Impact of partly ice-free Lake Ladoga on temperature and cloudiness in an
                        anticyclonic winter situation – a case study using a limited area
                        model

Eerola, Kalle; Rontu, Laura; Kourzeneva, Ekaterina; Pour, Homa Kheyrollah; Duguay, Claude R.

doi:10.3402/tellusa.v66.23929

Cited by 35 publications

(43 citation statements)

References 20 publications

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“…To examine the sensitivity of different analytical formulations of the empirical autocorrelation functions in HIRLAM objective analysis of LSWT, we compare its results to independent observations. The present study builds on the work reported by Kheyrollah Pour et al (2014b) on the use of satellite measurements for LSWT data assimilation in HIRLAM and on the influence of the lake surface state in weather forecast by Eerola et al (2014). To our knowledge, this is the first study of its kind which could lead to an improved definition of the LSWT autocorrelation function and thus to a better objective analysis of LSWT in NWP models.…”

Section: Introductionmentioning

confidence: 86%

“…Hence, we run only short (+6h) HIRLAM forecasts to provide background for the next analysis-forecast cycle. For the meteorological impact of the initial LSWT analysis on the forecast we refer to the detailed discussion in a case study over the freezing Lake Ladoga by Eerola et al (2014).…”

Section: The Set-up Of the Hirlam Experimentsmentioning

confidence: 99%

“…The surface data assimilation methods and parametrisations of atmospheric and surface processes relevant for this study were described in Eerola et al (2014). In our experiments, only the surface data assimilation was applied, while the upper air analysis was replaced by the interpolated fields from the ECMWF analyses.…”

Section: The Set-up Of the Hirlam Experimentsmentioning

confidence: 99%

“…The surface heat, moisture and momentum fluxes depend not only on atmospheric conditions but also on the properties of the land cover, which in lake-rich areas are largely determined by inland water bodies. The importance of a correct description of inland water (lake) surface state is well known in climate modelling (Duguay et al, 2006;Brown and Duguay, 2010;Krinner and Boike, 2010;Samuelsson et al, 2010;Ngai et al, 2013) and in numerical weather prediction (Niziol, 1987;Niziol et al, 1995;Zhao et al, 2012;Eerola et al, 2014). For example, during freezing and melting the lake surface radiative and conductive * Corresponding author.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Towards improved objective analysis of lake surface water temperature in a NWP model: preliminary assessment of statistical properties

Pour

Choulga

Eerola

et al. 2017

Tellus A: Dynamic Meteorology and Oceanography

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Information about the statistical structure of the lake surface water temperature (LSWT) field is needed for assimilation of lake observations into Numerical Weather Prediction (NWP) models, to describe the lake surface state at each gridpoint containing lakes. In this study, we obtain the autocorrelation function for LSWT from two types of observations, in situ and satellite-based. We use summer time measurements during 2010-2014 over selected Fennoscandian lakes and Northern European domain. The estimated autocorrelations decrease exponentially (from 0.99 to 0.73 for in situ and from 0.97 to 0.61 for satellite observations), when the distance between observations increases from zero to one thousand kilometres .A large difference in lake depth leads to a decrease of the correlation. Typical error standard deviation of LSWT observations was found to be 0.9 • C for in situ observations and 1.2 • C for satellite observations. The exponential approximation for the LSWT autocorrelation functions is proposed, which depends on both the distance and the difference in lake depth. These results are directly applicable for the LSWT objective analysis in NWP. New autocorrelation functions, which allow interpolation of observations within and between lakes, were used in numerical experiments with the High-Resolution Limited Area Model (HIRLAM). In this preliminary assessment, we suggest adaptation of the presently used functions by increasing the influence radius and taking into account the lake depth difference. Generalization of the results to cover the melting and freezing seasons, their assessment for different geographical areas as well as their application to other prognostic lake variables within NWP are foreseen.

