气象CDO：数据处理与运算工具详解

需积分: 50 200 浏览量更新于2024-07-21 7 收藏 1.36MB PDF 举报

气象CDO（Climate Data Operators）是一种强大的工具，用于处理和分析气象数据，特别是对于地球科学和气候研究领域至关重要。CDO的功能包括但不限于： 1. 数据提取与合并：用户可以根据特定的时间、空间范围以及经纬度坐标，从大量的气象数据库或文件中提取所需的数据，并将其合并成一个统一的格式，便于后续分析。 2. 数据运算：CDO提供了丰富的算术运算，如加减乘除，以及统计量计算，如方差、均方差、和、极值、滑动窗口统计（滑动均值、滑动方差、滑动极值）、区域平均、区域方差和区域极值，这些都是对气候数据进行初步处理和清洗的重要步骤。 3. 统计分析：CDO支持复杂的统计运算，如相关性分析、线性回归，甚至 EOF（Empirical Orthogonal Functions）分析，这是探索气候变化模式和趋势的关键方法。滤波和插值功能则用于减少噪声和提高数据的空间分辨率。 4. 数据格式转换：CDO允许在不同的数据格式之间转换，例如将binary格式转换为netCDF (Network Common Data Form) 或 HDF (Hierarchical Data Format)，这对于数据共享和跨平台使用极其便利。 5. 气候指数运算：针对极端天气事件等气候现象，CDO能够执行相关的气候指数运算，帮助科学家评估气候事件的频率和强度。 CDO的核心理念是提供一个直观且高效的命令行工具，使得用户能够通过一系列参数选项来定制和执行操作，无需深入理解底层代码。它还支持网格操作，如定义格子权重、描述网格结构，以及对Z轴（垂直方向）和时间轴的精确控制，确保了数据处理的准确性和一致性。参考手册详细介绍了CDO的各种功能，包括查看数据信息、比较数据、打印参数数量、显示变量和时间信息，以及文件操作如复制、替换和数据复制等。这些功能使得CDO成为气象科学家、气候模型开发者以及相关领域的研究人员不可或缺的实用工具。气象CDO是一款功能强大的气候数据分析工具，通过其丰富的操作和灵活的格式转换功能，为气候科学研究提供了高效的数据处理手段，有助于揭示气候变化的深层次规律。

2. Reference manual

This section gives a description of all operators. Related operators are grouped to modules. For easier

description all single input ﬁles are named ifile or ifile1, ifile2, etc., and an unlimited number of

input ﬁles are named ifiles. All output ﬁles are named ofile or ofile1, ofile2, etc. Further the

following notion is introduced:

i(t) Timestep t of ifile

i(t, x) Element number x of the ﬁeld at timestep t of ifile

o(t) Timestep t of ofile

o(t, x) Element number x of the ﬁeld at timestep t of ofile

Information Reference manual

2.1.1. INFO - Information and simple statistics

Synopsis

<operator > ifiles

Description

This module writes information about the structure and contents of all input ﬁles to standard output.

All input ﬁles need to have the same structure with the same variables on diﬀerent timesteps. The

information displayed depends on the chosen operator.

Operators

info Dataset information listed by parameter identiﬁer

Prints information and simple statistics for each ﬁeld of all input datasets. For each ﬁeld

the operator prints one line with the following elements:

• Date and Time

• Level, Gridsize and number of Missing values

• Minimum, Mean and Maximum

The mean value is computed without the use of area weights!

• Parameter identiﬁer

infon Dataset information listed by parameter name

The same as operator info but using the name instead of the identiﬁer to label the param-

eter.

map Dataset information and simple map

Prints information, simple statistics and a map for each ﬁeld of all input datasets. The

map will be printed only for ﬁelds on a regular lon/lat grid.

