Bioclim

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

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