Daily weather data from mid May to late July 2011 to 2013 from Roche Moutonnee (south of Toolik Field Station and Arctic LTER), in the northern foothills of the Brooks Range, Alaska. Parameters measured include: wind speed, wind directions, temperature, humidity, pressure and precipitation.
Data Set Results
Weekly Normalized Difference Vegetation Index (NDVI) data from Roche Moutonnee, Toolik Lake Field Station, Imnavait Creek and Sagavanirktok River DOT sites in the northern foothills of the Brooks Range, Alaska. Located south of the Arctic LTER and Toolik Lake Field Station. Data collected from May to July 2010-2014. Methods and further data published in Ecography by Rich, et al. 2013.
Daliy weather data from mid May to late July 2011 to 2013 from Sagavanirktok Department of Transport (DOT) site (south of Toolik Field Station and Arctic LTER), in the northern foothills of the Brooks Range, Alaska. Parameters measured include: wind speed, wind directions, temperatrue, humididty, pressure and precipitation. (Rich, et al 2013).
Daily landscape-level snow cover percent data from Toolik Lake Field Station (TFS), Imnavait (IMVT), and the Sagavanirktok River DOT site (SDOT), in the northern foothills of the Brooks Range, Alaska. Data collected from May to early June 2011 to 2014.
Data file describing the biogeochemistry of samples collected at various sites near Toolik Lake on the North Slope of Alaska. Sample site descriptors include a unique assigned number (sortchem), site, date, time, depth, and category (level of thermokarst disturbance). Physical measures collected in the field include temperature, electrical conductivity, and pH.
In 2010, thaw depth and soil temperature were measured throughout the growing season in control and fertilized plots in the Arctic LTER's moist acidic tundra sites.
Biomass of belowground community groups (bacteria, fungi, protozoa, nematodes, rotifers, tardigrades) determined for organic and mineral soils in moist acidic tundra. Soil carbon and nitrogen content, bulk density, and depth are included.
In arctic tundra near Toolik Lake, Alaska, we incubated a common substrate in a snow addition experiment to test whether snow accumulation around arctic deciduous shrubs altered the environment enough to increase litter decomposition rates. We compared the influence of litter quality on the rate of litter and N loss by decomposing litter from four different plant functional types in a common site. We used aboveground net primary production values and estimated k values from our decomposition experiments to calculate community-weighted mass loss for each site.
Percent moisture, bulk density, percent loss on ignition and percent organic carbon were measured for peat collected from soils in the Imnavait Creek watershed.
In arctic tundra, near Toolik Lake, Alaska, we quantified net N-mineralization rates under ambient and manipulated snow treatments at three different plant communities that varied in abundance and height of deciduous shrubs.
These data are from two remote field campaigns in the Noatak National Preserve. Various thermokarst features and their receiving streams were sampled and characterized. A suite of water chemistry (nutrients, major anions and cations, total suspended sediment) and benthic variables (particulate carbon, nitrogen and phosphorus, and chlorophyll-a) were measured at 6 major sites (2 in 2010 and 4 in 2011). There were additional sites sampled for water chemistry above and below thermokarst features in 2011.
File contains temperature and discharge data for Lake NE 14 Outlet during the 2011 summer field season.
Water samples were taken at 5 locations at both I-Minus2 and Toolik River thermokarst sites (10 sampling locations total). A combination of ISCO and manual grab samples were taken depending on the sampling location and year.
Data were collected to investigate if formation of gully thermokarst (TK) results in lowering of the water table and more rapid evacuation of water from above the frost table. Data were collected from 24 shallow screened wells. 2 replicate rows of 4 wells were located at: (a) a hillslope (HS) ~120m away from the gully TK, (b) perpendicular to the gully TK (TK) and (c) perpendicular to an unimpacted water track (WT) upstream of the gully TK. Note that water levels are the distance below the ground surface and may have organic/peat layers of different thicknesses.
File contains temperature and discharge data for Lake NE 14 Outlet during the 2010 summer field season.
File contains temperature and discharge data for lake NE 14 Outlet during the 2009 summer field season.
