boundary layer component (racci -sg3). estratégia de coleta de dados 4 sítios experimentais de rs...

Boundary layer component (RACCI -SG3)

Estratégia de coleta de dados

• 4 sítios experimentais de RS (Abracos, Rebio Jaru, Porto Velho e Guajará-Mirim)

• Sondagens as 00, 06, 12 e 18 GMT e especiais (09,15,18 e 21 GMT)

• Fase I: de 15 a 30/9 de 2002• Fase de transição: de 1 a 15/10/2002• Fase II: de 15 a 30/10/2002

Estatísticas de RS

• Abracos: 214 sondagens

• Rebio Jaru: 125

• Porto Velho: 110

• Guajará-Mirim:143

Sondagens HSB (GM): 36 sondagens

Balão cativo

• içamento noturnos (das 17 as 09 horas) a partir do dia 17/10, içamentos em horários variados (dependendo das condições meteorológicas)

Setembro 2002

Outubro 2002

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ABRACOS

Fluxos de Calor sensível – períodos I e II

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Série temporal das alturas h e hq

• A camada limite convectiva caracteriza-se por possuir suas propriedades bem misturadas (em termos de e de q), sendo a altura determinada pelos critérios:

• / z < 2 K/km

• q / z < 2 g/kg/km

Dia h (m) hq (m) (K) q (g/kg) FASE SÊCA 20/9 2250 2250 308,5 11,0 21/9 1350 1500 306,8 12,0 22/9 1200 1250 305,3 14,0 23/9 1650 1300 307,5 13,8 24/9 1250 1250 305,3 12,8 25/9 1900 1900 307,0 11,2 26/9 1500 1500 307,2 12,0 27/9 1500 1500 306,8 13,0 29/9 1600 1600 306,8 13,4 MÉDIA 1561 1561 306,8 12,6 FASE CHUVOSA 23/10 1400 1400 307,2 13,0 24/10 1200 1200 305,3 12,8 25/10 1000 1100 304,5 13,9 26/10 1250 1200 307,7 13,0 27/20 1800 1700 308,5 13,5 28/10 1700 1700 308,8 11,8 29/10 1500 1300 306,5 12,5 MÉDIA 1410 1370 306,9 12,9

• Precipitação -Ariquemes

Chuva Convectiva – ABRACOS

Perfis de temperatura e umidade

296 298 300 302 304 306 308 310 312 314 316 318 320 322tem peratura potencia l (K )

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Preto- 14 UTC, azul – 17 UTC e vermelho-21 UTC (19/10/2002)

Influência da chuva (27/9/2002) – pastagem

298.00300.00302.00304.00306.00308.00310.00312.00314.00316.00318.00320.00322.00

200.00400.00600.00800.00

1000.001200.001400.001600.001800.002000.002200.002400.002600.002800.003000.003200.003400.003600.003800.004000.004200.004400.004600.004800.005000.005200.00

Influência da chuva 28/09/2002

290.00 300.00 310.00 320.00 330.00

200.00400.00600.00800.00

1000.001200.001400.001600.001800.002000.002200.002400.002600.002800.003000.003200.003400.003600.003800.004000.004200.004400.004600.004800.005000.00

Elementos climáticos

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Cooling and moistening due to a strong rainfall event (28/09/2002)

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NBL (23/09/20002)

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Perfis de temperatura e umidade (23 e 24/09)

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Sodar - ABRACOS

Imagem satélite (24/09/2002)

Seria convecção local??

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PV (vermelho) e GM (azul) sondagem das 06/09/2002 as 600 UTC

RS em PV e GM

Height CBL = 2000 m (18/09/2002)

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Height CBL = 2300 m 20/09/2002

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Série temporal da altura CLC -seco (19-22/09/02)

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200.00400.00600.00800.00

1000.001200.001400.001600.001800.002000.002200.002400.002600.002800.003000.003200.003400.003600.003800.004000.004200.004400.004600.004800.005000.005200.00

Série temporal de aerossóis – abracos

Black Carbon e aerosols PM2.5 SMOCC Fazenda Nossa Senhora

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Formação de Recursos Humanos (1/4)

• Mestrado (Luiz André dos Santos – INPE) que está analisando as diferentes características termodinâmicas observadas na pastagem (período muito seco, chuvas durante a tarde e início de noite, formação de camadas rasas de CLC após ocorrência de chuvas, etc) (bolsista CAPES)


• Iniciação Científica (Eric L. Barroso – ITA). Eric está determinando as alturas da CLC em todos os experimentos já realizados (ABRACOS/RBLE, LBA/TRMM, LBA/RACCI) e classificando as alturas em diferentes condições (seco, chuvoso, pertubado, não-pertubado). Bolsista CNPq-IMilenio). Cooperação Íria Vendrame-ITA


