The Impact of Drought on Soil Moisture Trends across Brazilian Biomes

Abstract. Over the past decade, Brazil has experienced severe droughts across its territory, with important implications for soil moisture dynamics. Soil moisture variability has a direct impact on agriculture, water security and ecosystem services. Nevertheless, there is currently little information on how soil moisture across different biomes responds to drought. In this study, we used satellite soil moisture data from the European Space Agency, from 2009 to 2015, to analyze differences in soil moisture responses to drought for each biome of Brazil: Amazon, Atlantic Forest, Caatinga, Cerrado, Pampa and Pantanal. We found an overall soil moisture decline of −0.5 % yr−1 (p<0.01) at the national level. At the biome level, Caatinga presented the most severe soil moisture decline (−4.4 % yr−1), whereas the Atlantic Forest and Cerrado biomes showed no significant trend. The Amazon biome showed no trend but had a sharp reduction of soil moisture from 2013 to 2015. In contrast, the Pampa and Pantanal biomes presented a positive trend (1.6 % yr−1 and 4.3 % yr−1, respectively). These trends are consistent with vegetation productivity trends across each biome. This information provides insights into drought risk reduction and soil conservation activities to minimize the impact of drought in the most vulnerable biomes. Furthermore, improving our understanding of soil moisture trends during periods of drought is crucial to enhance the national drought early warning system and develop customized strategies for adaptation to climate change in each biome.

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Soil Moisture Dynamics in Response to Precipitation and Thinning in a Semi-Dry Forest in Northern Mexico

Water ◽

10.3390/w13010105 ◽

2021 ◽

Vol 13 (1) ◽

pp. 105

Author(s):

Argelia E. Rascón-Ramos ◽

Martín Martínez-Salvador ◽

Gabriel Sosa-Pérez ◽

Federico Villarreal-Guerrero ◽

Alfredo Pinedo-Alvarez ◽

...

Keyword(s):

Soil Moisture ◽

Forest Management ◽

Water Availability ◽

Dry Forest ◽

Rainfall Events ◽

Rainfall Characteristics ◽

Northern Mexico ◽

The Difference ◽

The Impact ◽

Moisture Dynamics

Understanding soil moisture behavior in semi-dry forests is essential for evaluating the impact of forest management on water availability. The objective of the study was to analyze soil moisture based in storm observations in three micro-catchments (0.19, 0.20, and 0.27 ha) with similar tree densities, and subject to different thinning intensities in a semi-dry forest in Chihuahua, Mexico. Vegetation, soil characteristics, precipitation, and volumetric water content were measured before thinning (2018), and after 0%, 40%, and 80% thinning for each micro-catchment (2019). Soil moisture was low and relatively similar among the three micro-catchments in 2018 (mean = 8.5%), and only large rainfall events (>30 mm) increased soil moisture significantly (29–52%). After thinning, soil moisture was higher and significantly different among the micro-catchments only during small rainfall events (<10 mm), while a difference was not noted during large events. The difference before–after during small rainfall events was not significant for the control (0% thinning); whereas 40% and 80% thinning increased soil moisture significantly by 40% and 53%, respectively. Knowledge of the response of soil moisture as a result of thinning and rainfall characteristics has important implications, especially for evaluating the impact of forest management on water availability.

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Six years of total ozone column measurements from SCIAMACHY nadir observations

Atmospheric Measurement Techniques ◽

10.5194/amt-2-87-2009 ◽

2009 ◽

Vol 2 (1) ◽

pp. 87-98 ◽

Cited By ~ 39

Author(s):

C. Lerot ◽

M. Van Roozendael ◽

J. van Geffen ◽

J. van Gent ◽

C. Fayt ◽

...

Keyword(s):

Cross Sections ◽

Total Ozone ◽

Large Scale ◽

European Space Agency ◽

Data Sets ◽

Data Set ◽

Ozone Data ◽

Space Agency ◽

German Aerospace ◽

The Impact

Abstract. Total O3 columns have been retrieved from six years of SCIAMACHY nadir UV radiance measurements using SDOAS, an adaptation of the GDOAS algorithm previously developed at BIRA-IASB for the GOME instrument. GDOAS and SDOAS have been implemented by the German Aerospace Center (DLR) in the version 4 of the GOME Data Processor (GDP) and in version 3 of the SCIAMACHY Ground Processor (SGP), respectively. The processors are being run at the DLR processing centre on behalf of the European Space Agency (ESA). We first focus on the description of the SDOAS algorithm with particular attention to the impact of uncertainties on the reference O3 absorption cross-sections. Second, the resulting SCIAMACHY total ozone data set is globally evaluated through large-scale comparisons with results from GOME and OMI as well as with ground-based correlative measurements. The various total ozone data sets are found to agree within 2% on average. However, a negative trend of 0.2–0.4%/year has been identified in the SCIAMACHY O3 columns; this probably originates from instrumental degradation effects that have not yet been fully characterized.

