Atlantic Tropical Cyclogenetic Processes During Sop-3 Namma in the Geos-5 Global Data Assimilation and Forecast System

Abstract This article investigates the role of the Saharan air layer (SAL) in tropical cyclogenetic processes associated with a nondeveloping and a developing African easterly wave observed during the Special Observation Period (SOP-3) phase of the 2006 NASA African Monsoon Multidisciplinary Analyses (NAMMA). The two waves are chosen because they both interact heavily with Saharan air. A global data assimilation and forecast system, the NASA Goddard Earth Observing System, version 5 (GEOS-5), is being run to produce a set of high-quality global analyses, inclusive of all observations used operationally but with additional satellite information. In particular, following previous works by the same authors, the quality-controlled data from the Atmospheric Infrared Sounder (AIRS) used to produce these analyses have a better coverage than the one adopted by operational centers. From these improved analyses, two sets of 31 five-day high-resolution forecasts, at horizontal resolutions of both half and quarter de...

[1]  T. Dunkerton,et al.  Tropical cyclogenesis in a tropical wave critical layer: easterly waves , 2008 .

[2]  Menas Kafatos,et al.  Contrasting the 2007 and 2005 hurricane seasons: Evidence of possible impacts of Saharan dry air and dust on tropical cyclone activity in the Atlantic basin , 2008 .

[3]  Shian‐Jiann Lin.  A “Vertically Lagrangian” Finite-Volume Dynamical Core for Global Models , 2004 .

[4]  G. Jenkins,et al.  Saharan dust, lightning and tropical cyclones in the eastern tropical Atlantic during NAMMA‐06 , 2008 .

[5]  T. Carlson,et al.  The Large-Scale Movement of Saharan Air Outbreaks over the Northern Equatorial Atlantic , 1972 .

[6]  Kyu-Myong Kim,et al.  Cooling of the Atlantic by Saharan dust , 2007 .

[7]  Christopher D. Barnet,et al.  Accuracy of geophysical parameters derived from Atmospheric Infrared Sounder/Advanced Microwave Sounding Unit as a function of fractional cloud cover , 2006 .

[8]  Christopher A. Davis,et al.  The Role of “Vortical” Hot Towers in the Formation of Tropical Cyclone Diana (1984) , 2004 .

[9]  George N. Kiladis,et al.  Three-Dimensional Structure and Dynamics of African Easterly Waves. Part I: Observations , 2006 .

[10]  Y. Hong,et al.  The TRMM Multisatellite Precipitation Analysis (TMPA): Quasi-Global, Multiyear, Combined-Sensor Precipitation Estimates at Fine Scales , 2007 .

[11]  Ruixin Yang,et al.  Numerical Simulations of the Impacts of the Saharan Air Layer on Atlantic Tropical Cyclone Development , 2009 .

[12]  E. Brin,et al.  Improving forecast skill by assimilation of quality‐controlled AIRS temperature retrievals under partially cloudy conditions , 2008 .

[13]  Oreste Reale,et al.  Preliminary evaluation of the European Centre for Medium‐Range Weather Forecasts' (ECMWF) Nature Run over the tropical Atlantic and African monsoon region , 2007 .

[14]  K. Cook,et al.  Generation of African Easterly Wave Disturbances: Relationship to the African Easterly Jet , 2005 .

[15]  Liguang Wu,et al.  Analysis of the influence of Saharan air layer on tropical cyclone intensity using AIRS/Aqua data , 2009 .

[16]  Edward V. Browell,et al.  LASE Measurements of Water Vapor, Aerosol, and Cloud Distributions in Saharan Air Layers and Tropical Disturbances , 2010 .

[17]  Robert W. Burpee.  Characteristics of North African Easterly Waves During the Summers of 1968 and 1969 , 1974 .

[18]  C. Sui,et al.  Mechanisms of Cloud-radiation interaction in the tropics and midlatitudes , 1996 .

[19]  C. Guard,et al.  Tropical Cyclone Report , 1989 .

[20]  Scott A. Braun,et al.  Reevaluating the Role of the Saharan Air Layer in Atlantic Tropical Cyclogenesis and Evolution , 2010 .

[21]  R. Atlas,et al.  Hurricane forecasts with a global mesoscale‐resolving model: Preliminary results with Hurricane Katrina (2005) , 2006 .

[22]  Liguang Wu,et al.  Impact of Saharan air layer on hurricane peak intensity , 2007 .

[23]  Jason P. Dunion,et al.  A Reexamination of the Jordan Mean Tropical Sounding Based on Awareness of the Saharan Air Layer: Results from 2002 , 2008 .

[24]  E. Brin,et al.  AIRS impact on the analysis and forecast track of tropical cyclone Nargis in a global data assimilation and forecasting system , 2009 .

[25]  William M. Putman,et al.  Hurricane forecasting with the high‐resolution NASA finite volume general circulation model , 2005 .

[26]  R. Purser,et al.  Three-Dimensional Variational Analysis with Spatially Inhomogeneous Covariances , 2002 .

[27]  Thomas A. Jones,et al.  The environmental and inner-core conditions governing the intensity of Hurricane Erin (2001) , 2007 .

[28]  C. Velden,et al.  ARTICLES: The Impact of the Saharan Air Layer on Atlantic Tropical Cyclone Activity. , 2004 .

[29]  A. Heymsfield,et al.  Possible linkages between Saharan dust and tropical cyclone rain band invigoration in the eastern Atlantic during NAMMA‐06 , 2008 .

[30]  S. Moorthi,et al.  Relaxed Arakawa-Schubert - A parameterization of moist convection for general circulation models , 1992 .