THE ATMOSPHERE Tereza Cavazos Department of Physical Oceanography - - PowerPoint PPT Presentation

▶
the atmosphere
SMART_READER_LITE
LIVE PREVIEW

THE ATMOSPHERE Tereza Cavazos Department of Physical Oceanography - - PowerPoint PPT Presentation

May 28, 2023 261 likes •712 views

THE ATMOSPHERE Tereza Cavazos Department of Physical Oceanography Ensenada, Baja California, Mexico The Science of Climate Change: a focus on Central America and the Caribbean Islands Antigua, Guatemala, 14-16 de marzo de 2017 Ve Ver%cal

slide-1
SLIDE 1

Tereza Cavazos Department of Physical Oceanography Ensenada, Baja California, Mexico

THE ATMOSPHERE

The Science of Climate Change: a focus on Central America and the Caribbean Islands Antigua, Guatemala, 14-16 de marzo de 2017

slide-2
SLIDE 2

(Fig. 1.9, Wallace & Hobbs, 2006)

O3

Atmosphere: is the layer of gases

that surrounds the Earth and stays in place due to gravity. Up to 80 km the atmosphere is uniform: AIR

Ve

Ver%cal Structure

O3

slide-3
SLIDE 3

HYDROSPHERE

Earth’s Clima mate System m

Atmosphere

Depends on many processes that occur and interact between the different spheres producing feedbacks

GHGs GHGs

slide-4
SLIDE 4

Earth’s Atmo mosphere

  • Unique composition of gases

(& GHGs) favors life as we know it

  • Unique weather & climate
  • Transports heat,

momentum, and humidity (hydrological cycle)

  • Transports aerosols and
  • ther contaminants (O3,

CFC, NOx, black carbon, etc.)

GHGs: Global Ta = 15oC

CO2 (0.04%) CH4, N2O, water vapor

No GHGs T = -17oC

slide-5
SLIDE 5

External Forcings

  • 9°C

+3°C

Surface Temperature in Antarctica Pre-industrial concentrations of CO2 Human contribution to atmospheric CO2

Temperature ( ° C) Atmospheric CO2 (ppm) Thousands of years before present

CO2 & Temperature in Antarctica since 420,000 yr ago

Last glaciation (Tan = -16°C)

(Petit et al., 1999, Nature, 399, p. 431. Ver Fig. 2.31, W&H, 2006, p. 52)

Last Interglacial

Vostok, Antarctica

2015: 15oC 400

Holocene

slide-6
SLIDE 6

Con Concen centra% a%on

  • n of Gr
  • f Green

eenhou

  • use Gases (GHGs)

se Gases (GHGs)

Concentración de GEIs

1850

Carbone Dioxide (CO2) Methane (CH4) Nitrous Oxide (N2O)

slide-7
SLIDE 7

1970

0-700 m

Global Air Tmean = 15oC OBS: Global Air Temperature Anomaly and Ocean Heat Content

slide-8
SLIDE 8

NATURAL ANTHROPOGENIC

Processes

  • Solar radiation
  • Volcanoes
  • Water vapor
  • GHGs
  • Land-use change
  • Tropospheric Ozone

(AR4 WG1, IPCC 2007 – Sci Basis)

Radiative Forcings in the Atmosphere (Watts/m2) Attribution to climate change

SO2

slide-9
SLIDE 9

NATURAL: Solar radiation, Tectonic plates, Volcanism, El Niño, Decadal Oscillations...

CLIMATE CHANGE

Perturbation of the Earth’s climate due to several forcing mechanisms:

Human Activity: Population growth, Industrial development Land-use change, and Fossil fuel burning

slide-10
SLIDE 10

Weather: Atmospheric phenomena that occur from seconds

to few weeks; this is the deterministic limit for weather forecast. It is the state of the troposphere at any moment. “Weather is what we feel right now”

Climate: Atmospheric phenomena that occur from one

month to much longer time periods. It is the average weather in a place over more than thirty years. “Climate is what we expect”

