Map climatic features as the long-term mean values (of atmospheric pressure, temperature, humidity, total precipitation, and so forth) to connect points with equal values of the feature in question—for example, isobars for pressure, isotherms for temperature, and isohyets for precipitation. Isoamplitudes are drawn on maps of amplitudes (for example, annual amplitudes of air temperature—that is, the differences between the mean temperatures of the warmest and coldest month). Isanomals are drawn on maps of anomalies (for example, deviations of the mean temperature of each place from the mean temperature of the entire latitudinal zone). Isolines of frequency are drawn on maps showing
Atmospheric-pressure laser ionization combined energy of the absorbed photons in this process must be above the ionization potential of the atom or molecule. In the simplest case, a single photon has sufficient energy to overcome the ionization potential. This process is therefore called single photon ionization, it is the basic principle of atmospheric pressure photoionization (APPI). For sufficiently high power densities of the incident light also nonlinear absorption processes like the absorption of at least two photons in a rapid sequence via virtual or real states can occur. If the combined energy of the absorbed photons is higher than the ionization potential, this