Jacqueline Boutin - Profile on Academia.edu (original) (raw)

Papers by Jacqueline Boutin

Biogeosciences, 2014

The considerable uncertainties in the carbon budget of the Southern Ocean are largely attributed ... more The considerable uncertainties in the carbon budget of the Southern Ocean are largely attributed to unresolved variability, in particular at a seasonal timescale and small spatial scale (∼ 100 km). In this study, the variability of surface pCO 2 and dissolved inorganic carbon (DIC) at seasonal and small spatial scales is examined using a data set of surface drifters including ∼ 80 000 measurements at high spatiotemporal resolution. On spatial scales of 100 km, we find gradients ranging from 5 to 50 µatm for pCO 2 and 2 to 30 µmol kg −1 for DIC, with highest values in energetic and frontal regions. This result is supported by a second estimate obtained with sea surface temperature (SST) satellite images and local DIC-SST relationships derived from drifter observations. We find that dynamical processes drive the variability of DIC at small spatial scale in most regions of the Southern Ocean and the cascade of large-scale gradients down to small spatial scales, leading to gradients up to 15 µmol kg −1 over 100 km. Although the role of biological activity is more localized, it enhances the variability up to 30 µmol kg −1 over 100 km. The seasonal cycle of surface DIC is reconstructed following , using an annual climatology of DIC and a monthly climatology of mixed layer depth. This method is evaluated using drifter observations and proves to be a reasonable first-order estimate of the seasonality in the Southern Ocean that could be used to validate model simulations. We find that small spatial-scale structures are a non-negligible source of variability for DIC, with amplitudes of about a third of the variations associated with the seasonality and up to 10 times the magnitude of largescale gradients. The amplitude of small-scale variability reported here should be kept in mind when inferring temporal changes (seasonality, interannual variability, decadal trends) of the carbon budget from low-resolution observations and models. 0.3 PgC yr −1 in .

Journal of Geophysical Research, 2009

The absolute calibration of the relationship between air-sea CO2 transfer velocity, k, and wind s... more The absolute calibration of the relationship between air-sea CO2 transfer velocity, k, and wind speed, U, has been a topic of debate for some time, because k global average, , as deduced from Geochemical Ocean Sections Study oceanic 14 C inventory has differed from that deduced from experimental k-U relationships. Recently, new oceanic 14C inventories and inversions have lead to a lower . In addition, new measurements performed at sea in high-wind speed conditions have led to new k-U relationship. Meanwhile, quality and sampling of satellite wind speeds has greatly improved. The QuikSCAT scatterometer has provided high-quality wind speeds for more than 7 years. This allows us to estimate the global distributions of k computed using k-U relationships and temperature dependent Schmidt numbers from 1999 to 2006. Given the difficulty of measuring in situ wind speed very accurately, we performed a sensitivity study of the k uncertainty which results from QuikSCAT U uncertainties. New QuikSCAT-buoy U comparisons in the northern Atlantic Ocean and in the Southern Ocean confirm the excellent precision of QuikSCAT U (RMS difference of about 1 m s −1 ), but it is possible that QuikSCAT overestimates wind speeds by 5%, leading to a possible overestimation of k derived with quadratic relationships by 10%. The values obtained with two recent experimental k-U relationships are very close, between 15.9 and 17.9 cm h −1 , and within the error bar of k average deduced from the new oceanic 14 C inventory.

