Antarctic automatic weather stations
Climate studies Antarctic automatic weather stations: Austral summer 1993-1994 and ROBERT E. HOLMES, Space Science and Engineering Center, University of Wisconsin, Madison, Wisconsin 53706
CHARLES R. STEARNS, GEORGE A. WEIDNER,
he National Science Foundation's Office of Polar Proeral experiments, and all contribute to operational purposes T grams places automatic weather station (AWS) units in especially for preparing weather forecasts for aircraft flights to remote areas in Antarctica in support of meteorological and from New Zealand and within Antarctica. research, applications, and operations. Some of the areas supported are the following: The basic AWS units measure air temperature, wind • Barrier wind flow studies along the Antarctic Peninsula speed, and wind direction at a nominal height of 3 meters (m) and in the Transantarctic Mountains; above the surface, and air pressure at the electronics enclo• Katabatic wind flow studies down the slope to the Adélie sure. Some units measure relative humidity at 3 m and the air Coast, Reeves Glacier, Byrd Glacier, and the Beardmore temperature difference between 3 m and 0.5 m above the surGlacier; face at the time of installation. The data are collected by the ARGOS Data Collection System on board the National Oceanic and Atmospheric Administration's series of polar-orbiting satellites. The table gives the AWS " 1994 AWS Sites 70* 60 units' site name, ARGOS identiof 1 March 1994 / as fication number, latitude, longitude, elevation above sea level, Island site start date, and WMO num• -Recovery Glacier 80 ber for the Global Telecommunications System for AWS units in operation as of 1 March 1994. Henry Figure 1 shows the locations of S clean frJr • .Nlco widely spaced AWS units in Antarctica; figure 2 shows the locations on Ross Island. The Byrd Station AWS units are grouped together 80 LettauS • based on the area and are usualDoZ Schwerdtfeger lyfl\ ly related to a single meteorona Bluff sow - - - - - - . Ferrell$ Pegasus North logical experiment in the area. 1 lartle Point Pegasus South;0 Willie Fieldf 4anuela\ Stearns and Weidner (1992) and 120 Sandra Whitlock Holmes, Weidner, and Stearns Ln (1993) describe the AWS activiDenlson Possession lstand• orarn ties during the two previous enguln Point austral summers. I •øVoung Island Scott Island The AWS units are located W 180 150E in arrays for meteorological experiments and at other sites Figure 1. Map of Antarctica showing the locations of widely spaced AWS units for 1994. The Cape Adams for operational purposes. Any AWS site is not shown because the unit could not be found. The Siple Station unit was removed and one AWS may contribute to sev- installed at Ski-Hi. Siple AWS site is decommissioned because of maintenance difficulty.
it4s
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The 1994 antarctic automatic weather station site name, ARGOS identification number, latitude, longitude, altitude above sea level, site start date, and WMO numberfor the Global Telecommunications System
Marble Point Ferrell Pegasus North Pegasus South Minna Bluff Linda Willie Field
Adélie Coast 8914 66.700S 139.800E 240 8916 67.380S 138.720E 1,560 8919 70.020S 134.72°E 2,500 8904 74.500S 123.00°E 3,280 8930 66.820S 141.390E 39 8933 67.020S 142.68°F 31 8929 67.620S 146.00°F 30 West Antarctica 8903 80.00°S 120.00°W 1,530 8981 73.200S 127.05°W 30 Ross Island region 8906 77.430S 163.750E 120 8934 78.020S 170.80°F 45 8927 77.950S 166.51°E 10 8937 78.030S 166.60°F 10 8988b,c 78.560S 166.69°F 920 8915 b 78.500S 168.35°F 50 8901 77.850S 167.08°F 40
Feb 80 89866 Dec 80 89872 Jan 90 89667 Jan 91 Jan 91 89768 Jan 91 89769 Jan 92
Whitlock Scott Island Young Island Possession Island
