LakeSST: Lake Skin Surface Temperature
Version 1.2 (February 2018)

The LakeSST data set contains skin surface temperature data for 442 French 
water bodies (natural lakes, reservoirs, ponds, gravel pit lakes and quarry
lakes) for the period 1999-2016 obtained from archive thermal band images
taken by Landsat 5 TM and Landsat 7 ETM+.

Updates since version 1.0
------------------------
Version 1.1 (unpublished):
- Addition of data for water body LEM74 for 1999-2015, which were absent by
mistake in the version 1.0.

Version 1.2:
- Addition of lake names to the 01_lake_data.txt file.
- Addition of missing data for several water bodies.
- Following a referee's comment to our discussion paper on LakeSST
(https://www.earth-syst-sci-data-discuss.net/essd-2017-133/#discussion),
we have filtered out all measurements affected by clouds, characterised by a
clearness index < 0.6.

Content of the data set
-----------------------
The data set consists of 3 files:
*) 00_Read_me.txt: this file;
*) 01_lake_data.txt: it contains data on the characteristics of the lakes
included in the data set;
*) 02_LakeSST_data.zip: it contains 442 skin surface temperature files
("lake code".txt), one for each water body.

Lake data
---------
The file 01_lake_data.txt contains 8 columns summarizing the characteristics
of the lakes in the data set. The information was extracted from the French
lake database (PLAN_DEAU) maintained by the AFB-Irstea Pole on Water Bodies
Hydroecology at Aix-en-Provence (France). The column names and descriptions
are:
*) Lake_code: alphanumeric code identifying each lake;
*) Longitude_deg: decimal longitude in degrees;
*) Latitude_deg: decimal latitude in degrees;
*) Altitude_m: altitude in metres;
*) Depth_m: maximum depth in metres;
*) Surface_m2: surface area in square metres;
*) Volume_m3: volume in cubic metres;
*) WBType: type of water body (C: quarry lake; E: pond; G: gravel pit lake;
LN: natural lake; R: reservoir);
*) Lake_name: lake name in French.

Skin surface temperature data
-----------------------------
The skin surface temperature data are included in the compressed file
02_LakeSST_data.zip. Skin surface temperatures were calculated using the 
single-channel algorithm developed by Jiménez-Muñoz et al. (2009). Details
of the calculation and quality of the data set are described in Simon et al.
(2014) and, especially, in a data paper by Prats et al. (doi:
10.5194/essd-2017-133).
The surface temperature files contain summary statistics for each satellite
image with valid measurements in 1999-2016. The data columns are the
following:
*) Date: date in the format yyyy/mm/dd;
*) Hour: hour at which the satellite image was taken, in the format hh:mm;
*) Npixels: number of valid pixels;
*) Tmedian: median temperature (ºC);
*) Tmean: mean temperature (ºC);
*) StdT: standard deviation (ºC);
*) Tmin: minimum temperature (ºC);
*) Tmax: maximum temperature (ºC);
*) T25: 25 % quartile (ºC);
*) T75: 75 % quartile (ºC);
*) satellite: satellite/instrument that took the image (lt5: Landsat 5 TM;
le7: Landsat 7 ETM+);
*) path/row: path and row of the corresponding satellite image.

References
----------
*) Jiménez-Muñoz, J. C.; Cristóbal, J.; Sobrino, J. A.; Sòria, G.;
Ninyerola, M.; Pons, X. 2009. Revision of the single-channel algorithm for
land surface temperature retrieval from Landsat thermal-infrared data. IEEE
Transactions on Geoscience and Remote Sensing, 47(1), 339-349.
doi: 10.1109/TGRS.2008.2007125.
*) Prats, J.; Reynaud, N.; Rebière, D.; Peroux, T.; Tormos, T.; Danis, P.-A.
2017. LakeSST: Lake Skin Surface Temperatures in French inland water bodies
for 1999-2016 from Landsat archives. Earth System Science Data Discussions.
doi: 10.5194/essd-2017-133.
*) Simon, R. N.; Tormos, T.; Danis, P.-A. 2014. Retrieveing water surface
temperature from archive LANDSAT thermal infrared data: Application of the
mono-channel atmospheric algorithm over two freshwater reservoirs.
International Journal of Applied Earth Observation and Geoinformation, 30,
247-250. doi: 10.1016/j.jag.2014.01.005.

Authors and contacts
--------------------
Jordi Prats (jordi.prats@irstea.fr, jordipratsrodriguez@gmail.com)
Nathalie Reynaud (nathalie.reynaud@irstea.fr)
Thierry Tormos (thierry.tormos@afbiodiversite.fr)
Pierre-Alain Danis (pierre-alain.danis@afbiodiversite.fr)

AFB-Irstea Pole on Water Bodies Hydroecology, Irstea
3275 Route de Cézanne,
13182 Aix-en-Provence,
France
