详细信息
id
1
标题
逐月北极海冰覆盖及南极冰盖资料(1901-1995)
描述

南北极逐月冰覆盖资料(1901-1995)


资料集名称: 南北极逐月冰覆盖资料
责任者: NCAR
资料集编号: DS007-1
索取号: T8004-8
索引名: ice
记录年代: 北极地区 1901年1月—1995年8月
南极地区 1973年1月—1990年12月
区域: 北极南极地区
要素: 格点浓度
编排: 网格点
统计特征:
详介: 网格:格点数目
北极地区80×58,
南极地区80×80,
观测次数、时间:
站数/层数、层次:
载体说明:
数量: 13MB
缺测:
数据来源: NCAR DS233.0
质量检验:
备注:
并列分类码:
参考文献: 见附录
调用程序:CALL ice(AA,IY,IM,IT, Xlon, Ylat, IG, *)
参数意义:AA 整型数组80×58或80×80,程序返回时为所调资料
IY 整型量,年
IM 整型量,月
IT 整型量 南北标识
北极 = 1
南极 = 2
Xlon 实型数组 格点纬度 数组长度同AA
Ylat 实型数组 格点经度 数组长度同AA
IG 整型数组 陆海标识 数组长度同AA
* 语句标号,所调资料没找到时,按此标号返回
编译时需连接库 -ldatabank

附 录:
**********************************************************************************

/DSS/D/DS233.0 WALSH'S ARCTIC AND ANTARCTIC SEA ICE CONCENTRATION ANALYSES Steve Worley
*** Mon Oct 7 14:52:09 MDT 1996
*** worley@ncar.ucar.edu
*** (303)-497-1248
***
***
*** Prepared and maintained by the Data Support Section, Scientific
*** Computing Division, National Center for Atmospheric Research. NCAR
*** is operated by the University Corporation for Atmospheric Research and
*** is sponsored by the National Science Foundation. Please credit when
*** publishing research which utilized data from this archive. The original
*** source of the data should also be acknowledged.
***
*** Direct inquiries to the person shown above, to the person[s] whose
*** last name[s] appears on the 'specialist:' line below, or to Roy Jenne,
*** the manager of the Data Support Section. A file of staff phone numbers
*** and E-mail addresses may be found under the home directory in the file
*** named staff.
***
*** First time users of our archive, or this data set, should contact
*** the specialist[s] before attempting to access the data. We can provide
*** users with access routines, format documentation [mentioned on the
*** 'format refs:' line in the listing below], and advice.
***

*** Experienced users of this data set should from time to time make a

*** new listing of this file, as we update our tapes and documentation

*** without notice.

***

****************************************************************************

***

DATA SET: 233.0

TITLE: WALSH'S ARCTIC AND ANTARCTIC SEA ICE CONCENTRATION ANALYSES

SUMMARY: USING VARIOUS SOURCES FOR SEA ICE CONCENTRATION JOHN WALSH

SUMMARY: AND BILL CHAPMAN HAVE DERIVED A MONTHLY TIME SERIES OF

SUMMARY: ARCTIC AND ANTARCTIC SEA ICE CONCENTRATION.

VOLUME: 14 MB

DAN SECTIONS: R

TN REFERENCES:

FORMAT REFS: ANONYMOUS FTP MACHINE: NCARDATA.UCAR.EDU

FORMAT REFS: IN DIRECTORY: ~FTP/DATASETS/DS233.0

FORMAT REFS: SEE FILE: README

TYPES: GRIDDED TIMESER SEANAL OCEAN

GRIDS: ARCTIC POLAR 80X58 AREA

GRIDS: ANTARCTIC POLAR 80X80 AREA

LEVELS: SFC

VARIABLES: ICE

PERIODS: 1901JAN-1990

PERIODS: 1973JAN-1990

TIMES: MOLY AT END OF MONTH

STATISTICS:

SOURCES: WALSH UNIV IL NISDC CHAPMAN UNIV IL.

