Studies of the Tropical Atmosphere: Towards a high altitude atmospheric observatory at Mérida
Abstract:AWI is a research center that operates research stations both in Antarctica and in the Arctic. In addition mobile research platforms like research vessels and research aircrafts are at AWIs command. At all these research platforms atmospheric investigations play a key role. Studying the development of the Antarctic ozone hole by regular ozone soundings is just one example of the various kinds of studies being performed. Since many years atmospheric investigations are also carried out in the tropics with AWIs research vessel Polarstern by using mobile instruments which are installed aboard the ship in laboratory containers.Currently, a set of AWIs mobile instruments is being operated at a tropical site, namely the Meteorological Observatory in Paramaribo (Suriname) taking part in the international measurement campaign STAR. The tropics are particularly interesting for atmospheric research since the chemical composition of the global atmosphere is to a large extent determined by tropical processes, as the air from both hemispheres converges here, undergoes chemical transformations and ascends to higher altitudes after which it flows back pole ward. The tropical tropopause is a region of great importance for the stratospheric composition, since the bulk of tropospheric air enters the stratosphere through the tropical tropopause. Furthermore, the bulk of stratospheric ozone is produced in the tropics.Thus, there is a necessity to establish atmospheric observatories in the tropics which could be part of global atmospheric networks like NDSC, the Network for Detection of Stratospheric Change, GAW (Global Atmospheric Watch) and UV radiation networks. Since many years AWI and other research institutes along with the Universidad de los Andes (ULA) and the Centro de Investigaciones de Astronomia Francisco J. Duarte (CIDA) have planned to set-up a high altitude tropical atmospheric observatory at Méridas surrounding mountains. AWI planned to install instruments at the Observatorio Nacional de Llano del Hato at an altitude of 3600 m. The instruments which will hopefully be colocated there in the near future include an Aerosol Raman Lidar (for detection of aerosols, cirrus clouds and water vapour), a FTIR spectrometer (for measurements of atmospheric trace gases), a sun photometer (for determination of the optical thickness of the atmosphere), a sky imager (for recording the cloud coverage) and a UV spectral radiometer (to register the solar UV spectral irradiance). The collocation of the various instruments in the Mérida area will provide a synergy of the measurements that will improve the interpretation and retrieval of the observations.In summary it can be stated that the prime objective is to set-up international atmospheric observation systems in Mérida, and to support cooperation between Venezuelan and European institutes and to ensure the future execution of long-term observational programmes as well as to raise public awareness for climate change issues. It is planned to promote the construction of long, homogenized time series of climate and other global change parameters in the tropics In order to achieve this, it is also intended to establish an exchange programme for students and staff.
Helmholtz Research Programs > MARCOPOLI (2004-2008) > POL1-Processes and interactions in the polar climate system