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UNIVERSIDAD NACIONAL DE COLOMBIASEDE MEDELLÍN
LIDAR OBSERVATORY OF THE ATMOSPHERE-LOALASERS AND SPECTOSCOPY GROUP
Radiative Forcing Effects on Planetary Boundary Layer Evolution in the Tropical Andean Zone, Medellin – Colombia: Synergy Lidar and Sun
Photometer
Daniel Nisperuza, Andrés Bedoya, Dairo Alegría, Mauricio Múnera, and Álvaro Bastidas
2
OUTLINE
SITE AND INFRASTRUCTURE
OVERVIEW
MEASUREMENTS AND RESULTS
CONCLUSIONS
3
SITE The Lasers and Spectroscopy Group, promotes the development and use of technologies for atmospheric observation of aerosols in Colombia. The support of Latin American Lidar Network - LALINET with technical workshops to effective training of students and young researchers on lidar techniques, and local sponsorship of Air Quality Laboratory - CALAIRE, have enabled the building of the first Lidar Station at Medellín city (Lat: 6.26038°, Long: -75.5778°, Alt: 1471 m.a.s.l.). Overview of the aerosol remote sensing activities is shown here.
LIDAR SYSTEM
S
W E
N3000 m asl.
210 kmPacificocean
Caribean sea
Amazon
476 km
SITE AND INFRASTRUCTURE
1471 m. a.s.l.
4
LALINET: Lidar Observatory of the Atmosphere
Weather Station
PM2.5
Observations of key atmospheric parameters related to aerosol and transport, air quality, and climate.
Lidar
Sun Photometer
5
Lidar SystemLaserGain medium: Nd:YAGEnergy: 0.4 J/1064 nm; 0.2 J/532 nm; 0.08 J/355 nmDivergence: 0.5 mradPulse length: 6 nsPRF: 10 Hz
ReceiverFocal length: 120 cmAperture: 20 cmDetectors: PMT´s
SpecificationsConfiguration: Vertical coaxialAcquisition: 20 - 40 MHz/16 bitSpacial resolution: 3.5; 7.5; 15; and 30 m
Observation of vertical profilesof optical aerosol properties.
6
Sun Photometer NASA-AERONET, Medellín Site
Instrument characteristics and observational specifications
DetectorNumber of filtersNumber of collimatorsField of view/ApertureSolar scanningSky scanningFrequency of Sun acquisitionFrequency of almucantarFrequency of principal plane obs.Frequency of zenith radiance obs.
Silicon5 to 821.2°; one has 10 times the aperture of the other4-quadrant detectorAzimuth and zenith motors0.5 airmass intervals for airmass > 2. Otherwise, 15 minutes apart.At airmass of 4 and 2; 4 times daily4 per dayEvery 10 min, when not in any of the other observing modesCE-318
8
A-Train Satellite constellation
Lase
r
TelescopeSpectral
selection
Register
Atmosphere
CALIOP instrumental characteristics Laser Nd: YAG.
Wavelength 532 nm, 1064 nm
Energy 220 mJ/@ 1064 nm110 mJ/@ 532 nm
Frequency 20.16 Hz
Telescope 1.0 m diameter
Polarization Lineal Paralell and Perpendicular at 532 nm
FOV 130 µrad
Vertical resolution 30-60 m
Horizontal resolution
333 m, 1.5km, 5km
Dinamic range 22 bits
CALIPSOCloud – Aerosol LIDAR Infrared Pathfinder Satellite Observations
CALIPSO
CALIOP
9
Polar trajectory Daytime trajectory
Daytime trajectory over America Daytime trajectoryover Colombia
Daytime trajectoryover Aburra Valley
CALIPSO Trajectories
13:46 Local Time18:46 UTC
300 m
10
The planet boundary layer (PBL) is directly influenced by the Earth’s surface and responds to surface forcing with timescale of an hour or less [Stull,1988].
