TY - JOUR

T1 - Cloud liquid water path in the sub-Arctic region of Europe as derived from ground-based and space-borne remote observations

AU - Kostsov, Vladimir S.

AU - Kniffka, Anke

AU - Ionov, Dmitry V.

PY - 2018/10/5

Y1 - 2018/10/5

N2 - Tropospheric clouds are a very important component of the climate system and the hydrological cycle in the Arctic and sub-Arctic. Liquid water path (LWP) is one of the key parameters of clouds urgently needed for a variety of studies, including the snow cover and climate modelling at northern latitudes. A joint analysis was made of the LWP values obtained from observations by the SEVIRI satellite instrument and from ground-based observations by the RPG-HATPRO microwave radiometer near St Petersburg, Russia (60° N, 30° E). The time period of selected data sets spans 2 years (December 2012-November 2014) excluding winter months, since the specific requirements for SEVIRI observations restrict measurements at northern latitudes in winter when the solar zenith angle is too large. The radiometer measurement site is located very close to the shore of the Gulf of Finland, and our study has revealed considerable differences between the LWP values obtained by SEVIRI over land and over water areas in the region under investigation. Therefore, special attention was paid to the analysis of the LWP spatial distributions derived from SEVIRI observations at scales from 15 to 150 km in the vicinity of St Petersburg. Good agreement between the daily median LWP values obtained from the SEVIRI and the RPG-HATPRO observations was shown: the rms difference was estimated at 0.016 kg mg-2 for a warm season and 0.048 kg mg-2 for a cold season. Over 7 months (February-May and August-October), the SEVIRI and the RPG-HATPRO instruments revealed similar diurnal variations in LWP, while considerable discrepancies between the diurnal variations obtained by the two instruments were detected in June and July. On the basis of reanalysis data, it was shown that the LWP diurnal cycles are characterised by considerable interannual variability.

AB - Tropospheric clouds are a very important component of the climate system and the hydrological cycle in the Arctic and sub-Arctic. Liquid water path (LWP) is one of the key parameters of clouds urgently needed for a variety of studies, including the snow cover and climate modelling at northern latitudes. A joint analysis was made of the LWP values obtained from observations by the SEVIRI satellite instrument and from ground-based observations by the RPG-HATPRO microwave radiometer near St Petersburg, Russia (60° N, 30° E). The time period of selected data sets spans 2 years (December 2012-November 2014) excluding winter months, since the specific requirements for SEVIRI observations restrict measurements at northern latitudes in winter when the solar zenith angle is too large. The radiometer measurement site is located very close to the shore of the Gulf of Finland, and our study has revealed considerable differences between the LWP values obtained by SEVIRI over land and over water areas in the region under investigation. Therefore, special attention was paid to the analysis of the LWP spatial distributions derived from SEVIRI observations at scales from 15 to 150 km in the vicinity of St Petersburg. Good agreement between the daily median LWP values obtained from the SEVIRI and the RPG-HATPRO observations was shown: the rms difference was estimated at 0.016 kg mg-2 for a warm season and 0.048 kg mg-2 for a cold season. Over 7 months (February-May and August-October), the SEVIRI and the RPG-HATPRO instruments revealed similar diurnal variations in LWP, while considerable discrepancies between the diurnal variations obtained by the two instruments were detected in June and July. On the basis of reanalysis data, it was shown that the LWP diurnal cycles are characterised by considerable interannual variability.

KW - RPG-HATPRO RADIOMETER

KW - CLIMATE-CHANGE IMPACT

KW - DATA SET

KW - MICROWAVE RADIOMETER

KW - SEVIRI

KW - ATMOSPHERE

KW - SATELLITE

KW - TEMPERATURE

KW - VALIDATION

KW - REANALYSIS

UR - http://www.scopus.com/inward/record.url?scp=85054521772&partnerID=8YFLogxK

U2 - 10.5194/amt-11-5439-2018

DO - 10.5194/amt-11-5439-2018

M3 - Article

AN - SCOPUS:85054521772

VL - 11

SP - 5439

EP - 5460

JO - Atmospheric Measurement Techniques

JF - Atmospheric Measurement Techniques

SN - 1867-1381

IS - 10

ER -