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From page 62... ...
If we are to react rationally to the inevitable climatic changes of the future, and if we are ever to predict their future course, whether they are natural or man-induced, a far greater understanding of these changes is required than we now possess. It is, moreover, important that this knowledge be acquired as soon as possible.
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From page 63... ...
What Climatic Events and Processes Can We Now Identify? From the analysis of accumulated instrumental climatic data, we can identify some of the major characteristics of the climatic changes of the past few decades.
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From page 64... ...
These and other models are just beginning to identify the energetic mesoscale eddy, which in some ways appears to be the oceanic counterpart of the transient cyclones and anticyclones in the atmosphere. From the analysis of a variety of climate models, as well as from the analysis of climatic data, we can identify a number of links or processes in the phenomenon of climatic change.
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From page 65... ...
What we cannot identify at the present time is how the complete climatic system operates, which are its most critical and sensitive parts, which processes are responsible for its changes, and what are the most likely future climates. In short, while we know something about climate itself, we know very little about climatic change.
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From page 66... ...
THE RESEARCH PROGRAM (NCRP) We have here assembled our specific recommendations for the data, the research, and the applications that we believe constitute the needed elements of a comprehensive national research program on climatic change.
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From page 67... ...
These are the efforts that we believe to be necessary to make the store of climatic data more useful to the climatic research community and to ensure the systematic collection of the needed climatic data in the future. Climatic Data Analysis Instrumental Data Instrumental observations of the atmosphere adequate to depict even a decadal climatic variation are available only for about the last half century for selected regions of the northern hemisphere, and the observational coverage of the oceans is even poorer in both space and time (see Appendix A)
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From page 68... ...
Once such syntheses are available, we recommend that suitable climatological diagnostic. studies be made using dynamical climate models to generate systematically the various auxiliary and unobserved climatic variables, such as evaporation, sensible heat flux, surface wind stress, and the balances of surface heat, moisture, and momentum.
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From page 69... ...
Proxy Data We recognize the unique value of proxy data for studies of climatic change. Such data are obtained from the analysis of tree-ring growth patterns, glacier movements, lake and deep-sea sediments, ice cores, and studies of soil and periglacial stratigraphy.
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From page 70... ...
Special efforts should be made to calibrate the few millenia-long treering records with information from other suitable proxy data sources, such as pollen, varves, and ice cores. Studies of pollen records in lakes and bogs should be extended.
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From page 71... ...
Additional data should be obtained on the fluctuations in the extent and volume of the polar ice sheets during this time interval. Particular attention should be given to the smaller ice sheets, such as the West Antarctic and Greenland ice sheets, which react more rapidly to climatic variations.
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From page 72... ...
Climatic Index Identification and Monitoring In addition to the data provided by conventional surface and upper-air observations, climatic studies require other contemporary data that are not now readily available. The one hope for obtaining truly global coverage of many current climatic variables rests with satellite observations.
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From page 73... ...
Monitor the latent heat released in large-scale tropical convection, possibly with the aid of satellite cloud observations. Develop methods to monitor remotely the surface latent heat flux into the atmosphere, possibly with the aid of satellite measurements of the vertical distribution and total amount of water vapor.
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From page 74... ...
Monitor the distribution of surface wind over the oceans, possibly by radar measurements of the scattering by surface waves or from the microwave emissivity changes created by foam. Oceanic Indices In view of the fundamental role the oceans play in the processes of climatic change, special efforts should be made to monitor those oceanic variables associated with large-scale thermal interaction with the atmosphere.
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From page 75... ...
Cryospheric Indices In view of the great influence of snow and ice cover on the surface energy balance, further efforts should be made to Monitor the distribution of sea ice in the polar oceans and the ice in major lakes and estuaries. Efforts should also be made to measure as many as possible of the ice's physical properties by remote sensing.
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From page 76... ...
Monitor the extent, depth, and characteristics of worldwide snow cover. Surface and Hydrologic Indices In association with the monitoring of the elements of the surface heat balance, and of the various oceanic and cryospheric climatic indices, initially lower priority but nevertheless important efforts should be made to Monitor the natural changes of surface vegetative cover, possibly by observations from earth resources satellites.
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From page 77... ...
As noted below, these efforts should be coordinated on an international scale and be a part of an international climatic program. Research Needed on Climatic Variation We here outline the research that we believe needs to be performed, in terms of model development, theoretical research, and empirical and diagnostic studies.
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From page 78... ...
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From page 79... ...
"(Sased QWIOS UL [epeoap Ajqissod 30) Apiwak ‘A ‘AyTeuoswes ‘g ‘ATYyUOU "WH ‘(sesed suios ut Ajjep Ajqissod JO)
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From page 80... ...
climatic change must be given further theoretical attention. While the local details of weather do not appear to be predictable beyond a few weeks' time, the consequences of this fact for climatic variations are not clear.
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From page 81... ...