Journal of Marine Systems, 2014

Keywords: Southern Ocean Surface pCO 2 seasonality Autonomous drifters Productivity Satellite chl... more Keywords: Southern Ocean Surface pCO 2 seasonality Autonomous drifters Productivity Satellite chlorophyll Air-Sea CO 2 exchange Upper ocean and mixed layer processes On a mean annual basis, the Southern Ocean is a sink for atmospheric CO 2 . However the seasonality of the air-sea CO 2 flux in this region is poorly documented. We investigate processes regulating air-sea CO 2 flux in a large area of the Southern Ocean (38°S-55°S, 60°W-60°E) that represents nearly one third of the subantarctic zone. A seasonal budget of CO 2 partial pressure, pCO 2 and of dissolved inorganic carbon, DIC in the mixed layer is assessed by quantifying the impacts of biology, physics and thermodynamical effect on seawater pCO 2 . A focus is made on the quantification at a monthly scale of the biological consumption as it is the dominant process removing carbon from surface waters. In situ biological carbon production rates are estimated from high frequency estimates of DIC along the trajectories of CARIOCA drifters in the Atlantic and Indian sector of the Southern Ocean during four spring-summer seasons over the 2006-2009 period. Net community production (NCP) integrated over the mixed layer is derived from the daily change of DIC, and mixed layer depth estimated from Argo profiles. Eleven values of NCP are estimated and range from 30 to 130 mmol C m −2 d −1 . They are used as a constraint for validating satellite net primary production (NPP). A satellite data-based global model is used to compute depth integrated net primary production, NPP, for the same periods along the trajectories of the buoys. Realistic NCP/ NPP ratios are obtained under the condition that the SeaWiFS chlorophyll are corrected by a factor of ≈2-3, which is an underestimation previously reported for the Southern Ocean. Monthly satellite based NPP are computed over the 38°S-55°S, 60°W-60°E area. pCO 2 derived from these NPP combined with an export ratio, and taking into account the impact of physics and thermodynamics is in good agreement with the pCO 2 seasonal climatology of Takahashi (2009). On an annual timescale, mean NCP values, 4.4 to 4.9 mol C m −2 yr −1 are ≈4-5 times greater than air-sea CO 2 invasion, 1.0 mol C m −2 yr −1 . Our study based on in situ and satellite observations provides a quantitative estimate of both seasonal and mean annual uptake of CO 2 in the subantarctic zone of the Southern Ocean. These results bring important constraints for ocean circulation and biogeochemical models investigating future changes in the Southern Ocean CO 2 fluxes.

Journal of Geophysical Research, 2001

The fugacity of carbon dioxide (fCO2) in tropical Atlantic surface waters was hourly monitored by... more The fugacity of carbon dioxide (fCO2) in tropical Atlantic surface waters was hourly monitored by a drifting carbon interface ocean atmosphere (CARIOCA) buoy from June to September 1997 during strong seasonal equatorial upwelling. The buoy drifted along the northern side of the equatorial cold tongue from 0.2°S, 7.5°W to 0.2°N, 12.5°W (June 20 to July 3). An inverse trend between

Global Biogeochemical Cycles, 2011

1] CARIOCA drifters and ship data from several cruises in the Subantarctic Zone (SAZ) of the Paci... more 1] CARIOCA drifters and ship data from several cruises in the Subantarctic Zone (SAZ) of the Pacific Ocean, approximately 40°S-55°S, have been used in order to investigate surface CO 2 partial pressure (pCO 2 ) and dissolved inorganic carbon (DIC) patterns. The highest DIC values were determined in regions of deep water formation, characterized by deep mixed layer depths (MLD) as estimated from Argo float profiles. As a result, these areas act as sources of CO 2 to the atmosphere. Using an empirical linear relationship between DIC, sea surface temperature (SST), and MLD, we then combine DIC with A T based on salinity and compute pCO 2 . Finally, we derive monthly fields of air-sea CO 2 flux in the SAZ. Our fit predicts the existence of a realistic seasonal cycle, close to equilibrium with the atmosphere in winter and a sink when biological activity takes place. It also reproduces the impact that deep water formation regions close to the Subantarctic Front (SAF) and in the eastern part of the SAZ have on the uptake capacity of the area. These areas, undersampled in previous studies, have high pCO 2 , and as a result, our estimates (0.05 ± 0.03 PgC yr −1 ) indicate that the Pacific SAZ acts as a weaker sink of CO 2 than suggested by previous studies which neglect these source regions.

Seasonal and interannual CO2 fluxes for the central and eastern equatorial Pacific Ocean as determined from fCO2-SST relationships

Page 1. Seasonal and interannual CO2 fluxes for the central and eastern equatorial Pacific Ocean ... more Page 1. Seasonal and interannual CO2 fluxes for the central and eastern equatorial Pacific Ocean as determined from fCO2-SST relationships Catherine E. Cosca,1 Richard A. Feely,1 Jacqueline Boutin,2 Jacqueline Etcheto ...

