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Science plan for the
(LBA-CLAIRE)
Prospectus prepared by M. O. Andreae, P. Artaxo,
P. J. Crutzen and J. Lelieveld
12 March 1997
1. Background
The Cooperative LBA Airborne Regional Experiment (LBA-CLAIRE) forms part of the LBA Atmospheric Chemistry Component (LBA-ACC). The following background section outlines the scientific rationale for LBA-ACC, and provides the overall context into which CLAIRE will be integrated.
The tropical regions play a central role in the budget of trace gases and aerosols of the Earth=s atmosphere, as well as in the absorption of solar energy and its transfer into the climate system. The vast regions of highly active terrestrial ecosystems in the wet tropics have a pronounced influence on the global carbon cycle and are important sources or sinks for the long-lived radiatively active "greenhouse gases", such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). They also release large amounts of reactive trace gases, such as nitric oxide (NO) and nonmethane hydrocarbons (NMHC), which figure prominently in the atmospheric oxidation cycles and in the production and destruction of ozone (O3). The tropical region of South America, with the Amazon Basin at its heart, contains the World=s largest area of humid tropical ecosystems, much of which is undergoing profound changes due to human activities. For these reasons, this region has been selected as the focus of intensive scientific investigations under the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA). This experiment takes place in the framework of the International Geosphere/Biosphere Programme (IGBP), and includes studies on ecology, hydrology, meteorology, biogeochemistry and atmospheric chemistry.
Beyond the intrinsic importance of this region for atmospheric science, the Climate Convention requires each nation to determine its contribution to the global inventory of greenhouse gases and the impacts of its natural and industrial emissions on the oxidizing power of the global atmosphere. Currently existing data are insufficient to provide a sound basis for estimates of the net sources from the Amazon region of the key greenhouse gases (CO2, CH4, and N2O), aerosols, or of oxidants and related species (O3, nitrogen oxides, and hydrocarbons). This applies in particular to the effects of the significant changes related to human activities which are occurring in the Amazon Basin, and which could have regional and global effects on climate, on concentrations of greenhouse gases and aerosol particles, and on the oxidizing power of the atmosphere.
The focus of the Atmospheric Chemistry Component of LBA (LBA-ACC) is to provide the foundation of knowledge required to determine net exchanges of important gases and aerosols between the atmosphere and the Amazon region, and, to understand the processes that regulate these exchanges. These processes include climate changes on annual time scales, and the direct and indirect impacts of anthropogenic activity.
The scientific questions asked in the LBA Atmospheric Chemistry Component are:
1. What are the fluxes of the long-lived greenhouse gases (CO2, CH4, and N2O) within the Amazon Basin?
Global atmospheric concentrations of CO2, N2O and CH4 have increased dramatically since pre-industrial times. Forest clearing and agricultural development in tropical forests are often cited as a large net source of CO2 to the atmosphere, with net release estimated at 25-40% of the emissions of CO2 from burning of fossil fuels. The experimental basis for quantitative estimates of the source strength is weak, however. Little is known about the carbon dynamics of tropical soils and almost nothing about rates of carbon accumulation by secondary vegetation. Mature forests have been assumed to exist in a steady state, with no net release or uptake of carbon, but this assumption has never been verified. These questions are central to both the tropical ecological/biogeochemistry and atmospheric chemistry components of LBA, and the experimental design strategies of these two efforts will be closely coordinated to address them.
Data from previous investigations showed that humid tropical forests are significant sources for N2O and CH4, and these ecosystems are widely believed to dominate current natural sources for both . However, regional net emissions are not defined quantitatively, and the responses of emission rates to climate change or to forest clearing and associated agricultural development, land abandonment, and ecological succession, are not well understood.
2. What are the rates of biogenic emission of nitrogen oxides and nonmethane hydrocarbons in the Amazon region and the resulting production (or destruction) of tropospheric O3 and other reactive species?
The tropical troposphere is responsible for about 70% of the global atmospheric oxidation of long-lived gases including CH4, CO, HCFCs, and CH3Br, since the world's highest concentrations of OH are found there. Considerable uncertainty attaches to estimates of photochemical rates, however, because concentrations and sources of NOx, reactive hydrocarbons, and CO are not well-characterized, and OH and HO2 concentrations have not been measured. Current estimates suggest that the humid tropics are vast sources of reactive NMHC, and even relatively small changes in the rates of emission of NOx due to human activities can have a profound influence on the chemical mechanisms by which these substances are oxidized. As a consequence, profound changes in the concentration of ozone and other oxidants, with potentially damaging effects on vegetation and crops, have been proposed.
