Editing Sea surface temperature (section)

===Weather satellites===
{{See also|Weather satellite|Satellite temperature measurement}}
[[File:MODIS sst.png|thumb|2003–2011 SST based on [[Moderate-Resolution Imaging Spectroradiometer|MODIS]] Aqua data]]
Weather satellites have been available to determine sea surface temperature information since 1967, with the first global composites created during 1970.<ref>{{cite journal|url=http://docs.lib.noaa.gov/rescue/mwr/100/mwr-100-01-0010.pdf|title=Global Sea-Surface Temperature Distribution Determined From an Environmental Satellite|author=P. Krishna Rao, W. L. Smith, and R. Koffler|pages=10–14|journal=[[Monthly Weather Review]]|volume=100|date=January 1972|access-date=2011-01-09|issue=1|doi=10.1175/1520-0493(1972)100<0010:GSTDDF>2.3.CO;2|bibcode = 1972MWRv..100...10K}}</ref> Since 1982,<ref>{{cite book|url=https://books.google.com/books?id=qzYrAAAAYAAJ&pg=PA2|page=2|author=National Research Council (U.S.). NII 2000 Steering Committee|title=The unpredictable certainty: information infrastructure through 2000; white papers|publisher=National Academies|year=1997|isbn=9780309060363}}</ref> [[satellite]]s have been increasingly utilized to measure SST and have allowed its [[Spatial variability|spatial]] and [[time|temporal]] variation to be viewed more fully. [[Satellite temperature measurement|Satellite measurements of SST]] are in reasonable agreement with [[in situ]] temperature measurements.<ref>{{cite journal|journal=[[Journal of Geophysical Research]]|date=2001-02-15|volume=106|author1=W. J. Emery|author2=D. J. Baldwin|author3=Peter Schlüssel|author4=R. W. Reynolds|name-list-style=amp|title=Accuracy of in situ sea surface temperatures used to calibrate infrared satellite measurements|page=2387|issue=C2|bibcode=2001JGR...106.2387E|doi=10.1029/2000JC000246|doi-access=free}}</ref>  The satellite measurement is made by sensing the ocean [[radiation]] in two or more wavelengths within the [[infrared]] part of the [[electromagnetic spectrum]] or other parts of the spectrum which can then be empirically related to SST.<ref name="John">{{cite web|url=http://www2.hawaii.edu/~jmaurer/sst/|title=Infrared and microwave remote sensing of sea surface temperature (SST)|author=John Maurer|date=October 2002|publisher=[[University of Hawai{{okina}}i]]|access-date=2011-01-09}}</ref> These wavelengths are chosen because they are:

# within the peak of the [[blackbody radiation]] expected from the Earth,<ref>{{cite journal|url=http://www.wamis.org/agm/pubs/agm8/Paper-4.pdf|page=73|journal=Satellite Remote Sensing and GIS Applications in Agricultural Meteorology|title=Meteorological Satellites|author=C. M. Kishtawal|date=2005-08-06|access-date=2011-01-27|archive-date=2020-02-15|archive-url=https://web.archive.org/web/20200215044026/http://www.wamis.org/agm/pubs/agm8/Paper-4.pdf|url-status=dead}}</ref> and
# able to transmit adequately well through the [[Earth's atmosphere|atmosphere]]<ref>{{cite journal|journal=New Scientist|date=1971-09-16|title=Mapping the Atmosphere From Space|author= Robert Harwood|page=623|volume=51|issue=769}}</ref>

The satellite-measured SST provides both a [[synoptic scale|synoptic view]] of the ocean and a high frequency of repeat views,<ref>{{cite book|page=510|url=https://books.google.com/books?id=Y0iX2z48qkUC&pg=PA509|author1=David E. Alexander |author2=Rhodes Whitmore Fairbridge |title=Encyclopedia of environmental science|year=1999|publisher=Springer|isbn=978-0-412-74050-3}}</ref> allowing the examination of basin-wide upper [[ocean]] dynamics not possible with ships or buoys. <span class="plainlinks">[http://www.nasa.gov/ NASA's]</span> (National Aeronautic and Space Administration) <span class="plainlinks">[http://modis.gsfc.nasa.gov/ Moderate Resolution Imaging Spectroradiometer (MODIS)]</span> SST satellites have been providing global SST data since 2000, available with a one-day lag. NOAA's <span class="plainlinks">[http://www.goes.noaa.gov/ GOES (Geostationary Orbiting Earth Satellites)] {{Webarchive|url=https://web.archive.org/web/20200817111624/http://www.goes.noaa.gov/ |date=2020-08-17 }}</span> satellites are [[geostationary orbit|geo-stationary]] above the Western Hemisphere which enables them to deliver SST data on an hourly basis with only a few hours of lag time.

There are several difficulties with satellite-based absolute SST measurements. First, in infrared remote sensing methodology the radiation emanates from the [[Sea surface microlayer|top "skin" of the ocean]], approximately the top 0.01 [[millimetre|mm]] or less, which may not represent the [[bulk temperature]] of the upper meter of ocean due primarily to effects of solar surface heating during the daytime, reflected radiation, as well as sensible heat loss and surface evaporation. All these factors make it somewhat difficult to compare satellite data to measurements from buoys or shipboard methods, complicating ground truth <!-- clarify -->efforts.<ref>{{cite book|url=https://books.google.com/books?id=jk1fIo51uwMC&pg=PA278|page=279|author=Ian Stuart Robinson|title=Measuring the oceans from space: the principles and methods of satellite oceanography|publisher=Springer|year=2004|isbn=978-3-540-42647-9}}</ref>  Secondly, the satellite cannot look through clouds, creating a cool bias in satellite-derived SSTs within cloudy areas.<ref name="space"/>  However, passive microwave techniques can accurately measure SST and penetrate cloud cover.<ref name="John"/>  Within atmospheric sounder channels on [[weather satellite]]s, which peak just above the ocean's surface, knowledge of the sea surface temperature is important to their calibration.<ref name="space"/>