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Evaluation of the Performance of SM2RAIN-Derived Rainfall Products over Brazil

Remote Sensing ◽

10.3390/rs11091113 ◽

2019 ◽

Vol 11 (9) ◽

pp. 1113 ◽

Cited By ~ 9

Author(s):

Franklin Paredes-Trejo ◽

Humberto Barbosa ◽

Carlos A. C. dos Santos

Keyword(s):

Soil Moisture ◽

Pearson Correlation ◽

European Space Agency ◽

Rainfall Events ◽

Error Components ◽

Space Agency ◽

Daily Scale ◽

Bioclimatic Conditions ◽

Heavy Rainfall Events

Microwave-based satellite soil moisture products enable an innovative way of estimating rainfall using soil moisture observations with a bottom-up approach based on the inversion of the soil water balance Equation (SM2RAIN). In this work, the SM2RAIN-CCI (SM2RAIN-ASCAT) rainfall data obtained from the inversion of the microwave-based satellite soil moisture (SM) observations derived from the European Space Agency (ESA) Climate Change Initiative (CCI) (from the Advanced SCATterometer (ASCAT) soil moisture data) were evaluated against in situ rainfall observations under different bioclimatic conditions in Brazil. The research V7 version of the Tropical Rainfall Measurement Mission Multi-satellite Precipitation Analysis (TRMM TMPA) was also used as a state-of-the-art rainfall product with an up-bottom approach. Comparisons were made at daily and 0.25° scales, during the time-span of 2007–2015. The SM2RAIN-CCI, SM2RAIN-ASCAT, and TRMM TMPA products showed relatively good Pearson correlation values (R) with the gauge-based observations, mainly in the Caatinga (CAAT) and Cerrado (CER) biomes (R median > 0.55). SM2RAIN-ASCAT largely underestimated rainfall across the country, particularly over the CAAT and CER biomes (bias median < −16.05%), while SM2RAIN-CCI is characterized by providing rainfall estimates with only a slight bias (bias median: −0.20%), and TRMM TMPA tended to overestimate the amount of rainfall (bias median: 7.82%). All products exhibited the highest values of unbiased root mean square error (ubRMSE) in winter (DJF) when heavy rainfall events tend to occur more frequently, whereas the lowest values are observed in summer (JJA) with light rainfall events. The SM2RAIN-based products showed larger contribution of systematic error components than random error components, while the opposite was observed for TRMM TMPA. In general, both SM2RAIN-based rainfall products can be effectively used for some operational purposes on a daily scale, such as water resources management and agriculture, whether the bias is previously adjusted.

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Weak Land–Atmosphere Coupling Strength in HadAM3: The Role of Soil Moisture Variability

Journal of Hydrometeorology ◽

10.1175/jhm445.1 ◽

2005 ◽

Vol 6 (5) ◽

pp. 670-680 ◽

Cited By ~ 35

Author(s):

David M. Lawrence ◽

Julia M. Slingo

Keyword(s):

Boundary Layer ◽

Soil Moisture ◽

Coupling Strength ◽

General Circulation ◽

General Circulation Models ◽

Soil Conditions ◽

Wide Range ◽

The Impact ◽

Soil Moisture Variability ◽

Moisture Variability

Abstract A recent model intercomparison, the Global Land–Atmosphere Coupling Experiment (GLACE), showed that there is a wide range of land–atmosphere coupling strengths, or the degree that soil moisture affects the generation of precipitation, amongst current atmospheric general circulation models (AGCMs). Coupling strength in the Hadley Centre atmosphere model (HadAM3) is among the weakest of all AGCMs considered in GLACE. Reasons for the weak HadAM3 coupling strength are sought here. In particular, the impact of pervasive saturated soil conditions and low soil moisture variability on coupling strength is assessed. It is found that when the soil model is modified to reduce the occurrence of soil moisture saturation and to encourage soil moisture variability, the soil moisture–precipitation feedback remains weak, even though the relationship between soil moisture and evaporation is strengthened. Composites of the diurnal cycle, constructed relative to soil moisture, indicate that the model can simulate key differences in boundary layer development over wet versus dry soils. In particular, the influence of wet or dry soil on the diurnal cycles of Bowen ratio, boundary layer height, and total heat flux are largely consistent with the observed influence of soil moisture on these properties. However, despite what appears to be successful simulation of these key aspects of the indirect soil moisture–precipitation feedback, the model does not capture observed differences for wet and dry soils in the daily accumulation of boundary layer moist static energy, a crucial feature of the feedback mechanism.

