3/5/2017

1

Climate Change

Prof. Binod Kumar BhattaraiDepartment of Engineering Science and Humanities

Pulchowk Campus

Weather Climate

Climate - average weather It includes patterns of temperature, precipitation (rain or snow), humidity, wind and ….

Climate patterns shape natural ecosystems,

Our climate is rapidly changing with disruptive impacts

faster than any seen in the last 2,000 years

progressively worsening impacts.

Guest lecture 2

3/5/2017

2

Climate is the average weather at a given point and time of year, over a long period (typically 30 years).

We expect the weather to change a lot from day to day, but we expect the climate to remain relatively constant.

If the climate doesn’t remain constant, we call it climate change.

The key question is what is a significant change –and this depends upon the underlying level of climate variability

Guest lecture 3

Global meansurfacetemperature

Time/years0 300

4Guest lecture

3/5/2017

3

Global mean temperatures are rising faster with time

100 0.0740.018

50 0.1280.026

Warmest 12 years:1998,2005,2003,2002,2004,2006, 2001,1997,1995,1999,1990,2000

Period Rate

Years /decade

6Guest lecture

3/5/2017

4

Global surface temperature 1855-2010

How is this curve calculated?7Guest lecture

Observed surface temperature trend

Trends significant at the 5% level indicated with a ‘+’. Grey: insufficient data

3/5/2017

5

Other evidence of Climate Change

Glacier retreat

1875 2004

9Guest lecture

Snow cover and Arctic sea ice are decreasing

Spring snow cover shows 5% stepwise drop during 1980s

Arctic sea ice area decreased by 2.7% per decade

10Guest lecture

3/5/2017

6

Rise in global ocean heat content 1955-2005

Some ups and downs, but clear overall increase Levitus et al., 2005, GRL11Guest lecture

Sea-level from satellites: 4 cm rise in last 10 years

12Guest lecture

3/5/2017

7

13Guest lecture

14Guest lecture

3/5/2017

8

Variation of CO2 in different time scales

15Guest lecture

Measurements

Thermometers

A thermometer has two important elements:

a temperature sensor (bulb on a mercury-in-glass thermometer)

some physical change occurs with temperature

some means of converting this physical change into a numerical value

3/5/2017

9

Measurements Solar Spectrum

Measurements Pyranometers

thermoelectric detection

incoming radiation - absorbed by a horizontal blackened surface

resulting increase of temperature is measured through thermocouples connected in series or series-parallel to make a thermopile

active (hot) junctions beneath the blackened receiver surface are heated by the radiation absorbed in the black coating

passive (cold) junctions of the thermopile are in thermal contact with the pyranometer housing, which serves as a heat-sink.

3/5/2017

10

Measurements

Air mass is a representation of the amount of atmosphere radiation that must pass through to reach Earth’s surface.

20Guest lecture

3/5/2017

11

Guest lecture 21

New unit for UV: UV index number from 0 - 20

Solar spectrum [W/m2nm]

CIE’s biological weighting function (≈erythemal action spectrum)

Mathematical well defined

Multiplied (weighted)

Area below the weighted spectrum is multiplied by 40

The number gives the UV index

a number 0 - 20 22Guest lecture

3/5/2017

12

Long term -Skin cancer

Ocular effects

Short term -Erythemal damage in the skin,Cataract in the eye

23Guest lecture

Solar Energy influencing parameters

Altitude

24Guest lecture

3/5/2017

13

Measurements

UV meters

NILU UV meters

Five channels: 305, 312, 320, 340, 380

Plus PAR

Guest lecture 25

Measurements

Aerosol meters

340nm, 380nm, 440nm, 500nm, 675nm, 870nm, 936nm, and 1020nm

3/5/2017

14

1. What is climate change? How is it quantified?

2. How is the solar spectrum look like? What does it indicate?

3. What is a pyranometer? Discuss its working.

4. What is solar UV? What are their positive and negative effects?

5. Is it possible to forecast solar UV? What will be its benefit to the society?

6. What is attenuation of solar energy? How is it attenuated in earth’s atmosphere?

Some review questions….