SPECIALIST: WORLEY STERN SPANGLER

PUBLICATIONS: THE INCORPORATION OF ICE STATION DATA INTO A STUDY OF RECENT

PUBLICATIONS: ARCTIC TEMPERATURE FLUCTUATIONS, JOHN E. WALSH, MWR, DEC77

PUBLICATIONS:

PUBLICATIONS: RECENT VARIATIONS OF SEA ICE AND AIR TEMPERATURE IN HIGH

PUBLICATIONS: LATITUDES, WILLIAM CHAPMAN AND JOHN WALSH, BULL. AMS, VOL. 74,

PUBLICATIONS: NO. 1, JANUARY 1993

 

 

FILES (ON THE MSS) -

FILENAME (SPECIFY IN UPPER CASE) DESCRIPTION

VSN -FF T,DD PERIOD AND COMMENTS

-

- NATIONAL SNOW AND ICE DATA CENTER (NISDC) VERSION

- COLLECTED VIA FTP, SEPTEMBER 1996

Y32884 ARCTIC_ANTARCTIC_SEA.ICE.TAR, UNIX TAR FILE CONTAINING

- THE FOLLOW DATA, DOCUMENTATION, AND ACCESS PROGRAM FILES

-

- =================================================================

- ARCTIC DATA

- ------------

- ARCTIC_CON_01-90.DOC_NCAR ------- DOCUMENTATION

- ARCTIC-CONCENTRATION-01-90.DAT ------- SEA ICE CONCENTRATION 1901-1990

- ARCTIC-CONCENTRATION-01-90.SOURCE------- ORIGINAL DATA SOURCE FLAG GRID

- ARCTIC.GRID ------- GEOGRAPHICAL ICE AREA SIZE GRID

- ARCTIC.LATLON ------- LATITUDE/LONGITUDE COORDINATE GRID

-

- ARCTIC ACCESS PROGRAMS

- ---------------------

- R_ARCTIC_ANC.F ------- READS 3 ANCILLARY GRID FILES,

- A) LATITUDE/LONGITUDE COORD. GRID

- B) ICE AREA GRID

- C) DATA SOURCE FLAG GRID

- R_ARCTIC_CON.F ------- READ GRID COORDINATES AND SEA ICE

- CONCENTRATION

- ARCTIC_SAMPLE.OUT ------- SAMPLE OUTPUT FROM R_ARCTIC_CON.F

- ARCTIC_SAMPLE.OUT1 ------- SAMPLE OUTPUT FROM R_ARCTIC_ANC.F

-

- ===============================================

-

- SOUTHERN OCEAN (ANTARCTIC) DATA

- -------------------------------

- SOUTHERN_CON_73-90.DOC_NCAR ------- DOCUMENTATION

- SOUTHERN-73-90.DAT ------- SEA ICE CONCENTRATION 1973-1990

- SOUTHERN.LATLON ------- LATITUDE/LONGITUDE COORDINATE GRID

-

- SOUTHERN OCEAN ACCESS PROGRAMS

- ------------------------------

- R_SOUTHERN_CON.F ------- READ GRID COORDINATES AND SEA ICE

- CONCENTRATION

- SOUTHERN_SAMPLE.OUT ------- SAMPLE OUTPUT FROM R_SOUTHERN_CON.F

-

- ========================================================

-

- FILES FROM THE NATIONAL SNOW AND ICE DATA CENTER (NISDC)

- [NOT RECOMMENDED OR REQUIRED]

-

- INDEX

- ARCTIC-CONCENTRATION-01-90.DOC

- RCTIC-CONCENTRATION-01-90.TEMPLATE

- SOUTHERN-73-90.DOC

- SOUTHERN.TEMPLATE

 

 

 

 

 

 

 

Monthly Arctic Sea Ice Concentration Grids

(January 1901 - December 1990)

 

 

I. DATA DOCUMENTATION

File 1: Arctic Sea Ice Concentrations

This file contains rectangular, equal area grids of monthly

sea ice concentrations. The grids depict ice

conditions at the END of each of 1080 months (1901-1990 inclusive).

The monthly values are interpolated to the last day of each month,

rather than being values for the last week of each month. [Note that this

dataset differs from most other climatological datasets which contain

monthly AVERAGES, not end of the month values.]

Ice concentration values are ASCII characters representing the number

of tenths of ice coverage in each grid area. The 80x58 rectangular

grid overlays the North Pole with equal area projection. Each grid box

covers 60 square nautical miles (equivalent to 1 degree latitude

square). The latitude and longitude coordinates for each grid point

are defined by data in File 2 (see below).

The following formatted FORTRAN READ statement will place an 80 x

58 ice concentration grid into the array ACON(80,58).

READ(NU,1000) MONTH, YEAR

DO 10 J=1,58

READ(NU,1010) (ACON(i,j),i=1,80)

10 CONTINUE

1000 FORMAT(I5,I5)

1010 FORMAT (80A1)

 

 

where month = (1,2,...,12) and

year = (1901,1902,...,1990)

The file contains 1080 grids, arranged sequentially as follows:

1) January 1901

2) February 1901

. .

