The seasonality of global land and ocean mass and the changing water cycle

GRACE/GRACE-FO to constrain regional to global Evapotranspiration

10.5194/gstm2020-7 ◽

2020 ◽

Author(s):

John Reager ◽

Madeleine Pascolini-Campbell

Keyword(s):

Large Scale ◽

Water Cycle ◽

Water Flux ◽

Mass Conservation ◽

Mass Change ◽

Global Water Cycle ◽

Basin Scale ◽

Global Land ◽

Terrestrial Water ◽

Global Water

A frontier in hydrology lies in understanding the potential impacts of a warming planet on water cycle variability from regional to global scales. &#160;The fluxes that constitute the terrestrial water cycle present various complexity in observability, with Evapotranspiration (ET) being generally the most challenging variable to quantify directly. &#160;Because of the ability to apply mass conservation and to "close" a water flux budget across scales, mass change measurements present the best opportunity to quantify evapotranspiration and changes in evapotranspiration at larger scales, ranging from basins to global. Here we present work on: (1) using GRACE/GFO observations to estimate basin-scale ET in the continental United States as a target for validation and error analysis of up-scaled ET products from other sources, and (2) using GRACE/GFO observations to estimate ET globally over the full joint record (2003-2020) in order to quantify observed changes in the global water cycle. &#160;We find that because of the way that errors in mass change measurements inherently change in scale (i.e. decreasing with larger study domains), GRACE/GFO measurements offer a very clear and robust uncertainty quantification approach for large scale ET monitoring. &#160;We also find that there is a clear and statistically significant signal in global land ET over the record length that indicates changes in the global water cycle consistent with our understanding of climate change. &#160;These methods and results will be presented and discussed.

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The Influence of Natural and Anthropogenic Forcing on Water and Energy Balance and on Photosynthesis

Land ◽

10.3390/land10111151 ◽

2021 ◽

Vol 10 (11) ◽

pp. 1151

Author(s):

Jaeyoung Song ◽

Sungbo Shim ◽

Ji-Sun Kim ◽

Jae-Hee Lee ◽

Young-Hwa Byun ◽

...

Keyword(s):

Land Surface ◽

Water Cycle ◽

Surface Processes ◽

Net Radiation ◽

Land Surface Processes ◽

Surface Moisture ◽

Detection And Attribution ◽

Aerosol Emission ◽

Global Land ◽

Use Efficiency

Land surface processes are rarely studied in Detection and Attribution Model Inter-comparison Project (DAMIP) experiments on climate change. We analyzed a CMIP6 DAMIP historical experiment by using multi-linear regression (MLRM) and analysis of variance methods. We focused on energy and water budgets, including gross primary productivity (GPP). In MLRM, we estimated each forcing’s contribution and identified the role of natural forcing, which is usually ignored. Contributions of the forcing factors varied by region, and high-ranked variables such as net radiation could receive multiple influences. Greenhouse gases (GHG) accelerated energy and water cycles over the global land surface, including evapotranspiration, runoff, GPP, and water-use efficiency. Aerosol (AER) forcing displayed the opposite characteristics, and natural forcing accounted for short-term changes. A long-term analysis of total soil moisture and water budget indicated that as the AER increases, the available water on the global land increases continuously. In the recent past, an increase in net radiation (i.e., a lowered AER) reduced surface moisture and hastened surface water cycle (GHG effect). The results imply that aerosol emission and its counterbalance to GHG are essential to most land surface processes. The exception to this is GPP, which was overdominated by GHG effects.

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Validation of Clear-Sky Global LAnd Surface Satellite (GLASS) Longwave Radiation Product

10.5194/egusphere-egu2020-2036 ◽

2020 ◽

Author(s):

Qi Zeng ◽

Jie Cheng ◽

Feng Yang

Keyword(s):