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Spaceborne monitoring of CO2 emissions from large cities and the impact of aerosols

10.5194/egusphere-egu2020-20599 ◽

2020 ◽

Author(s):

Sander Houweling ◽

Jochen Landgraf ◽

Friedemann Reum ◽

Hein van Heck ◽

Wei Tao ◽

...

Keyword(s):

Co2 Emissions ◽

European Space Agency ◽

Monitoring Network ◽

Atmospheric Measurements ◽

Large Cities ◽

Anthropogenic Co2 ◽

Space Agency ◽

Spatial Coverage ◽

Spaceborne Monitoring ◽

The Impact

International agreements to reduce CO2 emissions call for an independent mechanism for evaluating the compliance with emission reduction targets. Atmospheric measurements can provide important information in support of this goal. However, to do this globally requires a drastic expansion of the existing monitoring network, using a combination of surface measurements and satellites. CO2 sensing satellites can deliver the required spatial coverage, filling in the gaps that are difficult to cover on ground. However, to reach the accuracy that is required for monitoring CO2 from space is a challenge, and even more so for anthropogenic CO2.The European space agency is preparing for the launch of a constellation of satellites for monitoring anthropogenic CO2 within the Copernicus program, starting in 2025. Scientific support studies have been carried out to define this mission in terms of payload and observational requirements. We report on the AeroCarb study, which investigated the impact retrieval errors due to aerosols in CO2 plumes downwind of large cities, and the potential benefit of an onboard aerosol sensor to help mitigate such errors. In this study, CO2 and aerosol plumes have been simulated at high-resolution for the cities of Berlin and Beijing. The impact of aerosol scattering on spaceborne CO2 measurements has been assessed using a combined CO2-aerosol retrieval scheme, with and without the use of an onboard multi-angular spectropolarimeter (MAP) for measuring aerosols. The results have been used to quantify the accuracy at which the CO2 emissions of Berlin and Beijing can be quantified using inverse modelling and the impact of aerosols depending on the chosen satellite payload.&#160;In this presentation we summarize the outcome of this study, and discuss the implications for the space borne monitoring of anthropogenic CO2 emissions from large cities.

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A Spatial and Temporal Continuum Remotely Sensed Soil Moisture Dataset of the Tibet Plateau From 2002 to 2015

10.5194/egusphere-egu2020-20846 ◽

2020 ◽

Author(s):

Yaokui Cui ◽

Chao Zeng ◽

Jie Zhou ◽

Xi Chen

Keyword(s):

Soil Moisture ◽

Tibetan Plateau ◽

Land Surface ◽

European Space Agency ◽

Remotely Sensed ◽

General Regression Neural Network ◽

Tibet Plateau ◽

The Tibetan Plateau ◽

Space Agency ◽

Spatio Temporal

Abstract:Surface soil moisture plays an important role in the exchange of water and energy between the land surface and the atmosphere, and critical to climate change study. The Tibetan Plateau (TP), known as &#8220;The third pole of the world&#8221; and &#8220;Asia&#8217;s water towers&#8221;, exerts huge influences on and sensitive to global climates. Long time series of and spatio-temporal continuum soil moisture is helpful to understand the role of TP in this situation. In this study, a dataset of 14-year (2002&#8211;2015) Spatio-temporal continuum remotely sensed soil moisture of the TP at 0.25&#176; resolution is obtained, combining MODIS optical products and ESA (European Space Agency) ECV (Essential Climate Variable) combined soil moisture products based on General Regression Neural Network (GRNN). The validation of the dataset shows that the soil moisture is well reconstructed with R2 larger than 0.65, and RMSE less than 0.08 cm3 cm-3 and Bias less than 0.07 cm3 cm-3 at 0.25&#176; and 1&#176; spatial scale, compared with the in-situ measurements in the central of TP. And then, spatial&#160;and&#160;temporal&#160;characteristics and trend of SM over TP were analyzed based on this dataset.Keywords: Soil moisture; Remote Sensing; Dataset; GRNN; ECV; Tibetan Plateau

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The science return of the ESA Hera mission to the binary asteroid Didymos

10.5194/epsc2020-88 ◽

2020 ◽

Author(s):

Patrick Michel ◽

Michael Kueppers ◽

Keyword(s):

