Viral and bacterial production in the North Water: in situ measurements, batch-culture experiments and characterization and distribution of a virus–host system

Abstract. Soil moisture can be obtained from in-situ measurements, satellite observations, and model simulations. This study evaluates different methods of combining model, satellite, and in-situ soil moisture data to provide an accurate and spatially-continuous soil moisture product. Three independent soil moisture datasets are used, including an in situ-based product that uses regression kriging (RK) with precipitation, SMAP L4 soil moisture, and model-simulated soil moisture from the Noah model as part of the North American Land Data Assimilation System. Triple collocation (TC), relative error variance (REV), and RK were used to estimate the error variance of each parent dataset, based on which the least squares weighting (LSW) was applied to blend the parent datasets. These results were also compared with that using simple average (AVE). The results indicated no significant differences between blended soil moisture datasets using errors estimated from TC, REV or RK. Moreover, the LSW did not outperform AVE. The SMAP L4 data have a significant negative bias (−18 %) comparing with in-situ measurements, and in-situ measurements are valuable for improving the accuracy of hybrid results. In addition, datasets using anomalies and percentiles have smaller errors than using volumetric water content, mainly due to the reduced bias. Finally, the in situ-based soil moisture and the simple-averaged product from in situ-based and Noah soil moisture are the two optimal datasets for soil moisture mapping. The in situ-based product performs better when the sample density is high, while the simple-averaged product performs better when the station density is low, or measurement sites are less representative.

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In situ measurements of capelin (Mallotus villosus) target strength in the North Pacific Ocean

ICES Journal of Marine Science ◽

10.1093/icesjms/fsn205 ◽

2008 ◽

Vol 66 (2) ◽

pp. 258-263 ◽

Cited By ~ 3

Author(s):

Michael A. Guttormsen ◽

Christopher D. Wilson

Keyword(s):

Pacific Ocean ◽

North Pacific ◽

North Pacific Ocean ◽

In Situ Measurements ◽

Target Strength ◽

Mallotus Villosus ◽

The North ◽

Capelin Mallotus Villosus ◽

The North Pacific

Abstract Guttormsen, M. A. and Wilson, C. D. 2009. In situ measurements of capelin (Mallotus villosus) target strength in the North Pacific Ocean. – ICES Journal of Marine Science, 66: 258–263. In situ measurements of capelin (Mallotus villosus) target strength (TS) were collected during summer 2001–2003 near Kodiak Island in the Gulf of Alaska, using a calibrated EK500 echosounder with 38 and 120 kHz split-beam transducers. Targets were detected over dispersed, night-time aggregations using standard acoustic methods, then filtered using a quality-control algorithm to reject invalid targets. The 38 kHz-based, fitted model estimate was TS = 20 log10L− 70.3 (r2 = 0.30), where L is total length of fish. Compared with other studies, the TS-fitted model at 38 kHz was similar to that calculated from swimbladder morphology measurements from St Lawrence estuary capelin (TS = 20 log10L− 69.3), but resulted in greater estimates than models based on in situ measurements of capelin TS in the Barents Sea (TS = 19.1 log10L−74.0) and northern Atlantic Ocean (TS = 20 log10L − 73.1). The large intraspecific variability exhibited in the fitted TS – L models for this species suggests the use of TS measurements from the geographic region where the data were collected.

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Seasonal and Interannual Variations in China’s Groundwater Based on GRACE Data and Multisource Hydrological Models

Remote Sensing ◽

10.3390/rs12050845 ◽

2020 ◽

Vol 12 (5) ◽

pp. 845

Author(s):

Jianxin Zhang ◽

Kai Liu ◽

Ming Wang

Keyword(s):

Correlation Coefficient ◽

Empirical Orthogonal Function ◽

Seasonal Fluctuation ◽

In Situ Measurements ◽

Orthogonal Function ◽

The North ◽

Function Decomposition ◽

Grace Data ◽

Land Data Assimilation System

In this study, we used in situ measurements for the first time to analyze the applicability and effectiveness of evaluating groundwater storage (GWS) changes across China using Gravity Recovery and Climate Experiment (GRACE) satellite products and hydrological data derived from the WaterGap Global Hydrological Model (WGHM), Global Land Data Assimilation System (GLDAS) and eartH2Observe (E2O). The results show that the GWS derived from GRACE JPL Mascons products combined with GLDAS Noah V2.1 data most accurately reflect the overall distribution of GWS changes in China and the correlation coefficient between the in situ measurements reaches 0.538. The empirical orthogonal function decomposition for GWS indicates clear interannual variation and seasonal variation in China. The trends of China’s GWS changes showed a clear regional characteristic from 2003 to 2016. The GWS in the northeast, central-south, and western junction of Xinjiang-Qinghai-Tibet had increased significantly, and the North China Plain (NCP) had a severe decline. The correlation coefficient between the annual trends of precipitation and GWS was 0.57, and it reached 0.73 when four provinces (Beijing, Tianjin, Shanxi, Hebei) that are wholly or partially located in the NCP were excluded. The seasonal variability of GWS in China was obvious and the volatilities in Jiangxi, Hunan and Fujian provinces were the highest, reaching 6.39 cm, 6.33 cm and 5.20 cm, respectively. The empirical orthogonal function decomposition for GWS and precipitation over China indicated seasonal consistency with a correlation coefficient of 0.76. The awareness of areas with significant depletion and large seasonal fluctuation of GWS help adaptations to manage local GWS situation.

