Biogenic nuclei involvement in clouds over the Ross Ice Shelf
from 6.6 x 1015 to 3.4 x 10 16 per second. Using the measured plume characteristics for 14 November 1980, the sulfate aerosol flux, derived from the filter samples, was estimated at 0.06 kilograms per second (or 2,000 tons per year). My estimates of the sulfur emission fluxes from Mount Erebus are substantially greater than estimates by Faivre-Pierret (1978) and by Polian and Lambert (1979). Polian and Lambert estimated that .001 ton of sulfate [SO2 + particulate sulfate (SO] is emitted by Mount Erebus each year. Since the estimated total sulfate budget for Antarctica is 130,000 to 200,000 tons per year (Boutron personal communication; Shaw 1980), Polian and Lambert concluded that the emissions from Mount Erebus were unimportant in the sulfate budget of Antarctica. Obviously this conclusion must be reexamined in the light of my measurement of 42,000 tons per year of total sulfate emissions from Mount Erebus. If my measurements are representative, then as much as 32 percent of the antarctic total sulfate budget could be provided by Mount Erebus. This study was supported by National Science Foundation grant DPP 79-20857. Thanks are due J . Russell, field engineer, and the VXE-6 flight crews. I also thank Peter V. Hobbs for his scientific advice and J . Lyons for help with data reduction. This is contribution 649 of the University of Washington Atmospheric Sciences Department.
References Boutron, C. Personal communication, 1982. Boutron, C., and Delmas, R. 1980. Historical record of global atmospheric pollution revealed in polar ice sheets. Ambio, 9, 210-215. Faivre-Pierret, R. Unpublished report, 1978. (See Polian, C., and Lambert, C., 1979, Radon daughters and sulfur output from Erebus Vol-
Biogenic nuclei involvement in clouds over the Ross Ice Shelf V. K. SAXENA
Cloud-Aerosol Interactions Laboratory Department of Marine, Earth, and Atmospheric Sciences North Carolina State University Raleigh, North Carolina 27650
The antarctic coastal clouds that form as a result of advection of marine air over the Ross Ice Shelf were investigated during October-November 1980. Measurements of the spatial and temporal distribution of Aitken and cloud condensation nuclei concentration in the subcloud layer have been reported elsewhere (Saxena 1981; Saxena and Baier 1981). This article presents the results of analysis of the chemical composition of the cloud water. Samples of the cloud water were collected at around 75°53'S 172°20'E during a ifight of the LC-130 in November 1980. A 212
cano, Antarctica, Journal of Volcanology and Geothermal Research, 6, 125-137.)
Herron, M. M. 1982. Impurity sources of F-, Cl, NO 3 and SO,'- in Greenland and antarctic precipitation. Journal of Geophysical Research, 87, 3052-3060.
Hobbs, P. V., Tuell, J. P., Radke, L. F., Hegg, D. A., and Eltgroth, M. W. In press. Particles and gases in the emissions from the 1980-81 volcanic eruptions of Mt. St. Helens. Journal of Geophysical Research. Kyle, P. R., Giggenbach, W. F., and Keys, H. J . R. 1976. Volcanic activity of Mount Erebus, Ross Island. Antarctic Journal of the U. S., 2, 270-271.
