The Northern North Pacific (NNP) is a resource-rich coastal zone with abundant fisheries and other
material resources. This climatology is based on more than seventy years of observations, and incorporates a significant amount of data not previously available to the public. The previous version (version 1) of this climatology was published over 10 years ago and was based on the 2013 edition of the World Ocean Database (WOD13).
Version 2 is based on WOD23, which includes a large volume of new data that enables a more detailed version of the NNP RC. This update will improve our understanding of the most recent ocean climate change in this region.
Access Methods
These decadal climatologies were generated from regional data extracted from the global World Ocean Database. Input datasets are described in the WOD23 documentation.
Citations
Version 2
Seidov, D., Mishonov, A.V., Baranova, O.K., Boyer, T.P., Nyadjro, E., Bouchard, C., Cross, S.L., 2023: Northern North Pacific Regional Climatology, v2. (NCEI Accession 0283566). NOAA National Centers for Environmental Information. Dataset doi:10.25921/dym6-q737
Version 1
Seidov, Dan; Baranova, Olga K.; Boyer, Tim P.; Mishonov, Alexey V.; Parsons, A. Rost (2016). Northern North Pacific Regional Climatology (NCEI Accession 0156768). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.7289/v5kk98tq. Accessed [date].
Parameters
A set of analyzed temperature and salinity fields was computed for the NNP domain to assess long-term climatological tendencies in this important region of the North Pacific Ocean. The set contains additional parameters that may be useful for applied climate studies, including:
- Simple statistical means
- Data distributions
- Standard deviations
- Standard errors of the mean
- Observed minus analyzed
- Seasonal/month minus annual mean
These parameters were computed using all data available in the World Ocean Database released in 2023 (WOD23).
Analysis Methods
Seasonal and annual fields are based on complete monthly analyses of all three horizontal grids (1°x1°, a 1/4°x1/4°, and 1/10° x 1/10°), which are computed by averaging seven decadal monthly analyses from 1955 to 2022. Seasonal fields at all depths above 1500 meters are computed from the average of the three months comprising each season (e.g., January, February, and March for winter), while annual mean fields are computed by averaging the four seasonal fields at all depths. The annual analysis of measurements below 1500 meters is the mean of the four seasonal analyses, and only shows annual and seasonal fields (the monthly fields below 1500 meters are not provided).
Using High Resolution Fields
High-resolution monthly temperature and salinity fields on the 1/10°x1/10° grid have more data gaps than seasonal and annual fields computed from the monthly fields. High-resolution analyzed fields, and particularly the high-resolution monthly fields, should be reviewed carefully before use in critical applications.
Please review the data distribution and statistical mean arrays before using high-resolution analyzed temperature and salinity fields or their climatological means. The monthly maps of objectively analyzed data on 1/10°x1/10° may show too strong eddy-like irregularities in some regions due to a combination of interpolation and plotting artifacts. These cases are rare, but need to be considered before using analyzed variables in research or applications.
Temperature and Salinity
Temperature and salinity climatologies are calculated separately because there is much more temperature data than salinity data. Because of this disparity, there are not always concurrent temperature and salinity measurements.
This discrepancy can create instabilities in the vertical density when density is calculated from standard level temperature and salinity climatologies. Appendices A and B in (Locarnini et al., 2023) describe a method for stabilizing the water column anywhere in the world ocean by minimally altering climatological temperature and salinity profiles. All analyses shown in the NNP regional climatology were stabilized using this method.
Other parameters from WOD23 that are included in the WOA23, such as oxygen, nutrients, etc., were not additionally processed in the NNP RC version 2. Those parameters are provided in WOA23 on the 1°x1° grid only and would not provide any additional value to the high-resolution temperature and salinity NNP RC. Therefore, they were not included. The one-degree resolution fields of all parameters other than temperature and salinity can be directly extracted from the WOA23.
Area
The NNP domain is encompassed between 155°E and 120.0°W longitudes and between 50.0°N and 69°N latitudes.
Temporal Resolution
All data from the WOD23 for the NNP domain were used to calculate seven decadal climatologies within the following time periods: 1955–1964; 1965–1974; 1975–1984; 1985–1994; 1995–2014; 2005–2014, and 2015–2022. The “all averaged decades” climatology was calculated by averaging six individual decades listed above (see World Ocean Database 2023 Introduction).
