14 results found Displaying all 14 entries
Upper Kuparuk River Region NDVI trend 1985-2007 (Raynolds et al 2010)
![]() |
Alaska Geobotany Center (AGC)
-
Landsat TM and ETM data were used to calculate NDVI for the study area (823 km^2). This image shows the results of a slope of linear regression of NDVI for 1985, 1989, 1995, 1999, 2004, 2007. Only pixels with significant trends (p < 0.05) area shown. The research was funded by NSF grants for studying the Greening of the Arctic and Seasonality: NSF grants OPP-0120736, ARC-0531180, and...
Complete
2019-08-14 15:06:19 -0800
|


Data
Alaska Arctic AVHRR NDVI Map
![]() |
Alaska Geobotany Center (AGC)
-
The normalized difference vegetation index (NDVI) is a measure of greenness. NDVI was calculated as: NDVI = (NIR - R) / (NIR + R), where NIR is the spectral reflectance in the AVHRR near-infrared channel (0.725-1.1 µm, channel 2) where light-reflectance from the plant canopy is dominant, and R is the reflectance in the red channel (0.5 to 0.68 µm, channel 1), the portion of the spectrum where...
Complete
2019-08-26 13:59:23 -0800
|

Data
Circumpolar Arctic AVHRR NDVI Trend 1982-2008 (Bhatt et al. 2010)
![]() |
Alaska Geobotany Center (AGC)
-
The normalized difference vegetation index (NDVI) is a measure of greenness. NDVI was calculated as: NDVI = (NIR - R) / (NIR + R), where NIR is the spectral reflectance in the AVHRR near-infrared channel (0.725-1.1 µm, channel 2) where light-reflectance from the plant canopy is dominant, and R is the reflectance in the red channel (0.5 to 0.68 µm, channel 1), the portion of the spectrum where...
Complete
2019-08-15 13:35:35 -0800
|

Data
Circumpolar Arctic AVHRR False Color-Infrared (CIR) Map
![]() |
Alaska Geobotany Center (AGC)
-
Advanced Very High Resolution Radiometer (AVHRR) data were obtained from the USGS Global AVHRR 10-day composite data. (http://edcdaac.usgs.gov/1KM/1kmhomepage.asp) (Markon et al. 1995). Glaciers and oceans were masked out using information from the Digital Chart of the World (ESRI 1993). The image is composed of 1 x 1-km pixels. The color of each pixel was determined by its reflectance at the...
Complete
2019-08-16 12:49:41 -0800
|

Data
Howe Island Patterned-Ground 10 x 10 m Grids
Alaska Geobotany Center (AGC)
-
The Howe Island biocomplexity grid is located on a 1.5 x 0.5 km island off the delta of the Sagavanirktok River, west of the Endicott Causeway in the Prudhoe Bay oilfield, AK. There is one 10 x 10 m grid, with a complex of vegetation types created by 10 to 30-m polygonal cracking due to permafrost ice-wedges, smaller 1 to 3-m non-sorted circles, and small 10-20 cm surficial desiccation...
Complete
2019-08-16 14:01:36 -0800
|


Data
Happy Valley Patterned-Ground 10 x 10 m Grids
![]() |
Alaska Geobotany Center (AGC)
-
The Happy Valley patterned-ground grids are located in Subzone E, the warmest part of the Arctic, in the foothills of the Brooks Range, just west of the Sagavanirktok River and the Dalton Highway. There are three 10 x 10-m grids along a hill slope, one on the crest of the hill (dry), one on the mid-slope (mesic), and one on the toe slope (wet). All three have tussock-sedge, erect dwarf-shrub,...
Unknown
2019-08-16 13:57:14 -0800
|


