Alaska, North Slope: projects/activities

More information about the following long-term observing activities will be available in due course

To collect contemporary data on shorebird demography and to compare these data to historic information collected at the site. We are attempting to establish an Arctic Shorebird Demography Network patterned after the Barrow site. This is only at the beginning stages.

To conserve the federally listed Alaska-breeding population of Steller’s eiders through monitoring breeding, surveying populations, predator management, and analyzing the effects of management actions. Main gaps: We are only collecting data on the breeding biology of this species along the road system near Barrow, Alaska.

Examine temporal and spatial variation in trace metal concentrations in the western Arctic through the analysis of Black Guillemot feathers. Temporal trends being examined using study skins collected as early as 1897. Spatial variation examined in conjunction with carbon isotope signatures in feathers and by sampling both winter and summer plumages. Regional climate change monitored through examination of annual variation in breeding chronology and success in relation to snow and ice melt.

Contaminants were examined for trends over time, spatial variation based on disparate breeding areas, and relationships with measures of productivity. Most organochlorines and metals declined over time. Mercury was the only contaminant with possibly increasing concentrations in eggs. Egg and feather samples collected in 2000 will provide more information on mercury trends and effects. This study embodies 20 years of data on environmental contaminants in peregrine falcons nesting in Alaska.

The overall project outlined in this proposal represents a series of interrelated studies designed to answer questions regarding the effects of disturbance on distribution and abundance of waterfowl and marine birds. The primary studies (i.e., aerial surveys) are directly related to the objectives identified in the Minerals Management Service (MMS) Statement-of-work regarding Monitoring Beaufort Sea Waterfowl and Marine Birds near the Prudhoe Bay Oil Field, Alaska. Additionally, we plan to include the ‘optional’ studies on eiders using off-shore barrier island habitats. Finally, we propose to conduct ground based studies designed to enhance and expand the interpretation of the aerial surveys. The specific objectives of this study are: 1. Monitor Long-tailed Duck and other species within and among industrial and control areas in a manner that will allow comparison with earlier aerial surveys using Johnson and Gazeys’ (1992) study design. a) Perform replicate aerial surveys of five previously established transects based on existing protocol (OCS-MMS 92-0060). b) Expand the area from original surveys to include near-shore areas along Beaufort Sea coastline between the original “industrial” (Jones-Return Islands) and “control” (Stockton-Maguire-Flaxman Islands) areas. c) Define the range of variation for area waterfowl and marine bird populations. Correlate this variation with environmental factors and oil and gas exploration, development, and production activities. 2. Expand aerial monitoring approximately 50 km offshore. Surveys will target Spectacled, Common and King eiders. The goal is to sample areas potentially impacted by oil spills from the Liberty, Northstar, and/or Sandpiper Units. 3. Develop a monitoring protocol for birds breeding on barrier islands, particularly Common Eiders. These data will be compared to historic data summarized by Schamel (1977) and Moitoret (1998). 4. Examine relationships between life-history parameters (e.g., fidelity, annual survival, productivity) and ranges of variation in Long-tailed Ducks and Common Eider distribution and abundance to enhance interpretation of cross-seasonal effects of disturbance. That is, the combination of aerial and ground based work has the potential to both document changes in abundance/distribution and describe those changes in terms of movements of marked individuals. Parameters will be examined in relation to disturbance using the two-tiered approach developed by Johnson and Gazey (1992). 5. Recommend cost-effective and feasible options for future monitoring programs to evaluate numbers and species of birds potentially impacted by oil spills involving ice-free and ice periods in both inshore and offshore waters.

