Construction of Consistent Temperature Records in the Lower Stratosphere Using Global Positioning System Radio Occultation Data and Microwave Sounding Measurements

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.

Download Full-text

Semidiurnal tidal signature in sporadic E occurrence rates derived from GPS radio occultation measurements at higher midlatitudes

Annales Geophysicae ◽

10.5194/angeo-27-2555-2009 ◽

2009 ◽

Vol 27 (6) ◽

pp. 2555-2563 ◽

Cited By ~ 57

Author(s):

C. Arras ◽

C. Jacobi ◽

J. Wickert

Keyword(s):

Global Positioning System ◽

Zonal Wind ◽

Radio Occultation ◽

Positioning System ◽

Semidiurnal Tide ◽

Meteor Radar ◽

Global Positioning ◽

Sporadic E Layer ◽

Sporadic E ◽

Wind Shears

Abstract. GPS (Global Positioning System) Radio occultation (RO) measurements from CHAMP, GRACE and FORMOSAT-3/COSMIC satellites at Northern Hemisphere midlatitides (50°–55° N) are analysed to obtain the diurnal variation of sporadic E layer occurrence frequency in 2006 and 2007. Interconnections with zonal wind shears measured by meteor radar at Collm (51.3° N, 13° E), Germany, are investigated. According to theory, maximum Es occurrence is expected when the zonal wind shear, which is mainly produced by the semidiurnal tide in midlatitudes, is negative. This is confirmed by the present measurements and analysis.

Download Full-text

A global analysis of wave potential energy in the lower stratosphere derived from 5 years of GPS radio occultation data with CHAMP

Geophysical Research Letters ◽

10.1029/2006gl027696 ◽

2006 ◽

Vol 33 (24) ◽

Cited By ~ 59

Author(s):

A. de la Torre ◽

T. Schmidt ◽

J. Wickert

Keyword(s):

Potential Energy ◽

Radio Occultation ◽

Lower Stratosphere ◽

Global Analysis ◽

Gps Radio Occultation ◽

Wave Potential ◽

Occultation Data ◽

Radio Occultation Data

Download Full-text

Seasonal and Annual Changes of the Regional Tropical Belt in GPS-RO Measurements and Reanalysis Datasets

Journal of Climate ◽

10.1175/jcli-d-19-0671.1 ◽

2020 ◽

Vol 33 (10) ◽

pp. 4083-4094

Author(s):

Lan Luan ◽

Paul W. Staten ◽

Chi O. Ao ◽

Qiang Fu

Keyword(s):

Northern Hemisphere ◽

Global Positioning System ◽

Radio Occultation ◽

Hadley Circulation ◽

Positioning System ◽

Observational Dataset ◽

Tropical Tropopause ◽

Subtropical Jet ◽

Global Positioning ◽

Belt Width

AbstractThe width of the tropical belt has been analyzed with a variety of metrics, often based on zonal-mean data from reanalyses. However, constraining the global and regional tropical width requires both a global spatial-resolving observational dataset and an appropriate metric to take advantage of such data. The tropical tropopause break is arguably such a metric. This study aims to evaluate the performance of different reanalyses and metrics with a focus on depicting regional tropical belt width. We choose four distinct tropopause-break metrics derived from global positioning system radio occultation (GPS-RO) satellite data and four modern reanalyses (ERA-Interim, MERRA-2, JRA-55, and CFSR). We show that reanalyses generally reproduce the regional tropical tropopause break to within 10° of that in GPS-RO data—but that the tropical width is somewhat sensitive (within 4°) to how data are averaged zonally, moderately sensitive (within 10°) to the dataset resolution, and more sensitive (20° over the Northern Hemisphere Atlantic Ocean during June–August) to the choice of metric. Reanalyses capture the poleward displacement of the tropical tropopause break over land and equatorward displacement over ocean during summertime, and the reverse during the wintertime. Reanalysis-based tropopause breaks are also generally well correlated with those from GPS-RO, although CFSR reproduces 14-yr trends much more closely than others (including ERA-Interim). However, it is hard to say which dataset is the best match of GPS-RO. We further find that the tropical tropopause break is representative of the subtropical jet latitude and the Northern Hemisphere edge of the Hadley circulation in terms of year-to-year variations.

Download Full-text