interest are the properties of neutron stars, which are exotic 

 end-products of some supernova explosions and the sites of 

 high-energy radiation. Other simulations include problems in 

 star formation and the evolution of stellar-planetary systems, 

 including collisions among major planetary bodies in the 

 early solar system. 



Science Education and Outreach 



SAO has developed a varied approach to science education and 

 outreach designed to reach three ma|or audiences: the general 

 public, precollege science teachers and students, and the aca- 

 demic community, including both undergraduate and gradu- 

 ate students. 



A grant from the National Science Foundation allowed 

 SAO to provide io-week summer internships for 13 college 

 undergraduates specializing in astronomy and astrophysics. 

 The program, which emphasizes opportunities for women and 

 minorities, will be conducted at the Observatory for two more 

 summers. 



SAO's Science Media Group received a grant from the 

 Annenberg/CPB Math and Science project to develop six edu- 

 cational videos exploring common student misconceptions in 

 science. As part of "The Private Universe Project," a series of 

 nationally televised interactive evaluation conferences will 

 elicit comment and consultation on the videos from teachers. 



Considerable progress was made in the development of ex- 

 hibitry and displays for the Whipple Observatory's Visitor 

 Center in Arizona. Completion, and official "opening," is ex- 

 pected in January 1995, in time for the winter meeting of the 

 American Astronomical Society in Tucson. In collaboration 

 with the USDA/Forest Service, a "trailhead," with picnic area, 

 rest rooms, and nature trail, was created near the Visitors Cen- 

 ter to serve recreational users of the Coronado National Forest 

 where the Observatory is located. 



Smithsonian Environmental Research Center 



David L. Correll, Director 



The Smithsonian Environmental Research Center (SERC) 

 maintained its research and education programs with a focus 

 on the interactions of flora and fauna with their environment. 

 Construction of the second phase of a four-phased addition to 

 the Charles Mathias Laboratory Building was initiated. The 

 design packages were completed for an office building to re- 

 place the Old Dominion building, which will then be demol- 

 ished, and for a new education building near the Rhode River 

 shoreline. 



This year SERC scientists published 35 research papers as a 

 result of a series of ongoing atmospheric, terrestrial, and 

 aquatic studies. SERC has been monitoring surface ultraviolet 

 (UV) spectral radiation in the 290-325 nm wavelength range 



at Mauna Loa, Hawaii since the fall of 1984 with the objective 

 of detecting long-term trends resulting from changes in the 

 stratospheric ozone layer or atmospheric aerosols. The instru- 

 ment used was designed, built, and calibrated at SERC. In 

 1991 the volcano, Mount Pinatubo in the Philippines had a 

 major eruption and injected large amounts of sulphate into 

 the stratosphere. This resulted not only in greatly increased at- 

 mospheric turbidity due to aerosols, but also for several years 

 in unanticipated widespread declines in stratospheric ozone. 

 When SERC UV radiation data were compared with changes 

 in ozone and aerosols prior to and subsequent to the volcanic 

 eruption, it was clear that changes in ozone had a greater influ- 

 ence on UV radiation than aerosols. Changes in aerosols ex- 

 plained very little of the change in 300 nm radiation, but at 

 increasing wavelengths their effects increased so that they ex- 

 plained 17% of the change in 325 nm radiation. 



In recent decades in the antarctic the natural seasonal oscil- 

 lation in the thickness of the stratospheric ozone layer has 

 been amplified due to the effects of atmospheric pollution, the 

 so-called "ozone hole". SERC scientists have been studying 

 whether the resulting increases in solar ultraviolet radiation 

 (UV) in the range from 280 to 400 nm have a significant im- 

 pact on marine phytoplankton. Studies of photosynthesis of 

 natural antarctic phytoplankton assemblages and algal cul- 

 tures found that the algae reach a steady-state in which the 

 rate of UV inhibition of photosynthesis is balanced by the rate 

 of recovery. Although a photon in the range of 280 to 320 nm 

 caused more inhibition, the flux of photons in the range of 

 320 to 400 nm is so much larger that more inhibition was 

 caused by this part of the UV spectrum. 



Ecological studies of terrestrial orchid seeds have long been im- 

 peded by the fact that the seeds are very small and their germina- 

 tion often depends upon symbiotic or parasitic relationships with 

 organisms. The young seedlings also live as parasites on fungi 

 and remain underground for periods of up to years after germina- 

 tion. SERC scientists devised a method which allows these orchid 

 seeds to be sown and retrieved in the field under almost natural 

 conditions. Five species of orchid were srudied and all began to 

 germinate in May or June after 23 to 30 weeks in the soil. None 

 of the seedlings of these species developed beyond very early ger- 

 mination stages unless they were infected with fungi. This tech- 

 nique makes it feasible to carry out many detailed ecological 

 studies of these interesting plants. 



Methane is an important "greenhouse" gas which is increas- 

 ing in the Earth's atmosphere. It is believed that 40% of the 

 methane entering the atmosphere originates from wetlands 

 and rice paddies. SERC scientists investigated the effects of in- 

 creased concentrations of atmospheric carbon dioxide, another 

 greenhouse gas, on methane emission from tidal marsh plant 

 communities. When the sedge Scirpus olneyi was exposed to 

 the level of carbon dioxide expected in the atmosphere 

 50 years from now, methane emissions were nearly double 

 those from control plots of the sedge. Thus, as carbon dioxide 

 increases methane emissions from these marshes may also in- 

 crease, further increasing the potential for global warming. 



SO 



