METADATA FILE

August 3, 2005

**Name of Observatory** Grantley Adams Airport

**Country** Barbados

**WMO Index Number** 78954

**Latitude and Longitude** 13º04.820"North, 59º29.124W

(Measured by GPS Aug 2005)

**Altitude of Barometer Cistern** 184 feet above msl (measured)

**Altitude of Rain Gauge** 172 feet above msl (estimated)

**Date of This Entry** August 3, 2005

**Type of Observatory** Surface, Upper Air, Climatology

**Hours of Operation** 24

**Surface Observations** 24 hourlies and 8 Synoptic

**Upper Air Soundings Performed** 12Z daily plus 00Z during Hurricane
season

**Additional CLIMAT parameters observed** Evaporation and Sunshine

**Description of land and activities within 10 kilometers of
observatory**

The Observatory is located at Grantley Adams International Airport which
is in the southeast quadrant of the island. The observatory is roughly 1
½ miles northwest of the shoreline. The runway is oriented East-West and
is between the observatory and the ocean. The land surrounding the
airport is relatively flat with a few hills that are several kilometers
away and to the Northwest. Agriculture is the main activity surrounding
the observatory and is primarily sugar cane crops. The housing and
business activities are along the western shore and are at least 10
kilometers from the observatory. Of course there is considerable
shipping in the capital city of Bridgetown which is several miles NW.
The airport is fairly busy with several flights per day using island
hopping light aircraft as well as jumbo jets.

**Description of the Instrument Field**

The current instrument field is large in comparison to other
observatories. The field is grass covered, with ample spacing for all
the instruments and is enclosed by a 12 foot fence. The instrument field
was originally located near the old airport terminal which is about a
half mile from its present location. The instrument field was moved to
its present location in 1979. During January 2004, the airport
authorities at Grantley Adams constructed a huge aircraft hangar within
a few yards of the existing instrument field. This hangar houses the SST
Concorde Jet. The Director of the Barbados Meteorological Service was
not consulted about the location or design of this hangar and his
concerns were ignored. This hangar obstructs the entire northeast
quadrant of the observing field. All observed winds from 360 to 090
degrees are considered to be erroneous. Also there are several instances
when the accuracy of the collection of rainfall is questionable because
the hangar interrupts the flow of the wind causing "deadspots" over the
gauges. The IF is more or less surrounded by parking lots for equipment
and automobiles. The parking pavement begins just a few feet from the IF
fence. It is difficult to say whether the parking and other activities
effect the temperature measurements.

**INSTRUMENT DESCRIPTIONS**

The Instrument Shelter is similar to the standard Simpson Shelter and is
made of white wooden louvered slats. The shelter is approximately 2 feet
wide, 14 inches deep, and 14 inches high. The floor of the shelter is
roughly 5 feet above a cement pad and is facing North.

The official Psychrometer, Maximum and Minimum Thermometers are properly
mounted within the Instrument Shelter. The Psychrometer is standard
Casella liquid in glass thermometers with a muslim wick permanently
bathed distilled water. The Psychrometer is not artificially aspirated.
The Casella Maximum and Minimum thermometers are properly mounted in a
horizontal plane above the Psychrometer The thermometers were compared
with the handheld Lufft E200 Stand V1 high precision thermometer. The
differences were usually less than two tenths of a degree and were
dictated more by the error of parallax. The Contractor is satisfied that
the observatory is making accurate temperature and humidity
measurements.

The rain gauge is a standard metal collecting instrument sitting on the
ground with the orifice approximately 12 inches above the ground. The
orifice is 5 inches in diameter. The rain is funneled into a glass
bottle for manual measurement. The gauge is manufactured by Perkins of
the UK.

The official wind system is part of a Casella Automatic Weather Station
(s/n M103159) is mounted on a 10 meter mast and roughly 1 kilometer east
of the existing instrument field.

A standard size evaporation pan with a wind counter is located centrally
in the IF.

There is a Campbell-Stokes sunshine recorder that is properly exposed
and the recording cardboard collars are accurately positioned.

The official barometer is a Negretta Precision Barometer Mark II ref.
Met20005, s/n 8483/83 located in the observers office. The barometer is
166 feet above sea level while The airport runway ranges between 152 and
159 feet above sea level.

**CAUTIONS TO THE USER OF THIS DATA**

The official records for the old instrument field date back to 1942.
Some of the records were lost during a hurricane in 1955. Users of these
records should note that during 1971-1972 the instruments were
temporarily placed on the roof of a building which resulted in spurious
temperature readings. The instruments were removed from the roof and put
back in their original location near the old terminal.

:Currently (2005), the airport is undergoing major renovation and
expansion which is causing the authorities to once again move the
instrument field. The new instrument field will be 1 kilometer due east
of the existing field and at nearly the same height above sea level. The
contractor used GPS to measure the location of the center of the field
to be 13º 04.896 North and 59º28.588 West. The new site is 100 square
feet in area, grass covered and is near the east end of the runway and
roughly one half mile from the ocean. The authorities have indicated
that this area will not be developed and the surrounding area will be
kept free of buildings, traffic, and pavement. The Director of the
Meteorololgical Service installed the Casella Automatic Weather station
in this new location in early 2005 to begin comparison readings in
anticipation of the move. The instruments are part of the basic Casella
station identified above and properly mounted. While the airport
authorities have indicated a move will occur during 2005 or 2006 the
Met. Department does not think this will happen for a few years.

**Photographs**

The contractor has included photographs of the existing IF, the proposed
new IF and the Upper Air Station which is on the other side of the
runway and roughly 1 ½ miles to the southwest.