This file contains data collected from thermokarst impacted soils, lakes, and streams near Toolik Lake Alaska. Data are also presented for experimental manipulations of water (e.g., time course experiments). Sample descriptors include a unique sortchem #, site, date, time, depth, distance, elevation, treatment, date-time, category, and water type (e.g., lake, surface, soil). Physical/chemical measures collected in the field include temperature, conductivity, and pH.
GroMeteorological parameters were measured hourly adjacent to thermokarst features in the region around Toolik Field Station. Pressure, rainfall, wind speed and direction, solar radiation, air temperature and relative humidity were all measured at 1-3m above the ground surface with an Onset U30 weather station connected to all sensors.
Ground temperatures were measured hourly at ~20-50cm intervals below the ground surface inside and adjacent to thermokarst features in the region around Toolik Field Station. Ground temperatures were measured using Hobo thermistors. Temperatures at 0 and 20cm depths were measured directly in the ground whereas 40cm and deeper measurements were logged from dry wells installed in summer 2009. NE14_TS02dot02_temp is located in the old NE14 thermokarst, upslope.
Ground temperatures were measured hourly at ~20-50cm intervals below the ground surface inside and adjacent to thermokarst features in the region around Toolik Field Station. Ground temperatures were measured using Hobo thermistors. Temperatures at 0 and 20cm depths were measured directly in the ground whereas 40cm and deeper measurements were logged from dry wells installed in summer 2009. TRTK_GT01dot05_temp is located outside the TRTK thermokarst, midslope.
Ground temperatures were measured hourly at ~20-50cm intervals below the ground surface inside and adjacent to thermokarst features in the region around Toolik Field Station. Ground temperatures were measured using Hobo thermistors. Temperatures at 0 and 20cm depths were measured directly in the ground whereas 40cm and deeper measurements were logged from dry wells installed in summer 2009. IM2_GT01dot06_temp is located inside of the I-Minus-2 Gulley thermokarst, downslope.
Hourly air temperature, humidity, wind speed, soil temperature and soil water data from the control area of the ITEX tussock tundra snowfence study site
Hourly data from the Toolik Moist Non-acidic Tussock Experimental plots (MNT). In 1999 a Campbell CR10x data logger was installed in block 2 of the experimental plots. The plots are located on a hillside near Toolik Lake (68 38' N, 149 36'W). Sensors were placed in control and greenhouse sites. Soil temperature profiles are reported in another file (1999-present_MNTsoil).
Soil temperature from three locations on the eastern side of the Toolik River where by snow fences were established as part of IPY. This is a study of how soil temperatures at 10 cm and soil moisture change across the summer at our IPY snow fence site .
The Changing Seasonality of Arctic Stream Systems (CSASN) was active from 2010 to 2012. The CSASN goal was to quantify the relative influences of through flow, lateral inputs, and hyporheic regeneration on the seasonal fluxes C, N, and P in an arctic river network, and to determine how these influences might shift under seasonal conditions that are likely to be substantially different in the future. During the project, well and mini-piezometer samples were collected from various depths near stream channels and analyzed for a variety of nutrients.
The Changing Seasonality of Arctic Stream Systems (CSASN) was active from 2010 to 2012. The CSASN goal was to quantify the relative influences of through flow, lateral inputs, and hyporheic regeneration on the seasonal fluxes C, N, and P in an arctic river network, and to determine how these influences might shift under seasonal conditions that are likely to be substantially different in the future. During the project, background samples were collected from four stream channels and analyzed for a variety of nutrients.
The Changing Seasonality of Arctic Stream Systems (CSASN) was active from 2010 to 2012. The CSASN goal was to quantify the relative influences of through flow, lateral inputs, and hyporheic regeneration on the seasonal fluxes C, N, and P in an arctic river network, and to determine how these influences might shift under seasonal conditions that are likely to be substantially different in the future. Whole Stream Metabolism was calculated using dissolved oxygen, discharge, stage, and temperature measured by sounds deployed in the field.
The (ARCSSTK) did extensive research during 2009-2011 field seasons in Arctic Alaska. Specifically, the ARCSSTK goal Streams goal was to quantify the relative influences of thermokarst inputs on the biogeochemical structure and function of receiving streams. Whole Stream Metabolism was calculated using dissolved oxygen, discharge, stage, and temperature measured by sondes deployed in the field.
