CHELSA Bioclim
Bioclimatic variables are derived variables from the monthly mean, max, mean temperature, and mean precipitation values. They are developed for species distribution modeling and related ecological applications. They represent annual trends (e.g., mean annual temperature, annual precipitation) seasonality (e.g., annual range in temperature and precipitation) and extreme or limiting environmental factors (e.g., temperature of the coldest and warmest month, and precipitation of the wet and dry quarters). A quarter is defined as a period of three months (1/4 of the year). The code follows those of Worldclim and ANUCLIM
When using the data, you agree to cite the respective original peer-reviewed publication AND the respective dataset (Why are data citations neccessary?):
Karger, D.N., Conrad, O., Böhner, J., Kawohl, T., Kreft, H., Soria-Auza, R.W., Zimmermann, N.E., Linder, P., Kessler, M. (2017). Climatologies at high resolution for the Earth land surface areas. Scientific Data. 4 170122. https://doi.org/10.1038/sdata.2017.122
Karger D.N., Conrad, O., Böhner, J., Kawohl, T., Kreft, H., Soria-Auza, R.W., Zimmermann, N.E,, Linder, H.P., Kessler, M.. Data from: Climatologies at high resolution for the earth’s land surface areas. Dryad Digital Repository.http://dx.doi.org/doi:10.5061/dryad.kd1d4
THE LAYERS CAN BE DOWNLOADED HERE
Additional information can be found here:
CHELSA V2.1: Technical specifications.
The following layers are available:
shortname |
longname |
unit |
scale |
offset |
explanation |
bio1 |
mean annual air temperature |
°C |
0.1 |
-273.15 |
mean annual daily mean air temperatures averaged over 1 year |
bio2 |
mean diurnal air temperature range |
°C |
0.1 |
0 |
mean diurnal range of temperatures averaged over 1 year |
bio3 |
isothermality |
°C |
0.1 |
0 |
ratio of diurnal variation to annual variation in temperatures |
bio4 |
temperature seasonality |
°C/100 |
0.1 |
0 |
standard deviation of the monthly mean temperatures |
bio5 |
mean daily maximum air temperature of the warmest month |
°C |
0.1 |
-273.15 |
The highest temperature of any monthly daily mean maximum temperature |
bio6 |
mean daily minimum air temperature of the coldest month |
°C |
0.1 |
-273.15 |
The lowest temperature of any monthly daily mean maximum temperature |
bio7 |
annual range of air temperature |
°C |
0.1 |
0 |
The difference between the Maximum Temperature of Warmest month and the Minimum Temperature of Coldest month |
bio8 |
mean daily mean air temperatures of the wettest quarter |
°C |
0.1 |
-273.15 |
The wettest quarter of the year is determined (to the nearest month) |
bio9 |
mean daily mean air temperatures of the driest quarter |
°C |
0.1 |
-273.15 |
The driest quarter of the year is determined (to the nearest month) |
bio10 |
mean daily mean air temperatures of the warmest quarter |
°C |
0.1 |
-273.15 |
The warmest quarter of the year is determined (to the nearest month) |
bio11 |
mean daily mean air temperatures of the coldest quarter |
°C |
0.1 |
-273.15 |
The coldest quarter of the year is determined (to the nearest month) |
bio12 |
annual precipitation amount |
kg m-2 |
0.1 |
0 |
Accumulated precipitation amount over 1 year |
bio13 |
precipitation amount of the wettest month |
kg m-2 |
0.1 |
0 |
The precipitation of the wettest month. |
bio14 |
precipitation amount of the driest month |
kg m-2 |
0.1 |
0 |
The precipitation of the driest month. |
bio15 |
precipitation seasonality |
kg m-2 |
0.1 |
0 |
The Coefficient of Variation is the standard deviation of the monthly precipitation estimates expressed as a percentage of the mean of those estimates (i.e. the annual mean) |
bio16 |
mean monthly precipitation amount of the wettest quarter |
kg m-2 |
0.1 |
0 |
The wettest quarter of the year is determined (to the nearest month) |
bio17 |
mean monthly precipitation amount of the driest quarter |
kg m-2 |
0.1 |
0 |
The driest quarter of the year is determined (to the nearest month) |
bio18 |
mean monthly precipitation amount of the warmest quarter |
kg m-2 |
0.1 |
0 |
The warmest quarter of the year is determined (to the nearest month) |
bio19 |
mean monthly precipitation amount of the coldest quarter |
kg m-2 |
0.1 |
0 |
The coldest quarter of the year is determined (to the nearest month) |
gdgfgd0 |
First growing degree day above 0°C |
julian day |
– |
– |
First day of the year above 0°C |
gdgfgd5 |
First growing degree day above 5°C |
julian day |
– |
– |
