Characterizing precipitation in convective cloud regimes in the trades with the polarimetric C-band radar POLDIRAD

Low-level clouds in the trade regions play an important role in the Earth&#8217;s climate system since they have a considerable influence on the Earth&#8217;s radiation budget. However, the understanding of the coupling between cloud dynamics, cloud microphysics, and mesoscale organization is limited. This results in a large uncertainty in current climate predictions. Despite the importance, observations in these regions are limited. Geostationary satellites cannot provide high resolution three-dimensional details of clouds and precipitation. Polar orbiting satellites like the A-Train satellites Cloudsat and Calipso or the upcoming EarthCARE satellite do provide detailed profiles of cloud properties, but the temporal evolution cannot be observed. On the other hand, long range weather radar observations can provide both, high spatial and temporal observations, however not many weather radar do cover the trades.During the Eurec4a campaign DLRs C-band polarimetric weather radar POLDIRAD was installed on the island of Barbados. The scope of the radar measurements is manifold:- POLDIRAD will provide high resolution observations of the different mesoscale cloud patterns as observed from satellites: Flowers, Gravel, Fish, and Sugar. Will the mesoscale organization have an influence on observable microphysical properties?- POLDIRAD will put the detailed measurements by aircraft (in situ and remote sensing) into a greater context. How are the aircraft measurements related to the spatial distribution of the precipitation pattern? How are the aircraft measurements related to the temporal evolution of the precipitation pattern?- POLDIRAD will put the observed profiles of clouds and precipitation at the Barbados Cloud Observatory BCO at Deebles Point into a greater context. How are the profile measurements related to the spatial distribution of the precipitation pattern? How are the profile measurements related to the temporal evolution of the precipitation pattern?

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The impact of cloud inhomogeneities on the Earth radiation budget: the 14 October 1989 I.C.E. convective cloud case study

Annales Geophysicae ◽

10.1007/s00585-994-0240-z ◽

1994 ◽

Vol 12 (2/3) ◽

pp. 240-253 ◽

Cited By ~ 1

Author(s):

F. Parol ◽

J. C. Buriez ◽

D. Crétel ◽

Y. Fouquart

Keyword(s):

Aspect Ratio ◽

Water Content ◽

Liquid Water ◽

Convective Cloud ◽

Liquid Water Content ◽

Radiation Budget ◽

The Earth ◽

Earth Radiation Budget ◽

The Impact ◽

Earth Radiation

Abstract. Through their multiple interactions with radiation, clouds have an important impact on the climate. Nonetheless, the simulation of clouds in climate models is still coarse. The present evolution of modeling tends to a more realistic representation of the liquid water content; thus the problem of its subgrid scale distribution is crucial. For a convective cloud field observed during ICE 89, Landsat TM data (resolution: 30m) have been analyzed in order to quantify the respective influences of both the horizontal distribution of liquid water content and cloud shape on the Earth radiation budget. The cloud field was found to be rather well-represented by a stochastic distribution of hemi-ellipsoidal clouds whose horizontal aspect ratio is close to 2 and whose vertical aspect ratio decreases as the cloud cell area increases. For that particular cloud field, neglecting the influence of the cloud shape leads to an over-estimate of the outgoing longwave flux; in the shortwave, it leads to an over-estimate of the reflected flux for high solar elevations but strongly depends on cloud cell orientations for low elevations. On the other hand, neglecting the influence of cloud size distribution leads to systematic over-estimate of their impact on the shortwave radiation whereas the effect is close to zero in the thermal range. The overall effect of the heterogeneities is estimated to be of the order of 10 W m-2 for the conditions of that Landsat picture (solar zenith angle 65°, cloud cover 70%); it might reach 40 W m-2 for an overhead sun and overcast cloud conditions.

