Snowball oceanography. What is Snowball Earth? Most extreme climate event in Earth history. Characteristics: Occurred at least twice between 750-635 Ma.

Slides:

Advertisements

Similar presentations

Global climate responses to perturbations in Antarctic Intermediate Water Jennifer Graham Prof K. Heywood, Prof. D. Stevens, Dr Z. Wang (BAS)

Advertisements

1 Dynamical Polar Warming Amplification and a New Climate Feedback Analysis Framework Ming Cai Florida State University Tallahassee, FL 32306

Section 2: The Planetary Boundary Layer

Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline.

Modeling the MOC Ronald J Stouffer Geophysical Fluid Dynamics Laboratory NOAA The views described here are solely those of the presenter and not of GFDL/NOAA/DOC.

GEOS 112 Lecture Topics 4/28/03 Read Chapter 12 (Glaciers) Final Exam – Monday, May 5 1:00pm 1.Types of Glaciers; 2.Glacier Formation, Mass Balance, and.

Thermohaline circulation ●The concept of meridional overturning ●Deep water formation and property Antarctic Bottom Water North Atlantic Deep Water Antarctic.

Oceanography Chapter Heating of Earth’s surface and atmosphere by the sun drives convection within the atmosphere and oceans, producing winds and.

Dynamics V: response of the ocean to wind (Langmuir circulation, mixed layer, Ekman layer) L. Talley Fall, 2014 Surface mixed layer - Langmuir circulation.

Reading: Chapter 4 Lecture 25. Snowball Earth vs. Slushball Earth..

Climate modeling Current state of climate knowledge – What does the historical data (temperature, CO 2, etc) tell us – What are trends in the current observational.

Steady State General Ocean Circulation “steady state” means: constant in time, no accelerations or Sum of all forces = 0 Outline:1. Ekman dynamics (Coriolis~Friction)

Outline Further Reading: Detailed Notes Posted on Class Web Sites Natural Environments: The Atmosphere GG 101 – Spring 2005 Boston University Myneni L31:

Bow Echo Sensitivity to Ambient Moisture and Cold Pool Strength Richard P. James, Paul M. Markowski, and J. Michael Fritsch, 2006: Mon. Wea. Rev., 134,

D A C B z = 20m z=4m Homework Problem A cylindrical vessel of height H = 20 m is filled with water of density to a height of 4m. What is the pressure at:

The General Circulation of the Atmosphere Tapio Schneider.

=(S,,0); 4=(S,,4000).

Lecture 7: The Oceans (1) EarthsClimate_Web_Chapter.pdfEarthsClimate_Web_Chapter.pdf, p

EVAT 554 OCEAN-ATMOSPHERE DYNAMICS THERMOHALINE CIRCULATION (CONTINUED) LECTURE 20.

Goals for this section 1.EXPLAIN the feedback mechanism believed to have maintained Earth's average temperature within the range of liquid water over 100s.

© Imperial College LondonPage 1 Solar Influence on Stratosphere-Troposphere Dynamical Coupling Isla Simpson, Joanna D. Haigh, Space and Atmospheric Physics,

On the Mechanisms of the Late 20 th century sea-surface temperature trends in the Southern Ocean Sergey Kravtsov University of Wisconsin-Milwaukee Department.

Long-Term Climate Cycles &the Proterozoic Glaciations(Snowball Earth) Assigned Reading: Stanley, pp , Hoffman & Schrag (2002) Terra Nova,

Lori Sentman December 5, Shoaling of the Isthmus of Panama 1 (Haug et al. 2004) Pacific -> Atlantic flow through the CAS Similar salinities between.

Evaporative heat flux (Q e ) 51% of the heat input into the ocean is used for evaporation. Evaporation starts when the air over the ocean is unsaturated.

1 Introduction to Isentropic Coordinates: a new view of mean meridional & eddy circulations Cristiana Stan School and Conference on “the General Circulation.