Weather and Clima mate

slide-11
SLIDE 11

Scales of Variability of Weather and Clima mate

Days

(PDO, AMO) Sunspots

Planetary scale

Droughts , Monsoons

slide-12
SLIDE 12

Sc Scale ales s of f Variability ariability and A and AAribu%o Aribu%on t n to Clima mate Change

2016

slide-13
SLIDE 13

Ferrel Cell: Thermally indirect circulation Jet Stream Hadley Cell: Direct circulation ITCZ

Atmo mospheric Circula%on

slide-14
SLIDE 14

Ferrel Cell Hadley Cell

Meridio Meridional C nal Cir ircula%o ula%on and Hea n and Heat T t Transpo ansport rt

Jet

H

slide-15
SLIDE 15

Annual Temp mperature Range

Large seasonal contrasts Rossby and planetary waves

slide-16
SLIDE 16

dp cpdT dQ D c Q c Q p T p T T t T

H p con p rad

α κ ω − = + + + ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ ∂ ∂ − + ∇ ⋅ − = ∂ ∂ V

(7.37 W&H)

MIDLATITUDES: Horiz ADVECTION of Temp dominates TROPICS: Vert ADV dominates (ω σ compression expansion). Local change and horiz ADV are small from day to day. Easterly waves

.

Warming/diabatic dissipation

Sigma (Static Stability): + Stable, - unstable, 0 neutral

Local change T = Horiz ADV + vertical ADV + radiative + convective diabatic heating

Thermo modynami mic Equa%on

σω + ∇ ⋅ − = ∂ ∂ T t T V

slide-17
SLIDE 17

Tropical Atmo mosphere

30N

slide-18
SLIDE 18

See Fig. 1.18, Wallace and Hobbs, 2006, p. 17

Semi miperma manent Highs and Lows J Jan anuar ary S y SLP LP

slide-19
SLIDE 19

See Fig. 1.19, Wallace and Hobbs, 2006, p. 17

Semi miperma manent Highs and Lows J July S ly SLP LP

slide-20
SLIDE 20

January Precipita%on Clima matology 1998-2015, TRMM

Precipitation (mm hr-1)

Figure from George Kiladis

SPC SPCZ

slide-21
SLIDE 21

July Precipita%on Clima matology 1998-2015, T 1998-2015, TRMM RMM

Precipitation (mm hr-1)

Figure from George Kiladis

slide-22
SLIDE 22

Mean A Mean Annual Pr nnual Prec ecipit ipita%o a%on, n, 1998-2012, T 1998-2012, TRMM RMM

SPC SPCZ IT ITCZ CZ

Figure from George Kiladis

slide-23
SLIDE 23

January and July Precipita%on (mm) derived from CMAP

  • Fig. 1.25, Wallace & Hobbs, 2006, p. 20.

Jan Jul

SPC SPCZ IT ITCZ CZ IT ITCZ CZ

H H H H

slide-24
SLIDE 24

E Eas asterly W erly Waves in es in t the T e Trad ade Win e Winds

Inverted troughs

slide-25
SLIDE 25

E Eas asterly W erly Waves 23 Au es 23 Aug 1995 g 1995

http://apollo.lsc.vsc.edu/classes/met130/notes/chapter15/graphics/ATL_WAVES_VIS.gif

slide-26
SLIDE 26

Zo Zonal Walker Circ rcula%on During Norma mal to La Niña Condi%ons

Div

Pacific Ocean: the tropical climate is coupled (+ feedback)

Conv Low level Easterlies

slide-27
SLIDE 27

High cloud fraction (deep convection) and surface winds SST and surface winds

(Reynolds SST, ISCCP high clouds, Quikscat winds)

In the tropics, convection coincides with warm SST and surface wind convergence. All three define the West Pacific warm pool and the Intertropical Convergence Zone (ITCZ).

