The West African pilot balloon network during the NAMMA-2006 and
implications for the future of the African pilot balloon sounding
network

Michael Douglas^1^, John Mejia^2^, Jose Galvez^2^, Javier Murillo^3^

^1^National Severe Storms Laboratory/NOAA, ^2^Cooperative Institute for
Mesoscale Meteorological Studies and University of Oklahoma, ^3^Weather
Decision Technologies

Norman, Oklahoma

**Introduction**

The National Aeronautics and Space Administration (NASA) -- African
Monsoon Multi-disciplinary Analysis) (AMMA) field program (NAMMA
hereafter) was carried out in west Africa and over the eastern tropical
Atlantic during August and September 2006 to improve our understanding
of the genesis of tropical storms over this region. The main focus was
on the role of dust and the variability of African easterly waves in the
cyclogenesis.

The primary components of the NAMMA were the NASA DC-8 research aircraft
and the meteorological radars based in the Cape Verde Islands at Praia
and near Dakar, Senegal. However, a small effort was supported to
upgrade the sounding network in countries of west Africa, specifically
Mali, Mauritania, Senegal, and Guinea. The objective was to improve the
synoptic specification of the African waves leaving the continent to
help plan the DC-8 flight missions and to support studies to describe
the upstream conditions prior to cyclogenesis over the Atlantic.

Because of the limited funds available, the effort mostly involved
trying to bring the existing pilot balloon network over the region up to
its former status. This summary describes this effort. It also suggests
where the future may lie with regards to the network, based on our
experience. More information on our activities may be found at:

<http://www.nssl.noaa.gov/projects/pacs/web/NAMMA/e_introduction.html>

The pilot balloon network in West Africa has been in place for more than
50 years, and in the past the network was characterized by relatively
frequent observations (often 4-times daily) and with high spatial
density (more than 20 stations in West Africa). However, the pilot
balloon network has decayed in recent decades. Unfortunately it is
difficult to describe this decay in detail because much of the
observations were not transmitted in real-time and many of the
observations have not been digitized and made available in digital
archives.

Some details of the effort to improve the network in west Africa prior
to the NAMMA aircraft activities are described in an abbreviated, but
still lengthy, report in Appendix 1. This provides the flavor of what
can happen in an effort that in retrospect allowed too little lead time
and was short of resources. Despite our considerable experience in
working in Latin America, we were not fully prepared for the experiences
we encountered in west Africa.

**Implications for the pilot balloon network in west Africa**

Our experience with the seriously decayed pilot balloon network we found
during NAMMA does not mean that the observations should be abandoned. In
the relatively cloud free environment of the region there would be
considerable benefit to having a relatively dense upper wind network.
The intensity of tropical waves cannot be adequately described from the
current winds over the region; the small scale of the vorticity features
cannot be well-resolved from the radiosonde network alone.

Reducing the pilot balloon network's glaring problems -- lack of gas and
poor data quality being two major problems, is an urgent problem.
Fortunately, the gas supply problem can be dealt with by either 1)
importing gas cylinders from a central source where it can be produced
inexpensively (Europe or the US) or 2) using new technology gas
generators to generate on demand the gas needed for balloon inflation. A
system now being tested (<http://www.hydrogenpowerinc.com/index.html>)
appears to be fully an order of magnitude less expensive to purchase
than current caustic soda generators, and as economical to operate as
importing gas cylinders. The availability of an inexpensive and
convenient hydrogen source to inflate balloons in remote locations is
the largest problem blocking a significant upgrade of the pilot balloon
network in the region.

To improve data quality of pilot balloon observations requires regular
maintenance of the theodolites and calculation of the winds with
computer software that displays and interactively corrects the raw angle
data if errors are detected. Currently no error-dectection is possible,
with raw angles being entered into a hand calculator and the winds
immediately calculated. A keypunching mistake or an incorrect reading
from the theodolite cannot be easily detected (or corrected).

**Implications for future radiosonde and pilot balloon activities in
west Africa**

The ASECNA[^1] oversees radiosonde observations in many African
countries. This has been the case since independence, and is a realistic
recognition that each country by itself might not be able to maintain
the meteorological networks needed for civil aviation purposes. This
arrangement appears to have worked well, and the current radiosonde
network is thus somewhat insulated from the economic difficulties of
meteorological services in any of the particular countries.

