UPDATED INFORMATION ON*

SPAIN’s

ANTARCTIC and sub-ANTARCTIC “WEATHER-FORECASTING” INTERESTS

for

The International Antarctic Weather Forecasting Handbook:

IPY 2007-08 Supplement

by

Antonio Labajo Salazar

Subdirector General de Climatología y Aplicaciones

Agencia Estatal de Meteorología

Leonardo Prieto Castro 8. 28040 MADRID

E-mail: alabajo@inm.es

Submitted March 2008

*Contributions for:

            Section 7.3.N Livingston Island, South Shetland Island

            Section 7.3.4 Deception Island, South Shetland Island.

Editors’ note: the information regarding Livingston Island constitutes a new section – the Editors may need to consider the need to renumber sections.

7.3.N               Livingston Island, South Shetland Islands

Editors’ note – may need a new section number as detailed information regarding Livingston Island was not included in the original handbook.

7.3.N.1           Topography and local environment

Livingston Island is located in the South Shetland Islands at the tip of the Antarctic Peninsula (Figure 7.3.N.1.1 (Spain-updated)). It is the second island in extension and has dimensions of about 73 km by 34 km. Most of the island is covered by ice but bare, rocky peaks protrude at various places and the West side of Byers Peninsula and some places near the coast are free of ice along the summer. East is very mountainous with the height maximum in Friesland Mount, 1770 m. The coast is deeply cut by many sheltered fjords, bays and peninsulas such as South Bay, Siddons Point, Willians Point or Byers Peninsula.

The island axis is WSW to ENE and the two open stations along the summer, Juan Carlos I and St. Kliment Ohridiski, are located in South Bay. The Spanish Juan Carlos I Antarctic Base was open in 1988 and, actually, has an AWS all the year. It is situated at 100 m of de coast on the ice free ground. The staff is about 20 people. The Bulgarian St. Kliment Ohridiski Base was open in 1993. It is located at 100 m of de coast on the ice free ground.

Figure 7.3.N.1.1 (Spain-updated). A map of Livingston Island

7.3.N.2           Operational requirements and activities relevant to the forecasting process

At the time of writing the following summer–only stations were in use on the island:

            Juan Carlos I (Spain) (62° 39´ 46″ S, 60° 23´ 20″ W, 12 m AMSL).

            St. Kliment Ohridiski (Bulgaria) (62°38′29″S, 60°21′53″W)

There is one summer camp in Byers Peninsula in order to carry out biological research. In this area there is one operative AWS all year.

7.3.N.3           Data sources and services provided

Juan Carlos I. There is a meteorology and climatology data program along the summer since 1988. Since 1997 there are meteorological data all year, although the record is not complete, and at present there is one AWS.

When the Base is open the routine weather observations are sent internationally every six hours through the GTS via METEOSAT. Special forecasts to support the investigation groups and logistics activities in Livingston Island and Deception Island are regularly made. Maritime forecast are also made for the Spanish ships in this area. Occasionally, aeronautic forecasts are required to some helicopters.

Forecasts are made using daily information from National Meteorological Institute of Spain and ECMWF products:

♦        Forecasts to D, D+1, D+2 y D+3 to Gabriel de Castilla (Deception Island) and Juan Carlos I (Livingston Island )

♦        Maritime forecasts to D, D+1, D+2 y D+3 to the Spanish ships in the area Bradsfield Strait and Drake Passage, depending the position and activity.

♦        Locals and specials forecasts to the different scientific Spanish projects on Livingston Island in glacier, mountain or South Bay.

7.3.N.4           Important weather phenomena & forecasting techniques

General overview

The climate conditions are similar to those found on King George Island. The island is located in one of the northernmost parts of the Antarctic and has a relatively mild, maritime climate. It is also located at the latitude of the circumpolar trough and is affected by many active depressions that pass through the Drake Passage, bringing frequent gales and precipitation. The weather can generally be described as unsettled and gloomy weather with low stratus and strato–cumulus prevails. Precipitation is frequent and in the form of snow, rain, or drizzle. Cyclonic eddies move into this area on both zonal and meridian trajectories. The zonal systems are frequently fast–moving from west to east with speeds exceeding 28 m s–1 (~55 kt).

Liquid precipitation events are often associated with these north-westerly fronts.  Coming from the northwest bring warmer and moister air toward the island and some time have had strong precipitation with 50 mm/24 h.

In the summer, Byers Peninsula and little areas near the sea are with ice ash while in the winter the ground is mostly snow–cove red.