We compared animals from a caribou (Rangifer tarandus) mortality event in the area of Point Hope and Chariot (Cape Thompson), Alaska (USA) in 1995 to hunter-killed caribou from reference sites (Barrow, Red Dog Mine, and Teshekpuk Lake, Alaska). Gross and histologic endpoints, and element levels (As, Cd, Cu, Pb, Zn, Fe) were evaluated. Starvation/malnutrition were major factors leading to death or severe weakness as very little or no fat (very low body condition scores) and serous atrophy of fat (marrow cavity and histologically) were more prevalent in caribou associated with the mortality event as compared to reference sites animals. Accumulation of hepatic hemosiderin in Kuppfer cells was noted as an indicator of cachexia. Levels of lead in feces and liver, copper the rumen contents, and arsenic in muscle were higher in caribou harvested near Red Dog Mine and might be expected in the mineral rich area, but were not at a level of concern for toxicoses. Kidney levels of cadmium were significantly increased with increasing age, and presents a potential concern for human consumers, and is an expected finding. We concluded that heavy metals played no role in the mortality event and that caribou starved. Further investigation of regional minerals differences is required to understand the sources and transport mechanisms to explain these findings and to properly address mining activity impacts. Mortality events on the north slope of Alaska are not uncommon and likely involve starvation as described here, but in most cases are not investigated, even though recent industrial activities have heightened concern.

White whale (Delphinapterus leucas) blubber samples from three of the five different Alaskan stocks - Cook Inlet (n = 20), Eastern Chukchi Sea (n = 19) and Eastern Beaufort Sea (n = 2) - were analyzed for levels and patterns of chemical contaminants. Blubber of these whales contained sum PCBs, sum DDTs, sum chlordanes, HCB, dieldrin, mirex, *toxaphene and *HCH, generally in concentration ranges similar to those found in white whales from the Canadian Arctic and lower than those in white whales from the highly contaminated St. Lawrence River. The males of the Cook Inlet and Eastern Chukchi Sea stocks had higher mean concentrations of all contaminant groups than did the females of the same stock, a result attributable to the transfer of these organochlorine contaminants (OCs) from the mother to the calf during pregnancy and during lactation following birth. Principal components analysis of patterns of contaminants present in blubber showed that Cook Inlet stock appeared to have identifiable contaminant patterns that allowed the stock to be distinguished from the others. Our results also showed that blubber from the three Alaskan stocks was a source of contaminant exposure for human subsistence consumers, but the health risks from consumption are currently unknown.

Blubber samples from Alaska ringed seal (Phoca hispida) were collected for inclusion in the US National Biomonitoring Specimen Bank, as well as for immediate analysis as part of the contaminant monitoring component of the US National Marine Fisheries Service's Marine Mammal Health and Stranding Response Program. The blubber samples were analyzed for organochlorine (OC) contaminants (e.g., PCB congeners, pesticides, DDTs). Results for ringed seals from the Alaska Arctic revealed low blubber concentrations of OC contaminants. Differences in contaminant concentrations among the Alaska seals may be explained by differences in feeding habits and migratory patterns; age or gender did not appear to account for the differences observed. The integration of real-time contaminant monitoring with specimen banking provides important baseline data that can be used to plan and manage banking activities. This includes identifying appropriate specimens that are useful in assessing temporal trends and increasing the utility of the banked samples in assessing chemical contaminant accumulation and relationships to biological effects.

1. Sediment study for heavy metals and selected organic contaminants. 2. Analysis of benthic organisms for heavy metals and selected organic contaminants. 3. Study of suspended sediment distribution, composition and sources. 4. Determination of partitioning of heavy metals between dissolved and particulate phases.

