Practical Applications of a Space Station (1984) / Chapter Skim
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EARTH'S ENVIRONMENT
EARTH'S ENVIRONMENT
Pages 19-40
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From page 19... ...
As a result of observations from space and other advances, significant progress has been made in our ability to observe and forecast changes in the earth's environment. In preparing this report, the Panel examined the present state of scientific understanding in four major areas of interest -- upper-atmospheric research, global chemical cycles, weather, and climate -- for the purpose of defining requirements for future observational data.
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From page 20... ...
Both dynamic and radiative mechanisms have been identified through which long-term changes in ozone could possibly affect weather patterns of the lower atmosphere -- and hence climate. Thus the study of the stratosphere has taken on a sense of urgency.
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From page 21... ...
Hence arise the need for continuing vigorous effort on three-dimensional models and the challenging requirement to accumulate extensive global data sets, including simultaneous observations of stratospheric structure, motions, and composition. Laboratory Work Required The measurement of key chemical reaction rates and spectroscopic parameters in upper-atmospheric research has progressed well.
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From page 22... ...
Aircraft have provided valuable data on atmospheric dynamics, and in particular on exchange between the stratosphere and the troposphere. Balloon flights and aircraft will continue to be needed as important sources of data for calibrating remote observations and for making detailed measurements that are beyond the present abilities of satellite remote sensors.
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From page 23... ...
However, caution would be required in designing the human interface, since observations of the type described in this section would be quite sensitive to the chemical or particulate contamination and the vibration that would be associated with human presence. Acquisition of the needed long-term global observations of the upper atmosphere may require a low earth orbit that provides limb-scanning coverage at various local times.
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From page 24... ...
Global chemical cycles are closely coupled with the global hydrological cycle. Thus, complete understanding of global chemical cycles requires a corresponding understanding of hydrology as well as of the chemistry of the air and the oceans.
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From page 25... ...
Theoretical studies of global chemical cycles are an essential element of an effective research strategy. Tropospheric photochemical models for instance, have largely been responsible for delineating the central role of free radicals such as OH in the atmospheric chemical systems.
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From page 26... ...
Thus, the Panel recommends that efforts be continued to develop tropospheric remote sensing technology; these efforts should include the use of the Space Shuttle to test each instrument under flight conditions. To calibrate the remote measurements, as well as to monitor those substances that can only be detected by sample analysis, a field measurement program using aircraft and ground-based observation platforms will be needed in conjunction with the development of the remote sensing technology.
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From page 27... ...
Technologies Needed The greatest technological need in the study of tropospheric chemical cycles is the development of remote sensing technology. The current state of the art and likely near-future advances in this technology have been summarized in several recent reports (including Tropospheric Passive Remote Sensing [Keafer, l982]
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From page 28... ...
, the Global Atmospheric Research Program, culminating in the Global Weather Experiment in l979, provided the framework for development and testing of global remote sensing techniques, for improvement of models, and for acquisition of the most advanced computer systems by meteorological research groups and weather
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From page 29... ...
On the nonsynoptic scale -- the mesoscale and storm scale -- there is neither the long history of continuous observations that exists on the synoptic scale, nor the ability to model realistically the complex and nonlinear processes that become more and more important as one moves to progressively smaller scales in the atmosphere. This section discusses the possible roles for space stations or space platforms in producing further improvements in synoptic-scale forecasting and in undertaking the range of activities required to develop a national capability in mesoscale observing and forecasting.
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From page 30... ...
Field Measurements Advancements in field measurements require a composite system that takes advantage of both space-borne and ground-based systems. For example, greatly improved information on mesoscale atmospheric structure will become available through the integration of satellite cloud-type and sounding information with wind and sounding information from ground-based profilers.
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From page 31... ...
For example, a possible observing system might include the following: • Spacecraft in high-inclination (polar) low earth orbit to provide data advanced over that provided by TIROS N (one of the satellites in the National Weather Service operational system)
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From page 32... ...
It seems probable, therefore, that if manned space stations were placed in low earth orbit for other purposes, it would be cost-effective to use the stations to update sensors or other system components, to repair and/or retrieve the payloads, and to construct larger structures for transfer to geostationary orbit. Technologies Needed Currently, in the lowest levels of the atmosphere over land, and in regions of clouds, satellite sounding systems are not able to define the three-dimensional fields of wind, temperature, and humidity with the accuracy desired for numerical weather prediction.
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From page 33... ...
Field Measurements Requirements for field measurements are well defined by the U.S. National Climate Program Plan and by the World
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From page 34... ...
Global data are needed. Regarding oceanic data, in-situ measurements will be needed for subsurface currents, heat flux, salinity, and chemical composition for studies of global geochemical cycles.
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From page 35... ...
The radiation budget and climatological wind and precipitation requirements generate demands for data in the tropical regions and may make a low-inclination orbit useful. For climate, certain satellite measurements (e.g., the Earth Radiation Budget Experiment [ERBE]
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From page 36... ...
Possible Role of a Space Platform or a Space Station in Climate Research and Applications As noted earlier, a climate measurement program requires long-term, stable, and reliable measurements. A space platform implies a long-term effort and thus is consonant with climate objectives.
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From page 37... ...
This will call for the deployment in space of antennas with diameters up to l0 m in low earth orbit, and much larger in geostationary orbit. Role of Man in Space for Climate Research and Applications In general, the Panel finds no requirements for human observers in space for climate research or for
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From page 38... ...
It is generally concluded that a space station offers the potential for several new activities in space, including: Combining a large number of sensors for simultaneous observation of many species in the atmosphere The ability to recalibrate instruments frequently and to use these instruments to intercalibrate satellites The possibility of refurbishing and repairing instruments and of maintaining cooled detectors for an extended period The introduction of new facilities such as lidar or major microwave observatories in space Advances in technology that should be explored are: Development of remote-measurement techniques for OH and N02 Techniques for handling a multiple-data-stream mode, including onboard processing Larger space-borne power systems Development of tropospheric remote sensing instruments Development of a global wind-measuring system Improved microwave radiometry for low-earth-orbit satellites Development of a method for measuring rainfall from satellites Development of a high-spatial-resolution microwave sounding system
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From page 39... ...
1982. The global troposphere: biogeochemical cycles, chemistry, and remote sensing.
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From page 40... ...
l977. Proposed NASA Contribution to the Climate Program.
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