GISS Surface Temperature Analysis

Global Maps from GHCN v3 Data

Select parameters on the following form to create a surface temperature anomaly or trend map. An explanation of the input elements appears at the bottom of this page. Note that generating figures takes 5 or 6 seconds; please be patient .

Data Sources: Land:
Ocean:
Map Type:
Mean Period:
Time Interval: Begin — End
Base Period: Begin — End
Smoothing Radius:
Map Projection:
 

Notes Concerning the Maps:

  • The number at the top right-hand corner of the map plot is an estimate for the global mean of the calculated field; it may be somewhat different from the GISTEMP index because an alternative method is used to deal with missing data. See the FAQ for further explanation. Note that if the map only shows ocean data (Land: none), the mean is computed only over the area with data.
  • The end points of the color bar have defaults (-4.1°, 4.1°). Either or both is replaced if the min and/or max value of the data is outside that range.

Input Elements:

  • Data Sources: Land
  • Data Sources: Ocean
    • None: NO ocean temperature data are used
    • ERSST_v3b: NOAA/NCEI's Extended Reconstructed Sea Surface Temperature (ERSST) v. 3b
    • ERSST_v4: NOAA/NCEI's Extended Reconstructed Sea Surface Temperature (ERSST) v. 4
    • Hadl/Reyn_v2: SST 1880-present -- 1880-11/1981: Hadley HadISST1, ship and buoy data (Rayner 2000); 12/1981-present: OISST v. 2, satellite data (Reynolds-Rayner-Smith 2001)
  • Map type:
    • Anomalies: Mean temperature (°C) averaged over a specified mean period and time interval relative to a given base period.
    • Trends: Temperature change of a specified mean period over a specified time interval based on local linear trends.
  • Mean period: Any monthly, seasonal (3 month or 6 month) or annual mean.
    Period is declared missing, unless >50% of data are available.
  • Time interval: Years over which temperatures are averaged or trends are found.
    Note: If the mean period straddles 2 years, fill in the LATER year for both Begin AND End.
    Periods may not start before Jan 1880.
    'Means' are not reported unless >50% of the needed records are available,
    'Trends' are not reported unless >66% of the needed records are available.
  • Base period: Time interval to which anomalies are relative. This input is not used for trend maps.
  • Smoothing radius: Distance over which a station influences regional temperature, either 250 km or 1200 km (standard case = 1200 km).

References:

Please see the GISTEMP references page for citations to publications related to this research.

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