development of diagnostic enzyme assay to detect leuser virus
Dissertation Defense: Zachary Labe
1. The effects of Arctic sea-ice
thickness loss and stratospheric
variability on mid-latitude
cold spells
Zachary Labe
University of California, Irvine
22 May 2020
Ph.D. Defense
Chair
Dr. Gudrun Magnusdottir
Committee
Dr. Hal S. Stern
Dr. Michael S. Pritchard
31. MOTIVATION
ARCTIC SEA ICE
MID-LATITUDE
WEATHER
1. Labe, Z.M., G. Magnusdottir, and H.S. Stern (2018), Variability of Arctic sea ice thickness using
PIOMAS and the CESM Large Ensemble, Journal of Climate
2. Labe, Z.M., Y. Peings, and G. Magnusdottir (2018), Contributions of ice thickness to the
atmospheric response from projected Arctic sea ice loss, Geophysical Research Letters
3. Labe, Z.M., Y. Peings, and G. Magnusdottir (2019). The effect of QBO phase on the atmospheric
response to projected Arctic sea ice loss in early winter, Geophysical Research Letters
32. 1) Explore internal and forced
variability of Arctic sea-ice
thickness (SIT) and sea-ice volume
2) Isolate the role of SIT on the large-
scale atmosphere (troposphere-
stratosphere coupling)
3) Assess the effect of QBO phase
on atmospheric response to sea ice
• Satellites
• PIOMAS
• LENS
• Exploratory
data analysis
• Sea-ice
thickness
perturbation
experiments
• QBO
perturbation
experiments
KEY OBJECTIVES
33. [ SIT ]
Sea Ice
Thickness
Depth between sea
surface and ice/snow
layer
[ SIC ]
Sea Ice
Concentration
Fraction (%) of seawater
covered by ice
Snow
Ice
[ SIE ]
Sea Ice
Extent
Area of seawater
covered by any
amount of ice (>15%)
34. [ SIT ]
Sea Ice
Thickness
Depth between sea
surface and ice/snow
layer
[ SIC ]
Sea Ice
Concentration
Fraction (%) of seawater
covered by ice
Snow
Ice
[ SIE ]
Sea Ice
Extent
Area of seawater
covered by any
amount of ice (>15%)
35. [ SIT ]
Sea Ice
Thickness
Depth between sea
surface and ice/snow
layer
[ SIC ]
Sea Ice
Concentration
Fraction (%) of seawater
covered by ice
Snow
Ice
[ SIE ]
Sea Ice
Extent
Area of seawater
covered by any
amount of ice (>15%)
36. 1. Compare satellite, submarine, and simulated (“reanalysis”)
sea-ice thickness products
2. Analyze changes in the variability of sea-ice thickness using
the reanalysis product and CESM Large Ensemble Project
3. Quantify future projections (21st century) of Arctic sea-ice
thickness and volume using a regional approach
Explore changes in the temporal and spatial
variability of Arctic sea-ice thickness over the
satellite-era and 21st century
53. 1) Explore internal and forced
variability of Arctic sea-ice
thickness (SIT) and sea ice volume
2) Isolate the role of SIT on the large-
scale atmosphere (troposphere-
stratosphere coupling)
3) Assess the effect of QBO phase
on atmospheric response to sea ice
• Satellites
• PIOMAS
• LENS
• Exploratory
data analysis
• Sea-ice
thickness
perturbation
experiments
• QBO
perturbation
experiments
KEY OBJECTIVES
55. R/V Lance – Greenland Sea – May 2017
Turbulent heat fluxes
[ SIC ]
56. R/V Lance – Greenland Sea – May 2017
Turbulent heat fluxes
[ SIC + SIT ]
57. 1. Analyze tropospheric and stratospheric response to sea-ice
thickness loss in the late 21st century
2. Compare relative contributions of sea-ice concentration
versus sea-ice thickness to total atmospheric response
3. Address role of sea-ice thickness on the contrasting
stratospheric response to regional sea-ice anomalies
Isolate the effect of sea-ice thickness on the
large-scale atmospheric response to total
Arctic sea-ice decline
58. WACCM4
Whole Atmosphere
Community Climate
Model version 4 –
Specified Chemistry
“high top”
chemistry-climate
atmosphere
model
Physical
parameterizations
from CAM4
• 66 vertical levels – extending to
5 x 10-6 hPa (140 km)
• 1.9° latitude x 2.5° longitude
• QBO prescribed from
radiosonde observations
• Improved representation of
sudden stratospheric warming
(SSW) events
• fixed radiative forcings from
year 2000
59. 𝚫SIT = FIT – HIT
𝚫SIC = FIC – HIC
𝚫NET = FICT – HIT• Loss of sea-ice
thickness and
concentration
• Loss of sea-ice
thickness
• Loss of sea-ice
concentration
62. Future Arctic
How does sea-ice thickness
decline influence the large-
scale atmospheric response?
