TY - JOUR

T1 - The summer 2012 Greenland heat wave

T2 - In situ and remote sensing observations of water vapor isotopic composition during an atmospheric river event

AU - Bonne, Jean-Louis

AU - Steen-Larsen, Hans Christian

AU - Risi, Camille

AU - Werner, Martin

AU - Sodemann, Harald

AU - Lacour, Jean-Lionel

AU - Fettweis, Xavier

AU - Cesana, Grégory

AU - Delmotte, Marc

AU - Cattani, Olivier

AU - Vallelonga, Paul Travis

AU - Kjær, Helle Astrid

AU - Clerbaux, Cathy

AU - Svienbjörndóttir, Árny Erla

AU - Masson-Delmotte, Valérie

PY - 2015/4/1

Y1 - 2015/4/1

N2 - During 7–12 July 2012, extreme moist and warm conditions occurred over Greenland, leading to widespread surface melt. To investigate the physical processes during the atmospheric moisture transport of this event, we study the water vapor isotopic composition using surface in situ observations in Bermuda Island, South Greenland coast (Ivittuut), and northwest Greenland ice sheet (NEEM), as well as remote sensing observations (Infrared Atmospheric Sounding Interferometer (IASI) instrument on board MetOp-A), depicting propagation of similar surface and midtropospheric humidity and δD signals. Simulations using Lagrangian moisture source diagnostic and water tagging in a regional model showed that Greenland was affected by an atmospheric river transporting moisture from the western subtropical North Atlantic Ocean, which is coherent with observations of snow pit impurities deposited at NEEM. At Ivittuut, surface air temperature, humidity, and δD increases are observed. At NEEM, similar temperature increase is associated with a large and long-lasting ∼100‰δD enrichment and ∼15‰ deuterium excess decrease, thereby reaching Ivittuut level. We assess the simulation of this event in two isotope-enabled atmospheric general circulation models (LMDz-iso and ECHAM5-wiso). LMDz-iso correctly captures the timing of propagation for this event identified in IASI data but depict too gradual variations when compared to surface data. Both models reproduce the surface meteorological and isotopic values during the event but underestimate the background deuterium excess at NEEM. Cloud liquid water content parametrization in LMDz-iso poorly impacts the vapor isotopic composition. Our data demonstrate that during this atmospheric river event the deuterium excess signal is conserved from the moisture source to northwest Greenland.

AB - During 7–12 July 2012, extreme moist and warm conditions occurred over Greenland, leading to widespread surface melt. To investigate the physical processes during the atmospheric moisture transport of this event, we study the water vapor isotopic composition using surface in situ observations in Bermuda Island, South Greenland coast (Ivittuut), and northwest Greenland ice sheet (NEEM), as well as remote sensing observations (Infrared Atmospheric Sounding Interferometer (IASI) instrument on board MetOp-A), depicting propagation of similar surface and midtropospheric humidity and δD signals. Simulations using Lagrangian moisture source diagnostic and water tagging in a regional model showed that Greenland was affected by an atmospheric river transporting moisture from the western subtropical North Atlantic Ocean, which is coherent with observations of snow pit impurities deposited at NEEM. At Ivittuut, surface air temperature, humidity, and δD increases are observed. At NEEM, similar temperature increase is associated with a large and long-lasting ∼100‰δD enrichment and ∼15‰ deuterium excess decrease, thereby reaching Ivittuut level. We assess the simulation of this event in two isotope-enabled atmospheric general circulation models (LMDz-iso and ECHAM5-wiso). LMDz-iso correctly captures the timing of propagation for this event identified in IASI data but depict too gradual variations when compared to surface data. Both models reproduce the surface meteorological and isotopic values during the event but underestimate the background deuterium excess at NEEM. Cloud liquid water content parametrization in LMDz-iso poorly impacts the vapor isotopic composition. Our data demonstrate that during this atmospheric river event the deuterium excess signal is conserved from the moisture source to northwest Greenland.

KW - Faculty of Science

KW - Greenland

KW - melt

KW - Remote Sensing

U2 - 10.1002/2014JD022602

DO - 10.1002/2014JD022602

M3 - Journal article

VL - 120

SP - 2970

EP - 2989

JO - Journal of Geophysical Research: Solid Earth

JF - Journal of Geophysical Research: Solid Earth

SN - 0148-0227

IS - 7

ER -