Data
Circumpolar Arctic AVHRR NDVI Map
![]() |
The normalized difference vegetation index (NDVI) is a measure of greenness. NDVI was calculated as: NDVI = (NIR - R) / (NIR + R), where NIR is the spectral reflectance in the AVHRR near-infrared channel (0.725-1.1 µm, channel 2) where light-reflectance from the plant canopy is dominant, and R is the reflectance in the red channel (0.5 to 0.68 µm, channel 1), the portion of the spectrum where...
Complete
2019-08-02 13:49:35 -0800
|
Data
Alaska Arctic False Color-Infrared (CIR) Map
![]() |
Alaska Geobotany Center (AGC)
-
Advanced Very High Resolution Radiometer (AVHRR) data were obtained from the USGS Global AVHRR 10-day composite data (http://edcdaac.usgs.gov/1KM/1kmhomepage.asp) (Markon et al. 1995). Glaciers and oceans were masked out using information from the Digital Chart of the World (ESRI 1993). The image is composed of 1 x 1-km pixels. The color of each pixel was determined by its reflectance at the...
Complete
2019-08-19 14:00:33 -0800
|

Data
Sagwon Patterned-Ground 10 x 10 m Grids
![]() |
Alaska Geobotany Center (AGC)
-
The Sagwon patterned-ground grids are located at the northern edge of the rolling foothills, at the boundary with the flatter coastal plain. This is also the boundary between Subzones E and D, and between the acidic tundra to the south and the nonacidic tundra to the north. There are three 10 x 10 m grids, one with acidic tussock-sedge, erect dwarf-shrub, moss vegetation (MAT), and two grids in...
Ongoing
2019-08-16 13:55:37 -0800
|


Data
Deadhorse Patterned-Ground 10 x 10 m Grids
![]() |
Alaska Geobotany Center (AGC)
-
The Deadhorse patterned-ground grid is located near the industrial center of Deadhorse, AK, within 15 km of the Beaufort Sea coast. There is one 10 x 10 m grid, with a complex of vegetation types created by non-sorted circles, with sparser vegetation in the circles and more continuous vegetation between the circles.
Back to: [Patterned-Ground 10 x 10 m...
Complete
2019-08-16 14:00:04 -0800
|


Data
Circumpolar Arctic Biomass (Raynolds et al 2012)
![]() |
Alaska Geobotany Center (AGC)
-
This map portrays an estimate of above ground plant biomass for the tundra biome based on trans-Arctic field data and AVHRR NDVI (Raynolds et al. 2012). Aboveground phytomass was sampled on transects along the Arctic bioclimate gradient in North America (1750 km long, 8 locations sampled 2003–2006) and Eurasia (1500 km, 5 locations sampled 2007–2010). The study locations were chosen to...
Complete
2019-08-15 13:30:05 -0800
|

Data
West Dock Patterned-Ground 10 x 10 m Grids
Alaska Geobotany Center (AGC)
-
The West Dock biocomplexity grid is located near the water pumping facility at West Dock in the Prudhoe Bay oilfield, AK, within 1 km of the Beaufort Sea coast. There is one 10 x 10 m grid with nontussock sedge, prostrate dwarf-shrub, moss tundra on sandy soils.
Back to: [Patterned-Ground 10 x 10 m Grids](/catalog/entries/8516-patterned-ground-10-x-10-m-grids-raynolds-et-a)
Go to...
Complete
2019-08-16 14:00:51 -0800
|


Data
Upper Kuparuk River Region SPOT NDVI
![]() |
Alaska Geobotany Center (AGC)
-
The French SPOT satellite data (20-m resolution) were obtained on 28 July 1989 and provides a view of the mapped region from space. NDVI is an index of vegetation greenness that can be linked to plant biomass and other biophysical properties of the vegetation, such as CO2 and photosynthesis. The NDVI = (NIR - R)/(NIR + R), where NIR and R are the spectral reflectance values of the near-infrared...
Complete
2019-08-19 14:14:04 -0800
|

Data
Franklin Bluffs Patterned-Ground 10 x 10 m Grids
Alaska Geobotany Center (AGC)
-
The Franklin Bluffs patterned-ground grids are located in Subzone D, on the coastal plain of the Alaska North Slope, just west of the Sagavanirktok River. There are three 10 x 10 m grids: one near the rim of an abandoned river terrace (dry), one on the same terrace, but further back from the edge and a little lower in elevation (mesic), and one on the lower abandoned river terrace below the...
Ongoing
2019-08-20 14:00:50 -0800
|


Data