The map on the right shows the location of the three reservoirs (King Talal Dam, Al-Wihdeh Dam and Wadi Al-Arab Dam) within the lower Jordan watershed between Lake Tiberias and the Dead Sea.

<p>The morphological characteristics of the reservoirs are shown in the detailed maps on the left at different scales.</p

Time series of the monthly estimates of <i>p</i>CO₂ for (a) King Talal Dam (black), (b) Wadi Al-Arab Dam (green), and (c) Al-Wihdeh Dam (blue).

<p>The dashed lines show the mean atmospheric <i>p</i>CO₂ (396 μatm).</p

Time series of the physico-chemical parameters in three reservoirs King Talal Dam (black), Wadi Al-Arab (green) and Al-Wihdeh (blue): (a) Daily mean surface area, (b) daily mean water volume, (c) water surface temperature, (d) alkalinity, and (e) pH.

<p>Time series of the physico-chemical parameters in three reservoirs King Talal Dam (black), Wadi Al-Arab (green) and Al-Wihdeh (blue): (a) Daily mean surface area, (b) daily mean water volume, (c) water surface temperature, (d) alkalinity, and (e) pH.</p

Time series of the CO₂ flux for the three reservoirs in (a) King Talal Dam (black), (b) Wadi Al-Arab Dam (green), and (c) Al-Wihdeh Dam (blue).

<p>The y-axes is in different scale and the dashed lines were fixed at zero.</p

Cross-correlation coefficients for the selected parameters: pH, alkalinity (<i>Alk</i>) in mmol l^-1, salinity (<i>S</i>) in ppt, temperature (<i>T</i>) in °C, <i>p</i>CO₂ in μatm, CO₂ flux (Flux) in mg CO₂ m^-2 d^-1, water volume (<i>V</i>) in m³, gas exchange velocity (<i>k</i>’₆₀₀) in m d^-1 and chemical enhancement factor (<i>α</i>).

<p>For each combination of parameters, the three numbers are the cross-correlation coefficients observed for King Talal (upper), Wadi Al-Arab (middle) and Al-Wihdeh (lowest) dams. The most significant correlation coefficients (<i>p</i><0.05) are marked bold, while <i>p</i><0.1 for the remaining correlations. Not significant correlations are marked as x.</p

Chemical enhancement factor as a function of unenhanced gas exchange velocity <i>k’</i>_CO2 for three different pH values (color) and at two different temperatures (solid line: 25°C, dashed line: 7°C).

<p>The dotted line indicates a reciprocal relationship between both parameters and therewith a resulting exchange coefficient, which is independent of wind speed. Chemical enhancement further depends on salinity, which was fixed at a value of 0.8 ppt.</p

Summary of the measured and estimated physico-chemical variables and CO₂ fluxes for the three reservoirs.

<p><i>n</i> indicates the number of available water chemistry samples. All numbers are given as mean±SD. The arrows in parentheses indicate significant linear temporal trends (↑ increasing, ↓ decreasing,—not significant for <i>p</i><0.05).</p

The main physical characteristics of the three reservoirs.

<p>Numbers are provided as mean±SD (standard deviation), if available.</p

The frequency distribution of (a) gas exchange velocity and (b) chemical enhancement factor for the three reservoirs.

<p>The frequency distribution of (a) gas exchange velocity and (b) chemical enhancement factor for the three reservoirs.</p

Atmospheric fluxes of CO₂ as a function of pH in the three reservoirs.

<p>R2 denote to the linear regression.</p