Hi h i l hi f hHigh spatial patchiness of methaneHigh spatial patchiness of methane g p pt ti th fl t l d f thconcentrations over the flat landscape of theconcentrations over the flat landscape of the p

Ebro River Delta (NWMediterranean)Ebro River Delta (NWMediterranean)Ebro River Delta (NW Mediterranean)J.‐A. Morguí1,2,*, X. Rodó1, 3, R. Curcoll1, A. Àgueda1, L. Sánchez‐García1, P. Occhipinti1, A. Font1,4, M. Ealo1, C. Grossi1, M. Nofuentes1, R. Arias1, O. Batet1J. A. Morguí , X. Rodó , R. Curcoll , A. Àgueda , L. Sánchez García , P. Occhipinti , A. Font , M. Ealo , C. Grossi , M. Nofuentes , R. Arias , O. Batet1 I tit t C t là d Ciè i d l Cli (IC3) 2 E l D t U i it t d B l 3I tit ió C t l d R i E t di A t 4 E i t l R h G Ki ' C ll L d1 Institut Català de Ciències del Clima (IC3); 2 Ecology Dept., Universitat de Barcelona; 3Institució Catalana de Recerca i Estudis Avançats; 4 Environmental Research Group, King's College London.

(* corresponding author: jamorgui@ic3.cat)( p g j g )

The Ebro River Delta RICE FIELDRICE FIELD DELTA LEFTDELTA LEFTRICE FIELDRICE FIELD DELTA LEFTDELTA LEFTA AThe Ebro River Delta RICE FIELD RICE FIELD leftleft

DELTA LEFT DELTA LEFT SIDESIDE

RICE FIELD RICE FIELD leftleft

DELTA LEFT DELTA LEFT SIDESIDEA1 A4leftleft SIDESIDEleftleft SIDESIDE1 4

The Ebro River Delta landscape is composed of a 320 km2 extensionLLLL

p pagroecosystem, largely paddy fields distributed at both sides of the

LagoonLagoonEstellaEstella

RIVER SIDERIVER SIDE(RIV)(RIV)

LagoonLagoonEstellaEstella

RIVER SIDERIVER SIDE(RIV)(RIV)g y , g y p y

river, and of natural lagoons and marshes along the coast of theEstellaEstella(DEC) (DEC) 

(RIV)(RIV) EstellaEstella(DEC) (DEC) 

(RIV)(RIV)river, and of natural lagoons and marshes along the coast of theMediterranean Sea (A) This area is protected for birdlife and it

( )( )EBRO RIVEREBRO RIVER

( )( )EBRO RIVEREBRO RIVER

Mediterranean Sea (A). This area is protected for birdlife, and itholds the Ebro Delta Natural Park Rice farming and seafoodholds the Ebro Delta Natural Park. Rice farming and seafoodharvesting are the main human activities Aharvesting are the main human activities. A5A2In order to protect the huge aquatic birds communities the rice LagoonLagoonRICE FIELD RICE FIELD 

hLagoonLagoonRICE FIELD RICE FIELD 

h

5A2In order to protect the huge aquatic birds communities, the ricefi ld ll k t fl d d f l ti ft th h ti

ggTancadaTancadarightright

ggTancadaTancadarightright

fields are usually kept flooded for a long time after the harvestingll l l

(TAN)(TAN) DELTA DELTA RIGHT SIDERIGHT SIDE

(TAN)(TAN) DELTA DELTA RIGHT SIDERIGHT SIDEIberianseason, usually until late January. RIGHT SIDERIGHT SIDERIGHT SIDERIGHT SIDEIberian PeninsulaPeninsulaAThis means a long time is left for anaerobic decomposition of A

Aorganic matter (like straw and bird depositions). Through February A3and March rice fields dry and thereafter soil preparation labors can

3y p p

start (end of March). Starting in mid‐April, new water channelized Fig A: Ebro River Delta (NWMediterranean) and field sampling scheme (A); Flooding( ) g p ,from the Ebro River floods the paddy fields allowing rice to grow, to

