Consistency of surface anisotropy characterization with meteosat observations

Author(s):
Lattanzio, A.; Govaerts, Y.M.; Pinty, B.
Publication title: Advances in Space Research
2007
 | Volume: 39 | Issue: 1
2007
DOI: 10.1016/j.asr.2006.02.049
Abstract:
The purpose of this paper is to present the results of the evaluation of the Meteosat Surface Albedo (MSA) product, including the effects due to instr… The purpose of this paper is to present the results of the evaluation of the Meteosat Surface Albedo (MSA) product, including the effects due to instrument changes and associated calibration uncertainties. To this end, observations acquired by two adjacent geostationary spacecrafts, Meteosat-7 and Meteosat-5 have been processed with the MSA algorithm. These satellites are located, respectively, at 0° and 63° East. Data acquired by these two instruments overlap over a large area encompassing most of Africa and the Arabian peninsula. The consistency of the surface anisotropy retrieval is evaluated through a reconstruction of the Meteosat-5 (-7) observations with the Meteosat-7 (-5) surface anisotropy characterization. Some differences slightly higher than the calibration accuracy have been found. This effect has no significant impact on the albedo retrieval which indicates that MSA is a reliable algorithm to produce albedo datasets. more
Climate Data Records EUM-Secr Method

Contrasting extremely warm and long-lasting cold air anomalies in the North Atlantic sector of the Arctic during the HALO-(AC)3 campaign

Author(s):
Walbröl, A.; Michaelis, J.; Becker, S.; Dorff, H.; Ebell, K.; Gorodetskaya, I.; Heinold, B.; Kirbus, B.; Lauer, M.; Maherndl, N.; Maturilli, M.; Mayer, J.; Müller, H.; Neggers, R.A.J.; Paulus, F.M.; Röttenbacher, J.; Rückert, J.E.; Schirmacher, I.; Slättberg, N.; Ehrlich, A.; Wendisch, M.; Crewell, S.
Publication title: Atmospheric Chemistry and Physics
2024
 | Volume: 24 | Issue: 13
2024
DOI: 10.5194/acp-24-8007-2024
Abstract:
How air masses transform during meridional transport into and out of the Arctic is not well represented by numerical models. The airborne field campai… How air masses transform during meridional transport into and out of the Arctic is not well represented by numerical models. The airborne field campaign HALO-(AC)3 applied the High Altitude and Long-range Research Aircraft (HALO) within the framework of the collaborative research project on Arctic amplification (AC)3 to address this question by providing a comprehensive observational basis. The campaign took place from 7 March to 12 April 2022 in the North Atlantic sector of the Arctic, a main gateway of atmospheric transport into and out of the Arctic. Here, we investigate to which degree the meteorological and sea ice conditions during the campaign align with the long-term climatology (1979–2022). For this purpose, we use the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis v5 (ERA5), satellite data, and measurements at Ny-Ålesund, including atmospheric soundings. The observations and reanalysis data revealed two distinct periods with different weather conditions during HALO-(AC)3: the campaign started with a warm period (11–20 March 2022) where strong southerly winds prevailed that caused poleward transport of warm and moist air masses, so-called moist and warm air intrusions (WAIs). Two WAI events were identified as atmospheric rivers (ARs), which are narrow bands of strong moisture transport. These warm and moist air masses caused the highest measured 2 m temperatures (5.5 °C) and daily precipitation rates (42 mm d−1) at Ny-Ålesund for March since the beginning of the record (1993). Over the sea ice northwest of Svalbard, ERA5 indicated record-breaking rainfall. After the passage of a strong cyclone on 21 March 2022, a cold period followed. Northerly winds advected cold air into the Fram Strait, causing marine cold air outbreaks (MCAOs) until the end of the campaign. This second phase included one of the longest MCAO events found in the ERA5 record (19 d). On average, the entire campaign period was warmer than the climatological mean due to the strong influence of the ARs. In the Fram Strait, the sea ice concentration was well within the climatological variability over the entire campaign duration. However, during the warm period, a large polynya opened northeast of Svalbard, untypical for this season. Compared to previous airborne field campaigns focusing on the evolution of (mixed-phase) clouds, a larger variety of MCAO conditions was observed during HALO-(AC)3. In summary, air mass transport into and out of the Arctic was more pronounced than usual, providing exciting prospects for studying air mass transformation using HALO-(AC)3 © Author(s) 2024. This work is distributed under the Creative Commons Attribution 4.0 License. more
Application Climate Data Records Cryosphere OSI-SAF

