Observation of Moisture Tendencies Related to Shallow Convection

AbstractTropospheric moisture is a key factor controlling the global climate and its variability. For instance, moistening of the lower troposphere is necessary to trigger the convective phase of a Madden–Julian oscillation (MJO). However, the relative importance of the processes controlling this moistening has yet to be quantified. Among these processes, the importance of the moistening by shallow convection is still debated. The authors use high-frequency observations of humidity and convection from the Research Vessel (R/V) Mirai that was located in the Indian Ocean ITCZ during the Cooperative Indian Ocean Experiment on Intraseasonal Variability/Dynamics of the MJO (CINDY/DYNAMO) campaign. This study is an initial attempt to directly link shallow convection to moisture variations within the lowest 4 km of the atmosphere from the convective scale to the mesoscale. Within a few tens of minutes and near shallow convection occurrences, moisture anomalies of 0.25–0.5 g kg−1 that correspond to tendencies on ...

[1]  G. Kiladis,et al.  Observations of a Convectively Coupled Kelvin Wave in the Eastern Pacific ITCZ , 2002 .

[2]  Yonghua Chen,et al.  CORRIGENDUM of the MJO Transition from Shallow to Deep Convection in Cloudsat-Calipso Data and GISS GCM Simulations , 2012 .

[3]  Charles N. Long,et al.  Tracking Pulses of the Madden–Julian Oscillation , 2013 .

[4]  Richard H. Johnson,et al.  Multiscale variability of the atmospheric mixed layer over the Western Pacific warm pool , 2001 .

[5]  D. Randall,et al.  Observed Characteristics of the MJO Relative to Maximum Rainfall , 2007 .

[6]  Richard H. Johnson,et al.  Trimodal Characteristics of Tropical Convection , 1999 .

[7]  Peter V. Hobbs,et al.  Influences of Isolated Cumulus Clouds on the Humidity of Their Surroundings , 1996 .

[8]  Xiaoliang Song,et al.  Interaction of deep and shallow convection is key to Madden‐Julian Oscillation simulation , 2009 .

[9]  C. Jakob,et al.  The four cumulus cloud modes and their progression during rainfall events: A C‐band polarimetric radar perspective , 2013 .

[10]  Shuyi S. Chen,et al.  Equatorial Dry Air Intrusion and Related Synoptic Variability in MJO Initiation during DYNAMO , 2014 .

[11]  R. Houze,et al.  The precipitating cloud population of the Madden‐Julian Oscillation over the Indian and west Pacific Oceans , 2013 .

[12]  P. Zuidema,et al.  The mesoscale convection life cycle: building block or prototype for large-scale tropical waves? , 2006 .

[13]  J. W. Telford,et al.  The dynamical and liquid water structure of the small cumulus as determined from its environment , 1980 .

[14]  Tomohiro Nagai,et al.  Ice clouds and Asian dust studied with lidar measurements of particle extinction-to-backscatter ratio, particle depolarization, and water-vapor mixing ratio over Tsukuba. , 2003, Applied optics.

[15]  Weixin Xu,et al.  Convective Characteristics of the Madden-Julian Oscillation over the Central Indian Ocean Observed by Shipborne Radar during DYNAMO , 2013 .

[16]  C. Long,et al.  Quality-Controlled Upper-Air Sounding Dataset for DYNAMO/CINDY/AMIE: Development and Corrections , 2014 .

[17]  Forecast Skill of Madden-Julian Oscillation Events in a Global Nonhydrostatic Model during the CINDY2011/DYNAMO Observation Period , 2013 .

[18]  Katherine Thayer-Calder,et al.  The Role of Convective Moistening in the Madden–Julian Oscillation , 2009 .

[19]  J. Thepaut,et al.  The ERA‐Interim reanalysis: configuration and performance of the data assimilation system , 2011 .

[20]  T. Nagai,et al.  Comparisons of Raman Lidar Measurements of Tropospheric Water Vapor Profiles with Radiosondes, Hygrometers on the Meteorological Observation Tower, and GPS at Tsukuba, Japan , 2007 .

[21]  S. McFarlane,et al.  Constructing a Merged Cloud–Precipitation Radar Dataset for Tropical Convective Clouds during the DYNAMO/AMIE Experiment at Addu Atoll , 2014 .

[22]  R. Houze,et al.  Evolution of the Population of Precipitating Convective Systems over the Equatorial Indian Ocean in Active Phases of the Madden–Julian Oscillation , 2013 .

[23]  T. Zhou,et al.  Impacts of Shallow Convection on MJO Simulation: A Moist Static Energy and Moisture Budget Analysis , 2013 .

[24]  Carl J. Schreck,et al.  Large-Scale Atmospheric and Oceanic Conditions during the 2011-12 DYNAMO Field Campaign , 2013 .

[25]  M. Zelinka,et al.  Response of Humidity and Clouds to Tropical Deep Convection , 2009 .

