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La Jolla, CA 92038-0271
NODC completes move to NOAA Silver Spring complex
As part of NOAA's consolidation effort, the National Oceanographic Data Center (NODC) completed its relocation to the NOAA Silver Spring Metro Center complex this January. All data and information requests should now be directed to NODC's User Services group at: National Oceanographic Data Center NOAA/NESDIS E/OC1 SSMC3, 4th Floor 1315 East-West Highway Silver Spring, MD 20910-3282 Phone: 301-713-3277 or -3278 Fax: 301-713-3302 E-mail: firstname.lastname@example.org
1996, at Epcot Science and Technology, Lake Buena Vista, Florida.
Conference topics include: environmental information management and decision support systems, resource management, pollution monitoring and control, legislation, regulation and compliance, and new and future environmental applications, issues, and developments. Interested contributors should submit a proposal form with a 250-word summary on or before April 1, 1996. More information can be obtained from: ERIM/Eco-Informa P.O. Box 134001 Ann Arbor, MI 48113-4001 Phone: 313-994-1200 ext. 3234 Fax: 313-994-5123 E-mail: email@example.com Internet: http://www.erim.org/CONF/ conf.html
Davidson to direct newly renamed Coastal Services Center
Margaret A. Davidson has been named Director of NOAA's Coastal Services Center (CSC) in Charleston, South Carolina, which was formerly the Center for Coastal Ecosystem Health (CCEH.) Davidson has worked with the South Carolina Sea Grant Consortium for the past 15 years and has served as the executive director since 1983. She also holds a faculty appointment at the University of Charleston and serves on the adjunct faculties of Clemson University and the University of South Carolina.
The CSC was established by NOAA in 1994 at the Charleston Navy Base. The recent name change better reflects the emphasis the CSC is placing on functioning as a service provider to the coastal management community. The Center is dedicated to linking those living and working in the coastal environment to the information and technology that can help them make informed decisions and better integrate environmental and economic considerations. The CSC WWW site can be accessed at URL: http://www.csc.noaa.gov.
NGDC scientists participate in NSF paleoclimate workshop
National Geophysical Data Center (NGDC) paleoclimatologists Jonathan Overpeck and Robert Webb attended the National Science Foundation (NSF) Paleoclimates of Arctic Lakes and Estuaries (PALE) Principal Investigators Workshop on February 11-13, 1996 at Boulder, Colorado. The workshop focussed on synthesizing available evidence for environmental change across Beringia and the northwestern Atlantic, in order to evaluate whether coherent spatial and temporal variations exist.
Dr. Overpeck led the working group on "Climate variability of the last 1000 years.” The goal of this group is to produce a high-profile scientific paper summarizing the state-of-the-art understanding of Arctic climate change leading to this century. Paleoclimatic data already show that one of the most dramatic circum-Arctic warmings on record took place between 1850 and 1920 (before the period of widespread instrumental coverage in this region.) This end of the "Little Ice Age" must have begun as a naturallyforced change, but may have been accelerated by anthropogenic (trace-gas) forcing in this century.
IWC holds symposium on the effect of climate change on cetaceans
NOAA's National Marine Fisheries Service, Southwest Fisheries Science Center is hosting the International Whaling Commission (IWC) Symposium on the Effects of Climate Change on Cetaceans on March 25-26, 1996. This is the second in a series of meetings convened by the IWC on the potential environmental effects on cetacean populations. The symposium will focus on the processes related to global climate change and how these processes may effect cetacean populations. It will also address current views on what changes have been detected and are most likely to occur, followed by a consideration of what trophic or direct processes would link these changes to the distribution and abundance of cetaceans.
The deadline for registration and fees is March 1, 1996, or as space permits. A workshop which will be limited to 35 participants will follow on March 27-30, 1996, with preference given to symposium speakers and scientists active in relevant fields. For more information, contact Dr. Stephen B. Reilly, Chairman, IWC Scientific Committee via e-mail at: steve@caliban. ucsd.edu or contact: Joyce Sisson NOAA/NMES Southwest Fisheries Science Center P.O. Box 271
Eco-Informa '96 announcement and call for papers
Eco-Informa '96 is the fourth major international conference in a unique series that focuses on worldwide communications for environmental applications. The comprehensive multidisciplinary forum is designed to foster the interaction and exchange of global environmental technology between scientific, governmental, and commercial communities. EcoInforma '96 will be held for the first time in the United States from November 4-7,
Fourth POES Users' Symposium
NOAA's Polar-orbiting Operational Satellite (POES), the current series of TIROS satellites, is the third generation polar-orbiting spacecraft system operated by NOAA. Circling the Earth in sun-synchronous orbit, these satellites support large-scale, long-range weather forecasts and numerous secondary missions.
