CBS/OPAG-IOS/ET-EGOS-4/Doc. 5.4 - WMO

WORLD METEOROLOGICAL ORGANIZATION
______________ COMMISSION FOR BASIC SYSTEMS
OPEN PROGRAMME AREA GROUP ON
INTEGRATED OBSERVING SYSTEMS EXPERT TEAM ON EVOLUTION OF THE
GLOBAL OBSERVING SYSTEM
Fourth Session GENEVA, SWITZERLAND, 7-11 JULY 2008
| |CBS/OPAG-IOS/ET-EGOS-4/Doc. 5.3
(23.VI.2008)
______
ITEM: 5.3
Original: ENGLISH
| |
Review of other Activities Related to the ET-EGOS and OPAG-IOS AMMA Activities (Submitted by Mr Jean-Blaise Ngamini, ASECNA) | |
|Summary and Purpose of Document |
| |
|This document provides information on the radiosounding program |
|of the African Monsoon Multidisciplinary Analysis (AMMA), and in |
|particular on its management, infrastructure and communications |
|aspects, on the AMMA intensive sounding programme, and new |
|development in the AMMA network in 2007. |
ACTION PROPOSED The Meeting is invited to note the information contained in this
document for discussion under the appropriate agenda items. ____________
[pic] Analyse Multidisciplinaire de la Mousson Africaine
African Monsoon Multidisciplinary Analysis
Report to the WMO / CBS on the AMMA radiosounding programme AMMA Task Team (TT1) in charge of soundings 18 June 2008
Radiosounding Performances received at ASECNA head quarter in 2007
[pic]
Summary In recent years, the meteorological observing system in Africa has
been in a worse state than that of any other populated continent. The
declining observational network and the ongoing communication problems of
West Africa are two of the major challenges for the monitoring and
prediction of weather and climate, and for the establishment of early
warning systems in the region. These realities motivated the African
Monsoon Multidisciplinary Analysis (AMMA*; Redelsperger, et al., 2006), and
placed a high priority on improving the upper air stations as part of
AMMA's multi-year field experiment. Since 2004, AMMA scientists have been working with operational
agencies in Africa to reactivate silent radiosonde stations, to renovate
unreliable stations, and to install new stations in regions of particular
climatic importance. At the time of writing, 21 stations are active over
West Africa (see Figure 1), and during the period of June to September
2006, some 7,000 soundings were made, representing the greatest density of
radiosondes ever launched in the region; greater even than during GATE in
1974. An important goal of AMMA is to evaluate the impact of these data on
weather and climate prediction for West Africa, and for the hurricane
genesis regions of the tropical Atlantic.
A number of new atmospheric profiling systems are being used in West
Africa, including UHF wind profilers, AMDARs and satellite products.
However, for operational purposes, for an intensive observational program
and for long-term climate monitoring there is currently no alternative to
the radiosonde to provide comprehensive vertical profiles of winds and
thermodynamics in the troposphere. This report confirms some strong statements regarding upper-air
operations in the region we made last year: I. Stations which have good infrastructure and are supplied with
consumables can all achieve 95% success or better. Therefore,
we confirm that the primary problems on the network are supply
of consumables and communications; II. Ensuring the reliability of the network has been, and will
continue to be a major management task (typically requiring 6-12
months of management time per year).
The work involves planning of supplies and communications, as
well as responsiveness to technical problems; III. The overall success rate for 2006, relative to our plans, was
54% (ECMWF), 52% (NCEP) and 47% (GTS - estimated).
Significantly, most of the data lost to the wider GTS were from
the 4 new stations. For the stations which existed before AMMA,
the success rate improved from 64% (2005) to 73% (March -
December 2006; NCEP).
In 2007, average success across the network has been better than
80%; and, IV. If we compare the percentage of data received at the ECMWF and
the reports we received from the stations, we can conclude that
the transmission problem is not completely solved in the region. Overall, we regard AMMA as having been successful in implementing its
upper-air programme because it had a clear strategy and a set of priorities
which enabled the project to deal promptly with problems in infrastructure
and consumables. We therefore wish to recommend the establishment of a long-term
management group for the upper-air network in West Africa, involving, as it
has done for AMMA, specialists from data-using as well as data-collecting
agencies.
Management of the 'AMMA' radiosonde programme In order to balance the different scientific and operational
objectives of the AMMA radiosonde programme, a management group was set up
- the so-called 'Task Team 1' (TT1), bringing together research scientists,
operational agencies in Africa making the soundings, and operational
centres in Europe and the United States of America, whose models assimilate
the data. The largest organisation managing operational soundings in West
Africa is ASECNA - a multinational agency operating in 17 countries.
Working with ASECNA has provided a single management point for 12 African
nations involved in AMMA; however, each of these nations also has its own
NMS, whose relationship with ASECNA is often complex. The AMMA also works
closely with NIMET, GMET, the DMN of Guinea and the Algerian ONM. Among
its members, the TT1 includes two members of the GUAN program. TT1 was able to deal with some long-standing difficulties in the
meteorological observing network through the following means: . Through the involvement of many Anglophone and francophone
partners, and a significant number of bilingual (and multi-
lingual) participants, various cooperative actions were carried
out between English-speaking and French-speaking countries; . Through the deep involvement of ASECNA in the programme, and
with ASECNA's considerable capacity in skills and training,
solutions to many problems could be carried out without non-
African intervention, thereby building local capacity; and, . To overcome the difficulties associated with the communication
on management matters, AMMA appointed 'monitors' for each
station in the network. These monitors were volunteers from
among the scientific community, with an interest in the station
for their own scientific purposes, or through fieldwork at
neighbouring sites. The monitors were able to communicate
regularly by telephone with the Chef de Station (typically
monthly - also at short notice when needed), to liaise over
issues of data transmission, supply of consumables, staffing,
changes in the operational plans and so on. The fact that 10
different monitors were engaged in the network, working with
Anglophone or francophone stations, points to the magnitude of
the management burden required to keep the network running
smoothly. The area of staff training is one in which ASECNA enjoys real
advantages, through its economies of scale: by combining the income due to
meteorological activities in several countries, ASECNA can afford to
operate a meteorological training school at Niamey (EAMAC), as well as a
meteorological laboratory at its Headquarters in Dakar. Together, these
institutions hold long-term skills and capacity in experimentation,
training and repairs. With financial budgets always being tight, such
capacity is difficult to sustain in West African countries outside the
ASECNA group. For instance, there were many examples of visits of staff
between ASECNA and non-ASECNA agencies, to solve technical problems or to
share training exercises. Bulk ordering of consumables was carried out by
ASECNA, on behalf of several funded science programs in AMMA, and several
operational centres in Africa (including the non-ASECNA countries of
Algeria, Ghana, Guinea and Nigeria), leading to considerable savings in the
prices. Infrastructure Through scientific funding for AMMA, major investment has been made
in the infrastructure in the region, including provision of buildings,
ground stations, communications, gas-making facilities and staff training. The expenditure on infrastructure was strongly affected by Vaisala's
phase-out of the RS80 sonde, and the consequent need to replace many ground
stations, and upgrade others.
The monopoly situation meant that costs were beyond