Death comes to us all. Life's but a walking shadow | There is a lot of details to plow thru but suffice to say that some of the very worse crop years have occured as a strong El Nino transitioned back to a strong La Nina. There are other shorter period cycles like the Madden-Julian occillation which is a 40-60 day cycle that circles the earth that modify & attenuate the effects but it's all in the timing. The Madden-Julian cycle is a convection cycle, more convection equals more precipitation, less convection equals less precipitation.
Think of it this way. Throw a heavy knife into the air with a lot of spin. Now, try to catch the knife on the way back down. It is possible to catch the knife by the handle but it depends on how the blade is oriented. The higher you throw the knife the faster it will be falling when you try to catch it.
To give you an example, the dry period in Nov. & Dec that recently seriously threaten the soybean crop in central Brazil. As bad as it was a high convection phase of the Madden-Julian occillation occured over Brazil just at the right time to bring some precipitation. Not anywhere near as much as normal but enough for them to squeak by. Now the typical El nino pattern is returning, heavy rain in southern South America, dry in north central Brazil.
Well Ben, the knife has been thrown up really high this time. It's up to you to catch it. |
El Niño/la Niña course
