scholarly journals Characterization of shallow oceanic precipitation using profiling and scanning radar observations at the Eastern North Atlantic ARM observatory

2019 ◽  
Vol 12 (9) ◽  
pp. 4931-4947 ◽  
Author(s):  
Katia Lamer ◽  
Bernat Puigdomènech Treserras ◽  
Zeen Zhu ◽  
Bradley Isom ◽  
Nitin Bharadwaj ◽  
...  
Keyword(s):  
North Atlantic ◽  
Evaluation Studies ◽  
Precipitation Rate ◽  
Similar Time ◽  
Radar Systems ◽  
Atmospheric Radiation Measurement ◽  
Eastern North Atlantic ◽  
Constant Altitude ◽  
Global Precipitation ◽  
Oceanic Precipitation

Abstract. Shallow oceanic precipitation variability is documented using three second-generation radar systems located at the Atmospheric Radiation Measurement (ARM) Eastern North Atlantic observatory: ARM zenith radar (KAZR2), the Ka-band scanning ARM cloud radar (KaSACR2) and the X-band scanning ARM precipitation radar (XSAPR2). First, the radar systems and measurement post-processing techniques, including sea-clutter removal and calibration against colocated disdrometer and Global Precipitation Mission (GPM) observations are described. Then, we present how a combination of profiling radar and lidar observations can be used to estimate adaptive (in both time and height) parameters that relate radar reflectivity (Z) to precipitation rate (R) in the form Z=αRβ, which we use to estimate precipitation rate over the domain observed by XSAPR2. Furthermore, constant altitude plan position indicator (CAPPI) gridded XSAPR2 precipitation rate maps are also constructed. Hourly precipitation rate statistics estimated from the three radar systems differ because KAZR2 is more sensitive to shallow virga and XSAPR2 suffers from less attenuation than KaSACR2 and as such is best suited for characterizing intermittent and mesoscale-organized precipitation. Further analysis reveals that precipitation rate statistics obtained by averaging 12 h of KAZR2 observations can be used to approximate that of a 40 km radius domain averaged over similar time periods. However, it was determined that KAZR2 is unsuitable for characterizing domain-averaged precipitation rate over shorter periods. But even more fundamentally, these results suggest that these observations cannot produce an objective domain precipitation estimate and that the simultaneous use of forward simulators is desirable to guide model evaluation studies.

scholarly journals Characterization of Shallow Oceanic Precipitation using Profiling and Scanning Radar Observations at the Eastern North Atlantic ARM Observatory

2019 ◽  
Author(s):  
Katia Lamer ◽  
Bernat Puigdomènech Treserras ◽  
Zeen Zhu ◽  
Bradley Isom ◽  
Nitin Bharadwaj ◽  
...  
Keyword(s):  
North Atlantic ◽  
Evaluation Studies ◽  
Precipitation Rate ◽  
High Temporal Resolution ◽  
Similar Time ◽  
Ka Band ◽  
Resolution Model ◽  
Eastern North Atlantic ◽  
Constant Altitude ◽  
Oceanic Precipitation

Abstract. Shallow oceanic precipitation variability is documented using 2nd generation radars located at the Atmospheric Radiation Measurement (ARM) Eastern North Atlantic observatory: the Ka-band ARM zenith radar (KAZR2), the Ka-band scanning ARM cloud radar (KaSACR2) and the X-band scanning ARM precipitation radar (XSAPR2). First, the radars and measurement post-processing techniques, including sea clutter removal and calibration against collocated disdrometer and Global Precipitation Mission (GPM) observations are described. Then, we present how a combination of profiling radar and lidar observations can be used to estimate adaptive (in both time and height) parameters that relate radar reflectivity (Z) to precipitation rate (R) in the form Z = αRβ which we use to estimate precipitation rate over the domain observed by XSAPR2. Furthermore, Constant Altitude Plan Position Indicator (CAPPI) gridded XSAPR2 precipitation rate maps are also constructed. Hourly precipitation rate statistics estimated from the three radars differ; that is because KAZR2 is more sensitive to shallow virga and because XSAPR2 suffers from less attenuation that KaSACR2 and as such is best suited to characterize intermittent and mesoscale-organized precipitation. Further analysis reveals that precipitation rate statistics obtained by averaging 12 h of KAZR2 observations can be used to approximate that of a domain of 2500 km2 averaged over similar time periods. However, it was determined that KAZR2 is unsuitable to characterize domain average precipitation rate over shorter periods. But even more fundamentally, these results suggest that observations cannot produce objective domain precipitation estimate and that forward-simulators should be used to guide high temporal-resolution model evaluation studies.