Land Surface ◽

Water Cycle ◽

Radiant Energy ◽

Remote Sensing Data ◽

Longwave Radiation ◽

Energy System ◽

Surface Radiation ◽

Radiation Budget ◽

Clear Sky ◽

Global Land

Surface longwave (LW) radiation plays an important rolein global climatic change, which is consist of surface longwave upward radiation (LWUP), surface longwave downward radiation (LWDN) and surface longwave net radiation (LWNR). Numerous studies have been carried out to estimate LWUP or LWDN from remote sensing data, and several satellite LW radiation products have been released, such as the International Satellite Cloud Climatology Project&#8208;Flux Data (ISCCP&#8208;FD), the Global Energy and Water cycle Experiment&#8208;Surface Radiation Budget (GEWEX&#8208;SRB) and the Clouds and the Earth&#8217;s Radiant Energy System&#8208;Gridded Radiative Fluxes and Clouds (CERES&#8208;FSW). But these products share the common features of coarse spatial resolutions (100-280 km) and lower validation accuracy.Under such circumstance, we developed the methods of estimating long-term high spatial resolution all sky&#160; instantaneous LW radiation, and produced the corresponding products from MODIS data from 2000 through 2018 (Terra and Aqua), named as Global LAnd Surface Satellite (GLASS) Longwave Radiation product, which can be free freely downloaded from the website (http://glass.umd.edu/Download.html).In this article, ground measurements collected from 141 sites in six independent networks (AmerciFlux, AsiaFlux, BSRN, CEOP, HiWATER-MUSOEXE and TIPEX-III) are used to evaluate the clear-sky GLASS LW radiation products at global scale. The bias and RMSE is -4.33 W/m2 and 18.15 W/m2 for LWUP, -3.77 W/m2 and 26.94 W/m2 for LWDN, and 0.70 W/m2 and 26.70 W/m2 for LWNR, respectively. Compared with validation results of the above mentioned three LW radiation products, the overall accuracy of GLASS LW radiation product is much better. We will continue to improve the retrieval algorithms and update the products accordingly.

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Future Intensification of the Water Cycle with an Enhanced Annual Cycle over Global Land Monsoon Regions

Journal of Climate ◽

10.1175/jcli-d-18-0628.1 ◽

2019 ◽

Vol 32 (17) ◽

pp. 5437-5452 ◽

Cited By ~ 9

Author(s):

Wenxia Zhang ◽

Tianjun Zhou ◽

Lixia Zhang ◽

Liwei Zou

Keyword(s):

Global Warming ◽

Soil Moisture ◽

Annual Cycle ◽

Water Cycle ◽

East Asian Monsoon ◽

Wet Season ◽

Evaporative Demand ◽

Median Response ◽

Total Runoff ◽

Global Land

Abstract An integrated picture of the future changes in the water cycle is provided focusing on the global land monsoon (GLM) region, based on multimodel projections under the representative concentration pathway 8.5 (RCP8.5) from phase 5 of the Coupled Model Intercomparison Project (CMIP5). We investigate the reservoirs (e.g., precipitable water, soil moisture) and water fluxes (e.g., precipitation P, evaporation E, precipitation minus evaporation P − E, and total runoff) of the water cycle. The projected intensification of the water cycle with global warming in the GLM region is reflected in robust increases in annual-mean P (multimodel median response of 0.81% K−1), E (0.57% K−1), P − E (1.58% K−1), and total runoff (2.08% K−1). Both surface (−0.83% K−1) and total soil moisture (−0.26% K−1) decrease as a result of increasing evaporative demand. Regionally, the Northern Hemispheric (NH) African, South Asian, and East Asian monsoon regions would experience an intensified water cycle, as measured by the coherent increases in P, P − E, and runoff, while the NH American monsoon region would experience a weakened water cycle. Changes in the monthly fields are more remarkable and robust than in the annual mean. An enhanced annual cycle (by ~3%–5% K−1) with a phase delay from the current climate in P, P − E, and runoff is projected, featuring an intensified water cycle in the wet season while little changes or slight weakening in the dry season. The increased seasonality and drier soils throughout the year imply increasing flood and drought risks and agricultural yields reduction. Limiting global warming to 1.5°C, the low warming target set by the Paris Agreement, could robustly reduce additional hydrological risks from increased seasonality as compared to higher warming thresholds.

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Detecting and Attributing Evapotranspiration Deviations Using Dynamical Downscaling and Convection-Permitting Modeling over the Tibetan Plateau

Water ◽

10.3390/w13152096 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2096

Author(s):

Jingyu Dan ◽

Yanhong Gao ◽

Meng Zhang

Keyword(s):

Tibetan Plateau ◽

Land Surface ◽

Dynamical Downscaling ◽

Water Cycle ◽

Monsoon Season ◽

Precipitation Pattern ◽

The Tibetan Plateau ◽

Local Climate ◽

Surface Data ◽

Global Land

Terrestrial evapotranspiration (ET) over the Tibetan Plateau (TP) exerts considerable impacts on the local climate and the water cycle. However, the high-altitude, mountainous areas over the TP pose a challenge for field observations. To finely capture its ET characteristics, we employed dynamical downscaling modeling (DDM) with a 28 km resolution and convection-permitting modeling (CPM) with a 4 km resolution in a normal climatology year, 2014. The benchmark data were the surface energy balance–based global land ET dataset (EB). Other compared data included the Global Land-Surface Data Assimilation System (GLDAS) and two reanalysis datasets: ERA-Interim and ERA5. Results showed that EB exhibits a gradient from the southeastern to northwestern TP, which is in line with the precipitation pattern. GLDAS generally reproduces the annual mean magnitude and pattern but poorly represents the seasonal variations. DDM and CPM perform well in the monsoon season but underestimate ET in the non-monsoon season. The two reanalysis datasets greatly overestimate the ET in the monsoon season, but ERA-Interim performs well in the non-monsoon season. All five datasets underestimate the ET over tundra and snow/ice areas, both in the annual and seasonal means. ET deviations are dominated by precipitation deviations in the monsoon season and by surface net radiation deviations in the non-monsoon season.

