Study of the Basic Conception and Assessment Method of Atmospheric Water and Cloud Water Resources

Based on atmospheric water cycle，the concepts of atmospheric water resource(AWR) and cloud water resource(CWR) are proposed, two assessment methods are established, including observation diagnosis and numerical simulation. Through typical months resource assessment, the physical characteristics of AWR/CWR are revealed. Mainly results are as follows. (1) AWR/CWR refers to atmospheric water /atmospheric hydrometeor which participates atmospheric water cycle in a certain region and period, fails to form natural precipitation, and remains in the atmosphere to be developed and utilized. Atmospheric water species status, inflow and outflow, cloud condensation and evaporation, surface evaporation and precipitation are considered in the definition. (2) The definitions and calculation formulas of 27 physical quantities are proposed from four-dimensional integral of atmospheric water balance equation, such as AWR, CWR and its components. (3) Observation diagnosis assessment on atmospheric water/cloud water resource(A/CWR-ODA) is established based on atmosphere, cloud and precipitation observation, as well as numerical simulation assessment(ACWR-NSA) based on mesoscale atmospheric cloud-resolved numerical model prediction system. (4) Typical months assessment of North China indicates that, AWR is 1～2 orders of magnitude larger than precipitation. There is no significant correlation between surface precipitation and atmospheric water status quantity, horizontal moisture flow or AWR. CWR is one order of magnitude smaller than AWR. Comparing to water vapor, the atmospheric hydrometeor status quantity and horizontal flow are two orders of magnitude smaller, but it has much shorter renewal cycle period and much higher precipitation efficiency. Therefore, it is more reasonable to use atmospheric hydrometeor and CWR to study precipitation. (5) From the perspective of development and surface precipitation enhancement, CWR is more suitable than AWR or water vapor. CWR can be developed by increasing cloud condensation or reducing cloud evaporation, outflow and final status quantity, it will not simply cause the decrease of downstream precipitation.