scholarly journals An Update on the Oceanic Precipitation Rate and Its Zonal Distribution in Light of Advanced Observations from Space

2014 ◽  
Vol 27 (11) ◽  
pp. 3957-3965 ◽  
Author(s):  
Ali Behrangi ◽  
Graeme Stephens ◽  
Robert F. Adler ◽  
George J. Huffman ◽  
Bjorn Lambrigtsen ◽  
...  
Keyword(s):  
Tropical Rainfall Measuring Mission ◽  
High Sensitivity ◽  
Global Precipitation Climatology Project ◽  
Precipitation Rate ◽  
Global Ocean ◽  
Zonal Distribution ◽  
Earth Observing System ◽  
Precipitation Estimates ◽  
Global Precipitation ◽  
Oceanic Precipitation

Abstract This study contributes to the estimation of the global mean and zonal distribution of oceanic precipitation rate using complementary information from advanced precipitation measuring sensors and provides an independent reference to assess current precipitation products. Precipitation estimates from the Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) and CloudSat cloud profiling radar (CPR) were merged, as the two complementary sensors yield an unprecedented range of sensitivity to quantify rainfall from drizzle through the most intense rates. At higher latitudes, where TRMM PR does not exist, precipitation estimates from Aqua’s Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) complemented CloudSat CPR to capture intense precipitation rates. The high sensitivity of CPR allows estimation of snow rate, an important type of precipitation at high latitudes, not directly observed in current merged precipitation products. Using the merged precipitation estimate from the CloudSat, TRMM, and Aqua platforms (this estimate is abbreviated to MCTA), the authors’ estimate for 3-yr (2007–09) near-global (80°S–80°N) oceanic mean precipitation rate is ~2.94 mm day−1. This new estimate of mean global ocean precipitation is about 9% higher than that of the corresponding Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) value (2.68 mm day−1) and about 4% higher than that of the Global Precipitation Climatology Project (GPCP; 2.82 mm day−1). Furthermore, MCTA suggests distinct differences in the zonal distribution of precipitation rate from that depicted in GPCP and CMAP, especially in the Southern Hemisphere.

Remotely-controlled ice-nucleating particle measurements from the Eastern North Atlantic during autumn and winter

2021 ◽  
Author(s):  
Elise Wilbourn ◽  
Naruki Hiranuma ◽  
Larissa Lacher ◽  
Jens Nadolny ◽  
Ottmar Möhler
Keyword(s):  
Boundary Layer ◽  
North Atlantic ◽  
Marine Boundary Layer ◽  
Department Of Energy ◽  
Small Island ◽  
Remote Maintenance ◽  
Atmospheric Radiation Measurement ◽  
Time Of Year ◽  
Eastern North Atlantic ◽  
Heterogeneous Formation