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Links between global terrestrial water storage and large-scale modes of climatic variability

10.5194/egusphere-egu2020-6613 ◽

2020 ◽

Author(s):

Tiewei Li

Keyword(s):

Land Surface ◽

Large Scale ◽

Water Cycle ◽

Southern Oscillation ◽

Global Climate ◽

Climatic Variability ◽

Water Storage ◽

Terrestrial Water Storage ◽

Global Land ◽

Terrestrial Water

Large-scale modes of climatic variability, or teleconnections, influence global patterns of climate variability and provide a framework for understanding complex responses of the global water cycle to global climate. Here, we examine how Terrestrial Water Storage (TWS) responds to 14 major teleconnections (TCs) during the 2003&#8211;2016 period based on data obtained from the Gravity Recovery and Climate Experiment (GRACE). By examining correlations between the teleconnections and TWS anomalies (TWSA) data, we find these teleconnections significantly influence TWSA over more than 80.8% of the global land surface. The El Ni&#241;o-Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO), and the Atlantic Multidecadal Oscillation (AMO) are significantly correlated with TWSA variations in 55.8%&#65292;56.2% and 60% the global land surface, while other teleconnections affect TWSA at regional scales. We also explore the TCs&#8217; effect on three key hydrological components, including precipitation (P), evapotranspiration (ET) and runoff (R), and their contribution to TWSA variations in 225 river basins. It&#8217;s found the TCs generally exert the comprehensive but not equally impact on all three components (P, ET and R). Our findings demonstrate a significant and varying effect of multiple TCs in terrestrial hydrological balance.

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The impact of global land-cover change on the terrestrial water cycle

Nature Climate Change ◽

10.1038/nclimate1690 ◽

2012 ◽

Vol 3 (4) ◽

pp. 385-390 ◽

Cited By ~ 238

Author(s):

Shannon M. Sterling ◽

Agnès Ducharne ◽

Jan Polcher

Keyword(s):

Land Cover ◽

Land Cover Change ◽

Water Cycle ◽

Global Land Cover ◽

Global Land ◽

Terrestrial Water ◽

The Impact

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OPERATIONAL 333m BIOPHYSICAL PRODUCTS OF THE COPERNICUS GLOBAL LAND SERVICE FOR AGRICULTURE MONITORING

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprsarchives-xl-7-w3-53-2015 ◽

2015 ◽

Vol XL-7/W3 ◽

pp. 53-56 ◽

Cited By ~ 7

Author(s):

R. Lacaze ◽

B. Smets ◽

F. Baret ◽

M. Weiss ◽

D. Ramon ◽

...

Keyword(s):

Distribution System ◽

Land Surface ◽

Surface Albedo ◽

Water Cycle ◽

Vegetation Indices ◽

Sensor Data ◽

Current Status ◽

Vegetation Dynamic ◽

Area Index ◽

Global Land

The Copernicus Global Land service provides continuously a set of bio-geophysical variables describing, over the whole globe, the vegetation dynamic, the energy budget at the continental surface and some components of the water cycle. These generic products serve numerous applications including agriculture and food security monitoring. The portfolio of the Copernicus Global Land service contains Essential Climate Variables like the Leaf Area Index (LAI), the Fraction of PAR absorbed by the vegetation (FAPAR), the surface albedo, the Land Surface Temperature, the soil moisture, the burnt areas, the areas of water bodies, and additional vegetation indices. They are generated every hour, every day or every 10 days on a reliable automatic basis from Earth Observation satellite data. Beside this timely production, the available historical archives have been processed, using the same innovative algorithms, to get consistent time series as long as possible. All products are accessible, free of charge after registration through FTP/HTTP (<a href="http://land.copernicus.eu/global/"target="_blank">http://land.copernicus.eu/global/</a>) and through the GEONETCast satellite distribution system. The evolution of the service towards the operations at 333m resolution is partly supported by the FP7/ImagineS project which focuses on the retrieval of LAI, FAPAR, fraction of vegetation cover and surface albedo from PROBA-V sensor data. The paper presents the innovations of the 333m biophysical products, make an overview of their current status, and introduce the next steps of the evolution of the Copernicus Global Land service.

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