3. What are the mechanisms and rates of production of biogenic and anthropogenic aerosols in the region, and their influence on radiative fluxes? Does the elemental composition of aerosols play a significant role in nutrient cycling and biogeochemical cycles in the Amazon Basin?
The Amazon Basin is a major direct source of aerosols (primarily organic) to the global atmosphere. Source mechanisms include the production of primary aerosols by vegetation, the formation of secondary aerosols by the oxidation of NMHC, and the burning of vegetation. In addition, ammonia (NH3) emitted from vegetation and soils can modify the content and phase of the atmospheric aerosol. The dynamic equilibrium between gas and particle concentrations is very poorly understood. At the concentration levels observed over the Amazon Basin, the atmospheric aerosol has a pronounced influence on the flux of solar radiation to the surface, and consequently on regional and global climate. The size and elemental composition of aerosol particles are important variables that influence their role as cloud condensation nuclei (CCN). The abundance of CCN and ice nuclei influences the optical and microphysical properties of clouds, and consequently impacts the hydrological cycle and climate. Elements present in aerosol particles such as nitrogen, potassium, and phosphorus, also have an active role in the biogeochemical cycling of essential plant nutrients.
4. What are the rates for the net exchange of greenhouse gases, reactive species, and aerosols between the Amazon region and the global environment?
Atmospheric trace substances produced in the Amazon Basin are transported out of the region by the large-scale circulation over the subcontinent and the tropical circulation in general. Short-lived reactive chemicals enter the upper troposphere mainly over the equatorial area, where deep convection is particularly frequent. Models of the circulation patterns over tropical South America are under development, and will have to be rigorously tested using meteorological observations and chemical tracers. Although aerosols and NH3 are efficiently scavenged by precipitation, export of only a small fraction could make a major contribution to aerosol budgets in the remote atmosphere. This applies in particular to the free troposphere, where there are few other sources of aerosol particles in the tropical regions.
2. Objectives
The objectives of CLAIRE are:
1. Develop an integrated and quantitative understanding of the interactions of biogenic source fluxes, atmospheric transport and vertical exchange, and photochemical processing over the tropical forest
Biogenic compounds, particularly nonmethane hydrocarbons and nitrogen oxides are emitted by the soils and vegetation of the Amazon forest. These substances are subjected to photochemical and dark reactions which result in the production or destruction of ozone, in the oxidation of hydrocarbons, and the production of a variety of gaseous and particulate substances. The exchange fluxes of various trace gases, e.g. CO2, NO, NO2, isoprene, and O3, will be investigated by direct measurements using eddy correlation, or by inference from modeling of their budgets in the boundary layer. These measurements will be linked to flux measurements made at ground level by other groups. To investigate the influence of biogenic sources and atmospheric processing, we will study the evolution of airmasses of marine origin as they move for several days along trajectories reaching into the center of the Amazon Basin.
2. Investigate the vertical transport and processing of atmospheric trace substances from the boundary layer to the middle and upper troposphere by deep convection
Deep convection over the Amazon Basin transports trace substances from the boundary layer into the free troposphere, reaching up to the tropopause region. By this process, considerable amounts of biogenic and anthropogenic substances are injected into the free troposphere, where they may be transported over large distances. At present, little is known about the influence of this transport on the composition and properties of the tropical free troposphere. We intend to characterize the chemistry of the free troposphere over the Amazon Basin, and to study the vertical and horizontal transport of radiatively and chemically important trace substances over and out of the region.
3. Study the sources, chemical composition and physical properties of the atmospheric aerosol over the humid tropics
The humid tropics are considered to be the world's largest source of reactive hydrocarbons. The oxidation of these hydrocarbons results in the formation of secondary organic aerosol particles at potentially quite high rates. In addition, the shedding of microbial and botanical particles from the vegetation is thought to produce large amounts of primary organic aerosol. As a result, the concentration of carbonaceous aerosol over the Amazon Basin is very high, even during the wet season.