Surface wind and the pressure field

The direction of the surface wind on Livingston Island is predominately either NNE (summer) or SSW (rest of year) (Table 7.3.N.4.1 (Spain-updated), Table 7.3.N.4.2 (Spain-updated), Figure 7.3.N.4.1 (Spain-updated), and Figure 7.3.N.4.2 (Spain-updated). It is possible the influence of the Bay South and the mountains, with your axis from SW-NW, on the wind direction, but this wind rose is similar in the AWS of Byers Peninsula. The high frequency of major depressions passing close to the area means that the winds are rather variable on a day–to–day basis and gales are frequent. The area is affected by the semi–annual oscillation and surface pressures are lowest (highest) in the spring/autumn (winter and summer)

Upper wind, temperature and humidity

No radiosonde data are available for the region but upper–air conditions can be predicted using numerical weather prediction model output.

Clouds

Low stratiform clouds with heights around 300–600 m (~1,000–2,000 ft) are quite common at this location and are normally associated with synoptic scale weather systems approaching from the west. Orographic clouds are commonly observed.

Visibility: blowing snow and fog

No specific information on forecasting has been obtained.

Surface contrast including white–out

Surface contrast is usually good during the summer when the ground is clear of snow.

Horizontal definition

Not relevant on the islands as there are no flying activities.

Precipitation

Precipitation is a frequent meteor on the islands due to the many depressions crossing the area. It can be predicted using model rain/snowfall fields if available or from the model ECMWF fields. In addition, satellite imagery can provide useful information on small synoptic or mesoscale systems that may bring precipitation. In winter, most of the precipitation falls as snow, although rain can fall at any time of the year. In summer rain or snow can fall. The amount can be very variable from year to year; monthly totals during the summer in excess of 100 mm are common (Table 7.3.N.4.1 (Spain-updated)).

Temperature and chill factor

At Juan Carlos I the annual mean temperature is usually in the range –1 to –3oC with temperatures falling to a minimum of around –22ºC during the winter. In summer the mean temperature is one or two degrees above freezing, falling to several degrees or more before freezing in winter. During the winter the temperatures are particularly variable (Table 7.3.N.4.1 (Spain-updated)).

Icing

No specific information on forecasting has been obtained.

Turbulence

No specific information on forecasting has been obtained.

Hydraulic jumps

These are not reported on the islands.

Sea ice

No specific information on forecasting has been obtained.

Wind waves and swell

No specific information on forecasting has been obtained.

Table 7.3.N.4.1 (Spain-updated). Climate statistics for Juan Carlos I Station (62° 39´ 46″ S, 60° 23´ 20″ W, 12 m AMSL), Livingston Island. (Compiled from data spanning 1988–2007 for INM )

Element/month

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sept

Oct

Nov

Dec

Year

Nº month used

18

20

11

10

10

9

10

9

9

9

6

17

  

Mean daily temperatures (ºC)

2,6

2,3

1,3

-0,3

-1,5

-3,8

-4,6

-4,4

-3,4

-2,3

0,3

1,4

-1,0

Highest daily maximum temp. (ºC)

15,5

11,0

9,4

8,7

5,5

5,9

5,0

6,9

10,8

10,6

10,2

15,0

15,5

Lowest daily minimum temp. (ºC)

-3,2

-4,7

-10,9

-10,7

-12,8

-18,0

-22,4

-18,9

-16,9

-15,0

-8,9

-7,0

-22,4

Mean relative humidity (%)

81

83

80

82

82

82

83

83

84

78

80

79

81,4

Mean wind direction

NNE

NNE

NNE

SSW

SSW

SSW

SSW

SSW

SSW

SSW

SSW

NNE

SSW

Mean wind speed (ms-1)

3,2

3,3

3,7

3,6

3,7

4,0

4,0

4,0

3,8

3,9

3,5

3,3

3,7

Maximum wind gust - (ms-1)

27,7

38,4

41,5

38,9

32,4

38,2

30,7

37,8

32,4

37,2

26,9

38,2

41,5

Nº day of gales

2

3

6

7

7

7

7

9

6

3

5

3

64

Mean MSL pressure (hPa)

988,9

990,9

991,4

988,3

993,6

993,7

995,5

991,6

992,1

992,3

988,7

988,7

991,3

Mean-monthly precip. (mm)

44,8

58,5

47,3

43,0

29,3

10,1

4,0

7,7

17,6

45,3

30,8

38,8

31,4

Nº of rain days

16

17

15

16

11

6

4

6

12

17

13

15

148

Table 7.3.N.4.2 (Spain-updated) Mean–monthly distribution (%) of wind directions at Juan Carlos I Station (62° 39´ 46″ S, 60° 23´ 20″ W, 12 m AMSL), Livingston Island. (Compiled from data spanning 1988–2007 for INM).

