Global Change Master Directory gsfc-gcmduso@mail.nasa.gov 50 2013-05-20T01:20:36Z http://mddemo.gsfc.nasa.gov/KeywordSearch/OpenSearch.do 25 0 http://gcmd.gsfc.nasa.gov/getdif.htm?[GCMD]gov.noaa.ngdc.G10107 -180.0,-90.0,180.0,90.0 2006-01-01T00:00:00Z T00:00:00Z 2011-07-21T04:00:00Z

Visible and infrared imagery from DMSP Operational Linescan System (OLS) instruments are used to monitor the global distribution of clouds and cloud top temperatures twice each day. The archive data ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G01257 -180.0,-90.0,180.0,90.0 1957-01-01T00:00:00Z 1990-01-01T00:00:00Z 2011-04-19T04:00:00Z

ABSTRACT: The ionosphere is that part of the Earth's atmosphere that results mainly from the photo ionization of the upper atmosphere. Traditionally, the following ionospheric regions and their approximate ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G01119 -180.0,-90.0,180.0,90.0 1975-04-01T00:00:00Z T00:00:00Z 2011-03-10T05:00:00Z

ABSTRACT: Visible and infrared imagery from DMSP Operational Linescan System (OLS) instruments are used to monitor the global distribution of clouds and cloud top temperatures twice each day. The ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G00603 -180.0,-90.0,180.0,90.0 1972-01-01T00:00:00Z T00:00:00Z 2011-03-07T05:00:00Z

ABSTRACT: Airglow is a faint luminescence of the earth's upper atmosphere. The emitted electromagnetic radiation results mainly from photo-chemical reactions of upper atmospheric constituents. Although ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G00590 -180.0,-90.0,180.0,90.0 1938-01-01T00:00:00Z T00:00:00Z 2011-03-07T05:00:00Z

ABSTRACT: The National Geophysical Data Center receives the K indices on a current basis from approximately 85 observatories. The K index is a quasi-logarithmic local index of the 3-hourly range in ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G00581 -180.0,-90.0,180.0,90.0 1958-01-01T00:00:00Z T00:00:00Z 2011-03-07T05:00:00Z

ABSTRACT: Sudden ionospheric disturbances (SID) are caused by solar flare enhanced X-rays in the 1 to 10 angstrom range. Solar flares can produce large increases of ionization in the D-region of the ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G00583 -180.0,-90.0,180.0,90.0 1957-01-01T00:00:00Z T00:00:00Z 2011-03-07T05:00:00Z

ABSTRACT: The National Geophysical Data Center receives magnetograms from over 200 geomagnetic observatories. The Center archives data from 1867 to the present, however the primary holdings are from ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G00563 -180.0,-90.0,180.0,90.0 1957-01-15T00:00:00Z 1975-01-01T00:00:00Z 2011-03-03T05:00:00Z

ABSTRACT: The oblique incidence sweep-frequency ionospheric sounding technique uses the same principle of operation as the vertical incidence sounder. The primary difference is that the transmitter ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G00551 -180.0,-90.0,180.0,90.0 1944-03-01T00:00:00Z T00:00:00Z 2011-03-03T05:00:00Z

ABSTRACT: The standard (analog) ionosonde produces photographic records known as ionograms, which show the variations of the virtual height of reflection as a function of the radio frequency. The ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G00533 -180.0,-90.0,180.0,90.0 1931-01-01T00:00:00Z T00:00:00Z 2011-03-03T05:00:00Z

ABSTRACT: The solar magnetic field is approximately a dipole at high latitudes and is highly irregular at middle and low latitudes. The field apparently gives rise to a coupling between solar differential ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G00594 -180.0,-90.0,180.0,90.0 1957-01-01T00:00:00Z 1984-11-20T00:00:00Z 2011-03-02T05:00:00Z

ABSTRACT: An aurora involves emitted electromagnetic radiation that results primarily from the interaction of energetic, extra-atmospheric particles with the neutral gases of the upper atmosphere. ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G00546 -180.0,-90.0,180.0,90.0 1966-07-01T00:00:00Z 1979-08-01T00:00:00Z 2011-03-02T05:00:00Z

ABSTRACT: The National Geophysical Data Center holds a published series of observations of Jovian Dekametric Emission bursts recorded on the University of Colorado's Boulder radio spectrograph. Between ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G00582 -180.0,-90.0,180.0,90.0 1967-01-01T00:00:00Z T00:00:00Z 2011-03-02T05:00:00Z