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Development of the HIRS Outgoing Longwave Radiation Climate Dataset

Journal of Atmospheric and Oceanic Technology ◽

10.1175/2007jtecha989.1 ◽

2007 ◽

Vol 24 (12) ◽

pp. 2029-2047 ◽

Cited By ~ 61

Author(s):

Hai-Tien Lee ◽

Arnold Gruber ◽

Robert G. Ellingson ◽

Istvan Laszlo

Keyword(s):

Time Series ◽

High Resolution ◽

Outgoing Longwave Radiation ◽

Longwave Radiation ◽

Radiation Budget ◽

Validation Data ◽

The Earth ◽

Data Record ◽

Earth Radiation Budget ◽

Earth Radiation

Abstract The Advanced Very High Resolution Radiometer (AVHRR) outgoing longwave radiation (OLR) product, which NOAA has been operationally generating since 1979, is a very long data record that has been used in many applications, yet past studies have shown its limitations and several algorithm-related deficiencies. Ellingson et al. have developed the multispectral algorithm that largely improved the accuracy of the narrowband-estimated OLR as well as eliminated the problems in AVHRR. NOAA has been generating High Resolution Infrared Radiation Sounder (HIRS) OLR operationally since September 1998. In recognition of the need for a continuous and long OLR data record that would be consistent with the earth radiation budget broadband measurements in the National Polar-orbiting Operational Environmental Satellite System (NPOESS) era, and to provide a climate data record for global change studies, a vigorous reprocessing of the HIRS radiance for OLR derivation is necessary. This paper describes the development of the new HIRS OLR climate dataset. The HIRS level 1b data from the entire Television and Infrared Observation Satellite N-series (TIROS-N) satellites have been assembled. A new radiance calibration procedure was applied to obtain more accurate and consistent HIRS radiance measurements. The regression coefficients of the HIRS OLR algorithm for all satellites were rederived from calculations using an improved radiative transfer model. Intersatellite calibrations were performed to remove possible discontinuity in the HIRS OLR product from different satellites. A set of global monthly diurnal models was constructed consistent with the HIRS OLR retrievals to reduce the temporal sampling errors and to alleviate an orbital-drift-induced artificial trend. These steps significantly improved the accuracy, continuity, and uniformity of the HIRS monthly mean OLR time series. As a result, the HIRS OLR shows a comparable stability as in the Earth Radiation Budget Satellite (ERBS) nonscanner OLR measurements. HIRS OLR has superb agreement with the broadband observations from Earth Radiation Budget Experiment (ERBE) and Clouds and the Earth’s Radiant Energy System (CERES) in the ENSO-monitoring regions. It shows compatible ENSO-monitoring capability with the AVHRR OLR. Globally, HIRS OLR agrees with CERES with an accuracy to within 2 W m−2 and a precision of about 4 W m−2. The correlation coefficient between HIRS and CERES global monthly mean is 0.997. Regionally, HIRS OLR agrees with CERES to within 3 W m−2 with precisions better than 3 W m−2 in most places. HIRS OLR could be used for constructing climatology for applications that plan to use NPOESS ERBS and previously used AVHRR OLR observations. The HIRS monthly mean OLR data have high accuracy and precision with respect to the broadband observations of ERBE and CERES. It can be used as an independent validation data source. The uniformity and continuity of HIRS OLR time series suggest that it could be used as a reliable transfer reference for the discontinuous broadband measurements from ERBE, CERES, and ERBS.

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The impact of cloud inhomogeneities on the Earth radiation budget: the 14 October 1989 I.C.E. convective cloud case study

Annales Geophysicae ◽

10.1007/s005850050054 ◽

1994 ◽

Vol 12 (2) ◽

pp. 240

Author(s):

F. Parol ◽

J. C. Buriez ◽

D. Crétel ◽

Y. Fouquart

Keyword(s):

Convective Cloud ◽

Radiation Budget ◽

The Earth ◽

Earth Radiation Budget ◽

The Impact ◽

Earth Radiation

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Gridded Population Maps Informed by Different Built Settlement Products

Data ◽

10.3390/data3030033 ◽

2018 ◽

Vol 3 (3) ◽

pp. 33 ◽

Cited By ~ 18

Author(s):

Fennis Reed ◽

Andrea Gaughan ◽

Forrest Stevens ◽

Greg Yetman ◽

Alessandro Sorichetta ◽

...

Keyword(s):

Spatial Distribution ◽

High Resolution ◽

Random Forest ◽

Hybrid Models ◽

Population Estimates ◽

Spatially Explicit ◽

Human Populations ◽

Critical Knowledge ◽

The Earth ◽

Modeling Techniques

The spatial distribution of humans on the earth is critical knowledge that informs many disciplines and is available in a spatially explicit manner through gridded population techniques. While many approaches exist to produce specialized gridded population maps, little has been done to explore how remotely sensed, built-area datasets might be used to dasymetrically constrain these estimates. This study presents the effectiveness of three different high-resolution built area datasets for producing gridded population estimates through the dasymetric disaggregation of census counts in Haiti, Malawi, Madagascar, Nepal, Rwanda, and Thailand. Modeling techniques include a binary dasymetric redistribution, a random forest with a dasymetric component, and a hybrid of the previous two. The relative merits of these approaches and the data are discussed with regards to studying human populations and related spatially explicit phenomena. Results showed that the accuracy of random forest and hybrid models was comparable in five of six countries.

