Bellwork 4/13 Describe the weather associated with cyclones and anticyclones. What are the winds called between the Equatorial Low and the Subtropical High?

General atmospheric circulation Influence of continents Seasonal temperature differences disrupt the Global pressure patterns Global wind patterns Influence is most obvious in the Northern Hemisphere WHY??? _____________________

General atmospheric circulation Influence of continents Monsoon During warm months Warm, moist air flows onto land Winter months Dry air flows off the land

Average surface pressure and associated winds for July

Average surface pressure and associated winds for January

El Niño and La Niña El Niño A countercurrent that flows along the coasts of Ecuador and Peru Warm **Normally, the countercurrent lasts for a few weeks Every 2-7 years, the countercurrent is unusually strong…this is the El Nino affect

Normal conditions

El Niño

Strongest El Niño events on record occurred between 1982-83 and 1997-98 1997-98 event caused Heavy rains in Ecuador and Peru Ferocious storms in California Droughts in Australia Less intense monsoon season in eastern Asia *SO MANY MORE AFFECTS Ecological, economical, health-related, environmental, social, ect,

What causes El Nino? …we’re not entirely sure… Related to large-scale atmospheric circulation Pressure change between the eastern and western Pacific called the El Nino Southern Oscillation (ENSO) Changes in trade winds creates a major change in the equatorial current system, with warm water flowing eastward Effects are highly variable depending in part on the temperatures and size of the warm water pools

La Niña Opposite of El Niño Triggered by colder than average surface temperatures in the eastern Pacific Also not normal conditions…

La Niña Typical La Niña winter Blows colder than normal air over the Pacific Northwest and northern Great Plains while warming much of the rest of the United States Greater precipitation is expected in the Northwest Increased hurricane activity

Can we predict El Nino? We can try… Satellites Supercomputers Buoys Funding was cut in 2012

“The numbers don’t add up “The numbers don’t add up. When, in 2012, the US National Oceanic and Atmospheric Administration (NOAA) retired the Ka’imimoana, a former US Navy ship dedicated to maintaining an array of moored buoys that monitors the equatorial Pacific Ocean, administrators were able to chop roughly $6 million from the annual NOAA budget. In 2013, the agency says, it spent up to $3 million chartering boats for the same purpose. Those charters have failed to keep pace with the rigorous maintenance requirements, however, and the Tropical Atmosphere Ocean (TAO) array has partially collapsed as a result. The upshot is that, to save a few million dollars, NOAA has left the world partially blind to a phenomenon that can cause tens of billions of dollars in damage.” -From Nature