Radio Science, 2003

The Soil Moisture and Ocean Salinity (SMOS) mission is aimed at monitoring, globally, surface soi... more The Soil Moisture and Ocean Salinity (SMOS) mission is aimed at monitoring, globally, surface soil moisture and sea surface salinity from radiometric L-band observations. The SMOS radiometer relies upon a two-dimensional (2-D) synthetic aperture concept in order to achieve satisfactory spatial resolution performances for a minimal cost in terms of payload mass and volume. Counterparts of this advantage are reduced

2010 11th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment, 2010

In the present paper, different methods are proposed for the detection and mitigation of the unde... more In the present paper, different methods are proposed for the detection and mitigation of the undesirable effects of radio frequency interference (RFI) in microwave radiometry. The first of these makes use of kurtosis to detect the presence of non-Gaussian signals, whereas the second imposes a threshold on the standard deviation of brightness temperatures, in order to distinguish natural emission variations from RFI. The third approach is based on the use of a threshold applied to the third and fourth Stokes parameters. These methods have been applied and tested with a CAROLS radiometer operating in the L-band. We also used of a spectral analyser in the view of dividing the spectrum into subbands for subband filtering. These instruments were operated during airborne campaigns made in spring 2009 over the South West of France. The performance of different algorithms is analyzed for both of them. We showed that the kurtosis method is well adapted to pulsed RFI, whereas the method based on the second moment is well adapted to continuous-wave RFI. Subband filtering allow us to mitigate RFI effects, the efficience of these method is better using algoritm based on Euclidian distance estimation.

Carols Campaign, Scientific Data Analysis Results

IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium, 2008

The CAROLS L-band radiometer, which is built and designed as a copy of DTU EMIRAD II instrument w... more The CAROLS L-band radiometer, which is built and designed as a copy of DTU EMIRAD II instrument will be used in conjunction with other airborne instruments (in particular the C-band scatterometer STORM) in coordination with in situ field campaigns for future SMOS CAL/VAL activities. A validation campaign with four flights was made over the South West of France and the

An algorithm to retrieve sea surface salinity from SMOS L-band radiometric measurements

International Geoscience and Remote Sensing Symposium (IGARSS), 2007

The European Space Agency SMOS (Soil Moisture and Ocean Salinity) mission aims at obtaining globa... more The European Space Agency SMOS (Soil Moisture and Ocean Salinity) mission aims at obtaining global maps of soil moisture and sea surface salinity from space for large scale and climatic studies. It uses an L-band (1400-1427 MHz) microwave interferometric radiometer by aperture synthesis (MIRAS) to measure brightness temperature at the Earth surface at horizontal and vertical polarizations (Th and Tv).

Combined Airborne Radio-instruments for ocean and Land Studies (CAROLS)

The CAROLS, L band radiometer, is built and designed as a copy of EMIRAD II radiometer of DTU tea... more The CAROLS, L band radiometer, is built and designed as a copy of EMIRAD II radiometer of DTU team. It is a Correlation radiometer with direct sampling and fully polarimetric (i.e 4 Stockes). It will be used in conjunction with other airborne instruments (in particular the C-Band scatterometer (STORM) and IEEC GPS system, Infrared CIMEL radiometer, one visible camera), in

11th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment, MicroRad 2010 - Proceedings, 2010

The CAROLS, L band radiometer, is built and designed as a copy of EMIRAD II radiometer of DTU tea... more The CAROLS, L band radiometer, is built and designed as a copy of EMIRAD II radiometer of DTU team. It is a Correlation radiometer with direct sampling and fully polarimetric (i.e 4 Stockes). It will be used in conjunction with other airborne instruments (in particular the C-Band scatterometer (STORM) and IEEEC GPS system, Infrared CIMEL radiometer and one visible camera), in coordination with in situ field campaigns for SMOS CAL/VAL. The instruments are implemented on board the French research airplane ATR42. A scientific campaign with thirteen flights is realized over south-western France, Valencia site and Bay of Biscay (Atlantic Ocean) in spring 2009. In order to qualify the radiometer data, different types of aircraft movements were realized: circle flights, wing and nose wags. Simultaneously to flights, different ground measurements were made over continental surfaces and ocean. Results show a good quality of data. For continental surfaces, important Radio-Frequency Interferences (RFI) were observed over a large part of the studied region.

