Vapour-pressure deficit temperature, the relative humidity and, if possible, the canopy air temperature. We must then compute the saturation pressure. Saturation pressure can be looked up in a psychrometric chart or derived from the Arrhenius equation, a way to compute it directly from temperature is where: To convert between Rankine and degrees Fahrenheit: formula_10 We compute this pressure for both the ambient and canopy temperatures. We then can compute the actual partial pressure of the water vapour in the air by multiplying by the relative humidity [%]: and finally VPD using formula_12 or formula_13 when the canopy temperature is known. Vapour-pressure deficit
High-water mark of the Confederacy High-water mark of the Confederacy The high-water mark of the Confederacy refers to an area on Cemetery Ridge near Gettysburg, Pennsylvania, marking the farthest point reached by Confederate forces during Pickett's Charge on July 3, 1863. Similar to a high water mark of water, the term is a reference to arguably the Confederate Army's best chance of achieving victory in the war. The line of advance was east of "The Angle" stone wall at various distances, e.g., the Virginians pushed the Union line back. This designation was invented by government historian John B. Bachelder after the war when the monuments