Ocean islands 8921b 76.240S 168.70°F 275 8983 67.370S 179.97°W 30 8980 66.280S 162.33°F 30 8984 71.900S 171.13°F 30
Jan 82 89865 Dec 87 89371 Dec 90 89660 Dec 92 89879
D-1 0 D-47 D-80 Dome C Port Martin Cape Denison Penguin Point Byrd Station Mount Siple
Ross Ice Shelf 8931 79.980S 165.03°F 75 8913 79.940S 169.83°F 60 8911 80.030S 1 78.63°W 55 8900 83.150S 174.46°F 60 8908C 82.52 0S 174.43°W 55 Reeves Glacier Manuela 8905 74.920S 163.60°F 80 Sandra 8923 74.480S 160.48°F 1,525 Lynn 8935 74.210S 160.39°F 1,772 Antarctic Peninsula Larsen Ice 8926 66.970S 60.55°W 17 Butler Island 8902 72.200S 60.34°W 91 Uranus 8920 71.430S 68.93°W 780 Cape Adams, inactive 75.01 0S 62.53°W 25 Racer Rocks 8947 64.160S 61 .54°W 17 Bonaparte Point 8912 64.780S 63.06°W 8 Recovery Glaciera 8932 80.820S 22.26°F 1,220 SkiHia 8917 74.970S 70.77°W 1,395 Marilyn Schwerdtfeger Gill Elaine Lettau
Feb 80 89832 Jan 83 89834 Nov 84 89836 Feb 80 89828 Jan 90 Jan 90 Dec 93 89847 Feb 80 89324 Feb 92 89327
Jan 84 89869 Jan 85 89868 Jan 85 89863 Jan 86 89873 Jan 86 89377 Feb 84 89864 Jan 88 89861 Jan 88 89860 Oct 85 89262 Mar 86 89266 Mar 86 89264 Jan 89 89268 Nov 89 89261 Nov 91 89269 Jan 94 Feb 94
High polar plateau Clean Air 8987b 90.00°S 2,835 Jan 86 89208 Henry 8985 89.00°S 0.30°W 2,755 Jan 93 89108 Nico 8924 89.00°S 90.13°F 2,935 Jan 93 89799 a New locations for 1994 bNew ARGOS ID at the site for 1994 C New latitude and/or longitude based on aircraft global positioning system
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malfunctioning aerovane at Schwerdtfeger site was replaced. A Twin Otter flight was made to Lettau AWS site. One 1.5-m tower section was added to the station. A new antenna, a replacement aerovane, and two new boxes of three 40-amphour batteries were installed. The last visit to Lettau site had been in November 1988. At Willie Field AWS site, a Campbell Scientific CR-10 data logger with an Acoustic Depth Gauge (ADG) was installed in support of a science project. The ADG measures the distance to the snow once every 2 hours. An R.M. Young wind system was also installed. An LC-130 flight was taken to Byrd Surface Camp. At the Byrd AWS site a 0.9-m boom with relative humidity and vertical temperature difference was installed. The questionable wind speed sensor Marble Point site was replaced. Mount Howe, Kelly, and Lindsay sites were visited by Twin Otter. The AWS unit at Mount Howe had sustained severe damage from wind, and the ice around the anchors and the tower base had ablated so that the tower was no longer anchored sufficiently. Mount Howe site was removed, as were Kelly and Lindsay, which had been installed in support of a science project. Henry and Nico sites were left in place in the clean air sector to support the Clean Air Facility research at South Pole Station. Clean Air AWS site was moved from its previous location to one approximately 30 m from the South Pole Meteorological tower on 24 January 1994. AWS 8918 was replaced with AWS 8987. A snow temperature profile was installed to a depth of 4 m. The snow temperatures are measured at -4, -2, -1, -0.5, -0.25, -0.0, 0.25, 0.50, 0.75, and 1.0 m relative to the snow surface at the time of installation. Crew members of the U.S. Coast Guard ice breaker Polar Sea flew by helicopter to Whitlock site and replaced AWS 8925 with AWS 8921. Near the Adélie Coast, members of Expeditions Polaires Francaises visited D-80 site on 1 February 1994. Two 1.9-m tower sections were added, as were two boxes of three 40-amp-hour batteries. A new sensor boom and aerovane were installed as well. The crew replaced the existing electronics with a new unit. The ARGOS ID of 8919 was unchanged; however, new pressure calibration data will be provided. On the Antarctic