Density Altitude Maps of Iran and Iraq

This report provides maps of Iran and Iraq with contours of mean monthly density altitude at the surface near the times of maximum and minimum temperatures. Surface values of temperature, vapor pressure, and pressure used to calculate DA were adjusted at each grid point using gridded terrain elevation from the Defense Mapping Agency DMA 100-meter digital terrain database DTED. Density altitude DA is pressure altitude PA corrected for nonstandard temperature and dew-pointed variations. PA is the altitude indicated by an altimeter when it is set to the standard datum plane of 29.92 inches of mercury. When conditions are standard, PA and DA are the same. If temperature is above standard, DA is higher than PA. If temperature is below standard, DA is lower than PA. DA can also be expressed as the altitude in the ICAO standard atmosphere at which a given density occurs. The maps produced in this study show the altitude in the ICAO standard atmosphere at which surface density occurs.