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Reexamination of the Observed Decadal Variability of the Earth Radiation Budget Using Altitude-Corrected ERBE/ERBS Nonscanner WFOV Data

Journal of Climate ◽

10.1175/jcli3838.1 ◽

2006 ◽

Vol 19 (16) ◽

pp. 4028-4040 ◽

Cited By ~ 109

Author(s):

Takmeng Wong ◽

Bruce A. Wielicki ◽

Robert B. Lee ◽

G. Louis Smith ◽

Kathryn A. Bush ◽

...

Keyword(s):

High Resolution ◽

Decadal Variability ◽

Radiation Budget ◽

Wide Field ◽

Net Radiation ◽

The Earth ◽

Time Period ◽

Data User ◽

Earth Radiation Budget ◽

Earth Radiation

Abstract This paper gives an update on the observed decadal variability of the earth radiation budget (ERB) using the latest altitude-corrected Earth Radiation Budget Experiment (ERBE)/Earth Radiation Budget Satellite (ERBS) Nonscanner Wide Field of View (WFOV) instrument Edition3 dataset. The effects of the altitude correction are to modify the original reported decadal changes in tropical mean (20°N to 20°S) longwave (LW), shortwave (SW), and net radiation between the 1980s and the 1990s from 3.1, −2.4, and −0.7 to 1.6, −3.0, and 1.4 W m−2, respectively. In addition, a small SW instrument drift over the 15-yr period was discovered during the validation of the WFOV Edition3 dataset. A correction was developed and applied to the Edition3 dataset at the data user level to produce the WFOV Edition3_Rev1 dataset. With this final correction, the ERBS Nonscanner-observed decadal changes in tropical mean LW, SW, and net radiation between the 1980s and the 1990s now stand at 0.7, −2.1, and 1.4 W m−2, respectively, which are similar to the observed decadal changes in the High-Resolution Infrared Radiometer Sounder (HIRS) Pathfinder OLR and the International Satellite Cloud Climatology Project (ISCCP) version FD record but disagree with the Advanced Very High Resolution Radiometer (AVHRR) Pathfinder ERB record. Furthermore, the observed interannual variability of near-global ERBS WFOV Edition3_Rev1 net radiation is found to be remarkably consistent with the latest ocean heat storage record for the overlapping time period of 1993 to 1999. Both datasets show variations of roughly 1.5 W m−2 in planetary net heat balance during the 1990s.

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Modelling study on the formation of pockets of open cells in marine stratocumulus cloud during CLARIFY

10.5194/egusphere-egu2020-16043 ◽

2020 ◽

Author(s):

Emma Simpson ◽

Tom Choularton

Keyword(s):

Cloud Model ◽

Direct Interaction ◽

Cloud Microphysics ◽

Large Eddy Simulations ◽

Radiation Budget ◽

Microphysics Scheme ◽

Marine Stratocumulus ◽

Open Cell ◽

The Earth ◽

Large Eddy

Due to the wide spread nature of marine stratocumulus cloud they have a significant impact on the Earth&#8217;s radiation budget. Such clouds are sensitive to the presence of aerosol, which can promote the break-up of a cloud deck into pockets of open cell convection (POC). The transition from a cloud deck to pockets of open cells changes the overall cloud albedo thus affecting the Earth&#8217;s radiation budget. The representation of stratocumulus cloud and the transition to POCs is poorly represented in current climate and weather models. This study aims to improve understanding of this process using extensive in-situ measurements made during the CLARIFY campaign of stratocumulus cloud decks, transition areas between overcast and open cell cloud structures as well as areas of POCs, to inform and compare to large-eddy simulations.A variety of different aerosol situations occurred during CLARIFY, combinations of polluted/clean boundary layer and polluted/clean conditions above the cloud layer. Large-eddy simulations are conducted to investigate the sensitivity of clouds to changes in the observed aerosol conditions with a particular focus on whether or not the change in aerosol initiates cloud breakup.The MetOffice NERC Cloud model (MONC) is used to preform the large-eddy simulations and employs the CASIM cloud microphysics scheme which includes activation of aerosol particles to cloud drops. Such a model set-up allows direct interaction between aerosols and clouds. Observations from CLARIFY are used to initialise and evaluate model simulations.

