Transport processes of suspended matter derived from time series in a tidal estuary

1989 ◽  
Vol 94 (C10) ◽  
pp. 14373 ◽  
Author(s):  
I. Grabemann ◽  
G. Krause
Keyword(s):  
Time Series ◽  
Suspended Matter ◽  
Transport Processes ◽  
Tidal Estuary

Preliminary results of the first assessment of 20 years of dust activity in the Patagonia desert (South America) with aerosol products from the MODIS sensors

2021 ◽  
Author(s):  
Santiago Gassó ◽  
Pawan Gupta ◽  
Paul Ginoux ◽  
Robert Levy
Keyword(s):  
Time Series ◽  
South America ◽  
Volcanic Eruptions ◽  
Transport Processes ◽  
Dust Storms ◽  
Biological Processes ◽  
Aerosol Transport ◽  
Deep Blue ◽  
Fire Activity ◽  
Analysis Of Time Series

<p>Aerosol transport processes in the Southern Hemisphere (SH) have been the center of renewed attention in the last two decades because of a number of major geophysical events such as volcanic eruptions (Chile and Argentina), biomass burning (Australia and Chile) and dust storms (Australia and Argentina).<br><br>While volcanic and fire activity in the SH have been the focus of several studies, there is a dearth of satellite assessments of dust activity. The lack of such analysis impairs the understanding of biological processes in the Southern Ocean and of the provenance of dust found in snow at the surface of East Antarctica.<br><br>This presentation will show an analysis of time series of Aerosol Optical Depths over the Patagonia desert in South America. Data from two aerosol algorithms (Dark Target and Deep Blue) will be jointly analyzed to establish a timeline of dust activity in the region. Also, dust proxies from both algorithms will be compared with ground-based observations of visibility at different airports in the area. Once an understanding of frequency and time evolution of the dust activity is achieved, first estimations of ocean-going dust fluxes will be derived.</p>

Recovering climate-related mass transport signals by current and next-generation gravity missions

2020 ◽  
Author(s):  
Roland Pail ◽  
Henryk Dobslaw ◽  
Annette Eicker ◽  
Laura Jensen
Keyword(s):  
Climate Change ◽  
Time Series ◽  
Mass Transport ◽  
Gravity Field ◽  
Transport Processes ◽  
Measuring System ◽  
Climate Projections ◽  
Earth System ◽  
Next Generation ◽  
The Earth

<p>Gravity field missions are a unique geodetic measuring system to directly observe mass transport processes in the Earth system. Past and current gravity missions such as CHAMP, GRACE, GOCE and GRACE-Follow On have improved our understanding of large-scale mass changes, such as the global water cycle, melting of continental ice sheets and mountain glaciers, changes in ocean mass that are closely related to the mass-related component of sea level rise, which are subtle indicators of climate change, on global to regional scale. Therefore, mass transport observations are also very valuable for long-term climate applications. Next Generation Gravity Missions (NGGMs) expected to be launched in the midterm future have set high anticipations for an enhanced monitoring of mass transport in the Earth system with significantly improved spatial and temporal resolution and accuracy. This contribution will present results from numerical satellite mission performance simulations designed to evaluate the usefulness of gravity field missions operating over several decades for climate-related applications. The study is based on modelled of mass transport time series obtained from future climate projections until the year 2100 following the representative emission pathway RCP8.5 Numerical closed-loop simulations will assess the recoverability of mass variability signals by means of different NGGM concepts, e.g. GRACE-type in-line single-pair missions, Bender double-pair mission being composed of a polar and an inclined satellite pair, or high-precision high-low tracking missions following the MOBILE concept, assuming realistic noise levels for the key payload. In the evaluation and interpretation of the results, special emphasis shall be given to the identification of (natural or anthropogenic) climate change signals in dependence of the length of the measurement time series, and the quantification of robustness of derived trends and systematic changes.</p>

scholarly journals New water fractions and transit time distributions at Plynlimon, Wales, estimated from stable water isotopes in precipitation and streamflow

2019 ◽  
Author(s):  
Julia L. A. Knapp ◽  
Colin Neal ◽  
Alessandro Schlumpf ◽  
Margaret Neal ◽  
James W. Kirchner
Keyword(s):  
Time Series ◽  
Stable Isotope ◽  
Transit Time ◽  
Transport Processes ◽  
Water Isotopes ◽  
Data Sets ◽  
Hydrograph Separation ◽  
Stable Water Isotopes ◽  
Isotope Data ◽  
Water Fractions