Convection-Permitting ICON-LAM Simulations for Renewable Energy Potential Estimates Over Southern Africa

Author(s):
Chen, S.; Poll, S.; Hendricks Franssen, H.-J.; Heinrichs, H.; Vereecken, H.; Goergen, K.
Publication title: Journal of Geophysical Research: Atmospheres
2024
 | Volume: 129 | Issue: 6
2024
DOI: 10.1029/2023JD039569
Abstract:
Renewable energy is recognized in Africa as a means for climate change mitigation, but also to provide access to electricity in sub-Saharan Africa, wh… Renewable energy is recognized in Africa as a means for climate change mitigation, but also to provide access to electricity in sub-Saharan Africa, where three-quarters of the global population without electricity resides. Reliable and highly resolved renewable energy potential (REP) information is indispensable to support power plants expansion. Existing atmospheric data sets over Africa that are used for REP estimates are often characterized by data gaps, or coarse resolution. With the aim to overcome these challenges, the ICOsahedral Nonhydrostatic (ICON) Numerical Weather Prediction (ICON-NWP) model in its Limited Area Mode (ICON-LAM) is implemented and run over southern Africa in a hindcast dynamical downscaling setup at a convection-permitting 3.3 km horizontal resolution. The simulation time span covers contrasting solar and wind weather years from 2017 to 2019. To assess the suitability of the novel simulations for REP estimates, the simulated hourly 10 m wind speed (sfcWind) and hourly surface solar irradiance (rsds) are extensively evaluated against a large compilation of in situ observations, satellite, and composite data products. ICON-LAM reproduces the spatial patterns, temporal evolution, the variability, and absolute values of sfcWind sufficiently well, albeit with a slight overestimation and a mean bias (mean error (ME)) of 1.12 m s−1 over land. Likewise the simulated rsds with an ME of 50 W m−2 well resembles the observations. This new ICON simulation data product will be the basis for ensuing REP estimates that will be compared with existing lower resolution data sets. © 2024. The Authors. more
Application Atmosphere CM-SAF Climate Data Records Validation

Contribution of changes in snow cover extent to shortwave radiation perturbations at the top of the atmosphere over the northern hemisphere during 2000–2019

Author(s):
Chen, X.; Yang, Y.; Yin, C.
Publication title: Remote Sensing
2021
 | Volume: 13 | Issue: 23
2021
DOI: 10.3390/rs13234938
Abstract:
Snow-induced radiative forcing (SnRF), defined as the instantaneous perturbation of the Earth’s shortwave radiation at the top of the atmosphere (TOA)… Snow-induced radiative forcing (SnRF), defined as the instantaneous perturbation of the Earth’s shortwave radiation at the top of the atmosphere (TOA), results from variations in the terrestrial snow cover extent (SCE), and is critical for the regulation of the Earth’s energy budget. However, with the growing seasonal divergence of SCE over the Northern Hemisphere (NH) in the past two decades, novel insights pertaining to SnRF are lacking. Consequently, the contribution of SnRF to TOA shortwave radiation anomalies still remains unclear. Utilizing the latest datasets of snow cover, surface albedo, and albedo radiative kernels, this study investigated the distribution of SnRF over the NH and explored its changes from 2000 to 2019. The 20-year averaged annual mean SnRF in the NH was −1.13 ± 0.05 W m−2, with a weakening trend of 0.0047 Wm−2 yr−1 (p < 0.01) during 2000–2019, indicating that an extra 0.094 W m−2 of shortwave radiation was absorbed by the Earth climate system. Moreover, changes in SnRF were highly correlated with satellite-observed TOA shortwave flux anomalies (r = 0.79, p < 0.05) during 2000–2019. Additionally, a detailed contribution analysis revealed that the SnRF in snow accumulation months, from March to May, accounted for 58.10% of the annual mean SnRF variability across the NH. These results can assist in providing a better understanding of the role of snow cover in Earth’s climate system in the context of climate change. Although the rapid SCE decline over the NH has a hiatus for the period during 2000–2019, SnRF continues to follow a weakening trend. Therefore, this should be taken into consideration in current climate change models and future climate projections. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. more
Application CM-SAF Climate Data Records Cryosphere

