolute F and the F computed from the baseline corrected H 5. Conditions of Use and Z values are plotted in the fourth panel (in the sense measured−derived). The bottom panel shows The data presented in this bulletin are provided for the daily mean temperature in the fluxgate personal, academic, educational, non-commercial chamber. research or other non-commercial use and are not for sale or distribution to third parties without written 4.2 Summary magnetograms permission from BGS. Small-scale magnetograms are plotted which allow the month's data to be viewed at a glance. They are Reproduction of any part of this bulletin should be plotted 16 days to a page and show the one-minute accompanied by the statement: 'Reproduced with variations in D, H and Z. The scales are shown on the permission of the British Geological Survey the right-hand side of the page. On disturbed days ©NERC. All rights Reserved'. Publications making the scales are multiplied by a factor, which is use of the data should include an acknowledgment indicated above the panel for that day. The statement of the form: ‘The results presented in this variations are centred on the monthly mean value, paper rely on the data collected at Port Stanley shown on the left side of the page. magnetic observatory, operated by the British Geological Survey.’ 4.3 Magnetograms The daily magnetograms are plotted using one- Commercial users can contact the geomagnetism minute values of D, H and Z from the fluxgate team for information on the range of applications sensors, with any gaps filled using back-up data. The and services offered. Full contact details are magnetograms are plotted to a variable scale; scale available at www.geomag.bgs.ac.uk/contactus/staff bars are shown to the right of each plot. The absolute level (the monthly mean value) is indicated on the left side of the plots.
© NERC 2020. All rights reserved Edinburgh British Geological Survey 2020
PORT STANLEY OBSERVATORY
ABSOLUTE OBSERVATIONS
Declination Inclination Total Field Horizontal Intensity Vertical Intensity Site Absolute Day Time Absolute Baseline Time Absolute Absolute Baseline Absolute Baseline Date difference corrected Observer Number (UT) (º) (º) (UT) (º) (nT) (nT) (nT) (nT) (nT) (nT) 11-Jan-20 11 20:03 2.6420 2.9467 20:09 -50.1287 -9.7 28126.7 18031.0 18116.3 -21586.9 -21670.7 NB 11-Jan-20 11 20:15 2.6292 2.9433 20:22 -50.1308 -9.7 28126.4 18030.1 18115.9 -21587.3 -21671.0 NB 25-Jan-20 25 16:16 2.6830 2.9450 16:22 -50.1313 -9.7 28128.8 18031.4 18113.9 -21589.3 -21672.1 NB 25-Jan-20 25 16:28 2.6834 2.9417 16:34 -50.1333 -9.7 28127.8 18030.0 18113.7 -21589.2 -21672.3 NB
Port Stanley 2020 Declination : Absolute - Variometer (markers) and Baseline Applied (line)
2.95 5min
Horizontal Intensity : Absolute - Variometer (markers) and Baseline Applied (line)
18114 20nT
Vertical Intensity : Absolute - Variometer (markers) and Baseline Applied (line)
-21672 20nT
Total Intensity : Absolute (Proton F) - Baseline Adjusted Variometer (derived F)
9.7 20nT
Temperature Inside Variometer Hut
22.7 20 C
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Falkland Islands January 2020 1 2 3 4
o D 2.62 0.50
H 18026
Z -21594
5 6 7 8
D 2.62
H 18026 150 nT
Z -21594
9 10 11 12
D 2.62
H 18026
Z -21594 150 nT
13 14 15 16
D 2.62
H 18026
Z -21594
6 12 18 24 6 12 18 24 6 12 18 24 6 12 18 24 17 18 19 20
o D 2.62 0.50
H 18026
Z -21594
21 22 23 24
D 2.62
H 18026 150 nT
Z -21594
25 26 27 28
D 2.62
H 18026
Z -21594 150 nT
29 30 31 6 12 18 24 UT D 2.62
H 18026
Z -21594
6 12 18 24 6 12 18 24 6 12 18 24 Falkland Islands January 2020 Date: 01-01-2020Falkland Islands Day number: 001 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 20nT
Vertical Intensity in nT
-21594 20nT
0 3 6 9 12 15 18 21 24
Date: 02-01-2020 Day number: 002 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 20nT
Vertical Intensity in nT
-21594 20nT
0 3 6 9 12 15 18 21 24 Hour (UT) Date: 03-01-2020Falkland Islands Day number: 003 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 30nT
Vertical Intensity in nT
-21594 20nT
0 3 6 9 12 15 18 21 24
Date: 04-01-2020 Day number: 004 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 30nT
Vertical Intensity in nT
-21594 20nT
0 3 6 9 12 15 18 21 24 Hour (UT) Date: 05-01-2020Falkland Islands Day number: 005 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 40nT
Vertical Intensity in nT
-21594 30nT
0 3 6 9 12 15 18 21 24
Date: 06-01-2020 Day number: 006 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 20nT
Vertical Intensity in nT
-21594 10nT
0 3 6 9 12 15 18 21 24 Hour (UT) Date: 07-01-2020Falkland Islands Day number: 007 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 20nT
Vertical Intensity in nT
-21594 10nT
0 3 6 9 12 15 18 21 24
Date: 08-01-2020 Day number: 008 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 30nT
Vertical Intensity in nT
-21594 20nT
0 3 6 9 12 15 18 21 24 Hour (UT) Date: 09-01-2020Falkland Islands Day number: 009 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 20nT
Vertical Intensity in nT
-21594 10nT
