HydroMet buoy - Meteorology

2019-2020 Meteorological time series 

Figure 23 - Temporal evolution of air temperature (ºC). It follows a parabolic curve (in relation to the cycle of the height of the sun on the horizon) with maximums in the rainy period (November - February) and minimums in the dry period (June - August). It fluctuated between 0.1 ºC and 17.1 ºC, with an average of 9.6 ºC. It can be noted that on the surface of the lake the air temperature does not freeze (i.e. does not pass negative). During the dry season the daily thermal amplitude is greater (ranges up to 16 ºC) than in the rainy season (ranges up to 9 ºC).

Figure 24 - Time evolution of the atmospheric pressure (barometric; in mm Hg). During the dry and wet seasons, it ranged between 482 and 489 mm Hg, with a period of 2-3 days and an average of 485 mm Hg. The daily amplitude is +/- 3 mm Hg, with slightly lower pressures in the transition season (December).

Figure 25 - Time evolution of the average wind speed (in 5 min intervals; in m/s). Thermal winds increase daily in the afternoons, generated by differences of about 5 ºC between the air and the (warmer) water. Winds average 4.6 m/s (17 km/h), rarely exceed 10 m/s (36 km/h), exceptionally reach 17 m/s (61 km/h). Wind speed can change in a few hours and from one day to the next, over cycles of several days. The strongest winds occurred in July 2019, and especially in February-March 2020. They were weakest in July-August 2019. Some periods of no data were observed.

Figure 26 - Time evolution of the average wind direction (in 5 min intervals; in º). The wind that usually starts blowing in the afternoon changes direction daily over 360º.

Figure 27 - Time evolution of relative air humidity (%). During the dry season the amplitude was greater (11 - 95 %), than during the wet period (January, 30 - 90 %). During the year it fluctuated between 11 and 95 %, with an average of 63.5 %.

Figure 28 - Time evolution of precipitation (rainfall). Rainfall (storms) occurred mainly between November and March, and was more intense (up to 10 mm / 5 min) and frequent in January-February.

Figure 29 - Time evolution of hailstorms. It occurred mostly during January-March, with a maximum of 0.7 strokes/cm2 on 01/29/2020 at 13:16.

Figure 30 - Time evolution of incident visible solar radiation (400-1100 nm, in W/m2). This quantameter was installed on the buoy on 08/29/2020. The radiation oscillated with periods of 2-3 weeks, with a great homogeneity between dry and rainy season (maximum 511 W/m2). From mid-May, it decreased to 250 W/m2.