<p>Ice-nucleating particles (INPs) are aerosol particles that catalyze the heterogeneous formation of ice crystals under ice supersaturation conditions. These INPs can change cloud characteristics on wide spatiotemporal scales, including albedo and radiative effects, as well as precipitation types and amounts, thus affecting both weather and climate. However, INP measurements with reasonable temporal resolution have been challenging in terms of both technology and logistics in our research community. Here we present preliminary results of our recent six-month effort from the Eastern North Atlantic (ENA) field campaign to advance the research and explore remote operation of the plug-and-play Portable Ice Nucleation Experiment (PINE) chamber to semi-autonomously measure marine boundary layer INP concentrations. In this campaign we deployed our PINE chamber at the U.S. Department of Energy Atmospheric Radiation Measurement (DOE ARM) ENA site on Graciosa Island, Azores (39° 5′ 29.76″ N, 28° 1′ 32.52″ W). The PINE chamber has been continuously operated since October 2020 with supervision and periodic remote maintenance by scientists in West Texas. The INP measurements were conducted at mixed-phase cloud conditions at temperatures between -14°C and -33°C. These measurements, along with other aerosol particle and meteorological measurements made by a suite of instruments collocated at the DOE ARM site, give unique insights on the response of INP concentrations to local and mesoscale dynamics and thermodynamic processes. This study provides the first remote and continuous INP measurements over two meteorological seasons made in the ENA region within the marine boundary layer, giving insights into an area with prominent marine influences on aerosol populations. Graciosa Island is a small island (only 61 km<sup>2</sup>) surrounded by oligotrophic oceans, and these measurements were made during the most biologically productive time of year for phytoplankton in the surrounding ocean waters. The long-term and continuous nature of these measurements allows a unique comparison of marine biological productivity, using satellite-derived chlorophyll a as a proxy for biomass, and INP concentrations. The median INP concentrations at -25 °C and -30 °C were around 4 INP L<sup>-1</sup> and 27 INP L<sup>-1 </sup>respectively. Our preliminary data suggest that INP concentrations measured by the PINE chamber at the ENA site are comparable to other studies at locations with primarily marine INPs. More details will be offered in our presentation.</p>

scholarly journals Summertime Post-Cold-Frontal Marine Stratocumulus Transition Processes over the Eastern North Atlantic

2020 ◽  
Vol 77 (6) ◽  
pp. 2011-2037 ◽  
Author(s):  
Melissa kazemirad ◽  
Mark A. Miller
Keyword(s):  
North Atlantic ◽  
Marine Boundary Layer ◽  
Potential Temperature ◽  
Wrf Model ◽  
Cloud Base ◽  
Equivalent Potential Temperature ◽  
Cumulus Clouds ◽  
Equivalent Potential ◽  
Atmospheric Radiation Measurement ◽  
Eastern North Atlantic

Abstract Marine boundary layer (MBL) cloud morphology associated with two summertime cold fronts over the eastern North Atlantic (ENA) is investigated using high-resolution simulations from the Weather Research and Forecasting (WRF) Model and observations from the Atmospheric Radiation Measurement (ARM) ENA Climate Research Facility. Lagrangian trajectories are used to study the evolution of post-cold-frontal MBL clouds from solid stratocumulus to broken cumulus. Clouds within specified domains in the vicinity of transitions are classified according to their degree of decoupling, and cloud-base and cloud-top breakup processes are evaluated. The Lagrangian derivative of the surface latent heat flux is found to be strongly correlated with that of the cloud fraction at cloud base in the simulations. Cloud-top entrainment instability (CTEI) is shown to operate only in the decoupled MBL. A new indicator of inversion strength at cloud top that employs the vertical gradients of equivalent potential temperature and saturation equivalent potential temperature, which can be computed directly from soundings, is proposed as an alternative to CTEI. Overall, results suggest that the deepening–warming hypothesis suggested by Bretherton and Wyant explains many of the characteristics of the summertime postfrontal MBL evolution of cloud structure over the ENA, thereby widening the phase space over which the hypothesis may be applied. A subset of the deepening–warming hypothesis involving warming initially dominating over moistening is proposed. It is postulated that changes in climate change–induced modifications in cold-frontal structure over the ENA may be accompanied by coincident changes in the location and timing of MBL cloud transitions in the post-cold-frontal environment.

Temperature, Salinity and Plankton in the Eastern North Atlantic and Coastal Waters of Britain, 1957.: I. The Characterisation and Distribution of Surface Waters

1963 ◽  
Vol 20 (3) ◽  
pp. 789-826 ◽  
Author(s):  
B. McK. Bary
Keyword(s):  
North Sea ◽  
North Atlantic ◽  
Coastal Waters ◽  
Water Bodies ◽  
English Channel ◽  
Oceanic Water ◽  
Climatic Fluctuations ◽  
The North ◽  
The North Sea ◽  
Eastern North Atlantic

