Baijun Tian, Jet Propulsion Laboratory, M/S. 183-501, California Institute of Technology, 4800 Oak Grove Dr., Pasadena CA 91109. Email: baijun.tian@jpl.nasa.gov.

I. IntroductionThe Madden-Julian Oscillation (MJO) is the dominant form of intraseasonal variability in the tropical atmosphere, characterized by slowly eastward-propagating, large-scale oscillations in tropical deep convection and baroclinic wind field, especially during the boreal winter (November-April) over the warmest tropical waters in the equatorial Indian Ocean and western Pacific (Madden and Julian 1971; 1972; Lau and Waliser 2005; Zhang 2005). Since its discovery, the MJO has continued to be a topic of significant interest due to its extensive interactions with other components of the global climate system and the fact that it represents a connection between the better-understood weather and seasonal-to-interannual climate variations. To date, influences of the MJO on the physical components of the climate system have been well recognized, documented, and in same cases, also well understood (e.g., monsoon, ENSO, hurricane, and extratropical weather). However, the impacts of the MJO on the chemical component of the climate system have been realized only recently and have not been well documented and understood (e.g., Li et al. 2010; Tian et al. (e.g., Li et al. 2010; Tian et al. 2007; 2008; 2010; Weare 2010; Wong and Dessler 2007; Ziemke and Chandra 2003; Ziemke et al. 2007)2007; 2008; 2010; Weare 2010; Wong and Dessler 2007; Ziemke and Chandra 2003; Ziemke et al. 2007). In this poster, we highlight our ongoing exploratory activities on the chemical reach of the MJO using the modern atmospheric composition data from the A-Train satellite constellation.

References: • Tian, B., D. E. Waliser, E. J. Fetzer, and Y. L. Yung (2010), Vertical moist thermodynamic structure of the Madden-Julian Oscillation in Atmospheric Infrared Sounder retrievals: An update and a comparison to ECMWF interim reanalysis, Mon. Wea. Rev., 138, doi:10.1175/2010MWR3486.1, in press.• Tian, B., D. E. Waliser, R. A. Kahn, and S. Wong (2010), Modulation of Atlantic aerosols by the Madden-Julian Oscillation, J. Geophys. Res., under review. • Li, K.-F., B. Tian, D. E. Waliser, and Y. L. Yung, 2010: Tropical mid-tropospheric CO2 variability driven by the Madden-Julian Oscillation. Proc. Nat. Acad. Sci., 107, 19171-19175, doi:10.1073/pnas.1008222107.• Li, K.-F., B. Tian, D. E. Waliser, Y. L. Yung, M. J. Schwartz, J. L. Neu, and J. R. Worden (2010), Vertical structure of MJO-related subtropical ozone variations from MLS, TES and SHADOZ data, J. Geophys. Res., in prep.• Tian, B., and D. E. Waliser, 2010: Chemical and biological impacts. Chapter 13.4 of Intraseasonal Variability of the Atmosphere-Ocean System (2nd Edition), Edited by K.-M. Lau and D. E. Waliser, in press.

V. Summary The MJO is the dominant component of the intraseasonal (30–90 day) variability in the tropical atmosphere. The currently available A-Train atmospheric composition data provide us an unprecedented opportunity to study the MJO’s impacts on atmospheric composition. Our results indicate that the MJO can impact a number of important atmospheric constituents, such as H2O, aerosols, O3, and CO2.

Our results provide a better understanding of the intraseasonal variability of atmospheric composition and an important test for chemical transport models. Our results imply that some atmospheric constituents may be predictable with lead times of 2-4 weeks.

III. MJO Analysis MethodThe combined Empirical Orthogonal Function (EOF) analysis method as described in Wheeler and Hendon (2004) and Waliser et

al. (2009) was used. Briefly, the intraseasonal anomalies of the daily data were obtained by removing the annual cycle and filtering via a 30–90-day band pass filter. Then, average anomalies for each MJO phase of a composite MJO cycle were calculated. The MJO phase for each day was determined by the Real-time Multivariate MJO (RMM) index (a pair of principal component time series, called RMM1 and RMM2) developed by Wheeler and Hendon (2004). This RMM index is based on a pair of EOFs of the combined fields of near-equatorially averaged (15°S-15°N) 850-hPa zonal wind and 200-hPa zonal wind from NCEP/NCAR reanalysis, and satellite-observed outgoing longwave radiation (OLR) data. Only strong MJO events (RMM12 + RMM12>=1) in the boreal winter (November-April) were considered. Figure 1 shows the (RMM1, RMM2) phase space for all days in boreal winter from 2002 to 2009.

Exploring the Chemical Impacts of the Madden-Julian Oscillation using the A-Train DataBaijun Tian1, King-Fai Li2, Duane Waliser1, and Yuk Yung2

1. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA. 2. Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA.

National Aeronautics and Space Administration

Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, California

Figure 1: (RMM1, RMM2) phase space for all days in boreal winter from 2002 to 2009. Eight defined phases of the phase space are labeled to indicate the eastward propagation of the MJO in one MJO cycle. Also labeled are the approximate locations of the enhanced convective signal of the MJO for that location of the phase space, e.g., the ‘‘Indian Ocean’’ for phases 2 and 3.

Acknowledgment: This work was supported under the National Science Foundation (NSF) grant ATM-0840755 to University of California, Los Angeles (UCLA) and NSF grant ATM-0840787 to California Institute of Technology (Caltech) as well as the Atmospheric Infrared Sounder (AIRS) project at Jet Propulsion Laboratory (JPL). We thank many colleagues, particularly, Ralph Kahn, Eric Fetzer, Sun Wong, Michael Schwartz, John Worden, and Jessica Neu for valuable help.

II. A-Train Atmospheric Composition DataSensors Products Resolution (H, V) Height Range Record LengthAIRS/Aqua H2O profile

Temp profileO3

COCO2

Dust

45 km, 2 km45 km, 2 km45 km45 km90 km 45 km

>=300hPa>=10hPaTotal Col.Mid-TropMid-TropTotal Col.

09/2002-pres

CALIOP/CALIPSO Aerosol profile 40km, 120m/360m <20 km/20-30km 06/2006-pres

MODIS/Aqua MODIS/Terra

AOTAOT

10 km10 km

Total Col.Total Col.

07/2002-pres12/1999-pres

MLS/Aura H2O profileO3 profileCO profile

160 km, 3 km160 km, 3 km300 km, 4.5 km

<=316hPa <=215hPa <=316hPa

08/2004-pres

OMI/Aura Total O3

O3 profileAI/AOT

13 x 24 km13 x 48 km, 10 km13 x 24 km

Total Col.<60kmTotal Col.

08/2004-pres

TES/Aura O3 profileHDO

175 km, 8 km 700-10hPa>550hPa

08/2004-pres

MISR/Terra AOTAerosol particle properties

17.6 km Total Col. 12/1999-pres

Figure 2: Composite boreal winter 20–100-day CMAP precipitation (color) and NCEP/NCAR surface wind anomalies vectors) as a function of MJO phase. Zonal wind anomalies statistically significant at 99% based on Student’s t test are drawn. The reference vector in units of m/s is shown at the bottom right. The number of days used to generate the composite for each phase is shown to the right of each panel.

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