The island receives an average of 2623 mm of rain per year. Day-time temperatures reach an average of 32°C, with night-time lows of approximately 23°C. The meteorological year is divided into two parts: a pronounced dry season (approximately from mid-December to the end of April), and a wet season (May to mid-December). On average, only 285 mm of rain falls during the dry season. Relative humidity, soil moisture, air pressure, solar radiation, evapotranspiration, wind speed and direction all show marked wet/dry season differences. On the other hand, temperature varies relatively little throughout the year.

There are three Physical Monitoring Stations on BCI: The Clearing (‘El Claro’), the Lutz Watershed Weir, the Lutz Tower and the Conrad Weir.

Data are collected using two different methods: electro-mechanical (electronic sensors, data loggers, chart recorders, etc.), and manual (rain gauges, max-min thermometers, sling psychrometers, soil samples, etc.) by a technician. In general, manual measurements have shown themselves to be the most accurate over the long-term. Wherever possible, parameters are measured both manually and electronically. The only exceptions to this rule are solar radiation (electronic only), estimated evapotranspiration (manual only), and gravimetric soil moisture (manual only).

For a summary of the most recent data collected, plus long-term averages report, please click on the following link:
Yearly_Reports_Barro_Colorado_Island
Monthly summaries_BCI_horizontal
Monthly summaries_BCI_vertical


Special El Niño 2015/6 analysis: 2015_16 El Niño Analysis.xlsx

The Clearing (or ‘El Claro’ as it is know on the island) is a small grass-covered clearing located between the edge of the forest and the foundations of several former laboratory buildings. The station was established in 1972 and was the original meteorological station managed by STRI. An older station (established in 1929 and operated by the Panama Canal Authority) is located near to the shore of Lake Gatun.

The Clearing station records both manual and electronic (tipping bucket) precipitation, manual and electronic temperature and humidity, electronic barometric pressure, as well as manual potential evapotranspiration (EtGage atmometer).

Sensor manuals in .pdf format are available for download here.

Parameters	Sensor Model	Type	Manual	Methods
Barometric Pressure	CS106-PTB110	Electronic	cs106.pdf
Evapotranspiration	ET-Gauge	Manual	3710ETGauge.pdf	Methods_Manual_Potential_Evapotranspiration.pdf
Temperature & RH	Viasala hmp45c (discontinued) Campbell Sci. CS215	Electronic	hmp45c.pdf cs215.pdf	Methods_Electronic_Air_Humidity.pdf
Temperature, daily Max	Novalynx 210-4411 Standard Thermometer	Manual	Thermometer_Novalynx_MaxMin.pdf
Temperature, daily Min	Novalynx 210-4411 Standard Thermometer	Manual	Thermometer_Novalynx_MaxMin.pdf
Temperature, Daily Max/Min	Taylor Model 5458 Min/Max Thermometer	Manual	Thermometer_Taylor_MaxMin_5458.pdf
Rainfall	Campbell Sci. TB4 tipping bucket	Electronic	tb4.pdf
Rainfall	Novalynx rain gauge	Manual	Rain_gauge_Novalynx_Model_260-2510.pdf Rain_gauge_Novalynx_Model_260-2520.pdf	Methods_Manual_Precipitation.pdf
Relative humidity from wet/dry bulb temperature	BACHARACH Sling Psychrometer	Manual	Bacharach_Sling_Psychrometer1.pdf Bacharach_Sling_Psychrometer2.pdf	Methods_Manual_Relative_Humidity.pdf

Parameters	Frequency	Units	Downloads
Air Temperature (max, min, average)	15 min	Celsius	Barro Colorado Island, Clearing_Air Temperature
Barometric Pressure (average)	15 min	mmHg	Barro Colorado Island, Clearing_Air Pressure
Rain (total)	5 min	mm	Barro Colorado Island, Clearing_Precipitation
Relative Humidity (max, min, average)	15 min	%	Barro Colorado Island, Clearing_Relative Humidity

Parameters	Frequency	Units	Downloads
Rain (daily total)	daily	mm	Barro Colorado Island, Clearing_Precipitation, manual
Temperature, Daily Max/Min	daily	Celsius	Barro Colorado Island, Clearing_Air Temperature, manual
Evapotranspiration	daily	cm	Barro Colorado Island, Clearing_Potential Evaporation
Relative Humidity Sling Psychrometer	daily	%	Barro Colorado Island, Clearing_Relative Humidity, manual

Metadata_BCI.txt

The Lutz catchment is probably typical of the many small, steeply-sloped catchments draining away from the center of the island. It is located immediately east of the laboratory clearing. The steeply sloped (20-30°) catchment drains an area of 9.73 ha. The forest covering the catchment was mostly deforested during the construction of the Panama Canal around the turn of the century, but since then it has been allowed to regenerate.

Built in 1972, the Lutz tower was originally 42m in height. In October of 2001 the tower was raised to 48m due to the increase in height of the surrounding forest that happened during the previous 30 years.

The station consists of a vertical meteorological transect through the forest canopy with temperature/humidity sensors at 1, 20, 42 and 48m. . There are solar radiation sensors, an anemometer and an EtGage atmometer on the uppermost level of the tower. Manual measurements of max/min temperature and noon-time relative humidity are taken at the Lutz tower as well.

Gravimetric soil moisture samples are made at ten locations around the Lutz catchment. Soil samples are made at 0-10cm and 30-40cm at each location. Samples are taken every two weeks during the period June to November and weekly from December to May.

The V-notch weir located near the base of the tower measures the run-off from most of the Lutz creek catchment. Data are recorded using both a chart recorder and a pressure-base bubbler. Daily height recordings are made by a technician for calibration purposes.