Peninsula, members of the British Antarctic Survey serviced several AWS units during the austral summer. A new AWS 8917 was installed at Sky-Hi site in midFebruary. AWS 8932 was installed at Recovery Glacier. Butler Island (AWS 8902) was serviced and two 1.9-m tower sections were added to Uranus Glacier site. Larsen Ice Shelf site will be serviced at a later date if possible. AWS 8910 was returned to Madison, Wisconsin, for repair. The seawater temperature probe on AWS 8912 at Bonaparte Point was replaced. The removed probe was still working, but the protective conduit was broken. The wire and probe appeared to be in good condition. Members of the Japanese Antarctic Research Expedition had planned to install an AWS unit at Dome F (77.37°S 39.61°E, 4,000 m elevation), but the ship arrived late due to sea ice, so the trip to Dome F was canceled for this season. The AWS program is supported by National Science Foundation grant OPP 93-03569. The British Antarctic Survey
Figure 2. Map showing the locations of the AWS units in the Ross Island area for 1994. • Studies of mesoscale circulation and the sensible and latent heat fluxes on the Ross Ice Shelf; • Climatology studies at Byrd and Dome C Stations; • The Clean Air Facility at the South Pole Station; • Research on Antarctic Coastal Ecosystem Rates expeditions along the Antarctic Peninsula; • Long-Term Ecological Research expeditions along the Antarctic Peninsula; • Flight operations at McMurdo Station; and • Evaluation of meteorological suitability of aircraft landing sites and of possible future station locations. The AWS data starting in 1980 are available at 3-hour intervals on floppy disks. The annual data books contain the 3hour data and monthly summaries. The data are available over Internet at both 3-hour and 10-minute intervals. To obtain the instructions for accessing the data, contact Charles R. Stearns at [email protected] . The original plans for the 1993-1994 field season included a trip to Antarctica for George Weidner and Robert Holmes between 15 November and 15 December 1993 to install eight AWS units on the Siple Coast of West Antarctica, but the trip was canceled because the AWS units were not ready at that time. The Siple Coast AWS units are now planned for installation during the 1994-1995 field season. Weidner and Holmes went to Antarctica in January along with Mark Seefeldt and John Cassano. The Twin Otter aircraft supported us for work on the Ross Ice Shelf and at South Pole Station. Several AWS sites in the McMurdo area suffered damage from the wind storm of 13 June 1993. At the Minna Bluff site, the aerovane had broken off at the mast, and the antenna was damaged. Pegasus North site's aerovane was also damaged. Repairs were made to Minna Bluff, Pegasus North, Willie Field, and Linda AWS sites. Marilyn and Schwerdtfeger sites were visited using the Twin Otter aircraft. Marilyn site was in good condition. The
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installs and services the AWSs in the Antarctic Peninsula area. Expeditions Polaires Françaises installs and services the units along the Adélie Coast. The Japanese Antarctic Research Expedition installs and services those units near the Prince Olav Coast. We were assisted at McMurdo by Naval Support Force Antarctica-Meteorology, Byrd Surface Camp personnel, and the crews of the Twin Otters, U.S. Coast Guard helicopters, and the LC-130s.
References Holmes, R.E., G.A. Weidner, and C.R. Stearns. 1993. Antarctic automatic weather stations: Austral summer 1992-1993. Antarctic Journal of the U.S., 28(5), 296-299. Stearns, C.R., and G.A. Weidner. 1992. Antarctic automatic weather stations: Austral summer 1991-1992, Antarctic Journal of the U.S., 27(5), 280-282.