Contributions to the Improvement of Climate Data Availability and Quality for Sub-Saharan Africa

Author(s):
Kaspar, F.; Andersson, A.; Ziese, M.; Hollmann, R.
Publication title: Frontiers in Climate
2022
 | Volume: 3
2022
DOI: 10.3389/fclim.2021.815043
Abstract:
Reliable weather observations are the basis to assess climate change and variability. Compared to other regions of the world, long time series of weat… Reliable weather observations are the basis to assess climate change and variability. Compared to other regions of the world, long time series of weather observations are sparse in many countries of Sub-Saharan Africa. Various activities at national or international level are ongoing to improve the availability and quality of climate databases. Here, we present ongoing international contributions with a focus on representative examples hosted at Germany's national meteorological service DWD (Deutscher Wetterdienst). The international exchange of monthly climate reports (CLIMAT) is monitored within the Monitoring Centre of the GCOS Surface Network (Global Climate Observing System). In that context also quality control is performed and data are made publicly available. Recent climate observations can be complemented by digitization of historical hand-written weather observations which are available in distributed archives. International data centers, such as the Global Precipitation Climatology Centre (GPCC), collect international data. They perform quality-control of these observations and provide derived products in support of global and regional climate assessments. These activities can also contribute to the improvement of national climate databases, as e.g., demonstrated in a cooperation among selected countries with the SASSCAL initiative (Southern African Science Service Centre for Climate Change and Adaptive Land Management). Satellite-based observations are an additional source that can provide climatological information for selected parameters. In particular, the METEOSAT satellite series provides valuable data for the African continent. The Satellite Application Facility on Climate Monitoring (CM SAF) provides high resolution climate data covering the last decades derived from observations of such meteorological satellites. Based on these examples the paper illustrates the variety of ongoing international efforts in support of regional observation-based climate information, but also identifies the needs for further activities. Copyright © 2022 Kaspar, Andersson, Ziese and Hollmann. more
Application Atmosphere CM-SAF Climate Data Records

