Although less common (but equally interesting for the in situ investigation of the atmosphere), drifting boundary layer pressurized balloons (BLPBs) offer rare observational skills.
CNES constant-volume balloons are also named BLPBs. Slightly differing versions of BLPBs exist, but the main features have remained the same for all of the 2012/13 field campaigns (Fig.
The buoyancy of CNES BLPBs is set before launch thanks to precise tuning of the helium and air mixture that fills the balloon.
The BLPBs integrate basic atmospheric sensors in their own structure in the form of a scientific gondola.
In the latest version of BLPBs, the data are sampled twice every minute and stored on board.
BLPBs are disposable systems and are not intended to be recovered at the end of their flight.
Measuring anthropogenic influence on nitrogen cycle in BLPB
Human interference on the nitrogen cycle in BLPB is related to a growing economy and its population--approximately 60 million inhabitants--that demands food, raw material and energy.
(2006), this paper aims to evaluate the level of human interference on BLPB's nitrogen cycle due to biological nitrogen fixation (BNF) in cropland and pastures, use of fertiliser in agriculture and anthropogenic depositions (N[O.sub.y] and N[H.sub.x]) derived from consumption of fossil fuel, biomass burning and losses of nitrogenous fertiliser.
Therefore, to calculate the nitrogen input from fertiliser to croplands into the BLPB, it is necessary to estimate the values of several cropland areas in the basin.
We assumed that BLPB is an exporter river basin with the purpose of calculating BLPB's nitrogen outputs.
Therefore, considering our estimate of cultivated area with soybean in BLPB (about 10.8 million ha in 2002), BNF would introduce about 1.83 teragrammes of nitrogen (Tg N) per year.