Antarctic weather forecasting: 1993 CHARLES R. STEARNS and BRUCE B. SINKuLA, Space Science and Engineering Center, University
of Wisconsin,
Madison, Wisconsin 53706
he University of Wisconsin Space Science and Engineering T Center provided daily weather forecasts for the cruises of the RIV Nathaniel B. Palmer, R/V Polar Duke, and Polar Star and for Palmer Station during 1993. Weather information was also sent to the Naval Support Force Antarctica at Christchurch, New Zealand, and McMurdo Station, Antarctica. The most recent weather information available at the Space Science and Engineering Center is the satellite-composite infrared imagery from four geostationary satellites (Meteosat-3, Meteosat-4, GOES-7, and GMS) and two polarorbiting satellites (NOAA-11 and NOAA-12). Composite imagery, constructed every 3 hours, extends from the South Pole to 4005 and provides an overview of the cloud systems around Antarctica. The composite imagery is described by Stearns and Young (1993 and Antarctic Journal, in this issue). National Meteorological Center's medium-range forecast (MRF) gridded model output is available at 0000 universal coordinated time (UTC) and 1200 UTC for the Southern Hemisphere. The five-channel global-area-coverage data from the National Oceanic and Atmospheric Administration's series of polar-orbiting satellites provides imagery of the forecast area. Recent weather observations from the ships and/or stations in Antarctica are available on a daily basis. Most of the automatic weather station data (Holmes, Stearns, and Weidner 1993) are entered into the Global Telecommunications System at 3-hour intervals. These data are ingested by National Meteorological Center and are included in the Southern Hemisphere surface analysis. The forecast operation starts by viewing a series of 3-hour infrared composite images. "Looping" these images allows the forecaster to locate areas of storminess or cyclogenesis occurring over the Southern Hemisphere. The 500-millibar (mb) geopotential height analysis of the MRF model is overlain on the composite imagery. The latest available visual and infrared global-area-coverage imagery is obtained for the area around the forecast position. Accurate satellite interpretation and a good understanding of antarctic meteorology are important skills required of the antarctic weather forecaster. The weather discussion includes details about the current and future state of the weather. Important features from
satellite imagery, automatic weather station observations, and the MRF are highlighted. The forecast product includes graphical images, a weather discussion, and a specific 48hour forecast. The graphical image package available to the user includes the following: an infrared composite satellite image of the Southern Hemisphere; a 0000 UTC Southern Hemisphere 500-mb height analysis; and 12-, 24-, 36-, 48hour MRF mean sea-level pressure forecasts for the ship/station's area of operation. Specific 24-, 36-, and 48-hour forecasts are generated. Wind speed, wind direction, cloud cover, visibility, and significant weather (if any) are the parameters included in the weather forecasts. The weather forecast/discussion is sent directly to the ship or station via electronic mail. The graphical image package is sent (via file transfer protocol) to Antarctic Support Associates; from there, it can be acquired by the ship or station. All forecast products and meteorological data are archived at the University of Wisconsin for forecast verification and case-study analysis. The inconsistent performance of the MRF and sparse conventional data create a challenging weather forecasting environment. Erratic model performance can be attributed to the coarse spacial resolution of the global MRF model and the limited amount of antarctic data available. Knowing what upcoming weather conditions will be is a great help to antarctic personnel as they make logistical decisions for the next couple of days. The research vessel forecast users modify their operations, when possible, to take advantage of the forecasts to increase their scientific activities. The forecasting effort was supported by the National Science Foundation grants OPP 93-03569 and OPP 92-08864.
References Holmes, Robert, C.R. Stearns, and G.A. Weidner. 1993. Antarctic automatic weather stations: Austral summer 1992-1993. Antarctic Journal of the U.S., 28(5), 296-299. Stearns, C.R., and J.T. Young. 1993. Antarctic Meteorological Research Center: 1992-1993. Antarctic Journal of the U.S., 28(5), 335-336. Stearns, C.R., and J.T. Young. 1994. Antarctic Meteorological Research Center 1993. Antarctic Journal of the U.S., 29(5).