Maenhaut, W., Zoller, W. H., Duce, R. E., and Hoffman, G. L. 1979. Concentration and size distribution of particulate trace elements in the south polar atmosphere. Journal of Geophysical Research, 84, 2421-2431. Polian, G., and Lambert, G. 1979. Radon daughters and sulfur output from Erebus volcano, Antarctica. Journal of Volcanology and Geothermal Research, 6, 125-137. Quartermain, L. B. 1967. South to the Pole-The early history of the Ross Sea Sector, Antarctica. London: Oxford University Press. Radke, L. F. 1981. Airborne measurements of particle size distributions in noneruptive volcanic emissions. Antarctic Journal of the U.S., 16(5), 196-197. Radke, L. F. In press. Sulfur and sulfate from Mt. Erebus. Nature. Radke, L. F., Hobbs, P. V., and Stith, J. L. 1976. Airborne measurements of gases and aerosols from volcanic vents on Mt. Baker. Geophysical Research Letters, 3, 93-96. Shaw, G. E. 1979. Considerations on the origin and properties of the antarctic aerosol. Review of Geophysics and Space Physics, 17, 1983-1998. Shaw, G. E. 1980. Optical, chemical and physical properties of aerosols over the antarctic ice sheet. Atmospheric Environment, 14, 911-921. Stith, J. L., Hobbs, P. V., and Radke, L. F. 1978. Airborne particle and gas measurements in the emissions from six volcanoes. Journal of Geophysical Research. 83, 4009-4017. Zettwoog, P., and Haulet, R. 1978. Experimental results on the S02 transfer in the Mediterranean with remote sensing devices. Atmospheric Environment, 12, 795-796.
semicylindrical Teflon probe, 45.7 centimeters long and having an outside diameter of 3.2 centimeters, was projected through the sextant hole in the cockpit. The probe projected well beyond the surface boundary layer at the aircraft's cruising speed. The supercooled water droplets froze upon impact on the Teflon probe, enabling collection of cloud water in a solid phase (in a clear plastic bag). Prior to sampling, the probe was thoroughly rinsed with distilled, deionized water and dried. The cloud water samples were analyzed with a Perkin-Elmer infrared spectrophotometer, an electron microscope, and an Xray energy dispersion spectrometer. An algae grew on cloud water allowed to stand at 20°C under diffused sunlight for 4 weeks. An electron micrograph of this algae is shown in figure 1 (top). Also shown (figure 1, bottom) is the X-ray energy-dispersive analysis of the specimen. For the analysis, the water was allowed to dry on the face of a scrupulously cleaned germanium internal-reflection prism. The right-hand peak is characteristic of germanium. Elemental composition consisted of aluminum, silicon, sulfur, chlorine, and potassium. The abundance of silicon and potassium was about the same; sulfur apparently was the most abundant. Mount Erebus, an active volcano, is the only natural source of sulfur on the Antarctic Continent. Previous findings (Cadle et al. 1968) have led to the hypothesis that ANTARCTIC JOURNAL
the sulfate particles originate in the Junge sulfate layer, and that stratospheric-tropospheric exchange brings them into the lower troposphere where they may get involved in the process of cloud formation. Figure 2 (top) shows the rings formed by the residue submicron particles contained in the cloud water. Within each ring there are several submicron particles. Elemental composition of these particles may differ slightly, but an average representation can be worked out. Figure 2 (bottom) shows this average composition; the various peaks in the figure indicate the presence of sodium, silicon, phosphorous, sulfur, chlorine, potassium, and calcium. Some tentative conclusions can be drawn from these analyses. The algae seen in figure 1 as fibrous and sheet-like matter can be identified as planktonema lauterbornii. The growth of an
__
4
Figure 2. Top: Electron micrograph of the desiccated cloud water sample on the face of a germanium internal-reflection prism. Submicron particles are clustered around rings. Bottom: Typical X-ray energy-dispersive spectrum of a submicron particle shown at left. Contrast this with figure 1 (bottom). Peaks show the presence of, and Indicate the relative abundance of, sodium (Na), silicon (Si), phosphorous (P), sulfur (S), chlorine (Cl), potassium (K), and calcium (Ca).
Figure 1. Top: Electron micrograph of algae that grew In antarctic cloud water collected through direct aircraft penetration, November 1980, around 75 053'S 172020'E. Bottom: X-ray energy-dispersive spectrum of the sample shown at left. Peaks indicate the presence of aluminum (Al), silicon (Si), sulfur (S), chlorine (Cl), and potassium (K). The end peak is characteristic of germanium.
