AB-C[sitecode].[year][A or B]

where the site codes are:

A and B correspond the first and second half of the year.

Each line of the files contains the following data

Site Code
Year
Day number
Time GMT
Incoming solar radiation (direct + diffuse)	(W /m^2)
Reflected solar radiation	(W /m^2)
Net all-wave radiation	(W /m^2)
Wet bulb temperature	(Degrees C)
Air temperature	(Degrees C)
Wind speed	(m/s)
Wind direction	(Degrees from North)
Soil heat flux	(W/m^2)
Rainfall	(mm)

The data were written to the files using the FORTRAN format statement -

FORMAT(1X,A2,1X,I4,1X,I3,1X,I4,1X,9(F9.2))

Missing data are given the value -99.99.

SITE DESCRIPTIONS

a. Reserva Ducke, Manaus

Reserva Ducke (2 57'S, 59 57'W) is an area of protected primary forest, 25 km north-east of Manaus at 80 m above mean sea level. The experimental site was also the site of the Amazon Regional Micrometeorological Experiment in the early 1980s (see Shuttleworth et al. (1991) for a summary), but was re-established for ABRACOS in late 1990. The mean forest canopy is 35 m high, but some trees reach up to 40 m. The forest in Reserva Ducke, in common with the other two forest sites studied, is made up of a large variety of tree species. The tallest species in the area around the tower are Piptadenia suaveolens Miq., Licania micrantha Miq., Bocoa viridiflora (Ducke) Cowan, Naucleopsis glabra Spruce ex Baill and Enterolobium schomburgkii Benth. The site is surrounded by undisturbed forest for at least 5 km. An extensive description of the site is given by Shuttleworth et al. (1984) and Roberts et al. (1990). The automatic weather station is mounted at the top of a 45 m aluminium tower.

b. Fazenda Dimona, Manaus

Pasture

Fazenda Dimona (2 19'S, 60 19'W) is a cattle ranch located about 100 km north of Manaus. The ranch is a 10 km square clearing at an altitude of 120 m above mean sea level. It was created in about 1975 by felling and burning an area of primary forest. The ground was planted with pasture grass (Brachiaria decumbens and Brachiaria humidicola) but 11% of the surface area is bare soil and many felled tree trunks still remain, covering 5% of the ground area (Wright et al. 1992). The pasture has been regularly burnt to destroy the vigorous regrowth of bushes. Since late 1992, however, this practice has ceased and the pasture is becoming rapidly overgrown. Instrumentation was installed at the site in September 1990. The automatic weather station is mounted at the surface. Descriptions of the site are given by McWilliam et al. (1993) and Wright et al. (1992) together with the results of biomass and micrometeorological measurements respectively.

Forest

Soil moisture access tubes where installed in primary forest close (900m) to the Pasture of Fazenda Dimona and the above site location details apply. See Hodnett et al. 1995.

c. Reserva Vale do Rio Doce, Maraba

This forest site (5 45'S, 49 10'W) was established in July 1991 in the forest reserve of the Companhia Vale do Rio Doce at 150 m above sea level 50 km to the south of Maraba. The forest reserve is 17,000 hectares in area and is to a large degree uncut, but is almost completely surrounded by cleared areas. The automatic weather station is mounted on top of a 52 m tower positioned to the east of a mature Brazil nut tree (Bertholletia excelsa HBK) with a height of 49 m, but the continuous forest canopy, consisting mainly of Inga alba (SW) Willd, Pourouma guianensis Aubl., Guarea guidonia (L.) Sleumer and Sagotia brachysepaia (Muell Arg.) R.Secco in the area surrounding the tower, is much lower, around 20 to 25 m. The abundance of the large Brazil nut trees is a characteristic feature of the forests in the Maraba region and means that the structure of the canopy in this area differs considerably from that of the Reserva Ducke or Reserva Jaru sites. See Roberts et al (1996), Sa et al (1996) and Solamao (1991).

d. Fazenda Boa Sorte, Maraba

Fazenda Boa Sorte (5 10'S, 48 45'W) is a cattle ranch 50 km to the north-east of Maraba at 170 m above mean sea level and was deforested sometime before 1975. The site was established in July 1991 and is a large area of pasture covered predominantly with tropical grass (Panicum maximum Jacq.) and small patches of bare soil: a red-yellow sandy loam Latosol (Oxisol). The ranchland has numerous Babau palms which, because of their resistance to fire, commonly remain after forest clearance, and as such is typical of clearings in the Maraba region. See Roberts et al (1996), Sa et al (1996). The site differs from Fazenda Dimona in that the dead tree trunks and stumps were removed in the initial clearance. The automatic weather station is mounted at the top of a 6 m aluminium tower.