The themes of the Fourth POES Users' Symposium are to inform users of current and future plans of U.S. and international polar satellite systems, and to discuss the changes taking place with NOAA's newest series of polar-orbiting satellites (NOAA-K, L, and M.)
The symposium will be held in Annapolis, MD, from June 10-12, 1996. For registration or exhibit information, contact: Phone: 301-345-2000, ext. 135 or 120 Fax: 301-441-1771 E-mail: firstname.lastname@example.org Internet: http://infrmtcs.com/-poesuser/
SPIDR, from page 2
wide satellite coverage (Figure 3). The button tool allows users to “fly" one of four DMSP satellites about the globe (Figure 4.)
DMSP satellite imagery
Defense Meteorological Satellite Program (DMSP) polar orbiting satellites collect visible and thermal infrared imagery in global coverage along a 3000km-wide swath with the Operational Linescan System (OLS). Internet users may select imagery by date and geographical position anywhere on the Earth. DMSP visible and infrared images are returned along with a map of the satellite path and a button tool for navigating through the database of world
lonospheric vertical sounding database
Users can plot ionospheric vertical sounding data from four full solar cycles of data (1950 through 1996) from a global network of up to 101 different ionosonde stations, including near-realtime data from the NOAA Space Environment Laboratory Data Acquisition and Display System (SELDADS). The Web user chooses the month and year
from the pull-down menus. An "on the fly" map is generated
with the stations containing data for the period selected. The user clicks the map in the region of interest and the closest station with data available is automatically plotted (Figure 5.) Currently maximum electron density (foF2) plots are generated with monthly medians plotted as a red line overlaying the daily values. Other scaled and derived parameters including the true height of maximum density (hmF2) are planned for future SPIDR developments.
Digital data from ionosonde stations around the world are added to the SPIDR database as they are received, processed, and passed through quality control filters. Each month NGDC receives near-real-time data from the SELDADS network for the previous month and places them in the SPIDR database tagged as preliminary data. The Internet user may also choose to generate a Worldwide Contour Plot computed from the lonospheric conductivity and Electron Density (ICED) global model of the ionosphere. The user completes the selection form and SPIDR then displays a color contour map of maximum electron density (foF2) based on month and sunspot number.
Geomagnetic variations database
Geomagnetic one minute variations data for 1990 through 1996 from up to 61 observatories worldwide reside in a database management system. Users can interactively search the database for the date and location of interest. Geomag
A Figure 5. Ionospheric maximum electron density data plot for Boulder during the February 1986 storm. The gray line indicates median values for the month. Users can select from four solar cycles of ionospheric data by global location.
Herb Kroehl, Division Chief
Craig Clark, Data Manager
netic one minute variation data are se- tool. Input from scientists and other lected, plotted, and distributed over the users around the globe has and will conWeb (Figure 6.) The effect of geomag- tinue to shape the development of the netic activity on the aurora can be SPIDR system. The needs of both exterquickly accessed through links to the nal and NGDC users set the priorities DMSP browse imagery (Figure 7.)
for SPIDR, with the goal being to satisfy Digital hourly values dating back to both external and internal users 1902 from 223 different geomagnetic through a single interface. observatories will be loaded into the
In addition to future developments SPIDR system in the future. Planned mentioned above, projects in the immealso is the ability to create plots for mul- diate future include: data delivery for tiple observatories stacked one above SPIDR datasets, the addition of SSM/I the other for comparison. Geomagnetic (microwave imager) data from DMSP, indices Ap and Kp are available on stack plots of solar indices such as sunSPIDR as well.
spot number and 10.7 cm flux, and the
addition of GOES satellite space enviFuture SPIDR development
ronment monitor data. These projects The SPIDR system is an actively are scheduled to be complete this year. evolving data access and visualization Additional databases and capabilities
will be added subseONE MINUTE VARIATION OF GECHAGNETIC FIELD
quently including 163.. POSTE DE LA BEU UT: 953 LON: 202. 01/29/1995 Surveyor DMSP global daily
X, Y, Z in ni
maps, solar cosmic ray
For information about
Eric Kihn, SPIDR Mgr.
A Figure 6. Geomagnetic one-minute variations for 1990 through 1996 reside in a database management system. Selected data are plotted and distributed over the WWW.
