Skip to contents

fao_area_sst(): FAO主要渔区的海表温度

Source: vignettes/articles/zh/reference/fao_area_sst.Rmd
fao_area_sst.Rmd

英文原页：fao_area_sst()

说明

本函数返回19个FAO主要海洋渔区的逐年海表温度（SST）：渔区平均值、渔区内的范围和季节范围，每个渔区每年一行，与FAO捕捞统计的形式相同。mean_temperature_catch()会用到本函数。它总会说明所用的是哪一套SST数据。

English

This function returns the yearly sea surface temperature (SST) of the 19 FAO major marine fishing areas: the area mean, the range within the area and the seasonal range, one row per area and year, like the FAO catch statistics. It is used by mean_temperature_catch(). It always says which SST data it uses.

用法 

fao_area_sst(
  area = NULL,
  sst = fao_setting("sst"),
  level = c("area", "division"),
  variable = NULL,
  data_dir = fao_data_dir()
)

参数

area
FAO渔区代码（例如”34”），或FAO数据中的渔区名称（例如”Atlantic, Eastern Central”）。默认为NULL，即全部渔区。
English FAO area codes (e.g. “34”) or names as in the FAO data (e.g. “Atlantic, Eastern Central”). Default is NULL, all areas.
sst
SST数据：“ersst5”（包内自带）、用download_sst_data()下载的产品名称，或者一个NetCDF文件的路径或存放NetCDF文件的文件夹路径。默认为fao_settings()中的sst设置，未更改时为”ersst5”。
English The SST data: “ersst5” (built in), the name of a product downloaded with download_sst_data(), or the path of a NetCDF file or of a folder of NetCDF files. Default is the sst setting of fao_settings(), “ersst5” unless changed.
level
“area”（默认）表示19个FAO主要海洋渔区，“division”表示FAO亚区和分区（例如”37.1.1”，巴利阿里），与load_fao_divisions()的渔获数据一致（见“亚区和分区”一节）。
English “area” (default) for the 19 FAO major marine areas, or “division” for the FAO subareas and divisions (e.g. “37.1.1”, Balearic), as in the catch data of load_fao_divisions() (see Subareas and divisions).
variable
你的NetCDF文件中SST变量的名称。默认为NULL，即按变量名自动识别。
English The name of the SST variable in your NetCDF files. Default is NULL, found from its name.
data_dir
保存下载数据和计算结果表的目录。默认为fao_data_dir()。
English The directory where downloaded data and computed tables are stored. Default is fao_data_dir().

返回值

一个数据框，每个渔区每年一行：product、area_code、area_en、year、sst_mean、sst_p10、sst_p90、sst_min_month、sst_max_month（单位均为°C）、n_cells（渔区内的网格数）、source（所用的SST数据）和downloaded（数据的下载或计算日期）。

English

A data frame with one row per area and year: product, area_code, area_en, year, sst_mean, sst_p10, sst_p90, sst_min_month, sst_max_month (all in °C), n_cells (grid cells in the area), source (the SST data used) and downloaded (date the data were downloaded or computed).