. .

. .

. .

1079) November 1990

1080) December 1990

Possible "character" grid point values for the ice concentration grids are:

'0','1',...,'9' tenths of grid square area covered by ice.

'*' ten/tenths sea ice coverage

'.' grid point lies over land.

 

*********************************************************************************

File 2: Latitude/Longitude Coordinates for Arctic Grids.

This file contains the latitude (degrees N) and longitude (degrees E)

coordinates for all points in the 80 x 58 Arctic grid.

The positive x axis is along 340E, the positive y axis is along 70E,

and these axes intersect at point (35,24) which is the North Pole. The

(1,1) grid point is considered to be the upper left hand corner of the

grid rectangle. Some reference grid points are:

latitude and longitude grid coordinate samples:

( 1, 1) = 48.9512 N 125.923 E

( 1, 2) = 49.5031 N 127.095 E

(35,24) = 90.0000 N 250.000 E

( 1,58) = 41.9167 N 205.000 E

(80, 1) = 39.4629 N 7.07210 E

(80,58) = 33.5996 N 302.927 E

The following FORTRAN READ statement will put the latitudes and

longitudes into REAL arrays xlat(80,58) and xlon(80,58):

 

READ (NU,1000) ((xlat(i,j),i=1,80),j=1,58)

READ (NU,1000) ((xlon(i,j),i=1,80),j=1,58)

1000 FORMAT(80(f8.4,1x))

 

**********************************************************************************

File 3: Arctic Sea Ice Area Grid

The following formatted FORTRAN READ statement will place an 80 x

58 ice concentration grid into the array IAREA(58,80).

DO 10 J=1,58

READ(NU,1010) (IAREA(i,j),i=1,80)

10 CONTINUE

1000 FORMAT(I5,I5)

1010 FORMAT (80(I2,1x))

The "Area grid" contains the ocean areas corresponding to each

grid point. Possible area grid point values are:

1,2,...,19,20 Number of tenths of 1 degree latitude square

covered by ocean (e.g., 10 = 60x60 n mi2); values

exceeding 10 are found near land areas where

adjacent grid point(s) lie over land.

0 Point lies over ocean but not within ice grid area

of Figure 1. [Walsh's figure supplied in hard copy

only].

-1 Grid point lies over land.

See the supplementary Documentation Section at the end of this document

for further description of the ice area grid.

**********************************************************************************

File 4: Data source grids

 

The data sources for the ice concentrations vary spatially and temporally.

There are six basic data sources for the ice concentrations:

1. Danish Meteorlogical Institute

2. Japan Meteorological Agency

3. Naval Oceanographic Office (NAVOCEANO)

4. Kelly ice extent grids

5. Walsh and Johnson/Navy-NOAA Joint Ice Center

6. Navy-NOAA Joint Ice Center Climatology

7. ** Temporal extension of Kelly grids (see note below)

Each ocean grid point will be assigned a value (1-7) indicating the source

of the data for each corresponding ice concentration grid. There is a data source grid for each monthly sea-ice concentration grid 1901-1990.

The following formatted FORTRAN READ statement will place an 80 x

58 ice source grid into the array ACON(80,58).

READ(NU,1000) MONTH, YEAR

DO 10 J=1,58

READ(NU,1010) (ACON(i,j),i=1,80)

10 CONTINUE

1000 FORMAT(I5,I5)

1010 FORMAT (80A1)

 

where month = (1,2,...,12) and

year = (1901,1902,...,1990)

** TEMPORAL EXTENSION OF KELLY GRIDS:

Sea ice extent data is provided by Kelly, et. al. 1988. The ice extent

data is compiled for the months April-August for the majority of the period

1901-1956. In this dataset, we utilize the Kelly data to create an ice

concentration data source for the early period of record. This data is

given very low priority in the hierarchy of available data so that if there are

data from any sources (except climatology), we replace the extended

Kelly data with this new source data. The modification of the Kelly data

is done in two parts: (1) conversion from ice extent to ice concentrations, and

(2) temporal extension of the available data.

(1) We add a marginal sea ice zone to the Kelly ice extent data by computing

average ice concentration drop-off rates for the "satellite period". These

drop-off rates indicate the rate at which ice concentrations decrease as

a function of distance from open water and distance from 10/10 ice

concentrations. The drop off rates vary with season; the summer melt season

drop-off rate is about 0.5 that of the freeze-up season. We apply

these drop-off rates to the Kelly ice extent data to create a "realistic"

marginal sea ice zone.

