After having dived into Mistral and Sirocco winds in previous articles, today it is time to take a closer look at another less-known wind in Asia, blowing in the Caspian Sea: the Bautino effect.
Introduction
Spatial weather forecasting is divided into several categories, depending on the scale. Starting from the planetary scale (> 10,000 km), which includes global processes such as global atmospheric circulation, jet streams and planetary waves, and ending with microscale processes (< 2 km), which include turbulence, gusts, interaction of the atmosphere with relief, etc.
When making a weather forecast, the forecaster must take into account local features, that is, apply a microscale forecast in conjunction with a larger-scale one. Thus, the weather forecast becomes more accurate. Often, local processes that always take place under certain conditions are given a name. For example, the Sirocco effect, the Meltemi effect, the Bautino effect, etc. Today we will discuss the Bautino effect in detail.
Location and local features
The Bautino Effect is named after its location, a small village in Kazakhstan on the shores of the northern Caspian Sea (Figure 1-2). The peculiarity of Bautino's location is that it is a port village located between mountains. Such orography contributes to the occurrence of a funneling effect with any movement of air with an eastern component.
Figure 1 Location of Bautino
Figure 2 Location of Bautino, close-up.
The peculiarity of Bautino's location is that it is a port village located between mountains. Such orography contributes to the occurrence of a funneling effect with any movement of air with an eastern component. In addition to this, it is worth noting that the depth to the north of Bautino is significantly less than to the west. This contributes to greater heating and cooling of waters with a greater amplitude to the north of the village, resulting in a stronger seasonal land sea circulation in autumn and spring. Such features are local in nature with a scale of less than 10 km, and often the models simply do not *see* this wind effect.
When does the Bautino Effect appear?
Based on many years of observations, south winds prevail over north winds. They also behave differently, so let's look at them separately.
When the wind blows from SSE and ESE, the air flows around the plateau of the Tyub-Karagan Peninsula, probably accelerating even more along the valley (if the flow comes from SE and E). The flow also accelerates along the western coast over the sea surface when the flow is from S/SE (Figure 3).
Figure 3 Southeasterly funneling
Thermal anticyclone over land can also slightly strengthen the flow coming from the S and E. This is also observed at night when a breeze from the land is formed (Figures 4, 5). During stable conditions (when the temperature increases sharply with height) such funnelings can be strengthened, this most often occurs at night.
Figure 4 Land breeze
Figure 5 Thermal anticyclone over the plateau
As for the north-east winds, they accelerate along the cape and then move south, strengthening along the cliffs (Figure 6). This often happens with a sea land circulation (Figure 7) or with a broader thermal cyclone over the plateau (Figure 8). Funneling can also increase with a more stable air mass, as air can become trapped between inversion and the plateau.
Figure 6 Northeasterly funneling
Figure 7 Sea-land circulation
Figure 8 Thermal cyclone over the plateau
Conclusion
Thus, we have analyzed the conditions under which the Bautino effect occurs for its full understanding. At Infoplaza Marine Weather, our meteorologists, taught by many years of experience, know what to do in these situations. Every day, our forecasters monitor the weather to take into account all the features of weather conditions, to make the most accurate weather forecast.
In a few weeks’ time, this series will be continued with another wind phenomenon which takes place at the Aegean Sea: the Meltemi wind, also known as Etesians. For more information, in-depth articles or updates related to this week's North Sea weather, please look at our website.
