首先让我们国家显而易见的原因:1。温暖的太平洋沿着帝汶海和昆士兰海岸有利于热带气旋的形成,以下两个url显示太平洋北部和东部海岸的澳大利亚引用的时期。海洋)http://earth.nullschool.net/ 2015/02/15/2100Z / /主/波/覆盖= sea_surface_temp /拼写= 136.27,-24.99,512 b) http://earth.nullschool.net/ 2015/02/20/2100Z /海洋/主/波/覆盖= sea_surface_temp /拼写= 136.27,-24.99,512热带气旋生成所需的阈值SST 26.5 C,这个研究[1]2所示。赤道波浪的作用在赤道热带cyclongenesis和在这种情况下,交互与季风槽波。过滤OLR的结果见下图显示了赤道罗斯贝波的存在在这些地区和蓝色阴影的存在表明消极OLR(增强对流)。![在这里输入图像描述][2]来源——http://monitor.cicsnc.org/mjo/current/[5]明确指出:“只是太模拟时没有ER波异常领域,《创世纪》太仍准恒定,TC没有发生。只有当ER波对TC《创世纪》开始的太。结果暗示ER wave-MT交互产生比将会产生更多的TCs如果没有这样的交互发生。”3. A question that can be raised is that we do know that presence of MJO also promotes tropical cyclongenesis as shown in this reference [6]. So how can does one state unequivocally that it is a Equatorial Rossby Wave and not the MJO's interaction with the MT that favours tropical cyclogenesis ? If we look at the strength of the MJO signal during and after the formation of TC Lam & Maria as shown in these set of images ![enter image description here][3] The amplitude of MJO signal is currently weak (less than 1 being present inside the circle) and is unlikely to be a significant contributor to the formation of tropical cyclones. This conclusion can be enhanced by looking at the filtered OLR contributions from MJO - ![enter image description here][4] The presence of positive OLR(in yellow over the Northern/Eastern part of Australia indicating suppressed convection. 4. Both the MJO as well as tropical waves favour the formation of twin cyclones as shown by references [7] and [8] **Update** In an earlier question that I had asked //www.hoelymoley.com/questions/2803/relation-between-direction-of-shear-and-cyclone-formation one can clearly see a working example of easterly shear favoring the formation of tropical cyclone. So easterly shear as shown in the map below is defined as the difference in the zonal winds at two different pressure levels (850 hPa and 200 hPa). Since by convention easterly winds are noted to be negative increasing positive values of shear is easterly shear(as one travels vertically) and the opposite is westerly shear. The following shear plot is a mean of several days and one can see the easterly shear over the Australian regions where the cyclone formation took place. $zonal\_shear = U_{850} - U_{200} $ The data is from NCAR NCEP reanalysis. [![enter image description here][5]][5] **References** [1] http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-10-05006.1 [5] http://journals.ametsoc.org/doi/abs/10.1175/2009MWR3115.1 [6] http://journals.ametsoc.org/doi/abs/10.1175/2009JAS3101.1 [7] http://journals.ametsoc.org/doi/abs/10.1175/2008MWR2541.1 [8] http://schubert.atmos.colostate.edu/publications/refereed/nietoetal1996_dynamical.pdf [1]: https://i.stack.imgur.com/RsjE6.gif [2]: http://i.stack.imgur.com/XU7JZ.gif [3]: http://i.stack.imgur.com/7qc3c.png [4]: http://i.stack.imgur.com/jyRP7.gif [5]: https://i.stack.imgur.com/ej2pR.png