Height above the earth surface
1 to 2 km
100 to 300 m
Sunrise Sunset Day Time
NBLNBL
Nocturnal Inversion
Residual LayerCBL
Entriment zone Inversion
Classical daytime PBL evolution
OVERVIEW
11
MEASUREMENTS AND RESULTSM
ay
Jun
Jul
Aug
Sep
Oct
Nov
Dic
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30 % Relative Humidity 20 - 50 % Relative Humidity 50 - 100
Days
Month
2013
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dic
02468
1012141618202224262830 % Relative Humidity 20 - 50
% Relative Humidity 50 - 100
Days
Month
2014
Relative Humidity trend since May 2013 to December 2014
12
Year Month Day
2013
Jan. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Feb. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
Mar. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Apr. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
May. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Jun. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Jul. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Aug. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Sep. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Oct. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Nov. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Dic. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Year Month Day
2014
Jan. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Feb. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
Mar. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Apr. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
May. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Jun. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Jul. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Aug. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Sep. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Oct. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Nov. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Dic. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
General measurements schedule (371 days)
13
09:20 10:00 10:40 16:2016:5517:3018:0518:4019:150
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
<1337m>
<3504 m>
Heig
ht [m
]
Local time [hh:mm]
PBL J uly 14 - 2014
<912 m>
Error = 10,7%
PBL obtained by using WCT method
14
0
2
4
6
8
3.9
4.0
4.1
4.2
4.3
4.4
0.000 0.005 0.010 0.015 0.020 0.025
Aerosol [sr-1km-1]
Hei
ght [
km]
January 20 - 2013
Aerosol layers from CALIOP
15
June 16 - 2014
0
2
4
6
8
2.9
3.0
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9
4.0
0.00 0.05 0.10
Aerosol [sr-1km-1]
Hei
ght [
km]
16
1500 1800 2100 2400 2700 3000 3300 3600 3900 4200 45000
1000
2000
3000
4000
5000
6000
CA
LIO
P -
Aero
sol l
aye
r heig
ht [
m]
Lidar-UNAL - PBL height [m]
R=0.72
Line at 45°
Aerosol layer height and PBL height correlation
17
08:45 09:00 09:15 09:30 09:45 10:00 10:15 10:300
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000PBL J une 16 - 2014
Hei
ght [
m]
Local time [hh:mm]
<817 m>
<3030 m>
Error = 20,7%
6 7 8 9 10 11 12 13 14 15 16 17 1815
18
21
24
27
30
Tem
prat
ure
[°C
]
Local time [hh:mm]
dT/dt = 1.96°C/h
6 7 8 9 10 11 12 13 14 15 16 17 180
20
40
60
80
100
% R
elat
ive
Hum
idity dHR/dt = -10%/h
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
0.0000 0.0005 0.0010 0.0015 0.0020
Error=21%
Total [sr-1km-1]
Hei
ght [
km]
Error=21%
0.0000 0.0003 0.0006 0.0009
Aerosol [sr-1km-1]
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
0.0000 0.0005 0.0010 0.0015
Error = 21%
Total [sr-1km-1]
Hei
ght [
km]
Error = 21%
0.0000 0.0001 0.0002 0.0003
Aerosol [sr-1km-1]
07:30 09:00 10:30 12:00 13:30 15:00 16:30 18:00
0.05
0.10
0.15
0.20
0.25
0.30
Error = 11,5%
07:30am - 10:12am
AO
D a
t 532
nm
Local time [hh:mm]
24 DecemberClear sky RH:34%
dAOD/dt = -0.07/h
6 7 8 9 10 11 12 13 14 15 16 17 1815
18
21
24
27
30
Tem
pera
ture
[°C
]
Local time [hh:mm]
dT/dt = 1.73°C/h
6 7 8 9 10 11 12 13 14 15 16 17 180
20
40
60
80
100
% R
ela
tive H
um
idity
dHR/dt = -8%/h
18
08:45 09:00 09:15 09:30 09:45 10:00 10:15 10:300
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
<801 m >
Error= 18,7%
Hei
ght [
m]
Local time [hh:mm]
PBL J une 17 - 2014
<2415 m >
6 7 8 9 10 11 12 13 14 15 16 17 1815
18
21
24
27
30
% R
ela
tive H
um
idity
Local time [hh:mm]
dT/dt = 1.82°C/h
6 7 8 9 10 11 12 13 14 15 16 17 180
20
40
60
80
100
Tem
pera
ture
[°C
]
dHR/dt = -7.6%/h
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
0.000 0.001 0.002 0.003
Error = 39%
Total [sr-1km-1]
Hei
ght
[km
]
Error = 39%
0.0000 0.0005 0.0010 0.0015 0.0020
Aerosol [sr-1km-1]
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
0.0000 0.0005 0.0010 0.0015 0.0020
Error= 39%
Total [sr-1km-1]
Hei
ght [
km]
Error= 39%
0.0000 0.0002 0.0004 0.0006
Aerosol [sr-1km-1]
07:00 08:24 09:48 11:12 12:36 14:00 15:24 16:480.05
0.10
0.15
0.20
0.25
0.30Error = 14,3%
28 DecemberClear sky RH:29%
AO
D a
t 532
nm
Local time [hh:mm]
07:04am - 10:01am
dAOD/dt = -0.05/h
6 7 8 9 10 11 12 13 14 15 16 17 1815
18
21
24
27
30
Tem
pera
ture
[°C
]
Local time [hh:mm]
dT/dt = 2,1°C/h
6 7 8 9 10 11 12 13 14 15 16 17 180
20
40
60
80
100
% R
ela
tive H
um
idity
dHR/dt = -11%/h
19
09:0
0 - 09
-15
09:1
5 - 09
:30
09:3
0 - 09
:45
09:4
5 - 10
:00
10:0
0 - 10
:15
10:1
5 - 10
:30
10:3
0 - 10
:45
10:4
5 - 11
:00
0
1
2
3
4
5
6
7
5.6%5.6%
22.2%
38.9%
16.7%
Day
s
Local time [hh:mm]
11%
Time of PBL lifting
20
CONCLUSIONS
Synergy between Lidar-UNAL, sun photometer and satellite measurements allows the study of vertical structure of the atmosphere in Medellin – Colombia.
On days with similar weather conditions like relative humidity below 50% at 12:00 local time and clear sky, there is a predominance of the effects of solar radiation on Medellin atmosphere giving place to spatial redistribution of aerosol within of PBL around 09:30 – 09:45 local time.
Radiative forcing in Medellin can be seen in behavior of aerosol optical properties: AOD and backscatter coefficient. Backscatter coefficient show a spatial redistribution of aerosol facilitating a decreasing of AOD values while temperature is increasing on surface.
21
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THANKS