Solar System ◽

European Space Agency ◽

Direct Determination ◽

Hypervelocity Impact ◽

The European Union ◽

Long Term Effects ◽

Impact Speed ◽

Asteroid Impact ◽

Space Agency ◽

The Impact

The Hera mission has been approved for development and launch in the new ESA&#160;Space Safety Programme by the ESA Council at Ministerial Level, Space19+, in November 2019. Hera will both offer a high science return and contribute to the first deflection test of an asteroid, in the framework of the international NASA- and ESA-supported Asteroid Impact and Deflection Assessment (AIDA) collaboration. The impact of the NASA DART (Doube Asteroid Redirection Test) spacecraft on the natural satellite of Didymos in October 2022 will change its orbital period around Didymos. As Didymos is an eclipsing binary, and close to the Earth on this date, the change can be detected by Earth-based observers. ESA&#8217;s Hera spacecraft will rendezvous Didymos four years after the impact. Hera&#8217;s instruments will perform the measurements necessary to understand the effect of the DART impact on Didymos&#8217; secondary, in particular its mass, its internal structure, the direct determination of the momentum transfer and the detailed characterization of the crater left by DART. This new knowledge will also provide unique information on many current issues in asteroid science. From small asteroid internal and surface structures, through rubble-pile evolution, impact cratering physics, to the long-term effects of space weathering in the inner Solar System, Hera will have a major impact on many fields. For instance, collisions play a fundamental role in our Solar System history, from planet formation by collisional accretion to cratering of solid surfaces and asteroid family formation by collisional disruption. The fully documented hypervelocity impact experiment provided by DART and Hera will feed collisional models with information obtained at actual asteroid scale and for an impact speed (~6 km/s) that is close to the average impact speed between asteroids in the main belt. Moreover, Hera will perform the first rendezvous with an asteroid binary, characterize the smallest object ever visited (165 m in diameter) and provide the first direct measurement of an asteroid interior. Additionally, studies using Hera data will in turn affect our understanding of the asteroid population as a whole. The scientific legacy of the Hera mission will extend far beyond the core aims of planetary defense. Acknowledgment: The authors acknowledge funding support from ESA and from the European Union&#8217;s Horizon 2020 research and innovation programme under grant agreement No 870377 (project NEO-MAPP), from the European Space Agency and from the French space agency CNES.

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Evaluation of the European Space Agency Climate Change Initiative Soil Moisture Product over China Using Variance Reduction Factor

JAWRA Journal of the American Water Resources Association ◽

10.1111/1752-1688.12478 ◽

2016 ◽

Vol 52 (6) ◽

pp. 1524-1535 ◽

Cited By ~ 3

Author(s):

Xiaoji Shen ◽

Ru An ◽

Jonathan Arthur Quaye-Ballard ◽

Ling Zhang ◽

Zhe Wang

Keyword(s):

Climate Change ◽

Soil Moisture ◽

Variance Reduction ◽

European Space Agency ◽

Reduction Factor ◽

Change Initiative ◽

Space Agency

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Combined measurement and modeling of the hydrological impact of hydraulic redistribution using CLM4.5 at eight AmeriFlux sites

10.5194/hess-2016-24 ◽

2016 ◽

Author(s):

C. Fu ◽

G. Wang ◽

M. L. Goulden ◽

R. L. Scott ◽

K. Bible ◽

...

Keyword(s):

Soil Moisture ◽

Land Surface ◽

Hydraulic Redistribution ◽

Energy Budgets ◽

Soil Moisture Dynamics ◽

Community Land Model ◽

The Us ◽

Hydrological Impact ◽

The Impact ◽

Moisture Dynamics

Abstract. Effects of hydraulic redistribution (HR) on hydrological, biogeochemical, and ecological processes have been demonstrated in the field, but the current generation of standard earth system models does not include a representation of HR. Though recent studies have examined the effect of incorporating HR into land surface models, few (if any) has tackled the magnitude of the HR flux itself or the soil moisture dynamics from which HR magnitude can be directly inferred. Here we incorporated Ryel et al.'s (2002) empirical equation describing HR into the NCAR Community Land Model Version 4.5 (CLM4.5), and examined the ability of the resulting hybrid model to capture the magnitude of HR flux and/or soil moisture dynamics from which HR can be directly inferred, to assess the impact of HR on surface water and energy budgets, and to explore how it may depend on climate regimes and vegetation conditions. Eight AmeriFlux sites characterized by contrasting climate regimes and multiple vegetation types were studied, including the US-Wrc Wind River Crane site in Washington State, the US-SRM Santa Rita Mesquite Savanna site in southern Arizona, and six sites along the Southern California Climate Gradient (US-SCs, g, f, w, c, and d). HR flux, evapotranspiration, and soil moisture were properly simulated in the present study, even in the face of various uncertainties. Our cross-ecosystem comparison showed that the timing, magnitude, and direction (upward or downward) of HR vary across ecosystems, and incorporation of HR into CLM4.5 improved the model-measurement match particularly during dry seasons. Our results also reveal that HR has important hydrological impact (on evapotranspiration, Bowen ratio, and soil moisture) in ecosystems that have a pronounced dry season but are not overall so dry that sparse vegetation and very low soil moisture limit HR.

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