3. Implementation
3.1 CLAIRE-1
During the January-April period the airflow over the lowest 5-6 km of the atmosphere is dominated by a NE tradewind flow which transports pristine and humid oceanic airmasses over the forests of Surinam and the Guyanas and from there on into the Amazon Basin, the streamlines (Figure 1) indicating an average flow from the Paramaribo-Cayenne region towards Manaus. Copious emissions of hydrocarbons are expected from the tropical forests, causing a buildup of these compounds and their oxidation products in the boundary layer as it moves downwind. During the CLAIRE-1 mission we intend to measure as many as possible of these compounds in the gas phase and also in the organic fraction of the aerosol.
The area that is selected provides us with a large natural laboratory to determine the emissions of organics that are produced by the forest vegetation. Likewise the area seems excellently suited to study organic transformation processes, probably mostly under low NOx conditions, which may, however, be intermittently disturbed by lightning activity. The measurements of NO/NO2 and NOy which will be conducted on the two aircraft will provide information as to the extent of this. In a similar manner measurements of N2O and CH4 will give information on the release of these compounds by the forest soils. Flights will be conducted in a Lagrangian trajectory, in order to study the temporal evolution of the airmasses and relate these observations to model calculations.
Above 6 km a return flow occurs in the opposite direction (Figure 3), containing airmasses originating mainly from the lowest 5 km over Amazonia, that are strongly processed by clouds and by photochemical reactions. As a result, we will be able to characterize both the composition of the air entering the Basin along one of the major input routes, and of the high-altitude outflow towards the northeast.
We propose to concentrate on flying during days in which minimal precipitation is expected. Because during the proposed period precipitation can be frequent and intensive, actually maximizing in January over Paramaribo, meteorological advice in the planning of the flight schedule will be essential. We envisage to on average on a 50% on/off schedule, which for an experimental period of a month implies a total of 60 flight hours.
3.2 CLAIRE-2
CLAIRE-2 is a campaign designed to study atmospheric properties and processes over the Amazon Basin in the dry season. There are important differences between the wet and dry seasons, related to different atmospheric circulation and biospheric activity patterns. It is expected that the natural emissions from the forest varies significantly between the seasons. In addition there are the biomass burning emissions that are transported over long distances all over the Amazon basin region. Biomass burning is a globally important source of trace gases and aerosol particles to the atmosphere. During previous experiments, most of the measurements were done in the Southern part of the Amazon basin, centered in the Alta Floresta - Porto Velho - Brasilia region. Very few measurements were taken in the northern part of the Amazon basin, where CLAIRE-2 will be focused. The mission objectives include the determination of biosphere/atmosphere exchange using eddy correlation, the characterization of the vertical transport to the free troposphere during the dry season, and the characterization of inflowing and outflowing airmasses.
The CLAIRE-2 experiment will measure atmospheric properties in the region between Manaus - Paramaribo- Belem - Boa Vista. It will have basically the same instrumentation as the CLAIRE-1 experiment. The operational center will be located in Manaus or Paramaribo, depending on the region being explored.
3.3 Meteorological Investigations
In the CLAIRE-1 experiment, most of the meteorological investigations will be coupled with the chemical data analysis phase. Particularly important will be the study of the intrusion of marine air masses from the Equatorial Atlantic Ocean into the Amazon basin. The joint analysis of air mass movement from the ocean with the trace species concentration will be important to link the meteorological component with the trace gas and aerosol chemistry.
At the time of the CLAIRE -2 experiment, most of the large scale meteorological structure will be fully operational, allowing a more detailed analysis of vertical and horizontal distribution of trace gases coupled with transport models.
3.4 Aircraft and Instrumentation
3.4.1 Cessna Citation aircraft
The Cessna Citation-II twin-jet aircraft and its instrumentation is an atmospheric chemistry measurement platform that has been jointly developed by several European groups, mostly in Germany, The Netherlands and Sweden. It has been used since 1991 in free tropospheric and lower stratospheric studies in middle and high latitudes, and it will be used in tropical studies in the near future as well. The speed of the aircraft is 100-200 m/s, although at lower altitudes (e.g., the boundary layer) relatively low speeds (e.g., 50 m/s) are also possible. The maximum flight altitude is 13 km, the maximum payload is 1300 kg. The instrument power supply is 300 A (28 VDC). The aircraft has central facilities such as meteorological measurements, data acquisition system, global positioning and communication systems. The flight range with maximum payload is 2500 km, and the usual duration of a measurement flight is 3-4 hours. A preliminary description of the chemical instrumentation for the CLAIRE-1 campaign is given in Table 3, and a flight schedule is presented in Table 5.
