Numerical and observational study of the dynamics of the Paracas Wind, associated with aeolian

transport into the ocean off the coast of Ica - Peru

Julio Quijano,K. Takahashi, B. Dewitte

LMI-DISCOH Lima, Perú 29-30th march 2012

GOES 1207OCT200415:00 HL

Is a weather phenomenon between Pisco and San Juan. It’s a storm of dust and sand present during all year with more frecuency and strongly in August between the 14:00 and 18:00 hours local time.

Escobar, 1993

1-4 Hours weak5-8 Hours moderate>8 Hours strong

1. PARACAS WIND (VP)

73.7%

JUN-SET

70.%

14-16hrs

Data: 1948-1990

Duration

GOES 1207OCT200415:00 HL

Visibilidad (Km)

Tiempo (Hora Local)

2. CONSEQUENCES of VP: Decrease of visibility

Velocidad(Km)

07sep2011 – ParaSEx-II

GOES 1207OCT200415:00 HL

2. CONSEQUENCES of VP: Increase marine productivity by Iron imput

Shao et al., 2011

???

Boyd et al., 2009

Bloom

Increase biomas and competence of phy.

(South of Australia)

Saukel et al., 2010

2. How is the evolution of VP?:

Escobar,1993

1948-1990

Mahel et al. 2010

Lithics Flux TOC Flux

Gutierrez et al. 2009VP

Dust storm in the world

Enfield, 1981

PP

VIENTO

P1. LITICO

??

?

?

Main Questions:

what process determinate the VP formation?

How much it’s the lithic input to sea?

What’s the source of dust and sand and the horizontal distribution of the dust plume ?

PP: productividad primariaP: pisco

3. What must We know first?

Scheme of the problem

physical processes of regional scale

physical processes of local scale

Hypothesis:

The VP events depends by interaction between local and regional factors related to the increase of gradient presure and the surface radiation in the Paracas desert since early in the morning.07oct2004

Specific goal

1. Validate the atmospheric model MM5.

2. A tridimentional description of VP

3. Calculate the influence of factors of local and regional scale.

4. Calculate the velocity fricction and the threadholds.

5. Make a numeric experiment with the coastal albedo.

6. Calculate the particule trayectories in 3D.

7. Estimate the flux horizontal of dust and sand.

Principal Goal

Determinate the mechanims of the ocurrence and evolution of Paracas Wind and of transport eolic

4. Goals

5. MetodologyData:

In situ: ParaSex-II , Pisco and Marcona Station, Pisco Airport, Sernamp Station, etc.Initialy conditions for the MM5: NCAR / Reanalysis , Optimation Reynols SSTImage Satellyte: MODIS, CALIPSO, GOES 13

Domains of the MM5

Dx max. : 200 metersDt max : 0.25 seg.

a) Validation: Diagrams of dispersion between MM5 result and Data, pearson correlation and calculated the root of mean error square. (after the test of the physic aproximations of the model )

b) We use the model results for describing the evolutions of factor atmospheric before and during the event.

c) We use the model result for apply a lagrangia equation of particle velocity for every instant in the time.

d) The logaritmic profile and the Monin Obukov theory for calculated the friction and the squeme of "random walk" to simulated the turbulence.

e) We use the empiric equation to estimate the horizontal flux of sand and dust.

ParaSEx-II (Mixpaleo- WindA)

5. Preliminary results: Data in situ

5. Preliminary results: Data in situ, Pilot Ballon. 07 September 2011

10:30 hrs. 11:45 hrs.

Wind Profile with meteorologic theodolite

Preparing the pilot ballon

Measurement with meteorologic theodolite

MIXPALEO

WINDA

5. Preliminary results: Time series of wind Velocity

Burk Thomson (Squeme of Planetary Boundary Layer, PBL) , Dx (model)= 45Km km

MIXPALEO

WINDA

Burk Thomson (Squeme of Planetary Boundary Layer, PBL) , Dx (model)= 1.8 km

5. Preliminary results: Time series of wind velocity

5. Preliminary results: Diagrams of dispersion between the Data and MM5 result

Burk ThomsonPBLr=0.5

Gayno-SeamanPBLr=0.8

5. Preliminary results: MM5 result, Wind Velocity between 15:00 and 16:00 Local Time

a b

c d

5. Preliminary results: Evolution of wind velocity at 10 meter above the surface, Dx=250m

Field of wind velocity in 7th September 2011

a) 06:00 LTb) 12:00 LTc) 15:00 LTd) 18:00 LT

“The patron of field it’s sensible to strong variations in the space and the time”

15:00 LT GOES

MODIS / TERRA 15:00 , 07SEP2011

5. Preliminary results:5. Preliminary results: Wind profile (Logarithmic equation) in WINDA

𝑘𝑢𝑠𝑡

=0.8194

𝐿𝑜𝑔 ( 𝑍𝑜)=−2.8209

Zo

Del Dias 05 y 06SET (cond. Neutras):

Finalmente:

5. Preliminary results: Friction velocity (Logarithmic equation) in WINDA

5. Expected result: Friction velocity for find source and dust and sand

Ust > 0.6 m/s(red shaded)

www.meted.ucar.edu

5. Expected result: dust trayectories ,above surface / 07 Oct 2004 Event / MM5 – trayec.gs

750 meters

100meters

J. QuijanoJulio.quijano.v@upch.pe

jjqv09@gmail.com

GRACIAS.