Global surface temperature data: MLOST: NOAA Merged Land-Ocean Surface Temperature Analysis

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Global surface temperature data: MLOST: NOAA Merged Land-Ocean Surface Temperature Analysis
Main content

NOAA's Merged Land-Ocean Surface Temperature Analysis (MLOST) combines land surface air temperatures primarily from the Global Historical Climatology Network, Monthly (GHCN-M) version 3 with SSTs of the ERSSTv3b analysis into a comprehensive global surface temperature data set spanning 1880 to the present at monthly resolution, on a 5x5 degree latitude-longitude grid. As such, it is one of the main data sets used to monitor global and regional temperature variability and trends. Like GISTEMP, interpolation of the station records is performed to provide broad spatial coverage, however, the methodology is unique. Land and ocean domains are treated separately. For both domains, high and low-frequency variations are reconstructed separately using empirical orthogonal functions, and these signals are combined and blended with the original records. The final step involves combining the land and ocean data sets into one; over coastal regions land and ocean values are weighted in proportion to the amount of land or ocean in the 5x5 degree box. Data-sparse areas are masked to prevent reliance on the highly smoothed reconstruction estimates. Sea ice areas are also set to missing. 

Key Strengths

Key Strengths

Incorporates the most recent processing of GHCN (v3)

Key Limitations

Key Limitations

Limited coverage of polar regions

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Suggested Data Citation
Dataset DOIs
Hosted Climate Index Files
Usage Restrictions

Key Figures

Change of temperature in the MLOST data set. credit: Climate Data Guide

Change of annual mean temperatures between 1901:1920 and 1991:2010 based on the NOAA MLOST dataset. Credit: ClimateDataGuide, NCAR

Other Information

Earth system components and main variables
Type of data product

Years of record
Data time period extended
Yes, data set is extended
Input Data

GHCN v3.3 (~7000 land stations); ERSSTv3b (SSTs)

Vertical Levels:
Missing Data Flag
Missing data present
Ocean or Land
Ocean & Land
Spatial Resolution

5x5 degrees

Model Resolution (reanalysis)
Data Assimilation Method
Model Vintage (reanalysis)