![]() Near the surface, as saturated air rises, it expands and begins to cool at a rate of about 4☌ per 1,000 meters (2.2☏/1,000 feet). When the air is at 100% relative humidity, further cooling causes water vapor to condense. In this condensation process, heat is released, which then affects the rate of cooling these lines represent that rate. Moist adiabats represent the rate at which saturated air cools (lapses) as it rises. These curved lines increase in value (☌) from left to right. This rate is called the "dry adiabatic lapse rate" and these lines on the Skew-T represent that value. As unsaturated air rises, it expands and cools with the temperature decreasing (or lapses) at a rate of 9.8☌ per 1,000 meters (5.5☏/1,000 feet) until the relative humidity becomes 100% (the air becomes saturated). Dry adiabats represent the rate at which unsaturated air cools as it rises (Unsaturated air is air with a relative humidity lower than 100%.). Slightly curved, these lines increase in value (☌) from lower left to upper right. Therefore, the heights of the various pressure levels are plotted as the "logarithm" of the pressure, the "Log-P" portion of the Skew-T Log-P diagram. This is due to the decrease in atmospheric density with increasing elevation ( Learn more about atmospheric density).Ītmospheric pressure decreases logarithmically with increasing elevation. Distance between the lines increases from the bottom of the chart (1050 millibars) to the top (100 millibars). Pressure lines are drawn in the horizontal. This is where the name "Skew-T" comes from as the temperature lines are skewed at a 45° angle. However, in 1947, the diagram was modified by tilting the temperature lines 45°, aiding in analysis. Early versions of this upper air chart were made with the temperature lines drawn in the vertical. Temperature lines are drawn at a 45° angle with temperature values that increase from the upper left to the lower right corner of the chart. (You can toggle on/off each of these lines on the image at bottom.) There are six basic set of fixed lines that comprise the skew-t diagram. From these basic values, a wealth of information can be obtained concerning the meteorological condition of the upper air. Once the radiosonde observation is plotted, the Skew-T will show the temperature, dew point, and wind speed/direction. National Centers for Environmental Prediction. ![]() Preparedness and Mitigation: Individuals (You!).Preparedness and Mitigation: Communities.The Positive and Negative Side of Lightning.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |