The COPE field campaign will be held in the south west peninsula of England during June, July and August, 2013. The map below shows the location of key facilities and instrumentation: the operations and forecasting centre will be at the Met Office in Exeter; the Facility for Airborne Atmospheric Measurement (FAAM) BAe 146 and the University of Wyoming King Air (N2UW) will be based at Exeter Airport; and the Facility for Ground based Atmospheric Measurement (FGAM) instruments will be located at two sites near Davidstow.
The purpose of the radar measurements is to determine (in conjunction with the aircraft measurements):
(a) particle types from dual-polarisation capabilities of the radars
(b) the location in the cloud of the first echoes
(c) the development of the reflectivity echo and the maximum intensity of the precipitation, and
(d) the cloud dynamics using dual-Doppler information.
There are three operational Met Office network radars covering the southwest peninsula: Predannack, Cobbacombe Cross and Dean Hill (shown in blue with 100km range rings). The scan schedule has a repeat cycle of 5 minutes with typically 8 elevations between 0 and 8 degrees, providing measurements of reflectivity and Doppler velocity out to 255km, and refractivity out to about 30km. The research radar at Wardon Hill will provide additional coverage and along with Predannack will have dual-polarisation capability.
|Chilbolton Radar||FGAM Radar||Micro Rain Radar|
The S-band Chilbolton Advanced Meteorological Radar (CAMRa) will also provide measurements of precipitation intensity and type, and associated velocity distributions, out to a maximum range of 200 km (black range rings at 100 and 200km).
The newly aqcuired FGAM X-band radar will be deployed on the old airfield at Davidstow and will be able to optimize its scanning pattern and data retrieval according to cloud development. The CAMRa and FGAM radars will be operated continuously during Intensive Observation Periods (IOPs).
A Micro Rain Radar also deployed near Davidstow will provide vertical profiles of reflectivity, rain rate, drop size distributions, velocity of hydrometeors and other parameters up to several kilometres height.
Profilers and Surface Stations
Vertical profilers and surface station networks will be used to provide measurements of:
(a) the temporal and spatial distribution of water vapour and temperature in the boundary layer and troposphere
(b) the vertical profile of wind and stability
(b) the structure and persistence of convergence lines
|FGAM Wind Profiler||FGAM Doppler Lidar|
The dynamics of the boundary layer and free troposphere will also be intensively sampled within the range of the radars using the FGAM wind profiler, Doppler lidar and radiometer, deployed near Davidstow, all of which operate continuously. The Met Office operates two further wind profilers at Camborne and Dunkeswell. Routine radiosonde profiles will be provided by the Met Office operational station at Camborne at 0000 and 1200 UTC. More frequent ascents will be requested when required from Camborne and occasionally Larkhill. The Cardington Facility mobile system will be positioned in strategic locations near Davidstow depending on the forecast and will provide 2-hourly ascents during periods of interest.
The Met Office surface station network produces observations at one minute intervals, which will be available during COPE. There are also a large number of amateur weather stations archived through the Weather Observatiosn Website (WOW) and other internet hosts such as Weather Underground.
Ground-based aerosol measurements will be made by the Manchester aerosol laboratory set up in a temporary portacabin located near Davidstow.
The FAAM and N2UW aircraft will be used to make aerosol, cloud physics and cloud dynamics measurements. The specific purpose of the aircraft is to link the comprehensive ground-based aerosol measurements to the aerosols that are ingested into the cloud.
The key aerosol properties to be determined are:
(a) the physical, chemical, hygroscopic, and ice nucleating properties of the aerosol particles
(b) the concentration of biological aerosols or soil dust coated with biological material and their role in ice nucleation
(c) the concentration and coatings of mineral dust aerosols from long-range transport and their role in ice nucleation
The cloud physics measurements will be used to determine:
(a) how supercooled raindrops are produced
(b) the temperature and location in the cloud where ice particles first form and the concentration of those particles
(c) the spatial distribution and the evolution of the ice particle size distribution
(d) where precipitation particles first form and how they develop
The N2UW has two additional observational systems onboad: a cloud radar and a cloud lidar for studying cloud structure and composition. The radar provides high-resolution measurements of reflectivity, velocity and polarization fields. Coupled with the in situ observations of hydrometeors and air motions from the same aircraft these data yield unique information for analysis of cloud and precipitation processes. The lidar provides high spatial resolution cloud base measurements, as well as cloud and aerosol extinction coefficient and depolarization profiles.
The project will have access in real time to radar data, satellite imagery, radiosonde data and surface data.
A forecast and operations meeting will be held every day at 07:00 local time (or earlier if the weather dictates) in the Met Office with a conference call to Davidstow personnel, to discuss:
(a) the forecast for the current day, the upcoming flight and radar operations
(b) if the next day is to be an IOP
(c) the outlook for the next 2-5 days to identify potential IOPs
(d) instrument status
UK post-processing (UKPP) will provide hourly updated nowcasts based on the STochastic Ensemble Prediction System (STEPs) and the UK 1.5 km model. The UKV 1.5 km model will provide forecasts for 36 hours and is updated every 6 hours. In addition there is likely to be a small 1.5 km ensemble to provide estimates of uncertainty. Longer forecast guidance will come from the European regional 12 km model (2 days) and the global 25 km model (6 days), with coarser-resolution ensembles out to 15 days. An hourly-updated demonstration 1.5 km model may also be available for short-range forecasts.
The IOP will be followed by a de-brief meeting to discuss the summary of the day's activities and plans for the next day.