First day of the year above 5°C |
gdgfgd10 |
First growing degree day above 10°C |
julian day |
– |
– |
First day of the year above 10°C |
fcf |
Frost change frequency |
count |
– |
– |
Number of events in which tmin or tmax go above, or below 0°C |
gdd0 |
Growing degree days heat sum above 0°C |
°C |
0.1 |
0 |
heat sum of all days above the 0°C temperature accumulated over 1 year. |
gdd5 |
Growing degree days heat sum above 5°C |
°C |
0.1 |
0 |
heat sum of all days above the 5°C temperature accumulated over 1 year. |
gdd10 |
Growing degree days heat sum above 10°C |
°C |
0.1 |
0 |
heat sum of all days above the 10°C temperature accumulated over 1 year. |
gddlgd0 |
Last growing degree day above 0°C |
julian day |
– |
– |
Last day of the year above 0°C |
gddlgd5 |
Last growing degree day above 5°C |
julian day |
– |
– |
Last day of the year above 5°C |
gddlgd10 |
Last growing degree day above 10°C |
julian day |
– |
– |
Last day of the year above 10°C |
gsl |
growing season length TREELIM |
number of days |
– |
– |
Length of the growing season |
gsp |
Accumulated precipiation amount on growing season days TREELIM |
kg m-2 |
0.1 |
0 |
precipitation sum accumulated on all days during the growing season based on TREELIM (https://doi.org/10.1007/s00035-014-0124-0) |
gst |
Mean temperature of the growing season TREELIM |
°C |
0.1 |
-273.15 |
Mean temperature of all growing season days based on TREELIM (https://doi.org/10.1007/s00035-014-0124-0) |
lgd |
last day of the growing season TREELIM |
julian day |
– |
– |
Last day of the growing season according to TREELIM (https://doi.org/10.1007/s00035-014-0124-0) |
fgd |
first day of the growing season TREELIM |
julian day |
– |
– |
first day of the growing season according to TREELIM (https://doi.org/10.1007/s00035-014-0124-0) |
ngd0 |
Number of growing degree days |
number of days |
– |
– |
Number of days at which tas > 0°C |
ngd5 |
Number of growing degree days |
number of days |
– |
– |
Number of days at which tas > 5°C |
ngd10 |
Number of growing degree days |
number of days |
– |
– |
Number of days at which tas > 10°C |
kg0 |
Köppen-Geiger climate classification |
category |
– |
– |
Köppen Geiger
Koeppen, W., Geiger, R. (1936): Handbuch der Klimatologie. Gebrüder Borntraeger, Berlin. Wikimedia. |
kg1 |
Köppen-Geiger climate classification |
category |
– |
– |
Köppen Geiger without As/Aw differentiation
Koeppen, W., Geiger, R. (1936): Handbuch der Klimatologie. Gebrüder Borntraeger, Berlin. Wikimedia. |
kg2 |
Köppen-Geiger climate classification |
category |
– |
– |
Köppen Geiger after Peel et al. 2007
Peel, M. C., Finlayson, B. L., McMahon, T. A. (2007): Updated world map of the Koeppen-Geiger climate classification. Hydrology and earth system sciences discussions, 4(2), 439-473. Free Access. |
kg3 |
Köppen-Geiger climate classification |
category |
– |
– |
Wissmann 1939
Wissmann, H. (1939): Die Klima-und Vegetationsgebiete Eurasiens: Begleitworte zu einer Karte der Klimagebiete Eurasiens. Z. Ges. Erdk. Berlin, p.81-92. |
kg4 |
Köppen-Geiger climate classification |
category |
– |
– |
Thornthwaite 1931
Thornthwaite, C. W. (1931): The climates of North America: according to a new classification. Geographical review, 21(4), 633-655. JSTOR. |
kg5 |
Köppen-Geiger climate classification |
category |
– |
– |
Troll-Pfaffen
Troll, C. & Paffen, K.H. (1964): Karte der Jahreszeitenklimate der Erde. Erdkunde 18, p5-28 Free Access. |
scd |
Snow cover days |
count |
– |
– |
Number of days with snowcover calculated using the snowpack model implementation in from TREELIM (https://doi.org/10.1007/s00035-014-0124-0) |
swe |
Snow water equivalent |
kg m-2 |
0.1 |
0 |
Amount of luquid water if snow is melted |
npp |
Net primary productivity |
g C m−2 yr−1 |
0.1 |
0 |
Calculated based on the ‘Miami model’, Lieth, H., 1972. “Modelling the primary productivity of the earth. Nature and resources”, UNESCO, VIII, 2:5-10. |
pr |
precipitation amount |
kg m-2 |
0.1 |
0 |
“Amount” means mass per unit area. “Precipitation” in the earth’s atmosphere means precipitation of water in all phases. |
tasmax |
mean daily maximum 2m air temperature |
°C |
0.1 |
-273.15 |
daily maximum air temperatures at 2 metres from hourly ERA5 data |
tas |
mean daily air temperature |
°C |
0.1 |
-273.15 |
daily mean air temperatures at 2 metres from hourly ERA5 data |
tasmin |
mean daily minimum air temperature |
°C |
0.1 |
-273.15 |
daily minimum air temperatures at 2 metres from hourly ERA5 data |