Sea surface emissivity at L-band: results of the WInd and Salinity Experiments WISE 2000 and 2001 and preliminary results from FROG 2003

Two field experiments named WISE (WInd and Salinity Experiment) were sponsored by the European Sp... more Two field experiments named WISE (WInd and Salinity Experiment) were sponsored by the European Space Agency (ESA) to better understand the wind and sea state effects on the L-band brightness temperatures. They took place at the Casablanca oil rig located in the North Mediterranean Sea, 40 km off shore the Ebro river delta: WISE 2000 from November 25 to December

horizonal (H) polarization up to 0.5 K/(m/s), and decreasing at vertical (V) polarization down to... more horizonal (H) polarization up to 0.5 K/(m/s), and decreasing at vertical (V) polarization down to 0.2 K/(m/s) at 65 incidence angle. The sensitivity of to significant wave height extrapolated to nadir is 1 K/m, increasing at H-polarization up to 1.5 K/m, and decreasing at V-polarization down to 0.5 K/m at 65 .A modulation of the instantaneous brightness temperature is found

Radio Science, 2003

Citation: Camps, A., et al., L-band sea surface emissivity: Preliminary results of the WISE-2000 ... more Citation: Camps, A., et al., L-band sea surface emissivity: Preliminary results of the WISE-2000 campaign and its application to salinity retrieval in the SMOS mission,

Proceedings of the IEEE, 2000

Proceedings of the IEEE, 2000

| Soil Moisture and Ocean Salinity, European Space Agency, is the first satellite mission address... more | Soil Moisture and Ocean Salinity, European Space Agency, is the first satellite mission addressing the challenge of measuring sea surface salinity from space. It uses an L-band microwave interferometric radiometer with aperture synthesis (MIRAS) that generates brightness temperature images, from which both geophysical variables are computed. The retrieval of salinity requires very demanding performances of the instrument in terms of calibration and stability. This paper highlights the importance of ocean salinity for the Earth's water cycle and climate; provides a detailed description of the MIRAS instrument, its principles of operation, calibration, and imagereconstruction techniques; and presents the algorithmic approach implemented for the retrieval of salinity from MIRAS observations, as well as the expected accuracy of the obtained results.

Journal of Marine Systems, 2010

Biogeosciences, 2014

The considerable uncertainties in the carbon budget of the Southern Ocean are largely attributed ... more The considerable uncertainties in the carbon budget of the Southern Ocean are largely attributed to unresolved variability, in particular at a seasonal timescale and small spatial scale (∼ 100 km). In this study, the variability of surface pCO 2 and dissolved inorganic carbon (DIC) at seasonal and small spatial scales is examined using a data set of surface drifters including ∼ 80 000 measurements at high spatiotemporal resolution. On spatial scales of 100 km, we find gradients ranging from 5 to 50 µatm for pCO 2 and 2 to 30 µmol kg −1 for DIC, with highest values in energetic and frontal regions. This result is supported by a second estimate obtained with sea surface temperature (SST) satellite images and local DIC-SST relationships derived from drifter observations. We find that dynamical processes drive the variability of DIC at small spatial scale in most regions of the Southern Ocean and the cascade of large-scale gradients down to small spatial scales, leading to gradients up to 15 µmol kg −1 over 100 km. Although the role of biological activity is more localized, it enhances the variability up to 30 µmol kg −1 over 100 km. The seasonal cycle of surface DIC is reconstructed following , using an annual climatology of DIC and a monthly climatology of mixed layer depth. This method is evaluated using drifter observations and proves to be a reasonable first-order estimate of the seasonality in the Southern Ocean that could be used to validate model simulations. We find that small spatial-scale structures are a non-negligible source of variability for DIC, with amplitudes of about a third of the variations associated with the seasonality and up to 10 times the magnitude of largescale gradients. The amplitude of small-scale variability reported here should be kept in mind when inferring temporal changes (seasonality, interannual variability, decadal trends) of the carbon budget from low-resolution observations and models. 0.3 PgC yr −1 in .