Our original impression was that the problems with maintaining the
sounding network in west Africa (both radiosonde and pilot balloon) was
due to the non-participation of the individual meteorological services
in operating the sounding network. We believed that if each country made
the observations, and then used them for forecasting, they would
individually see the value of the observations and help support the
stations. ***We no longer believe this to be the best strategy.***

Our experience in upgrading the sounding network in west Africa for
NAMMA suggests that a radiosonde network for Africa should be operated
by a organization that would be essentially *independent* of national
meteorological services. Such an organization should have authority to
establish and operate sounding sites based on the overall benefit to
numerical weather prediction on a regional to global scale.
Recommendations from a "scientific oversight committee", rather than
from individual met services, would be used to locate stations.

While somewhat radical, our suggestion is similar to what ASECNA is
already doing in much of west Africa. It is also exactly what the
NOAA-funded PACS-SONET project did for approximately 10 years in Latin
America with pilot balloon observations (which motivated our African
work and also this article). It makes little sense to have some
countries, because of their favorable economic status, establishing many
stations while their neighbors cannot afford -- or chose not to support,
any stations. It will be *very difficult* to convince all countries in
Africa to agree to financially support a radiosonde and pilot balloon
network of uniform density for weather forecasting purposes. This would
put a major burden on large, relatively poor countries. And very few
countries will be willing to support radiosonde observations in a
neighboring country that chooses not to make such observations. The only
feasible solution to establishing an adequate and uniform network over
the continent is to support the network with external funds, and to then
run the network for the purposes of NWP and climate monitoring, and
fully independent of the host countries. In this sense the network would
be little different than a multinational corporation. Satellite
observations are provided for Africa by EUMETSAT, the US distributes
WAFS data globally, and the US provides polar orbiting satellite for the
entire world. Thus, there is no essential reason that atmospheric
sounding observations must be made by a National Meteorological Service,
if they can be more effectively carried out by another organization.

By contracting individuals to make the soundings, it would actually be
possible to increase the likelihood of reliable observations. Observers
could be paid a good wage (as opposed to very poor salaries of
government workers in many NMS's), and rotated periodically from remote
locations to more central locations. Such an organization would
essentially be a meteorological service, but focused on making and
distributing the observations. It would ensure a more uniform
distribution of stations, and maximal impact on continental and
global-scale numerical weather prediction.

If establishing an organization to oversee and operate the sounding
network over much of Africa sounds too complicated, the alternative is
to make mutual aid arrangements with many of the approximately 53
countries that comprise Africa and then to somehow enforce the operation
of these stations. The most effective solution should be to obvious to
anyone with any international experience.

The existence of such an internationally-funded organization to make
radiosonde soundings does not mean that individual countries could not
operate their own sounding networks. If the basic sounding network was
perceived as not sufficiently dense for good limited area forecasts, an
individual NMS could always fund its own stations.

**APPENDIX 1:** **Summary of efforts to strengthen the existing pilot
balloon and radiosonde network in West Africa for the NASA-AMMA field
program.**

*Note: photos illustrating the following activities can be seen at:*

<http://www.nssl.noaa.gov/projects/pacs/web/NAMMA/e_photos.html>

Prepared by: Michael Douglas, National Severe Storms Laboratory/NOAA,
with

assistance of Javier Murillo, Jose Galvez and John Mejia,
CIMMS/University of Oklahoma

In April 2006 we[^2] received notification that we would be funded to
establish a pilot balloon network in western Africa to describe the
intensity of tropical waves propagating over the region prior to their
emerging over the eastern Atlantic Ocean. Due to time and funding
limitations we decided to focus our attention on four countries:
Senegal, Mauritania, Guinea, and Mali. These countries already had
existing upper-air stations and a history of making both pilot balloon
and radiosonde observations. Guinea, which had not made soundings in
some years, was chosen because of the NAMMA community perceived this
area to be important, as few observations were available south of
Senegal in west Africa (see Fig. 1).