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The retrieval of cloud microphysical properties using satellite measurements and an in situ database

Annales Geophysicae ◽

10.1007/s00585-996-0098-3 ◽

1996 ◽

Vol 14 (1) ◽

pp. 98-106 ◽

Cited By ~ 1

Author(s):

Christophe Poix ◽

Guy Febvre ◽

Anne Fouilloux ◽

Howard Larsen ◽

Jean-Francois Gayet

Keyword(s):

Large Scale ◽

In Situ Measurements ◽

Global Circulation ◽

The North ◽

Microphysical Properties ◽

Microphysical Parameters ◽

Research Aircraft ◽

The North Sea

Abstract. By combining AVHRR data from the NOAA satellites with information from a database of in situ measurements, large-scale maps can be generated of the microphysical parameters most immediately significant for the modelling of global circulation and climate. From the satellite data, the clouds can be classified into cumuliform, stratiform and cirrus classes and then into further sub-classes by cloud top temperature. At the same time a database of in situ measurements made by research aircraft is classified into the same sub-classes and a statistical analysis is used to derive relationships between the sub-classes and the cloud microphysical properties. These two analyses are then linked to give estimates of the microphysical properties of the satellite observed clouds. Examples are given of the application of this technique to derive maps of the probability of occurrence of precipitating clouds and of precipitating water content derived from a case study within the International Cirrus Experiment (ICE) held in 1989 over the North Sea.

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A comparison of the parameterization schemes of fog visibility using the in-situ measurements in the North China Plain

Atmospheric Environment ◽

10.1016/j.atmosenv.2014.03.068 ◽

2014 ◽

Vol 92 ◽

pp. 44-50 ◽

Cited By ~ 2

Author(s):

J. Zhang ◽

H. Xue ◽

Z. Deng ◽

N. Ma ◽

C. Zhao ◽

...

Keyword(s):

North China Plain ◽

North China ◽

In Situ Measurements ◽

Parameterization Schemes ◽

The North ◽

The North China Plain

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An examination of parameterizations for the CCN number concentration based on in situ measurements of aerosol activation properties in the North China Plain

Atmospheric Chemistry and Physics ◽

10.5194/acp-13-6227-2013 ◽

2013 ◽

Vol 13 (13) ◽

pp. 6227-6237 ◽

Cited By ~ 35

Author(s):

Z. Z. Deng ◽

C. S. Zhao ◽

N. Ma ◽

L. Ran ◽

G. Q. Zhou ◽

...

Keyword(s):

Particle Number ◽

Cloud Condensation Nuclei ◽

Number Concentration ◽

In Situ Measurements ◽

Chemical Compositions ◽

Good Prediction ◽

Size Distributions ◽

The North ◽

Aerosol Activation

Abstract. Precise quantification of the cloud condensation nuclei (CCN) number concentration is crucial for understanding aerosol indirect effects and characterizing these effects in models. An evaluation of various methods for CCN parameterization was carried out in this paper based on in situ measurements of aerosol activation properties within HaChi (Haze in China) project. Comparisons were made by closure studies between methods using CCN spectra, bulk activation ratios, cut-off diameters and size-resolved activation ratios. The estimation of CCN number concentrations by the method using aerosol size-resolved activation ratios, either averaged over a day or with diurnal variation, was found to be most satisfying and straightforward. This could be well expected since size-resolved activation ratios include information regarding the effects of size-resolved chemical compositions and mixing states on aerosol activation properties. The method using the averages of critical diameters, which were inferred from measured CCN number concentrations and particle number size distributions, also provided a good prediction of the CCN number concentration. Based on comparisons of all these methods in this paper, it was recommended that the CCN number concentration be predicted using particle number size distributions with inferred critical diameters or size-resolved activation ratios.

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Model-based aviation advice on distal volcanic ash clouds by assimilating aircraft in-situ measurements

10.5194/acp-2016-166 ◽

2016 ◽

Author(s):

G. Fu ◽

A. W. Heemink ◽

S. Lu ◽

A. J. Segers ◽

K. Weber ◽

...

Keyword(s):

Volcanic Ash ◽

Transport Model ◽

Real Life ◽

Forecast Accuracy ◽

In Situ Measurements ◽

North West ◽

The North ◽

Ash Plume ◽

Potential Improvement

Abstract. The forecast accuracy of distal volcanic ash clouds is important for providing valid aviation advice during volcanic ash eruption. However, because the distal part of volcanic ash plume is far from the volcano, the influence of eruption information on this part becomes rather indirect and uncertain, resulting in inaccurate volcanic ash forecasts in these distal areas. In our approach, we use real-life aircraft in-situ observations, measured in the North-West part of Germany during the 2010 Eyjafjallajokull eruption, in an ensemble-based data assimilation system combined with a volcanic ash transport model to investigate the potential improvement on the forecast accuracy with regard to the distal volcanic ash plume. We show that the error of the analyzed volcanic ash state can be significantly reduced through assimilating real-life in-situ measurements. After a continuous assimilation, it is shown that the aviation advice for Germany, the Netherlands and Belgium can be significantly improved. We suggest that with suitable aircrafts measuring once per day across the distal volcanic ash plume, the description and prediction of volcanic ash clouds in these areas can be greatly improved.

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