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Ultrastructural analysis of the spatial distribution of MRNA

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100123167 ◽

1992 ◽

Vol 50 (1) ◽

pp. 552-553

Author(s):

Gary Bassell ◽

Robert H. Singer

Keyword(s):

Electron Microscopy ◽

Spatial Distribution ◽

In Situ Hybridization ◽

High Resolution ◽

Nucleic Acids ◽

Colloidal Gold ◽

Dna Probe ◽

Nucleotide Analogs ◽

Gold Particles

We have been investigating the spatial distribution of nucleic acids intracellularly using in situ hybridization. The use of non-isotopic nucleotide analogs incorporated into the DNA probe allows the detection of the probe at its site of hybridization within the cell. This approach therefore is compatible with the high resolution available by electron microscopy. Biotinated or digoxigenated probe can be detected by antibodies conjugated to colloidal gold. Because mRNA serves as a template for the probe fragments, the colloidal gold particles are detected as arrays which allow it to be unequivocally distinguished from background.

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Global model simulations of the impact of ocean-going ships on aerosols, clouds, and the radiation budget

Atmospheric Chemistry and Physics ◽

10.5194/acp-7-5061-2007 ◽

2007 ◽

Vol 7 (19) ◽

pp. 5061-5079 ◽

Cited By ~ 146

Author(s):

A. Lauer ◽

V. Eyring ◽

J. Hendricks ◽

P. Jöckel ◽

U. Lohmann

Keyword(s):

Particulate Matter ◽

Chemical Composition ◽

Optical Thickness ◽

Emission Inventory ◽

Cloud Microphysics ◽

Number Concentration ◽

Climate Impacts ◽

Aerosol Optical Thickness ◽

Radiation Budget ◽

International Shipping

Abstract. International shipping contributes significantly to the fuel consumption of all transport related activities. Specific emissions of pollutants such as sulfur dioxide (SO2) per kg of fuel emitted are higher than for road transport or aviation. Besides gaseous pollutants, ships also emit various types of particulate matter. The aerosol impacts the Earth's radiation budget directly by scattering and absorbing the solar and thermal radiation and indirectly by changing cloud properties. Here we use ECHAM5/MESSy1-MADE, a global climate model with detailed aerosol and cloud microphysics to study the climate impacts of international shipping. The simulations show that emissions from ships significantly increase the cloud droplet number concentration of low marine water clouds by up to 5% to 30% depending on the ship emission inventory and the geographic region. Whereas the cloud liquid water content remains nearly unchanged in these simulations, effective radii of cloud droplets decrease, leading to cloud optical thickness increase of up to 5–10%. The sensitivity of the results is estimated by using three different emission inventories for present-day conditions. The sensitivity analysis reveals that shipping contributes to 2.3% to 3.6% of the total sulfate burden and 0.4% to 1.4% to the total black carbon burden in the year 2000 on the global mean. In addition to changes in aerosol chemical composition, shipping increases the aerosol number concentration, e.g. up to 25% in the size range of the accumulation mode (typically >0.1 μm) over the Atlantic. The total aerosol optical thickness over the Indian Ocean, the Gulf of Mexico and the Northeastern Pacific increases by up to 8–10% depending on the emission inventory. Changes in aerosol optical thickness caused by shipping induced modification of aerosol particle number concentration and chemical composition lead to a change in the shortwave radiation budget at the top of the atmosphere (ToA) under clear-sky condition of about −0.014 W/m² to −0.038 W/m² for a global annual average. The corresponding all-sky direct aerosol forcing ranges between −0.011 W/m² and −0.013 W/m². The indirect aerosol effect of ships on climate is found to be far larger than previously estimated. An indirect radiative effect of −0.19 W/m² to −0.60 W/m² (a change in the atmospheric shortwave radiative flux at ToA) is calculated here, contributing 17% to 39% of the total indirect effect of anthropogenic aerosols. This contribution is high because ship emissions are released in regions with frequent low marine clouds in an otherwise clean environment. In addition, the potential impact of particulate matter on the radiation budget is larger over the dark ocean surface than over polluted regions over land.

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