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CHARLES R. STEARNS, GEORGE A. WEIDNER,
he National Science Foundation's Office of Polar Proeral experiments, and all contribute to operational purposes T grams places automatic weather station (AWS) units in especially for preparing weather forecasts for aircraft flights to remote areas in Antarctica in support of meteorological and from New Zealand and within Antarctica. research, applications, and operations. Some of the areas supported are the following: The basic AWS units measure air temperature, wind • Barrier wind flow studies along the Antarctic Peninsula speed, and wind direction at a nominal height of 3 meters (m) and in the Transantarctic Mountains; above the surface, and air pressure at the electronics enclo• Katabatic wind flow studies down the slope to the Adélie sure. Some units measure relative humidity at 3 m and the air Coast, Reeves Glacier, Byrd Glacier, and the Beardmore temperature difference between 3 m and 0.5 m above the surGlacier; face at the time of installation. The data are collected by the ARGOS Data Collection System on board the National Oceanic and Atmospheric Administration's series of polar-orbiting satellites. The table gives the AWS " 1994 AWS Sites 70* 60 units' site name, ARGOS identiof 1 March 1994 / as fication number, latitude, longitude, elevation above sea level, Island site start date, and WMO num• -Recovery Glacier 80 ber for the Global Telecommunications System for AWS units in operation as of 1 March 1994. Henry Figure 1 shows the locations of S clean frJr • .Nlco widely spaced AWS units in Antarctica; figure 2 shows the locations on Ross Island. The Byrd Station AWS units are grouped together 80 LettauS • based on the area and are usualDoZ Schwerdtfeger lyfl\ ly related to a single meteorona Bluff sow - - - - - - . Ferrell$ Pegasus North logical experiment in the area. 1 lartle Point Pegasus South;0 Willie Fieldf 4anuela\ Stearns and Weidner (1992) and 120 Sandra Whitlock Holmes, Weidner, and Stearns Ln (1993) describe the AWS activiDenlson Possession lstand• orarn ties during the two previous enguln Point austral summers. I •øVoung Island Scott Island The AWS units are located W 180 150E in arrays for meteorological experiments and at other sites Figure 1. Map of Antarctica showing the locations of widely spaced AWS units for 1994. The Cape Adams for operational purposes. Any AWS site is not shown because the unit could not be found. The Siple Station unit was removed and one AWS may contribute to sev- installed at Ski-Hi. Siple AWS site is decommissioned because of maintenance difficulty.
it4s
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The 1994 antarctic automatic weather station site name, ARGOS identification number, latitude, longitude, altitude above sea level, site start date, and WMO numberfor the Global Telecommunications System
Marble Point Ferrell Pegasus North Pegasus South Minna Bluff Linda Willie Field
Adélie Coast 8914 66.700S 139.800E 240 8916 67.380S 138.720E 1,560 8919 70.020S 134.72°E 2,500 8904 74.500S 123.00°E 3,280 8930 66.820S 141.390E 39 8933 67.020S 142.68°F 31 8929 67.620S 146.00°F 30 West Antarctica 8903 80.00°S 120.00°W 1,530 8981 73.200S 127.05°W 30 Ross Island region 8906 77.430S 163.750E 120 8934 78.020S 170.80°F 45 8927 77.950S 166.51°E 10 8937 78.030S 166.60°F 10 8988b,c 78.560S 166.69°F 920 8915 b 78.500S 168.35°F 50 8901 77.850S 167.08°F 40
Feb 80 89866 Dec 80 89872 Jan 90 89667 Jan 91 Jan 91 89768 Jan 91 89769 Jan 92
Whitlock Scott Island Young Island Possession Island
Ocean islands 8921b 76.240S 168.70°F 275 8983 67.370S 179.97°W 30 8980 66.280S 162.33°F 30 8984 71.900S 171.13°F 30