Monthly temperature-salinity diagrams for 1957 have demonstrated that three surface oceanic "water bodies" were consistently present in the eastern North Atlantic; two are regarded as modified North Atlantic Central water which give rise to the third by mixing. As well in the oceanic areas, large and small, high or low salinity patches of water were common. Effects of seasonal climatic fluctuations differed in the several oceanic water bodies. In coastal waters, differences in properties and in seasonal and annual cycles of the properties distinguish the waters from the North Sea, English Channel and the western entrance to the Channel.The geographic distributions of the oceanic waters are consistent with "northern" and "southern" water bodies mixing to form a "transitional" water. Within this distribution there are short-term changes in boundaries and long-term (seasonal) changes in size of the water bodies.Water in the western approaches to the English Channel appeared to be influenced chiefly by the mixed, oceanic transitional water; oceanic influences in the North Sea appear to have been from northern and transitional waters.

A longitudinal study of humpback whales in Irish waters

2015 ◽  
Vol 96 (4) ◽  
pp. 877-883 ◽  
Author(s):  
Conor Ryan ◽  
Pádraig Whooley ◽  
Simon D. Berrow ◽  
Colin Barnes ◽  
Nick Massett ◽  
...  
Keyword(s):  
Longitudinal Study ◽  
North Atlantic ◽  
Spatial Scales ◽  
Humpback Whales ◽  
Migratory Species ◽  
The Public ◽  
Photo Identification ◽  
The North ◽  
Breeding Grounds ◽  
Eastern North Atlantic

Knowledge on the ecology of humpback whales in the eastern North Atlantic is lacking by comparison with most other ocean basins. Humpback whales were historically over-exploited in the region and are still found in low relative abundances. This, coupled with their large range makes them difficult to study. With the aim of informing more effective conservation measures in Ireland, the Irish Whale and Dolphin Group began recording sightings and images suitable for photo-identification of humpback whales from Irish waters in 1999. Validated records submitted by members of the public and data from dedicated surveys were analysed to form a longitudinal study of individually recognizable humpback whales. The distribution, relative abundance and seasonality of humpback whale sighting records are presented, revealing discrete important areas for humpback whales in Irish coastal waters. An annual easterly movement of humpback whales along the southern coast of Ireland is documented, mirroring that of their preferred prey: herring and sprat. Photo-identification images were compared with others collected throughout the North Atlantic (N = 8016), resulting in matches of two individuals between Ireland and Iceland, Norway and the Netherlands but no matches to known breeding grounds (Cape Verde and West Indies). This study demonstrates that combining public records with dedicated survey data is an effective approach to studying low-density, threatened migratory species over temporal and spatial scales that are relevant to conservation and management.

scholarly journals Crassicauda boopis in a fin whale (Balaenoptera physalus) ship-struck in the eastern North Atlantic Ocean

2017 ◽  
Vol 3 ◽  
Author(s):  
LAETITIA LEMPEREUR ◽  
MORGAN DELOBELLE ◽  
MARJAN DOOM ◽  
JAN HAELTERS ◽  
ETIENNE LEVY ◽  
...  
Keyword(s):  
North Atlantic ◽  
18S Rrna ◽  
North Atlantic Ocean ◽  
18S Rrna Gene ◽  
The Body ◽  
Rrna Gene ◽  
Balaenoptera Physalus ◽  
Fin Whale ◽  
Eastern North Atlantic ◽  
The Right

SUMMARY On 9 November 2015, a juvenile male fin whale of 11·60 m length was observed on the bulb of a merchant vessel in the Channel Terneuzen – Ghent (The Netherlands – Belgium). A severe parasitosis was present in the right heart ventricle and caudal caval vein. Parasites were identified as Crassicauda boopis based on macroscopic and microscopic observations. The sequence of the 18S rRNA gene obtained from the parasite samples was 100% similar to the sequence of the 18S rRNA gene from Crassicauda magna available on GenBank. While adults of C. boopis and C. magna are morphologically distinct and found at different locations in the body, the molecular analysis of the 18S rRNA gene seems insufficient for reliable species identification. Although numerous C. boopis were found, the cause of death was identified as due to the collision with the ship, as suggested by the presence of a large haematoma, and the absence of evidence of renal failure. The young age of this whale and the absence of severe chronic reaction may suggest that the infestation was not yet at an advanced chronic stage.

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