Fig. A: Ebro River Delta (NW Mediterranean) and field sampling scheme (A); Flooding t t th dd fi ld d l (B D) d fi ld i t t ti (E G)from the Ebro River floods the paddy fields allowing rice to grow, to

flourish and to mature before rice harvesting in September In late stages at the paddy fields and lagoons  (B‐D); and field instrumentation (E‐G).flourish, and to mature, before rice harvesting in September. In lateJanuary water channels are closed in a new cycle to get the fieldsJanuary water channels are closed in a new cycle to get the fieldsdried for aeration and new seeding (B C D)dried for aeration and new seeding. (B, C, D)

Aim of the studyAim of the studyIn 2011 as to prevent the proliferation of an invasive species (Pomacea insularum) spreading over the Northern rice paddies the closure of the left water channels was anticipated to the end of the rice harvesting season (earlyIn 2011, as to prevent the proliferation of an invasive species (Pomacea insularum) spreading over the Northern rice paddies, the closure of the left water channels was anticipated to the end of the rice harvesting season (earlyO t b ) Thi t di ti ( l d t k f 2011 d 2012) t d t i diff t ti i f th d i f il f th l ft fi ld h th i ht k t fl d d til l t J ( Fi A)October). This extraordinary action (only undertaken for 2011 and 2012) turned out in a different timing of the drying up of soils from the left fields whereas the right ones were kept flooded until late January (see Fig. A).

The aim of the study presented here is to take advantage of this large scale casual and unique “experiment” for evaluating the temporal and spatial variability in the distribution of atmospheric Greenhouse Gases originated fromboth the patchiness due to farms owners’ uses and the role of the global water management of the Ebro Delta agroecosystem.p g g g y

M th d l i l D i tiD Methodological DescriptionD Methodological escriptionCC

Continuous measurements of CO2, CH4 and H2O were obtained with a portable instrument designed for aircraft research (Picarro G‐2301‐m,B Cavity Ring‐Down Spectroscopy at 1Hz), powered with batteries and mounted on a car (E). This car circulated at 60 km/h in order to obtain anBspatial resolution around 20 to 30 m, following a track of 70 km (red line in Fig. A). Air was sampled and filtered from an inlet in the front part ofp g ( g ) p pa car (F), at ~ 40 cm above ground (G). No drying system was used: the effect of water vapor was corrected with the build‐in Picarro G‐2301‐m( ), g ( ) y g y psystem. The instrument is periodically calibrated with a set of seven NOAA standards.system. The instrument is periodically calibrated with a set of seven NOAA standards.

Moreover discrete gas samples (flasks) were obtained at five sites (yellow points in Fig A ) for other GHGs analysis in the laboratory (GasF Moreover discrete gas samples (flasks) were obtained at five sites (yellow points in Fig. A1‐5) for other GHGs analysis in the laboratory (GasCh t h )

FChromatography).

The measurement campaigns covered:p g

E • The diurnal cycle: Three tracks were followed, one at sunset, other at dawn, and the third at the new sunset.ETh i t l• The rice crops management cycle:

(Seasonality): After the harvesting in September the closure of the left water channels was effectuated in November 11th 2011 In December(Seasonality): After the harvesting in September, the closure of the left water channels was effectuated in November 11 2011. In December20th and 21st 2011 continuous measurements were conducted for the effects of organic matter decomposition in flooded (both right and left)20th and 21st 2011 continuous measurements were conducted for the effects of organic matter decomposition in flooded (both right and left)

N t li i J 23rd d 24th 2012 j t t th d th i ht t h l l d th t i i ht fi ld till f llareas. Next sampling was in January 23rd and 24th 2012, just at the days the right water channels closed, that is, right fields were still fullyfl d d h h bl i h l f d i h il Th hi d i h h h i h fG flooded, whereas the water table in the left ones was deep in the soils. The third campaign shown here was at the time the water gateways from

h h

Gthe two river sides opened, but with the soils still kept dry (April 18th and 19th 2012), and just after the labors for aeration and seeding havefinished.

(S il di i ) B h id fl d d (20/21 D ) i h id fl d d l f id d i d (23/24 J ) d b h id d i d (18/19 A )(Soil‐water conditions): Both sides flooded (20/21‐Dec), right side flooded vs. left side dried (23/24‐Jan), and both sides dried (18/19‐Apr).

