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Misool Island
Home arrow Our Projects arrow Project #2
Project #2
Icone Precious Planet Weather Station 


Initial data collected allows the identification of very informative phenomena that are specific to the area.


Weather Station project completed

(Sensor installed on Batbitim)

(Weather Station)

(Photo E.B.)

Precious Planet financed the set up of the first weather station in the area in order to support a global approach to the ecosystem. This integrated station allows us to model, and monitor in real-time, all the basic elements of the local eco-system : atmospheric pressure, temperature, winds, pluviometry, currents and tides,…
The objective of this project is to provide support for all the Misool Conservation Centre’s aims.  This station will enable the creation of a global data base for future environmental surveys in the area.

Equipments financed by Precious Planet:
- The acquisition of a Davis semi-Pro integrated weather station (temperature, pluviometry, hygroscopy, anemometer, barometer, not of dew…) with PC connection and software
- Underwater sensors with connectors,
- A laptop for  the collection, analysis and storage of the data
- Set up and gauging of the instruments by an eco-volunteer (Ambroise).

Data is logged either automatically (batch) or by the Park Rangers (especially for marine sensors) and stored for analysis on a dedicated computer in the Misool Conservation Center.
Analysis reports are transmitted to Precious Planet on a regular basis and will be soon online on our website.

The collected data will also be transmitted to world scientific community through NOAA’s website www.noaa.gov

Indeed the station is generating data according to international scientific standards.  These new measurement points will help scientists improve their analytical models on global climate change.
The first analysis identifies very informative phenomena specific to the area : mixed tides out of “semidiurnal /uneven diurnal type” and “Barometric tides”.

Score board of the basic parameters of the area for January 2008
Parameter (unit)
Month average
Standard Deviation
Temperature (°C)
Wind speed (km/h)
Atmospheric pressure(hPa)
Parameter (unit)
Month accumulation
Rain rate / intensity mm/h)
Pluviometry (mm)

These results show an extremely stable weather conditions for January as is consistent with the season. This relative stability allows a simplified reading of the phenomenon of barometric tide.

Bringing to light of the barometric tides phenomenon

The diurnal oscillations of atmospheric pressure (or barometric tides) are rarely observed at temperate latitudes which are subject to frequent disruptions resulting of pressure changes of far greater amplitude.
By contrast, within sub-tropical areas, a relatively stable atmospheric pressure allows the detection of daily oscillations of low amplitude.
It deals with a complex phenomenon resulting for a large part to changes in air temperature and the position of the sun.
For the Misool area, the cycles are extremely regular, the high pressure occurs between 8 –10 AM and PM and the low pressure 3-5 AM and PM.
The average amplitude of the barometric tide is about 4hPa.
The barometric tides phenomenon is one of the trickiest issues of the tropical meteorology!
In our temperate latitudes, one just needs to check the global evolution of the barometer.  If pressures are high, we are in an anti-cyclonic situation, if the pressure are low, we are in a depression situation.  In tropical or sub-tropical areas, one must be able to interpret the variation of amplitude !
If the amplitude significantly decreases then a violent gale is expected within 12 to 36 h.

Measurements taken retrospectively by meteorologists show that in the case of a hurricane approach, barometric tides are almost “flat”.
However, precise a priori interpretation (hurricane forecasts) of the variations in amplitude of the barometric tides is still very difficult for scientists.
Thus we can see a afterwards that the area Misool has not been subjected to violent weather phenomena over the period (wind max. speed : 46.7 km/h). The barometric tides having maintained an extremely regular amplitude.

Bringing to light of the phenomenon of semidiurnal /uneven diurnal tides type
Every 24 hours there are 2 tide cycles (semi-diurnal) , but the cycles are uneven with very different amplitudes. This tide type is specific to the Asia Pacific area.
The uneven cycles result from the superposition of the diurnal tide to the semi-diurnal one, the tides are function of the moon position between the tropic and the equator.

For the Misool area, the inter-tidal average height is about 1.5 m for the “high” cycles and about 0.5 m for the “low” cycles.
Moreover, the tide cycle (whatever it is) complies with the well known sailors rules; the “twelth rule”; the tide rises/falls out of 1/12 of the inter-tidal height during the first hour, out 2/12 during the second one, out of 3/12 during the third one, out of 3/12 during the fourth one, out of 2/12 during the fifth one and out of 1/12 out the sixth one.
Indeed, « tidal waves » show the same features all around the world !