The Identification and Verification of Hazardous Convective Cells over Oceans Using Visible and Infrared Satellite Observations

Donovan, Michael; Williams, Earle; Kessinger, Cathy; Blackburn, Gary; Herzegh, Paul H.; Bankert, Richard L.; Miller, S. D.; Mosher, Frederick R.

doi:10.1175/2007jamc1471.1

Cited by 25 publications

(16 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They found that the difference between the InfraRed (IR) window channel and the water vapor channel can be used to detect Cbs. The approach is used currently for the operational detection of Cbs, e.g., [2,3]. More recently, it has been shown that mature Cbs can be detected by satellites with relatively high POD and low FAR, if the brightness temperature difference method according to [1] is applied to two water vapor channels (7.3 µm and 6.2 µm) in combination with Numerical Weather Prediction (NWP) filtering [4].…”

Section: Introductionmentioning

confidence: 99%

A Novel Approach for the Detection of Developing Thunderstorm Cells

et al. 2019

View full text Add to dashboard Cite

This study presents a novel approach for the early detection of developing thunderstorms. To date, methods for the detection of developing thunderstorms have usually relied on accurate Atmospheric Motion Vectors (AMVs) for the estimation of the cooling rates of convective clouds, which correspond to the updraft strengths of the cloud objects. In this study, we present a method for the estimation of the updraft strength that does not rely on AMVs. The updraft strength is derived directly from the satellite observations in the SEVIRI water vapor channels. For this purpose, the absolute value of the vector product of spatio-temporal gradients of the SEVIRI water vapor channels is calculated for each satellite pixel, referred to as Normalized Updraft Strength (NUS). The main idea of the concept is that vertical updraft leads to NUS values significantly above zero, whereas horizontal cloud movement leads to NUS values close to zero. Thus, NUS is a measure of the strength of the vertical updraft and can be applied to distinguish between advection and convection. The performance of the method has been investigated for two summer periods in 2016 and 2017 by validation with lightning data. Values of the Critical Success Index (CSI) of about 66% for 2016 and 60% for 2017 demonstrate the good performance of the method. The Probability of Detection (POD) values for the base case are 81.8% for 2016 and 89.2% for 2017, respectively. The corresponding False Alarm Ratio (FAR) values are 22.6% (2016) and 36.4% (2017), respectively. In summary, the method has the potential to reduce forecast lead time significantly and can be quite useful in regions without a well-maintained radar network.

show abstract

Section: Introductionmentioning

confidence: 99%

A Novel Approach for the Detection of Developing Thunderstorm Cells

et al. 2019

View full text Add to dashboard Cite

show abstract

“…As a result, cloud top height is an option used as a straightforward method to provide information about the risk for cumulonimbus cloud occurrence as operated by, e.g., NCAR ( [2] and references therein). The cloud top height can be derived from the brightness temperature (BT) in the atmospheric window channel (InfraRed 10.6), which corresponds in good approximation with the temperature of the cloud top for Cbs.…”

Section: Introductionmentioning

confidence: 99%

“…Another simple, but widely used method is that applied in the Global Convective Diagnostics approach [2,4]. The method uses the brightness temperature difference between the 6.7 µm the 11.6 µm infrared satellite channel, the former is also referred to as water vapour channel, because of the strong water vapour absorption bands.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The Role of NWP Filter for the Satellite Based Detection of Cumulonimbus Clouds

Müller¹,

Haussler²,

Jerg³

2018

Remote Sensing

View full text Add to dashboard Cite

This study is motivated by the great importance of Cbs for aviation safety. The study investigates the role of Numerical Weather Prediction (NWP) filtering for the remote sensing of Cumulonimbus Clouds (Cbs) by implementation of about 30 different experiments, covering Central Europe. These experiments compile different stability filter settings as well as the use of different channels for the InfraRed (IR) brightness temperatures (BT). As stability filters, parameters from Numerical Weather Prediction (NWP) are used. The application of the stability filters restricts the detection of Cbs to regions with a labile atmosphere. Various NWP filter settings are investigated in the experiments. The brightness temperature information results from the infrared (IR) Spinning Enhanced Visible and InfraRed Image (SEVIRI) instrument on-board of the Meteosat Second Generation satellite and enables the detection of very cold and high clouds close to the tropopause. Various satellite channels and BT thresholds are applied in the different experiments. The satellite only approaches (no NWP filtering) result in the detection of Cbs with a relative high probability of detection, but unfortunately combined with a large False Alarm Rate (FAR), leading to a Critical Success Index (CSI) below 60% for the investigated summer period in 2016. The false alarms result from other types of very cold and high clouds. It is shown that the false alarms can be significantly decreased by application of an appropriate NWP stability filter, leading to the increase of CSI to about 70% for 2016. CSI is increased from about 70 to about 75% by application of NWP filtering for the other investigated summer period in 2017. A brief review and reflection of the literature clarify that the function of the NWP filter can not be replaced by MSG IR spectroscopy. Thus, NWP filtering is strongly recommended to increase the quality of satellite based Cb detection. Further, it has been shown that the well established convective available potential energy (CAPE) and the convection index (KO) work well as a stability filter.

show abstract

“…The IR window technique uses the 11-^m thermal IR temperature to estimate the temperature at cloud top, combined with an atmospheric sounding to convert the temperature value to a corresponding pressure and height. The AWRP oceanic weather PDT's current en route cloudtop height product (CTOP) is based on the IR window technique (Donovan et al 2007). Figure 1 shows an example of this GOES imagerbased cloud-top pressure product.…”

mentioning

confidence: 99%