(2) Regional sea ice anomalies have been shown to persist for many months and

even seasons (Chapman and Walsh, 1991). We attempt to capitalize on this

persistence by extending the ice anomaly data from (1) forward and

backward in time to fill in the months September-March for each year in the

1901-1956 period. We compute lagged autocorrelations for the "satellite period"

and use the autocorrelations as weighting functions in the temporally extended

data. For example, an anomaly for November is made by summing the anomalies

of the preceeding August and the subsequent April weighted by the -3 month lag

autocorrelation and the +5 month lag autocorrelations, respectively.

We have attempted to stretch the useful information included in the Kelly

ice extent data to extract as much information as possible from the data.

We feel that the addition of these extensions make a more complete and

detailed dataset useful for most applications. If however, you prefer a

version of the dataset which omitts the extended Kelly data in favor of

the JIC climatology, we will be happy to accommodate you.

*****************************************************************************

II. SUPPLEMENTARY DOCUMENTATION

 

Grid Cell Value Coding Scheme

W. Chapman (Univ. Illinois) and C. Hanson (NSIDC)

92/04/13

Grid cell values:

The "area grid" assigns values to grid cells based on whether they

represent land or ocean areas. Grid cells are defined by the

center point of the cell. If the center point lies over land the

cell value is -1 in the area grid and in the ice concentration

grids. The ocean area of the cell is "given" to an adjacent cell.

A grid cell has a value of -1 in the Arctic if the cell lies

entirely over land.

A grid cell has a value of 0 if the cell lies over ocean but

is outside the ice grid depicted in Figure 1. [Walsh's figure,

supplied in hard copy only.]

A grid cell has a value of 10 if the cell lies entirely over

ocean.

A grid cell partly over land and partly over ocean has a value

of -1, if the center point of the cell is over land. The cell

adjacent (oceanwards) has a value of 10 plus its neighbor's

ocean area value. See Figure 2 [contained in this file]. A

grid cell partly over land and partly over ocean with its

center point over ocean is given the value (in tenths) of the

area of the grid cell covered by ocean. (i.e. a number

between 0 and 10).

 

Figure 2:

-------------------- Shown are three adjacent grid cells,

| | | | with the center point of each indicated

| . | . | . | by the dots. The slashes through cell

| / | | | are intended to indicate a continental

----/----------------- outline extending into cell 1. Land is

cell 1 cell 2 cell 3 to the left of the line, ocean is to the

right. The cells in Figure 2 would be

coded as follows in the "area grid":

Cell 1 = -1 (land)

Cell 2 = 16 (cell 2 is entirely ocean so value is 10, cell 1

is 6 tenths ocean so value is 6; 6 + 10 = 16)

Cell 3 = 10 (ocean)

This coding scheme excludes "land" cells from calculations of ice

coverage, without excluding the area of ocean within a "land" cell

that contains part land and part ocean.

The following explanation was contributed by John Weatherly, University

of Illinois, Department of Atmospheric Sciences:

Given an Arctic grid point at : A degrees E longitude

B degrees N latitude

In the Arctic grid, this point is at:

YJ = 24 + (90 - B) cos(2(3.14)*(A+110)/360)

XI = 35 + (90 - B) sin(2(3.14)*(A+110)/360)

70 E

YJ

(1,1) _____________________|____________________(1,80)

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| NP |____________________|____ XI

| (35,24) | 340 E

| |

| |

| |

| |

| |

| |

|_________________________________________|

(58,1) (58,80)

 

*******************************************************************************

Monthly Sea Ice Concentration Grids: References

Chapman, W.L. and J.E. Walsh (1991) Long-Range Prediction of Regional

Sea Ice Anomalies in the Arctic. "Weather and Forecasting", 6(2), pp.

271-288.

Walsh, J.E. (1978) A data set on Northern Hemisphere sea ice

extent. World Data Center-A for Glaciology (Snow and Ice),

"Glaciological Data, Report GD-2", part 1, pp. 49 - 51.

Walsh, J.E. and C.M. Johnson (1978) Analysis of Arctic sea ice

fluctuations 1953-77. "Journal of Physical Oceanography", 9(3), p.

580-591.

