Investigation of atmospheric boundary layer thermodynamics at the Sakhalin Island by using a microwave temperature profiler,

[1] The MTP-5, a microwave temperature profiler, has been widely used since 1991 for investigation of the atmospheric boundary layer (ABL). The MTP-5 is an angular scanning single-channel instrument with a central frequency of about 60 GHz, designed to provide continuous, unattended observations. It can measure the thermal emission of the atmosphere with high sensitivity (0.03 K at 1 s integration time) from different zenith angles. On the basis of this measurement, it is possible to retrieve temperature profiles at the altitude range up to 600 m, to calculate wind speed and wind direction at the lowest 250 m, and to get information about some parameters of atmospheric turbulence. This report presents some applications of the MTP-5 instrument data collected in 1998-2001 within a number of international field projects: the dynamics of ABL temperature inversion in a mountain valley (Mesoscale Alpine Program (MAP)), as well as along an island coast (north part of Sakhalin Island, Russia-Japan Project); continuous measurements of the ABL temperature profile provided from a special scientific train that crossed the territory of Russia (the Transcontinental Observations of the Chemistry of the Atmosphere Project (TROICA)); and simultaneous measurements of the ABL temperature profile provided over the central and northern part of Moscow in a continuous mode (the Global Urban Research Meteorology and Environment Project (GURME)). In 1999, two MTP-5 instruments were installed on a platform that was rotating in the azimuth direction at the 310 m Obninsk Meteorological Research Tower (Meteo Tower) to validate the method and microwave equipment for measurement of wind speed and wind direction and investigation of atmospheric turbulence. Spectral analyses of the integrated signal provided an opportunity to estimate the inertial subrange low-frequency limit and its height dependence for thermal turbulence at the lowest 200 m layer. Wavelet analysis of the signal made it possible to determine the convective thermic and other coherent structures; also to estimate energy and to provide visualization of the transformation processes of those structures during changing ABL stability. For a wide spectrum of ABL models the integrated character of radiometric data is more representative than in situ data. The measurement cycle for main wind is about 45 min, with an accuracy of about 1-2 m/s for wind speed and 10-20°for wind direction. Measurements at different levels of the Meteo Tower of vertical wind speed were in good agreement with in situ data. The possibility of manufacturing the microwave instrument for simultaneous measurements of the temperature profile and wind parameters in the ABL will be also discussed in this report

Microwave balloon measurements of the stratospheric temperature

310-311The results of balloon flight with nadir microwave thermal sounding launched on 25 July 1990 from Rylsk base are presented. Radiometer without image rejection operating at the slopes of 9+ and 11- oxygen resonance lines and having 6 channels with bands of 3-150 MHz and sensitivities of 0.6-0.09 K has been used

RESULTS OF LIQUID WATERPATH AND WATER CONTENT AND MIXING RATIO BY MEANS OF MICROWAVE RADIOMETER “MICRORADKOM” MADE IN CAO

The application of "Mikroradkom" microwave radiometer developed in CAO to the study of the fine thermodynamic processes occurring in the cloud in different seasons is discussed. The equations offered by the authors of the work make it possible to study in details all the effect of the phase state and microstructure of the cloud transformation during ongoing processes in it within a wide range of time scales. The application of modern highly sensitive radiometric equipment and in-depth analysis of the information offered on the basis of the relations mentioned allow us to make deeper insight into the geophysical factors and processes that affect the formation of self-radiation of the atmosphere

On the potential of the ICOS atmospheric CO₂ measurement network for estimating the biogenic CO₂ budget of Europe