Snow, Ice & Polar Environmental Change for K-12 Classrooms

1.Introduction 2.Description of model 3.Experimental design 4.Ocean ciruculation on an aquaplanet represented in the model depth latitude depth latitude.

Snowball Earth Hoffman et al. Science Evidence.

Rossby Wave Two-layer model with rigid lid η=0, p s ≠0 The pressures for the upper and lower layers are The perturbations are 

Projecting changes in climate and sea level Thomas Stocker Climate and Environmental Physics, Physics Institute, University of Bern Jonathan Gregory Walker.

2. Climate: “average” weather conditions, but the average doesn’t stay steady. I.e. Ice ages, El Niño, etc. 1. Weather: state of the atmosphere at a given.

Lecture 5 The Climate System and the Biosphere. One significant way the ocean can influence climate is through formation of sea ice. Sea ice is much more.

Extreme Climate Change: The late Neoproterozoic “Snowball Earth”

EVAT 554 OCEAN-ATMOSPHERE DYNAMICS FILTERING OF EQUATIONS FOR ATMOSPHERE (CONT) LECTURE 6 (Reference: Peixoto & Oort, Chapter 3)

Antarctic Climate Response to Ozone Depletion in a Fine Resolution Ocean Climate Mode by Cecilia Bitz 1 and Lorenzo Polvani 2 1 Atmospheric Sciences, University.

Late Proterozoic Snowball Earth Brian Morgan Colby College December 3, 2012.

KoreaCAM-EULAG February 2008 Implementation of a Non-Hydrostatic, Adaptive-Grid Dynamics Core in the NCAR Community Atmospheric Model William J. Gutowski,

Geothermal heating : the unsung diva of abyssal dynamics Julien Emile-Geay Lamont-Doherty Earth Observatory, Palisades, NY, USA Gurvan Madec LODYC, Paris,

The Faint Young Sun Problem. Systems Notation = system component = positive coupling = negative coupling.

CO 2 and Climate Change. Lisiecki & Raymo,

Current Weather Introduction to Air-Sea interactions Ekman Transport Sub-tropical and sub-polar gyres Upwelling and downwelling Return Exam I For Next.

Modeling of Subaqueous Melting of Greenland Tidewater glaciers

Typical Distributions of Water Characteristics in the Oceans.

Regional Oceanography II OEAS 604 Lecture Outline 1)Pacific Ocean circulation 2)Antarctic circulation 3)Climate cycles 4)Atmosphere-ocean coupling Chapters.

1 Marginal Thermobaric Stability in the Weddell Sea Miles McPhee McPhee Research Company.

Class 8. Oceans Figure: Ocean Depth (mean = 3.7 km)

For the last 60 My, the climate has been ‘cooling down’, and becoming more and more variable over short time scales. (note log time scale).

Density structure of the Ocean - Distribution of temperature and salinity in the ocean.

Oceans and anthropogenic CO 2 By Monika Kopacz EPS 131.

Hydrosphere. The hydrosphere contains all the water found on our planet. Water found on the surface of our planet includes the ocean as well as water.

Observed and projected changes to the ocean, Part 1 Climate models, pitfalls and historical observations (Chapter 3, Ganachaud et al., 2012) Alex Sen Gupta.

Salinity and Density Differences VERTICAL STRUCTURE, THERMOHALINE CIRCULATION & WATER MASSES.

On the effect of the Greenland Scotland Ridge on the dense water formation in the Nordic Seas Dorotea Iovino NoClim/ProClim meeting 4-6 September 2006.

UNIT 1: Weather Dynamics Chapter 1: Inquiring about Weather The Causes of Weather Chapter 2: Weather Forecasting.

Atmospheric and Oceanic General Circulation Dr. John Krasting NOAA/GFDL – Princeton, NJ Rutgers Physical Climatology October 18,

CoriolisPressure Gradient x z CURRENTS WITH FRICTION Nansen’s qualitative argument on effects of friction CoriolisPressure Gradient x y CoriolisPressure.

