GCMD new keyword request

jkstarnes · by **jkstarnes** » Wed Nov 13, 2024 2:35 pm America/New_York

Hi! I have a rather extensive request for new GCMD keywords. These requests are being made on behalf of the data producers for https://nsidc.org/data/modscgdrf_nrt/versions/1. The forthcoming Version 2 of this data set includes an upgrade to netCDF format. The requested keywords will be parameters embedded within the netCDF files, and will also be used in the accompanying NSIDC metadata. The data producers have done a thorough review of existing GCMD keywords to ensure that requesting new keywords is necessary. Please let me know if you have any questions or concerns about this request.

Thank you,

Jesslyn

SNOW FRACTION
EARTH SCIENCE > CRYOSPHERE > SNOW/ICE > SNOW FRACTION
Definition: The areal extent of snow-covered ground, expressed as the mathematical fraction of a region covered with snow.
Source: Painter, T.H., Rittger, K., McKenzie, C., Slaughter, P., Davis, R.E., & Dozier, J. (2009). Retrieval of subpixel snow-covered area, grain size, and albedo from MODIS. Remote Sensing of Environment, 113, 868-879, doi: 10.1016/j.rse.2009.01.001.

LAND ICE FRACTION
EARTH SCIENCE > CRYOSPHERE > SNOW/ICE > LAND ICE FRACTION
Definition: The areal extent of ice, typically glacier ice, expressed as the mathematical fraction of a region covered with ice.
Source: Painter, T.H., Rittger, K., McKenzie, C., Slaughter, P., Davis, R.E., & Dozier, J. (2009). Retrieval of subpixel snow-covered area, grain size, and albedo from MODIS. Remote Sensing of Environment, 113, 868-879, doi: 10.1016/j.rse.2009.01.001.

SNOW GRAIN SIZE
EARTH SCIENCE > CRYOSPHERE > SNOW/ICE > SNOW GRAIN SIZE
Definition: The size of individual snow grains in micrometers.
Source 1: Painter, T.H., Rittger, K., McKenzie, C., Slaughter, P., Davis, R.E., & Dozier, J. (2009). Retrieval of subpixel snow-covered area, grain size, and albedo from MODIS. Remote Sensing of Environment, 113, 868-879, doi: 10.1016/j.rse.2009.01.001.
Definition 2: Painter, T.H., Bryant, A.C., & Skiles, S.M. (2012). Radiative forcing by light absorbing impurities in snow from MODIS surface reflectance data. Geophysical Research Letters, 39, L17502, doi: 10.1029/2012gl052457.

VEGETATION FRACTION
EARTH SCIENCE > BIOSPHERE > VEGETATION > VEGETATION FRACTION
Definition: The areal extent of vegetation-covered ground, expressed as the mathematical fraction of a region covered with vegetation.
Source: Painter, T.H., Rittger, K., McKenzie, C., Slaughter, P., Davis, R.E., & Dozier, J. (2009). Retrieval of subpixel snow-covered area, grain size, and albedo from MODIS. Remote Sensing of Environment, 113, 868-879, doi: 10.1016/j.rse.2009.01.001.

ROCK FRACTION
EARTH SCIENCE > LAND SURFACE > LAND USE/LAND COVER > ROCK FRACTION
Definition: The areal extent of rock or soil-covered ground, expressed as the mathematical fraction of a region covered with rock or soil.
Source: Painter, T.H., Rittger, K., McKenzie, C., Slaughter, P., Davis, R.E., & Dozier, J. (2009). Retrieval of subpixel snow-covered area, grain size, and albedo from MODIS. Remote Sensing of Environment, 113, 868-879, doi: 10.1016/j.rse.2009.01.001.

SHADE FRACTION
EARTH SCIENCE > LAND SURFACE > LAND USE/LAND COVER > SHADE FRACTION
Definition: Spectral fraction of photometric shade.
Source: Painter, T.H., Rittger, K., McKenzie, C., Slaughter, P., Davis, R.E., & Dozier, J. (2009). Retrieval of subpixel snow-covered area, grain size, and albedo from MODIS. Remote Sensing of Environment, 113, 868-879, doi: 10.1016/j.rse.2009.01.001.

