In science, any experiment is only considered credible, if it can be replicated. HALO’s task today was to replicate the tracer experiment AC11 from 16 September. The tracer was released again from the top of the Park Suites Hotel at about 0600L. HALO took off under the leadership of Hans Schlager at 1047L (1447Z). The team began by taking air samples for tracer measurements at 2000’and 4000’ in an area west of Manaus, and then climbed to 35,000’, heading east in the hopes of finding big cumulus clouds to investigate. The satellite image to the left shows the flight track and the Cb clouds that were sampled during this flight.
It turned out that there were no clouds big enough to be of interest in the east, so HALO turned around to go to a big cumulonimbus (Cb) cloud that had been spotted southwest of the city. The aircraft descended into the boundary layer at 4000’ to sample the air at low levels, and then began to probe clouds at 4500’ from 1700Z to 1720Z. Since the whole central Amazon Basin has been surprisingly dry now for days, fires began to be lit everywhere, particularly in the inhabited rural areas surrounding Manaus.
After these measurements at low level, HALO climbed to the top of the large Cb cloud and made measurements in its outflow anvil between FL310 (31,000’) and FL390.This took until 1846Z, and yielded beautiful data as well as beautiful views.
The next task now was to find the tracer again, that had been drifting through the air since morning. Model calculations predicted that some of it had been sucked into a big cumulus cloud west of Manaus, and to test this prediction, HALO took samples in the outflow from this cloud at FL370 between 1903Z and 1940Z. The flight concluded by additional tracer sampling at low levels and cloud probing at 6000’. Landing was at 2110Z.
Photos: Hans Schlager
Photos: Hans Schlager