**Historical setting**

Many aspects of the AMMA field program were discussed during an AMMA
Scientific Conference held in Dakar in December 2005. A poster was
submitted to this conference with the focus on the importance of
upgrading the pilot balloon network prior to the AMMA field phase. At
the time of the conference the Principal Investigator (PI) (MD) was
unaware of the possibility of any funding for such an activity, but had
been encouraged to attend by European counterparts who were organizing
the sounding component of AMMA.

At the Dakar meeting the PI became aware of a call for proposals related
to the NASA-AMMA effort (NAMMA) which was focused on studying the
downstream development of tropical waves into tropical storms over the
eastern and Central Atlantic Ocean. A proposal was formulated that
proposed describing the wave intensity over west Africa, combined with
aircraft observations of the wave over the ocean with the NASA DC-8
aircraft. This proposal was funded, and notification of the proposal's
acceptance was received on April 25^th^.

A science conference was rapidly organized by the NAMMA Chief Scientist
(Ed Zipser, U of Utah) and a two-day meeting was held at Howard
University in Washington DC on June 4-5^th^. At this meeting was Jean
Blaise Ngamini, the AMMA representative from ASECNA, the Agency
responsible for coordinating Aviation activities (including meteorology)
for some 16 countries in Africa and in Madagascar. Mr. Ngamini was
coordinating the ASECNA sounding network for the AMMA activities, and
provided information on the current situation in west Africa as it
related to NAMMA. Mr. Ngamini provided us with details of the ASECNA
network and mailing addresses for each of the countries involved.

In June 2006 we purchased 5 additional (used) theodolites from an
individual who has these and maintains a web site dedicated to
meteorological theodolites. These used theodolites averaged \$1000 each,
versus \$8000 for new theodolites. The theodolites and the necessary
30gm balloons were shipped about 1 week prior to our departure for
Senegal, which in retrospect, allowed too little time. The first
shipment, of three theodolites and balloons to Senegal, was mis-routed
by FEDEX's European collaborator and was sent *twice* to Johannesburg,
before being sent to Dakar, arriving 10 days late.

![](media/image1.jpeg){width="3.2in" height="2.058333333333333in"}

*Fig. 1. The planned network, prior to the set-up. Names that are
crossed-out were discovered in the field to be impractical to establish.
Dakar was also a pibal site.*

**Establishing the stations**

Our NSSL group, consisting of myself[^3], PACS-SONET coordinator Javier
Murillo, and two University of Oklahoma graduate students with
considerable field experience in Latin America (Jose Galvez and John
Mejia) traveled to Dakar, Senegal on July 10^th^. Our intention was to
determine the current status of the sounding network, and establish the
Senegalese component first, and then travel to the surrounding countries
as appropriate. The International headquarters of ASECNA is in Dakar,
and their collaboration was viewed as valuable to contact each of the
participating countries and to make the travel and training
arrangements.

Because of the mis-shipment of materials to Senegal, and also because of
the difficulty in determining, from Dakar, the situation in each
country, we were delayed in traveling to the other countries in the
region. In addition, we needed to obtain permission to establish the
observations and travel to the stations within Senegal (4 sites,
including Dakar) and a meeting the National Meteorological Service was
required. Although one Senegal site was visited early (Ziguinchor) and
the observers trained and motivated, observations did not begin until
approval was given, after a meeting with DMN Director on Aug 8^th^, at
which payment of the observers was discussed.

![](media/image2.jpeg){width="3.1284722222222223in"
height="2.3569444444444443in"}

*Fig. 2. Example of radiosonde observations arriving via GTS on Sept 27,
2006 at 12Z. The blue dots are stations that have equipment, and may
often be making observations (except if gas shortages exist), but whose
observations have not been arriving via GTS in recent months. Note the
non-uniform distribution of stations, which lie on E-W line.*

While waiting for information and the arrival of our shipped materials
in other countries, we arranged to have a technical expert in the Met
Service of Guinea visit Dakar (at our personal expense) to bring old
cylinder heads and to provide training with the Dakar radiosonde
station. This person, we were to discover later, was key to establishing
the radiosonde station in Conakry. Unfortunately, the two cylinder heads
he brought to Dakar for testing did not work well (they leaked), and we
had to order two replacement heads from the Manufacturer, SAGIM, at
their (from our perspective - inflated) price of \$1500 each.