Copernicus Marine Service Ocean State Report, Issue 3

Author(s):
von Schuckmann, Karina; Le Traon, Pierre-Yves; Smith, Neville; Pascual, Ananda; Djavidnia, Samuel; Gattuso, Jean-Pierre; Grégoire, Marilaure; Nolan, Glenn; Aaboe, Signe; Aguiar, Eva; Álvarez Fanjul, Enrique; Alvera-Azcárate, Aida; Aouf, Lotfi; Barciela, Rosa; Behrens, Arno; Belmonte Rivas, Maria; Ben Ismail, Sana; Bentamy, Abderrahim; Borgini, Mireno; Brando, Vittorio E.; Bensoussan, Nathaniel; Blauw, Anouk; Bryère, Philippe; Buongiorno Nardelli, Bruno; Caballero, Ainhoa; Çağlar Yumruktepe, Veli; Cebrian, Emma; Chiggiato, Jacopo; Clementi, Emanuela; Corgnati, Lorenzo; de Alfonso, Marta; de Pascual Collar, Álvaro; Deshayes, Julie; Di Lorenzo, Emanuele; Dominici, Jean-Marie; Dupouy, Cécile; Drévillon, Marie; Echevin, Vincent; Eleveld, Marieke; Enserink, Lisette; García Sotillo, Marcos; Garnesson, Philippe; Garrabou, Joaquim; Garric, Gilles; Gasparin, Florent; Gayer, Gerhard; Gohin, Francis; Grandi, Alessandro; Griffa, Annalisa; Gourrion, Jérôme; Hendricks, Stefan; Heuzé, Céline; Holland, Elisabeth; Iovino, Doroteaciro; Juza, Mélanie; Kurt Kersting, Diego; Kipson, Silvija; Kizilkaya, Zafer; Korres, Gerasimos; Kõuts, Mariliis; Lagemaa, Priidik; Lavergne, Thomas; Lavigne, Heloise; Ledoux, Jean-Baptiste; Legeais, Jean-François; Lehodey, Patrick; Linares, Cristina; Liu, Ye; Mader, Julien; Maljutenko, Ilja; Mangin, Antoine; Manso-Narvarte, Ivan; Mantovani, Carlo; Markager, Stiig; Mason, Evan; Mignot, Alexandre; Menna, Milena; Monier, Maeva; Mourre, Baptiste; Müller, Malte; Nielsen, Jacob Woge; Notarstefano, Giulio; Ocaña, Oscar; Pascual, Ananda; Patti, Bernardo; Payne, Mark R.; Peirache, Marion; Pardo, Silvia; Pérez Gómez, Begoña; Pisano, Andrea; Perruche, Coralie; Peterson, K. Andrew; Pujol, Marie-Isabelle; Raudsepp, Urmas; Ravdas, Michalis; Raj, Roshin P.; Renshaw, Richard; Reyes, Emma; Ricker, Robert; Rubio, Anna; Sammartino, Michela; Santoleri, Rosalia; Sathyendranath, Shubha; Schroeder, Katrin; She, Jun; Sparnocchia, Stefania; Staneva, Joanna; Stoffelen, Ad; Szekely, Tanguy; Tilstone, Gavin H.; Tinker, Jonathan; Tintoré, Joaquín; Tranchant, Benoît; Uiboupin, Rivo; Van der Zande, Dimitry; von Schuckmann, Karina; Wood, Richard; Woge Nielsen, Jacob; Zabala, Mikel; Zacharioudaki, Anna; Zuberer, Frédéric; Zuo, Hao
Publication title: Journal of Operational Oceanography
2019
 | Volume: 12 | Issue: sup1
2019
DOI: 10.1080/1755876X.2019.1633075
Application Climate Data Records Cryosphere OSI-SAF

Coral Skeletal Luminescence Records Changes in Terrestrial Chromophoric Dissolved Organic Matter in Tropical Coastal Waters

Author(s):
Kaushal, N.; Sanwlani, N.; Tanzil, J.T.I.; Cherukuru, N.; Sahar, S.; Müller, M.; Mujahid, A.; Lee, J.N.; Goodkin, N.F.; Martin, P.
Publication title: Geophysical Research Letters
2021
 | Volume: 48 | Issue: 8
2021
DOI: 10.1029/2020GL092130
Abstract:
Terrigenous dissolved organic matter (tDOM) carried by rivers represents an important carbon flux to the coastal ocean, which is thought to be increas… Terrigenous dissolved organic matter (tDOM) carried by rivers represents an important carbon flux to the coastal ocean, which is thought to be increasing globally. Because tDOM is rich in light-absorbent chromophoric dissolved organic matter (CDOM), it may also reduce the amount of sunlight available in coastal ecosystems. Despite its biogeochemical and ecological significance, there are few long-term records of tDOM, hindering our understanding of its drivers and dynamics. Corals incorporate terrestrial humic acids, an important constituent of CDOM, resulting in luminescent bands that have been previously linked to rainfall and run-off. We show that luminescence green-to-blue (G/B) ratios in a coral core growing in waters affected by peatland run-off correlate strongly with remote sensing-derived CDOM absorption. The 24-year monthly resolution reconstructed record shows that rainfall controls land-to-ocean tDOM flux from this protected peatland catchment, and suggests an additional impact by solar radiation, which degrades tDOM at sea. © 2021. The Authors. more
Application Atmosphere CM-SAF Climate Data Records Ocean

