Observing periods and instruments

The AMMA field program aims to provide accurate data to document all the components of the WAM on four interacting spatial scales. Therefore, 26 LOP instruments and 46 EOP instruments, as well as 47 SOP instruments (individual aircraft instruments not inclued) are deployed during the AMMA field campaign. Many instruments are made of several sensors, either co-located or covering a local or meso-site. The number of sensors deployed at the peak of the experiment in 2006 was thus larger than one thousand.

LOP (Long Term Observing Period)    List of instruments up

The Long-term Observing Period (LOP, 2001-2010) is concerned with observations of two types:

• the operational observations covering the regional scale and
• additional observations on the mesoscale and local sites.

The objective is to document and analyse the interannual variability of some components of the WAM which have characteristic long time scales (sea surface temperature and salinity, ground water balance, vegetation dynamics, anthropogenic forcing).

EOP (Enhanced Observing Period)    List of instruments up

The Enhanced Observing Period (EOP) is designed to provide a detailed documentation of the annual cycle of the surface and atmospheric parameters on convective to regional scales. The regional coverage is obtained through various actions including a restoration and upgrade of the operational networks, and the installation of specific new instruments deployed in networks. Added to this continental deployment are oceanic measurements carried out by a research vessel during two annual cruises.

SOP (Special Observing Period)    List of instruments up

The Special Observing Period, in 2006, focused on the study of specific processes and weather systems at various key stages of the annual cycle of the WAM, with intensified observations occurring over the following periods:

1. the dry season (SOP0; 10 January - 20 February);
2. Monsoon onset (SOP1; 15 May to 30 June);
3. Peak monsoon (SOP2; 1 July to 30 August);
4. Late monsoon, defined here as the period when the downstream impact of the WAM onto the formation of cyclones over the tropical Atlantic is at its peak (SOP3; 15 August to 30 September).