**Mali**

Because time was evidently running short (we had purchased restricted
tickets from the US to Senegal to save \~\$1000 per airfare for each of
the 4 official team members), we arranged for travel to Bamako, Mali, on
July 25^th^. A meeting was organized for the following morning to
discuss our project and the plan to establish the three proposed pilot
balloon sites in Mali. The first item to be discussed, after our
explanation of the project, was the payment to the DMN and its
personnel. After hearing that air travel to the two sites outside of the
main city (Bamako) was irregular and not daily, we discussed ground
transport to the sites. An individual was assigned to each of our two
teams, which would travel via rental vehicle to the two distant sites
(Mopti and Kayes, approximately 500-700 km from Bamako-see fig 2). We
were to provide per diem for each individual accompanying us and we
needed to rent the vehicles. Unfortunately, rental vehicles were not
inexpensive, and with driver amounted to \$500 for each 4x4 vehicle for
the required 3 days.

The training at the ASECNA pilot balloon site at Mopti went well, as the
site was in perfect working order, with gas, balloons and a new
theodolite, which had been received within the past 6 months. However,
they could not use the theodolite because no one had been sent from the
ASECNA headquarters in Dakar to determine the north and otherwise set it
up. The observers complained also of insufficient personnel to make
pilot balloon observations (only three persons were present, including
the one in charge of preparing gas and inflating the balloon, who could
not read.)

The travel to the other Mali site, at Kayes, was less fruitful. After a
7 hr drive, including a 2-hr stretch of dirt and mud, we reached the
Kayes site. The site was essentially abandoned. Although the excuse was
that the site was going to be moved soon to a relatively new airport
location, the instrument shelter and all other facilities were in very
poor condition. The last time a pilot balloon had been launched at the
station was 18 years earlier! The cylinders and supplies, which we had
been told were in good condition, were useless. Apparently the observers
had been led to believe that we would provide everything needed to make
the observations. We returned to Bamako the following morning, unable to
do any training.

As we were to arrive back in Bamako on Friday afternoon, July 27^th^ -
one day earlier than expected, we had the AMMA Mali representative with
us on our trip to Kayes call via cell phone to arrange a training
session at the Bamako radiosonde site on the weekend. In this manner we
could train the Bamako observers in using a replacement theodolite that
we had brought to Mali with us. However, on Friday evening (several
hours after we had returned) two individuals from the DMN arrived at our
hotel and met with us for a few minutes. They had concluded that
training on the weekend was not feasible. No specific reason was given,
and we could obtain none from them. We were disappointed, since we had
our return flight to Dakar on Sunday afternoon, and this meant we would
not be able to set up the Bamako theodolite site without extending our
stay, which was already longer than desired.

Out of some desperation we decided to call one of the individuals that
had participated in our first meeting, and for whom we had a telephone
number - and we explained the situation. He expressed surprise, and
thought the training had already been arranged for the weekend. He said
that we could come and train on Saturday morning.

We arrived on Saturday morning, and after some effort, replaced the old
theodolite (which lacked a working high magnification lens) with our
better-condition theodolite. The first pibal observation made with the
newer theodolite lasted 40 minutes, compared with an average of 10
minutes with the previous theodolite. This generated a vocal complaint
by the station chief that the observers would need to be paid overtime
for these observations, since they were accustomed to 10-15 minutes.
Fortunately, at the end of the training session it appeared that
observations would be made at Bamako.

Interestingly, while visiting ASECNA's Bamako airport forecast office
during a break in the training session, we noticed that radiosonde
observations from Timbuktu were being plotted. We were unaware that this
site was even functioning, since observations were not being transmitted
over the GTS. The staff mentioned that Timbuktu had been making
radiosonde observations for many months -- yet their observations are
not available outside of the region. Had we known that Timbuktu was
working well, we might have revised our Mali observing network.