Sensor manuals in .pdf format are available for download here.

Parameters	Sensor Model	Type	Manual	Methods
Evapotranspiration	ET-Gauge	Manual	3710ETGauge.pdf	Methods_Manual_Potential_Evapotranspiration.pdf
Gravimetric Soil Moisture	n/a	Manual		Methods_Manual_Soil_moisture.pdf
Relative humidity from wet/dry bulb temperature	BACHARACH Sling Psychrometer	Manual	Bacharach_Sling_Psychrometer1.pdf Bacharach_Sling_Psychrometer2.pdf	Methods_Manual_Relative_Humidity.pdf
Run-off	ISCO 3230 Bubbler Flow Meter	Electronic	ISCO3230Bubbler.pdf	Methods_Lutz_weir_runoff.pdf
Solar Radiation	LiCor LI200X pyranometer	Electronic	li200x.pdf	Methods_Electronic_Solar_Radiation.pdf
Temperature & RH	Viasala hmp45c (discontinued) CAMPBELL SCI. CS700 TIPPING BUCKET	Electronic	hmp45c.pdf cs215.pdf	Methods_Electronic_Air_Humidity.pdf
Temperature, daily Max/Min	Novalynx 210-4411 Standard Thermometer	Manual	Thermometer_Novalynx_MaxMin.pdf
Temperature, daily Min/Max	Taylor Model 5458 Min/Max Thermometer	Manual	Thermometer_Taylor_MaxMin_5458.pdf
Wind speed & direction	Young Wind Monitor AQ	Electronic	Young Wind Monitor AQ.pdf	Methods_Electronic_Wind_Speed_Dir.pdf
Wind passage	Totalizing Anemometer NovaLynx Model200-2510	Manual	Totalizing_Anemometer_NovaLynx_Model200-2510.pdf	Methods_Manual_Wind_Passage.pdf

Parameters	Frequency	Units	Downloads
Air Temperature 1m (max, min, average)	15 min	Celsius	Barro Colorado Island, Lutz Tower 1m_Air Temperature
Air Temperature 20m (max, min, average)	15 min	Celsius	Barro Colorado Island, Lutz tower 20m_Air Temperature
Air Temperature 42m (max, min, average)	15 min	Celsius	Barro Colorado Island, Lutz tower 42m_Air Temperature
Air Temperature 48m (max, min, average)	15 min	Celsius	Barro Colorado Island, Lutz tower 48M_Air Temperature
Relative Humidity 1m (max, min, average)	15 min	%	Barro Colorado Island, Lutz tower 1m_Relative Humidity
Relative Humidity 20m (max, min, average)	15 min	%	Barro Colorado Island, Lutz tower 20m_Relative Humidity
Relative Humidity 42m (max, min, average)	15 min	%	Barro Colorado Island, Lutz tower 42m_Relative Humidity
Relative Humidity 48m (max, min, average)	15 min	%	Barro Colorado Island, Lutz tower 48m_Relative Humidity
Solar Radiation Flux (max, min, average)	15 min	w/m2	Barro Colorado Island, Lutz tower 48m_Solar Radiation, Pyranometer
Wind Direction 45m (vect mean, std. deviation)	15 min	degrees	Barro Colorado Island, Lutz tower 42m_Wind direction
Wind Direction 48m (vect mean, std. deviation)	15 min	degrees	Barro Colorado Island, Lutz tower 48m_Wind direction
Wind Speed 42m (max, min, mean horiz speed)	15 min	km/hr	Barro Colorado Island, Lutz tower 42m_Wind speed
Wind Speed 48m (max, min, mean horiz speed)	15 min	km/hr	Barro Colorado Island, Lutz tower 48m_Wind Speed
Runoff Lutz Creek (level, flow-rate, discharge)	5 min	m3	Barro Colorado Island, Lutz Catchment_Runoff

Parameters	Frequency	Units	Downloads
Temperature 1m (Daily Max/Min)	daily	Celsius	Barro Colorado Island, Lutz tower 1m_Air temperature, manual
Temperature 42m (Daily Max/Min)	daily	Celsius	Barro Colorado Island, Lutz tower 42m_Air Temperature, manual
Temperature 48m (Daily Max/Min)	daily	Celsius	Barro Colorado Island, Lutz tower 48m_Air Temperature, manual
Evapotranspiration 42m	daily	cm	Barro Colorado Island, Lutz tower 42m_Potential Evaporation
Evapotranspiration 48m	daily	cm	Barro Colorado Island, Lutz tower 48m_Potential Evaporation
Relative Humidity 1m	daily	%	Barro Colorado Island, Lutz tower 1m_Relative Humidity, manual
Relative Humidity 20m	daily	%	Barro Colorado Island, Lutz tower 20m_Relative Humidity, manual
Relative Humidity 42m	daily	%	Barro Colorado Island, Lutz tower 42m_Relative Humidity, manual
Relative Humidity 48m	daily	%	Barro Colorado Island, Lutz tower 48m_Relative Humidity, manual
Soil Humidity – Lutz Creek H2O by wet, H2O by dry	1-2 weeks	%	Barro Colorado Island, Lutz catchment, Soil moisture, manual

The Conrad catchment is a more gently sloped catchment draining much of the central area of the island, including most of the 50-ha plot. The catchment is approximately 40.2 ha in size. Unlike the Lutz catchment, the forest covering the catchment was not cut during the construction of the Panama Canal.

The weir experienced several stages of development between 1993 and 1996 as additional height and wings were added to accommodate all stages of the Conrad stream. The weir consists of a 90 degree ‘V’ set into a two-stage rectangular weir. Data are recorded by a pressure-based bubbler.