Direction/Month

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sept

Oct

Nov

Dec

N

8,8

7,8

7,1

4,9

6,2

6,3

8,2

5,6

9,6

9,3

7,6

8,7

NNE

14,0

11,8

11,8

9,2

8,6

10,4

11,6

7,6

11,1

10,6

9,3

13,7

NE

9,0

9,1

8,3

7,8

6,2

5,8

7,0

5,2

7,4

5,1

5,4

7,4

ENE

6,0

6,1

7,6

8,3

5,4

7,1

6,5

5,4

6,2

5,5

6,6

6,2

E

2,6

2,8

3,2

5,5

4,5

7,8

7,0

6,1

5,1

4,0

3,3

2,7

ESE

2,7

3,2

4,3

5,6

4,8

6,6

4,5

5,1

3,4

2,2

3,2

2,9

SE

1,4

2,0

2,0

2,1

2,6

2,7

2,0

1,9

2,2

2,2

1,6

1,6

SSE

2,7

4,0

3,6

4,1

5,8

7,4

3,9

4,7

3,7

5,4

4,3

2,6

S

4,9

6,6

8,5

7,9

9,9

10,3

4,6

6,4

7,8

8,8

6,0

5,7

SSW

11,0

11,4

11,4

14,6

14,9

14,9

16,5

20,0

15,0

16,2

22,6

11,6

SW

4,8

4,9

3,7

4,5

4,7

3,7

4,7

6,2

4,9

4,8

7,0

6,3

WSW

4,8

3,8

2,4

1,4

1,6

1,1

1,8

2,5

2,2

3,2

4,0

5,7

W

5,9

4,6

4,2

3,3

3,8

2,4

3,3

4,9

2,9

3,2

4,4

5,0

WNW

5,9

6,8

6,2

6,5

7,0

2,6

4,6

4,3

3,2

4,2

4,8

5,5

NW

3,9

3,7

4,0

3,1

3,0

2,3

3,1

2,7

2,3

4,6

3,1

3,4

NNW

5,9

5,0

5,9

3,6

3,7

3,7

5,7

6,0

5,2

5,6

3,7

6,1

Calm

5,4

6,7

5,6

7,6

7,2

5,0

5,0

5,5

7,9

5,3

3,2

4,9

                          Figure 7.3.N.4.1 (Spain-updated). Annual mean wind

                          Direction at Juan Carlos I Station

                          (62° 39´ 46″ S, 60° 23´ 20″ W, 12 m AMSL).

                        (Compiled from data spanning 1988–2007 for INM ).

                           Figure 7.3.N.4.2 (Spain-updated). Annual mean wind

                           speed v/s direction at Juan Carlos I Station

                           (62° 39´ 46″ S, 60° 23´ 20″ W, 12 m AMSL).

                            (Compiled from data spanning 1988–2007 for INM )

7.3.4               Deception Island, South Shetland Islands

7.3.4.1            Topography and local environment

Editors’ note: may need to amend original wrt number of stations.

7.3.4.2            Operational requirements and activities relevant to the forecasting process

Summer–only stations:

There are two stations:

Gabriel de Castilla (Spain) (62º59’S, 60º41’W, 15 m AMSL)

Deception (Argentina) (62º 59´ S, 60º 34´ W, 7 m AMSL)

7.3.4.3            Data sources and services provided

Gabriel de Castilla. There is a Meteorology and Climatology data program over summer since 2005, with data collected all year, although the record is not complete, and at present there is only one AWS (in operation all the year).

With daily information from National Meteorological Institute of Spain and ECMWF products every day the forecasts to D, D+1, D+2 y D+3 are made from Juan Carlos I.

7.3.4.4            Important weather phenomena & forecasting techniques

General overview

Editors’ note: no new specific information provided.

Surface wind and the pressure field

Editors’ note: no new specific information provided.

Upper wind, temperature and humidity

Editors’ note: no new specific information provided.

Clouds

Editors’ note: no new specific information provided.

Visibility: blowing snow and fog

Editors’ note: no new specific information provided.

Surface contrast including white–out

Editors’ note: no new specific information provided.

Horizontal definition

Editors’ note: no new specific information provided.

Precipitation

Editors’ note: no new specific information provided.

Temperature and chill factor

Editors’ note: no new specific information provided.

Icing

Editors’ note: no new specific information provided.

Turbulence

Editors’ note: no new specific information provided.

Hydraulic jumps

Editors’ note: no new specific information provided.

Sea ice

Editors’ note: no new specific information provided.

Wind waves and swell

Editors’ note: no new specific information provided.