Atmospheric methane concentration variability Wi d i flAtmospheric methane concentration variability. Wind influence.p y Wind influence.21-Dec-2011 07:08:32 - 21-Dec-2011 11:28:21 21-Dec-2011 11:28:47 - 21-Dec-2011 17:29:11 DVariability of methane concentrations

40.8

>=1960

40.8

>=1960

Dec

yin the air blowing over the Ebro Delta >=1960 > 1960 cem

gcan be attributed both to the influence

40.75 [1940 - 1960)�� 40.75 [1940 - 1960)��

mbcan be attributed both to the influence

of the daily cycle (in metabolism ber

of the daily cycle (in metabolismor/and in air stability) and of the

e (º

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e (º

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20or/and in air stability) and of theflooding stage Patchiness can be 40.7

Latit

ude 40.7

Latit

ude

[1900 1920)��

0th

December 21st----------DEC----------------RIV-----------------------TANflooding stage. Patchiness can beattributed also to the size of the L

[1900 - 1920)�� [1900 - 1920)�� -21

December 21st DEC RIV TANattributed also to the size of thediff t i ddi At h i

40.65 [1880 - 1900)�� 40.65 [1880 - 1900)��

1st FLEXPART model simulation in backward mode of the Potential Surfacedifferent rice paddies. Atmospheric t (2 Influence (PSI, 0-300m layer) for the wind arriving at the Ebro Delta inmethane values obtained after the dry< 1880�� < 1880��

201

Influence (PSI, 0 300m layer) for the wind arriving at the Ebro Delta inDecember 21st and January 24th at dawnperiod are similar to the planet

0.6 0.65 0.7 0.75 0.840.6

Longitude (º)

0.6 0.65 0.7 0.75 0.840.6

Longitude (º)

11) December 21st and January 24th at dawn .PSI representation for pixels with a Residence time of the air in thosebackground.

Longitude (º) Longitude ( ) PSI representation for pixels with a Residence time of the air in thosepixels lasting more than 100 seconds are also depicted for three points:

g

40 824-Jan-2012 15:06:48 - 24-Jan-2012 18:49:46

40 823-Jan-2012 15:35:54 - 23-Jan-2012 19:08:20

40 824-Jan-2012 06:33:29 - 24-Jan-2012 10:26:27 J pixels lasting more than 100 seconds are also depicted for three points:

DEC (Lagoon site in the river Ebro left side A1 in Fig A)40.8

>=2500

40.8

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40.8

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an DEC (Lagoon site in the river Ebro left side, A1 in Fig A)RIV (Ri b k it A3 i Fi A)

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nua RIV (River bank site, A3 in Fig A)TAN (L i i h i Eb i h id A i Fi A)40.75

[2400 2500)��

40.75

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ary TAN (Lagoon site in the river Ebro right side, A5 in Fig. A)[2300 - 2400)��[2300 - 2400)�� [2300 - 2400)�� 23

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0.6 0.65 0.7 0.75 0.840.6

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0.6 0.65 0.7 0.75 0.8

40.6

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)

January 24th----------DEC------------------RIV-----------------TANg ( )g ( ) g ( ) January 24th DEC RIV TAN

40.818-Apr-2012 17:09:18 - 18-Apr-2012 21:30:23

40.819-Apr-2012 05:20:46 - 19-Apr-2012 09:36:42

40.819-Apr-2012 11:40:32 - 19-Apr-2012 15:24:28

A

>=1900 >=1900 >=1900

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40 75 [1895 1900)

il 1 The Ebro River valley channelize the winds coming from an Atlantic40.75 [1895 - 1900)�� 40.75 [1895 - 1900)�� 40.75 [1895 - 1900)��

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) [1890 - 1895)�� [1890 - 1895)�� [1890 - 1895)��

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19t The RPSI (Restricted Potential Surface Influence) for January helps

Lat

[1885 - 1890)�� Lati

[1885 - 1890)�� Latit

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The RPSI (Restricted Potential Surface Influence) for January helpsto explain the Mediterranean sea strong influence for the low values(20 to explain the Mediterranean sea strong influence for the low valuesof methane over TAN (La Tancada Lagoon)40.65 [1880 - 1885)�� 40.65 [1880 - 1885)�� 40.65 [1880 - 1885)��

012 of methane over TAN (La Tancada Lagoon).

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0 6 0 65 0 7 0 75 0 840.6

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Sunset /3Sunset /1 Dawn /2 Sunset /3Sunset /1 Dawn /2

E G i U iEuropean Geosciences UnionGeneral Assembly 2012Vienna | Austria | 22 – 27 April 2012| | p