The return to Dakar was eventful only in that one of the members
discovered shortly before leaving for the airport that they had
misplaced their hard copy ticket. At the airport, Air Senegal said that
purchasing another ticket was required, and no refund was possible
unless a police report had been made in downtown Bamako. As this would
have required we miss our flight, there was no practical option but to
buy the ticket. We have not see such a police report requirement in any
other country, but it reminded us that paper tickets (e-tickets are
unavailable) are just like cash in some countries.

We remained in Dakar one day, arranging our travel to Guinea and
Mauritania. Because of the limited time available for the set-up of the
stations, we split into two groups, one group traveling to Conakry,
Guinea and the other to Nouakchott, Mauritania.

**Mauritania**

The Mauritania team (MD, RD, and John Mejia) were met on arrival by
ASECNA personnel at the airport and taken to the hotel. The following
morning we met with the ASECNA director, who spoke fluent Spanish, so we
communicated in Spanish rather than French, and he translated the
essence into French for his staff. We also met with the Met director and
all other staff of the Nouakchott meteorology office. The radiosonde
site had not made observations for several months due to a shortage of
gas generation materials, but a shipment had just arrived (sent from
Dakar at our instigation -- a much larger shipment had been delayed in
France for some time). Gas cartridges were being sent also to the
northern radiosonde site of Nouadhibou, via truck, and were sufficient
for training and some launches there.

The Nouakchott site was well maintained and run in a relatively
exemplary manner. The building was quite new and the hydrogen generators
in good condition. The theodolite worked well, though our replacement
theodolite could provide more accurate reading -- if the observers would
persist in being trained on it (it was an unfamiliar design to them).

We immediately became aware that not only low clouds, but heavy dust,
could limit pilot balloon observations in Mauritania. The observers had
been making pibals in previous months -- before the gas supplies ran
out, but few soundings exceeded 4 km.

The observers were trained with our software to calculate the winds,
this software was installed on the computer that was used for making the
radiosonde soundings. Although the observers were trained to process the
pibal data in this manner, rather than use their hand calculator, the
main problem was in transmitting the data. Observations had not been
received from either Mauritania site for some months, and they claimed
that there was a problem between Mauritania and Dakar. We suggested
using internet to send the data - but the nearest internet was a half km
away at the airport terminal building and they said they could not
routinely do this -- perhaps once per week. Some observers were more
willing than others to help out -- our personal observation was that the
workload was very light and most of the time was spend sleeping/resting
or eating/preparing tea while waiting for the next synoptic observation.
This was in fact the case at most synoptic stations -- there was simply
little to do between observations.

After discovering that air transportation to Nouadhibou was infrequent,
we arranged for ground transport via the private car of an ASECNA
administrator, who drove us. There were numerous military and police
checkpoints along the lightly traveled desert road, so it was important
to have a French/Arabic speaking person along.

Once in Nouadhibou, we met with the subdirector of the station and
agreed to a training session the following day. Initially, we selected a
site on the roof of the radiosonde inflation shelter, but this site was
in a residential neighborhood a few hundred meters away from the airport
terminal building. This site they considered not secure for the
equipment, because it could not be locked up easily. They suggested the
airport met station, which, despite being an open site, had 24-h guards.
However, they had to move one gas generator to the site, which
complicated the inflation of the radiosonde balloons (two cylinders are
needed for inflating radiosonde balloons since one cylinder is good
enough for filling about 1.5 balloons). Thus, the pilot balloons were
inflated at one location and the radiosondes at another site. (This was
also the case in Dakar.)

We replaced the theodolite at Nouadhibou since their theodolite was in
worse condition, but they showed some reluctance to learn the new
procedures required. Eventually they realized that it was easier to
obtain the decimals degrees with the replacement theodolite. The staff
(everyone from the site participated in the training) spent considerable
time with the software to process the winds -- they appreciated the ease
by which bad data could be corrected. Fortunately, internet was
available in the Director's office, and they learned how to send the
data shortly after the observation was made. Nouadhibou was the most
successful of any site in transmitting the data in near-real time.

We returned to Nouakchott feeling that we had been successful overall in
Mauritania, and both radiosonde sites seemed to be able to make
observations, in addition to the 06 and 18Z pilot balloon observations.
Our only concern was whether the gas charges would arrive in time for
the sites to continue making radiosonde observations.

