PFEL Coastal Upwelling Indices

Available as - [Outline] - [SGML]

Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: Pacific Fisheries Environmental Laboratory (PFEL)
Publication_Date: On-line
Title: PFEL Coastal Upwelling Indices
Geospatial_Data_Presentation_Form:
Tables; Graphs Delivery Format: On-line; Six-Hourly Data
Online_Linkage:
<http://www.pfeg.noaa.gov/data_gate/pfeg_data_gate.html> <http://www.pfeg.noaa.gov/products/upwell.html> PFEL Live Access Server: <http://www.pfeg.noaa.gov/data_for_users/las.html>
Description:
Abstract:
"On a monthly basis, the Pacific Fisheries Environmental Laboratory generates indices of the intensity of large-scale, wind-induced coastal upwelling at 15 standard locations along the west coast of North America. The indices are based on estimates of offshore Ekman transport driven by geostrophic wind stress. Geostrophic winds are derived from six-hourly synoptic and monthly mean surface atmospheric pressure fields. The pressure fields are provided by the U.S. Navy Fleet Numerical Meteorological and Oceanographic Center (FNMOC), Monterey, CA. The idea behind the upwelling indices was to develop simple time series that represent variations in coastal upwelling. Daily and monthly index time series are provided regularly to scientists and managers concerned with marine ecosystems and their biota, and have been used in scores of studies and scientific publications." --Excerpted from PFEL Coastal Upwellling web site.

COASTAL UPWELLING INDEX STANDARD LOCATIONS ALONG WEST COAST OF NORTH AMERICA:

60N, 149W 60N, 146W 57N, 137W 54N, 134W 51N, 131W 48N, 125W 45N, 125W 42N, 125W 39N, 125W 36N, 122W 30N, 119W 27N, 116W 24N, 113W 21N, 107W

NOTE: All data available here can be plotted using the PFEL on-line Live Access Server, available at: <http://www.pfeg.noaa.gov/data_for_users/las.html>

Purpose:
"The frictional stress of equatorward wind on the ocean's surface, in concert with the effect of the earth's rotation, causes water in the surface layer to move away from the western coast of continental land masses. This offshore moving water is replaced by water which upwells, or flows toward the surface from depths of 50 to 100 meters and more. Upwelled water is cooler and saltier than the original surface water, and typically has much greater concentrations of nutrients such as nitrates, phosphates and silicates that are key to sustaining biological production. It is for this reason that marine ecosystems in the ocean's eastern boundary currents are highly productive, and capable of maintaining large standing crops of plankton, massive fish stocks such as sardines and anchovies, and major populations of marine mammals and sea birds. The major eastern boundary currents include the Canary off the Iberian peninsula and northwestern Africa, the Benguela off southwestern Africa, the Peru off western South America, and the California Current System off western North America. Moreover variations in upwelling over seasonal to interannual periods, due to large-scale shifts in wind patterns and atmospheric systems, are linked to variability in fish populations and other biological components in coastal ocean ecosystems." --Excerpted from PFEL Coastal Upwellling web site.
Supplemental_Information:
Metadata Contact: Sara Breslow Location: West Coast of North America Date Explanation: Based on FNMOC data collection times. Monthly anomaly data goes back to 1946; six hourly data begins 1967. Spatial Resolution: Stations Temporal Resolution: Six-Hourly; Daily; Monthly; Monthly Anomalies Data Processing Steps: "PFEL coastal upwelling indices are calculated based upon Ekman's theory of mass transport due to wind stress. Assuming homogeneity, uniform wind and steady state conditions, the mass transport of the surface water due to wind stress is 90° to the right of the wind direction in the Northern Hemisphere. Ekman mass transport is defined as the wind stress divided by the Coriolis parameter (a function of the earth's rotation and latitude). The depth to which an appreciable amount of this offshore transport occurs is termed the surface Ekman layer, and is generally 50 to 100 meters deep.

Ekman transports are resolved into components parallel and normal to the local coastline orientation. The magnitude of the offshore component is considered to be an index of the amount of water upwelled from the base of the Ekman layer. Positive values are, in general, the result of equatorward wind stress. Negative values imply downwelling, the onshore advection of surface waters accompanied by a downward displacement of water.

Historically, the indices were computed from monthly mean pressure fields prepared by FNMOC on a 3° mesh grid. After providing PFEL with several alternate pressure field grids over time, FNMOC currently produces six-hourly fields of surface pressure on a global spherical 1° mesh (a 180 x 360 grid). The standard west coast six-hourly upwelling indices are a product of the 3° pressure field interpolated from the 1° grid. Monthly indices are derived from a 3° mesh that is interpolated from the monthly-averages of the six-hourly 1° pressures." --Excerpted from PFEL Coastal Upwellling web site.

Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 1946
Ending_Date: Present
Status:
Progress: Complete
Maintenance_and_Update_Frequency: Monthly
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -150
East_Bounding_Coordinate: -105
North_Bounding_Coordinate: 60
South_Bounding_Coordinate: 20
Keywords:
Theme:
Theme_Keyword_Thesaurus: Oceanography
Theme_Keyword: Physical Oceanography
Theme_Keyword: Currents
Theme_Keyword: Chemical Oceanography
Theme_Keyword: Nutrients
Theme:
Theme_Keyword_Thesaurus: Ecosystems
Theme_Keyword: Coasts
Theme_Keyword: Hydrology
Theme_Keyword: Oceanography
Theme_Keyword: Water Quality
Theme_Keyword: Location
Theme_Keyword: Statistics
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: Coastal Upwelling Index
Theme_Keyword: Time Series
Theme_Keyword: Alongshore Ekman Transport
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: Upwelling
Theme_Keyword: California Current
Theme_Keyword: Ekman Transport
Theme_Keyword: Ekman Layer
Theme_Keyword: Geostrophic Winds
Theme_Keyword: Sea Level Pressure
Place:
Place_Keyword_Thesaurus: None
Place_Keyword: Pacific
Place_Keyword: West Coast
Place_Keyword: North America
Access_Constraints:
PFEL requests contact info and use plans via a form on their web site before linking to downloadable data.
Use_Constraints:
PFEL requires that all individuals downloading data from their web site acknowledge the source of the data in any reports, papers and presentations that are generated using the data.
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Jerold Norton
Contact_Address:
Address:
Pacific Fisheries Environmental Laboratory 1352 Lighthouse Ave.
City: Pacific Grove
State_or_Province: California
Postal_Code: 93950-2097
Country: USA
Contact_Voice_Telephone: (831) 648-8515
Contact_Facsimile_Telephone: (831) 648-8440
Contact_Electronic_Mail_Address: jnorton@pfeg.noaa.gov

Distribution_Information:
Distributor:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Jerold Norton
Contact_Address:
Address:
Pacific Fisheries Environmental Laboratory 1352 Lighthouse Ave.
City: Pacific Grove
State_or_Province: California
Postal_Code: 93950-2097
Country: USA
Contact_Voice_Telephone: (831) 648-8515
Contact_Facsimile_Telephone: (831) 648-8440
Contact_Electronic_Mail_Address: jnorton@pfeg.noaa.gov

Metadata_Reference_Information:
Metadata_Date: 19990525
Metadata_Review_Date:
Metadata_Future_Review_Date:

Generated by mp version 2.4.10 on Thu Sep 28 12:54:53 2000