Chapter 4: Siberian high Flashcards Preview

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Flashcards in Chapter 4: Siberian high Deck (19)
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1

Siberian high: 

  • A massive collection of cold dry air that accumulates in the northeastern part of Eurasia from September until April.
  • Strongest semi-permanent high in the NH

2

Siberian high is centered on:

Lake Baikal 

3

Siberian high reaches its greatest size and strength in:

  • Winter when air temperature near the center is lower than -40 C
  • Pressure is above 1040 mb

4

Siberian high is responsible for:

  • The lowest temperature in NH -67.8 C
  • Highest pressure 1083.8 mb
  • Severe cold winter
    • Cold coastal winter in the Pacific Russia in relation to its:
      • Latitude
      • Proximity to the ocean
  • Attendant dry conditions with little snow
  • A few or no glacier across
    • Siberia
    • Magnolia
    • China 

5

What happens to Siberian high during summer?

  • Replaced by the Asiatic low
    • Indian thermal low

6

Siberian high affects: (how for it extends)

  • Its influence extends as far west as Italy
  • As far southeast as Malaysia
    • Critical to northeast monsoon
      • Responsible for formation of winter monsoon over south- west Asia

7

Strong Siberian high affects:

  • Bring cold weather into tropics
    • As far southeast as Philippines
    • As far east as eastern Canada
  • Block or reduce the size of lower pressure cells
  • Generate dry weather across Asian landscape
    • With exception of regions that receive orographic rainfall from winds it generates, such as:
      • Hokuriku
      • Caspian sea coast of Iran 

8

Siberian air characteristics:

  • Colder than arctic air
    • Because it forms over the cold tundra of Siberia
      • Does not radiate heat the same way the ice of the arctic does

9

Siberian high build up, peak and decay:

  • Build up at the end of august
  • Reaches its peak in winter
  • Remain strong until the end of April

10

Genesis of Siberian high:

  • Genesis at the end of the arctic summer
  • Caused by the convergence of summer air flows
    • Flows are cooled over interior northeast Asia as days shorten
  • Upper level het is transferred across northern Eurasia by:
    • Adiabatic cooling
    • Descending advection
    • In extreme cases creates cold domes that outbreak over warmer parts of east Asia

11

Warmer winters are caused by:

Weakening of the Siberian high

12

Warmer winters are noted in:

  • Almost all of inland extra tropical Asia
  • Most parts of Europe
  • Strongest relationship over
    • West Siberian plain
    • As far west as:
      • Hungary
    • As far southeast as:
      • Guangdong

13

Relationships between parameters and Siberian high:

  • Precipitation and Siberian high
  • Pressure system and Siberian high
  • Arctic oscillation and Siberian high

14

Precipitation and Siberian high:

  • Precipitation inversely related to the mean central pressure of the Siberian high over
    • Eastern Europe during boreal winter
    • Southern chine
  • Opposite correlation over
    • Coromandel coast
    • Sri Lanka 

15

Pressure systems and Siberian high:

Strength of Siberian high inversely related with the high pressure system over North Africa

16

Arctic oscillation and Siberian high:

Weaker Siberian high and arctic oscillation when the Antarctic oscillation (AAO) is stronger

17

Blocks:

  • Large scale patterns in atmospheric pressure field
  • Nearly stationary
    • Remain in place for several days or even weeks
      • Causing the areas affected to have the same weather for a long period of time
  • Effectively blocking
  • Redirecting migratory cyclones

18

Blocks are also known as:

  • Blocking high
  • Blocking anticyclones 

19

Blocks occur most frequently in:

Spring over the eastern pacific and Atlantic oceans.