A spectrophotometer was used to scan the canopy vegetation at four sites near Imnavait Creek each year from 2008 - 2010 by Toolik Lake LTER, Alaska. Reflectance spectra from 310-1130 nm are presented here with information relating the date and site of the scan.
A spectrophotometer was used to scan the canopy vegetation at four sites along Imnavait Creek in the Kuparuk Watershed near Toolik Lake LTER, Alaska. The resulting reflectance spectra were used to calculate average vegetation indices for each site and collection day.
Vegetation indices calculated from reflectance spectra collected at Arctic LTER experimental plots at Toolik Lake, Alaska during the 2007-2019 growing seasons.
Late season thaw depth was measured in the Arctic Long Term Ecological Research (ARC LTER) experimental plots (1981 Moist Acidic Tussock, 1989 Moist Acidic Tussock, 2006 Low Fertilization Moist Acidic Tussock, 1989 Moist Non-acidic Tussock, 1989 Moist Non-acidic Non-tussock and 1989 Wet Sedge tundra) at Toolik Lake, Alaska using a steel thaw probe. Note: for 2017-2018 only 1989 Moist Non-Acidic Tussock Tundra and 2006 Low fertilization Moist Acidic Tussock Tundra were measured. For other sites it has become difficult to distinguish rocks from frozen soil with a steel thaw probe.
Plant available NH4, NO3, and PO4 was determined at sites near ARC LTER Toolik acidic tundra and at a toposequence along the floodplain of the Sagavanirktuk River using 2 N KCL and weak HCL extracts. This file complies data collected at different times from 1987 through 2001 and includes initial extracts taken for buried bag method of net nitrogen mineralization.
A spectrophotometer was used to scan the canopy vegetation of ITEX harvest plots. The resulting reflectance spectra were used to calculate several vegetation indices of interest (NDVI, EVI, EVI2, PRI, WBI, Chlorophyll Index). Average values of these vegetation indices for each ITEX harvest plot are presented here. These plots also had biomass harvests performed and were analyzed for leaf area and nitrogen content (see 2003-2009gsharvest.csv, 2003-2009gsharvestLAI-N.csv).
Burned and unburned moist acidic tundra sites used to estimate C and N loss from the Anaktuvuk River Fire (2007). These sites were sampled in summer of 2008. Unburned sites were used to develop a method for estimating soil organic layer depth and plant biomass, and for determining the characteristics of unburned soil organic layers. In burned sites, we characterized residual organic soils and used biometric measurements of tussocks to reconstruct pre-fire soil organic layer depth.
To determine temporal and spatial patterns in arctic stream biogeochemistry we conducted three synoptic surveys of streams throughout a 48km2 watershed near Toolik Lake, AK in spring (early-June), summer (mid-July), and fall (mid-September) 2011. During each synoptic survey, we sampled 52 sites within a period of four days to minimize the effect of temporal hydrologic variability. At each site we measured stream temperature, pH, and conductivity and sampled water for solute analysis.
Soil temperature, moisture content and thaw depth of the ITEX flux survey plots. Survey plots were located in the Toolik Lake LTER fertilization experiment in Alaska; at Imnavait Creek, Alaska; at Paddus, Latnjajaure and the Stepps site near Abisko in northern Sweden; at various sites in Adventdalen, Svalbard; in the Zackenberg valley, Northeast Greenland; at BEO near Barrow, Alaska and at the Anaktuvuk River Burn in Alaska. Measurements were made during the growing seasons 2003 to 2009.
The Anaktuvuk River Fire occurred in 2007 on the North Slope of Alaska. In 2008, three eddy covariance towers were established at sites represent ing unburned tundra, moderately burned tundra, and severely burned tundra. Several times during the 2008-2014 growing seasons, thaw depth was measured at approximately 70 points near each of these towers . Data presented here are the individual measurements for each site and date.
Summary of three methods used to estimate the Leaf Area Index (LAI) of 19 1m x 1m plots sampled with a point frame near the LTER Shrub plots at the Toolik Field Station in AK the summer of 2012. The methods used were: (1) exponential relationship between LAI and NDVI as measured above the canopy with a Unispec spetroradiometer; (2) Delta-T SunScan canopy analyzer held at 5 cm above the ground under both direct and diffuse light conditions; (3) pin-drop point frame tequnique. Where values have been averaged (such as for the NDVI and SunScan measurements), the standard deviation is given.
