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TG-06 Abstract

Vertical Profiles of Carbon Dioxide and Other Trace Gas Species Over the Amazon Basin Using Small Aircraft

Paulo Artaxo — USP - Universidade de Sao Paulo (SA-PI)
Luciana Vanni Gatti — IPEN - Instituto de Pesquisas Energeticas e Nucleares (USP) (SA-PI)
Luiz Antonio Martinelli — CENA - Centro de Energia Nuclear na Agricultura (USP) (SA-PI)
John Bharat Miller — NOAA/ESRL (US-PI)
Pieter P. Tans — NOAA/ESRL (US-PI)

We propose to continue

measurements, as part of LBA-ECO, of the vertical profiles of several

atmospheric trace gas species and isotope ratios, and to develop a capability in

Brazil for long-term measurements of trace gases and CO2 isotopes that does not

currently exist.  On flights using small charter aircraft over the Santarém

Tapajos tower site, and over the Atlantic Ocean off the coast of Fortaleza, we

will measure the mixing ratios of CO2, CO, CH4, N2O, H2 and SF6, the 13C/12C and

18O/16O isotopic ratios in CO2, and the 13C/12C ratio in CH4 in flask samples

collected automatically up to an altitude of about 4 km.  As they are

available, we will use NASA, INPE or other research aircraft to obtain samples

at higher altitudes and other locations.  Flask samples collected over the

Atlantic Ocean and over the forest in the central Amazon basin will enable us to

quantify the change in trace gas mixing ratios and isotopic composition during

the transit of air across the basin.  Other areas will be sampled on a

campaign basis, in coordination with other LBA and Brazilian studies, primarily

to examine the isotopic signature of CO2 exchange in other ecosystem types.

Initially the flasks will be

analyzed in our laboratories in Boulder using existing equipment.  In the

first year of this renewal we will develop the capacity to carry out the trace

gas analyses in the Brazilian laboratories at IPEN, and in the second year we

will upgrade existing equipment at CENA (Universidade de São Paulo) for

measurements of 13C/12C and 18O/16O in CO2 in the flask samples.  Doing the

analyses in Brazil will alleviate very serious problems we have had so far with

shipping into and out of Brazil, particularly with Brazilian Customs, and will

lead to long-term cost savings.  Also, this will provide the expertise for

long-term observations in Brazil that can be integrated into the global

observing network for these trace gases and isotopes, and can be used in other

measurement campaigns.  All species mixing ratios and isotopic ratios will

be firmly tied to internationally accepted calibration scales.  The

observations will constitute the first multi-year time series of CO2, CH4 and

N2O mixing ratios, and CO2 isotopic composition, over the Amazon region. 

Measurements of SF6 will give a sensitive indicator for penetration of northern

hemisphere air into the study area.  The data will provide an important

constraint for regional and global models of these trace gases, and an

independent estimate of regional exchange for validation of scaling of

observations from the flux towers to the whole LBA study area.  In

addition, the payload requirements for our equipment are modest, approximately

60 kg, and our aircraft flights could be a useful resource for other

investigators in LBA.

Our work includes a Training

and Education component that is focused on establishing infrastructure so that

all trace gas and isotope analyses will be done by Brazilian laboratories. 

For long-term (beyond LBA) monitoring in Brazil this is clearly needed for both

logistical and political reasons.  It is very important that we develop

solid calibrations for the measurements made in Brazil and maintain on-going

intercomparison and data exchange between the US and Brazilian laboratories.

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