使用哪一套SST数据

  • 包内自带（默认）：NOAA ERSST v5：本包自带19个渔区1950年以来的逐年SST，由NOAA Extended Reconstructed SST version 5（Huang等，2017）计算得到。这是一套2° x 2°网格（约220 km）的逐月重建数据，仅使用现场观测（ICOADS的船舶和浮标资料，1999年起加入Argo浮标）。它是常用SST产品中最小的，无需下载，整个时段前后一致；但对于地中海和黑海这样的小渔区，它的网格偏粗（n_cells给出每个渔区的网格数）。
  • 你自己的NetCDF文件：把一个NetCDF文件的路径，或存放NetCDF文件的文件夹路径，作为sst给出，或者用fao_settings(sst = "path")为本次R会话统一设置。文件中必须有带经度、纬度和时间维度的网格化SST，逐月或逐日均可（例如HadISST、COBE-SST2、OISST、ERSST，或模式输出）。渔区逐年平均值在第一次使用时计算（可能需要几分钟），并保存在data_dir的sst文件夹中；之后用同样的文件调用时，直接读取保存的结果表。读取NetCDF文件需要ncdf4包。
  • 用download_sst_data()下载：download_sst_data()下载fao_sst_products()所列的一种产品（HadISST1、COBE-SST2、OISST v2.1，或ERSST v5的最新年份），并计算其数据表；之后按名称使用，例如sst = "hadisst1"。
English
  • Built in (default): NOAA ERSST v5: The package comes with the yearly SST of the 19 areas from 1950, computed from NOAA Extended Reconstructed SST version 5 (Huang et al. 2017): a monthly reconstruction on a 2° x 2° grid (about 220 km) from in situ observations only (ships and buoys of ICOADS, Argo floats from 1999). It is the smallest of the common SST products, needs no download, and is consistent over the whole period; its grid is coarse for small areas such as the Mediterranean and Black Sea (n_cells gives the number of grid cells of each area).
  • Your own NetCDF files: Give the path of a NetCDF file, or of a folder of NetCDF files, as sst, or once for the session with fao_settings(sst = "path"). The files must hold a gridded SST with longitude, latitude and time, monthly or daily (e.g. HadISST, COBE-SST2, OISST, ERSST, or a model output). The yearly area means are computed the first time, which can take a few minutes, and saved in the sst folder of data_dir; later calls with the same files read the saved table. Reading NetCDF files needs the ncdf4 package.
  • Downloaded with download_sst_data(): download_sst_data() downloads one of the products listed by fao_sst_products() (HadISST1, COBE-SST2, OISST v2.1, or the newest years of ERSST v5) and computes its table; it is then used by its name, e.g. sst = "hadisst1".

亚区和分区

level = "division"时，表中每个FAO亚区和分区（以本包所带的FAO地图inst/extdata/FAO_AREAS_CWP.shp为准）每年一行：area_code是其代码（例如”34.1.1”，或亚区”34.2”），area_en是其名称。内置的ERSST v5表包含34、37、47和51区的亚区和分区，即按分区的渔获数据（load_fao_divisions()）所涉及的渔区；由下载的产品或你自己的文件计算的表包含全部亚区和分区。很多分区对于2°网格来说太小（见n_cells；例如亚速海和马尔马拉海没有或只有几个网格），所以分区更适合使用分辨率更高的SST产品（给出其NetCDF文件的路径）。

English

With level = "division", the table has one row per FAO subarea and division of the FAO map in the package (inst/extdata/FAO_AREAS_CWP.shp): area_code is its code (e.g. “34.1.1” or the subarea “34.2”) and area_en its name. The built-in ERSST v5 table covers the subareas and divisions of areas 34, 37, 47 and 51, those of the catch data by division (load_fao_divisions()); tables from downloaded products or your own files cover all of them. Many divisions are small for a 2° grid (see n_cells; e.g. the Sea of Azov or the Sea of Marmara have none or a few cells), so a finer SST product, given as the path of its NetCDF files, suits divisions better.

渔区平均值的计算方法

  • 文件：SST变量按名称识别（“sst”、“analysed_sst”、“tos”等），除非用variable指定；经度可以是-180到180，也可以是0到360；以开尔文为单位的值换算成°C；有多个深度层时，使用第一层（表层）。低于-5 °C的值（有些产品用这种值标记海冰，HadISST1用-1000）设为-1.8 °C，即其他产品在海冰下给出的值。逐日数据先按月平均。
  • 细于1°的网格先平均到约1°（取有值网格的平均）。
  • 每个网格计入它所重叠的每个FAO主要渔区（inst/extdata/FAO_AREAS_CWP.shp，19个海洋渔区），权重为在球面上计算的重叠面积，因此位于边界上的网格由相邻渔区共享，沿岸网格只计算其海洋部分。
  • sst_mean是12个月渔区平均值的平均；sst_p10和sst_p90是各网格年平均SST的加权第10和第90百分位数（渔区内的范围）；sst_min_month和sst_max_month是最冷月和最暖月的渔区平均值（季节范围；在横跨赤道的渔区，南北两个半球的季节会部分抵消，所以这个范围较窄）。只保留12个月齐全的年份。

北冰洋渔区和南极各渔区的数值，有一部分反映的是海冰，而不是实测的水温。不同的SST产品使用不同的观测和方法，所以它们的数值和趋势会有一定差异；换用另一种产品重复分析，可以看出结果在多大程度上依赖所选的产品。