**Senegal**

We had already examined the Dakar pilot balloon site shortly after our
arrival in Senegal in July. Although imperfect in several aspects,
observations were seemingly being made there, at least from time to
time. The theodolite was eventually replaced by one of ours, and our
team members installed and trained the observers in the use of our
software to quality control the data.

More difficult was the training of the Senegal sites outside of Dakar.
One team that traveled to Tambacounda, the Senegalese radiosonde site
300km east of Dakar, was not allowed to train the station staff -- only
the station chief, because the training had not been approved and
notification had not been given. (The team had asked ASECNA-Senegal
personnel to contact the station prior to leaving, but the responsible
person was at a meeting, did not get the message, and did not contact
the station.) Thus, this site was inadequately trained, despite being
ready to make pilot balloon observations. Our team members (JM and JG)
wondered why observations were not being made, since everything at the
station seemed to be working.

On return to Dakar from Mauritania we discovered that no observations
had yet been made in Senegal. We met with the Director of the met
service; the main concern was that no financial payment to the observers
had been discussed, so no observers had been told to make observations
and they were waiting for instructions. After ensuring, via phone calls
from the DMN headquarters, that we would be expected, we arranged to
travel to the northern Senegal pilot balloon site at St Louis on Aug
8^th^. This was a site that had previously (in years past) made
observations, but the theodolite apparently had developed problems.

Traveling via rental vehicle (with driver) we arrived in St Louis in
only 3 hours, and went directly to the airport observation site[^4]. The
facilities were relatively well-maintained, but the most serious problem
was the lack of gas. The gas generator could not be cleaned well for the
lack of a cleaning brush, and gas had not been generated in 3 years.
(The observers pointed to a hole in the concrete ceiling where the
cylinder head had flown off from the last explosion -- due to incomplete
cleaning of the cylinder.) There was still a small amount of gas in the
cylinder, and we managed to make 6 practice balloon launches for
training the observers with the new theodolite (again, the old
theodolite lacked a good high magnification lens). We trained the
observers to process the observations with our software on their new
computer -- they had received the computer recently but no one had come
from Dakar to set it up, so it had remained in the box until we unpacked
and prepared it for them.

At the conclusion of our Senegal activities, and when we left on August
10^th^, we still did not know if the Senegalese sites would function.
They had supplies, balloons, gas (except for St. Louis) -- only the
willingness to make the observations was not guaranteed. As of this
writing (Dec 4^th^) we have not received any indication that
observations have been made in Senegal at any of the 4 potential pilot
balloon sites.

**Activities in Guinea and the radiosonde site at Conakry**

Two team members (Jose Galvez and Javier Murillo) arrived in Conakry on
July 31^st^. They prepared the following summery of their experience...
The deputy director Yaya Bangoura, Mr. Momo Camara, one driver and one
person in military uniform met us at the airport. We had met Mr. Camara
previously in Dakar since he traveled there to bring the hydrogen
generator heads and to inform us about the status of the Guinean sites.
Mr. Bangoura had been in contact with us via email and telephone and
made all the arrangements for our visit.

In the hotel we noticed how unreliable electric power was in Guinea.
During the peak hours, the hotel was fed by an emergency generator that
ran overnight on a regular basis. Although our impression was slightly
different the night of our arrival, the next morning we realized that
Guinea was the least developed of the three countries we visited during
this trip. The trip from the hotel back to the weather service's office
in the airport revealed the extent of the economic crisis in this
country.

The weak infrastructure is not limited to the electric system. At the
hotel, for example, we were told that credit cards would be accepted as
a payment method, but days later, at check out, the hotel clerks
couldn't communicate with the bank (using a cell phone) to validate the
credit card. Since ATM's do not work with foreign cards in Conakry and
we didn't have enough cash they have to reluctantly accept the credit
card vouchers and let us leave the hotel (and the country) without them
being able to validate the cards.