• Iniciação Científica (Paulo Cezar Hanoka – ITA). Hanaoka está determinando a distribuição de chuvas em Rondonia (rede de pluviometros) durante LBA/TRMM e do LBA/RACCI. Bolsista CNPq-Imilenio. Cooperação Profa. Iria Vendrame-ITA


• Doutorado (Rosa do Nascimento Santos - INPE). Rosa está analisando a estrutura da Camada Limite Noturna em Rondônia (LBA/TRMM) através de análises observacionais e de modelagem. Doutorado Sandwich (Universidade Free Amesterda – Prof. Dolman). Bolsista CAPES

"Nocturnal boundary layer (NBL) measurements in Rondonia"

• Experimental AreaExperimental Area

SITES

Rolim de Moura (RM) – pasture siteRebio Jaru (Forest)

Faz. N. Sra (FNS) – pasture site

PERIOD

FEB/1999Wet Season

Mean values of NBL depth – hi, potential temperature on the nocturnal inversion basis –(i), layer specific humidity – q, NBL strength –

i.) LBA – Fazenda N. S.a (pasture)

Local time hi (i) q (g.kg-1) S

19 210 302.3 17.62 3.0

21 207 300.4 17.68 2.6

22 264 301.7 17.47 3.5

01 227 301.0 17.70 3.0

04 235 300.8 17.77 3.5

07 156 299.9 17.94 0.6

ii.) LBA – Rebio Jaru (forest)


17 90 301.1 15.40 1.1

18 152 301.5 15.39 2.8

19 161 300.1 15.48 2.5

20 248 300.6 15.02 3.8

21 251 299.8 15.06 3.6

22 282 300.1 15.03 4.4

05 238 298.4 14.00 3.4

06 278 298.8 13.94 4.0

07 170 296.8 14.03 1.7

iii.) LBA - Rolim de Moura


17 160 303.3 10.97 3.0

18 215 302.4 11.72 2.5

19 197 301.9 12.01 2.5

20 210 301.4 11.80 3.1

21 237 301.5 11.42 3.4

22 207 301.0 11.55 3.8

05 253 299.9 11.24 4.0

06 296 300.6 11.26 4.8

07 215 298.7 11.59 2.4

Δθ

• Transition times and NBL break downTransition times and NBL break down

• Large differences between the total heat flux released by surface (forest, RM and FNS) and biomass (forest), and the heating integrated from the potential temperature in the 3 sites - No balance

Sensilble H (Forest, FNS and RM), biomass heatflux, B (Forest), total heat integrated for the NBL break up period and; boundary layer heating, .

Forest

Date Local Time H (W.m-2) B (W.m-2) Total heat flux (m.K) (m.K)

12/02 06:55 - 07:56 54.72 -25.38 88.3 99.0

15/02 07:00 - 08:06 -6.2 24.05 58.0 7.0

Rolim de Moura

Date Local Time H (W.m-2) Total heat flux (m.K) (m.K)

09/02 06:46 - 07:56 18.7 64.7 32.0

10/02 05:48 - 08:00 12.5 81.7 40.0

14/02 06:49 - 08:17 3.3 10.6 44.0

Fazenda N. S.a

Date Local Time H (W.m-2) Total heat flux (m.K) (m.K)

14/02 07 - 10 52.7 467.8 20.0

24/02 07 - 08 35.0 103.6 4.0

25/02 05 - 08 16.0 141.9 36.0

• In general, was lower than Total heat flux (m.K) measured by eddy correlation system. Smallest differences in the Forest and highest ones in FNS

• Low-level atmospheric jets (Boundary Layer Jets), Low-level atmospheric jets (Boundary Layer Jets), or Nocturnal Jets - NJor Nocturnal Jets - NJ

• DEFINITION: A jet stream occurring in a height below of 1-2 km from the surface, also known as Nocturnal Jet (NJ) because is a common phenomenon under the nighttime stable conditions taking part of the NBL structure and dynamic

• FEATURES:

-Wind speed profile showed a local maximum with minimum velocity value of 7 m.s-1 and that was at least 1.5 m.s-1 higher then the speeds both above and below it. - Jet Core occurrence below of the firsts 1000 m

• STATISTICS:

- 326 radiosonde wind profiles

- 50 profiles showed a NJ configuration

- Most of cases isolated events observed during one single sounding

CASES

RM 11Forest 16FNS 23

- Jet core below 600 m - ~ 58% of cases

- 86% presented wind speed below 10 m.s-1

- Jet Core prevailing direction - Southerly

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Nocturnal jet statistic as observed in Rondônia, during the wet season: i) height of the Jet Core (zj); ii) wind speed at the Jet Core (Vj)

Comparação RASS x RS

Produção Científica

• Apresentação de um poster no Int. Conference on Earth System Modelling (Hamburgo Sept 15-19, 2003)

• Apresentação de um poster no XIII Congresso Brasileiro de Agrometeorologia (Santa Maria Ago 3-7,2003)