Technical Report of the Japan Meteorological Agency (JMA) No. 109 (ISSN 0447-3868)

titled "Report on 30 years of Observation of Sea Ice" by Marine Department, JMA.

Published by JMA, Tokyo, February 1988.

Kelly, P.M. An Arctic Sea Ice Data Set, 1901-1956. Climate Research Unit,

University of East Anglia.

Contacts for questions:

NSIDC User Services

CIRES/Campus Box 449

Boulder, CO 80309-0449

Phone: 303-492-6199

Fax: 303-492-2468

Email: nsidc@kryos.colorado.edu

Bill Chapman

University of Illinois

Dept. of Atmospheric Sciences

105 S. Gregory Ave.

Urbana, IL 61801

217-333-6881

Email: chapman@faldo.atmos.uiuc.edu

 

 

 

 

 

 

 

 

 

 

 

Monthly Sea Ice Concentration Grids

Southern Ocean(January 1973 - December 1990)

 

I. DATA DOCUMENTATION

Southern Ocean Sea Ice Concentration Grids.

The Antarctic region sea ice concentrations for the years 1973 - 1990

inclusive are stored on rectangular equal-area grids. There are 216 ice

concentration grids. The grids depict the ice concentrations at the end of

each labelled month. The grid interval is 1 degree latitude (60 n mi); the

grid size is 80 x 80 points, with the south pole at (40,40). The point (1,1)

is located at 225 degrees E, 34 degrees S, and the positive x- and y- axes are

at 0 degrees E and 90 degrees E, respectively.

The following FORTRAN read statment will place an 80 x80 ice concentration

grid into the array iant (80,80):

 

read(NU,1000) year, month

read (NU,1010) ((iant(i,j),i=1,80),j=1,80)

1000 format(I5,I5)

1010 format(80(I2,1x))

 

Possible grid point values for the 216 ice concentration grids are:

0,1,...,9,10 Tenths of grid square area covered by ice.

99 Grid point lies over land. Note that some land grid values don't

correspond to the Antarctic coastline due to digitizing errors.

Latitude/Longitude Coordinates for Antarctic Grids.

This file contains the latitude (degrees S) and longitude (degrees E)

coordinates for all points in the 80 x 80 Antarctic grid.

The following FORTRAN READ statement will put the latitudes and longitudes

into REAL arrays xlat(80,80) and xlon(80,80):

read (NU,101) ((xlat(i,j),j=1,80),i=1,80)

read (NU,101) ((xlon(i,j),j=1,80),i=1,80)

101 format(80(F8.4,1x))

latitude and longitude grid coordinate samples:

( 1, 1) = 34.8457 225.000

( 1,40) = 51.0000 180.000

(40,40) = 90.0000 270.000

(40,80) = 50.0000 90.0000

( 1,80) = 34.1341 134.275

(80, 1) = 34.1341 315.725

(40, 1) = 51.0000 270.000

(80,80) = 33.4315 45.0000

(80,40) = 50.0000 0.

 

II. SUPPLEMENTARY DOCUMENTATION

 

Given an Antarctic grid point at : A degrees E longitude

B degrees N latitude (i.e. negative S lat.)

 

In the Antarctic grid , this point is at:

YJ = 40 + (90 + B) cos(2(3.14)*(90-A)/360)

XI = 40 + (90 + B) sin(2(3.14)*(90-A)/360)

270 E

YJ

(1,1) _____________________|____________________(80,1)

| | |

| | |

| | |

| | |

| | |

| | |

| | |

180E|________________ SP |____________________|____ XI

(1,40)| (40,40) | 0 E

| | |(80,40)

| | |

| | |

| | |

| | |

| | |

|____________________|____________________|

(1,80) 90E (40,80) (80,80)

References:

Walsh, J.E. (1978) A data set on Northern Hemisphere sea ice

extent. World Data Center-A for Glaciology (Snow and Ice),

"Glaciological Data, Report GD-2", part 1, pp. 49 - 51.

Walsh, J.E. and C.M. Johnson (1978) Analysis of Arctic sea ice

fluctuations 1953-77. "Journal of Physical Oceanography", 9(3), p.

580-591.

Questions:

User Services

National Snow & Ice Data Center

CIRES/Campus Box 449

Boulder, CO 80309-0449

 

Phone: 303-492-6199

Fax: 303-492-2468

Email: nsidc@kryos.colorado.edu

Bill Chapman

University of Illinois

Dept. of Atmospheric Sciences

105 S. Gregory Ave.

Urbana, IL 61801