East Pacific Cold Tongue

Warm Pool ! ! I T C Z " "

Close rela%on amo mong SST, convec%on and winds

slide-28
SLIDE 28

Januar January y Me Mean an SLP SLP during during La La Niña iña win winters s

Dr Dry in Me y in Mexic ico, the Caribbean and so , the Caribbean and southern US uthern US Z Zon

  • nal cir

al circu cula% la%on

  • n

(e. (e.g., 2008, 1999, 1989 y 1976) g., 2008, 1999, 1989 y 1976)

L H L L H

slide-29
SLIDE 29

Atmo mospheric Rivers and Storms ms Autumn mn-Winter 2016-2017 during a very unusual unusual La La Niña iña (La (La Niña iña Mo Modo doki? ki?) )

slide-30
SLIDE 30

Div

Div

Conv

Canonical La Niña El Niño

slide-31
SLIDE 31

H

an STRF200 (m2 s-1) (STRF = Ψ = gz/f)

L L

(Cavazos and Rivas, 2004)

Te Teleconnec%on during Strong El Niño winters (Strong subtropical je jet and extreme me rainfall, 1976-2000)

slide-32
SLIDE 32

SST, 200 hPa Geopotential Precipitation, 200 hPa Wind

Figure from George Kiladis. Courtesy Tao Zhang, PSD ESRL

El Niño El Niño 2015-2016: A 2015-2016: An unusual e n unusual even ent t

slide-33
SLIDE 33

Sub Subtr tropic pical al Westerly rly Je Jet t during during El El Niño iño

slide-34
SLIDE 34

(Matthews 2000)

The Madden-Julian Oscillation (MJO) and Kelvin Waves

The MJO is also referred to as the 30-60 day or 40-50 day

  • scillation and is the main

intraseasonal/intra-annual fluctuation that explains weather variations near the equatorial regions. It may also affect weather systems in the extratropics, such as the west coast of the U.S. in winter. In its simplest form, the MJO consists of coherent variations

  • OLRan
slide-35
SLIDE 35

Convection Clear Sky

(Matthews 2000)

Life cycle of the MJO during boreal summer (48 days)

OLRan (W m-2) every 3 days

Atmospheric Kelvin Waves and the MJO

http://envam1.env.uea.ac.uk/met_ocean_climate.html

slide-36
SLIDE 36

LN (72) N (142) EN (98) HUR1-3 May-Nov HUR4-5

ENSO ENSO and EP and EPAC T C Tropic pical Cy al Cyclo lones nes

slide-37
SLIDE 37

LN N EN

ENSO ENSO and EP and EPAC T C Tropic pical Cy al Cyclo lones nes Ma May-Nov 1979- v 1979-2010 2010

Warm Pool: SST > 28˚C U200-U850mb (m/s) 10 12 16 9 12 12 9 9

Martinez-Sanchez y Cavazos 2014

slide-38
SLIDE 38

http://www.aoml.noaa.gov/phod/research/tav/awp/

28.5o 28.5o

+AMO

  • AMO

AM AMO a O and NA NAT T T Trop

  • pical Cy

Cycl clon

  • nes

es

slide-39
SLIDE 39

+AMO +PDO

Dec Decadal P adal PaAerns o aAerns of the A f the Atlan%c and P tlan%c and Pacific acific

slide-40
SLIDE 40

Te Teleconnec%on PaAern: The North Atlan%c Oscilla%on

Cold & dry (less snow in the Alps) Temperate and humid (snow & rain) Very cold Cold & dry Temperate and humid Temperate

slide-41
SLIDE 41

NAO Pos

Figure 2A. The North Atlantic Oscillation (NAO). Its "high index" state is shown above, this corresponds to particularly high atmospheric pressure over the Azores, an intense low over Iceland. Ocean winds are stronger and winters milder in the eastern U.S. When the NAO index is low, ocean winds are weaker and the U.S. winter more severe. Changes in ocean temperature distributions are also observed. (Illustration by Fritz Heide & Jack Cook, WHOI)

NAO Neg

Sahara dust & wet & wet Cold Cold

Te Teleconnec%ons of the North Atlan%c Oscilla%on

slide-42
SLIDE 42

CLLJ

EWs

MSD

CFs

NAO / AMO PDO SST ITCZ

Monzón

El Niño/La Niña

(m)

Relevant Phenome mena for the Central Ame merican – – Caribbean Region

slide-43
SLIDE 43

Thank You tcavazos@cicese.mx