Journal of Geophysical Research, 2009

The absolute calibration of the relationship between air-sea CO2 transfer velocity, k, and wind s... more The absolute calibration of the relationship between air-sea CO2 transfer velocity, k, and wind speed, U, has been a topic of debate for some time, because k global average, , as deduced from Geochemical Ocean Sections Study oceanic 14 C inventory has differed from that deduced from experimental k-U relationships. Recently, new oceanic 14C inventories and inversions have lead to a lower . In addition, new measurements performed at sea in high-wind speed conditions have led to new k-U relationship. Meanwhile, quality and sampling of satellite wind speeds has greatly improved. The QuikSCAT scatterometer has provided high-quality wind speeds for more than 7 years. This allows us to estimate the global distributions of k computed using k-U relationships and temperature dependent Schmidt numbers from 1999 to 2006. Given the difficulty of measuring in situ wind speed very accurately, we performed a sensitivity study of the k uncertainty which results from QuikSCAT U uncertainties. New QuikSCAT-buoy U comparisons in the northern Atlantic Ocean and in the Southern Ocean confirm the excellent precision of QuikSCAT U (RMS difference of about 1 m s −1 ), but it is possible that QuikSCAT overestimates wind speeds by 5%, leading to a possible overestimation of k derived with quadratic relationships by 10%. The values obtained with two recent experimental k-U relationships are very close, between 15.9 and 17.9 cm h −1 , and within the error bar of k average deduced from the new oceanic 14 C inventory.

Journal of Marine Systems, 2014

Keywords: Southern Ocean Surface pCO 2 seasonality Autonomous drifters Productivity Satellite chl... more Keywords: Southern Ocean Surface pCO 2 seasonality Autonomous drifters Productivity Satellite chlorophyll Air-Sea CO 2 exchange Upper ocean and mixed layer processes On a mean annual basis, the Southern Ocean is a sink for atmospheric CO 2 . However the seasonality of the air-sea CO 2 flux in this region is poorly documented. We investigate processes regulating air-sea CO 2 flux in a large area of the Southern Ocean (38°S-55°S, 60°W-60°E) that represents nearly one third of the subantarctic zone. A seasonal budget of CO 2 partial pressure, pCO 2 and of dissolved inorganic carbon, DIC in the mixed layer is assessed by quantifying the impacts of biology, physics and thermodynamical effect on seawater pCO 2 . A focus is made on the quantification at a monthly scale of the biological consumption as it is the dominant process removing carbon from surface waters. In situ biological carbon production rates are estimated from high frequency estimates of DIC along the trajectories of CARIOCA drifters in the Atlantic and Indian sector of the Southern Ocean during four spring-summer seasons over the 2006-2009 period. Net community production (NCP) integrated over the mixed layer is derived from the daily change of DIC, and mixed layer depth estimated from Argo profiles. Eleven values of NCP are estimated and range from 30 to 130 mmol C m −2 d −1 . They are used as a constraint for validating satellite net primary production (NPP). A satellite data-based global model is used to compute depth integrated net primary production, NPP, for the same periods along the trajectories of the buoys. Realistic NCP/ NPP ratios are obtained under the condition that the SeaWiFS chlorophyll are corrected by a factor of ≈2-3, which is an underestimation previously reported for the Southern Ocean. Monthly satellite based NPP are computed over the 38°S-55°S, 60°W-60°E area. pCO 2 derived from these NPP combined with an export ratio, and taking into account the impact of physics and thermodynamics is in good agreement with the pCO 2 seasonal climatology of Takahashi (2009). On an annual timescale, mean NCP values, 4.4 to 4.9 mol C m −2 yr −1 are ≈4-5 times greater than air-sea CO 2 invasion, 1.0 mol C m −2 yr −1 . Our study based on in situ and satellite observations provides a quantitative estimate of both seasonal and mean annual uptake of CO 2 in the subantarctic zone of the Southern Ocean. These results bring important constraints for ocean circulation and biogeochemical models investigating future changes in the Southern Ocean CO 2 fluxes.