[26]  Richard H. Johnson,et al.  Structure and Properties of Madden–Julian Oscillations Deduced from DYNAMO Sounding Arrays , 2013 .

[27]  Matthias Steiner,et al.  Climatological Characterization of Three-Dimensional Storm Structure from Operational Radar and Rain Gauge Data , 1995 .

[28]  C. Kummerow,et al.  Interactions between warm rain clouds and atmospheric preconditioning for deep convection in the tropics , 2011 .

[29]  Eric A. Smith,et al.  Physical Characterization of Tropical Oceanic Convection Observed in KWAJEX , 2005 .

[30]  B. Khouider,et al.  The Deepening of Tropical Convection by Congestus Preconditioning , 2010 .

[31]  Yukari N. Takayabu,et al.  Observation of a quasi-2-day wave during TOGA COARE , 1996 .

[32]  Y. Takayabu,et al.  The development of organized convection associated with the MJO during TOGA COARE IOP: Trimodal characteristics , 2004 .

[33]  An event-by-event assessment of tropical intraseasonal perturbations for general circulation models , 2013, Climate Dynamics.

[34]  Minghua Zhang,et al.  Tropical Cloud Heating Profiles: Analysis from KWAJEX , 2008 .

[35]  H. Masunaga.  A Satellite Study of Tropical Moist Convection and Environmental Variability: A Moisture and Thermal Budget Analysis , 2013 .

[36]  H. Kubota,et al.  Observed Evolution of Northward-Propagating Intraseasonal Variation over the Western Pacific: A Case Study in Boreal Early Summer , 2013 .

[37]  P. Webster,et al.  Transition between suppressed and active phases of intraseasonal oscillations in the Indo-Pacific warm pool , 2006 .

[38]  A. Genio,et al.  Factors Limiting Convective Cloud-Top Height at the ARM Nauru Island Climate Research Facility , 2006 .

[39]  M. Katsumata,et al.  Combined Use of TRMM/PR and Disdrometer Data to Correct Reflectivity of Ground-Based Radars , 2008 .

[40]  S. Esbensen,et al.  Heat and Moisture Budget Analyses Using BOMEX Data , 1974 .

[41]  S. Esbensen,et al.  Determination of Bulk Properties of Tropical Cloud Clusters from Large-Scale Heat and Moisture Budgets , 1973 .

[42]  Y. Takayabu,et al.  A Diagnostic Study on Interactions Between Atmospheric Thermodynamic Structure and Cumulus Convection over the Tropical Western Pacific Ocean and over the Indochina Peninsula , 2006 .

[43]  R. Rauber,et al.  A Revised Conceptual Model of the Tropical Marine Boundary Layer. Part III: Bragg Scattering Layer Statistical Properties , 2013 .

[44]  Kevin E. Trenberth,et al.  Climate Diagnostics from Global Analyses: Conservation of Mass in ECMWF Analyses , 1991 .

[45]  Christopher S. Bretherton,et al.  A Mass-Flux Scheme View of a High-Resolution Simulation of a Transition from Shallow to Deep Cumulus Convection , 2006 .

[46]  Richard H. Johnson,et al.  Diurnally Modulated Cumulus Moistening in the Preonset Stage of the Madden–Julian Oscillation during DYNAMO* , 2015 .

[47]  Brian E. Mapes,et al.  Clouds Associated with the Madden–Julian Oscillation: A New Perspective from CloudSat , 2011 .

[48]  David B. Parsons,et al.  Recovery Processes and Factors Limiting Cloud-Top Height following the Arrival of a Dry Intrusion Observed during TOGA COARE , 2002 .

[49]  R. Houze,et al.  The cloud population and onset of the Madden‐Julian Oscillation over the Indian Ocean during DYNAMO‐AMIE , 2013 .

[50]  Zhaohua Wu.  A Shallow CISK, Deep Equilibrium Mechanism for the Interaction between Large-Scale Convection and Large-Scale Circulations in the Tropics. , 2003 .

[51]  Chidong Zhang,et al.  Madden‐Julian Oscillation , 2005 .

[52]  Angela K. Rowe,et al.  Microphysical characteristics of MJO convection over the Indian Ocean during DYNAMO , 2014 .

[53]  J. David Neelin,et al.  Moisture Vertical Structure, Column Water Vapor, and Tropical Deep Convection , 2009 .

[54]  Bjorn Stevens,et al.  Preconditioning Deep Convection with Cumulus Congestus , 2013 .

[55]  B. Weare,et al.  The Onset of Convection in the Madden–Julian Oscillation , 2001 .

[56]  The event‐to‐event variability of the boreal winter MJO , 2012 .

[57]  H. Bellenger,et al.  Role of Diurnal Warm Layers in the Diurnal Cycle of Convection over the Tropical Indian Ocean during MISMO , 2010 .

[58]  B. Albrecht,et al.  On Trade Wind Cumulus Cold Pools , 2012 .

[59]  P. Zuidema.  The 600–800-mb Minimum in Tropical Cloudiness Observed during TOGA COARE , 1998 .