Climate Change continuation------

Professor Ram Kumar Sharma (PhD)

Department of Engg Sci and Hum

Pulchowk Campus

Guest lecture 28

3/5/2017

15

Aerosols

Guest lecture 29

• Black carbon (BC) is most effective form of PM, its mass fraction in atmospheric aerosol is typically less than 10 percent

• Black carbon emissions originate from a variety of sources

Guest lecture 30

3/5/2017

16

Guest lecture 31

BC emissions can remain in the atmosphere forseveral weeks to a month or moreThe sources of BC emissions vary by regiondepending on lifestyle and the types of fuelused.BC effectsmelting of icewarming of atmosphere,diming at surfaceAtmospheric brown clouds,

Guest lecture 32

3/5/2017

17

Burning of fossil fuels V, Co, Mo, Pb, Ni and Cr

Elements in particulate matters are generated from different sources

Metallurgical processes As, Cr, Cu, Mnand Zn Traffic pollution Fe, Ba, Pb, Cu, Zn, and Cd

Guest lecture 33

Ambient Air sampler

Aerosol Spectrometer

Instruments

Guest lecture 34

3/5/2017

18

AethalometerGuest lecture 35

Guest lecture 36

3/5/2017

19

0 5 10 15 20 250

10

20

30

40

50

60

Universal Coordinated Time

BC

in µ

g/m

3

BCJan

BCFeb

BCMarBCApr

BCMay

Diurnal variation of BC in Biratnagar

Guest lecture 37

Wind rose for Biratnagar

Wind rose diagram a-e (January to May)INDIA

Guest lecture 38

3/5/2017

20

0 20 40 60 80 100 1200

0.5

1

1.5

2

2.5

3

Observed days October2009 to March2010

AO

D50

0 an

d A

ng

stro

m e

xpo

nen

t

AOD

Angstrom exponent

Locations AOD 500 Values

Hanle 0.05-0.09

Nainital 0.059-0.157

Kullu 0.24-0.27

Kathmandu 0.2-1.0

AOD and Ǻngstrӧm exponent α

Guest lecture 39

N D J F M A M J J A S O N D J F M A M J J A S O N D

0

10

20

30

40

50

0

10

20

30

40

50

BC

in u

g/m

3

2008 2009 2010

2008/2009 Winter 0 mm water

2009/2010 Winter 31.0 mm recorded

Monthly variation of BC

Guest lecture 40

3/5/2017

21

0 5 10 15 20 250

10

20

30

40

Coordinated Universal Time (a)

Con

c.of

BC

in µ

g /m

3 Monsoon

Post monsoonWinter

Pre monsoon

0 5 10 15 20 250

0.5

1

1.5

2

2.5

Coordinated Universal Time (b)

Win

d s

pee

d m

/s

Monsoon

Post monsoonWinter

Pre monsoon

30µg/m326µg/m3

13.2µg/m3

6.7µg/m3

Seasonal Variation

Guest lecture 41

0 5 10 15 20 250

5

10

15

20

25

Universal Coordinated Time

BC in

µg

/m3

BCKTM

BC BRT

Diurnal Variation of BC in KTM and BRT

Guest lecture 42

3/5/2017

22

0

1

2

3

4

5

6

7

Ordinary Phoolpati Asthami Nawami Dashin Ekadasi Dwadasi Ordinary

BC

ug/

m3

Before Ghatasthapana

After Purnima

Dashain Festival

Guest lecture 43

0

5

10

15

20

25

30

35

40

45

Working Strike-1 Working Strike-2 BeforeShiv Shiva AfterShiv

BC

ug/

m3

1st June09

6th Dec0913th Feb10

Influence of local events on BC

31st May09 5th Dec09

11thFeb10

Guest lecture 44

3/5/2017

23

Most of the time Angstrom exponent value was ≥1(α 340-

675) shows domination of small particles, originated fromurban pollution and biomass burningMonthly average EC, BC and solar radiation shows afairly anti-correlation.

r=- 0.91 for ECr=- 0.90 for BC

Comparison of AOD500 and carbonaceous aerosols analysis shows the highest values of EC and BC when AOD500 value exceeds 0.5

About 50 % BC of KTM is contributed by vehicles and industries

Guest lecture 45

Air pollution is a major environmental risk to health and is estimated to cause approximately 2 million premature deaths worldwide per year.

Guest lecture 46

3/5/2017

24

Guest lecture 47