Observational aspects of the convective boundary layer at pasture site in Amazonia during LBA/RACCI 2002

G. Fisch, L.A.T. Machado, M.A.F. Silva Dias, R. F. Lyra and A.J.Dolman

Centro Técnico [email protected]

PREVAILING WIND

PASTURE

FOREST

The experimental site was a deforested area (pasture) in the Ji-Paraná Rondônia State, southwest of Amazônia. The experiment was held during Sept 15-30 (dry period) and Oct 15-30, 2002 (wet period) and it consists of rawinsoundings launched at 8, 11, 14 and 17 Local Time (LT). The soundings were made with a Vaisala device (RS80-15G) that measures the profiles of air temperature, pressure, relative humidity and winds (using GPS techniques) up to 20 km (Figure 1 – map, sonde RS80 and pasture scenarious).

This study was supported by Brazilian Agencies (CNPq, CAPES and FAPESP)

The Amazon region is an important source of heat and water vapour for the atmosphere and plays a significant role in the general circulation of the atmosphere. In the last decades, this region is receiving attention from the world scientific community as it has a key impact on the energy and CO2 budget of the planet. This region is suffering a high rate of deforestation and tropical forest has been replaced by pasture and agricultural crops. The latest figures from INPE estimated that approximately 13% of the pristine forest had been converted, mainly in Para and Rondonia State. The RACCI 2002 (Radiation, cloud and climate interactions in the Amazon during the DRY-TO-WET transition season) part of the LBA Project (http://www.lba.cptec.br) investigates the role of the aerosols in triggering the moist convection and also influencing the onset of the rainny season. The aim of this paper is to study the growth of the convective boundary layer over a pasture site in Amazonia during the LBA/RACCI experiment 2002.

1. Introduction

2. Data and site

3. Results

Day h hq q (m) (m) (K) (g/kg)

20/9 2250 2250 308.5 11.0 21/9 1350 1500 306.8 12.0 22/9 1200 1250 305.3 14.0 23/9 1650 1300 307.5 13.8 24/9 1250 1250 305.3 12.8 25/9 1900 1900 307.0 11.2 26/9 1500 1500 307.2 12.0 27/9 1500 1500 306.8 13.0 29/9 1600 1600 306.8 13.4 AVG 1561 1561 306.8 12.6 23/10 1400 1400 307.2 13.0 24/10 1200 1200 305.3 12.8 25/10 1000 1100 304.5 13.9 26/10 1250 1200 307.7 13.0 27/20 1800 1700 308.5 13.5 28/10 1700 1700 308.8 11.8 29/10 1500 1300 306.5 12.5 AVG 1410 1370 306.9 12.9

Table I: Height and thermodynamic characteristics (potential temperature - and specific humidity - q) during the dry (20-29 Sept) and wet (23-29,Oct,2003) periods.

296 298 300 302 304 306 308 310 312 314 316 318 320 322tem pera tura potencia l (K )

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Figure 2: Potential Temperature (left) and Specific Humidity (right) for 11 LT (black), 14 LT (blue) and 17 LT (red) on Sept 28,2002. The radar scope is in the right

3.2 The structure of the CBL and its modification by the rain

At the end of the dry season there was some strong showers like Sept 28, 2002 (38 mm in 3 hours). Before the rain (11 LT) the CBL is very active and well mixed and the height was 1200 m. This structure was totally destroyed by the rain which happens before 14 LT sounding, producing the cooling of the atmosphere and a stable layer. After the rain the solar radiation heats the surface but the thermal inversion was not eroded anymore (Figure 2).

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3.3 The Low level Jet event

During the night of Sept 24, 2002 a low level jet event has occured with strong winds (around 11 m/s at 500 m). This LLJ was probably due to the coupling between an ocluded frontal system in the SE Brazil and the organized convection in Amazonia. This LLJ provokes a strong vertical mechanical mixing that produces an unexpected shallow mixed layer (height of 400 m). The role of this ML in transfering trace gases throughout the residual layer is being under investigation (Figure 3).

Figure 3: The potential temperature (left) and windspeed (right) for Sept 23 (blue) and Sept 24 (red). Sodar data at the top

http://www.lba.cptec.br/

TEOM PM10 SMOCC 2002 Pasture Site FNS

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Trabalhos futuros• Avaliação das características da CL em condições “sujas”

e “razoavelmente limpas” nos sítios de floresta e pastagem

• Características termodinâmicas e dinâmicas da CL para iniciar convecção e chuva na pastagem

• Modificações da estruturas da CL em condições de chuva na pastagem

• Evolução das CLs convectiva e estável nos sítios de floresta e pastagem durante o LBA dry-to-wet

• Estudos de casos da estrutura da CL noturna na pastagem• Ocorrência de jatos de baixos níveis e sua implicação na

estrutura da CL noturna

boundary layer component (racci -sg3). estratégia de coleta de dados 4 sítios experimentais de rs...

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