Example

To print information and simple statistics for each ﬁeld of a dataset use:

cdo infon ifile

This is an example result of a dataset with one 2D parameter over 12 timesteps:

−1 : Date Time L ev el S i z e Miss : Minimum Mean Maximum : Name

1 : 1987−01−31 1 2 : 00 : 0 0 0 2048 1361 : 23 2. 77 26 6. 65 30 5. 31 : SST

2 : 1987−02−28 1 2 : 00 : 0 0 0 2048 1361 : 23 3. 64 26 7. 11 30 7. 15 : SST

3 : 1987−03−31 1 2 : 00 : 0 0 0 2048 1361 : 22 5. 31 26 7. 52 30 7. 67 : SST

4 : 1987−04−30 1 2 : 00 : 0 0 0 2048 1361 : 21 5. 68 26 8. 65 31 0. 47 : SST

5 : 1987−05−31 1 2 : 00 : 0 0 0 2048 1361 : 21 5. 78 27 1. 53 31 2. 49 : SST

6 : 1987−06−30 1 2 : 00 : 0 0 0 2048 1361 : 21 2. 89 27 2. 80 31 4. 18 : SST

7 : 1987−07−31 1 2 : 00 : 0 0 0 2048 1361 : 20 9. 52 27 4. 29 31 6. 34 : SST

8 : 1987−08−31 1 2 : 00 : 0 0 0 2048 1361 : 21 0. 48 27 4. 41 31 5. 83 : SST

9 : 1987−09−30 1 2 : 00 : 0 0 0 2048 1361 : 21 0. 48 27 2. 37 31 2. 86 : SST

10 : 198 7−10−31 1 2 : 0 0 :0 0 0 2048 1361 : 219 .4 6 270 .5 3 309 .5 1 : SST

11 : 198 7−11−30 1 2 : 0 0 :0 0 0 2048 1361 : 230 .9 8 269 .8 5 308 .6 1 : SST

12 : 198 7−12−31 1 2 : 0 0 :0 0 0 2048 1361 : 241 .2 5 269 .9 4 309 .2 7 : SST

Reference manual Information

2.1.2. SINFO - Short information

Synopsis

<operator > ifiles

Description

This module writes information about the structure of ifiles to standard output. ifiles is an

unlimited number of input ﬁles. All input ﬁles need to have the same structure with the same

variables on diﬀerent timesteps. The information displayed depends on the chosen operator.

Operators

sinfo Short information listed by parameter identiﬁer

Prints short information of a dataset. The information is divided into 4 sections. Section

1 prints one line per parameter with the following information:

• institute and source

• timestep type

• number of levels and z-axis number

• horizontal grid size and number

• data type

• parameter identiﬁer

Section 2 and 3 gives a short overview of all grid and vertical coordinates. And the last

section contains short information of the time coordinate.

sinfon Short information listed by parameter name

The same as operator sinfo but using the name instead of the identiﬁer to label the

parameter.

Example

To print short information of a dataset use:

cdo sinfon ifile

This is the result of an ECHAM5 dataset with 3 parameter over 12 timesteps:

−1 : I n s t i t u t So urce Ttype L ev e ls Num G r id s i z e Num Dtype : Name

1 : MPIMET ECHAM5 co ns ta nt 1 1 2048 1 F32 : GEOSP

2 : MPIMET ECHAM5 i n s t a n t 4 2 2048 1 F32 : T

3 : MPIMET ECHAM5 i n s t a n t 1 1 2048 1 F32 : TSURF

Grid c o o r d i n a t e s :

1 : g a us si a n > s i z e : dim = 2048 nlon = 64 n l a t = 32

l o ng i t u d e : f i r s t = 0 l a s t = 3 54 .37 5 i nc = 5. 6 2 5

l a t i t u d e : f i r s t = 8 5.7 605 871 l a s t = −85.7605871

V e r t i c a l c o o r d i na t e s :

1 : s u r f a c e : 0

2 : p r es s u r e Pa : 92500 85000 50000 20000

Time co o rd i n at e : 12 s t e p s

YYYY−MM−DD hh :mm: s s YYYY−MM−DD hh :mm: s s YYYY−MM−DD hh :mm : s s YYYY−MM−DD hh :mm: s s

19 87−01−31 1 2 : 0 0 : 0 0 1987−02−28 1 2 : 0 0: 0 0 1987−03−31 1 2 : 0 0 : 0 0 1987−04−30 1 2 : 0 0 :0 0

19 87−05−31 1 2 : 0 0 : 0 0 1987−06−30 1 2 : 0 0: 0 0 1987−07−31 1 2 : 0 0 : 0 0 1987−08−31 1 2 : 0 0 :0 0

19 87−09−30 1 2 : 0 0 : 0 0 1987−10−31 1 2 : 0 0: 0 0 1987−11−30 1 2 : 0 0 : 0 0 1987−12−31 1 2 : 0 0 :0 0

Information Reference manual

2.1.3. DIFF - Compare two datasets ﬁeld by ﬁeld

Synopsis

<operator > ifile1 ifile2

Description

Compares the contents of two datasets ﬁeld by ﬁeld. The input datasets need to have the same

structure and its ﬁelds need to have the same header information and dimensions.

