Support for Tropical

Atmospheric Research

 

 

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Pilot Study

Campaign aims

The set of instruments that are operational at the Paramaribo site is subject to change because of participation in intensive observational campaigns and because of an increasing involvement of partners. Some instruments require large investments from one or more partners as well as significant additional tasks for the operator team. Feasibility studies and careful preparations are needed before it is decided to install the instruments at a site remote from the home institute.
Under the
STAR project a Pilot Study is conducted in order to assess the feasibility of operating two remote sensing instruments permanently in the tropics: a Fourier Transform InfraRed (FTIR) spectrometer from the University of Bremen (Uni-B) and a Aerosol Raman LIDAR system from the Alfred Wegener Institute of Bremerhaven (AWI-B).

The LIDAR measures aerosol, clouds and water vapor in the troposphere and lower stratosphere. Scientific goals are:
- study tropical biomass burning plumes and Saharan dust events,
- investigate the aerosol distribution and cloud formation processes at the tropical tropopause.

The FTIR measures total columns and vertical concentration profiles of up to 20 trace gases. Scientific goals are:
- study of tropical biomass burning plumes,
- investigate the composition of the tropical tropopause region,
- study the composition of the stratosphere with regard to the stratospheric ozone chemistry.

Observation program

The Pilot Study was conducted in two phases. The first phase was from 25 September - end November 2004, during the long dry season with the ITCZ to the north. This was so successful that it was decided to perform a second phase from 10 February - 18 March 2005, during the short dry period when the ITCZ lies to the south.


instrument containers for the LIDAR (left) and FTIR (right)


LIDAR beam


first LIDAR observation, performed by Franz Immler (AWI-B), shows tropical cirrus at high altitude.
The lower graph indicates the optical depth of the cirrus:

 


first FTIR observation, performed by Tom Weinzierl from Uni-B.
The retrieval shows a carbon monoxide profile over Paramaribo

In synergy with the FTIR and LIDAR observations, daily radiosondes are launched. Specifically for the night-time LIDAR observations and synchronous to ENVISAT satellite overpasses (SCIAMACHY validtion), high accuracy water vapor profiles are recorded with a balloon-launched frost-point hygrometer, called "Snow White".


A SnowWhite hygrometer, along with ozonesonde, launched before dawn

 

Picture gallery

An overview of pictures taken during the pilot study.