, the average global climate simulated by such models shows a reasonable resemblance to observation; several examples of such simulations are shown in Appendix B In order to improve the fidelity of such global atmospheric models for the simulation of the various processes of climatic change, and to ensure their increased availability for the conduct of climatic experiments, efforts should be made to Improve the models' treatment of clouds, especially those of the nonprecipitating high-altitude cirrus and the low-level stratus type.
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From page 82... ...
Oceanic General Circulation Models The oceanic general circulation models (or GCM's) are generally at a less advanced stage of development than their atmospheric counterparts and have only recently been extended to the global ocean (see Appendix B)
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From page 83... ...
Improve the prediction of sea-surface temperature and heat transport by the inclusion of the depth and structure of the surface mixed layer as a predicted variable in oceanic general circulation models. This should include experiments on the numerical forecasting of the oceanic surface layer, as driven by observed surface conditions, and the formation and behavior of pools of anomalously warm or cold water.
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From page 84... ...
The presence of lateral boundaries and the need to resolve mesoscale motions may make alternative numerical methods of particular use in numerical ocean models. Coupled Global Atmosphere -- Ocean Models Tests of climatic change extending over one or more years are not adequate unless they are made with a model of the coupled ocean -- atmosphere system.
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From page 85... ...
Although not a research task in itself, special efforts should be made to appropriately store, analyze, and display the rather staggering amounts of data generated during the integration of CGCM's, so that subsequent diagnosis can be performed efficiently. Statistical-Dynamical Climate Models Although the coupled numerical models of the global circulation offer the most comprehensive and detailed solutions available, even with the fastest computers envisaged relatively few century-long climatic simulations will be possible, and it is likely that none will be performed for periods as long as a millenium.
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From page 86... ...
While such models provide less resolution of the details of climatic change, they may display less climatic noise than do the global circulation models. In order to ensure the availability of the hierarchy of models needed in a comprehensive research program on climatic change, the following research should be carried out: Statistical-dynamical models of the coupled time-dependent atmospheric and oceanic circulation should be constructed and calibrated that embody suitable time- and space-averaged representations of the climatic elements.
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From page 87... ...
Empirical and Diagnostic Studies of Climatic Variation Although we have recommended some diagnostic and empirical studies in connection with the analysis of instrumental and proxy climatic data, such studies should also be made on a phenomenological basis as part of the climatic analysis and research program. As the record of past climates is made more complete, there will be increased opportunity to carry out such investigations with both instrumental and proxy data.
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From page 88... ...
Compared with this longperiod panorama, instrumental observations provide a frustratingly short record. It is at this juncture that the intersection of paleoclimatic and numerical modeling studies offers the most promise: the global climatic models have the potential ability to simulate at least a near-equilibrium approximation to past climates subject to the appropriate geological boundary conditions, while the paleoclimatic records can be used as verification data.
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From page 89... ...
For this application the dynamics of ice sheets should be incorporated into the coupled ocean -- atmosphere models and note taken of the possible time dependence of the remaining boundary conditions, such as solar radiation and continental drift. In particular, the astronomical changes of seasonal radiation resulting from the variation of the earth's orbital parameters should be incorporated in a climate model, and the resulting simulated climatic changes compared with the paleoclimatic evidence.
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From page 90... ...
: The changes of incoming solar radiation. These experiments should be performed with coupled models, in view of the dominance of the oceans in the planetary heat storage, and should include changes in both the amount and spectral distribution of solar radiation.
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From page 91... ...
This, together with the knowledge gained from the observational and research portions of the program outlined above, will lay the scientific foundation for what might be called climatic engineering. Development of Long-Range or Climatic Forecasting A third important area of application of climatic studies is the problem of long-range or climatic forecasting on time scales of months, seasons, and years.
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From page 92... ...
Systematic empirical and diagnostic studies of longer-period variations in the climatic system should be undertaken with the aid of models and the expanding data base of monitored variables. Assessment of Climate's Impact on Man While the above efforts are concerned with the physical aspects of the problem of climatic variation, a climatic research program should also include studies of the impact of climate and climatic change on man himself; this is best done with the guidance and insight provided by climate models.
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From page 93... ...
The systematic assembly of worldwide data on the production and use of energy and the determination of its response and sensitivity to climatic variations. As in the cases of food and water, simulation models should be constructed, so that the consequences of various patterns of hypothetical climatic change can be estimated.
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From page 94... ...
be established as a subprogram of the NcRP. The purposes of this subprogram are to facilitate the exchange of data and information among the various climatic data depositories and research projects and to support the coordinated preparation, analysis, and dissemination of appropriate climatic statistics.
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From page 95... ...
and Climatic Index Monitoring Program (CIMP) , we recommend the development of new climatic data-analysis facilities at appropriate locations, including linkage to the various specialized data centers and climatic monitoring agencies by a high-speed data-transmission network.
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From page 96... ...
These include the various Quaternary research groups, geological and oceanographic laboratories, numerical modeling groups, and polar studies and environmental institutes. Each of these efforts makes a contribution to the national climatic research picture, and they represent a valuable reservoir of experience
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From page 97... ...
