{"title":"Implementation of All-sky Assimilation of Microwave Humidity Sounding Channels in Environment Canada’s Global Deterministic Weather Prediction System","authors":"M. Shahabadi, Mark Buehner","doi":"10.1175/mwr-d-23-0227.1","DOIUrl":null,"url":null,"abstract":"\nCloud-affected microwave humidity sounding radiances were excluded from assimilation in 4D-EnVar system of the Global Deterministic Prediction System (GDPS) at Environment and Climate Change Canada (ECCC). This was due to the inability of the current radiative transfer model to consider the scattering effect from frozen hydrometeors at these frequencies. In addition to upgrading the observation operator to RTTOV-SCATT, quality control, bias correction, and 4D-EnVar assimilation components are modified to perform all-sky assimilation of Microwave Humidity Sounder (MHS) channels 2-5 observations over ocean in the GDPS. The input profiles to RTTOV-SCATT are extended to include liquid cloud, ice cloud, and cloud fraction profiles for the simulation and assimilation of MHS observations over water. There is a maximum 35% increase in number of channel 2 assimilated MHS observations with smaller increases for channels 3-5 in the all-sky compared to the clear-sky experiment, mostly because of newly assimilated cloud-affected observations. The stddev of difference between the observed GPSRO refractivity observations and the corresponding simulated values using the background state was reduced in lower troposphere below 9 km in the all-sky experiment. Verifications of forecasts against the radiosonde observations show statistically significant reductions of 1% in stddev of error for geopotential height, temperature, and horizontal wind for all-sky experiment between 72- and 120- hr forecast ranges in troposphere in Northern Hemisphere domain. Verifications of forecasts against ECMWF analyses also show small improvements in zonal mean of error stddev for temperature and horizontal wind for all-sky experiment between 72- and 120-hr forecast ranges. This work is planned for operational implementation in the GDPS in Fall 2023.","PeriodicalId":2,"journal":{"name":"ACS Applied Bio Materials","volume":"12 7","pages":""},"PeriodicalIF":4.6000,"publicationDate":"2024-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"ACS Applied Bio Materials","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1175/mwr-d-23-0227.1","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, BIOMATERIALS","Score":null,"Total":0}
引用次数: 0
Abstract
Cloud-affected microwave humidity sounding radiances were excluded from assimilation in 4D-EnVar system of the Global Deterministic Prediction System (GDPS) at Environment and Climate Change Canada (ECCC). This was due to the inability of the current radiative transfer model to consider the scattering effect from frozen hydrometeors at these frequencies. In addition to upgrading the observation operator to RTTOV-SCATT, quality control, bias correction, and 4D-EnVar assimilation components are modified to perform all-sky assimilation of Microwave Humidity Sounder (MHS) channels 2-5 observations over ocean in the GDPS. The input profiles to RTTOV-SCATT are extended to include liquid cloud, ice cloud, and cloud fraction profiles for the simulation and assimilation of MHS observations over water. There is a maximum 35% increase in number of channel 2 assimilated MHS observations with smaller increases for channels 3-5 in the all-sky compared to the clear-sky experiment, mostly because of newly assimilated cloud-affected observations. The stddev of difference between the observed GPSRO refractivity observations and the corresponding simulated values using the background state was reduced in lower troposphere below 9 km in the all-sky experiment. Verifications of forecasts against the radiosonde observations show statistically significant reductions of 1% in stddev of error for geopotential height, temperature, and horizontal wind for all-sky experiment between 72- and 120- hr forecast ranges in troposphere in Northern Hemisphere domain. Verifications of forecasts against ECMWF analyses also show small improvements in zonal mean of error stddev for temperature and horizontal wind for all-sky experiment between 72- and 120-hr forecast ranges. This work is planned for operational implementation in the GDPS in Fall 2023.
期刊介绍:
ACS Applied Bio Materials is an interdisciplinary journal publishing original research covering all aspects of biomaterials and biointerfaces including and beyond the traditional biosensing, biomedical and therapeutic applications.
The journal is devoted to reports of new and original experimental and theoretical research of an applied nature that integrates knowledge in the areas of materials, engineering, physics, bioscience, and chemistry into important bio applications. The journal is specifically interested in work that addresses the relationship between structure and function and assesses the stability and degradation of materials under relevant environmental and biological conditions.