Journal of Geophysical Research, 2001

The fugacity of carbon dioxide (fCO2) in tropical Atlantic surface waters was hourly monitored by... more The fugacity of carbon dioxide (fCO2) in tropical Atlantic surface waters was hourly monitored by a drifting carbon interface ocean atmosphere (CARIOCA) buoy from June to September 1997 during strong seasonal equatorial upwelling. The buoy drifted along the northern side of the equatorial cold tongue from 0.2°S, 7.5°W to 0.2°N, 12.5°W (June 20 to July 3). An inverse trend between

Global Biogeochemical Cycles, 2011

1] CARIOCA drifters and ship data from several cruises in the Subantarctic Zone (SAZ) of the Paci... more 1] CARIOCA drifters and ship data from several cruises in the Subantarctic Zone (SAZ) of the Pacific Ocean, approximately 40°S-55°S, have been used in order to investigate surface CO 2 partial pressure (pCO 2 ) and dissolved inorganic carbon (DIC) patterns. The highest DIC values were determined in regions of deep water formation, characterized by deep mixed layer depths (MLD) as estimated from Argo float profiles. As a result, these areas act as sources of CO 2 to the atmosphere. Using an empirical linear relationship between DIC, sea surface temperature (SST), and MLD, we then combine DIC with A T based on salinity and compute pCO 2 . Finally, we derive monthly fields of air-sea CO 2 flux in the SAZ. Our fit predicts the existence of a realistic seasonal cycle, close to equilibrium with the atmosphere in winter and a sink when biological activity takes place. It also reproduces the impact that deep water formation regions close to the Subantarctic Front (SAF) and in the eastern part of the SAZ have on the uptake capacity of the area. These areas, undersampled in previous studies, have high pCO 2 , and as a result, our estimates (0.05 ± 0.03 PgC yr −1 ) indicate that the Pacific SAZ acts as a weaker sink of CO 2 than suggested by previous studies which neglect these source regions.

Seasonal and interannual CO2 fluxes for the central and eastern equatorial Pacific Ocean as determined from fCO2-SST relationships

Page 1. Seasonal and interannual CO2 fluxes for the central and eastern equatorial Pacific Ocean ... more Page 1. Seasonal and interannual CO2 fluxes for the central and eastern equatorial Pacific Ocean as determined from fCO2-SST relationships Catherine E. Cosca,1 Richard A. Feely,1 Jacqueline Boutin,2 Jacqueline Etcheto ...

Radio Science, 2003

The Soil Moisture and Ocean Salinity (SMOS) mission is aimed at monitoring, globally, surface soi... more The Soil Moisture and Ocean Salinity (SMOS) mission is aimed at monitoring, globally, surface soil moisture and sea surface salinity from radiometric L-band observations. The SMOS radiometer relies upon a two-dimensional (2-D) synthetic aperture concept in order to achieve satisfactory spatial resolution performances for a minimal cost in terms of payload mass and volume. Counterparts of this advantage are reduced

2010 11th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment, 2010

In the present paper, different methods are proposed for the detection and mitigation of the unde... more In the present paper, different methods are proposed for the detection and mitigation of the undesirable effects of radio frequency interference (RFI) in microwave radiometry. The first of these makes use of kurtosis to detect the presence of non-Gaussian signals, whereas the second imposes a threshold on the standard deviation of brightness temperatures, in order to distinguish natural emission variations from RFI. The third approach is based on the use of a threshold applied to the third and fourth Stokes parameters. These methods have been applied and tested with a CAROLS radiometer operating in the L-band. We also used of a spectral analyser in the view of dividing the spectrum into subbands for subband filtering. These instruments were operated during airborne campaigns made in spring 2009 over the South West of France. The performance of different algorithms is analyzed for both of them. We showed that the kurtosis method is well adapted to pulsed RFI, whereas the method based on the second moment is well adapted to continuous-wave RFI. Subband filtering allow us to mitigate RFI effects, the efficience of these method is better using algoritm based on Euclidian distance estimation.

Carols Campaign, Scientific Data Analysis Results

IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium, 2008

The CAROLS L-band radiometer, which is built and designed as a copy of DTU EMIRAD II instrument w... more The CAROLS L-band radiometer, which is built and designed as a copy of DTU EMIRAD II instrument will be used in conjunction with other airborne instruments (in particular the C-band scatterometer STORM) in coordination with in situ field campaigns for future SMOS CAL/VAL activities. A validation campaign with four flights was made over the South West of France and the

An algorithm to retrieve sea surface salinity from SMOS L-band radiometric measurements

International Geoscience and Remote Sensing Symposium (IGARSS), 2007

The European Space Agency SMOS (Soil Moisture and Ocean Salinity) mission aims at obtaining globa... more The European Space Agency SMOS (Soil Moisture and Ocean Salinity) mission aims at obtaining global maps of soil moisture and sea surface salinity from space for large scale and climatic studies. It uses an L-band (1400-1427 MHz) microwave interferometric radiometer by aperture synthesis (MIRAS) to measure brightness temperature at the Earth surface at horizontal and vertical polarizations (Th and Tv).