Each decadal climatology consists of:
Annual Fields
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Computed as 12-month averages
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Seasonal Fields
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Winter (Jan.-Mar.), Spring (Apr.-Jun.), Summer (Jul.-Sep.), Fall (Oct.-Dec.) computed as 3-month averages
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Monthly Fields
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Computed as 1-month averages
Spatial Resolution
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Annual and Seasonal Fields
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1°x1°, 1/4°x1/4°, and 1/10°x1/10° latitude/longitude grids
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Monthly Fields
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1°x1° and 1/4°x1/4° grids
Vertical Resolution
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Annual and Seasonal Fields
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Calculated from 0 to 5500 m depth on 102 standard levels
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Monthly Fields
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Calculated from 0 to 1500 m on 57 standard levels
Standard depth levels in the NNP regional climatology are the same as in the WOA23 (see Table 3 in the WOA23 documentation).
Objectives
Seasonal and annual fields are available on higher spatial resolutions (here the 1/10°x1/10° grid), which provides major advantages in areas with sufficient data availability. However, there is not enough data to fully support monthly fields at this resolution.
The quality control on a higher-resolution grid reveals more outliers than an analysis on coarser grids. More importantly, with the significantly shorter radius of influence in the objective analysis procedure, the structure of the gridded fields is far better sustained, especially in regions with sharp gradients of the essential oceanographic parameter (temperature and salinity).
Units
Temperature units are °C. Salinity is unitless on the Practical Salinity Scale-1978.
Bathymetry
For all three grid resolutions, mean depth values at the center of a grid square with the respective resolution were extracted from the ETOPO2 World Ocean bathymetry.
Method
The methods for calculating mean climatological fields are described in detail in the following publications: Temperature: Locarnini et al., 2023, Salinity: Reagan et al., 2023.
Additional details on high-resolution climatological calculations are found in Boyer et al., 2005.
A discussion of using this method in high-resolution regional climatologies can be found in Seidov et al., 2018 and 2019.The updated table provides radii of influence for the analysis procedure as follows:
| Pass | 1° radius of influence | 1/4° radius of influence | 1/10° radius of influence |
|---|---|---|---|
| 1 | 892 km | 321 km | 253 km |
| 2 | 669 km | 267 km | 198 km |
| 3 | 446 km | 214 km | 154 km |
Most of the procedures used for generating NCEI regional climatologies are similar to those used for WOA23, e.g., (Locarnini et al., 2023; Reagan et al., 2023).
Related Publications
- Boyer, T., S. Levitus, H. Garcia, R.A. Locarnini, C. Stephens, and J. Antonov (2005). Objective analyses of annual, seasonal, and monthly temperature and salinity for the world ocean on a 0.25 degree grid. International Journal of Climatology, 25(7), 931–945.
- Levitus, S., 1982: Climatological Atlas of the World Ocean. NOAA Professional Paper 13, 173 pp., U.S. Gov. Printing Office, Rockville, MD. ftp://ftp.library.noaa.gov/noaa_documents.lib/NOAA_professional_paper/NOAA_paper_13.pdf
- Locarnini, R.A., A.V. Mishonov, O.K. Baranova, J.R. Reagan, T.P. Boyer, D. Seidov, Z. Wang, H.E. Garcia, C. Bouchard, S.L. Cross, C.R. Paver, and D. Dukhovskoy (2023). World Ocean Atlas 2023, Volume 1: Temperature. A. Mishonov, Technical Editor. NOAA Atlas NESDIS 89, 42 pp. doi: 10.25923/54bh-1613.
- Seidov, Dan; Baranova, Olga K.; Biddle, Mathew; Boyer, Timothy P.; Johnson, Daphne R.; Mishonov, Alexey V.; Paver, Christopher; Zweng, Melissa (2013). Greenland-Iceland-Norwegian Seas Regional Climatology (NCEI Accession 0112824). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. doi: 10.7289/V5GT5K30.
- Seidov, D., A. Mishonov, J. Reagan, O. Baranova, S. Cross, and R. Parsons (2018). Regional Climatology of the Northwest Atlantic Ocean: High-Resolution Mapping of Ocean Structure and Change. Bulletin of the American Meteorological Society, 99(10), 2129-2138, doi:10.1175/BAMS-D-17-0205.1.
- Seidov, D., A. Mishonov, J. Reagan, and R. Parsons (2019). Eddy-Resolving In Situ Ocean Climatologies of Temperature and Salinity in the Northwest Atlantic Ocean. Journal of Geophysical Research: Oceans, 124(1), 41-58. doi:10.1029/2018JC014548.
- Reagan, J.R., D. Seidov, T.P. Boyer, R.A. Locarnini, H.E. Garcia, A.V. Mishonov, O.K. Baranova, C.R. Paver (2023). World Ocean Atlas 2023, Volume 2: Salinity. A. Mishonov, Technical Editor, NOAA Atlas NESDIS 90, 50pp. doi:10.25923/70qt-9574.
