A new method to generate a high-resolution global distribution map of lake chlorophyll

International Journal of Remote Sensing
By: , and 

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Abstract

A new method was developed, evaluated, and applied to generate a global dataset of growing-season chlorophyll-a (chl) concentrations in 2011 for freshwater lakes. Chl observations from freshwater lakes are valuable for estimating lake productivity as well as assessing the role that these lakes play in carbon budgets. The standard 4 km NASA OceanColor L3 chlorophyll concentration products generated from MODIS and MERIS sensor data are not sufficiently representative of global chl values because these can only resolve larger lakes, which generally have lower chl concentrations than lakes of smaller surface area. Our new methodology utilizes the 300 m-resolution MERIS full-resolution full-swath (FRS) global dataset as input and does not rely on the land mask used to generate standard NASA products, which masks many lakes that are otherwise resolvable in MERIS imagery. The new method produced chl concentration values for 78,938 and 1,074 lakes in the northern and southern hemispheres, respectively. The mean chl for lakes visible in the MERIS composite was 19.2 ± 19.2, the median was 13.3, and the interquartile range was 3.90–28.6 mg m−3. The accuracy of the MERIS-derived values was assessed by comparison with temporally near-coincident and globally distributed in situmeasurements from the literature (n = 185, RMSE = 9.39, R2 = 0.72). This represents the first global-scale dataset of satellite-derived chl estimates for medium to large lakes.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title A new method to generate a high-resolution global distribution map of lake chlorophyll
Series title International Journal of Remote Sensing
DOI 10.1080/01431161.2015.1029099
Volume 36
Issue 7
Year Published 2015
Language English
Publisher Taylor & Francis
Contributing office(s) Great Lakes Science Center
Description 23 p.
First page 1942
Last page 1964
Online Only (Y/N) N
Additional Online Files (Y/N) N