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Californian drought: The processes and factors controlling the 2011-2016 drought and winter precipitation in California

Cederholm, Pontus LU (2016) In Student thesis series INES NGEK01 20161
Dept of Physical Geography and Ecosystem Science
Abstract
The factors and processes controlling winter precipitation in California and the 2011-2016 California drought have been examined in a literature study. The study showed that mid-latitude cyclones are the systems that generate winter precipitation in California. The location of high- and low-pressure systems in the northeast Pacific Ocean have a huge impact on the winter precipitation as they largely determine the direction of the jet stream, which transports the moisture-holding cyclones in over the North American west coast. Baroclinic instability and warm sea surface temperatures determines the intensity of cyclones. Orographic precipitation in mountainous regions is a significant mesoscale process, through which snowpack accumulates.... (More)
The factors and processes controlling winter precipitation in California and the 2011-2016 California drought have been examined in a literature study. The study showed that mid-latitude cyclones are the systems that generate winter precipitation in California. The location of high- and low-pressure systems in the northeast Pacific Ocean have a huge impact on the winter precipitation as they largely determine the direction of the jet stream, which transports the moisture-holding cyclones in over the North American west coast. Baroclinic instability and warm sea surface temperatures determines the intensity of cyclones. Orographic precipitation in mountainous regions is a significant mesoscale process, through which snowpack accumulates. Furthermore, the phases of the El Niño-Southern Oscillation and the Pacific decadal oscillation generally affects Californian winter precipitation to a degree. The El Niño-Southern Oscillation probably affected the drought, but the Pacific decadal oscillation influence on the drought is unclear. Global warming and climate change surely influence the aridity in California, but the drought was probably mainly caused by natural variability. (Less)
Abstract (Swedish)
Faktorerna och processerna som styr vinternederbörden i Kalifornien och torkan 2011-2016 har undersökts i en litteraturstudie. Resultaten visar främst att mellanbreddslågtryck i form av cykloner är de system som genererar vinternederbörd i Kalifornien. Hög- och lågtryckens läge i nordöstra Stilla Havet bestämmer jetströmmens gång som transporterar cyklonerna mot öster, in över den Nordamerikanska västkusten. Baroklinisk instabilitet och varma ytvatten i havet bestämmer cykloners intensitet. Orografisk nederbörd är en viktig process i delstatens bergsregioner. Genom det byggs snötäcken upp som lagrar vatten. El Niño-sydlig oscillation och Pacific decadal oscillation’s faser påverkar vinternederbörden i Kalifornien till en viss grad. El... (More)
Faktorerna och processerna som styr vinternederbörden i Kalifornien och torkan 2011-2016 har undersökts i en litteraturstudie. Resultaten visar främst att mellanbreddslågtryck i form av cykloner är de system som genererar vinternederbörd i Kalifornien. Hög- och lågtryckens läge i nordöstra Stilla Havet bestämmer jetströmmens gång som transporterar cyklonerna mot öster, in över den Nordamerikanska västkusten. Baroklinisk instabilitet och varma ytvatten i havet bestämmer cykloners intensitet. Orografisk nederbörd är en viktig process i delstatens bergsregioner. Genom det byggs snötäcken upp som lagrar vatten. El Niño-sydlig oscillation och Pacific decadal oscillation’s faser påverkar vinternederbörden i Kalifornien till en viss grad. El Niño-sydlig oscillation påverkade troligtvis torkan, men Pacific decadal oscillation’s inverkan på torkan är oklar. Den globala uppvärmningen och klimatförändringarna har troligtvis påverkat torkan, men den var sannolikt främst orsakad av naturlig variation. (Less)
Please use this url to cite or link to this publication:
author
Cederholm, Pontus LU
supervisor
organization
course
NGEK01 20161
year
type
M2 - Bachelor Degree
subject
keywords
winter precipitation, California, drought, mid-latitude cyclones, Physical Geography and Ecosystem Science
publication/series
Student thesis series INES
report number
376
language
English
id
8880163
date added to LUP
2016-06-14 17:01:16
date last changed
2016-06-14 17:01:16
@misc{8880163,
  abstract     = {The factors and processes controlling winter precipitation in California and the 2011-2016 California drought have been examined in a literature study. The study showed that mid-latitude cyclones are the systems that generate winter precipitation in California. The location of high- and low-pressure systems in the northeast Pacific Ocean have a huge impact on the winter precipitation as they largely determine the direction of the jet stream, which transports the moisture-holding cyclones in over the North American west coast. Baroclinic instability and warm sea surface temperatures determines the intensity of cyclones. Orographic precipitation in mountainous regions is a significant mesoscale process, through which snowpack accumulates. Furthermore, the phases of the El Niño-Southern Oscillation and the Pacific decadal oscillation generally affects Californian winter precipitation to a degree. The El Niño-Southern Oscillation probably affected the drought, but the Pacific decadal oscillation influence on the drought is unclear. Global warming and climate change surely influence the aridity in California, but the drought was probably mainly caused by natural variability.},
  author       = {Cederholm, Pontus},
  keyword      = {winter precipitation,California,drought,mid-latitude cyclones,Physical Geography and Ecosystem Science},
  language     = {eng},
  note         = {Student Paper},
  series       = {Student thesis series INES},
  title        = {Californian drought: The processes and factors controlling the 2011-2016 drought and winter precipitation in California},
  year         = {2016},
}