3.4.2 INPE Bandeirante Aircraft
The Bandeirante aircraft is an excellent choice for low altitude atmospheric chemistry surveys. It's range is adequate for local and regional measurement strategy. The INPE Bandeirante plane was already used successfully in several aircraft experiments in the Amazon Basin. The INPE plane for the CLAIRE experiments will be instrumented for measuring several trace gases continuously, as CO2, Ozone, CO, NOx, as well as to collect gas canisters for laboratory analysis of several hydrocarbons. Also several instruments to analyze the aerosol component will be installed: aethalometer to measure black carbon concentration; nephelometer, to measure aerosol scattering cross sections; condensation nucleus counter to measure the total number of aerosol particles; and filters to allow chemical analysis. The GPS installed on the aircraft will give accurate positioning data.
3.5 Flight Patterns
Inflow/Outflow Characterization: Flights will be conducted along the coastline between positions off Georgetown and Macapa (Figure 4). The actual endpoints of the traverses will be decided based on on-site meteorological analysis. The missions will be flown in the form of wall pattern with long level legs to study the composition of the in- and outflowing airmasses at the different altitudes. This will allow the collection of samples which require long integration times such as aerosols) and the investigation of cross-flow gradients. Depending on the availability of the Bandeirante in this region, the missions will be conducted either as two- or one-aircraft operations. If available, the Bandeirante will be assigned the sampling within the boundary layer.
Convective Transport: These flights will be based in Manaus and will investigate specific convective events. They will characterize both the inflow or boundary layer air at the bottom of the convective systems (Bandeirante) and the outflow at their top up to 200 hPa (Citation). The flights will be located over areas of undisturbed forest to the north of Manaus. The specific location will be selected based on the location of the convective systems.
Boundary-Layer Evolution: These flights will investigate the development of a boundary layer airmass during its travel from the coast to the center of the Basin (Figure 4). The two aircraft will conduct alternating vertical sections along the travel path of the airmass, which will be obtained from meteorological analyses. The flights will be based originally in Paramaribo, but end up at Manaus. Depending on the anticipated next flight pattern, the aircraft will be either repositioned in Paramaribo or remain in Manaus.
Survey Flights Within the Basin: These flights are intended to characterize the geographic variability of biogenic emissions and the resulting atmospheric composition, and to tie the airborne observations to ongoing ground-based measurements. Depending on the status of ground operations, flights to Sao Gabriel or Ji Parana may be conducted (Figure 4 and 5). Both aircraft will participate in these missions.
3.6 Meteorological Support
CPTEC will provide logistical meteorological support. This will consist of one or two operational meteorologists helping to plan each of the aircraft missions. At the operational center, products from the CPTEC model will be received via INTERNET, and processed locally in order to design the best plan for the particular mission objectives. This meteorological support is critical to achieve the mission objectives in a efficient way. Radiosonde and precipitation data from several sites in the Amazon basin will be collected at the time of the experiment, in order to help data analysis.
3.7 Ground-Based Measurements
Ground-based measurements on aerosol abundances, composition, and optical properties, of the concentrations and fluxes of various trace gases, and of the chemical composition of precipitation will be conducted at a number of sites in Brazil, and possibly also in Venezuela and other countries in the region. These data will allow us to put the results obtained during CLAIRE into a larger temporal and spatial context. When the technologies for airborne flux measurements using eddy correlations have been implemented on the Citation, flights will be conducted in the areas where ground based flux measurements are being performed. This will serve to cross-calibrate airborne and ground-based flux measurements and to extend the results from the ground-based measurements to the landscape scale. Weather and Doppler radar will be operated in Guyana in support of meteorological investigations and flight campaigns
3.8 Modeling
3.8.1 Mesoscale modeling
In order to study the relationship between measurements, emission factors and transport, mesoscale models will be used. The RAMS (Regional Atmospheric Modeling System) model will be used for this purpose. It is implemented at the Department of Atmospheric Sciences, University of Sao Paulo, and also at the CPTEC/INPE (Centro de Previsao de Tempo e Mudancas Climaticas). At the CPTEC the mesoscale model ETA will be used coupled with a tracer model. The ETA model will be coupled at the surface with the SiB model in order to have an adequate description of the vegetation characteristics. Also all the normal products from the CPTEC GCM model will be used, as the wind fields at various levels, precipitation and pressure 24 hours forecast. The RAMS model can be used with a fine grid over small areas for detailed study of local and regional transport. The dispersion module of RAMS can be used to study the transport of conservative species over most of the South America regions. Backward and forward three dimensional trajectory analysis will be calculated for most of the aircraft sampling areas, in order to study the source regions of the sampled air masses. This component will be done by CPTEC/INPE, DCA/USP and IF/USP, with help from the group of Anne Thompson at NASA Goddard and other European groups. Other possibilities that are in the implementation process at CPTEC are a CO2 model coupled with the ETA model.
