Evaluation of the Sensitivity of the Amazonian Diurnal Cycle to Convective Intensity in ReanalysesModel parameterizations of tropical deep convection are unable to reproduce the observed diurnal and spatial variability of convection in the Amazon, which contributes to climatological biases in the water cycle and energy budget. Convective intensity regimes are defined using percentiles of daily minimum 3-hourly averaged outgoing longwave radiation (OLR) from Clouds and the Earth's Radiant Energy System (CERES). This study compares the observed spatial variability of convective diurnal cycle statistics for each regime to MERRA-2 and ERA-Interim (ERA) reanalysis data sets. Composite diurnal cycle statistics are computed for daytime hours (06:00-21:00 local time) in the wet season (December-January-February). MERRA-2 matches observations more closely than ERA for domain averaged composite diurnal statistics-specifically precipitation. However, ERA reproduces mesoscale features of OLR and precipitation phase associated with topography and the propagation of the coastal squall line. Both reanalysis models are shown to underestimate extreme convection.
Document ID
20170003227
Acquisition Source
Langley Research Center
Document Type
Conference Paper
Authors
Itterly, Kyle F. (Science Systems and Applications, Inc. Hampton, VA, United States)
Taylor, Patrick C. (NASA Langley Research Center Hampton, VA, United States)
Date Acquired
April 7, 2017
Publication Date
April 16, 2016
Subject Category
Statistics And ProbabilityMeteorology And Climatology
Report/Patent Number
NF1676L-25238
Meeting Information
Meeting: International Radiation Symposium (IRS) 2016