Combined Airborne Radio-instruments for ocean and Land Studies (CAROLS)

The CAROLS, L band radiometer, is built and designed as a copy of EMIRAD II radiometer of DTU tea... more The CAROLS, L band radiometer, is built and designed as a copy of EMIRAD II radiometer of DTU team. It is a Correlation radiometer with direct sampling and fully polarimetric (i.e 4 Stockes). It will be used in conjunction with other airborne instruments (in particular the C-Band scatterometer (STORM) and IEEC GPS system, Infrared CIMEL radiometer, one visible camera), in

11th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment, MicroRad 2010 - Proceedings, 2010

The CAROLS, L band radiometer, is built and designed as a copy of EMIRAD II radiometer of DTU tea... more The CAROLS, L band radiometer, is built and designed as a copy of EMIRAD II radiometer of DTU team. It is a Correlation radiometer with direct sampling and fully polarimetric (i.e 4 Stockes). It will be used in conjunction with other airborne instruments (in particular the C-Band scatterometer (STORM) and IEEEC GPS system, Infrared CIMEL radiometer and one visible camera), in coordination with in situ field campaigns for SMOS CAL/VAL. The instruments are implemented on board the French research airplane ATR42. A scientific campaign with thirteen flights is realized over south-western France, Valencia site and Bay of Biscay (Atlantic Ocean) in spring 2009. In order to qualify the radiometer data, different types of aircraft movements were realized: circle flights, wing and nose wags. Simultaneously to flights, different ground measurements were made over continental surfaces and ocean. Results show a good quality of data. For continental surfaces, important Radio-Frequency Interferences (RFI) were observed over a large part of the studied region.

Sea surface emissivity at L-band: results of the WInd and Salinity Experiments WISE 2000 and 2001 and preliminary results from FROG 2003

Two field experiments named WISE (WInd and Salinity Experiment) were sponsored by the European Sp... more Two field experiments named WISE (WInd and Salinity Experiment) were sponsored by the European Space Agency (ESA) to better understand the wind and sea state effects on the L-band brightness temperatures. They took place at the Casablanca oil rig located in the North Mediterranean Sea, 40 km off shore the Ebro river delta: WISE 2000 from November 25 to December

horizonal (H) polarization up to 0.5 K/(m/s), and decreasing at vertical (V) polarization down to... more horizonal (H) polarization up to 0.5 K/(m/s), and decreasing at vertical (V) polarization down to 0.2 K/(m/s) at 65 incidence angle. The sensitivity of to significant wave height extrapolated to nadir is 1 K/m, increasing at H-polarization up to 1.5 K/m, and decreasing at V-polarization down to 0.5 K/m at 65 .A modulation of the instantaneous brightness temperature is found

Radio Science, 2003

Citation: Camps, A., et al., L-band sea surface emissivity: Preliminary results of the WISE-2000 ... more Citation: Camps, A., et al., L-band sea surface emissivity: Preliminary results of the WISE-2000 campaign and its application to salinity retrieval in the SMOS mission,

Proceedings of the IEEE, 2000

Proceedings of the IEEE, 2000

| Soil Moisture and Ocean Salinity, European Space Agency, is the first satellite mission address... more | Soil Moisture and Ocean Salinity, European Space Agency, is the first satellite mission addressing the challenge of measuring sea surface salinity from space. It uses an L-band microwave interferometric radiometer with aperture synthesis (MIRAS) that generates brightness temperature images, from which both geophysical variables are computed. The retrieval of salinity requires very demanding performances of the instrument in terms of calibration and stability. This paper highlights the importance of ocean salinity for the Earth's water cycle and climate; provides a detailed description of the MIRAS instrument, its principles of operation, calibration, and imagereconstruction techniques; and presents the algorithmic approach implemented for the retrieval of salinity from MIRAS observations, as well as the expected accuracy of the obtained results.

Journal of Marine Systems, 2010