1982 REVIEW
algae in "clean" antarctic cloud water, sampled through direct aircraft penetration with utmost care to avoid contamination, warrants further investigation because it indicates the presence of biogenic material in antarctic clouds. As reported earlier (Saxena 1981), infrared absorption spectra of the cloud water specimen have consistently indicated the presence of the proteinaceous matter. Evidence presented in figure 2 indicates that potassium and chlorine are relatively more abundant than sodium, and that the major ionically bonded salt in the cloud water is potassium chloride rather than sodium chloride. It is well understood that 213
potassium chloride is enriched inside biological cells. These three pieces of evidence seem to confirm that cloud condensation nuclei of biogenic origin, such as those derived from plankton in the southern ocean, actively participate in the process of cloud formation over the Ross Ice Shelf. Frequently, these clouds produce snow. The biogenic nuclei may be initiating the condensation-freezing mechanism that helps these clouds precipitate. Previous studies (Schnell and Vali 1976; Vali et al. 1976) have indicated that biogenic nuclei exhibit good icenucleating activity. Precipitation in the Southern Hemisphere (e.g., New Zealand) is known to be more nutrient-laden than that in the Northern Hemisphere. Maclntyre (1974) has discussed the recipe for rainwater for a small town on the New Zealand coast. The biological material in the precipitation samples represented one thousand times the amount of organics normally present in seawater. The processes by which this material finds its way into the atmosphere are still not understood, and heretofore there has been no report of plankton and algae in cloud water, though these things are an integral part of rainwater in New Zealand. Our measurements have indicated that the biogenic material, which may be derived from plankton, is present in the cloud water. This finding provides an insight into the relationship between macroscopic meteorology and microlayer oceanography. In the antarctic region, biogenic nuclei may be treated as a tracer for air masses that advect from the plankton-rich ocean
onto the continent. Analysis of the transport processes of these nuclei clearly will require additional extensive measurements. This work was supported by National Science Foundation grant DPP 79-22058. The assistance of Robert E. Baier, Arvin Caispan Advanced Technology Center, in analyzing the cloud water samples is gratefully acknowledged.
References Cadle, R. D., Fischer, W. H., Frank, E. R., and Lodge, J. P., Jr. 1968. Particles in the antarctic atmosphere. Journal of the Atmospheric Sciences, 25, 100-103. Macintyre, F. 1974. The top millimeter of the ocean. Scientific American, 230(5), 62-67. Saxena, V. K. 1981. Microphysical measurements in antarctic coastal clouds and the subcloud layer. Antarctic Journal of the U.S., 16(5), 187-188. Saxena, V. K., and Baier, R. E. 1981. Evidence of biogenic nuclei involvement in the antarctic coastal clouds. Programs and Abstracts of the International Conference on Condensation and Ice Nuclei, Hamburg, Germany, 26-28 August 1981. Schnell, R. C., and Vali, C. 1976. Biogenic ice nuclei. Part I: Terrestrial and marine sources. Journal of the Atmospheric Sciences, 33, 15544564. Vali, G., Christensen, M., Fresh, R. W., Galyan, E. L., Maki, L. R., and Schnell, R. C. 1976. Biogenic ice nuclei. Part II: Bacterial sources. Journal of the Atmospheric Sciences, 33, 1565-1570.
Analysis of antarctic automatic weather station data from the western Ross Sea/Ice Shelf ROBERT J . RENARD and WILLIAM J. THOMPSON
Naval Postgraduate School Monterey, California 93940
In the Antarctic, where fewer than 30 manned stations lie scattered over vast regions and where surface visibility can decrease rapidly, endangering field parties and air operations, the automatic weather station is one way of collecting muchneeded meteorological data. Designed to operate under severe weather conditions automatic weather stations (Aws) currently provide reliable and accurate observations of surface pressure, wind, and temperature, for potential use in research on antarctic circulations. The data are available on a real-time basis (via satellite) to the Naval Support Force Antarctica weather center at McMurdo Station (figure 1). A prototype station was installed at each of three antarctic locations in 1975-77. A second-generation station was deployed at each of seven locations during the 1978-79 austral summer. Five of these stations were located around McMurdo to provide warning of worsening weather conditions and to collect data for analyzing subsynoptic-scale circulations affecting the McMurdo operating area. In the summer of 1980-81, three stations were redeployed further east and southeast over the Ross Ice Shelf. During the 1981-82 season three new stations were added, 214
Figure 1. Automatic weather station "Jimmy" (2.5 nautical miles north-northeast of McMurdo). From left to right: C. S. Stearns and M. L. Savage, University of Wisconsin, and W. J. Thompson, Naval Postgraduate School.