3.8.2 Regional to global scale modeling
The research aim is to integrate the measurement results on regional and larger scales and provide boundary conditions for the mesoscale modeling. Thus the chemistry and transport of biogenic and anthropogenic trace gases and aerosols over the northern part of South America and beyond will be modeled to assess their role in the tropical and global environment.
The main modeling tool applied is the chemistry-general circulation model ECHAM. The model can be run at different resolutions, i.e. from T30 (3.75 degrees) up to T106 (1 degree). The number of vertical levels can be either 19 or 39 (up to 10 hPa). The GCM has been coupled to a chemistry model that accounts for CH4, CO and NMHC breakdown and photochemical O3 formation/destruction in the troposphere. Long-term simulations are usually performed at T30 resolution, however, studies that focus on regional scales are performed for periods up to a few months at T106 resolution.
Currently, model simulations are performed without considering short-term interactions between emission and deposition fluxes. These interactions depend strongly on the chemistry and turbulent exchange within and above the canopy. An additional important aspect is the interaction between chemistry and turbulence. The development of a 1-D version of an integrated atmosphere-biosphere model that accounts for these processes is in progress. It includes realistic representations of NO and isoprene emissions from soils and the vegetation. This model will be tested against available field data, in particular from LBA. Subsequently, the model will be included into the GCM and further validated against LBA measurements. This will be done on the basis of actual meteorological fields (dynamic adjustment of the GCM at high resolution), so that realistic comparisons of the model results with measurements can be performed. The model will also be compared with the aircraft measurements in the free troposphere, in particular to test the model convection scheme. Ultimately, the model will be used to assess the role of biogenic and anthropogenic (pyrogenic) trace gas emissions from the Amazon basin in the budgets of reactive carbon, nitrogen and ozone, and the atmospheric oxidation efficiency on regional and global scales.
3.9 Training Activities
Much of the research conducted during CLAIRE will be implemented by graduate students and postdoctoral researchers. It is anticipated that a large proportion of these will come from Brazil and will be trained for measurement techniques and data analysis at the European partner institutions, wherever appropriate. These junior researchers are also expected to play a major role in the post-campaign data interpretation phase, where they will be instrumental in maintaining an active flow of information and ideas between the European and Brazilian partners.
Table 1. Aircraft Characteristics
Cessna Citation II Bandeirante EMB 110
Engines Twin jets Twin turboprop
Range 2000-2500 km 800 km
Speed 100-200 m/s
Maximum altitude 12-13 km 4-5 km
Maximum payload 1300 kg
Instrument power supply 300A @ 28 VDC
Data acquisition central
Navigation GPS
Table 2. Science Team
Name Institution e-mail
Ammann, Christof MPI Chemistry ammann@mpch-mainz.mpg.de
Andreae, Meinrat O. MPI Chemistry moa@mpch-mainz.mpg.de
Arnold, Frank MPI Nuclear Physics
Artaxo, Paulo U. Sao Paulo artaxo@if.usp.br
Crutzen, Paul MPI Chemistry air@mpch-mainz.mpg.de
Fischer, Horst MPI Chemistry hofi@mpch-mainz.mpg.de
Hansson, H.C. U. Stockholm, Sweden hc@misu.su.se
Helas, Günter MPI Chemistry gth@mpch-mainz.mpg.de
Kelder, Henning KNMI, Netherlands
Kirchhoff, Volker INPE kir@spd.inpe.br
Kley, Dieter KFA Jülich