I. Objectives: I.1. To determine the normal range of values (natural variability due to time of year, age, gender) for basic nutritional and health parameters (blubber characteristics, essential and non-essential elements, structure of basic tissues) in the bowhead whale. a. Blubber thickness (depth and girth), chemical composition (lipids, water, calories), and tissue structure (light microscopy and special stains) will be assessed. b. Essential and non-essential elements (heavy metals) will be measured in liver and kidney. c. Tissue structure (light microscopy) characteristics obviously related to nutritional status in liver (glycogen, lipid and lipofuscin stores), pancreas (zymogen granules), and intestine (mucosal microvilli) and any evidence of inactivity/atrophy will be examined. d. Documentation of "normal" structure of basic tissues and evaluation for evidence of disease will also be conducted. I.2. Using data from Objective 1 to identify the parameters most important in assaying the health status of other mysticetes residing in the Bering Sea or Western Arctic that are harvested or stranded. I.3. Using data from Objective 1 to help determine the role of the bowhead whale as an indicator of ecosystem health and development of an optimized protocol for assessing mysticete health for the Bering Sea and Western Arctic, and other regions.

1. Research area # 2 in the 1998/99 Announcement of Opportunity by CIFAR, "Study of anthropogenic influences on the Western Arctic/Bering Sea Ecosystem", and 2. Research area #4 in the 1998/99 Announcement of Opportunity by CIFAR, "Contaminant inputs, fate and effects on the ecosystem" specifically addressing objectives a-c, except "effects." a. "Determine pathways/linkages of contaminant accumulation in species that are consumed by top predators, including humans, and determine sub-regional differences in contaminant levels..." b. "Use an ecosystems approach to determine the effects of contaminants on food web and biomagnification." c. "Encourage local community participation in planning and implementing research strategies." The objectives of Phase I, Human Ecology Research are to: 1. Document reliance by indigenous arctic marine communities in Canada, Alaska and Russia on arctic resources at risk from chemical pollutants; and, 2. Incorporate traditional knowledge systems of subsistence harvesting. The human ecology components of the project were conducted within the frameworks of indigenous environmental knowledge and community participation. Using participatory mapping techniques, semi-structured interviews and the direct participation of community members in research design, data collection and implementation, research and data collection on the human ecology of indigenous arctic marine communities was undertaken in the communities of Holman, NWT (1998), Wainwright, Alaska (1999), and is underway in Novoe Chaplino, Russia. (2000).