e. Reserva Jaru, Ji-Parana

Reserva Jaru (10 05'S, 61 55'W) is a forest reserve owned by the Brazilian Environmental Protection Agency (IBAMA) and is located about 80 km north of Ji-Parana at 120 m above sea level. The 52 m forest tower was installed and instrumented in October 1991. The mean height of the forest canopy is 33 m. The tallest tree species in the area immediately surrounding the tower are Cedrella odorata, Inga sp., Dioclea cf bicolor Bth., Strychnos amazonicus Krukoff, Protium polybotrium and Leonia glycicarpa Ruiz, see McWilliam et al. (1996) and Roberts et al. (1996). The automatic weather station was mounted at the top of the tower.



f. Fazenda Nossa Senhora da Aparecida, Ji-Parana

This site (10 45'S, 62 22'W) was established in October 1991 on a cattle ranch 220 m above sea level about 50 km east-north-east of Ji-Parana . The site was deforested in about 1977 and is in the centre of an area of about 50 km in radius which has been largely cleared. The grass (Brachiaria brizantha) is clumpy and the original planting rows can still be clearly seen from above, see McWilliam et al. (1996) and Roberts et al. (1996). The area of bare soil was surveyed in April 1993 and found to form 12% of the surface area. The ranchland is similar in appearance to Fazenda Boa Sorte with several palms and, in contrast to Fazenda Dimona, with very few dead tree trunks. The pasture had been burnt in the month prior to equipment installation, but it was not burnt again during ABRACOS. The automatic weather station is mounted in a similar way to that at Fazenda Boa Sorte.

g. Manaus City

This urban weather station site was established in October 1990 close to the Intituto Nacional de Pesquisas da Amazonia (INPA) in Manaus (60 10'W, 3 6'S) to assess the effect of urbanisation on climate in Amazonia. The site is representative of the urban area of Manaus, but not in the centre of that area, see Maitelli and Wright (1996). The weather station was installed over an area of grass and so care should be taken with interpretation of data such as net radiation and reflected solar radiation. These parameters should not be assumed to be representative of the urban landscape as a whole. The weather station is mounted at the surface similarly to the Fazenda Dimona weather station.

For reasons of security and to avoid damage by livestock, the instruments at all the ranchland sites are located within wire fenced enclosures of about 10 m by 10 m. However, to ensure that the measurements are as representative as possible of the grazed areas, the grass within these enclosures is regularly monitored and cut when necessary to keep it of similar length to that outside the enclosures.

INSTRUMENTATION

The instruments used to record these data are discussed by Bastable et al.(1993) but are also summarised below. The data were recorded as hourly averages, or in the case of rainfall an hourly total, by a Campbell Scientific CR10 logger.

Solar radiation.

Kipp and Zonen (Delft, The Netherlands) CM-5 solarimeter recorded radiation of wavelengths 0.3 to 3 micrometers. A similar sensor but inverted was used to measure the reflected solar radiation. The error in these measurements is estimated to be about plus or minus 1 %.

Net radiation

Net all-wave radiation measured by a single dome Q*6 radiometer (Radiation Energy Balance Systems, Seattle, USA). A comparison was carried out between these instruments and the agreement between was found to be better than their probable calibration errors of about plus or minus 3%.

Wet bulb temperature and air temperature

The wet bulb and air temperatures were measured using aspirated platinum resistance thermometers housed in an Institute of Hydrology design psychrometer screen. The thermometers were calibrated against a standard and are accurate to plus or minus 0.1 degree C.

Wind speed and direction

Wind speed was measured by an DWR-201 anemometer and wind direction by a DWD-103 wind vane both manufactured by Didcot Instruments Ltd, Abingdon, UK. The anemometer has metal cups of robust design and a starting speed of 0.3 to 0.4 metres per second and a stalling speed of 0.2 metres per second.

Soil heat flux.

The soil heat flux was measured with two model 610 soil heat flux plates (Thornthwaite, Elmer, New Jersey, USA), which were installed at a depth of 5 mm. The value recorded in the dataset is an average of the values from the two instruments.

