Shipboard oceanographic fluorescence lidar development and evaluation based on measurements in Antarctic waters
K. Ohm
Alfred Wegener Institute for Polar and Marine Research,
Marine Physics, Bremerhaven, Germany
R. Reuter, R. Willkomm, H. Harms and M. Stolze
Carl von Ossietzky University, Physics Department,
D-26111 Oldenburg, Germany
Tel: +49 441 - 798, fax: +49 441 - 5 18 70
e-mail: {reuter/willkomm}@las.physik.uni-oldenburg.de
WWW: http.//www.physik.uni-oldenburg.de/docs/las/
The prototype of a shipboard LIDAR for oceanographic applications uses the 355 nm wavelength of a Nd:YAG-Laser to excite fluorescence of yellow substance and chlorophyll, contained in the sea water. The beam attenuation coefficient is derived from the Raman scattered signal. Vertical profiles for the concentration of yellow substance and chlorophyll are derived from time resolved registration of laser induced signals. Continuous measurements of depth profiles have been performed aboard ship with a penetration depth of up to 40 m, depending on detection wavelength and turbidity of the water.
The LIDAR was installed on board RV Polarstern at then end of 1996 during cruise ANT XIV/2 for measurements around the South Shetland Islands and the Drake Passage between South America and the Antarctic Peninsula. Fluorescence data from the lidar are compared to in-situ CTD- and fluorescence measurements. Lidar data from cruise ANT XIV/2 on a meridional track through the Atlantic Ocean from Capetown/South Africa to the North Sea are reported.