Recent Satellite Studies
17
of 5 days is selected and a picture composed of the minimum values is printed. Cloud-free
land or ocean is much less reflective than ice, snow and clouds, so this process retains as
bright areas only those which represent slowly-changing fields of ice and snow or those
few areas of bright cloud which may persist throughout the period. Minimum brightness
composites are prepared and issued as routine from the National Environmental Satellite
Service, Suitland, U.S.A.
Chlorophyll has been measured at sea from low-flying aircraft equipped with spectrometers (CLARKE, EWING and LORENZEN, 1970). The planned installation of a spectrometer
for measurement of chlorophyll in an Earth Resources Technology Satellite will make it
possible to investigate the dynamics of plankton populations in upwelling areas.
IV. Concluding Remarks
There are 3 ways in which satellites can be of use to marine biologists: 1. by the direct
observation of quantities of immediate interest such as sea temperature and chlorophyll
distribution; 2. by permitting important advances to be made in physical sciences,
meteorology and physical oceanography, with which the marine biologist inevitably
becomes involved; and 3. as a communications agent. An indication of the possibilities
for the use of satellite sensors has been given in the above account. The third use of
satellites as a communications aid should also be mentioned. They can be used to receive,
record and retransmit signals broadcast from automatic sensing apparatus at the ocean
surface or in the atmosphere. The apparatus may be mounted on anchored or drifting
observing platforms or on submersible vehicles. Transmitters attached to marine organisms which visit the ocean surface might be used as tracers.
Observations made by United States satellites are made available, usually at the cost
of reproduction, from two agencies: National Weather Records Center, NOAA, Asheville, N.C., U.S.A.; and National Space Science Data Center, Goddard Space Flight
Center, Code 601, Greenbelt, Maryland 20771, U.S.A. A useful first guide to what is
available is given in the ESSA Technical Report NESC 53 which can be obtained from
the Clearinghouse for Federal Scientific and Technical Information, U.S. Dept. of
Commerce, Sills Building, 5285 Port Royal Road, Springfield, Va. 22151.
17
of 5 days is selected and a picture composed of the minimum values is printed. Cloud-free
land or ocean is much less reflective than ice, snow and clouds, so this process retains as
bright areas only those which represent slowly-changing fields of ice and snow or those
few areas of bright cloud which may persist throughout the period. Minimum brightness
composites are prepared and issued as routine from the National Environmental Satellite
Service, Suitland, U.S.A.
Chlorophyll has been measured at sea from low-flying aircraft equipped with spectrometers (CLARKE, EWING and LORENZEN, 1970). The planned installation of a spectrometer
for measurement of chlorophyll in an Earth Resources Technology Satellite will make it
possible to investigate the dynamics of plankton populations in upwelling areas.
IV. Concluding Remarks
There are 3 ways in which satellites can be of use to marine biologists: 1. by the direct
observation of quantities of immediate interest such as sea temperature and chlorophyll
distribution; 2. by permitting important advances to be made in physical sciences,
meteorology and physical oceanography, with which the marine biologist inevitably
becomes involved; and 3. as a communications agent. An indication of the possibilities
for the use of satellite sensors has been given in the above account. The third use of
satellites as a communications aid should also be mentioned. They can be used to receive,
record and retransmit signals broadcast from automatic sensing apparatus at the ocean
surface or in the atmosphere. The apparatus may be mounted on anchored or drifting
observing platforms or on submersible vehicles. Transmitters attached to marine organisms which visit the ocean surface might be used as tracers.
Observations made by United States satellites are made available, usually at the cost
of reproduction, from two agencies: National Weather Records Center, NOAA, Asheville, N.C., U.S.A.; and National Space Science Data Center, Goddard Space Flight
Center, Code 601, Greenbelt, Maryland 20771, U.S.A. A useful first guide to what is
available is given in the ESSA Technical Report NESC 53 which can be obtained from
the Clearinghouse for Federal Scientific and Technical Information, U.S. Dept. of
Commerce, Sills Building, 5285 Port Royal Road, Springfield, Va. 22151.