Soil temperature at 5cm and 10cm depth [°C], volumetric water content (VWC) [%] and depth of thaw [cm] for 14 shrub canopy flux plots measured in vicinity of the Toolik Field Station, AK in 2012.
This file contains limited daily summaries of PAR, relative humidity, and temperature data monitored above, within, and below Betula nana and Salix pulchra shrub canopies at two locations near Toolik Lake, Alaska during the summer of 2012. The location of the PAR sensor and dataloggers were co-located with the LTER shrub plots (block 1 and 2), also used for the chamber flux and point frame measurements taken this same year.
This file contains irradiance (PAR) and diffuse light data logged from a beam fraction (BF3) sensor near Toolik Lake, Alaska during the summer of 2012. The data comes from a compilation of automated datalogger readings as well as measurements taken during the field season in conjunction with the Delta-T SunScan wand to measure PAR in tall shrub canopies dominated by Betula nana or Salix pulchra species. The sensor was leveled and mounted to a 2m tripod in each location, and programmed to record instantaneous readings in 30 second to 5 minute intervals.
Within-canopy PAR was measured with a Delta-T SunScan wand every 15 cm from the ground to above the canopy under both direct and diffuse light. The data includes all outputs from the SunScan wand: time of measurement, spread of PAR sensors, total irradiance, total diffuse light, and individual outputs of 64-PAR sensors on the SunScan wand. These measurements were taken for 1m x 1m chamber flux (n=14) and point frame (n=19) plots as well as sites four montitored remotely by PAR sensors located above, within, and below shrub canopies.
Peat cores were collected along the Dalton Highway in 1989 and analysed for percent moisture, percent organic carbon, bulk densitey, del C-13, and radiocarbon content at varying depth intevals throughout the core. Samples were collected to the mineral zone and kept in cold storage until analysis. Samples were collected from 12 sites.
This file contains PAR , relative humidity, and temperature data logged every five minutes from within, below, and above Betula nana and Salix pulchra shrub canopies at two locations near Toolik Lake, Alaska during the summer of 2012. The location of the PAR sensor and dataloggers were co-located with the LTER shrub plots (block 1 and 2), also used for the chamber flux and point frame measurements taken this same year.
Soil moisture and temperature were recorded at the Anaktuvuk River burn area during the summers from 2010 to 2013. Six sensors were deployed and measured temperature on half-hourly intervals over the summer and into the fall depending on battery function. Sensors were place in a hexagonal shape around a central datalogger. Note that over time sensor depths changed due to frost heave and other environmental factors. All data contained should be treated as suspect where sensors may have been at surface. These sensors were removed August 20, 2013, no replacement sensors were installed.
Soil moisture and temperature were recorded at the Anaktuvuk River burn area during the summers from 2010 to 2013. Six sensors were deployed and measured temperature on half-hourly intervals over the summer and into the fall depending on battery function. Sensors were place in a hexagonal shape around a central datalogger. Note that over time sensor depths changed due to frost heave and other environmental factors. All data contained should be treated as suspect where sensors may have been at surface. These sensors were removed August 23, 2013, no replacement sensors were installed.
Soil moisture and temperature were recorded at the Anaktuvuk River burn area during the summers from 2010 to 2013. Six sensors were deployed and measured temperature on half-hourly intervals over the summer and into the fall depending on battery function. Sensors were place in a hexagonal shape around a central data logger. Note that over time sensor depths changed due to frost heave and other environmental factors. All data contained should be treated as suspect where sensors may have been at surface. These sensors were removed August 20, 2013, no replacement sensors were installed.
Decadal file describing the physical lake parameters recorded at various lakes near Toolik Research Station during summers from 1975 to 1989. Depth profiles at the sites of physical measures were collected in situ. Values measured included temperature, conductivity, pH, dissolved oxygen, Chlorophyll A, Secchi disk depth and PAR. Note that some sample depths also have additional parameters measured and available in separate files for water chemistry and primary production.
Average conductivity of the epilimnion (0-3m of water depth) found in Toolik Lake during the month of July.