Abstract. Long-term, high-frequency time series of passive tracers in precipitation and streamflow are essential for quantifying catchment transport and storage processes, but few such data sets are publicly available. Here we describe, present, and make available to the public two extensive data sets of stable water isotopes in streamflow and precipitation at the Plynlimon experimental catchments in mid-Wales. Stable isotope data are available at 7-hourly intervals for 17 months, and at weekly intervals for 4.25 years. Precipitation isotope values were highly variable in both data sets, and the high temporal resolution of the 7-hourly streamwater samples revealed rich isotopic dynamics that were not captured by the weekly sampling. We used ensemble hydrograph separation to calculate new water fractions and transit time distributions from both data sets. Transit time distributions estimated by ensemble hydrograph separation were broadly consistent with those estimated by spectral fitting methods, suggesting that they can reliably quantify the contributions of recent precipitation to streamflow. We found that on average, roughly 3 % of streamwater was made up of precipitation that fell within the previous 7 hours, and 13–15 % of streamwater was made up of precipitation that fell within the previous week. The contributions of recent precipitation to streamflow were highest during large events, as illustrated by comparing new water fractions for different discharges and precipitation rates. This dependence of new water fractions on water fluxes was also reflected in their seasonal variations, with lower new water fractions and more damped catchment transit time distributions in spring and summer compared to fall and winter. We also compared new water fractions obtained from stable water isotopes against those obtained from concentrations of chloride, a solute frequently used as a passive tracer of catchment transport processes. After filtering the chloride data for dry deposition effects, we found broadly similar new water fractions using chloride and stable water isotopes, indicating that these different tracers may yield similar inferences about catchment storage and transport, if potentially confounding factors are eliminated. These stable isotope time series comprise some of the longest and most detailed publicly available catchment isotope data sets. They complement extensive solute data sets that are already publicly available for Plynlimon, enabling a wide range of future analyses of catchment behavior.

scholarly journals A Simple Procedure for Evaluating Global Cosmogenic 14C Production in the Atmosphere Using Neutron Monitor Data

Radiocarbon ◽  
2002 ◽  
Vol 44 (1) ◽  
pp. 149-157 ◽  
Author(s):  
D C Lowe ◽  
W Allan
Keyword(s):  
Time Series ◽  
Solar Cycle ◽  
Atomic Oxygen ◽  
Atmospheric Transport ◽  
Simple Procedure ◽  
Oxidation Mechanism ◽  
Temporal Distribution ◽  
Transport Processes ◽  
Solar Cycle 23 ◽  
Monitor Data

Radiocarbon (14C) produced by cosmogenic processes in the atmosphere reacts rapidly with atomic oxygen to form 14CO. The primary sink for this species is oxidation by the OH radical, the single most important oxidation mechanism for pollutants in the atmosphere. Hence, knowledge of the spatial and temporal distribution of 14CO allows important inferences to be made about atmospheric transport processes and the distribution of OH. Because the chemical lifetime of 14CO against OH attack is relatively short, 1–3 months, its distribution in the atmosphere should show modulations due to changes in 14C production caused by variations in the solar cycle. In this work we present a simple methodology to provide a time series of global 14C production to help interpret time series of atmospheric 14CO measurements covering the whole of solar cycle 23. We use data from neutron monitors, a readily available proxy for global 14C production, and show that an existing 6-year time series of 14CO data from Baring Head, New Zealand, tracks changes in global 14C production at the onset of solar cycle 23.

scholarly journals Reconstruction of MODIS total suspended matter time series maps by DINEOF and validation with autonomous platform data

2011 ◽  
Vol 61 (8) ◽  
pp. 1205-1214 ◽  
Author(s):  
Bouchra Nechad ◽  
Aida Alvera-Azcaràte ◽  
Kevin Ruddick ◽  
Naomi Greenwood
Keyword(s):  
Time Series ◽  
Suspended Matter ◽  
Total Suspended Matter

Assimilation of satellite data to 3D hydrodynamic model of Lake Säkylän Pyhäjärvi

2015 ◽  
Vol 71 (7) ◽  
pp. 1033-1039 ◽  
Author(s):  
Akiko Mano ◽  
Olli Malve ◽  
Sampsa Koponen ◽  
Kari Kallio ◽  
Antti Taskinen ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Time Series ◽  
Satellite Data ◽  
Suspended Matter ◽  
Concentration Field ◽  
Total Suspended Matter ◽  
Observation Data ◽  
Lake Area ◽  
Lake Surface ◽  
Spatial Differences

To analyze the applicability of direct insertion of total suspended matter (TSM) concentration field based on turbidity derived from satellite data to numerical simulation, dispersion studies of suspended matter in Lake Säkylän Pyhäjärvi (lake area 154 km2; mean depth 5.4 m) were conducted using the 3D COHERENS simulation model. To evaluate the practicality of direct insertion, five cases with different initialization frequencies were conducted: (1) every time, when satellite data were available; (2) every 10 days; (3) 20 days; (4) 30 days; and (5) control run without repeated initialization. To determine the effectiveness of initialization frequency, three methods of comparison were used: simple spatial differences of TSM concentration without biomass in the lake surface layer; averaged spatial differences between initialization data and the forecasts; and time series of TSM concentration and observation data at 1 m depth at the deepest point of the lake. Results showed that direct insertion improves the forecast significantly, even if it is applied less often.

Investigations on Suspended Matter Transport Processes in Estuaries and Coastal Waters

1990 ◽  
pp. 165-171
Author(s):  
Walter Puls ◽  
Manfred Lobmeyr ◽  
Agmar Müller ◽  
Matthias Schünemann ◽  
Herbert Kühl
Keyword(s):  
Suspended Matter ◽  
Coastal Waters ◽  
Transport Processes ◽  
Matter Transport
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