CCE banner
 
Funded Research

Decadal Changes in the Equatorial Pacific Ecosystem Structure and Functioning: Impact of Climate Conditions

Wang, Xiujun (Wendy): UMD/ESSIC (Project Lead)
McPhaden, Michael: NOAA (Institution Lead)

Project Funding: 2009 - 2012

NRA: 2008 NASA: Ocean Biology and Biogeochemistry   

Funded by NASA

Abstract:
The equatorial Pacific undergoes significant physical and biogeochemical changes at interannual to decadal and longer time scales. Observational studies have identified two possible regime shifts in physical processes around 1976/77 and 1998/99, associated with substantial changes of the shallow meridional overturning circulation, the Pacific Subtropical Cells that link the subtropical subduction and tropical upwelling in the Pacific. However, little is known about their impacts on the equatorial Pacific biogeochemistry, and decadal and interdecadal changes in the equatorial Pacific ecosystem structure and functioning. Here, we propose a combined study employing in situ and satellite data, and an advanced dynamic ecosystem model to address this issue. Our approach includes two major parts: (1) the use of in situ and satellite derived data for model calibration and validation, and (2) the analyses of modeled biological parameters during the period of 1950-2008. The objectives of the proposed study are to (1) to study how decadal to interdecadal variability of the physical processes regulate the biogeochemical processes, particularly nutrient transportation; (2) to study how past and present climate conditions regulate the spatial distribution and temporal variability in the marine ecosystem structure (e.g., phytoplankton vs. zooplankton, and large cells vs. small cells); (3) to determine the magnitude of the regional primary and secondary productivity for the past 50 years, and the impacts of the marine ecosystem dynamics; and (4) to compare key biological parameters among three periods: 1950-1976, 1980-1996, and 1998-2008, and to determine if there are systematic shifts. The proposed work seeks to understand decadal changes in ocean biology and related climate conditions, which is a critical objective of the solicitation. This proposal also addresses two of the NASA’s research objectives: (1) quantify marine productivity, and improve carbon cycle and ecosystem models; and (2) understand the role of oceans in the climate system.


More details may be found in the following project profile(s):