0 3 6 9 12 15 18 21 24
Date: 10-01-2020 Day number: 010 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 20nT
Vertical Intensity in nT
-21594 20nT
0 3 6 9 12 15 18 21 24 Hour (UT) Date: 11-01-2020Falkland Islands Day number: 011 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 10nT
Vertical Intensity in nT
-21594 10nT
0 3 6 9 12 15 18 21 24
Date: 12-01-2020 Day number: 012 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 20nT
Vertical Intensity in nT
-21594 20nT
0 3 6 9 12 15 18 21 24 Hour (UT) Date: 13-01-2020Falkland Islands Day number: 013 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 10nT
Vertical Intensity in nT
-21594 10nT
0 3 6 9 12 15 18 21 24
Date: 14-01-2020 Day number: 014 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 10nT
Vertical Intensity in nT
-21594 10nT
0 3 6 9 12 15 18 21 24 Hour (UT) Date: 15-01-2020Falkland Islands Day number: 015 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 10nT
Vertical Intensity in nT
-21594 10nT
0 3 6 9 12 15 18 21 24
Date: 16-01-2020 Day number: 016 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 20nT
Vertical Intensity in nT
-21594 10nT
0 3 6 9 12 15 18 21 24 Hour (UT) Date: 17-01-2020Falkland Islands Day number: 017 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 20nT
Vertical Intensity in nT
-21594 20nT
0 3 6 9 12 15 18 21 24
Date: 18-01-2020 Day number: 018 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 20nT
Vertical Intensity in nT
-21594 10nT
0 3 6 9 12 15 18 21 24 Hour (UT) Date: 19-01-2020Falkland Islands Day number: 019 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 10nT
Vertical Intensity in nT
-21594 10nT
0 3 6 9 12 15 18 21 24
Date: 20-01-2020 Day number: 020 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 10nT
Vertical Intensity in nT
-21594 10nT
0 3 6 9 12 15 18 21 24 Hour (UT) Date: 21-01-2020Falkland Islands Day number: 021 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 20nT
Vertical Intensity in nT
-21594 20nT
0 3 6 9 12 15 18 21 24
Date: 22-01-2020 Day number: 022 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 20nT
Vertical Intensity in nT
-21594 10nT
0 3 6 9 12 15 18 21 24 Hour (UT) Date: 23-01-2020Falkland Islands Day number: 023 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 20nT
Vertical Intensity in nT
-21594 10nT
0 3 6 9 12 15 18 21 24
Date: 24-01-2020 Day number: 024 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 20nT
Vertical Intensity in nT
-21594 10nT
0 3 6 9 12 15 18 21 24 Hour (UT) Date: 25-01-2020Falkland Islands Day number: 025 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 10nT
Vertical Intensity in nT
-21594 10nT
0 3 6 9 12 15 18 21 24
Date: 26-01-2020 Day number: 026 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 30nT
Vertical Intensity in nT
-21594 20nT
0 3 6 9 12 15 18 21 24 Hour (UT) Date: 27-01-2020Falkland Islands Day number: 027 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 10nT
Vertical Intensity in nT
-21594 10nT
0 3 6 9 12 15 18 21 24
Date: 28-01-2020 Day number: 028 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 20nT
Vertical Intensity in nT
-21594 20nT
0 3 6 9 12 15 18 21 24 Hour (UT) Date: 29-01-2020Falkland Islands Day number: 029 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 20nT
Vertical Intensity in nT
-21594 20nT
0 3 6 9 12 15 18 21 24
Date: 30-01-2020 Day number: 030 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 30nT
Vertical Intensity in nT
-21594 10nT
0 3 6 9 12 15 18 21 24 Hour (UT) Date: 31-01-2020Falkland Islands Day number: 031 Declination in degrees east
2.62 15min
Horizontal Intensity in nT
18026 20nT
Vertical Intensity in nT
-21594 20nT
0 3 6 9 12 15 18 21 24 Falkland Islands Observatory: Declination (degrees)
2.81 Rotn
2.51 2530 Feb19
2531 Mar
2532 Apr
2533 May
2534 Jun
2535 Jul
2536
2537 Aug
2538 Sep
2539 Oct
2540 Nov
2541 Dec
2542 Jan20
2543
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 Hourly Mean Values Plotted By Bartels Solar Rotation Number Falkland Islands Observatory: Horizontal Intensity (nT)
18114 Rotn
17982 2530 Feb19
2531 Mar
2532 Apr
2533 May
2534 Jun
2535 Jul
2536
2537 Aug
2538 Sep
2539 Oct
2540 Nov
2541 Dec
2542 Jan20
2543
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 Hourly Mean Values Plotted By Bartels Solar Rotation Number Falkland Islands Observatory: Vertical Intensity (nT)
-21575 Rotn
-21637 2530 Feb19
2531 Mar
2532 Apr
2533 May
2534 Jun
2535 Jul
2536
2537 Aug
2538 Sep
2539 Oct
2540 Nov
2541 Dec
2542 Jan20
2543
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 Hourly Mean Values Plotted By Bartels Solar Rotation Number Falklands Is Observatory 2020 Daily Mean Declination (deg)
2.62 10min
Daily Mean Horizontal Intensity (nT)
18026 50nT
Daily Mean Vertical Intensity (nT)
-21594 50nT
Daily Mean Total Intensity (nT)
28128 50nT
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Monthly Mean Values for Port Stanley Observatory 2020
Month D H I X Y Z F
January 2° 37.4´ 18026 nT -50° 08.8´ 18007 nT 825 nT -21594 nT 28128 nT
Note i. The values shown here are provisional.