bringing the total in the McMurdo area to eight stations (figure 2). The data from the three prototype stations were analyzed at the Naval Postgraduate School to establish the credibility of the observations and their uniqueness to antarctic operations (Renard and Salinas 1977). Analysis of data from the second-generation stations (covering the period January 1979-February 1980) was completed recently (Scarbro 1982). Considerable statistical ANTARCTIC JOURNAL
References Boutron, C. Personal communication, 1982. Boutron, C., and Delmas, R. 1980. Historical record of global atmospheric pollution revealed in polar ice sheets. Ambio, 9, 210-215. Faivre-Pierret, R. Unpublished report, 1978. (See Polian, C., and Lambert, C., 1979, Radon daughters and sulfur output from Erebus Vol-
Biogenic nuclei involvement in clouds over the Ross Ice Shelf V. K. SAXENA
Cloud-Aerosol Interactions Laboratory Department of Marine, Earth, and Atmospheric Sciences North Carolina State University Raleigh, North Carolina 27650
The antarctic coastal clouds that form as a result of advection of marine air over the Ross Ice Shelf were investigated during October-November 1980. Measurements of the spatial and temporal distribution of Aitken and cloud condensation nuclei concentration in the subcloud layer have been reported elsewhere (Saxena 1981; Saxena and Baier 1981). This article presents the results of analysis of the chemical composition of the cloud water. Samples of the cloud water were collected at around 75°53'S 172°20'E during a ifight of the LC-130 in November 1980. A 212
cano, Antarctica, Journal of Volcanology and Geothermal Research, 6, 125-137.)
Herron, M. M. 1982. Impurity sources of F-, Cl, NO 3 and SO,'- in Greenland and antarctic precipitation. Journal of Geophysical Research, 87, 3052-3060.
Hobbs, P. V., Tuell, J. P., Radke, L. F., Hegg, D. A., and Eltgroth, M. W. In press. Particles and gases in the emissions from the 1980-81 volcanic eruptions of Mt. St. Helens. Journal of Geophysical Research. Kyle, P. R., Giggenbach, W. F., and Keys, H. J . R. 1976. Volcanic activity of Mount Erebus, Ross Island. Antarctic Journal of the U. S., 2, 270-271.
Maenhaut, W., Zoller, W. H., Duce, R. E., and Hoffman, G. L. 1979. Concentration and size distribution of particulate trace elements in the south polar atmosphere. Journal of Geophysical Research, 84, 2421-2431. Polian, G., and Lambert, G. 1979. Radon daughters and sulfur output from Erebus volcano, Antarctica. Journal of Volcanology and Geothermal Research, 6, 125-137. Quartermain, L. B. 1967. South to the Pole-The early history of the Ross Sea Sector, Antarctica. London: Oxford University Press. Radke, L. F. 1981. Airborne measurements of particle size distributions in noneruptive volcanic emissions. Antarctic Journal of the U.S., 16(5), 196-197. Radke, L. F. In press. Sulfur and sulfate from Mt. Erebus. Nature. Radke, L. F., Hobbs, P. V., and Stith, J. L. 1976. Airborne measurements of gases and aerosols from volcanic vents on Mt. Baker. Geophysical Research Letters, 3, 93-96. Shaw, G. E. 1979. Considerations on the origin and properties of the antarctic aerosol. Review of Geophysics and Space Physics, 17, 1983-1998. Shaw, G. E. 1980. Optical, chemical and physical properties of aerosols over the antarctic ice sheet. Atmospheric Environment, 14, 911-921. Stith, J. L., Hobbs, P. V., and Radke, L. F. 1978. Airborne particle and gas measurements in the emissions from six volcanoes. Journal of Geophysical Research. 83, 4009-4017. Zettwoog, P., and Haulet, R. 1978. Experimental results on the S02 transfer in the Mediterranean with remote sensing devices. Atmospheric Environment, 12, 795-796.