Coastal Winds + Coriolis Effect = Upwelling Southern hemisphere: water moves to the left of wind El niño - shutdown of upwelling.

Ocean Currents. Mass movement or flow of ocean water Mass movement or flow of ocean water River within the ocean River within the ocean Two types Two.

A snowball Earth versus a slushball Earth: Results from Neoproterozoic climate modeling sensitivity experiments Micheels and Montenari (2008) By: Madeline.

Our water planet and our water hemisphere

EVAT 554 OCEAN-ATMOSPHERE DYNAMICS

Snowball Earth vs. Slushball Earth..

What Causes Ice Ages?

Leah Birch Timothy Cronin, and Eli Tziperman

EVAT 554 OCEAN-ATMOSPHERE DYNAMICS

Coupled atmosphere-ocean simulation on hurricane forecast

For environment: Then For small δz (i.e., (δz)2 and higher terms are negligible),

EOSC 112: THE FLUID EARTH OCEAN STRUCTURE

Modes of tropical precipitation changes (variability)

Presentation transcript:

Snowball oceanography

What is Snowball Earth? Most extreme climate event in Earth history. Characteristics: Occurred at least twice between Ma. Occurred at least twice between Ma. Global (or almost global) ice coverage. Global (or almost global) ice coverage. More than 1 km thick sea-glacier. More than 1 km thick sea-glacier. Mean global temperature: -44 o C. Mean global temperature: -44 o C. (1992)

How do we know about snowball? Figs from Hoffman & Schrag 2002 For more: Glacial deposits: Dropstone Glacial deposits at low paleo-latitude Evidence for Snowball: 1)Low latitudes glacial deposit. 2)Open water deposit. 3)Carbon isotope ratio. 4)Banded iron formation. 5)Cap carbonate rocks. …

Goal Improve understanding of the climate system. Improve understanding of the climate system. Improve climate models. Improve climate models. Photosynthetic life under the thick ice? Photosynthetic life under the thick ice? What do we do? We use and coupled the following models: Ice-flow model of Tziperman et al. (2012). Ice-flow model of Tziperman et al. (2012). Oceanic MITgcm using shelf-ice package and bottom geothermal heating. Idealized BC. Oceanic MITgcm using shelf-ice package and bottom geothermal heating. Idealized BC. Ice-flow and ocean models exchange information every few hundred years (300 yr). Ice-flow and ocean models exchange information every few hundred years (300 yr). Motivation Study ocean circulation under global ice-cover.

Models’ coupling (i)Lat./depth ocean (1D ice): 1 o resolution (82 o S to 82 o N) with 32 levels with 10 m resolution in vicinity of ice. Ocean depth of 2 km plus 1 km ice. (ii)Eddy resolving (1/8 o ), equatorial sector (0 o —45 o E and 10 o S—10 o N) (iii)3D ocean (2D ice), 2 o resolution globally. 73 levels. q—melting/freezing rate T f —freezing temperature h—sea-glacier depth T(z=0)—ice temp. at z=0.

Results: 2D ocean, 1D ice

Summary of the 2D results (i) Strong equatorial currents. (ii) Enhanced equatorial concentrated meridional overturning circulation (MOC) cell. (iii) Anti-symmetric and broad zonal vel. (u). (iv) Symmetric & confined meridional vel. (v). (v) u, v change sign with depth. w and MOC maximal at mid-depth. (vi) No MOC above above the maximum heating. (vii) Difference in temperature of 0.2 o C. (viii) Difference in salinity of 0.5 ppt. We wish to understand why: (i)—(vi). (i)—(vi). Study a simplified set of equations (i) Strong equatorial currents. (ii) Enhanced equatorial concentrated meridional overturning circulation (MOC) cell. (iii) Anti-symmetric and broad zonal vel. (u). (iv) Symmetric & confined meridional vel. (v). (v) u, v change sign with depth. w and MOC maximal at mid-depth. (vi) No MOC above above the maximum heating. (vii) Difference in temperature of 0.2 o C. (viii) Difference in salinity of 0.5 ppt.