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Section: Introductionmentioning

confidence: 86%

Section: The Set-up Of the Hirlam Experimentsmentioning

confidence: 99%

Section: The Set-up Of the Hirlam Experimentsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Towards improved objective analysis of lake surface water temperature in a NWP model: preliminary assessment of statistical properties

Pour

Choulga

Eerola

et al. 2017

Tellus A: Dynamic Meteorology and Oceanography

Self Cite

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“…However, regional thermodynamic and dynamic effects of lakes on weather and climate are important for most of Canada, Finland, western Siberia and some other regions (Dutra et al, 2010;Martynov et al, 2012;Eerola et al, 2014). This motivated the inclusion of thermodynamic lake models into many numerical weather prediction (NWP) and climate models (Martynov et al, 2012;Dutra et al, 2010;Mironov et al, 2010;Subin et al, 2012;Rontu et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

LAKE 2.0: a model for temperature, methane, carbon dioxide and oxygen dynamics in lakes

et al. 2016

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Abstract. A one-dimensional (1-D) model for an enclosed basin (lake) is presented, which reproduces temperature, horizontal velocities, oxygen, carbon dioxide and methane in the basin. All prognostic variables are treated in a unified manner via a generic 1-D transport equation for horizontally averaged property. A water body interacts with underlying sediments. These sediments are represented by a set of vertical columns with heat, moisture and CH 4 transport inside. The model is validated vs. a comprehensive observational data set gathered at Kuivajärvi Lake (southern Finland), demonstrating a fair agreement. The value of a key calibration constant, regulating the magnitude of methane production in sediments, corresponded well to that obtained from another two lakes. We demonstrated via surface seiche parameterization that the near-bottom turbulence induced by surface seiches is likely to significantly affect CH 4 accumulation there. Furthermore, our results suggest that a gas transfer through thermocline under intense internal seiche motions is a bottleneck in quantifying greenhouse gas dynamics in dimictic lakes, which calls for further research.

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Bulk Transfer Coefficients Estimated from Eddy-Covariance Measurements over Lakes and Reservoirs

Guseva

Armani

Desai

et al. 2022

Preprint

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The drag coefficient, Stanton number and Dalton number are of particular importance for estimating the surface turbulent fluxes of momentum, heat and water vapor using bulk parameterization. Although these bulk transfer coefficients have been extensively studied over the past several decades in marine and large-lake environments, there are no studies analyzing their variability for smaller lakes. Here, we evaluated these coefficients through directly measured surface fluxes using the eddy-covariance technique over more than 30 lakes and reservoirs of different sizes and depths. Our analysis showed that the transfer coefficients (adjusted to neutral atmospheric stability) were generally within the range reported in previous studies for large lakes and oceans. All transfer coefficients exhibit a substantial increase at low wind speeds (<3 m s −1 ), which was found to be associated with the presence of gusts and capillary waves (except Dalton number). Stanton number was found to be on average a factor of 1.3 higher than Dalton number, likely affecting the Bowen ratio method. At high wind speeds, the transfer coefficients remained relatively constant at values of 1.6•10 −3 , 1.4•10 −3 , 1.0•10 −3 , respectively. We found that the variability of the transfer coefficients among the lakes could be associated with lake surface area. In flux parameterizations at lake surfaces, it is recommended to consider variations in the drag coefficient and Stanton number due to wind gustiness and capillary wave roughness while Dalton number could be considered as constant at all wind speeds. Plain Language SummaryIn our study, we investigate the bulk transfer coefficients, which are of particular importance for estimation the turbulent fluxes of momentum, heat and water vapor in the atmospheric surface layer, above lakes and reservoirs. The incorrect representation of the surface fluxes above inland waters can potentially lead to errors in weather and climate prediction models. For the first time we made this synthesis using a compiled data set consisting of existing eddy-covariance flux measurements over 23 lakes and 8 reservoirs. Our results revealed substantial increase of the transfer coefficients at low wind speeds, which is often not taken into account in models. The observed increase in the drag coefficient (momentum transfer coefficient) and Stanton number (heat transfer coefficient) could be associated with the presence of wind gusts and capillary waves. In flux parameterizations at lake surface, it is recommended to consider them for accurate flux representation. Although the bulk transfer coefficients were relatively constant at high wind speeds, we found that the Stanton number systematically exceeds the Dalton number (water vapor transfer coefficient), despite the fact they are typically considered to be equal. This difference may affect the Bowen ratio method and result in biased estimates of lake evaporation.

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Impact of partly ice-free Lake Ladoga on temperature and cloudiness in an anticyclonic winter situation – a case study using a limited area model

Cited by 35 publications

References 20 publications

Towards improved objective analysis of lake surface water temperature in a NWP model: preliminary assessment of statistical properties

Towards improved objective analysis of lake surface water temperature in a NWP model: preliminary assessment of statistical properties

LAKE 2.0: a model for temperature, methane, carbon dioxide and oxygen dynamics in lakes

Bulk Transfer Coefficients Estimated from Eddy-Covariance Measurements over Lakes and Reservoirs

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