Jan 82 89865 Dec 87 89371 Dec 90 89660 Dec 92 89879
D-1 0 D-47 D-80 Dome C Port Martin Cape Denison Penguin Point Byrd Station Mount Siple
Ross Ice Shelf 8931 79.980S 165.03°F 75 8913 79.940S 169.83°F 60 8911 80.030S 1 78.63°W 55 8900 83.150S 174.46°F 60 8908C 82.52 0S 174.43°W 55 Reeves Glacier Manuela 8905 74.920S 163.60°F 80 Sandra 8923 74.480S 160.48°F 1,525 Lynn 8935 74.210S 160.39°F 1,772 Antarctic Peninsula Larsen Ice 8926 66.970S 60.55°W 17 Butler Island 8902 72.200S 60.34°W 91 Uranus 8920 71.430S 68.93°W 780 Cape Adams, inactive 75.01 0S 62.53°W 25 Racer Rocks 8947 64.160S 61 .54°W 17 Bonaparte Point 8912 64.780S 63.06°W 8 Recovery Glaciera 8932 80.820S 22.26°F 1,220 SkiHia 8917 74.970S 70.77°W 1,395 Marilyn Schwerdtfeger Gill Elaine Lettau
Feb 80 89832 Jan 83 89834 Nov 84 89836 Feb 80 89828 Jan 90 Jan 90 Dec 93 89847 Feb 80 89324 Feb 92 89327
Jan 84 89869 Jan 85 89868 Jan 85 89863 Jan 86 89873 Jan 86 89377 Feb 84 89864 Jan 88 89861 Jan 88 89860 Oct 85 89262 Mar 86 89266 Mar 86 89264 Jan 89 89268 Nov 89 89261 Nov 91 89269 Jan 94 Feb 94
High polar plateau Clean Air 8987b 90.00°S 2,835 Jan 86 89208 Henry 8985 89.00°S 0.30°W 2,755 Jan 93 89108 Nico 8924 89.00°S 90.13°F 2,935 Jan 93 89799 a New locations for 1994 bNew ARGOS ID at the site for 1994 C New latitude and/or longitude based on aircraft global positioning system
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malfunctioning aerovane at Schwerdtfeger site was replaced. A Twin Otter flight was made to Lettau AWS site. One 1.5-m tower section was added to the station. A new antenna, a replacement aerovane, and two new boxes of three 40-amphour batteries were installed. The last visit to Lettau site had been in November 1988. At Willie Field AWS site, a Campbell Scientific CR-10 data logger with an Acoustic Depth Gauge (ADG) was installed in support of a science project. The ADG measures the distance to the snow once every 2 hours. An R.M. Young wind system was also installed. An LC-130 flight was taken to Byrd Surface Camp. At the Byrd AWS site a 0.9-m boom with relative humidity and vertical temperature difference was installed. The questionable wind speed sensor Marble Point site was replaced. Mount Howe, Kelly, and Lindsay sites were visited by Twin Otter. The AWS unit at Mount Howe had sustained severe damage from wind, and the ice around the anchors and the tower base had ablated so that the tower was no longer anchored sufficiently. Mount Howe site was removed, as were Kelly and Lindsay, which had been installed in support of a science project. Henry and Nico sites were left in place in the clean air sector to support the Clean Air Facility research at South Pole Station. Clean Air AWS site was moved from its previous location to one approximately 30 m from the South Pole Meteorological tower on 24 January 1994. AWS 8918 was replaced with AWS 8987. A snow temperature profile was installed to a depth of 4 m. The snow temperatures are measured at -4, -2, -1, -0.5, -0.25, -0.0, 0.25, 0.50, 0.75, and 1.0 m relative to the snow surface at the time of installation. Crew members of the U.S. Coast Guard ice breaker Polar Sea flew by helicopter to Whitlock site and replaced AWS 8925 with AWS 8921. Near the Adélie Coast, members of Expeditions Polaires Francaises visited D-80 site on 1 February 1994. Two 1.9-m tower sections were added, as were two boxes of three 40-amp-hour batteries. A new sensor boom and aerovane were installed as well. The crew replaced the existing electronics with a new unit. The ARGOS ID of 8919 was unchanged; however, new pressure calibration data will be provided. On the Antarctic Peninsula, members of the British Antarctic Survey serviced