Although it is difficult to make precise projections, the volume of data processing involved in the analysis and monitoring portions of the program alone indicate that a dedicated machine of at least the cpc 7600 class is required for the implementation of the cDAP and cimp. The computer needs of the research consortia and of the other research groups involved in the modeling portions of the program are even more demanding, in view of the variety of the needed climatic models and tests and the number and the length of the necessary climatic simulation experiments
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From page 98... ...
TABLE 6.2 Estimated Computing Needs for the National Climatic Research Program * Present Use ° Projected Use ° Climatic data analysis and monitoring 0.2 1.54 Atmospheric GcM development 0.8 ° 3.0 Oceanic GCM development 0.2 2.0 Coupled Gcm's (climate models)
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From page 99... ...
(c.1980) Climatic data assembly and analysis 5 18 Climatic index monitoring ° 4 12 Climatic modeling and applications 9 37 18 67 *
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From page 100... ...
FIGURE 6.1 Projected costs of the National Climatic Research Program (NCRP)
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From page 101... ...
The extent to which elements of the recommended cCDAP and cIMP subprograms of the NCRP may be considered as add-ons to such existing programs needs further consideration, as does the extent to which the future costs of GARP itself may be merged with those envisaged for the NCRP. Also in need of further study are the United States' contributions to the costs of the various subprograms recommended as part of the International Climatic Research Program (icRP)
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From page 102... ...
(1976-1980) Climatic data 1.
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From page 103... ...
The long-range goals and full-scale operation of the NCRP in the period beyond 1980 are portrayed in the upper part of Figure 6.2. During this period, the full interaction among the observational, analysis, modeling, and theoretical components of the program will occur, leading to the development of an operational global climatic data system and, it is hoped, to the acquisition of an increasingly accurate theory of climatic variation.
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From page 104... ...
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From page 105... ...
Both the short-term and long-term goals of the NCRP are also shared by the International Climatic Research Program (ICRP) recommended below.
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From page 106... ...
For climatic change purposes, on the other hand, such numerical models must include the changes of the oceanic heat storage. Such a slowly varying feature may be regarded as a boundary or external condition for weather prediction but becomes an internal part of the system for climatic variation.
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From page 107... ...
is sketched in the lower part of Figure 6:2, and the program's scientific elements are discussed in more detail below. Program Elements Climatic Data Analysis The main thrust of the international climatic program should be the collection and analysis of climatic data during the Icp's, 1980-2000.
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From page 108... ...
We therefore recommend that the IcrP include the following: International cooperative programs to assess the impacts of observed climatic changes on the economies of the world's nations, including
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From page 109... ...
It seems clear, however, that an appropriate balance of effort should be maintained among ICRP, the various national climatic research programs, and other international programs such as the World Weather Watch (www) and the United Nations Environment Program (UNEP)
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From page 111... ...
L Mobley, 1974: Updated global monthly mean ocean surface temperatures, R- -- 1310-arpa, The Rand Corporation, Santa Monica, Calif.
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From page 112... ...
A., 1974: Perspectives on climatic change (to be published in Science)
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From page 113... ...
C Langway, Jr., 1971: Cli matic record revealed by the Camp Century ice core, in The Late Cenozoic Glacial Ages, K
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From page 114... ...
H., and W Karlén, 1973: Holocene climatic changes, their pattern and possible cause, Quaternary Res., 3:155- -- 205.
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From page 115... ...
D Hays, 1974: The eastern equatorial Atlantic: sea-surface temperature and circulation response to global climatic change during the past 200,000 years, Geol.
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From page 116... ...
Mathieu, 1971: The late Ceno zoic history of the Arctic Ocean, in The Late Cenozoic Glacial Ages, K Ture kian, ed., Yale U
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From page 117... ...
B., 1974: Late Quaternary climatic changes in the Norwegian and Greenland seas, in Proc. 24th Alaskan Sci.
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From page 118... ...
Landsberg, H E., 1970: Man-made climatic changes, Science, 170:1265 -- 1274.
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From page 119... ...
N., 1970: Climatic change as a mathematical problem, J
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From page 120... ...
L Thurber, 1969: The astronomic theory of climatic change: Barbados data, J
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From page 121... ...
C., Jr., 1973: Late Pleistocene- -- Holocene oceanographic changes in the northeastern Pacific, Quaternary Res., 3:99 -- 109.
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From page 122... ...
B., 1972: How important are climatic changes? Weather, 27:262 -- 271.
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From page 123... ...
M., 1973: North Pacific radiolarian assemblages and their relationship to oceanographic parameters, Quaternary Res., 3:73-88. Saltzman, B., 1973: Parameterizations of hemispheric heating and temperature variance fields in the lower troposphere, Pure Appl.
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From page 124... ...
H., 1973: The effect of large-scale eddies on climatic change, J Atmos.
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From page 125... ...
A Bryson, 1972: Late- and post-glacial climatic change in the northern midwest, USA: quantitative estimates derived from fossil pollen spectra by multivariate statistical analysis, Quaternary Res., 2:70-115.
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From page 126... ...
Wright, H E., Jr., 1971: Lake Quaternary vegetational history of North America, in The Late Cenozoic Glacial Ages, K
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