semicylindrical Teflon probe, 45.7 centimeters long and having an outside diameter of 3.2 centimeters, was projected through the sextant hole in the cockpit. The probe projected well beyond the surface boundary layer at the aircraft's cruising speed. The supercooled water droplets froze upon impact on the Teflon probe, enabling collection of cloud water in a solid phase (in a clear plastic bag). Prior to sampling, the probe was thoroughly rinsed with distilled, deionized water and dried. The cloud water samples were analyzed with a Perkin-Elmer infrared spectrophotometer, an electron microscope, and an Xray energy dispersion spectrometer. An algae grew on cloud water allowed to stand at 20°C under diffused sunlight for 4 weeks. An electron micrograph of this algae is shown in figure 1 (top). Also shown (figure 1, bottom) is the X-ray energy-dispersive analysis of the specimen. For the analysis, the water was allowed to dry on the face of a scrupulously cleaned germanium internal-reflection prism. The right-hand peak is characteristic of germanium. Elemental composition consisted of aluminum, silicon, sulfur, chlorine, and potassium. The abundance of silicon and potassium was about the same; sulfur apparently was the most abundant. Mount Erebus, an active volcano, is the only natural source of sulfur on the Antarctic Continent. Previous findings (Cadle et al. 1968) have led to the hypothesis that ANTARCTIC JOURNAL
the sulfate particles originate in the Junge sulfate layer, and that stratospheric-tropospheric exchange brings them into the lower troposphere where they may get involved in the process of cloud formation. Figure 2 (top) shows the rings formed by the residue submicron particles contained in the cloud water. Within each ring there are several submicron particles. Elemental composition of these particles may differ slightly, but an average representation can be worked out. Figure 2 (bottom) shows this average composition; the various peaks in the figure indicate the presence of sodium, silicon, phosphorous, sulfur, chlorine, potassium, and calcium. Some tentative conclusions can be drawn from these analyses. The algae seen in figure 1 as fibrous and sheet-like matter can be identified as planktonema lauterbornii. The growth of an
__
4
Figure 2. Top: Electron micrograph of the desiccated cloud water sample on the face of a germanium internal-reflection prism. Submicron particles are clustered around rings. Bottom: Typical X-ray energy-dispersive spectrum of a submicron particle shown at left. Contrast this with figure 1 (bottom). Peaks show the presence of, and Indicate the relative abundance of, sodium (Na), silicon (Si), phosphorous (P), sulfur (S), chlorine (Cl), potassium (K), and calcium (Ca).
Figure 1. Top: Electron micrograph of algae that grew In antarctic cloud water collected through direct aircraft penetration, November 1980, around 75 053'S 172020'E. Bottom: X-ray energy-dispersive spectrum of the sample shown at left. Peaks indicate the presence of aluminum (Al), silicon (Si), sulfur (S), chlorine (Cl), and potassium (K). The end peak is characteristic of germanium.
