We make use of the Prolonged Remodeled Ocean Skin Heat (ERSST) investigation of Reynolds and you can Smith (1994), adaptation 3b (Smith et al

We make use of the Prolonged Remodeled Ocean Skin Heat (ERSST) investigation of Reynolds and you can Smith (1994), adaptation 3b (Smith et al

2008), that takes motorboat and buoy proportions and you can supplies a great gridded dataset at 2° resolution playing with an optimum interpolation method. We utilize the climatological analysis calculated anywhere between 1981 and 2010. Because the an excellent metric into the interhemispheric variation out of exotic SST, i estimate ?SST as spatially adjusted SST between your equator and 20°Letter without spatially adjusted SST between your couples hooking up equator and you may 20°S. step one

(iii) Atmospheric temperature transport over the equator

The atmospheric temperatures transport hails from the fresh Federal Centers to own Environmental Forecast (NCEP) four-times-each and every day reanalysis sphere (Kalnay et al. 1996) that have a beneficial (horizontal) spectral quality regarding T62 and 17 vertical levels. The brand new atmospheric temperatures transportation is actually calculated by the first controlling the fresh new atmospheric mass finances on the reanalysis analysis which have an excellent barotropic wind modification like in Trenberth (1997) and you may then figuring new meridional flux away from wet static energy 2 and you may vertically integrating. This method is employed to help you write month-to-month averaged atmospheric temperatures transportation away from 1981 to help you 2010 therefore the climatological mediocre over this period is used within this research.

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 regular amplitude and stage used in our data is laid out given that amplitude and you will phase of yearly harmonic.

2) Overall performance

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 seasonal period of tropical rain centroid against mix-equatorial atmospheric temperatures transportation. For every get across was based on this new monthly mediocre while the size of your own mix for each axis is short for the brand new 95% rely on interval assessed in the interannual variability. The fresh occupied container ‘s the yearly average. The dashed line ‘s the linear ideal complement on monthly averages. (bottom) Just like the at most useful, however for the fresh new tropical rain centroid vs the interhemispheric difference between exotic SST.

(top) Scatterplot of the regular duration regarding warm rain centroid versus mix-equatorial atmospheric heat transport. Per mix was based on the month-to-month mediocre therefore the length of your own mix on each axis means the new 95% depend on interval examined on the interannual variability. The brand new occupied package is the yearly mediocre. New dashed range is the linear most readily useful match for the monthly averages. (bottom) Once the within ideal, but for new tropical rain centroid vs the brand new interhemispheric difference in tropical SST.

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