PBL parameterization schemes analysis over the central Amazon basin during GoAmazon 2014/5 experiment

The boundary layer characteristics at Central Amazonia were studied using the WRF model, with a domain of 3 one-way interacting nested grids. The results from the inner domain (1 km) for different PBL schemes (nonlocal (ACM2, MRF, SH, YSU, QNSE-EDMF) and local (BouLac, GBM, MYNN2.5, MYNN3, MYJ, UW)) were analyzed against in situ observations. This validation dataset was made during the GoAmazon 2014/5 experiment. The PBL heights (PBLH) were compared with ceilometer (Vaisala Oy, Finland) measurements installed during the field work. Short-term forecasts (72-h) were conducted (with a 12 h spin-up) for 4 different and typical cases: rainy and dry seasons for a typical (2014) and an ENSO-influenced (2015) years. The statistical analysis was performed separately for daytime and nighttime due to the pronounced diurnal variation, which revealed that the PBLH is better predicted during daytime. The local schemes (MYNN2.5, MYNN3, MYJ) give reasonable estimates for the convective boundary layer and non-local scheme (SH) for stable conditions. The diagnosed PBLH spatial fields for nighttime (02 Local Time – UTC-4 h) and daytime (14 LT) were investigated. The PBLH spatial fields revealed that nonlocal PBL schemes are influenced by the hydrography, while local PBL schemes were not. In general, the local MYNN2.5 and MYNN3 and the nonlocal QNSE-EDMF schemes predicted a deeper PBLH. Nonlocal schemes (ACM2 and MRF) depict the hydrography in their PBLH distribution with higher PBLH over the land (> 1500 m) and lower over the water bodies (< 800 m) during the daytime. The same typical values for nighttime are 100-200 m over the continent and 50-100 m over the water. The values during ENSO (2015) were higher than for the typical year (2014).