Significant thermodynamic
response over Arctic Ocean
Poleward weakening of jet
LABE ET AL. 2018, GRL
63. Future Arctic
Significant thermodynamic
response over Arctic Ocean
Poleward weakening of jet
LABE ET AL. 2018, GRL
How does sea-ice thickness
decline influence the large-
scale atmospheric response?
69. 1) Explore internal and forced
variability of Arctic sea-ice
thickness (SIT) and sea ice volume
2) Isolate the role of SIT on the large-
scale atmosphere (troposphere-
stratosphere coupling)
3) Assess the effect of QBO phase on
atmospheric response to sea ice
KEY OBJECTIVES
• Satellites
• PIOMAS
• LENS
• Exploratory
data analysis
• Sea-ice
thickness
perturbation
experiments
• QBO
perturbation
experiments
70. Assess the role of the Quasi-biennial
Oscillation (QBO) on the atmospheric
response to Arctic sea-ice loss
Composite response by
QBO phase (~67 years)
Modulation
by QBO
Sea ice
experiments
72. Assess the role of the Quasi-biennial
Oscillation (QBO) on the atmospheric
response to Arctic sea-ice loss
Composite response by
QBO phase (~67 years)
Modulation
by QBO
Sea ice
experiments
Future (2051-2080)
Historical (1975-2005)
73. Assess the role of the Quasi-biennial
Oscillation (QBO) on the atmospheric
response to Arctic sea-ice loss
Composite response by
QBO phase (~67 years)
Modulation
by QBO
Sea ice
experiments
Future (2051-2080)
Historical (1975-2005)
74. Assess the role of the Quasi-biennial
Oscillation (QBO) on the atmospheric
response to Arctic sea-ice loss
Modulation
by QBO
Sea ice
experiments
Composite response by
QBO phase (~67 years)
Easterly (QBO-E)
Westerly (QBO-W)
75. Assess the role of the Quasi-biennial
Oscillation (QBO) on the atmospheric
response to Arctic sea-ice loss
Modulation
by QBO
Sea ice
experiments
Composite response by
QBO phase (~67 years)
Easterly (QBO-E)
Westerly (QBO-W)
76. Assess the role of the Quasi-biennial
Oscillation (QBO) on the atmospheric
response to Arctic sea-ice loss
Sea ice
experiments
Composite response by
QBO phase (~67 years)
Modulation
by QBO
Surface (thermodynamic)
Troposphere/Stratosphere
84. MOTIVATION
ARCTIC SEA ICE
MID-LATITUDE
WEATHER
Sea-ice thickness variability is important for reinforcing the
atmospheric response
Strength of Siberian High closely related to Eurasia cold spells
QBO can modulate teleconnections due to Arctic sea-ice loss
85. MOTIVATION
ARCTIC SEA ICE
MID-LATITUDE
WEATHER
Sea-ice thickness variability is important for reinforcing the
atmospheric response
Strength of Siberian High closely related to Eurasia cold spells
QBO can modulate teleconnections due to Arctic sea-ice loss
86. MOTIVATION
ARCTIC SEA ICE
MID-LATITUDE
WEATHER
Sea-ice thickness variability is important for reinforcing the
atmospheric response
Strength of Siberian High closely related to Eurasia cold spells
QBO can modulate teleconnections due to Arctic sea-ice loss
87. WHAT IS THE EFFECT OF
SEA-ICE LOSS
RELATIVE TO
ARCTIC AMPLIFICATION?
88. WHAT IS THE EFFECT OF
SEA-ICE LOSS
RELATIVE TO
ARCTIC AMPLIFICATION?
Labe, Z.M., Y. Peings, and G. Magnusdottir (2020), Warm Arctic, cold
Siberia pattern: role of full Arctic amplification versus sea ice loss alone.
(in review)
106. So many thanks:
Magnusdottir Research Group
Department of Earth System Science
1st Year Cohort/Friends/Family
--------------------------
DOE/NOAA/NSF
Data Science Initiative & MAPS
Jenkins Family