International audienceWe present a performance assessment of the Eu-ropean Integrated Carbon Observing System (ICOS) atmospheric network for constraining European biogenic CO 2 fluxes (hereafter net ecosystem exchange, NEE). The performance of the network is assessed in terms of uncertainty in the fluxes, using a state-of-the-art mesoscale variational atmospheric inversion system assimilating hourly averages of atmospheric data to solve for NEE at 6 h and 0.5 • resolution. The performance of the ICOS atmospheric network is also assessed in terms of uncertainty reduction compared to typical uncertainties in the flux estimates from ecosystem models, which are used as prior information by the inversion. The uncertainty in inverted fluxes is computed for two typical periods representative of northern summer and winter conditions in July and in December 2007, respectively. These computations are based on a observing system simulation experiment (OSSE) framework. We analyzed the uncertainty in a 2-week-mean NEE as a function of the spatial scale with a focus on the model native grid scale (0.5 •), the country scale and the European scale (including western Rus-sia and Turkey). Several network configurations, going from 23 to 66 sites, and different configurations of the prior uncertainties and atmospheric model transport errors are tested in order to assess and compare the improvements that can be expected in the future from the extension of the network, from improved prior information or transport models. Assimilating data from 23 sites (a network comparable to present-day capability) with errors estimated from the present prior information and transport models, the uncertainty reduction on a 2-week-mean NEE should range between 20 and 50 % for 0.5 • resolution grid cells in the best sampled area encompassing eastern France and western Germany. At the Eu-ropean scale, the prior uncertainty in a 2-week-mean NEE is reduced by 50 % (66 %), down to ∼ 43 Tg C month −1 (26 Tg C month −1) in July (December). Using a larger network of 66 stations, the prior uncertainty of NEE is reduced by the inversion by 64 % (down to ∼ 33 Tg C month −1) in July and by 79 % (down to ∼ 15 Tg C month −1) in December. When the results are integrated over the well-observed western European domain, the uncertainty reduction shows no seasonal variability. The effect of decreasing the correlation length of the prior uncertainty, or of reducing the transport model errors compared to their present configuration (when conducting real-data inversion cases) can be larger than that of the extension of the measurement network in areas where the 23 station observation network is the densest. We show that with a configuration of the ICOS atmospheric network containing 66 sites that can be expected on the long-term, the uncertainties in a 2-week-mean NEE will be reduced by up to 50-80 % for countries like Finland, Germany, France and Spain, which could significantly improvement (and at least a high complementarity to) our knowledge of NEE derived from biomass and soil carbon inventories at multi-annual scales

Turbulence Structure and Exchange Processes in an Alpine Valley: The Riviera Project.

During a special observing period (SOP) of the Mesoscale Alpine Programme (MAP), boundary layer processes in highly complex topography were investigated in the Riviera Valley in southern Switzerland. The main focus was on the turbulence structure and turbulent exchange processes near the valley surfaces and free troposphere. Due to the anticipated spatial inhomogeneity, a number of different turbulence probes were deployed on a cross section through the valley. Together with a suite of more conventional instrumentation, to observe mean meteorological structure in the valley, this effort yielded a highly valuable dataset. The latter is presently being exploited to yield insight into the turbulence structure in very complex terrain, and its relation to flow regimes and associated mean flow characteristics. Specific questions, such as a detailed investigation of turbulent exchange processes over complex topography and the validity of surface exchange parameterizations in numerical models for such surfaces, the closure of the surface energy balance, or the definition and meaning of the “boundary layer height,” are investigated using the MAP-Riviera dataset. In the present paper, we provide details on sites and their characteristics, on measurements and observational strategies, and on efforts to guarantee comparability between different instrumentation at different sites, and we include an overview of the available instrumentation. On the basis of preliminary data and first results, the main research goals of the project are outlined. Copyright 2004 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act or that satisfies the conditions specified in Section 108 of the U.S. Copyright Act (17 USC §108, as revised by P.L. 94-553) does not require the AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a web site or in a searchable database, or other uses of this material, except as exempted by the above statement, requires written permission or a license from the AMS. Additional details are provided in the AMS Copyright Policy, available on the AMS Web site located at (http://www.ametsoc.org/) or from the AMS at 617-227-2425 or [email protected], Faculty ofEarth and Ocean Sciences, Department ofReviewedFacult