1982 REVIEW
algae in "clean" antarctic cloud water, sampled through direct aircraft penetration with utmost care to avoid contamination, warrants further investigation because it indicates the presence of biogenic material in antarctic clouds. As reported earlier (Saxena 1981), infrared absorption spectra of the cloud water specimen have consistently indicated the presence of the proteinaceous matter. Evidence presented in figure 2 indicates that potassium and chlorine are relatively more abundant than sodium, and that the major ionically bonded salt in the cloud water is potassium chloride rather than sodium chloride. It is well understood that 213
potassium chloride is enriched inside biological cells. These three pieces of evidence seem to confirm that cloud condensation nuclei of biogenic origin, such as those derived from plankton in the southern ocean, actively participate in the process of cloud formation over the Ross Ice Shelf. Frequently, these clouds produce snow. The biogenic nuclei may be initiating the condensation-freezing mechanism that helps these clouds precipitate. Previous studies (Schnell and Vali 1976; Vali et al. 1976) have indicated that biogenic nuclei exhibit good icenucleating activity. Precipitation in the Southern Hemisphere (e.g., New Zealand) is known to be more nutrient-laden than that in the Northern Hemisphere. Maclntyre (1974) has discussed the recipe for rainwater for a small town on the New Zealand coast. The biological material in the precipitation samples represented one thousand times the amount of organics normally present in seawater. The processes by which this material finds its way into the atmosphere are still not understood, and heretofore there has been no report of plankton and algae in cloud water, though these things are an integral part of rainwater in New Zealand. Our measurements have indicated that the biogenic material, which may be derived from plankton, is present in the cloud water. This finding provides an insight into the relationship between macroscopic meteorology and microlayer oceanography. In the antarctic region, biogenic nuclei may be treated as a tracer for air masses that advect from the plankton-rich ocean
onto the continent. Analysis of the transport processes of these nuclei clearly will require additional extensive measurements. This work was supported by National Science Foundation grant DPP 79-22058. The assistance of Robert E. Baier, Arvin Caispan Advanced Technology Center, in analyzing the cloud water samples is gratefully acknowledged.
References Cadle, R. D., Fischer, W. H., Frank, E. R., and Lodge, J. P., Jr. 1968. Particles in the antarctic atmosphere. Journal of the Atmospheric Sciences, 25, 100-103. Macintyre, F. 1974. The top millimeter of the ocean. Scientific American, 230(5), 62-67. Saxena, V. K. 1981. Microphysical measurements in antarctic coastal clouds and the subcloud layer. Antarctic Journal of the U.S., 16(5), 187-188. Saxena, V. K., and Baier, R. E. 1981. Evidence of biogenic nuclei involvement in the antarctic coastal clouds. Programs and Abstracts of the International Conference on Condensation and Ice Nuclei, Hamburg, Germany, 26-28 August 1981. Schnell, R. C., and Vali, C. 1976. Biogenic ice nuclei. Part I: Terrestrial and marine sources. Journal of the Atmospheric Sciences, 33, 15544564. Vali, G., Christensen, M., Fresh, R. W., Galyan, E. L., Maki, L. R., and Schnell, R. C. 1976. Biogenic ice nuclei. Part II: Bacterial sources. Journal of the Atmospheric Sciences, 33, 1565-1570.
Analysis of antarctic automatic weather station data from the western Ross Sea/Ice Shelf ROBERT J . RENARD and WILLIAM J. THOMPSON
Naval Postgraduate School Monterey, California 93940
In the Antarctic, where fewer than 30 manned stations lie scattered over vast regions and where surface visibility can decrease rapidly, endangering field parties and air operations, the automatic weather station is one way of collecting muchneeded meteorological data. Designed to operate under severe weather conditions automatic weather stations (Aws) currently provide reliable and accurate observations of surface pressure, wind, and temperature, for potential use in research on antarctic circulations. The data are available on a real-time basis (via satellite) to the Naval Support Force Antarctica weather center at McMurdo Station (figure 1). A prototype station was installed at each of three antarctic locations in 1975-77. A second-generation station was deployed at each of seven locations during the 1978-79 austral summer. Five of these stations were located around McMurdo to provide warning of worsening weather conditions and to collect data for analyzing subsynoptic-scale circulations affecting the McMurdo operating area. In the summer of 1980-81, three stations were redeployed further east and southeast over the Ross Ice Shelf. During the 1981-82 season three new stations were added, 214
Figure 1. Automatic weather station "Jimmy" (2.5 nautical miles north-northeast of McMurdo). From left to right: C. S. Stearns and M. L. Savage, University of Wisconsin, and W. J. Thompson, Naval Postgraduate School.
bringing the total in the McMurdo area to eight stations (figure 2). The data from the three prototype stations were analyzed at the Naval Postgraduate School to establish the credibility of the observations and their uniqueness to antarctic operations (Renard and Salinas 1977). Analysis of data from the second-generation stations (covering the period January 1979-February 1980) was completed recently (Scarbro 1982). Considerable statistical ANTARCTIC JOURNAL
