Info-seminar on last call EC FP7 Marie Curie Fellowships 2013  - 15th May 2013 at ICTP, LB - Euler Lecture Hall

ICTP and SISSA have organized along with APRE Rome an Info-seminar on the last call of EC FP7 Marie Curie Fellowships 2013 to be held at ICTP, LB - Euler Lecture Hall,please see attached programme for details.

Everybody at ICTP is invited to sign up within 9 May 2013, email to: hennings@ictp.it and  segsci@sissa.it

CONSYDER will be "Example of good pratice" :-)

Background

Bending Angle and Temperature Climatologies from Global Positioning System Radio Occultations, Biondi, R., and Neubert, T., Dataset Papers in Geosciences, Volume 2013 (2013), Article ID 795749, 5 pages, http://dx.doi.org/10.7167/2013/795749

http://www.hindawi.com/dpis/geosciences/2013/795749/

The Global Positioning System (GPS) Radio Occultation (OR) technique provides estimates of atmospheric density, temperature, and water vapour content with high vertical resolution, global coverage, and high accuracy. We have used data acquired using this technique in the period 1995–2009 to create a reference climatology of radio occultation bending angle and atmospheric temperature which are used for meteorological studies. The bending angle is interesting because it is a direct measurement and independent of models. It is given with one-degree spatial resolution and 50-meter vertical sampling. In addition, we give the temperature climatology with one-degree spatial resolution and 100-meter vertical sampling. This dataset can be used for several applications including weather forecast, physics of atmosphere, and climate changes. Since the GPS signal is not affected by clouds and the acquisitions are evenly distributed in the globe, the dataset is well suited for studying extreme events (such as convective systems and tropical cyclones) and remote areas.

Collaborations

CONSYDER will be supervised by Wegener Center (University of Graz - Austria).

The background was developed at DTU-Space (DK) in collaboration with DMI (DK)

Collaborations are already ongoing with:
- UCAR/COSMIC (USA)
- NCAR/ACP (USA)
- ISAC/CNR (IT)

Connected projects

Convective Radio Occultations Campaign (CROC)

CROC is a campaign run within the US Atmospheric Radiation Measurement (ARM) Climate Research Facility, here the details: http://www.arm.gov/campaigns/twp2012CROC

Background

Thermal structure of intense convective clouds derived from GPS radio occultations, Biondi, R., Randel, W., Ho, S.-P., Neubert, T. and Syndergaard, S., Atmos. Chem. Phys., 12, 5309–5318, 2012, doi:10.5194/acp-12-5309-2012

www.atmos-chem-phys.net/12/5309/2012/

Thermal structure associated with deep convective clouds is investigated using Global Positioning System (GPS) radio occultation measurements. GPS data are insensitive to the presence of clouds, and provide high vertical resolution and high accuracy measurements to identify associated temperature behavior. Deep convective systems are identified using International Satellite Cloud Climatology Project (ISCCP) satellite data, and cloud tops are accurately measured using Cloud-Aerosol Lidar with Orthogonal Polarization (CALIPSO) lidar observations; we focus on 53 cases of near-coincident GPS occultations with CALIPSO profiles over deep convection. Results show a sharp spike in GPS bending angle highly correlated to the top of the clouds, corresponding to anomalously cold temperatures within the clouds. Above the clouds the temperatures return to background conditions, and there is a strong inversion at cloud top. For cloud tops below 14 km, the temperature lapse rate within the cloud often approaches a moist adiabat, consistent with rapid undiluted ascent within the convective systems.

Background 

Radio occultation bending angle anomalies during tropical cyclones, Biondi, R., Neubert, T., Syndergaard, S. and Nielsen, J., Atmos. Meas. Tech. Discuss., 4, 1371–1395, 2011, doi:10.5194/amtd-4-1371-2011 

www.atmos-meas-tech-discuss.net/4/1371/2011/

The tropical deep convection affects the radiation balance of the atmosphere changing the water vapor mixing ratio and the temperature of the upper troposphere lower stratosphere. The aim of this work is to better understand these processes and to investigate if severe storms leave a significant signature in radio occultation profiles in the tropical tropopause layer. Using tropical cyclone best track database and data from different GPS radio occultation missions (COSMIC, GRACE, CHAMP, SACC and GPSMET), we selected 1194 profiles in a time window of 3 h and a space window of 300 km from the eye of the cyclone. We show that the bending angle anomaly of a GPS radio occultation signal is typically larger than the climatology in the upper troposphere and lower stratosphere and that a double tropopause during deep convection can easily be
detected using this technique. Comparisons with co-located radiosondes, climatology of tropopause altitudes and GOES analyses are also shown to support the hypothesis that the bending angle anomaly can be used as an indicator of convective towers. The results are discussed in connection to the GPS radio occultation receiver which will be part of the Atomic Clock Ensemble in Space (ACES) payload on the International Space Station.

Background

Measurements of the upper troposphere and lower stratosphere during tropical cyclones using the GPS radio occultation technique, Biondi, R., Neubert, T., Syndergaard, S. and Nielsen, J., Advance in Space Research, Vol. 47 (2), pp. 348-355, 2011. 

http://www.sciencedirect.com/science/article/pii/S0273117710003765

Water vapour transport to the upper troposphere and lower stratosphere by deep convective storms affects the radiation balance of the atmosphere and has been proposed as an important component of climate change. The aim of the work presented here is to understand if the GPS radio occultation technique is useful for characterization of this process. Our assessment addresses the question if severe storms leave a significant signature in radio occultation profiles in the upper troposphere/lower stratosphere. Radio occultation data from the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) were analyzed, focusing on two particular tropical cyclones with completely different characteristics, the hurricane Bertha, which formed in the Atlantic Basin during July 2008 and reached a maximum intensity of Category 3, and the typhoon Hondo, which formed in the south Indian Ocean during 2008 reaching a maximum intensity of Category 4. The result is positive, suggesting that the bending angle of a GPS radio occultation signal contains interesting information on the atmosphere around the tropopause, but not any information regarding the water vapour. The maximum percentage anomaly of bending angle between 14 and 18 km of altitude during tropical cyclones is typically larger than the annual mean by 5–15% and it can reach 20% for extreme cases. The results are discussed in connection to the GPS radio occultation receiver which will be part of the Atomic Clock Ensemble in Space (ACES) payload on the International Space Station.