Internal wave effects on photosynthesis: Experiments, theory, and modeling

Evans, Mary Anne; MacIntyre, Sally; Kling, George W.

doi:10.4319/lo.2008.53.1.0339

Cited by 41 publications

(45 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We compute L N rather than W because we are interested in the dynamics of the seasonal thermocline and because of the difficulty in accurately specifying the top of the seasonal thermocline as needed to calculate W. The periods of first vertical mode internal waves (T 1 ) range from 9 h during weakly stratified conditions near ice-off to more typical summer values between 3 and 5 h (Evans et al 2008). L N was temporally filtered over J T 1 ; we set T 1 at 4 h. Stability was calculated following Idso (1973) and expressed as J m 22 .…”

Section: Methodsmentioning

confidence: 99%

Climate‐related variations in mixing dynamics in an Alaskan arctic lake

MacIntyre

Fram

Kushner

et al. 2009

Limnology & Oceanography

Self Cite

View full text Add to dashboard Cite

Mean epilimnetic temperatures from mid-June through mid-August in a small, arctic kettle lake had no trend from 1975 to 2008 and varied annually up to 63uC relative to the mean. Analysis of data from temperature arrays deployed on the lake from 1998 to 2007 showed that as mean summer temperatures shifted from 2.5uC below the mean, to the mean, and to 3uC above the mean, deepening of the mixed layer during cold fronts decreased, average metalimnetic thickness increased from 2 to 5 m, maximum values of water-column stability increased fourfold, minimum values of Lake numbers (L N ) increased from #1 to 10, the metalimnetic coefficient of eddy diffusivity (K z ) decreased from 10 25 m 2 s 21 to 10 27 m 2 s 21 , and time scales for mixing across the metalimnion increased from days to months. Mean surface temperatures and mixing regimes were significantly correlated with mean air temperatures, but not with mean insolation, or mean wind speeds during summer. They also depended upon the frequency and persistence of events with higher winds, heating, or cooling. In summers with cold surface temperatures, the surface energy fluxes that induce mixing by heat loss were low but with frequent wind events heat was mixed downwards, leading to lower stability. The warmest surface temperatures resulted when atmospheric conditions led to persistent positive buoyancy flux in early summer and winds were elevated primarily on diel cycles as opposed to longer ones. Summers with cooler water temperatures and enhanced vertical mixing are linked to frontal activity and low atmospheric pressure near the northern Alaskan coast.

show abstract

Section: Methodsmentioning

confidence: 99%

Climate‐related variations in mixing dynamics in an Alaskan arctic lake

MacIntyre

Fram

Kushner

et al. 2009

Limnology & Oceanography

Self Cite

View full text Add to dashboard Cite

show abstract

“…Indeed, depending on the depth of the peak biomass in the water column, the amount of light available differs considerably, which could potentially influence the growth rate of the cyanobacteria. Recently, the enhancement of photosynthesis induced by internal waves has been thoroughly investigated by Evans et al (2008), who used both experimentation and modeling to demonstrate that internal waves, combined with surface irradiance can cause marked increases or decreases in photosynthesis. In addition to their impact on the availability of light, internal waves could also influence that of nutrients, as evidenced for example in Lake Kinneret (Nishri et al, 2000).…”

Section: Discussionmentioning

confidence: 99%

Impact of internal waves on the spatial distribution of Planktothrix rubescens (cyanobacteria) in an alpine lake

et al. 2010

View full text Add to dashboard Cite

The vertical and horizontal distribution of the cyanobacterium, Planktothrix rubescens, was studied in a deep alpine lake (Lac du Bourget) in a 2-year monitoring program with 11 sampling points, and a 24-h survey at one sampling station. This species is known to proliferate in the metalimnic layer of numerous deep mesotrophic lakes in temperate areas, and also to produce hepatotoxins. When looking at the distribution of P. rubescens at the scale of the entire lake, we found large variations (up to 10 m) in the depth of the biomass peak in the water column. These variations were closely correlated to isotherm displacements. We also found significant variations in the distribution of the cyanobacterial biomass in the northern and southern parts of the lake. We used a physical modeling approach to demonstrate that two internal wave modes can explain these variations. Internal waves are generated by wind events, but can still be detected several days after the end of these events. Finally, our 24-h survey at one sampling point demonstrated that the V1H1 sinusoidal motion could evolve into nonlinear fronts. All these findings show that internal waves have a major impact on the distribution of P. rubescens proliferating in the metalimnic layer of a deep lake, and that this process could influence the growth of this species by a direct impact on light availability.

show abstract

“…Though the study of physical processes in lakes began nearly a century ago (Wedderburn, 1913), the role of wind forcing on lake processes is rarely studied (Mortimer, 1974;Imberger, 1980;Imboden et al, 1983, among others). The importance of physical forcing to biological processes in lakes has gained increasing recognition in the last three decades (Reynolds, 1994;Oftrosvky et al, 1996;Evans et al, 2008;Marcé et al, 2007). But, these studies were done in largemedium size lakes or reservoirs.…”

Section: Introductionmentioning

confidence: 99%