The first part of the present study evaluated tissue concentrations of twelve essential and non-essential elements in four arctic marine mammal species important as subsistence resources to indigenous Alaskans. Species sampled included: bowhead whales, beluga whales, ringed seals, and polar bears. Concentrations of As, Cd, Co, Cu, Pb, Mg, Mn, Hg, Mo, Se, Ag, and Zn, were analyzed in liver, kidney, muscle, blubber, and epidermis (the latter in cetaceans only). Elements that were identified as having tissue concentrations, which in domesticated species would have been considered higher than normal and/or even toxic, were Cd, Hg, Ag, and Se. However, the concentrations of these elements were consistent with previous reports for arctic marine mammals. Remaining elements were at concentrations within normal ranges for domesticated species, although Cu was found frequently at concentrations that would be considered marginal or deficient in terrestrial domesticated animals. Across-species comparisons revealed that Cd was highest in kidney, followed by liver in all four species. Its concentrations were frequently correlated with Cu, Zn, Hg, and Se. Cadmium accumulated with age in bowhead and beluga whales, especially in liver and kidney. The relationships between Cd and Hg, and between Cd and Se were believed to be due to mutual accretion with age, although direct interactions could not be ruled out, especially with respect to Cd and Se. Associations between Cd and Cu, and Cd and Zn were potentially attributable to mutual binding with the inducible protein, metallothionein. This assumption was supported by the observation that Cd:Zn ratios in liver and kidney displayed a significant linear relationship to age and that this ratio either increased slightly (in kidney and liver of bowheads) or remained constant (in kidney and liver of belugas) with age. In general, Se was highest in liver and kidney of all four species, where it was frequently at concentrations that would have been deemed elevated or toxic for domesticated species, although within ranges previously reported for arctic marine mammals. Selenium increased with age indices, and was highly correlated with Hg, and often with Cd as well. Mercury also increased with age, and liver contained the highest tissue concentration in the cetacean and pinniped species. The pattern of Se accumulation in polar bears differed, with highest concentrations found in kidney, which suggested that this tissue may be the primary site for Hg detoxification in this species, as is the case for terrestrial mammals. Compared to the other three species, bowhead whales had very low Hg concentrations in all tissues. The highly significant linear relationship between Hg and Se noted in various tissues (particularly liver) of all four species was presumed due to binding of these two elements to each other following demethylation of MHg. This assumption was supported by the observations that while Se and Hg both accumulated with age, the fraction of total Hg that was composed of MHg decreased with age. The quantity that represented the difference between total Hg measured directly and calculated total Hg [i.e., SHg = Hg(II) + MHg], also increased with age in beluga liver. This connoted that a portion of the total Hg present was in an organic form other than MHg, and that this form accumulated with age. Alternatively, this portion, which was apparently not measured by either the Hg(II) or MHg procedures, may have been lost during extraction. Species in this study had mean hepatic Hg:Se molar ratios that were below unity. This implies that Hg concentrations may have been below some threshold level, after which subsequent accumulation proceeds in a 1:1 molar ratio fashion with Se. Alternatively, it might suggest that a 1:1 Hg:Se molar ratio is not a prerequisite for protection from Hg toxcosis among marine mammals, because none of the animals in the present study exhibited lesions typically associated with Hg toxicosis. In beluga liver, concentrations of Ag were elevated when compared to domesticated species. The only element that showed a significant linear association to Ag was Cu—a relationship that was observed in all four species. This suggested that Ag and Cu may be associated through a common ligand, possibly metallothionein. The association between Ag and Se in beluga liver was less strong than that between Hg and Se; moreover, Ag did not increase with age. These findings indicate that Ag probably does not compete with Hg for Se binding, and therefore is unlikely to substantially inhibit detoxification of Hg in beluga whales. In the second portion of this research, tissues from bowhead whales, beluga whales and ringed seals were examined at both the gross and light microscopic level. The purpose of this evaluation was three-fold: to describe the normal histologic appearance of tissues; to perform a routine histologic survey of tissues that would contribute to a general health assessment, and; to scrutinize tissues for lesions that might support a diagnosis of toxicosis caused by Cd, Hg, Ag, or Se. Tissues examined were chosen on the basis of their propensity to be targets for toxicologic injury from the specified elements (with the exception of brain) and included, but were not limited to, the tissues analyzed chemically. Special stains were used to identify particular pigments or tissue components. Overall, the bowhead whales evaluated appeared healthy and had low parasite burdens. The most common lesion, which was observed in all bowheads, was a non-inflammatory chronic renal periglomerular and interstitial fibrosis. This lesion was not typical of Cd-induced nephropathy, and it did not appear to be associated with renal Cd burdens. Nevertheless, thresholds of Cd-induced renal injury are not known for cetacean species, and more whales need to be examined histologically in conjunction with analysis of tissue Cd residues. Acute myodegeneration was observed in cardiac and/or skeletal muscle of a few bowheads, and was presumed to reflect a hunting-induced exertional myopathy. The beluga whales examined were generally in good body condition and appeared healthy grossly, but they had much higher parasite burdens than bowhead whales. In particular, prevalence in belugas of pulmonary nematodiasis was high, being especially common among whales obtained from Pt. Hope compared to those from Pt. Lay. Grossly, firm, caseous nodules were associated with lungworms, while histologically, the associated pulmonary changes ranged from mild chronic inflammation and focal granuloma formation to catarrhal granulomatous and eosinophilic verminous bronchopneumonia. Another change observed in some belugas and believed to be associated with lungworm infection, was multifocal pulmonary arterial medial hypertrophy and degeneration. Beluga whales harvested at Pt. Lay (summer) frequently showed evidence of hepatic and pancreatic atrophy, while whales taken at Pt. Hope (spring) did not. This was believed to result from anorexia during migration—a supposition corroborated by the lack of stomach contents among Pt. Lay whales. Another prominent histologic finding among belugas was hepatic telangectasia, which occurred with significantly greater frequency and severity in Pt. Hope belugas than in those from Pt. Lay. The etiology and significance of this lesion could be not be ascertained, although it was not believed to be associated with any of the elements analyzed in this study. Mild thickening of Bowman’s capsule was seen frequently in belugas. However, this lesion was not typical of Hg or Cd-induced nephropathies, and did not appear correlated with kidney concentrations of these metals. This lesion was believed to be a normal consequence of aging in belugas, although a metal etiology for it could not be excluded irrefutably. In general, ringed seals were in good body condition and appeared healthy on gross examination. Among seals evaluated histologically, the most common finding was a mild, chronic, focal or periportal hepatitis, with focal hepatocellular necrosis sometimes apparent. Although a metal etiology for this lesion could not be definitively ruled out, in the absence of other lesions that would support a diagnosis of metal toxicosis, an infectious etiology was considered more credible. Two out of sixteen seals had embryologic remnants (an epidermoid cyst and an ultimobranchial cyst)—lesions that are usually considered incidental. While no toxic (metal or otherwise) etiology could be ascertained for these lesions, the incidence of retained embryologic remnants seemed high. A number of xenobiotics are known to be endocrine-disruptors, and the potential for such an etiology among these seals should be examined further. Lipofuscin deposition was ubiquitous among all three species examined histologically. Lipofuscin was most prevalent in hepatocytes, but also commonly was observed in various other tissue and cell types, especially in cardiac and skeletal myocytes, and in uriniferous tubular epithelial cells. The third portion of this study employed autometallographic (AMG) development of light microscopic tissue sections to amplify and localize deposition of inorganic Hg in liver and kidney of beluga and bowhead whales. No staining occurred among bowhead tissues, confirming the extremely low concentration of Hg determined through chemical analyses. In beluga kidney sections, AMG granules were seen throughout the uriniferous tubular epithelium, showing that Hg deposits throughout the nephric tubule, and not solely in the proximal tubular epithelium. In liver tissue, AMG granules were deposited primarily in periportal regions among whales with lower hepatic Hg burdens. In addition to periportal deposition, AMG granules were observed in pericentral and mid-zonal regions in the belugas sampled that had higher liver Hg concentrations (generally older animals). Granules were densely concentrated in stellate macrophages, especially near portal triads. Granules also were distributed in hepatocellular cytoplasm, generally concentrated toward the bile cannalicular domain of the cell. Granules were discrete, potentially indicating that Hg was confined within lysosomes. These observations suggested that inorganic Hg deposits initially in periportal regions of young animals, with subsequent accumulation occurring pericentrally, and finally, midzonally as the whales age. Computer-assisted densitometric analysis was used for semi-quantitative evaluation of AMG staining intensities. These AMG staining intensities were well correlated with concentrations of Hg determined via chemical analysis. Areas with AMG-staining were identified and compared with location of lipofuscin in the same field, visualized with fluorescent microscopy. While AMG granules and lipofuscin deposits sometimes were co-localized, they more often were not. In addition, abundant lipofuscin deposition was seen in livers of younger belugas with little to no Hg-catalyzed AMG staining. Also, lipofuscin concentrated predominantly in pericentral regions. These observations suggested that in the healthy marine mammals of this study, marked hepatic lipofuscin deposition most often occurred independently of Hg accumulation. Consequently, hepatic lipofuscin is likely to be a poor indicator of Hg-induced damage in belugas. The abundant lipofuscin deposition in livers of marine mammals was interpreted as most likely denoting a heightened exposure to oxidative stress that is probably inherent to a marine mammalian existence. These oxidative stressors may include a diet high in polyunsaturated fatty acids (PUFAs), alternating hypoxia and abundant oxygenation, and periodic bouts of anorexia associated with migration.

