World Map of the Koppen-Geiger Climate Classification

A new global map of climate classifications using the Koppen-Geiger system has been produced based on a large global data set of long-term monthly precipitation and temperature station time series.

To construct the new map, long-term station records of monthly precipitation and monthly temperature were obtained from the Global Historical Climatology Network (GHCN) version 2.0 data set (Peterson and Vose, 1997). Stations from this data set with at least 30 observations for each month were used in the analysis (12,396 precipitation and 4,844 temperature stations). The data are most representative from 1909 to 1991 for precipitation and 1923 to 1993 for temperature. Climatic variables were interpolated between stations in ESRI ArcMap version 9.1 using a two-dimensional (latitude and longitude) thin-plate spline with tension onto a 0.1 x 0.1 degree grid for each continent. The Koppen-Geiger criteria were then applied to the splined variables.

The Koppen-Geiger system includes 30 possible climate types. They are divided
into 3 tropical (Af, Am and Aw), 4 arid (BWh, BWk, BSh and BSk), 9 temperate (Csa,
Csb, Csc, Cfa, Cfb, Cfc, Cwa, Cwb and Cwc), 12 cold (Dsa, Dsb, Dsc, Dsd, Dfa, Dfb,
Dfc, Dfd, Dwa, Dwb, Dwc and Dwd) and 2 polar (ET and EF) (The source document and metadata record define the subdivisions). All precipitation variables are in units of millimetres (mm) and all temperature variables are in units of degrees Celsius (C).

Koppen-Geiger climate type maps were constructed for each continent and the
percentage of land area covered by the major climate types was calculated. Since the
area of a 0.1 x 0.1 degree pixel changes with latitude, a map of 0.1 x 0.1 degree pixel
area was constructed and then projected onto a Cylindrical Equal Area projection of
the world to determine the area (in km2) of each 0.1 x 0.1 degree pixel. These pixel
areas were then summed for each climate type to provide an estimate of the land area covered by each climate type. The continental maps are presented and discussed in Peel et al. (2007). The global map is available for download in ESRI Arc Grid.

Oak Ridge National Laboratory (ORNL) also provides the updated World Map of the Koppen-Geiger Climate Classification, but in GeoTiff format. ORNL Convert data from ESRI Grid format to GeoTIFF format. The processed GeoTIFF data were fed into ORNL DAAC Web Map Service v1.1.1 (WMS), Web Coverage Service v1.0.0 (WCS), and Spatial Data Access Tool (SDAT) to provide data visualization and distribution capabilities.
References:

Koppen, W. 1936. Das geographisca System der Klimate, in: Handbuch der Klimatologie, edited by: K¨oppen, W. and Geiger, G., 1. C. Gebr, Borntraeger, 1â�“44.

Peel, M. C., B. L. Finlayson, and T. A. McMahon. 2007. Updated World Map of the Koppen-Geiger Climate Classification. Hydrol. Earth Syst. Sci., 11, 1633-1644. doi:10.5194/hess-11-1633-2007.

Peterson, T.C., and R.S. Vose. 1997. An overview of the Global Historical Climatology Network temperature database, Bull. Am. Meteorol. Soc., 78(12), 2837�2849.

本研究依托全球长期月度降水与气温台站时间序列大型数据集，构建了一套全新的柯本-盖格（Koppen-Geiger）气候分类全球地图。

为构建该新版地图，研究数据取自全球历史气候学网络（Global Historical Climatology Network, GHCN）2.0版本数据集（Peterson与Vose, 1997）中的长期台站记录，筛选出各月观测记录不少于30条的台站用于分析，其中降水台站共12396个，气温台站共4844个。该数据在降水方面的代表性时段为1909年至1991年，气温方面则为1923年至1993年。研究借助ESRI ArcMap 9.1版本软件，采用带张力的二维（经纬度）薄板样条插值法，将台站数据插值至各大陆0.1°×0.1°的网格中，随后对插值得到的变量应用柯本-盖格分类标准。

柯本-盖格气候分类系统共包含30种潜在气候类型，可划分为5大类：3种热带气候（Af、Am、Aw）、4种干旱气候（BWh、BWk、BSh、BSk）、9种温带气候（Csa、Csb、Csc、Cfa、Cfb、Cfc、Cwa、Cwb、Cwc）、12种寒冷气候（Dsa、Dsb、Dsc、Dsd、Dfa、Dfb、Dfc、Dfd、Dwa、Dwb、Dwc、Dwd）以及2种极地气候（ET、EF）（原始文献与元数据记录对各子类均有明确定义）。所有降水变量单位均为毫米（mm），气温变量单位均为摄氏度（℃）。

研究针对各大陆分别构建了柯本-盖格气候类型地图，并计算了主要气候类型所占的陆地面积百分比。由于0.1°×0.1°网格像元的面积随纬度变化，因此首先构建了0.1°×0.1°像元面积地图，随后将其投影至圆柱等面积投影世界坐标系中，以计算每个像元的面积（单位：平方千米）。最后将各气候类型对应的像元面积求和，得到各气候类型所覆盖的陆地面积估算值。各大陆的气候地图已在Peel等人（2007）的研究中进行了展示与讨论，全球地图可通过ESRI Arc Grid格式下载。

橡树岭国家实验室（Oak Ridge National Laboratory, ORNL）还提供了更新版的柯本-盖格气候分类世界地图，格式为GeoTIFF。该实验室将数据从ESRI Grid格式转换为GeoTIFF格式，处理后的GeoTIFF数据被接入ORNL DAAC的Web地图服务（Web Map Service, WMS）v1.1.1、Web覆盖服务（Web Coverage Service, WCS）v1.0.0以及空间数据访问工具（Spatial Data Access Tool, SDAT），以实现数据可视化与分发功能。

参考文献：
Koppen, W. 1936. 《气候的地理系统》，收录于《气候学手册》，编辑：Koppen, W. 与Geiger, G.，第1卷，C. Gebr, Borntraeger，1–44。
Peel, M. C., B. L. Finlayson, 与T. A. McMahon. 2007. 《柯本-盖格气候分类世界更新地图》. Hydrol. Earth Syst. Sci., 11, 1633-1644. doi:10.5194/hess-11-1633-2007。
Peterson, T.C., 与R.S. Vose. 1997. 《全球历史气候学网络气温数据库概述》, Bull. Am. Meteorol. Soc., 78(12), 2837–2849。