ABSTRACT: Satellites monitor in situ the effect of the Sun on the near-Earth environment. The GOES and SOLRAD satellites orbited at geostationary levels, about 22,000 miles above the Earth's surface. ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G00538 -180.0,-90.0,180.0,90.0 1939-01-01T00:00:00Z T00:00:00Z 2011-03-02T05:00:00Z

ABSTRACT: The solar corona is the outermost layer of the sun's atmosphere--a very hot halo (millions of degrees), that, in the form of the solar wind, extends well past the Earth's orbit. The corona ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G00547 -180.0,-90.0,180.0,90.0 1978-08-01T00:00:00Z T00:00:00Z 2011-03-02T05:00:00Z

ABSTRACT: The "solar constant" is, in fact, not constant. Recent satellite observations have found that the Total Solar Irradiance (TSI), the amount of solar radiation received at the top of the Earth's ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G00534 -180.0,-90.0,180.0,90.0 1919-03-01T00:00:00Z T00:00:00Z 2011-03-02T05:00:00Z

ABSTRACT: Solar Prominences and Filaments appear as dark filamentary objects on the solar disk (filaments) and as protuberances on the edge of the solar disk (prominences). They generally sit above ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G00542 -180.0,-90.0,180.0,90.0 1978-11-01T00:00:00Z T00:00:00Z 2011-03-02T05:00:00Z

ABSTRACT: The ultraviolet (UV) part of the electromagnetic spectrum ranges between 5 and 400 nanometers (nm). As the SORCE (Solar Radiation and Climate Experiment satellite) mission states, far UV ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G00532 -180.0,-90.0,180.0,90.0 1700-01-01T00:00:00Z T00:00:00Z 2011-03-02T05:00:00Z

ABSTRACT: In 1848 the Swiss astronomer Johann Rudolph Wolf introduced a daily measurement of sunspot number. His method, which is still used today, counts the total number of spots visible on the ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G00145 -180.0,-90.0,180.0,90.0 1965-11-15T00:00:00Z 1977-12-15T00:00:00Z 2011-03-01T05:00:00Z

ABSTRACT: For radio waves transmitted through the ionosphere with frequencies much larger (50 to 1300MHz) than the plasma frequency (up to 15MHz), very small-scale fluctuations of electron density ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G00188 -180.0,-90.0,180.0,90.0 1978-11-01T00:00:00Z T00:00:00Z 2011-03-01T05:00:00Z

ABSTRACT: The TIROS/NOAA satellite series, also known as POES, is designed to meet the National Oceanic and Atmospheric Administration's need for operational, remote sensing products for numerical ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G00216 -180.0,-90.0,180.0,90.0 1947-02-14T00:00:00Z T00:00:00Z 2011-03-01T05:00:00Z

ABSTRACT: Scientists monitor the structure of the solar corona, the outer most regions of the Sun's atmosphere, using radio waves. The surface of the Sun is 6,000 degrees Kelvin, while the high corona ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G00037 -180.0,-90.0,180.0,90.0 1974-07-01T00:00:00Z T00:00:00Z 2011-02-28T05:00:00Z

ABSTRACT: Solid state detectors with pulse height discrimination measure proton, alpha-particle, and electron fluxes. E1 and I1 channels are responding primarily to trapped outer-zone particles. The ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G00038 -180.0,-90.0,180.0,90.0 1974-07-01T00:00:00Z T00:00:00Z 2011-02-28T05:00:00Z

ABSTRACT: Three orthogonal flux-gate magnetometer elements, (spinning twin fluxgate magnetometer prior to GOES-8) provide magnetic field measurements in three mutually perpendicular components: HP, ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.G00036 -180.0,-90.0,180.0,90.0 1974-07-01T00:00:00Z T00:00:00Z 2011-02-28T05:00:00Z

ABSTRACT: Ion chamber detectors provide whole-sun X-ray fluxes for the 0.5-to-3 (0.5-to-4 prior to GOES-8) and 1-to-8 Angstrom wavelength bands. The X-ray sensors may experience significant bremsstrahlung ...

http://gcmd.gsfc.nasa.gov/getdif.htm?[NOAA-NMMR]gov.noaa.ngdc.solar.G00039 -180.0,-90.0,180.0,90.0 1977-01-01T00:00:00Z T00:00:00Z 2011-02-28T05:00:00Z

ABSTRACT: This data file consists of solar brightness and magnetic discontinuities collected by the Solar Observing Optical Network (SOON). SOON consists of up to five US Air Force Air Weather Service ...