We conducted gamma spectrometric analyses on more than 200 arctic marine mammal tissue samples. These samples were primarily provided by subsistence hunters from northern Alaska, with a smaller number of samples from the Resolute region in Canada. The majority of samples (>90% ) had detectable levels of the anthropogenic radionuclide 137Cs, with a mean level observed in all samples of 0.67 Bq kg-1 dry weight ±0.81 (SD). Converted to wet weight, the mean was 0.21 Bq kg-1 ±0.19 SD. The median activity observed was 0.45 Bq kg-1 dry weight (0.18 Bq kg-1 wet weight) with a range from detection limits to 6.7 Bq kg-1dry weight (1.1 Bq kg-l wet weight). These findings confirm expectations that current anthropogenic gamma emitter burdens in marine mammals used in the North American Arctic as subsistence food resources are well below activities that would normally merit public health concern (~1000 Bq kg-1 wet weight). Some differences among species and tissues were observed. Beluga tissues had slightly higher mean burdens of 137Cs overall, and epidermis and muscle tissues in bowhead and beluga whales typically had higher burdens than other tissues analyzed. Low levels of the neutron activation product l08mAg (half-life 418 yr.), probably bioaccumulated from bomb fallout sources, were observed in 16 of 17 beluga livers analyzed, but were not found in any other tissues of beluga or in any other species sampled. A subset of 39 samples of various tissues was analyzed for the alpha and beta emitters 239,240Pu and 90Sr. Plutonium levels were near the threshold of detectability (~0.1 Bq kg-1 dry weight) in 6 of the 39 samples; all other samples had no detectable plutonium. A detectable level of 90Sr (10.3 ±1.0 Bq kg-1 dry weight) was observed in only one of the 39 samples analyzed, a bowhead epidermis sample. Although the accumulation of 108mAg has not been previously reported in any marine mammal livers, all of our analytical measurements indicate that only very low levels of anthropogenic radioactivity are associated with marine mammals harvested and consumed in the North American Arctic.