Rainfall

Rainfall was measured using a 0.2 mm resolution tipping bucket raingauge (Didcot Instrument Company, Abingdon UK). The instrument stood on a concrete slab at the surface. For the sites at which the weather station was mounted on a tower the raingauge was connected by a tube to a funnel mounted at the same height as the weather station.

START AND END DATES OF DATA

N.B The AWSs were not dismantled in December 1993 (excpet for Manaus City), and measurement continued beyond this date.These subsequent data are managed by CPTEC/INPE at Cachoeira Paulista, SP, Brazil.

MAJOR PERIODS OF MISSING DATA

Periods of more than 24 hours when data from all instruments is missing are listed. (click here to see)

Particular problems were experienced with the raingauges which lead to a poor record of rainfall at some of the sites. Periods of longer than 24 hours for which there is no rainfall record are listed. (click here to see)

REFERENCES

Bastable, H.G., Shuttleworth, W.J., Dallarosa, R.L.G., Fisch, G. and Nobre C.A. 1993. Observations of climate, albedo and surface radiation over cleared and undisturbed Amazonian forest. Int. J. Climatol. 13, 783-796.

Hodnett, M.G., da Silva, L.P., da Rocha, H.R. and Cruz Senna, R.C., 1995. Seasonal soil water storage changes beneath central Amazonian rainforest and pasture. J. Hydrol., 170, 233-254. aitelli, G.T. and Wright, I.R., 1996. On the climate of a river-side city in the Amazon Basin: urban-rural differences in temperature and humidity. In 'Amazon Deforestation and Climate' (Eds. J.H.C.Gash, C.A.Nobre, J.M.Roberts and R.L.Victoria). John Wiley, Chichester, UK. pp 193-206.

McWilliam, A-L.C., Roberts, J.M., Cabral, O.M.R., Leitao, M.V.B.R., de Costa, A.C.L. Maitelli, G.T. and Zamparoni, C.A.G.P., 1993. Leaf area index and above-ground biomass of terra firme rain forest and adjacent clearings in Amazonia. Functional Ecol., 7: 310-317.

McWilliam, A-L.C., Cabral, O.M.R., Gomes, B.M., Esteves, J.L., Roberts, J.M., 1996. Forest and pasture leaf-gas exchange in south-west Amaz"nia. In 'Amazon Deforestation and Climate' (Eds. J.H.C.Gash, C.A.Nobre, J.M.Roberts and R.L.Victoria). John Wiley, Chichester, UK. pp 265-286.

Roberts, J.M., Cabral, O.M.R. & de Aguiar, L.F. 1990. Stomatal and boundary layer conductances measured in a terra firme rain forest. J. Appl. Ecol. 27, 336-353.

Roberts, J.M., Cabral, O.M.R., da Costa, J.P., McWilliam, A-L.C. and Sa, T.D.A, 1996. An overview of the leaf area index and physiological measurements during ABRACOS. In 'Amazon Deforestation and Climate' (Eds. J.H.C.Gash, C.A.Nobre, J.M.Roberts and R.L.Victoria). John Wiley, Chichester, UK. pp 287-306.

Sa, T.D.A., Costa, P.C. and Roberts, J.M., 1996. Forest and pasture conductances in southern Par , Amaz"nia. In 'Amazon Deforestation and Climate' (Eds. J.H.C.Gash, C.A.Nobre, J.M.Roberts and R.L.Victoria). John Wiley, Chichester, UK. pp 241-264.

SalomÆo, R. de P., 1991. Uso de parcelas permanentes para estudos da vegetacÆo da floresta tropical umida. 1. Municipio de Maraba, Para. Bol. Mus. Para. Emilio Goeldi, ser. Bot., 7: 543-604.

Shuttleworth, W.J., J.H.C. Gash, C.R. Lloyd, J.M. Roberts, A. de O. Marques, G. Fisch, P. de Silva, M.N.G. Ribeiro, L.C.B. Molion, L.D. de Abreu Sa, C.A. Nobre, O.M.R. Cabral, S.R. Patel and J.C. de Moraes, 1984: Observations of radiation exchange above and below Amazonian forest. Quart. J. Roy. Meteor. Soc., 110, 1163-1169.

Wright, I.R., Gash, J.H.C., da Rocha H.R., Shuttleworth, W.J., Nobre, C.A., Maitelli, G.T., Zamparoni, C.A.G.P. & Carvalho, P.R.A. 1992. Dry season micrometeorology of central Amazonian ranchland. Quart. J. Roy. Meterol. Soc. 118, 1083-1099.