Lacaux, Jean-Pierre U. Toulouse lacjp@aero.obs-mip.fr
Lawrence, Mark MPI Chemistry
Lelieveld, Jos U. Utrecht lelieveld@fys.ruu.nl
Lindinger, Werner U. Innsbruck, Austria
Maenhaut, Willy U. Gent, Belgium MAENHAUT@inwchem.rug.ac.be
Moortgat, Geert MPI Chemistry
Penkett, Stuart U. East Anglia M.Penkett@uea.ac.uk
Sanhueza, Eugenio IVIC, Venezuela esanhuez@ivic.ivic.ve
Setzer, Alberto INPE asetzer@ltid.inpe.br
Silva Dias, Maria Assuncao U. Sao Paulo mafdsdia@model.iag.usp.br
Silva Dias, Pedro da U. Sao Paulo mafdsdia@model.iag.usp.br
Ström, Johan U. Stockholm johan@misu.su.se
Surinam Meteorologist
Tavares, Tania U. Bahia
Thompson, Anne NASA Goddard thompson@gator1.gsfc.nasa.gov
Valdez, Juan
Vanni Gatti, Luciana IPEN lvgatti@net.ipen.br
Vega, Oscar IPEN
Table 3. Citation aircraft instrumentation
Measured Technique Institute (investigator)
CO2 infrared analyzer MPI Mainz (Fischer)
CO, CH4, C2H2 tunable diode laser spectrometer MPI Mainz (Fischer)
HNO3, SO2, (CH3)2CO, H2O2, DMS, HCN etc. mass spectrometer MPI Heidelberg (Arnold)
NOx chemiluminescence UEA, Norwich (Penkett)
NMHC Canisters, in situ GC? UEA, Norwich (Penkett)
NMHC Mass spectrometer U. Innsbruck (Lindinger)
NOy species (incl. PAN) ? UEA, Norwich (Penkett)
H2O ? FZ Jülich (Kley)
O3 chemiluminescence IMAU, Utrecht (Lelieveld)
JNO2 photo-optical detectors IMAU, Utrecht (Lelieveld)
Aerosols CN counter, DMPS, optical particle counter MISU, Stockholm (Strom, Hansson)
Aerosol scattering, absorption nephelometer/aethalometer MPI Mainz (Andreae)
Aerosol size laser-optical counter (PCASP) MPI Mainz (Helas)
Aerosol composition impactors/filters USP, Sao Paulo (Artaxo)
Table 4. Bandeirante Instrumentation
Measured Technique Institute (investigator)
CO2 infrared analyzer INPE/MPIC
CO gas chromatography INPE/MPIC
NOx chemiluminescence MPIC
CH4, NMHC Canisters INPE/MPIC
H2O ? INPE/MPIC
O3 chemiluminescence MPIC
O3 UV absorption INPE
Aerosol number CN counter MPIC/USP
Aerosol scattering, absorption nephelometer/aethalometer USP
Aerosol size laser-optical counter (PCASP) MPIC
Aerosol composition impactors/filters USP
Table 5. Citation aircraft schedule (66 flight hours)
Project day Location Flight type Flight hours
1-5 Amsterdam instrument integration -
6 Amsterdam-Dakar transit 6
7 Dakar-Paramaribo transit 5
8-15 Paramaribo build-in instruments -
15-17 Paramaribo test flights 3
18 or 19 Param.-Belem-Paramaribo coastal survey, BL + FT 4
20 or 21 Param.-Manaus-Paramaribo boundary layer 4
22 or 23 Param.-Manaus-Paramaribo BL and free troposphere 4
24 or 25 Par.-Manaus-Boa Vista-Par. boundary layer 4
25 or 26 Par.-Manaus-Boa Vista-Par. BL and free troposphere 4
27 or 28 Param.-Belem-Manaus boundary layer 4
29 or 30 Manaus-Belem-Manaus BL and free troposphere 4
31 or 32 Manaus-Param.-Manaus free troposphere 4
33 or 34 Manaus-Boa Vista-Manaus free troposphere 4
35 or 36 Manaus-Paramaribo free troposphere 2
37 or 38 Param.-Belem-Paramaribo coastal survey, BL + FT 3
39-41 Paramaribo take out instruments -
42 Paramaribo-Dakar transit 5
43 Dakar-Amsterdam transit 6
44 Amsterdam take out instruments -
Figure 1: Airflow patterns at 1000 hPa over North and South America during the period February/March 1994 (Figure courtesy of R. Newell)
Click here for Picture
Figure 2: Airflow patterns at
500 hPa over North and South America during the period February/March 1994 (Figure
courtesy of R. Newell)
Click here for Picture
Figure 3: Airflow patterns at
200 hPa over North and South America during the period February/March 1994 (Figure
courtesy of R. Newell)
Figure 4: CLAIRE-1 Operating area and potential flight tracks.
Figure 5: CLAIRE-2 Operating area and potential flight tracks.
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