several AWS units during the austral summer. A new AWS 8917 was installed at Sky-Hi site in midFebruary. AWS 8932 was installed at Recovery Glacier. Butler Island (AWS 8902) was serviced and two 1.9-m tower sections were added to Uranus Glacier site. Larsen Ice Shelf site will be serviced at a later date if possible. AWS 8910 was returned to Madison, Wisconsin, for repair. The seawater temperature probe on AWS 8912 at Bonaparte Point was replaced. The removed probe was still working, but the protective conduit was broken. The wire and probe appeared to be in good condition. Members of the Japanese Antarctic Research Expedition had planned to install an AWS unit at Dome F (77.37°S 39.61°E, 4,000 m elevation), but the ship arrived late due to sea ice, so the trip to Dome F was canceled for this season. The AWS program is supported by National Science Foundation grant OPP 93-03569. The British Antarctic Survey
Figure 2. Map showing the locations of the AWS units in the Ross Island area for 1994. • Studies of mesoscale circulation and the sensible and latent heat fluxes on the Ross Ice Shelf; • Climatology studies at Byrd and Dome C Stations; • The Clean Air Facility at the South Pole Station; • Research on Antarctic Coastal Ecosystem Rates expeditions along the Antarctic Peninsula; • Long-Term Ecological Research expeditions along the Antarctic Peninsula; • Flight operations at McMurdo Station; and • Evaluation of meteorological suitability of aircraft landing sites and of possible future station locations. The AWS data starting in 1980 are available at 3-hour intervals on floppy disks. The annual data books contain the 3hour data and monthly summaries. The data are available over Internet at both 3-hour and 10-minute intervals. To obtain the instructions for accessing the data, contact Charles R. Stearns at [email protected] . The original plans for the 1993-1994 field season included a trip to Antarctica for George Weidner and Robert Holmes between 15 November and 15 December 1993 to install eight AWS units on the Siple Coast of West Antarctica, but the trip was canceled because the AWS units were not ready at that time. The Siple Coast AWS units are now planned for installation during the 1994-1995 field season. Weidner and Holmes went to Antarctica in January along with Mark Seefeldt and John Cassano. The Twin Otter aircraft supported us for work on the Ross Ice Shelf and at South Pole Station. Several AWS sites in the McMurdo area suffered damage from the wind storm of 13 June 1993. At the Minna Bluff site, the aerovane had broken off at the mast, and the antenna was damaged. Pegasus North site's aerovane was also damaged. Repairs were made to Minna Bluff, Pegasus North, Willie Field, and Linda AWS sites. Marilyn and Schwerdtfeger sites were visited using the Twin Otter aircraft. Marilyn site was in good condition. The
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installs and services the AWSs in the Antarctic Peninsula area. Expeditions Polaires Françaises installs and services the units along the Adélie Coast. The Japanese Antarctic Research Expedition installs and services those units near the Prince Olav Coast. We were assisted at McMurdo by Naval Support Force Antarctica-Meteorology, Byrd Surface Camp personnel, and the crews of the Twin Otters, U.S. Coast Guard helicopters, and the LC-130s.
References Holmes, R.E., G.A. Weidner, and C.R. Stearns. 1993. Antarctic automatic weather stations: Austral summer 1992-1993. Antarctic Journal of the U.S., 28(5), 296-299. Stearns, C.R., and G.A. Weidner. 1992. Antarctic automatic weather stations: Austral summer 1991-1992, Antarctic Journal of the U.S., 27(5), 280-282.
