2008), which will take boat and you will buoy measurements and supplies good gridded dataset in the dos° quality using an optimum interpolation approach. We make use of the climatological investigation calculated between 1981 and you will 2010. While the an effective metric towards interhemispheric improvement away from warm SST, i estimate ?SST given that spatially adjusted SST amongst the equator and you may 20°Letter without any spatially adjusted SST between your equator and you can 20°S. step 1
(iii) Atmospheric heat transport across the equator
The fresh new atmospheric temperatures transport is derived from the new National Facilities for Environmental Prediction (NCEP) four-times-day-after-day reanalysis sphere (Kalnay et al. 1996) that have a (horizontal) spectral solution from T62 and you can 17 vertical membership. The newest atmospheric heat transport try calculated of the very first balancing the fresh new atmospheric mass finances from the reanalysis studies that have an effective barotropic cinch modification such as Trenberth (1997) and you can then calculating the new meridional flux of wet fixed opportunity 2 and you can vertically partnering. This procedure is employed so you can compose month-to-month averaged atmospheric temperature transport off 1981 to 2010 and also the climatological mediocre over this era is employed contained in this investigation.
We use longwave and shortwave radiative fluxes from the Clouds and Earth’s Radiant Energy System (CERES) experiment (Wielicki et al. 1996) to calculate ?SWABS? and ?OLR?. All calculations are performed separately for each of the four CERES instruments (FM1 and FM2 on Terra from 2000 to 2005 and FM3 and FM4 on Aqua from 2002 to 2005). 
We then average the results over the four instruments. The quantity ?STORatmos? is calculated as the finite difference of the vertically integrated temperature and specific humidity from the NCEP reanalysis climatology. As in Donohoe and Battisti (2013), ?SHF? is calculated as the residual of radiative heating, atmospheric storage, and the atmospheric heat transport divergence (from NCEP reanalysis).
The fresh new seasonal amplitude and you can phase used in all of our analysis was laid out as amplitude and you will phase of the yearly harmonic.
2) Abilities
A scatterplot of the monthly average PPenny versus AHTEQ and ?SST is shown in Fig. 3. The precipitation centroid varies from 5.3°S in February to 7.2°N in August and has an annual average of 1.65°N. This seasonal cycle of ITCZ location is slightly damped (equatorward) of other common metrics of ITCZ location (e.g., the latitude of maximum zonal mean precipitation, Xian and Miller 2008). It can be seen that PPenny spends four months of the year in the Southern Hemisphere during the austral summer as the most intense precipitation is found in the South Pacific convergence zone at this time of year (not shown) and the zonal mean precipitation maximum moves to southern latitudes. We note that although the marine ITCZ defined in the eastern Pacific and Atlantic by Waliser and Gautier (1993) never moves south of the equator, the global ITCZ defined in the same study does move into the Southern Hemisphere and agrees very well with our precipitation centroid.
(top) Scatterplot of one’s regular duration out-of warm rain centroid versus cross-equatorial atmospheric heat transport. For each and every cross was based on the newest month-to-month average and size of your own mix on every axis is short for the newest 95% confidence period analyzed throughout the interannual variability. The fresh occupied package ‘s the annual mediocre. The fresh new dashed line ‘s the linear greatest fit with the monthly averages. (bottom) Since the during the most readily useful, but for the tropical rain centroid versus new interhemispheric difference between tropical SST.
(top) Scatterplot of regular duration away from exotic precipitation centroid vs cross-equatorial atmospheric heat transportation. For every single get across was based on the new month-to-month average and the length of your own mix on each axis means the fresh new 95% believe interval analyzed regarding the interannual variability. The latest filled package is the yearly mediocre. The fresh new dashed range is the linear better complement to your month-to-month averages. (bottom) Because within most useful, however for the new warm precipitation centroid against the brand new interhemispheric difference between warm SST.
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