Globolakes : Data

Data Products

Latest News

18/12/2018 ARC-Lake v3.0 dataset has been archived at the University of Reading Data Archive ARC-Lake v3 and can be cited as
Merchant, C. J. and MacCallum, S. N. (2018): Lake Surface Water Temperature ARC-Lake v3 (1995-2012). University of Reading. Dataset.
10/03/2014 A new project Globolakes has started. See the Globolakes section of this website.
20/12/2013 Additional ARC-Lake v3.0 data products (averaged products and full resolution water masks) added to this website.
Note, that data on the Data Visualization page are still v2.0 (20/12/13).
24/10/2013 ARC-Lake v3.0 data products released on this website.
30/05/2012 ARC-Lake v2.0 data products released. These are available at the Edinburgh DataShare (
08/12/2011 ARC-Lake v1.1.2 data products made available on the Edinburgh DataShare (
15/04/2011 ARC-Lake Database and lake-mean LSWT products available at Google Fusion Tables (See Data Visualizations for details). New versions (v1.1.2) of some averaged data products released (see ARC-Lake DPD v1.1.2 doc for details)
31/03/2011 New versions (v1.1.1) of some averaged data products released (see ARC-Lake DPD v1.1.1 doc for details)
22/03/2011 Version v1.1 data products released
22/09/2010 Version v1.0 data products released



The latest version of official data products (v3.0) from the ARC-Lake project are now available for download from this site and they have been archived at the University of Reading Reaserch Data Archive (ARC-Lake v3).

The ARC-Lake v2.0 data products are available for download from the Edinburgh DataShare (

ARC-Lake v2.0/v3.0 data products may be downloaded and used freely, but we ask that the dataset is referenced if used in any publications. Please reference as:

(v2.0) MacCallum, S. N., and Merchant, C. J. (2013). ARC-Lake v2.0, 1991-2011 [Dataset]. University of Edinburgh, School of GeoSciences / European Space Agency,

(v3.0) Merchant, C. J. and MacCallum, S. N. (2018). Lake Surface Water Temperature ARC-Lake v3 (1995-2012). University of Reading. Dataset.

The methodolgy used to create these data products is outlined in the following paper:
MacCallum, S. N. and C. J. Merchant (2012), Surface Water Temperature Observations of Large Lakes by Optimal Estimation, Can J Remote Sensing, 38(1), 25 - 45. doi:10.5589/m12-010. Available online.

A number of different types of data product are available, from gridded observations on a lake-by-lake basis to global climatology. Data products derived from spatially complete reconstructions are available alongside those derived directly from the ARC-Lake observations. A summary of the possible variants is given below. Note that not all possible combinations are availble.


Table 1. Summary of possible ARC-Lake data files
  Possible variants


Mailing List

We ask that you e-mail if you download ARC-Lake data, indicating your intended usage. This is in order that we can monitor our number of users and keep you informed about how to cite the data in any publications.



The contents and structure of all v3.0 data products are detailed in the ARCLake Data Product Description (ARC-Lake DPD).

This document also includes the list of lakes and their corresponding IDs. This list can also be found in the ARC Lakes section of this website.

Data are available for download in a set of zip archives, containing multiple data products. A full listing of the contents of each zip archive is given in the ARCLake Data Product File Lists document (ARC-Lake DPFL).

Supplementary documents describing the methods used, lake definition, and validation results for v3.0 observations are also available:


Land/Water Masks

Global land/water masks for the ARC-Lake v3 targets are also available for download. These are available on both the ARC-Lake product resolution (0.05o) and the higher resolution (0.00833o) used during the LSWT processing. Two types of mask are provided at each resolution: a mask of the maximum water area over the ATSR2/AATSR time period, and annual masks of the minimum water area. These are used for day-time and night-time ARC-Lake LSWT retrievals respectively (see Technical Note 2 and the ATBD for further details). All masks are derived from the results of a water detection algorithm applied to both ATSR2 and AATSR. All land water masks are stored in compressed NetCDF4 format.

The following file naming convention is used for the maximum and minimum area masks:

  • Max. =
  • Min. =

where XXX represents the grid resolution as a fraction of a degree (e.g. 1/20o is given by 020) and YYYY is the year over which the minimum area mask applies.

1/20o resolution (product resolution)

Product Long Name Download File Size (MB) Uncompressed Size (MB)

The maximum area file contains the following data on a 2-D global grid:

  • lakeid - land/lake mask
  • flagmix - indicates if cell contains more than one lake
  • nwater - number of lake cells on the high resolution (0.00833o) land/water mask used in the processing

The minimum area files only contain a binary mask on the 2-D global grid:

  • water - land/lake mask (water cells are set to 1)

Please note that this land/water mask only includes the targets listed in the Targets section of this website.

1/120o resolution (processing resolution)

The full resolution (0.00833o) land/water masks as used in the v3.0 ARC-Lake processing are also available for download.

Product Long Name Download File Size (MB) Uncompressed Size (MB)

As with the product resolution masks, the maximum are mask at the processing resolution contains the target IDs, while the minimum area products contain only a binary land/water mask.


Data Readers

Basic code for reading in the NetCDF files is available for IDL and MATLAB. These functions will read the entire contents of the named NetCDF file, returning them as a structure. In both cases, the data is read in using the same function call:

data = read_netcdf_all(filename)

Software Package Code Download

An add-in for Microsoft Excel 2007, to enable NetCDF files to be read in, is available for download at

Please note that this is limited by Excel's memory limitations so is not recommended for large files (e.g. spatially resolved time-series products for the Caspian Sea).

A list of software for manipulating or displaying NetCDF data is available at


Archived Docs

Algorithm Theoretical Basis Document (ATBD) - v1
Technical Note 1: Lake Definition and Validation Strategy
Validation Report - v1.0
ARCLake Data Product File Lists v1.1.2
ARC-Lake Data Product Description v1.1.2
ARC-Lake Data Product Description v1.1.1
ARC-Lake Data Product Description v1.1
ARC-Lake Data Product Description v1.0



If you have any questions about the ARCLake data available on this page, please email .