The Distribution and Prediction of Summer Near-Surface Water Temperatures in Lakes of the Coterminous United States and Southern Canada

Roger W Bachmann,Sapna Sharma,Vincent Lecours,Daniel E Canfield

doi:10.3390/geosciences9070296

Roger W Bachmann, Sapna Sharma + Show 2 more

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https://doi.org/10.3390/geosciences9070296

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Journal: Geosciences	Publication Date: Jul 5, 2019
Citations: 5	License type: CC BY 4.0

Affiliation: York University, University of Florida

Abstract

The goals of the study were: (i) To describe the distribution of summer near-surface water temperatures in lakes of the coterminous United States and southern Canada (ii) to determine the geographic, meteorological and limnological factors related to summer water temperatures and (iii) to develop and test predictive models for summer near-surface water temperatures. We used data from the United States National Lakes Assessments of 2007 and 2012 as well as data collected from several different studies of Canadian lakes. Using multiple regressions, we quantified the general observations that summer water temperatures decreased when going from south to north, from east to west, and from lower elevations to higher elevations. Our empirical model using 8-day average air temperatures, latitude, longitude, elevations and month was able to predict water temperatures in individual lakes on individual summer days with a standard deviation of 1.7 °C for United States lakes and 2.3 °C for lakes in the southern regions of Canada.

Highlights

Summer near-surface lake water temperatures in lakes are highly important to physical, chemical and biological properties of lakes, including lake stratification [1], likelihood of algal blooms [2,3] and distribution of aquatic plants and animals [4]
We noted the elevations of the lakes tended to be highest in the western parts of the United States and Canada reflecting the location of the western mountains (Figure 2d)
For the Canadian lakes we found that once we had accounted for the 8-day air temperature, latitude, longitude, elevation and month the addition of the year of sampling did not significantly reduce the Akaike information criterion (AIC) or the RMSE (Table 4)

Summary

Introduction

Summer near-surface lake water temperatures in lakes are highly important to physical, chemical and biological properties of lakes, including lake stratification [1], likelihood of algal blooms [2,3] and distribution of aquatic plants and animals [4]. Near-surface summer water temperatures are warming in lakes worldwide, with over 90% of observed lakes exhibiting warming trends [5,6,7,8]. Warmer near-surface water temperatures in north temperate lakes are contributing to the northward range expansion of warmwater fishes, such as the smallmouth bass [9,10]. Hondzo and Stefan [17] used mean daily values for six meteorological variables, solar radiation, air temperature, dew point temperature, wind speed, wind direction and precipitation to estimate near-surface water temperatures for Minnesota lakes. Latitudinal and altitudinal gradients in air temperature and solar radiation reflect the importance of lake geography in explaining near-surface water temperatures [6,15]. It is generally understood that lakes in southern latitudes are warmer than those in the north, and that those lakes located at higher elevations are cooler than those at lower elevations

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