The weather service's entire staff in Conakry (about 10 individuals) are
apparently working at the airport. The Direction Nationale de la
Meteorologie (DNM) is supposed to function from another building near
downtown, but we visited the facilities and they looked abandoned,
lacking basic services like telephone lines and even electricity. At the
airport, the DNM have a private office, and another working area divided
in a cubicle for computers and a small classroom with a desk, some
chairs and a board. They have Internet access and computer equipment to
display satellite images, but we saw not much evidence of charts,
bulletins, or telephone calls requesting data or products, things one
normally sees in every weather office.

We met with DNM's director, Mr. Mamadou Lamine Bah, Mr. Boubacar Madina
Diallo, and other functionaries to discuss a work plan. The original
plan included observations in three sites: Conakry, Labe, and Kankan,
but due to the cost and scarcity of materials for gas preparation, the
Labe site was discarded. Also, due to time constraints, we did not
travel to Kankan, but trained DNM personnel who later went to the site,
set up the pilot balloon station and trained additional observers to
help with the soundings. We normally prefer to install the sites
ourselves mainly to ensure that the theodolite is well aligned.
Fortunately, the persons designated to install Kankan were capable and
responsible.

Four observers, including Mr. Camara who also covered many other roles,
attended the training. Mr. Madina Diallo, who speaks good English,
assisted us and greatly facilitated our interaction with the
French-speaking people. Jose Galvez speaks enough French to conduct the
training sessions, but Mr. Diallo helped improve the communication and
allowed Javier Murillo to participate more actively in the training. The
subjects covered included theodolite set up and operation, pilot balloon
soundings, and use of our software to process the data.

The last two days of training were conducted at the radiosonde station.
The theodolite was mounted on the roof of the building using a locally
built tripod. Tracking the balloon from the roof of the two-story
building complicated its release, but this was the best location given
that the building itself and tall trees nearby prevented from tracking
it from the ground. The observers had some problems at first to operate
the theodolite since the design was not familiar to them, but with
practice, they started to feel more comfortable at using it.

In Conakry we witnessed for the first time the process of generating
hydrogen with the GIP-3 generators. It is a rather cumbersome and
potentially dangerous procedure involving mixing and pouring chemicals
and water in a cylinder that has to be sealed quickly after pouring the
water. Safety measures, including the use of protective gear, must be
carefully followed in order to avoid accidents. There exists a
hydrolytic generator at the Conakry site, apparently donated by NOAA,
however it was either not functioning or it could not be operated due to
an intermittent electric supply. We were told that electric power was
only available after 7 PM, but it was not clear for how long it remained
hooked up.

We spent the last day of our visit checking the radiosonde system. We
began by checking the electric generator, which was not operational. It
required replacing the circuit breakers and tightening a few loose
connections. There was also a small mechanical problem that one of the
observers managed to fix. The radiosonde system (a Vaisala Digicora
MW11) was apparently operational although our test launch was
unsuccessful due to a mistake in the baseline procedure. We ran out of
gas unexpectedly and could not make another test, but there were no
reasons to believe that the equipment had any problems. Since August 27,
the Conakry site was able to make at least one radiosonde observation at
12 UTC, though with gaps, until October.

It was apparent soon after our arrival, that the DNM did not have many
resources to support the NAMMA activity and that any expenses related to
the observations had to be covered by NAMMA. These expenses included:
diesel for the electricity generator, radiosondes, balloons, chemicals
for gas, hydrogen generator parts, shipping, customs fees, office
supplies, observer salaries, transportation and other travel expenses
(Kankan site), among others.

[^1]: Acronym for French-led agency, based in Dakar, that oversees
    aviation activities in former French colonies in Africa and
    Madagasgar.

[^2]: "We" here and elsewhere, refers collectively to all of the
    participants in the pilot balloon set-up activity -- the author and
    co-authors of this report.

[^3]: Rosario Douglas, who speaks some French and has extensive field
    experience in supporting PACS-SONET activities in Latin America,
    also accompanied the group.

[^4]: Leaving the airport after our first session, the right rear wheel
    and attached axle shaft fell off our rental vehicle. The driver had
    it fixed, while we continued to the hotel via taxi. The next day,
    coming apart, it had to be fixed again, half-way to Dakar.