English
  • Files: the SST variable is found by its name (“sst”, “analysed_sst”, “tos”, …) unless given as variable; longitudes may run from -180 to 180 or from 0 to 360; values in kelvin are converted to °C; if there are several depths, the first (the surface) is used. Values below -5 °C, which some products use to mark sea ice (-1000 in HadISST1), are set to -1.8 °C, the value other products give under sea ice. Daily values are averaged by month.
  • Grids finer than 1° are first averaged to about 1° (mean of the cells with a value).
  • Each grid cell counts for each FAO major area it overlaps (inst/extdata/FAO_AREAS_CWP.shp, the 19 marine areas), weighted by the area of the overlap computed on the sphere, so cells on a boundary are shared and coastal cells count for their sea part only.
  • sst_mean is the mean of the 12 monthly area means; sst_p10 and sst_p90 are the weighted 10th and 90th percentiles of the yearly mean SST of the cells (the range within the area); sst_min_month and sst_max_month are the coldest and warmest monthly area means (the seasonal range; in areas on both sides of the equator the seasons of the two hemispheres partly cancel, so this range is narrow there). Only years with all 12 months are kept.

Values over the Arctic Sea and the Antarctic areas partly reflect sea ice rather than measured water temperature. SST products use different observations and methods, so their values and trends differ somewhat; repeating an analysis with a second product shows how much a result depends on the product.

参考文献

Hirahara, S., Ishii, M. and Fukuda, Y. (2014). Centennial-scale sea surface temperature analysis and its uncertainty. Journal of Climate 27: 57-75. doi:10.1175/JCLI-D-12-00837.1

Huang, B., Thorne, P.W., Banzon, V.F., Boyer, T., Chepurin, G., Lawrimore, J.H., Menne, M.J., Smith, T.M., Vose, R.S. and Zhang, H.-M. (2017). Extended Reconstructed Sea Surface Temperature, Version 5 (ERSSTv5): Upgrades, Validations, and Intercomparisons. Journal of Climate 30: 8179-8205. doi:10.1175/JCLI-D-16-0836.1

Huang, B., Liu, C., Banzon, V., Freeman, E., Graham, G., Hankins, B., Smith, T. and Zhang, H.-M. (2021). Improvements of the Daily Optimum Interpolation Sea Surface Temperature (DOISST) Version 2.1. Journal of Climate 34: 2923-2939. doi:10.1175/JCLI-D-20-0166.1

Rayner, N.A., Parker, D.E., Horton, E.B., Folland, C.K., Alexander, L.V., Rowell, D.P., Kent, E.C. and Kaplan, A. (2003). Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century. Journal of Geophysical Research 108 (D14): 4407. doi:10.1029/2002JD002670

HadISST1 dataset description, with the warning of 10 March 2016 and a link to the analysis by D. Chelton and C. Risien (https://ir.library.oregonstate.edu/xmlui/handle/1957/58385): https://coastwatch.pfeg.noaa.gov/erddap/info/erdHadISST/index.html

Web pages of the products: ERSST v5 https://www.ncei.noaa.gov/products/extended-reconstructed-sst; HadISST1 https://www.metoffice.gov.uk/hadobs/hadisst/; COBE-SST2 https://psl.noaa.gov/data/gridded/data.cobe2.html; OISST v2.1 https://www.ncei.noaa.gov/products/optimum-interpolation-sst

示例 

sst34 <- fao_area_sst("34")                          # built in: NOAA ERSST v5
plot(sst_mean ~ year, data = sst34, type = "l", ylim = range(sst34$sst_p10, sst34$sst_p90))
lines(sst_p10 ~ year, data = sst34, lty = 2)
lines(sst_p90 ~ year, data = sst34, lty = 2)

# Your own NetCDF file (e.g. HadISST_sst.nc downloaded from the Met Office), for one call ...
fao_area_sst("34", sst = "D:/data/HadISST_sst.nc")
# ... or for the whole session, including mean_temperature_catch()
fao_settings(sst = "D:/data/HadISST_sst.nc")

# Subareas and divisions, e.g. those of the Mediterranean and Black Sea
div <- fao_area_sst(level = "division")
subset(div, startsWith(area_code, "37.") & year == 2024)