Model Assumptions: (i) 2D (latitude-depth) ( (ii) constant ice depth, (iii) steady state (, (iv) β-plane. Assumptions: (i) 2D (latitude-depth) (∂/∂x =0), (ii) constant ice depth, (iii) steady state (∂/∂t =0), (iv) β-plane. × ××× × × Neglect terms based on “scaling” or numeric.

  Equator: Pressure gradient is balanced by viscosity. Off-equator: “geostrophy”. z=0 at mid depth. (i) Strong equatorial currents. (ii) Enhanced equatorial concentrated meridional overturning circulation (MOC) cell. (iii) Anti-symmetric and broad zonal vel. (u). (iv) Symmetric & confined meridional vel. (v). (v) u, v change sign with depth. w and MOC maximal at mid-depth. (vi) No MOC above above the maximum heating.

  Equator: Pressure gradient is balanced by viscosity. Off-equator: “geostrophy”. z=0 at mid depth. (i) Strong equatorial currents. (ii) Enhanced equatorial concentrated meridional overturning circulation (MOC) cell. (iii) Anti-symmetric and broad zonal vel. (u). (iv) Symmetric & confined meridional vel. (v). (v) u, v change sign with depth. w and MOC maximal at mid-depth. (vi) No MOC above above the maximum heating.

  Equator: Pressure gradient is balanced by viscosity. Off-equator: “geostrophy”. z=0 at mid depth. (i) Strong equatorial currents. (ii) Enhanced equatorial concentrated meridional overturning circulation (MOC) cell. (iii) Anti-symmetric and broad zonal vel. (u). (iv) Symmetric & confined meridional vel. (v). (v) u, v change sign with depth. w and MOC maximal at mid-depth. (vi) No MOC above above the maximum heating.

  Equator: Pressure gradient is balanced by viscosity. Off-equator: “geostrophy”. z=0 at mid depth. (i) Strong equatorial currents. (ii) Enhanced equatorial concentrated meridional overturning circulation (MOC) cell. (iii) Anti-symmetric and broad zonal vel. (u). (iv) Symmetric & confined meridional vel. (v). (v) u, v change sign with depth. w and MOC maximal at mid-depth. (vi) No MOC above above the maximum heating.

  Equator: Pressure gradient is balanced by viscosity. Off-equator: “geostrophy”. z=0 at mid depth. (i) Strong equatorial currents. (ii) Enhanced equatorial concentrated meridional overturning circulation (MOC) cell. (iii) Anti-symmetric and broad zonal vel. (u). (iv) Symmetric & confined meridional vel. (v). (v) u, v change sign with depth. w and MOC maximal at mid-depth. (vi) No MOC above above the maximum heating. Most features are explained!

Equatorial sector— high resolution (1/8 o simulation) simulation Why? (i)Parametrization of eddy viscosity coefficient. (ii)Turbulence under complete ice cover? Setup: (i)Equatorial section: 10 o S to 10 o N & 0 o E to 45 o E with 1/8 o resolution (360x168 grid); fixed (uniform) ice depth; 20 vertical level (100 m each); (ii)Two configurations: with and without island. (iii)Maximum geothermal heating at 6 o N. (iv)Much lower viscosity coefficient!  Turbulence.

Melting rate Almost one order of magnitude larger than atmospheric value. The enhance melting is associated with upwelling of warm water. The enhance melting is associated with upwelling of warm water. Can enhanced melting create hole in the ice? Can enhanced melting create hole in the ice? Can this resolve the question of photosynthetic life under hard Snowball conditions? Can this resolve the question of photosynthetic life under hard Snowball conditions?

Summary (i)The ocean Snowball condition if far from being stagnant. Rich and enhanced dynamics. (ii)Mainly equatorial dynamics. Strong zonal jet; strong & confined meridional overturning circulation (MOC) cell as a result of rotation, geothermal heating, and horizontal viscosity. (iii)Turbulence. Main oceanic characteristics are robust!