A Figure 7. DMSP visible image, Jan. 29, 1995, showing aurora over Canada and Greenland and city lights in Nova Scotia.
The state of the climate 1996 Summary of the Policymakers' Report of the Intergovernmental Panel on Climate Change
Edited by Robert Quayle
enough to more than offset the warming due to greenhouse gases. In contrast to the long-lived greenhouse gases, anthropogenic aerosols are very short-lived in the atmosphere. Hence, their effect changes rapidly with increases or decreases in emissions.
centrations for at least two centuries, approaching a doubling of pre-industrial levels (from 280 to 500 parts per million volume) by the end of the 21st century. Various computer models indicate that stabilization of atmospheric CO, concentrations at 450, 650, or 1000 ppmv could be achieved only if global emissions drop to 1990 levels approximately 40, 140, or 240 years from now, respectively, and then drop substantially below 1990 levels.
Stabilizing Co, concentration is governed more by the accumulated an
The period from 1990 to 1995 saw major advancements in the field of climatology. In particular, climatologists improved their ability to determine the probable causes of some observed features of the recent climate record. Increases in greenhouse gas concentrations since the mid-1700s have apparently warmed the surface of the Earth, and have likely produced other climate changes. The atmospheric concentrations of carbon dioxide (CO2), methane (CH2), and nitrous oxide (N2O) have continued to increase, largely as a result of human activities, use of fossil fuels, land use changes, and agricultural practices. Recent data indicate that the growth rates in the concentrations of these gases are comparable to the growth rates of the 1980s.
The heat trapping effects caused by increases of the long-lived greenhouse gases (the greenhouse effect) is due primarily to increases in the concentrations of carbon dioxide and methane. Since carbon dioxide remains in the atmosphere for many decades to centuries, its effect is measured in similarly long time scales.
Growth in the concentrations of CFCs and similar ozone-depleting gases has slowed, and the consequent ozone depletion is expected to decrease substantially by the year 2050, largely through the implementation of the Montreal Protocol. Some long-lived greenhouse gases, including a CFC substitute, contribute little to global warming now, but their projected growth could contribute several percent during the 21st century.
If carbon dioxide emissions were maintained at 1994 levels, they would lead to an increase in atmospheric con
Recent years have been
among the warmest since 1860...despite the
cooling effect of the June 1991 Mt. Pinatubo
thropogenic Co, emissions from now until the time of stabilization than by the way those emissions change over the period. Thus, for a given stabilized concentration value, higher emissions in early decades require lower emissions later on. Among the models run for stabilization at 450, 650, or 1000 ppmv, accumulated anthropogenic emissions over the period 1991 to the year 2100 are 630, 1030, and 1410 billion metric tons of carbon respectively. Stabilization of CH, and N, O concentrations at today's levels would involve reductions in anthropogenic emissions of 8% and more than 50%, respectively.
Anthropogenic aerosols (tiny particles such as those that produce smog) tend to produce a net cooling effect on the surface climate. Aerosols in the lower atmosphere resulting from combustion of fossil fuels, biomass burning, and other sources can have continental to hemispherical effects on climate. Locally, the aerosol forcing can be large
Climate change during the 20th century
At any one place, year-to-year variations in weather can be large, but analyses of meteorological and other data over large areas and over periods of decades or more have provided evidence for some important systematic changes. Global mean surface air temperature has increased by between about 0.3 and 0.6 degrees Celsius (about 0.5 and 1.0 degree Fahrenheit) since the late 19th century. This trend has been well publicized for some years and research during the intervening years has tended to reinforce the view that the warming is real, and not an artifice of the data.
Recent years have been among the warmest since 1860, i.e., in the period of instrumental record, despite the cooling effect of the June 1991 Mt. Pinatubo volcanic eruption. Nighttime temperatures over land have generally increased more than daytime temperatures. Regional changes are also evident. For example, the recent warming has been greatest over the mid-latitude continents in winter and spring.
There have also been a few areas of cooling, such as the North Atlantic ocean. Precipitation has increased over land in high latitudes of the Northern Hemisphere, especially during the cold season. Global sea level has risen by between 10 and 25 cm (about five and ten inches) over the past 100 years, and much of this rise may be related to the increase in global mean temperature.
There are inadequate data to determine whether consistent global changes in climate variability or weather extremes have occurred over the 20th century. The mid 1990 to mid-1995 persistent warm-phase of the El NinoSouthern Oscillation (ENSO), which causes droughts and floods in many areas, was unusual in light of the 120year record of this phenomenon.
