HOAPS and ERA-Interim precipitation over sea: Validation against  shipboard in-situ measurements

Bumke, Karl; König-Langlo, Gert; Kinzel, Julian; Schröder, Marc

doi:10.5194/amt-2016-22

Cited by 3 publications

(4 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Information for the meteorological data (2005)(2006)(2007)(2008) and observatory of R/V Polarstern can be found in König-Langlo et al (2006). Precipitation measurements of the 1995-1997 period, measurements on R/V Alkor and on the GEOMAR building in Kiel are archived in the Pangaea data library (Bumke et al, 2016). ERA-Interim data are accessible via the ECMWF data server.…”

Section: Data Availabilitymentioning

confidence: 99%

HOAPS and ERA-Interim precipitation over the sea: validation against shipboard in situ measurements

et al. 2016

Self Cite

View full text Add to dashboard Cite

Abstract. The satellite-derived HOAPS (Hamburg OceanAtmosphere Parameters and Fluxes from Satellite Data) and ECMWF (European Centre for Medium-Range Weather Forecasts) ERA-Interim reanalysis data sets have been validated against in situ precipitation measurements from ship rain gauges and optical disdrometers over the open ocean by applying a statistical analysis for binary estimates. For this purpose collocated pairs of data were merged within a certain temporal and spatial threshold into single events, according to the satellites' overpass, the observation and the ERAInterim times. HOAPS detects the frequency of precipitation well, while ERA-Interim strongly overestimates it, especially in the tropics and subtropics. Although precipitation rates are difficult to compare because along-track point measurements are collocated with areal estimates and the number of available data are limited, we find that HOAPS underestimates precipitation rates, while ERA-Interim's Atlantic-wide average precipitation rate is close to measurements. However, when regionally averaged over latitudinal belts, deviations between the observed mean precipitation rates and ERAInterim exist. The most obvious ERA-Interim feature is an overestimation of precipitation in the area of the intertropical convergence zone and the southern subtropics over the Atlantic Ocean. For a limited number of snow measurements by optical disdrometers, it can be concluded that both HOAPS and ERA-Interim are suitable for detecting the occurrence of solid precipitation.

show abstract

Section: Data Availabilitymentioning

confidence: 99%

HOAPS and ERA-Interim precipitation over the sea: validation against shipboard in situ measurements

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…In contrast to p2a methods for stationary networks of ground-based gauges and radars over land (e.g., [3,28]), shipboard disdrometers produce along-track measurements, which complicates their p2a adjustment. In that respect, the developed statistical adjustments could extend event-based statistics with along-track averaging such as in [14] to reduce the influence of the p2a problem in validating satellite and reanalysis data.…”

Section: Proposed Statistical Track-to-area Adjustmentmentioning

confidence: 99%

“…Simulations of p2a collocations exist over the Baltic Sea based on radar reflectivity [13]. However, the p2a problem has never been addressed explicitly in a simulation with radar data beyond the combination of precipitation events [14].…”

Section: Introductionmentioning

confidence: 99%

Simulation of Ship-Track versus Satellite-Sensor Differences in Oceanic Precipitation Using an Island-Based Radar

et al. 2017

View full text Add to dashboard Cite

Abstract:The point-to-area problem strongly complicates the validation of satellite-based precipitation estimates, using surface-based point measurements. We simulate the limited spatial representation of light-to-moderate oceanic precipitation rates along ship tracks with respect to areal passive microwave satellite estimates using data from a subtropical island-based radar. The radar data serves to estimate the discrepancy between point-like and areal precipitation measurements. From the spatial discrepancy, two statistical adjustments are derived so that along-track precipitation ship data better represent areal precipitation estimates from satellite sensors. The first statistical adjustment uses the average duration of a precipitation event as seen along a ship track, and the second adjustment uses the median-normalized along-track precipitation rate. Both statistical adjustments combined reduce the root mean squared error by 0.24 mm h −1 (55%) compared to the unadjusted average track of 60 radar pixels in length corresponding to a typical ship speed of 24-34 km h −1 depending on track orientation. Beyond along-track averaging, the statistical adjustments represent an important step towards a more accurate validation of precipitation derived from passive microwave satellite sensors using point-like along-track surface precipitation reference data.

show abstract

“…The backbone of the OceanRAIN project is the ODM470 optical disdrometer 30 , 59 , 61 , 68 , 69 . An infrared light emitting diode at 880 nm homogeneously illuminates the measuring volume of 120 mm length and 22 mm diameter.…”

Section: Methodsmentioning

confidence: 99%

OceanRAIN, a new in-situ shipboard global ocean surface-reference dataset of all water cycle components

et al. 2018

View full text Add to dashboard Cite

OceanRAIN—the Ocean Rainfall And Ice-phase precipitation measurement Network—provides in-situ along-track shipboard data of precipitation, evaporation and the resulting freshwater flux at 1-min resolution over the global oceans from June 2010 to April 2017. More than 6.83 million minutes with 75 parameters from 8 ships cover all routinely measured atmospheric and oceanographic state variables along with those required to derive the turbulent heat fluxes. The precipitation parameter is based on measurements of the optical disdrometer ODM470 specifically designed for all-weather shipboard operations. The rain, snow and mixed-phase precipitation occurrence, intensity and accumulation are derived from particle size distributions. Additionally, microphysical parameters and radar-related parameters are provided. Addressing the need for high-quality in-situ precipitation data over the global oceans, OceanRAIN-1.0 is the first comprehensive along-track in-situ water cycle surface reference dataset for satellite product validation and retrieval calibration of the GPM (Global Precipitation Measurement) era, to improve the representation of precipitation and air-sea interactions in re-analyses and models, and to improve understanding of water cycle processes over the global oceans.

show abstract

HOAPS and ERA-Interim precipitation over sea: Validation against shipboard in-situ measurements

Cited by 3 publications

References 29 publications

HOAPS and ERA-Interim precipitation over the sea: validation against shipboard in situ measurements

HOAPS and ERA-Interim precipitation over the sea: validation against shipboard in situ measurements

Simulation of Ship-Track versus Satellite-Sensor Differences in Oceanic Precipitation Using an Island-Based Radar

OceanRAIN, a new in-situ shipboard global ocean surface-reference dataset of all water cycle components

Contact Info

Product

Resources

About