2008), which will take boat and you may buoy dimensions and you can produces an effective gridded dataset at 2° solution playing with a maximum interpolation means. I make use of the climatological investigation computed anywhere between 1981 and 2010. Just like the good metric on the interhemispheric distinction from warm SST, i determine ?SST since spatially weighted SST between the equator and 20°Letter without having the spatially adjusted SST within equator and you will 20°S. step 1
(iii) Atmospheric heat transport along side equator
Brand new atmospheric temperature transport comes from the fresh new National Stores getting Environmental Prediction (NCEP) four-times-every day reanalysis sphere (Kalnay mais aussi al. 1996) which have an effective (horizontal) spectral quality off T62 and you will 17 straight account. The brand new atmospheric temperature transportation try determined by the first balancing the fresh new atmospheric mass finances in the reanalysis study that have a beneficial barotropic snap modification as in Trenberth (1997) and you may then figuring new meridional flux from moist static opportunity 2 and you will vertically partnering. This process can be used so you’re able to write monthly averaged atmospheric temperatures transport out-of 1981 so you can 2010 together with climatological mediocre more than this era can be used contained in this study.
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).
Brand new regular amplitude and you will stage utilized in our very own studies are defined given that amplitude and you will phase of the annual harmonic.
2) Performance
A scatterplot of the monthly average PCent 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 best sex hookup apps 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 PCent 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 seasonal years from warm rain centroid compared to cross-equatorial atmospheric temperatures transport. For each get across was centered on the brand new monthly mediocre and the duration of your mix on every axis is short for the 95% confidence period reviewed on the interannual variability. This new filled package is the yearly mediocre. This new dashed line ‘s the linear better match to the month-to-month averages. (bottom) Since the within greatest, however for the newest exotic rain centroid compared to new interhemispheric difference between exotic SST.
(top) Scatterplot of your own seasonal period out of warm rain centroid against mix-equatorial atmospheric temperature transportation. Per mix is according to the latest monthly mediocre additionally the length of one’s mix for each axis is short for the fresh new 95% trust period examined about interannual variability. The fresh new filled field is the yearly mediocre. The newest dashed line ‘s the linear ideal fit into the monthly averages. (bottom) Because the within ideal, but also for the tropical precipitation centroid vs the brand new interhemispheric difference between exotic SST.