The impact of radar and raingauge sampling errors when calibrating a weather radar

Meteorological Applications - Tập 3 Số 1 - Trang 43-52 - 1996
Alan Seed1, John Nicol1, G. L. Austin1, C. D. Stow1, Stuart Bradley1
1Physics Department, University of Auckland, Private Bag 92019, Auckland, New Zealand

Tóm tắt

AbstractThis paper investigates the impact of sampling errors on the estimation of the parameters of the relation Z = aRb used in the measurement of rainfall (R) from radar reflectivity (Z). Simulation results show that, at levels of sampling errors likely to be observed in real data sets, of the order 100 gauge and radar observation pairs are required to estimate a with an accuracy better than 15% and b better than 10%. Errors in radar rainfall estimates for rain rates less than 15 mm h−1 are insensitive to the Z‐R parameters. High‐resolution measurements from a vertically pointing radar (300 to 400 m above ground level, 1‐minute averages) are compared with raingauge measurements taken at the radar site during a period of widespread rainfall. The radar provided surprisingly poor estimates of rain rates, with mean standard errors of 80% for rain rates less than 2 mm h−1. The auto‐correlations of the residuals in the radar estimates were found to be very low after only 2 minutes, leading to the conclusion that radar estimates of rainfall intensities should be made at a high space/time resolution and then averaged so as to reduce measurement errors arising from sampling problems.

Từ khóa


Tài liệu tham khảo

Atlas D., 1977, Path‐ and area‐ integrated rainfall measurements by microwave attenuation in the 1‐3 cm band, J. Appl. Meterol., 16, 1322, 10.1175/1520-0450(1977)016<1322:PAAIRM>2.0.CO;2

10.1175/1520-0493(1987)115<1053:RBMRRA>2.0.CO;2

10.1002/qj.49710946110

10.1002/qj.49711850503

Fabry F.(1994).Observations and uses of high resolution radar data from precipitation. PhD Thesis McGill University.

10.1002/qj.49711448407

Garstang M.&Emmitt C. D.(1986).Programme for Atmospheric Water Supply Phase 1 1983–1986 Vol. 2: Natural clouds and Rain in Nelspruit. Report to the Water Research Commission. Pretoria South Africa. WRC# 133/2/88.

10.1175/1520-0450(1978)017<0508:ICFAOC>2.0.CO;2

10.1175/1520-0426(1986)003<0536:AIHRR>2.0.CO;2

Joss J. Thams J. C.&Waldvogel A.(1968).The variation of raindrop size distributions at Locarno.Proceedings of International Conference on Cloud Physics Toronto pp.369–373.

Joss J.&Waldvogel A.(1990).Precipitation measurement and hydrology. InRadar in Meteorology: Battan Memorial and 40th Anniversary Radar Meteorology Conference(Atlas D. editor) pp.577–606. American Meteorological Society.

10.1016/0022-1694(92)90026-R

10.1002/qj.49712051906

10.1175/1520-0450(1991)030<1436:OTEOCR>2.0.CO;2

Neter J., 1974, Applied Linear Statistical Models, 842

10.1175/1520-0450(1983)022<1404:OOLIEI>2.0.CO;2

10.1175/1520-0450(1993)032<0050:GPMRBR>2.0.CO;2

10.1175/1520-0450(1994)033<0682:TWPMMF>2.0.CO;2

10.1016/0169-8095(94)90071-X

10.1175/1520-0450(1993)032<1259:ASOSVE>2.0.CO;2

Tees D., 1991, Hydrological Applications of Weather Radar, 296

Zawadzki I.(1984)Factors affecting the precision of radar measurements of rain. Preprints.22nd Conference on Radar Meteorology Boston American Meteorological Society pp.251–256.

Thông tin
Thông tin xuất bản

Meteorological Applications

Tập 3 Số 1

43-52

Thông tin tác giả