Moose (Alces alces) found dead (FD) and hunter-killed (HK) in 1995 on the north slope of Alaska (Colville River drainage) were evaluated for heavy metal and mineral status. Compared to previous reports for moose and domestic cattle, and data presented here from Alaska moose outside the Colville River area, levels of copper (Cu) were determined to be low in hoof, hair, liver, kidney, rumen contents, and muscle for these north slope moose. Iron (Fe) was low in muscle as well. These findings, in conjunction with evidence of poor calf survival and adult mortality prompted investigation of a mineral deficiency in moose (serum, blood, and hair) captured in the spring of 1996 and 1997. Captured males had higher Ca, Zn and Cu levels in hair than captured females. Female moose hair samples were determined to be low (deficient) in Cu, Ca, Fe, and Se with mean levels (ppm) of 2.77, 599.7, 37.4, and 0.30, respectively. Serum Cu level was low, and to a lesser degree Zn was deficient as well. Whole blood (1997 only) was marginally deficient in Se and all animals were deficient in Cu. Based on whole blood, sera and hair, Cu levels were considered low for moose captured in spring 1996 and 1997 in the Colville River area as compared to published data and other populations evaluated in this study. Low levels of ceruloplasmin activity support this Cu deficiency theory. Evidence indicates that these moose are deficient in Cu and other minerals; however, the remote location precluded sufficient examination of animals to associate this apparent deficiency with direct effects or lesions. Renal levels of Cd increased with age at expected levels.