Antarctic weather forecasting: 1993 CHARLES R. STEARNS and BRUCE B. SINKuLA, Space Science and Engineering Center, University
of Wisconsin,
Madison, Wisconsin 53706
he University of Wisconsin Space Science and Engineering T Center provided daily weather forecasts for the cruises of the RIV Nathaniel B. Palmer, R/V Polar Duke, and Polar Star and for Palmer Station during 1993. Weather information was also sent to the Naval Support Force Antarctica at Christchurch, New Zealand, and McMurdo Station, Antarctica. The most recent weather information available at the Space Science and Engineering Center is the satellite-composite infrared imagery from four geostationary satellites (Meteosat-3, Meteosat-4, GOES-7, and GMS) and two polarorbiting satellites (NOAA-11 and NOAA-12). Composite imagery, constructed every 3 hours, extends from the South Pole to 4005 and provides an overview of the cloud systems around Antarctica. The composite imagery is described by Stearns and Young (1993 and Antarctic Journal, in this issue). National Meteorological Center's medium-range forecast (MRF) gridded model output is available at 0000 universal coordinated time (UTC) and 1200 UTC for the Southern Hemisphere. The five-channel global-area-coverage data from the National Oceanic and Atmospheric Administration's series of polar-orbiting satellites provides imagery of the forecast area. Recent weather observations from the ships and/or stations in Antarctica are available on a daily basis. Most of the automatic weather station data (Holmes, Stearns, and Weidner 1993) are entered into the Global Telecommunications System at 3-hour intervals. These data are ingested by National Meteorological Center and are included in the Southern Hemisphere surface analysis. The forecast operation starts by viewing a series of 3-hour infrared composite images. "Looping" these images allows the forecaster to locate areas of storminess or cyclogenesis occurring over the Southern Hemisphere. The 500-millibar (mb) geopotential height analysis of the MRF model is overlain on the composite imagery. The latest available visual and infrared global-area-coverage imagery is obtained for the area around the forecast position. Accurate satellite interpretation and a good understanding of antarctic meteorology are important skills required of the antarctic weather forecaster. The weather discussion includes details about the current and future state of the weather. Important features from
satellite imagery, automatic weather station observations, and the MRF are highlighted. The forecast product includes graphical images, a weather discussion, and a specific 48hour forecast. The graphical image package available to the user includes the following: an infrared composite satellite image of the Southern Hemisphere; a 0000 UTC Southern Hemisphere 500-mb height analysis; and 12-, 24-, 36-, 48hour MRF mean sea-level pressure forecasts for the ship/station's area of operation. Specific 24-, 36-, and 48-hour forecasts are generated. Wind speed, wind direction, cloud cover, visibility, and significant weather (if any) are the parameters included in the weather forecasts. The weather forecast/discussion is sent directly to the ship or station via electronic mail. The graphical image package is sent (via file transfer protocol) to Antarctic Support Associates; from there, it can be acquired by the ship or station. All forecast products and meteorological data are archived at the University of Wisconsin for forecast verification and case-study analysis. The inconsistent performance of the MRF and sparse conventional data create a challenging weather forecasting environment. Erratic model performance can be attributed to the coarse spacial resolution of the global MRF model and the limited amount of antarctic data available. Knowing what upcoming weather conditions will be is a great help to antarctic personnel as they make logistical decisions for the next couple of days. The research vessel forecast users modify their operations, when possible, to take advantage of the forecasts to increase their scientific activities. The forecasting effort was supported by the National Science Foundation grants OPP 93-03569 and OPP 92-08864.
References Holmes, Robert, C.R. Stearns, and G.A. Weidner. 1993. Antarctic automatic weather stations: Austral summer 1992-1993. Antarctic Journal of the U.S., 28(5), 296-299. Stearns, C.R., and J.T. Young. 1993. Antarctic Meteorological Research Center: 1992-1993. Antarctic Journal of the U.S., 28(5), 335-336. Stearns, C.R., and J.T. Young. 1994. Antarctic Meteorological Research Center 1993. Antarctic Journal of the U.S., 29(5).
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