a case study of the 6 august 2012 962 hpa arctic ocean cyclone

A Case Study of the 6 August 2012 962 hPa Arctic Ocean Cyclone

Eric AdamchickUniversity at Albany, State University of New York

Albany, New York

NORTHERN HEMISPHERE SEA ICE AREA (MILLION SQUARE KM) FROM 1979 – 2012. IMAGE COURTESY OF THE POLAR RESEARCH GROUP, UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN.

Motivation

Motivation

• The 962 hPa Arctic Ocean cyclone occurred when the Arctic sea ice area was at a record low.

• If the loss of sea ice continues on the current trajectory what will be the effects on mid-latitude circulation patterns as well as local climates.

300-hPa Geopotential Height Anomalies. Image provided by the NOAA/ESRL Physical Sciences Division, Boulder Colorado from their Web site at http://www.cdc.noaa.gov/

850-hPa Temperature Anomalies. Image provided by the NOAA/ESRL Physical Sciences Division, Boulder Colorado from their Web site at http://www.cdc.noaa.gov/

300-hPa Vector Wind Anomalies. Image provided by the NOAA/ESRL Physical Sciences Division, Boulder Colorado from their Web site at http://www.cdc.noaa.gov/

Cyclogenesis and Development

• Warm air advection from antecedent cyclone shifted the thermal gradient poleward

• Cyclogenesis of 962 hPa Arctic Ocean Cyclone

• Phasing of the cyclones’ vorticity and subsequent rapid deepening

120803/0600 500-hPa Geopotential Height (dam), QG Height Tendency 700-300 hPa Differential Thermal Advection [shaded (10-13 s-3)], NCEP .5o GFS Analysis Data.

120803/1800 300-hPa Geopotential Height (dam), Isotachs [shaded (m s-1)], and Sea Level Pressure (hPa), NCEP .5o GFS Analysis Data.

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120803/1800 500-hPa Geopotential Height (dam), Absolute Vorticity [shaded (10-5 s-1)], QG Height Tendency Absolute Vorticity Advection [cool shading (10-13 s-3)], NCEP .5o GFS Analysis Data.

120804/1800 500-hPa Geopotential Height (dam), Absolute Vorticity [shaded (10-5 s-1)], QG Height Tendency Absolute Vorticity Advection [shaded (10-13 s-3)], NCEP .5o GFS Analysis Data.


L1L2


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Summary• Warm air advection from the antecedent storm strengthened and

shifted the anomalous baroclinic zone poleward.

• Cyclogenesis occurred in a coupled jet environment collocated with the anomalous baroclinic zone.

• Rapid intensification began when the vorticity from both storms phased and continued in the poleward exit region of a 60 m s-1 jet streak.

• The 962 hPa Arctic Ocean cyclone occurred during a record minimum of Northern Hemispheric sea ice area.

Future Research

• Will storm frequency and strength increase in the absence of sea ice?

• What will be the effects on global circulation patterns?

• Will major storm tracks shift poleward?

• What effects will this have on local climates?

Acknowledgements

• Dr. Kristen Corbosiero• Dr. Paul Roundy• Dr. Lance Bosart• Ross Lazear

a case study of the 6 august 2012 962 hpa arctic ocean cyclone

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