This research consists of eight projects. 1. Climate-related remote sensing of clouds. A project to extend and test innovative techniques for observing cloud microphysical properites from ground-based cloud radar, lidar, and radiometers (P.I. Brooks Martner +1-303-497-6375) 2. Ground-based and remote sensing of microphysical and radiative properties of Arctic clouds. This project involves data analysis of radar, lidar, and radiometer data from the FIRE-III Arctic Cloud Experiment, including in situ validation with aircraft, and development of retrieval techniques of cloud microphysical properties from satellite data. (P.I. Taneil Uttal, +1-303-497-6409) 3. Deployment of surface based, active remote sensors during SHEBA. Data collected in 1997-1998 will be analyzed to provide information on cloud boundaries, radar reflectivities, radar Doppler velocities, lidar depolarization ratios, and lidar backscatter. (P.I. Taneil Uttal, +1-303-497-6409) 4. Validation of CERES cloud retrievals over the Arctic with surface-based millimeter-wave radar. The goal is to provide long-term data sets to validate satellite data from the CERES package on the TERRA satellite. (P.I. Taneil Uttal, +1-303-497-6409) 5. Development of an integrated sounding system in support of the DOE/ARM program. Microwave and millimeter wave radar data sets are being collected to study water vapor and Arctic clouds under Arctic winter conditions. (P.I. Ed Westwater, +1-303-497-6527) 6. Application of Kalman filtering to derive water vapor profiles from combined ground-based sensors. The goal is to improve calibration methods for the ARM microwave radiometers. (P.I. Ed Westwater, +1-303-497-6527) 7. Meltpond 2000. The goal is to use aircraft-based radiometers to obtain the first high spatial resolution microwave images of polynas to improve the interpretation of SSM/I and SSMIS imagery of Arctic ice. (P.I. Al Gasiewski, +1-303-497-3577) 8. Arctic atmospheric radiation studies. This collaboration with the Japanese Communications Research Laboratory provides for ground-based measurement of ozone, water vapor and cloud radiation. (P.I. Joe Shaw, +1-303-497-6496)

The North Slope of Alaska/Adjacent Arctic Ocean Cloud and Radiation Testbed (CART) site is providing data about cloud and radiative processes at high latitudes. These data are being used to refine models and parameterizations as they relate to the Arctic. The NSA/AAO site is centered at Barrow and extends to the south (to the vicinity of Atqasuk), west (to the vicinity of Wainwright), and east (perhaps to Oliktok). The Adjacent Arctic Ocean was probed by the Surface Heat Budget of the Arctic (SHEBA) experiment, a multi-agency program led by the National Science Foundation and the Office of Naval Research. SHEBA involved the deployment of an instrumented ice camp within the perennial Arctic Ocean ice pack that began in October 1997 and lasted for 12 monthsB. For the planning period covered here, a major focus will be on completing the facilities at Atqasuk, 100 km inland from Barrow. Presently, the instrumentation shelters are located on a gravel pad turn-around at the end of a dead end road between the town of Atqasuk and its airport. To comply with the terms of our land lease, we will construct a platform on pilings adjacent to the gravel pad and move the shelters off the roadway and onto the platform. The platform will permit long-term deployment of the Atqasuk instrumentation in a manner very similar to that at Barrow. Sky radiation (SKYRAD) radiometric instrumentation will be mounted above the level of the roof of the shelters so as to avoid shadowing, and the ground radiation (GNDRAD) instrumentation will be mounted on a tip tower such as the one about to be installed at Barrow. At Atqasuk, during the CY 2000 melt season, the science team heat flux study begun during the CY 1999 melt season will resume in spring with the redeployment of a laser scintillometer. In addition, heat flux measurements will begin near Barrow on the shore of the Beaufort Sea in the same time frame. Also at Barrow, a mini-IOP is planned during spring 2000 that will bring together two extended-range atmospheric emitted radiance interferometers (ER-AERIs) (including the one permanently installed at Barrow), one normal range downward-looking AERI (for snow characterization), and one or two other extended-range upward-looking Fourier transform infrared spectrometers (FTIRs). Various other less major enhancements will be made to the instrumentation suites of both Barrow and Atqasuk. Both facilities, however, will continue to be strongly focused on Instantaneous Radiative Flux (IRF) experiments for this planning period. A Single-Column Model (SCM) experiment utilizing either subscale or full scale aircraft that had been proposed for the NSA/AAO for CY2000 will be put off for a year.