National Climatic Data Center
Possible human influences on climate
Any human-induced effect on climate will be superimposed on a background of natural climate variability resulting from internal fluctuations and external causes such as solar variability or volcanic eruptions. Detection and attribution studies attempt to distinguish between anthropogenic and natural influences. “Detection of change" is the process of demonstrating that an observed change in climate is highly unusual in a statistical sense, but it does not provide a reason for the change.
"Attribution" is the process of establishing cause-and-effect. During the period from 1990 to 1995, considerable progress was made in distinguishing between natural and human influences on climate. This progress has been achieved by including effects of aerosols in addition to greenhouse gases in climate model simulations of the humaninduce climate change 'signal.'
In addition, new simulations with coupled atmosphere-ocean models have provided important information about decade to century time-scale natural climate variability. A further major area of progress is the shift of focus from studies of global-mean changes to comparisons of modelled and observed spatial and temporal patterns of climate change.
The most important results related to the issues of detection and attribution are: • The limited available evidence from proxy climate indicators suggests that the 20th century global mean temperature is at least as warm as any other century since at least 1400 AD. Data prior to 1400 are too sparse to allow the reliable estimation of global mean temperature. • Assessments of the statistical significance of the observed global mean surface air temperature trend over the last century have used a variety of new estimates of natural internal and externallyforced variability. These were derived from instrumental data, paleodata, simple and complex climate models, and statistical models fitted to observations. Most of these studies have detected a significant change and show that the observed warming trend is unlikely to be entirely natural in origin. • Convincing new evidence for the attribution of a human effect on climate
is emerging from studies in which the modelled climate is compared with observed patterns of atmospheric temperature change. These studies show that the pattern correspondence increases with time, as one would expect for an increasing anthropogenic signal. Furthermore, the probability is very low that these correlations could occur by chance as a result of natural internal variability alone.
Our ability to quantify the human influence on global climate is currently limited because the expected sig. nal is still emerging from the noise of natural variability, and because there are uncertainties in key factors. These include the magnitude and patterns of long-term natural variability and the time-evolving pattern of forcing by, and response to, changes in the concentrations of greenhouse gases and aerosols, and land surface changes. Nevertheless, the balance of evidence suggests that there is discernible human influence on global climate.
degrees F) by 2100, and the highest gives a warming of about 3.5 degrees Celsius (7 degrees F). In all cases the average rate of warming would probably be greater than any seen in the
last 10,000 years, but the actual annual to decadal changes would include considerable natural variability.
Regional temperature changes could differ substantially from the global mean value. Because of the thermal inertia of the oceans, only 50-90% of the eventual equilibrium would
continue to increase be
yond 2100, even if the concentrations of greenhouse gases were stabilized by that time.
Average sea level is expected to rise as a result of thermal expansion of the oceans and melting of glaciers and icesheets. The “best estimate" models project an increase in sea level of about 50 cm (20 inches) from the present to 2100. The lowest projected sea level rise is about 15 cm (6 inches), and the highest is projected at about 95 cm (37 inches) from the present to 2100. Sea level would continue to rise at a similar rate beyond 2100, even if concentrations of greenhouse gases were stabilized by that time, and would continue to do so past the time of stabilization of global mean temperature. Regional sea level changes may differ from the global mean value owing to land movement and ocean current changes.
Confidence is higher in the hemispheric-to-continental scale projections of coupled atmosphere-ocean climate models than in the regional projections, where confidence remains low. There is more confidence in temperature projections than hydrological changes.
All model simulations, whether they were forced with increased concentrations of greenhouse gases and aerosols or with increases concentrations of greenhouse gases alone, show: greater surface warming of the land than of the sea in winter; a maximum surface warming in high northern latitudes in winter; little surface warming over the
- continued on page 16
Expected changes in global climate
The Intergovernmental Panel on Climate Change (IPCC) has developed a range of possible future greenhouse gas and aerosol concentrations based on several different assumptions for the period 1990 to 2100. These emissions can then be used to predict the climate. The increasing realism of simulations of current and past climate by coupled atmosphere-ocean climate models has increased our confidence in their use for projection of future climate change. Important uncertainties remain, but these have been taken into account in the full range of projections of global mean temperature and sea level change.
For the mid-range IPCC emission scenario, assuming the "best estimate" values of the variables, models project an increase in global mean surface air temperature relative to 1990 of about 2 degrees Celsius (4 degrees Fahrenheit) by 2100. The lowest IPCC projected increase is about 1 degree Celsius (2