Coupling Diffuse Sky Radiation and Surface Albedo

Author(s):
Pinty, Bernard; Lattanzio, Alessio; Martonchik, John V.; Verstraete, Michel M.; Gobron, Nadine; Taberner, Malcolm; Widlowski, Jean-Luc; Dickinson, Robert E.; Govaerts, Yves
Publication title: Journal of the Atmospheric Sciences
2005
 | Volume: 62 | Issue: 7
2005
DOI: 10.1175/JAS3479.1
Abstract:
Abstract New satellite instruments have been delivering a wealth of information regarding land surface albedo. This basic quantity describ… Abstract New satellite instruments have been delivering a wealth of information regarding land surface albedo. This basic quantity describes what fraction of solar radiation is reflected from the earth’s surface. However, its concept and measurements have some ambiguity resulting from its dependence on the incidence angles of both the direct and diffuse solar radiation. At any time of day, a surface receives direct radiation in the direction of the sun, and diffuse radiation from the various other directions in which it may have been scattered by air molecules, aerosols, and cloud droplets. This contribution proposes a complete description of the distribution of incident radiation with angles, and the implications in terms of surface albedo are given in a mathematical form, which is suitable for climate models that require evaluating surface albedo many times. The different definitions of observed albedos are explained in terms of the coupling between surface and atmospheric scattering properties. The analytical development in this paper relates the various quantities that are retrieved from orbiting platforms to what is needed by an atmospheric model. It provides a physically simple and practical approach to evaluation of land surface albedo values at any condition of sun illumination irrespective of the current range of surface anisotropic conditions and atmospheric aerosol load. The numerical differences between the various definitions of albedo for a set of typical atmospheric and surface scattering conditions are illustrated through numerical computation. more
Climate Data Records EUM-Secr Land Method

Coupling the regional climate model ICON-CLM v2.6.6 to the Earth system model GCOAST-AHOI v2.0 using OASIS3-MCT v4.0

Author(s):
Ho-Hagemann, H.T.M.; Maurer, V.; Poll, S.; Fast, I.
Publication title: Geoscientific Model Development
2024
 | Volume: 17 | Issue: 21
2024
DOI: 10.5194/gmd-17-7815-2024
Abstract:
Interactions and feedback between components of the Earth system can have a significant impact on local and regional climate and its changes due to gl… Interactions and feedback between components of the Earth system can have a significant impact on local and regional climate and its changes due to global warming. These effects can be better represented by regional Earth system models (RESMs) than by traditional stand-alone atmosphere and ocean models. Here, we present the RESM Geesthacht Coupled cOAstal model SysTem (GCOAST)-AHOI v2.0, which includes a new atmospheric component, the regional climate model Icosahedral Nonhydrostatic (ICON)-CLM, which is coupled to the Nucleus for European Modelling of the Ocean (NEMO) and the hydrological discharge model HD via the OASIS3-MCT coupler. The GCOAST-AHOI model has been developed and applied for climate simulations over the EURO-CORDEX domain. Two 11-year simulations from 2008 to 2018 of the uncoupled ICON-CLM and GCOAST-AHOI give similar results for seasonal and annual means of near-surface air temperature, precipitation, mean sea level pressure, and wind speed at a height of 10 m. However, GCOAST-AHOI has a cold sea surface temperature (SST) bias of 1-2 K over the Baltic and North seas that is most pronounced in the winter and spring seasons. A possible reason for the cold SST bias could be the underestimation of the downward shortwave radiation at the surface of ICON-CLM with the current model settings. Despite the cold SST bias, GCOAST-AHOI was able to capture other key variables well, such as those mentioned above. Therefore, GCOAST-AHOI can be a useful tool for long-term climate simulations over the EURO-CORDEX domain. Compared to the stand-alone NEMO3.6 forced by ERA5 and ORAS5 boundary forcing, GCOAST-AHOI has positive biases in sea ice fraction and salinity but negative biases in runoff, which need to be investigated further in the future to improve the coupled simulations. The new OASIS3-MCT coupling interface OMCI implemented in ICON-CLM adds the possibility of coupling ICON-CLM to an external ocean model and an external hydrological discharge model using OASIS3-MCT instead of the YAC (Yet Another Coupler). Using OMCI, it is also possible to set up a RESM with ICON-CLM and other ocean and hydrology models possessing the OASIS3-MCT interface for other regions, such as the Mediterranean Sea. Copyright: © 2024 Ha Thi Minh Ho-Hagemann et al. more
Application Atmosphere CM-SAF Climate Data Records Validation
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