Operators

diﬀ Compare two datasets listed by parameter id

Provides statistics on diﬀerences between two datasets. For each pair of ﬁelds the operator

prints one line with the following information:

• Date and Time

• Level, Gridsize and number of Missing values

• Occurrence of coeﬃcient pairs with diﬀerent signs (S)

• Occurrence of zero values (Z)

• Maxima of absolute diﬀerence of coeﬃcient pairs

• Maxima of relative diﬀerence of non-zero coeﬃcient pairs with equal signs

• Parameter identiﬁer

Absdiff (t, x) = |i

(t, x) − i

(t, x)|

Reldiff(t, x) =

(t, x) − i

(t, x)|

max(|i

(t, x)|, |i

(t, x)|)

diﬀn Compare two datasets listed by parameter name

The same as operator diﬀ. Using the name instead of the identiﬁer to label the parameter.

Example

To print the diﬀerence for each ﬁeld of two datasets use:

cdo diffn ifile1 ifile2

This is an example result of two datasets with one 2D parameter over 12 timesteps:

Date Time L ev el S i z e Miss : S Z Max A b s diff M ax R el di ff : Name

1 : 1987−01−31 1 2 : 00 : 0 0 0 2048 1361 : F F 0. 000 106 81 4 .1 66 0 e −07 : SST

2 : 1987−02−28 1 2 : 00 : 0 0 0 2048 1361 : F F 6 .1 03 5 e−05 2 .3 742 e −07 : SST

3 : 1987−03−31 1 2 : 00 : 0 0 0 2048 1361 : F F 7 .6 29 4 e−05 3 .3 784 e −07 : SST

4 : 1987−04−30 1 2 : 00 : 0 0 0 2048 1361 : F F 7 .6 29 4 e−05 3 .5 117 e −07 : SST

5 : 1987−05−31 1 2 : 00 : 0 0 0 2048 1361 : F F 0. 000 106 81 4 .0 30 7 e −07 : SST

6 : 1987−06−30 1 2 : 00 : 0 0 0 2048 1361 : F F 0. 000 106 81 4 .2 67 0 e −07 : SST

7 : 1987−07−31 1 2 : 00 : 0 0 0 2048 1361 : F F 9 .1 55 3 e−05 3 .5 634 e −07 : SST

8 : 1987−08−31 1 2 : 00 : 0 0 0 2048 1361 : F F 7 .6 29 4 e−05 2 .8 849 e −07 : SST

9 : 1987−09−30 1 2 : 00 : 0 0 0 2048 1361 : F F 7 .6 29 4 e−05 3 .6 168 e −07 : SST

10 : 198 7−10−31 1 2 : 0 0 :0 0 0 2048 1361 : F F 9 .1 55 3 e −05 3 .5 001 e −07 : SST

11 : 198 7−11−30 1 2 : 0 0 :0 0 0 2048 1361 : F F 6 .1 03 5 e −05 2 .3 839 e −07 : SST

12 : 198 7−12−31 1 2 : 0 0 :0 0 0 2048 1361 : F F 9 .3 55 3 e −05 3 .7 624 e −07 : SST

剩余196页未读，继续阅读

sunshine986748197

粉丝: 0
资源: 1

气象CDO：数据处理与运算工具详解

cliamte data operators（cdo）指南

cdo-1.9.7.1-cygwin64-Win10.zip

CDO相关文档（climate data operators）

conda创建cdo环境

合并多个nc数据_气象数据处理的火箭加速器—CDO

cdo 处理wrf降水

vb cdo接收邮件

windowns10安装CDO

cdo如何计算日尺度数据的20年的滑动平均

Unable to locate package cdo

最新资源