SNOW RADIATIVE FORCING
EARTH SCIENCE > CRYOSPHERE > SNOW/ICE > SNOW RADIATIVE FORCING
Definition: Snow radiative forcing is a measure of the additional absorption of solar radiation from light-absorbing particles (LAP) such as dust or soot. Units of measure are watts per square meter (W/m2). Radiative forcing is calculated by the difference between the net (downward minus upward) radiative fluxes (irradiance) with and without LAP across a portion of the visible spectrum, for example from 0.350 to 0.876 um. This value depends on the amount of dust or soot, particle size distribution, and the amount of incoming solar radiation.
Source: Painter, T.H., Bryant, A.C., & Skiles, S.M. (2012). Radiative forcing by light absorbing impurities in snow from MODIS surface reflectance data. Geophysical Research Letters, 39, L17502, doi: 10.1029/2012gl052457.

VISIBLE SNOW DARKENING
EARTH SCIENCE > CRYOSPHERE > SNOW/ICE > VISIBLE SNOW DARKENING
Definition: Snow darkening is a measure of the potential additional absorption of solar radiation from light-absorbing particles (LAP) such as dust or soot. Units of measure are a fraction or a percent of the visible broadband spectrum, for example from 0.350 to 0.876 um. This value depends on the amount of dust or soot and particle size distribution.
Source: Painter, T.H., Bryant, A.C., & Skiles, S.M. (2012). Radiative forcing by light absorbing impurities in snow from MODIS surface reflectance data. Geophysical Research Letters, 39, L17502, doi: 10.1029/2012gl052457.

by **GCMD - tstevens** » Thu Nov 14, 2024 8:12 am America/New_York

Jesslyn,

Thank you for your keyword request. We will review it and let you know when it is complete.

by **GCMD - tstevens** » Wed Nov 20, 2024 10:58 am America/New_York

@jkstarnes
After reviewing the keywords, I have a few follow-up questions.

1. Snow Grains is also under Precipitation. Does a keyword need to be added under that hierarchy as well? See https://gcmd.earthdata.nasa.gov/KeywordViewer/scheme/Earth%20Science/6a16461a-49b9-4887-802f-2320c6dc4dd2?gtm_keyword=SNOW%20GRAINS&gtm_scheme=Earth%20Science.

2. Should you consider adding ‘ROCK FRACTION’ under the Solid Earth keywords? We have an extensive hierarchy there; see https://gcmd.earthdata.nasa.gov/KeywordViewer/scheme/Earth%20Science/ba8d7f68-ad3a-4874-bc75-312b24b1b1ac/?gtm_keyword=ROCKS/MINERALS/CRYSTALS.

jkstarnes · by **jkstarnes** » Wed Nov 20, 2024 11:50 am America/New_York

Hi! See answers to your questions below. -Jesslyn

1. For our purposes, we don't need an additional Snow Grain Size keyword under Precipitation, as this data set is focused on already deposited snow, rather than fresh precipitation. But I imagine other folks might find it useful?

2. This data set relies on a satellite-based remote sensing of surface features, which is why we requested the Rock Fraction keyword under LAND SURFACE > LAND USE/LAND COVER >. Here we use rock fraction to describe land cover that consists of exposed rock or soil-covered ground (as opposed to land cover of vegetation or snow). We feel this hierarchy makes the most sense for this data set.

by **GCMD - tstevens** » Wed Nov 20, 2024 3:48 pm America/New_York

jkstarnes · by **jkstarnes** » Wed Nov 20, 2024 4:45 pm America/New_York

These look great! Thank you so much. -Jesslyn

by **GCMD - tstevens** » Thu Nov 21, 2024 7:16 am America/New_York

Thank You. The keywords will be published next Friday November 29 as part of our next keyword release.

jkstarnes · by **jkstarnes** » Thu Nov 21, 2024 10:43 am America/New_York

Great, thank you so much!

Forum

GCMD new keyword request

GCMD new keyword request

Re: GCMD new keyword request

Re: GCMD new keyword request

Re: GCMD new keyword request

Re: GCMD new keyword request

Re: GCMD new keyword request

Re: GCMD new keyword request

Re: GCMD new keyword request