MODIS__Arctic__MeltPondFraction__UHAM-CliSAP-ICDC__v01__12.5km__8day (ds)

hdl:21.14106/b2141d13a90a032853670ceebc646132cbae5c65

Rösel, Anja; Kaleschke, Lars; Kern, Stefan

Dataset
Summary
Reflectances measured in the visible frequency range at three channels of the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Earth Observation Satellite (EOS) TERRA were used to derive the melt pond fraction on Arctic sea ice using an artificial neural network. This analysis was done on reflectances gridded onto a polar-stereographic grid tangent to the Earths' surface at 70 deg N with 500 m grid resolution. The reflectances used originate from the 8-day composite reflectances provided via https://wist.echo.nasa.gov/api/ as product: "MODIS surface Reflectance 8-Day L3 Global 500m SIN Grid V005". After gridding and flagging for clouds and other disturbances the artificial neural network was applied, providing fractions of three surface classes: 1) melt ponds, 2) sea ice and snow, and 3) open water at 500 m grid resolution. This data has been interpolated onto a similar polar-stereographic grid but with 12.5 km grid resolution.
The data set offered here comprises several data layers: the melt pond fraction, its standard deviation, the open water fraction, and the number of individual valid grid cells with 500 m grid resolution included in each 12.5 km grid cell. In addition, in three separate data layers melt pond fraction, its standard deviation, and the open water fraction are given with those grid cells (with 12.5 km grid resolution) flagged as invalid where less than 90 % of the native 500 m grid resolution data indicate clear sky conditions. Valid for all these layers is, that grid cells with an open water fraction larger than 85 % have been flagged as invalid as well.
Project
CliSAP (Integrated Climate System Analysis and Prediction)
Location(s)
Arctic Ocean
Additional Information
roeseletal_MeltPondsonArcticSeaIceDeterminedfromMODISSatelliteDatausinganArtificialNeuralNetwork_TC_6_2012.pdf
Spatial Coverage
Longitude 0 to 360 Latitude 60 to 90 Altitude: 0 m
Temporal Coverage
2000-05-08 to 2011-09-13 (calendrical)
Use constraints
For scientific use only
Data Catalog
World Data Center for Climate
Access constraints
registered users
Size
2.32 GiB (2486353920 Byte)
Format
netCDF.tar
Status
completely archived
Creation Date
Download Permission
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Cite as
[ Derived from parent entry - See data hierarchy tab ]
Rösel, Anja; Kaleschke, Lars; Kern, Stefan (2013). Gridded Melt Pond Cover Fraction on Arctic Sea Ice derived from TERRA-MODIS 8-day composite Reflectance Data. World Data Center for Climate (WDCC) at DKRZ. https://doi.org/10.1594/WDCC/MODIS__Arctic__MPF

BibTeX RIS
Description
Accuracy and reliability of the offered data have been tested against a number of independent data comprising ship-based observations, air-borne observations, and satellite observations; results of these activities are published as Roesel, A., L. Kaleschke, and G. Birnbaum, 2012. Melt ponds on Arctic sea ice determined from MODIS satellite data using an artifical neural network. The Cryosphere, 6, 431-446, doi: 10.5194/tc-6-431-2012.
Description
There is no specific report about the horizontal accuracy of this data set available.

Temporal completeness:
The data set covers the entire EOS-TERRA MODIS time series from 2000-2011. The data is however limited to the melting period which is defined, for our data set as beginning at May 9 (May 8 in leap years) and ending at September 13 (September 12 in leap years). Data are missing for 8-day composites starting at June 18 and June 26 2001.

Spatial completeness:
Several factors, as are detailed below, limit the spatial coverage:
i) Limited day light and gaps in acquisition of the original MODIS data causes a data gap centered at the pole which has a varying latitudinal extent.
ii) Varying cloud cover and sea ice extent causes data gaps to occur allover the region.
iii) In order to focus on the Arctic Ocean regions south of 60°N are excluded.
Description
Accuracy and reliability of the offered data have been tested against a number of independent data comprising ship-based observations, air-borne observations, and satellite observations; results of these activities are published as Roesel, A., L. Kaleschke, and G. Birnbaum, 2012. Melt ponds on Arctic sea ice determined from MODIS satellite data using an artifical neural network. The Cryosphere, 6, 431-446, doi: 10.5194/tc-6-431-2012.
Description
There is no specific report about the horizontal accuracy of this data set available.
The data set is offered at a certain spatial resolution which should be regarded as a compromise between a reasonable spatial coverage with valid data and an as high as possible degree of resolving small-scale variations. The temporal resolution to 8-day composites poses limits to the spatial resolution and thus horizontal accuracy anyways.
Users should be aware of the fact that usage of an 8-day composite of clear-sky radiances could mean that the information retrieved for adjacent grid cells may originate, in extreme cases, from data of two different days which are 7 days apart.
Users interested in products at native spatial resolution (500 m) or finer temporal resolution (daily) should contact the author and/or the investigator (see above).
VariableUnit
land_binary_maskCF
n/a
latitudeCF
n/a
longitudeCF
n/a
melt_pond_area_fraction_at_top_of_sea_ice
n/a
melt_pond_area_fraction_at_top_of_sea_ice (standard_deviation)
n/a
melt_pond_area_fraction_at_top_of_sea_ice_assuming_clear_sky
n/a
melt_pond_area_fraction_at_top_of_sea_ice_assuming_clear_sky (standard_deviation)
n/a
number_of_valid_data_per_grid_cell
n/a
projection_x_coordinateCF
n/a
projection_y_coordinateCF
n/a
sea_area_fractionCF
n/a
sea_area_fraction_assuming_clear_sky
n/a
timeCF
n/a
Contact typePersonORCIDOrganization
Metadata
Dr. Stefan Kern
-
University of Hamburg (IfM)

Parent

MODIS__Arctic__MeltPondFraction__UHAM-CliSAP-ICDC__v01__12.5km__8day
Details

Parent project(s)

Integrated Climate System Analysis and Prediction

[Entry acronym: MODIS__Arctic__MPF_ds] [Entry id: 2444152]